Sample records for accident dosimetry systems

  1. Chemical dosimetry system for criticality accidents.

    PubMed

    Miljanić, Saveta; Ilijas, Boris

    2004-01-01

    Ruder Bosković Institute (RBI) criticality dosimetry system consists of a chemical dosimetry system for measuring the total (neutron + gamma) dose, and a thermoluminescent (TL) dosimetry system for a separate determination of the gamma ray component. The use of the chemical dosemeter solution chlorobenzene-ethanol-trimethylpentane (CET) is based on the radiolytic formation of hydrochloric acid, which protonates a pH indicator, thymolsulphonphthalein. The high molar absorptivity of its red form at 552 nm is responsible for a high sensitivity of the system: doses in the range 0.2-15 Gy can be measured. The dosemeter has been designed as a glass ampoule filled with the CET solution and inserted into a pen-shaped plastic holder. For dose determinations, a newly constructed optoelectronic reader has been used. The RBI team took part in the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002, with the CET dosimetry system. For gamma ray dose determination TLD-700 TL detectors were used. The results obtained with CET dosemeter show very good agreement with the reference values.

  2. Nuclear accident dosimetry intercomparison studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sims, C.S.

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shieldedmore » spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry.« less

  3. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b) Nuclear...

  4. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b) Nuclear...

  5. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b) Nuclear...

  6. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b) Nuclear...

  7. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b) Nuclear...

  8. Criticality accident dosimetry with ESR spectroscopy.

    PubMed

    d'Errico, F; Fattibene, P; Onori, S; Pantaloni, M

    1996-01-01

    The suitability of the ESR alanine and sugar detectors for criticality accident dosimetry was experimentally investigated during an intercomparison of dosimetry techniques. Tests were performed irradiating detectors both free-in-air and on-phantom during controlled critcality excursions at the SILENE reactor in Valduc, France. Several grays of absorbed dose were imparted in neutron gamma-ray fields of various relative intensities and spectral distributions. Analysed results confirmed the potential of these systems which can immediately provide an acute dose assessment with an average underestimate of 30%in the various fields. This performance allows for the screening of severely exposed individuals and meets the IAEA recommendations on the early estimate of accident absorbed doses.

  9. 1983 international intercomparison of nuclear accident dosimetry systems at Oak Ridge National Laboratory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Swaja, R.E.; Greene, R.T.; Sims, C.S.

    1985-04-01

    An international intercomparison of nuclear accident dosimetry systems was conducted during September 12-16, 1983, at Oak Ridge National Laboratory (ORNL) using the Health Physics Research Reactor operated in the pulse mode to simulate criticality accidents. This study marked the twentieth in a series of annual accident dosimetry intercomparisons conducted at ORNL. Participants from ten organizations attended this intercomparison and measured neutron and gamma doses at area monitoring stations and on phantoms for three different shield conditions. Results of this study indicate that foil activation techniques are the most popular and accurate method of determining accident-level neutron doses at area monitoringmore » stations. For personnel monitoring, foil activation, blood sodium activation, and thermoluminescent (TL) methods are all capable of providing accurate dose estimates in a variety of radiation fields. All participants in this study used TLD's to determine gamma doses with very good results on the average. Chemical dosemeters were also shown to be capable of yielding accurate estimates of total neutron plus gamma doses in a variety of radiation fields. While 83% of all neutron measurements satisfied regulatory standards relative to reference values, only 39% of all gamma results satisfied corresponding guidelines for gamma measurements. These results indicate that continued improvement in accident dosimetry evaluation and measurement techniques is needed.« less

  10. Technical basis for nuclear accident dosimetry at the Oak Ridge National Laboratory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kerr, G.D.; Mei, G.T.

    The Oak Ridge National Laboratory (ORNL) Environmental, Safety, and Health Emergency Response Organization has the responsibility of providing analyses of personnel exposures to neutrons and gamma rays from a nuclear accident. This report presents the technical and philosophical basis for the dose assessment aspects of the nuclear accident dosimetry (NAD) system at ORNL. The issues addressed are regulatory guidelines, ORNL NAD system components and performance, and the interpretation of dosimetric information that would be gathered following a nuclear accident.

  11. Criticality accident dosimetry systems: an international intercomparison at the SILENE reactor in 2002.

    PubMed

    Médioni, R; Asselineau, B; Verrey, B; Trompier, F; Itié, C; Texier, C; Muller, H; Pelcot, G; Clairand, I; Jacquet, X; Pochat, J L

    2004-01-01

    In criticality accident dosimetry and more generally for high dose measurements, special techniques are used to measure separately the gamma ray and neutron components of the dose. To improve these techniques and to check their dosimetry systems (physical and/or biological), a total of 60 laboratories from 29 countries (America, Europe, Asia) participated in an international intercomparaison, which took place in France from 9 to 21 June 2002, at the SILENE reactor in Valduc and at a pure gamma source in Fontenay-aux-Roses. This intercomparison was jointly organised by the IRSN and the CEA with the help of the NEA/OCDE and was partly supported by the European Communities. This paper describes the aim of this intercomparison, the techniques used by the participants and the two radiation sources and their characteristics. The experimental arrangements of the dosemeters for the irradiations in free air or on phantoms are given. Then the dosimetric quantities measured and reported by the participants are summarised, analysed and compared with the reference values. The present paper concerns only the physical dosimetry and essentially experiments performed on the SILENE facility. The results obtained with the biological dosimetry are published in two other papers of this issue.

  12. The ENEA criticality accident dosimetry system: a contribution to the 2002 international intercomparison at the SILENE reactor.

    PubMed

    Gualdrini, G; Bedogni, R; Fantuzzi, E; Mariotti, F

    2004-01-01

    The present paper summarises the activity carried out at the ENEA Radiation Protection Institute for updating the methodologies employed for the evaluation of the neutron and photon dose to the exposed workers in case of a criticality accident, in the framework of the 'International Intercomparison of Criticality Accident Dosimetry Systems' (Silène reactor, IRSN-CEA-Valduc June 2002). The evaluation of the neutron spectra and the neutron dosimetric quantities relies on activation detectors and on unfolding algorithms. Thermoluminescent detectors are employed for the gamma dose measurement. The work is aimed at accurately characterising the measurement system and, at the same time, testing the algorithms. Useful spectral information were included, based on Monte Carlo simulations, to take into account the potential accident scenarios of practical interest. All along this exercise intercomparison a particular attention was devoted to the 'traceability' of all the experimental and computational parameters and therefore, aimed at an easy treatment by the user.

  13. Radiation accident dosimetry on plastics by EPR spectrometry.

    PubMed

    Trompier, F; Bassinet, C; Clairand, I

    2010-02-01

    In case of acute exposure to ionizing radiation, the dose absorbed by the victims has to be rapidly and accurately assessed in order to choose an appropriate medical treatment. Tooth enamel and bone biopsies measured by EPR spectrometry are often used as dose indicators, due to the good radiation sensitivity and the stability of EPR radiation-sensitive signals. Nevertheless, the invasive sampling of teeth and bones limits the application of this technique to retrospective dosimetry. Therefore, we have investigated an alternative non-invasive methodology. We have surveyed with EPR spectrometry the dosimetric properties of the plastics that can be found in personal effects such as glasses (CR-39, polycarbonate), mobile phones (PMMA, polycarbonate), watches and buttons. Dose response, signal stability and effects of storage conditions were investigated. Significant signal fading limits the use for radiation accident dosimetry. Few plastics present the required characteristics to be used in case of a radiation accident.

  14. International Intercomparison Exercise for Nuclear Accident Dosimetry at the DAF Using GODIVA-IV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hickman, David; Hudson, Becka

    The Nuclear Criticality Safety Program operated under the direction of Dr. Jerry McKamy completed the first NNSA Nuclear Accident Dosimetry exercise on May 27, 2016. Participants in the exercise were from Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), Savanah River Site (SRS), Pacific Northwest National Laboratory (PNNL), US Navy, the Atomic Weapons Establishment (United Kingdom) under the auspices of JOWOG 30, and the Institute for Radiological Protection and Nuclear Safety (France) by special invitation and NCSP memorandum of understanding. This exercise was the culmination of a series of Integral Experiment Requests (IER) thatmore » included the establishment of the Nuclear Criticality Experimental Research Center, (NCERC) the startup of the Godiva Reactor (IER-194), the establishment of a the Nuclear Accident Dosimetry Laboratory (NAD LAB) in Mercury, NV, and the determination of reference dosimetry values for the mixed neutron and photon radiation field of Godiva within NCERC.« less

  15. OSL properties of three commonly available salt brands in India for its use in accident dosimetry

    NASA Astrophysics Data System (ADS)

    Singh, A. K.; Menon, S. N.; Kadam, S. Y.; Koul, D. K.; Datta, D.

    2018-03-01

    Thermally stimulated luminescence (TL) and Optically Stimulated Luminescence (OSL) characterization of three commonly available salt brands in India were undertaken for their application in accident dosimetry. The investigations showed that the luminescence properties differed to some extent with that reported in literature. Dosimetric properties of these salt samples showed that these can be useful in accident dosimetry. Based on the sensitization and fading behaviour of the samples a Single Aliquot Regenerative (SAR) protocol has been proposed for dose estimation.

  16. PNNL Measurement Results for the 2016 Criticality Accident Dosimetry Exercise at the Nevada National Security Stite (IER-148)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rathbone, Bruce A.; Morley, Shannon M.; Stephens, John A.

    The Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimetry intercomparison exercise held at the Nevada National Security Site (NNSS) May 24-27, 2016. The exercise was administered by Lawrence Livermore National Laboratory (LLNL) and consisted of three exposures performed using the Godiva-IV critical assembly housed in the Device Assembly Facility (DAF) located on the NNSS site. The exercise allowed participants to test the ability of their nuclear accident dosimeters to meet the performance criteria in ANSI/HPS N13.3-2013, Dosimetry for Criticality Accidents and to obtain new measurement data for use in revising dose calculation methods and quick sort screeningmore » methods where appropriate. PNNL participated with new prototype Personal Nuclear Accident Dosimeter (PNAD) and Fixed Nuclear Accident Dosimeter (FNAD) designs as well as the existing historical PNAD design. The new prototype designs incorporate optically stimulated luminescence (OSL) dosimeters in place of thermoluminescence dosimeters (TLDs), among other design changes, while retaining the same set of activation foils historically used. The default dose calculation methodology established decades ago for use with activation foils in PNNL PNADs and FNADs was used to calculate neutron dose results for both the existing and prototype dosimeters tested in the exercise. The results indicate that the effective cross sections and/or dose conversion factors used historically need to be updated to accurately measure the operational quantities recommended for nuclear accident dosimetry in ANSI/HPS N13.3-2013 and to ensure PNAD and FNAD performance meets the ANSI/HPS N13.3-2013 performance criteria. The operational quantities recommended for nuclear accident dosimetry are personal absorbed dose, Dp(10), and ambient absorbed dose, D*(10).« less

  17. On the use of new generation mobile phone (smart phone) for retrospective accident dosimetry

    NASA Astrophysics Data System (ADS)

    Lee, J. I.; Chang, I.; Pradhan, A. S.; Kim, J. L.; Kim, B. H.; Chung, K. S.

    2015-11-01

    Optically stimulated luminescence (OSL) characteristics of resistors, inductors and integrated-circuit (IC) chips, extracted from new generation smart phones, were investigated for the purpose of retrospective accident dosimetry. Inductor samples were found to exhibit OSL sensitivity about 5 times and 40 times higher than that of the resistors and the IC chips, respectively. On post-irradiation storage, the resistors exhibited a much higher OSL fading (about 80 % in 36 h as compared to the value 3 min after irradiation) than IC chips (about 20 % after 36 h) and inductors (about 50 % in 36 h). Higher OSL sensitivity, linear dose response (from 8.7 mGy up to 8.9 Gy) and acceptable fading make inductors more attractive for accident dosimetry than widely studied resistors.

  18. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M.

    1998-04-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library ofmore » uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on internal dosimetry, (4) short biographies of the experts, and (5) the aggregated results of their responses.« less

  19. Characterising an aluminium oxide dosimetry system.

    PubMed

    Conheady, Clement F; Gagliardi, Frank M; Ackerly, Trevor

    2015-09-01

    In vivo dosimetry is recommended as a defence-in-depth strategy in radiotherapy treatments and is currently employed by clinics around the world. The characteristics of a new optically stimulated luminescence dosimetry system were investigated for the purpose of replacing an aging thermoluminescence dosimetry system for in vivo dosimetry. The stability of the system was not sufficient to satisfy commissioning requirements and therefore it has not been released into clinical service at this time.

  20. Overview of physical dosimetry methods for triage application integrated in the new European network RENEB.

    PubMed

    Trompier, François; Burbidge, Christopher; Bassinet, Céline; Baumann, Marion; Bortolin, Emanuela; De Angelis, Cinzia; Eakins, Jonathan; Della Monaca, Sara; Fattibene, Paola; Quattrini, Maria Cristina; Tanner, Rick; Wieser, Albrecht; Woda, Clemens

    2017-01-01

    In the EC-funded project RENEB (Realizing the European Network in Biodosimetry), physical methods applied to fortuitous dosimetric materials are used to complement biological dosimetry, to increase dose assessment capacity for large-scale radiation/nuclear accidents. This paper describes the work performed to implement Optically Stimulated Luminescence (OSL) and Electron Paramagnetic Resonance (EPR) dosimetry techniques. OSL is applied to electronic components and EPR to touch-screen glass from mobile phones. To implement these new approaches, several blind tests and inter-laboratory comparisons (ILC) were organized for each assay. OSL systems have shown good performances. EPR systems also show good performance in controlled conditions, but ILC have also demonstrated that post-irradiation exposure to sunlight increases the complexity of the EPR signal analysis. Physically-based dosimetry techniques present high capacity, new possibilities for accident dosimetry, especially in the case of large-scale events. Some of the techniques applied can be considered as operational (e.g. OSL on Surface Mounting Devices [SMD]) and provide a large increase of measurement capacity for existing networks. Other techniques and devices currently undergoing validation or development in Europe could lead to considerable increases in the capacity of the RENEB accident dosimetry network.

  1. DRDC Ottawa Participation in the SILENE Accident Dosimetry Intercomparison Exercise. June 10-21, 2002

    DTIC Science & Technology

    2002-11-01

    of CaF2:Mn and A120 3 TLDs for gamma-ray dosimetry ). In addition, DRDC Ottawa has recently substantially expanded its efforts in radiation dosimetry ...use of any real- time electronic dosimeter. Foils have long been proposed and used for criticality dosimetry (as well as for general monitoring of...ray Dosimetry DRDC Ottawa offers a number (over five) of various thermoluminescence dosimetry ( TLD ) systems. The choice of any particular TLD depends

  2. Czech results at criticality dosimetry intercomparison 2002.

    PubMed

    Frantisek, Spurný; Jaroslav, Trousil

    2004-01-01

    Two criticality dosimetry systems were tested by Czech participants during the intercomparison held in Valduc, France, June 2002. The first consisted of the thermoluminescent detectors (TLDs) (Al-P glasses) and Si-diodes as passive neutron dosemeters. Second, it was studied to what extent the individual dosemeters used in the Czech routine personal dosimetry service can give a reliable estimation of criticality accident exposure. It was found that the first system furnishes quite reliable estimation of accidental doses. For routine individual dosimetry system, no important problems were encountered in the case of photon dosemeters (TLDs, film badge). For etched track detectors in contact with the 232Th or 235U-Al alloy, the track density saturation for the spark counting method limits the upper dose at approximately 1 Gy for neutrons with the energy >1 MeV.

  3. Investigation and Implementation of Commercially Available Optically Stimulated Luminescence Dosimeters for Use in Fixed Nuclear Accident Dosimeter Systems.

    PubMed

    Georgeson, David L; Christiansen, Byron H

    2018-06-01

    Idaho National Laboratory transitioned from an external dosimetry system reliant on thermoluminescent dosimeters to one that uses optically stimulated luminescence dosimeters in 2010. This change not only affected the dosimeters worn by personnel, but those found in the nuclear-accident dosimeters used across Idaho National Laboratory. The elimination of on-site use and processing of thermoluminescent dosimeters impacted Idaho National Laboratory's ability to process nuclear-accident dosimeters in a timely manner. This change in processes drove Idaho National Laboratory to develop an alternative method for fixed nuclear-accident dosimeter gamma-dose analyses. This new method was driven by the need to establish a simple, cost-effective, and rapid-turnaround alternative to the thermoluminescent-dosimeter-based fixed nuclear-accident dosimeter system. An adaptation of existing technologies proved to be the most efficient path to this end. The purpose of this article is to delineate the technical basis for replacing the thermoluminescent dosimeter contained within the Idaho National Laboratory fixed nuclear-accident dosimeter system with optically stimulated luminescence-based Landauer, Inc., nanoDot dosimeters.

  4. Radiation-induced damage analysed by luminescence methods in retrospective dosimetry and emergency response.

    PubMed

    Woda, Clemens; Bassinet, Céline; Trompier, François; Bortolin, Emanuela; Della Monaca, Sara; Fattibene, Paola

    2009-01-01

    The increasing risk of a mass casualty scenario following a large scale radiological accident or attack necessitates the development of appropriate dosimetric tools for emergency response. Luminescence dosimetry has been reliably applied for dose reconstruction in contaminated settlements for several decades and recent research into new materials carried close to the human body opens the possibility of estimating individual doses for accident and emergency dosimetry using the same technique. This paper reviews the luminescence research into materials useful for accident dosimetry and applications in retrospective dosimetry. The properties of the materials are critically discussed with regard to the requirements for population triage. It is concluded that electronic components found within portable electronic devices, such as e.g. mobile phones, are at present the most promising material to function as a fortuitous dosimeter in an emergency response.

  5. Iodine-129 in soils from Northern Ukraine and the retrospective dosimetry of the iodine-131 exposure after the Chernobyl accident.

    PubMed

    Michel, R; Handl, J; Ernst, T; Botsch, W; Szidat, S; Schmidt, A; Jakob, D; Beltz, D; Romantschuk, L D; Synal, H-A; Schnabel, C; López-Gutiérrez, J M

    2005-03-20

    Forty-eight soil profiles down to a depth of 40 cm were taken in Russia and Ukraine in 1995 and 1997, respectively, in order to investigate the feasibility of retrospective dosimetry of the 131I exposure after the Chernobyl accident via the long-lived 129I. The sampling sites covered areas almost not affected by fallout from the Chernobyl accident such as Moscow/Russia and the Zhitomir district in Ukraine as well as the highly contaminated Korosten and Narodici districts in Ukraine. 129I was analyzed by radiochemical neutron activation analysis (RNAA) and accelerator mass spectrometry (AMS). 127I was measured for some profiles by RNAA or ion chromatography (IC). The results for 127I demonstrated large differences in the capabilities of the soils to store iodine over long time spans. The depth profiles of 129I and of 137Cs showed large differences in the migration behavior between the two nuclides but also for each nuclide among the different sampling sites. Though it cannot be quantified how much 129I and 137Cs was lost out of the soil columns into deeper depths, the inventories in the columns were taken as proxies for the total inventories. For 129I, these inventories were at least three orders of magnitude higher than a pre-nuclear value of 0.084+/-0.017 mBq m(-2) derived from a soil profile taken in 1939 in Lutovinovo/Russia. From the samples from Moscow and Zhitomir, a pre-Chernobyl 129I inventory of (44+/-24) mBq m(-2) was determined, limiting the feasibility of 129I retrospective dosimetry to areas where the 129I inventories exceed 100 mBq m(-2). Higher average 129I inventories in the Korosten and Narodici districts of 130 and 848 mBq m(-2), respectively, allowed determination of the 129I fallout due to the Chernobyl accident. Based on the total 129I inventories and on literature data for the atomic ratio of 129I/131I=13.6+/-2.8 for the Chernobyl emissions and on aggregated dose coefficients for 131I, the thyroid exposure due to 131I after the Chernobyl

  6. Considerations regarding the implementation of EPR dosimetry for the population in the vicinity of Semipalatinsk nuclear test site based on experience from other radiation accidents.

    PubMed

    Skvortsov, Valeriy; Ivannikov, Alexander; Tikunov, Dimitri; Stepanenko, Valeriy; Borysheva, Natalie; Orlenko, Sergey; Nalapko, Mikhail; Hoshi, Masaharu

    2006-02-01

    General aspects of applying the method of retrospective dose estimation by electron paramagnetic resonance spectroscopy of human tooth enamel (EPR dosimetry) to the population residing in the vicinity of the Semipalatinsk nuclear test site are analyzed and summarized. The analysis is based on the results obtained during 20 years of investigations conducted in the Medical Radiological Research Center regarding the development and practical application of this method for wide-scale dosimetrical investigation of populations exposed to radiation after the Chernobyl accident and other radiation accidents.

  7. INTEGRATED OPERATIONAL DOSIMETRY SYSTEM AT CERN.

    PubMed

    Dumont, Gérald; Pedrosa, Fernando Baltasar Dos Santos; Carbonez, Pierre; Forkel-Wirth, Doris; Ninin, Pierre; Fuentes, Eloy Reguero; Roesler, Stefan; Vollaire, Joachim

    2017-04-01

    CERN, the European Organization for Nuclear Research, upgraded its operational dosimetry system in March 2013 to be prepared for the first Long Shutdown of CERN's facilities. The new system allows the immediate and automatic checking and recording of the dosimetry data before and after interventions in radiation areas. To facilitate the analysis of the data in context of CERN's approach to As Low As Reasonably Achievable (ALARA), this new system is interfaced to the Intervention Management Planning and Coordination Tool (IMPACT). IMPACT is a web-based application widely used in all CERN's accelerators and their associated technical infrastructures for the planning, the coordination and the approval of interventions (work permit principle). The coupling of the operational dosimetry database with the IMPACT repository allows a direct and almost immediate comparison of the actual dose with the estimations, in addition to enabling the configuration of alarm levels in the dosemeter in function of the intervention to be performed. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Reconstructive dosimetry for cutaneous radiation syndrome

    PubMed Central

    Lima, C.M.A.; Lima, A.R.; Degenhardt, Ä.L.; Valverde, N.J.; Da Silva, F.C.A.

    2015-01-01

    According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry. PMID:26445332

  9. Quantitative evaluation of patient-specific quality assurance using online dosimetry system

    NASA Astrophysics Data System (ADS)

    Jung, Jae-Yong; Shin, Young-Ju; Sohn, Seung-Chang; Min, Jung-Whan; Kim, Yon-Lae; Kim, Dong-Su; Choe, Bo-Young; Suh, Tae-Suk

    2018-01-01

    In this study, we investigated the clinical performance of an online dosimetry system (Mobius FX system, MFX) by 1) dosimetric plan verification using gamma passing rates and dose volume metrics and 2) error-detection capability evaluation by deliberately introduced machine error. Eighteen volumetric modulated arc therapy (VMAT) plans were studied. To evaluate the clinical performance of the MFX, we used gamma analysis and dose volume histogram (DVH) analysis. In addition, to evaluate the error-detection capability, we used gamma analysis and DVH analysis utilizing three types of deliberately introduced errors (Type 1: gantry angle-independent multi-leaf collimator (MLC) error, Type 2: gantry angle-dependent MLC error, and Type 3: gantry angle error). A dosimetric verification comparison of physical dosimetry system (Delt4PT) and online dosimetry system (MFX), gamma passing rates of the two dosimetry systems showed very good agreement with treatment planning system (TPS) calculation. For the average dose difference between the TPS calculation and the MFX measurement, most of the dose metrics showed good agreement within a tolerance of 3%. For the error-detection comparison of Delta4PT and MFX, the gamma passing rates of the two dosimetry systems did not meet the 90% acceptance criterion with the magnitude of error exceeding 2 mm and 1.5 ◦, respectively, for error plans of Types 1, 2, and 3. For delivery with all error types, the average dose difference of PTV due to error magnitude showed good agreement between calculated TPS and measured MFX within 1%. Overall, the results of the online dosimetry system showed very good agreement with those of the physical dosimetry system. Our results suggest that a log file-based online dosimetry system is a very suitable verification tool for accurate and efficient clinical routines for patient-specific quality assurance (QA).

  10. Mathematical methods in biological dosimetry: the 1996 Iranian accident.

    PubMed

    Voisin, P; Assaei, R G; Heidary, A; Varzegar, R; Zakeri, F; Durand, V; Sorokine-Durm, I

    2000-11-01

    To report 18 months of cytogenetic follow-up for an Iranian worker accidentally overexposed to 192Ir, the mathematical extrapolation and comparison with clinical data. Unstable chromosome aberrations were measured using conventional cytogenetic tests by French and Iranian biological dosimetry laboratories on five occasions after the exposure. The decrease in dicentrics over time was analysed mathematically. In addition, Dolphin and Qdr extrapolations were applied to the data to check the exposure estimates. FISH determination of translocation yields was performed twice by the French laboratory and the results compared with the Dolphin and Qdr corrected values. Dose estimates based on dicentrics decreased from 3.1 +/- 0.4 Gy at 5 days after the accident to 0.8 +/- 0.2 Gy at 529 days. This could be fitted by double-exponential regression with an inflexion point between rapid and slow decrease of dicentrics after about 40 days. Dose estimates of 3.4 +/- 0.4 Gy for the Qdr model and 3.6 +/- 0.5 Gy for the Dolphin model were calculated during the post-exposure period and were remarkably stable. FISH translocation data at 26 and 61 days appeared consistent with the Dolphin and Qdr estimates. Dose correction by the Qdr and Dolphin models and translocation scoring appeared consistent with the clinical data and provided better information about the radiation injury than did crude estimates from dicentric scoring alone. Estimation by the Dolphin model of the irradiated fraction of the body seemed unreliable: it correlated better with the fraction of originally irradiated lymphocytes.

  11. Radiotherapy dosimetry using a commercial OSL system.

    PubMed

    Viamonte, A; da Rosa, L A R; Buckley, L A; Cherpak, A; Cygler, J E

    2008-04-01

    A commercial optically stimulated luminescence (OSL) system developed for radiation protection dosimetry by Landauer, Inc., the InLight microStar reader, was tested for dosimetry procedures in radiotherapy. The system uses carbon-doped aluminum oxide, Al2O3:C, as a radiation detector material. Using this OSL system, a percent depth dose curve for 60Co gamma radiation was measured in solid water. Field size and SSD dependences of the detector response were also evaluated. The dose response relationship was investigated between 25 and 400 cGy. The decay of the response with time following irradiation and the energy dependence of the Al2O3:C OSL detectors were also measured. The results obtained using OSL dosimeters show good agreement with ionization chamber and diode measurements carried out under the same conditions. Reproducibility studies show that the response of the OSL system to repeated exposures is 2.5% (1sd), indicating a real possibility of applying the Landauer OSL commercial system for radiotherapy dosimetric procedures.

  12. Fundamentals of materials, techniques and instrumentation for OSL and FNTD dosimetry

    NASA Astrophysics Data System (ADS)

    Akselrod, M. S.

    2013-02-01

    The optically stimulated luminescence (OSL) technique has already become a successful commercial tool in personal radiation dosimetry, medical dosimetry, diagnostic imaging, geological and archeological dating. This review briefly describes the history and fundamental principles of OSL materials, methods and instrumentation. The advantages of OSL technology and instrumentation in comparison with thermoluminescent technique are analyzed. Progress in material and detector engineering has allowed new and promising developments regarding OSL applications in the medical field. Special attention is dedicated to Al2O3:C as a material of choice for many dosimetric applications including fiberoptic OSL/RL sensors with diameters as small as 300 μm. A new RL/OSL fiberoptic system has a high potential for in vivo and in vitro dosimetry in both radiation therapy and diagnostic mammography. Different aspects of instrumentation, data processing algorithms, post-irradiation and real-time measurements are described. The next technological breakthrough was done with Fluorescent Nuclear Track detectors (FNTD) that has some important advantages in measuring fast neutron and high energy heavy charge particles that became the latest tool in radiation therapy. New Mg-doped aluminum oxide crystals and novel type of imaging instrumentation for FNTD technology were engineered and successfully demonstrated for occupational and accident dosimetry, for medical dosimetry and radiobiological research.

  13. A practical three-dimensional dosimetry system for radiation therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guo Pengyi; Adamovics, John; Oldham, Mark

    2006-10-15

    There is a pressing need for a practical three-dimensional (3D) dosimetry system, convenient for clinical use, and with the accuracy and resolution to enable comprehensive verification of the complex dose distributions typical of modern radiation therapy. Here we introduce a dosimetry system that can achieve this challenge, consisting of a radiochromic dosimeter (PRESAGE trade mark sign ) and a commercial optical computed tomography (CT) scanning system (OCTOPUS trade mark sign ). PRESAGE trade mark sign is a transparent material with compelling properties for dosimetry, including insensitivity of the dose response to atmospheric exposure, a solid texture negating the need formore » an external container (reducing edge effects), and amenability to accurate optical CT scanning due to radiochromic optical contrast as opposed to light-scattering contrast. An evaluation of the performance and viability of the PRESAGE trade mark sign /OCTOPUS, combination for routine clinical 3D dosimetry is presented. The performance of the two components (scanner and dosimeter) was investigated separately prior to full system test. The optical CT scanner has a spatial resolution of {<=}1 mm, geometric accuracy within 1 mm, and high reconstruction linearity (with a R{sup 2} value of 0.9979 and a standard error of estimation of {approx}1%) relative to independent measurement. The overall performance of the PRESAGE trade mark sign /OCTOPUS system was evaluated with respect to a simple known 3D dose distribution, by comparison with GAFCHROMIC[reg] EBT film and the calculated dose from a commissioned planning system. The 'measured' dose distribution in a cylindrical PRESAGE trade mark sign dosimeter (16 cm diameter and 11 cm height) was determined by optical-CT, using a filtered backprojection reconstruction algorithm. A three-way Gamma map comparison (4% dose difference and 4 mm distance to agreement), between the PRESAGE trade mark sign , EBT and calculated dose distributions, showed

  14. Clinical implementation and rapid commissioning of an EPID based in-vivo dosimetry system.

    PubMed

    Hanson, Ian M; Hansen, Vibeke N; Olaciregui-Ruiz, Igor; van Herk, Marcel

    2014-10-07

    Using an Electronic Portal Imaging Device (EPID) to perform in-vivo dosimetry is one of the most effective and efficient methods of verifying the safe delivery of complex radiotherapy treatments. Previous work has detailed the development of an EPID based in-vivo dosimetry system that was subsequently used to replace pre-treatment dose verification of IMRT and VMAT plans. Here we show that this system can be readily implemented on a commercial megavoltage imaging platform without modification to EPID hardware and without impacting standard imaging procedures. The accuracy and practicality of the EPID in-vivo dosimetry system was confirmed through a comparison with traditional TLD in-vivo measurements performed on five prostate patients.The commissioning time required for the EPID in-vivo dosimetry system was initially prohibitive at approximately 10 h per linac. Here we present a method of calculating linac specific EPID dosimetry correction factors that allow a single energy specific commissioning model to be applied to EPID data from multiple linacs. Using this method reduced the required per linac commissioning time to approximately 30 min.The validity of this commissioning method has been tested by analysing in-vivo dosimetry results of 1220 patients acquired on seven linacs over a period of 5 years. The average deviation between EPID based isocentre dose and expected isocentre dose for these patients was (-0.7  ±  3.2)%.EPID based in-vivo dosimetry is now the primary in-vivo dosimetry tool used at our centre and has replaced nearly all pre-treatment dose verification of IMRT treatments.

  15. Clinical implementation and rapid commissioning of an EPID based in-vivo dosimetry system

    NASA Astrophysics Data System (ADS)

    Hanson, Ian M.; Hansen, Vibeke N.; Olaciregui-Ruiz, Igor; van Herk, Marcel

    2014-10-01

    Using an Electronic Portal Imaging Device (EPID) to perform in-vivo dosimetry is one of the most effective and efficient methods of verifying the safe delivery of complex radiotherapy treatments. Previous work has detailed the development of an EPID based in-vivo dosimetry system that was subsequently used to replace pre-treatment dose verification of IMRT and VMAT plans. Here we show that this system can be readily implemented on a commercial megavoltage imaging platform without modification to EPID hardware and without impacting standard imaging procedures. The accuracy and practicality of the EPID in-vivo dosimetry system was confirmed through a comparison with traditional TLD in-vivo measurements performed on five prostate patients. The commissioning time required for the EPID in-vivo dosimetry system was initially prohibitive at approximately 10 h per linac. Here we present a method of calculating linac specific EPID dosimetry correction factors that allow a single energy specific commissioning model to be applied to EPID data from multiple linacs. Using this method reduced the required per linac commissioning time to approximately 30 min. The validity of this commissioning method has been tested by analysing in-vivo dosimetry results of 1220 patients acquired on seven linacs over a period of 5 years. The average deviation between EPID based isocentre dose and expected isocentre dose for these patients was (-0.7  ±  3.2)%. EPID based in-vivo dosimetry is now the primary in-vivo dosimetry tool used at our centre and has replaced nearly all pre-treatment dose verification of IMRT treatments.

  16. Protocol for emergency EPR dosimetry in fingernails

    USDA-ARS?s Scientific Manuscript database

    There is an increased need for after-the fact dosimetry because of the high risk of radiation exposures due to terrorism or accidents. In case of such an event, a method is needed to make measurements of dose in a large number of individuals rapidly and with sufficient accuracy to facilitate effect...

  17. Short-Term Medical Consequences of the Chernobyl Nuclear Accident: Lessons for the Future

    PubMed Central

    Gale, Robert Peter

    1988-01-01

    The author of this article discusses the world's most serious nuclear accident to date: the Chernobyl nuclear accident of April 1986. His major focus is on the short-term medical consequences of the accident, including reduction of exposure to persons at risk, evaluation of persons potentially affected, dosimetry, and specific medical interventions. PMID:21253129

  18. In Vitro Exposure Systems and Dosimetry Assessment Tools ...

    EPA Pesticide Factsheets

    In 2009, the passing of The Family Smoking Prevention and Tobacco Control Act facilitated the establishment of the FDA Center for Tobacco Products (CTP) and gave it regulatory authority over the marketing, manufacture and distribution of tobacco products, including those termed “modified risk”. On 4-6 April 2016, the Institute for In Vitro Sciences, Inc. (IIVS) convened a workshop conference titled “In Vitro Exposure Systems and Dosimetry Assessment Tools for Inhaled Tobacco Products” to bring together stakeholders representing regulatory agencies, academia, and industry to address the research priorities articulated by the FDA CTP. Specific topics were covered to assess the status of current in vitro smoke and aerosol/vapor exposure systems, as well as the various approaches and challenges to quantifying the complex exposures, in in vitro pulmonary models developed for evaluating adverse pulmonary events resulting from tobacco product exposures. The four core topics covered were, 1) Tobacco Smoke And E-Cigarette Aerosols, 2) Air-Liquid Interface-In Vitro Exposure Systems, 3) Dosimetry Approaches For Particles And Vapors; In Vitro Dosimetry Determinations and 4) Exposure Microenvironment/Physiology Of Cells. The two and a half day workshop included presentations from 20 expert speakers, poster sessions, networking discussions, and breakout sessions which identified key findings and provided recommendations to advance these technologies. Here, we will re

  19. Canadian Cytogenetic Emergency network (CEN) for biological dosimetry following radiological/nuclear accidents.

    PubMed

    Miller, Susan M; Ferrarotto, Catherine L; Vlahovich, Slavica; Wilkins, Ruth C; Boreham, Douglas R; Dolling, Jo-Anna

    2007-07-01

    To test the ability of the cytogenetic emergency network (CEN) of laboratories, currently under development across Canada, to provide rapid biological dosimetry using the dicentric assay for triage assessment, that could be implemented in the event of a large-scale radiation/nuclear emergency. A workshop was held in May 2004 in Toronto, Canada, to introduce the concept of CEN and recruit clinical cytogenetic laboratories at hospitals across the country. Slides were prepared for dicentric assay analysis following in vitro irradiation of blood to a range of gamma-ray doses. A minimum of 50 metaphases per slide were analyzed by 41 people at 22 different laboratories to estimate the exposure level. Dose estimates were calculated based on a dose response curve generated at Health Canada. There were a total of 104 dose estimates and 96 (92.3%) of them fell within the expected range using triage scoring criteria. Half of the laboratories analyzed 50 metaphases in dosimetry. When this network is fully operational, it will be the first of its kind in Canada able to respond to radiological/nuclear emergencies by providing triage quality biological dosimetry for a large number of samples. This network represents an alternate expansion of existing international emergency biological dosimetry cytogenetic networks.

  20. Advanced dosimetry systems for the space transport and space station

    NASA Technical Reports Server (NTRS)

    Wailly, L. F.; Schneider, M. F.; Clark, B. C.

    1972-01-01

    Advanced dosimetry system concepts are described that will provide automated and instantaneous measurement of dose and particle spectra. Systems are proposed for measuring dose rate from cosmic radiation background to greater than 3600 rads/hr. Charged particle spectrometers, both internal and external to the spacecraft, are described for determining mixed field energy spectra and particle fluxes for both real time onboard and ground-based computer evaluation of the radiation hazard. Automated passive dosimetry systems consisting of thermoluminescent dosimeters and activation techniques are proposed for recording the dose levels for twelve or more crew members. This system will allow automatic onboard readout and data storage of the accumulated dose and can be transmitted to ground after readout or data records recovered with each crew rotation.

  1. The Mayak Worker Dosimetry System (Mwds-2013): An Introduction to The Documentation

    DOE PAGES

    Napier, B. A.

    2017-03-17

    The reconstruction of radiation doses to Mayak Production Association workers in central Russia supports radiation epidemiological studies for the U.S.-Russian Joint Coordinating Committee on Radiation Effects Research. The most recent version of the dosimetry was performed with the Mayak Worker Dosimetry System-2013. Here, this introduction outlines the logic and general content of the series of articles presented in this issue of Radiation Protection Dosimetry. The articles summarize the models, describe the basis for most of the key decisions made in developing the models and present an overview of the results.

  2. The Mayak Worker Dosimetry System (Mwds-2013): An Introduction to The Documentation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Napier, B. A.

    The reconstruction of radiation doses to Mayak Production Association workers in central Russia supports radiation epidemiological studies for the U.S.-Russian Joint Coordinating Committee on Radiation Effects Research. The most recent version of the dosimetry was performed with the Mayak Worker Dosimetry System-2013. Here, this introduction outlines the logic and general content of the series of articles presented in this issue of Radiation Protection Dosimetry. The articles summarize the models, describe the basis for most of the key decisions made in developing the models and present an overview of the results.

  3. A neutron dosemeter for nuclear criticality accidents.

    PubMed

    d'Errico, F; Curzio, G; Ciolini, R; Del Gratta, A; Nath, R

    2004-01-01

    A neutron dosemeter which offers instant read-out has been developed for nuclear criticality accidents. The system is based on gels containing emulsions of superheated dichlorodifluoromethane droplets, which vaporise into bubbles upon neutron irradiation. The expansion of these bubbles displaces an equivalent volume of gel into a graduated pipette, providing an immediate measure of the dose. Instant read-out is achieved using an array of transmissive optical sensors which consist of coupled LED emitters and phototransistor receivers. When the gel displaced in the pipette crosses the sensing region of the photomicrosensors, it generates a signal collected on a computer through a dedicated acquisition board. The performance of the device was tested during the 2002 International Accident Dosimetry Intercomparison in Valduc, France. The dosemeter was able to follow the initial dose gradient of a simulated accident, providing accurate values of neutron kerma; however, the emulsion was rapidly depleted of all its drops. A model of the depletion effects was developed and it indicates that an adequate dynamic range of the dose response can be achieved by using emulsions of smaller droplets.

  4. Computer Aided Dosimetry and Verification of Exposure to Radiation

    NASA Astrophysics Data System (ADS)

    Waller, Edward; Stodilka, Robert Z.; Leach, Karen E.; Lalonde, Louise

    2002-06-01

    In the timeframe following the September 11th attacks on the United States, increased emphasis has been placed on Chemical, Biological, Radiological and Nuclear (CBRN) preparedness. Of prime importance is rapid field assessment of potential radiation exposure to Canadian Forces field personnel. This work set up a framework for generating an 'expert' computer system for aiding and assisting field personnel in determining the extent of radiation insult to military personnel. Data was gathered by review of the available literature, discussions with medical and health physics personnel having hands-on experience dealing with radiation accident victims, and from experience of the principal investigator. Flow charts and generic data fusion algorithms were developed. Relationships between known exposure parameters, patient interview and history, clinical symptoms, clinical work-ups, physical dosimetry, biological dosimetry, and dose reconstruction as critical data indicators were investigated. The data obtained was examined in terms of information theory. A main goal was to determine how best to generate an adaptive model (i.e. when more data becomes available, how is the prediction improved). Consideration was given to determination of predictive algorithms for health outcome. In addition. the concept of coding an expert medical treatment advisor system was developed (U)

  5. Introduction of a deformable x-ray CT polymer gel dosimetry system

    NASA Astrophysics Data System (ADS)

    Maynard, E.; Heath, E.; Hilts, M.; Jirasek, A.

    2018-04-01

    This study introduces the first 3D deformable dosimetry system based on x-ray computed tomography (CT) polymer gel dosimetry and establishes the setup reproducibility, deformation characteristics and dose response of the system. A N-isopropylacrylamide (NIPAM)-based gel formulation optimized for x-ray CT gel dosimetry was used, with a latex balloon serving as the deformable container and low-density polyethylene and polyvinyl alcohol providing additional oxygen barrier. Deformable gels were irradiated with a 6 MV calibration pattern to determine dosimetric response and a dosimetrically uniform plan to determine the spatial uniformity of the response. Wax beads were added to each gel as fiducial markers to track the deformation and setup of the gel dosimeters. From positions of the beads on CT images the setup reproducibility and the limits and reproducibility of gel deformation were determined. Comparison of gel measurements with Monte Carlo dose calculations found excellent dosimetric accuracy, comparable to that of an established non-deformable dosimetry system, with a mean dose discrepancy of 1.5% in the low-dose gradient region and a gamma pass rate of 97.9% using a 3%/3 mm criterion. The deformable dosimeter also showed good overall spatial dose uniformity throughout the dosimeter with some discrepancies within 20 mm of the edge of the container. Tracking of the beads within the dosimeter found that sub-millimetre setup accuracy is achievable with this system. The dosimeter was able to deform and relax when externally compressed by up to 30 mm without sustaining any permanent damage. Internal deformations in 3D produced average marker movements of up to 12 mm along the direction of compression. These deformations were also shown to be reproducible over 100 consecutive deformations. This work has established several important characteristics of a new deformable dosimetry system which shows promise for future clinical applications, including the

  6. MO-B-BRB-04: 3D Dosimetry in End-To-End Dosimetry QA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ibbott, G.

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by themore » development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data

  7. Consequences of the radiation accident at the Mayak production association in 1957 (the 'Kyshtym Accident').

    PubMed

    Akleyev, A V; Krestinina, L Yu; Degteva, M O; Tolstykh, E I

    2017-09-01

    This paper presents an overview of the nuclear accident that occurred at the Mayak Production Association (PA) in the Russian Federation on 29 September 1957, often referred to as 'Kyshtym Accident', when 20 MCi (740 PBq) of radionuclides were released by a chemical explosion in a radioactive waste storage tank. 2 MCi (74 PBq) spread beyond the Mayak PA site to form the East Urals Radioactive Trace (EURT). The paper describes the accident and gives brief characteristics of the efficacy of the implemented protective measures that made it possible to considerably reduce doses to the exposed population. The paper also provides retrospective dosimetry estimates for the members of the EURT Cohort (EURTC) which comprises approximately 21 400 people. During the first two years after the accident a decrease in the group average leukocyte (mainly due to neutrophils and lymphocytes) and thrombocyte count was observed in the population. At later dates an increased excess relative risk of solid cancer incidence and mortality was found in the EURTC.

  8. IMRT verification using a radiochromic/optical-CT dosimetry system

    NASA Astrophysics Data System (ADS)

    Oldham, Mark; Guo, Pengyi; Gluckman, Gary; Adamovics, John

    2006-12-01

    This work represents our first experiences relating to IMRT verification using a relatively new 3D dosimetry system consisting of a PRESAGETM dosimeter (Heuris Inc, Pharma LLC) and an optical-CT scanning system (OCTOPUSTM TM MGS Inc). This work builds in a step-wise manner on prior work in our lab.

  9. Clinical application of the OneDose™ Patient Dosimetry System for total body irradiation

    NASA Astrophysics Data System (ADS)

    Best, S.; Ralston, A.; Suchowerska, N.

    2005-12-01

    The OneDose™ Patient Dosimetry System (Sicel Technologies) is a new dosimeter based on metal oxide semiconductor field-effect transistor technology and designed for the in vivo measurement of patient dose during radiotherapy. In vivo dosimetry for total body irradiation (TBI) is challenging due to the extended treatment distance, low dose rates and beam spoilers. Phantom results confirm the suitability of the dosimeter for TBI in terms of inherent build-up, post-irradiation fading, accuracy, reproducibility, linearity and temperature dependence. Directional dependence is significant and should be taken into account. The OneDose™ dosimeters were also trialed in vivo for two TBI patients and the dose measured compared to conventional dosimeter measurements using an ionization chamber and thermoluminescent dosimeters (TLD), with agreement to within 2.2% and 3.9%, respectively. Phantom and patient results confirm that the OneDose™ patient dosimetry system is a practical and convenient alternative to TLDs for TBI in vivo dosimetry. For increased confidence in results with this dosimeter, we recommend that two dosimeters be used for each site of interest.

  10. Clinical application of the OneDose Patient Dosimetry System for total body irradiation.

    PubMed

    Best, S; Ralston, A; Suchowerska, N

    2005-12-21

    The OneDose Patient Dosimetry System (Sicel Technologies) is a new dosimeter based on metal oxide semiconductor field-effect transistor technology and designed for the in vivo measurement of patient dose during radiotherapy. In vivo dosimetry for total body irradiation (TBI) is challenging due to the extended treatment distance, low dose rates and beam spoilers. Phantom results confirm the suitability of the dosimeter for TBI in terms of inherent build-up, post-irradiation fading, accuracy, reproducibility, linearity and temperature dependence. Directional dependence is significant and should be taken into account. The OneDose dosimeters were also trialed in vivo for two TBI patients and the dose measured compared to conventional dosimeter measurements using an ionization chamber and thermoluminescent dosimeters (TLD), with agreement to within 2.2% and 3.9%, respectively. Phantom and patient results confirm that the OneDose patient dosimetry system is a practical and convenient alternative to TLDs for TBI in vivo dosimetry. For increased confidence in results with this dosimeter, we recommend that two dosimeters be used for each site of interest.

  11. Experimental analysis of a novel and low-cost pin photodiode dosimetry system for diagnostic radiology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nazififard, Mohammad, E-mail: nazifi@kashanu.ac.ir; Mahmoudieh, Afshin; Suh, Kune Y.

    Silicon PIN photodiode has recently found broad and exciting applications in the ionizing radiation dosimetry. In this study a compact and novel dosimetry system using a commercially available PIN photodiode (BPW34) has been experimentally tested for diagnostic radiology. The system was evaluated with clinical beams routinely used for diagnostic radiology and calibrated using a secondary reference standard. Measured dose with PIN photodiode (Air Kerma) varied from 10 to 430 μGy for tube voltages from 40 to 100 kVp and tube current from 0.4 to 40 mAs. The minimum detectable organ dose was estimated to be 10 μGy with 20% uncertainty.more » Results showed a linear correlation between the PIN photodiode readout and dose measured with standard dosimeters spanning doses received. The present dosimetry system having advantages of suitable sensitivity with immediate readout of dose values, low cost, and portability could be used as an alternative to passive dosimetry system such as thermoluminescent dosimeter for dose measurements in diagnostic radiology.« less

  12. Experimental active and passive dosimetry systems for the NASA Skylab program

    NASA Technical Reports Server (NTRS)

    Schneider, M. F.; Janni, J. F.; Ainsworth, G. C.

    1972-01-01

    Active and passive dosimetry instrumentation to measure absorbed dose, charged particle spectra, and linear energy transfer spectra inside the command module and orbital workshop on the Skylab program were developed and tested. The active dosimetry system consists of one integral unit employing both a tissue equivalent ionization chamber and silicon solid state detectors. The instrument measures dose rates from 0.2 millirad/hour to 25 rads/hour, linear energy transfer spectra from 2.8 to 42.4 Kev/micron, and the proton and alpha particle energy spectra from 0.5 to 75 Mev. The active dosimeter is equipped with a portable radiation sensor for use in astronaut on-body and spacecraft shielding surveys during passage of the Skylab through significant space radiations. Data are transmitted in real time or are recorded by onboard spacecraft tape recorder for rapid evaluation of the radiation levels. The passive dosimetry systems consist of twelve (12) hard-mounted assemblies, each containing a variety of passive radiation sensors which are recoverable at the end of the mission for analysis.

  13. 2004 Missouri state highway system : traffic accident statistics

    DOT National Transportation Integrated Search

    2005-06-27

    The following summary of traffic accidents represents only those accidents that have occurred on the State Highway : System of Missouri in 2004. The information contained in this publication is a summary of the accident reports : provided to the Miss...

  14. 1999 Missouri state highway system : traffic accident statistics

    DOT National Transportation Integrated Search

    2001-01-17

    The following summary of traffic accidents represents only those accidents that have occurred on the State : Highway System of Missouri in 1999. The information contained in this publication is a summary of the accident : reports provided to the Miss...

  15. 2001 Missouri state highway system : traffic accident statistics

    DOT National Transportation Integrated Search

    2002-09-30

    The following summary of traffic accidents represents only those accidents that have occurred on the State : Highway System of Missouri in 2001. The information contained in this publication is a summary of the accident : reports provided to the Miss...

  16. 2000 Missouri state highway system : traffic accident statistics

    DOT National Transportation Integrated Search

    2001-10-25

    The following summary of traffic accidents represents only those accidents that have occurred on the State : Highway System of Missouri in 2000. The information contained in this publication is a summary of the accident : reports provided to the Miss...

  17. 2002 Missouri state highway system : traffic accident statistics

    DOT National Transportation Integrated Search

    2003-07-02

    The following summary of traffic accidents represents only those accidents that have occurred on the State Highway : System of Missouri in 2002. The information contained in this publication is a summary of the accident reports : provided to the Miss...

  18. 2005 Missouri state highway system : traffic accident statistics

    DOT National Transportation Integrated Search

    2006-08-31

    The following summary of traffic accidents represents only those accidents that have occurred on the State Highway : System of Missouri in 2005. The information contained in this publication is a summary of the accident reports : provided to the Miss...

  19. 2003 Missouri state highway system : traffic accident statistics

    DOT National Transportation Integrated Search

    2004-08-12

    The following summary of traffic accidents represents only those accidents that have occurred on the State Highway : System of Missouri in 2003. The information contained in this publication is a summary of the accident reports : provided to the Miss...

  20. Verification of an on line in vivo semiconductor dosimetry system for TBI with two TLD procedures.

    PubMed

    Sánchez-Doblado, F; Terrón, J A; Sánchez-Nieto, B; Arráns, R; Errazquin, L; Biggs, D; Lee, C; Núñez, L; Delgado, A; Muñiz, J L

    1995-01-01

    This work presents the verification of an on line in vivo dosimetry system based on semiconductors. Software and hardware has been designed to convert the diode signal into absorbed dose. Final verification was made in the form of an intercomparison with two independent thermoluminiscent (TLD) dosimetry systems, under TBI conditions.

  1. EPR dosimetry in a mixed neutron and gamma radiation field.

    PubMed

    Trompier, F; Fattibene, P; Tikunov, D; Bartolotta, A; Carosi, A; Doca, M C

    2004-01-01

    Suitability of Electron Paramagnetic Resonance (EPR) spectroscopy for criticality dosimetry was evaluated for tooth enamel, mannose and alanine pellets during the 'international intercomparison of criticality dosimetry techniques' at the SILENE reactor held in Valduc in June 2002, France. These three materials were irradiated in neutron and gamma-ray fields of various relative intensities and spectral distributions in order to evaluate their neutron sensitivity. The neutron response was found to be around 10% for tooth enamel, 45% for mannose and between 40 and 90% for alanine pellets according their type. According to the IAEA recommendations on the early estimate of criticality accident absorbed dose, analyzed results show the EPR potentiality and complementarity with regular criticality techniques.

  2. Why System Safety Professionals Should Read Accident Reports

    NASA Technical Reports Server (NTRS)

    Holloway, C. M.; Johnson, C. W.

    2006-01-01

    System safety professionals, both researchers and practitioners, who regularly read accident reports reap important benefits. These benefits include an improved ability to separate myths from reality, including both myths about specific accidents and ones concerning accidents in general; an increased understanding of the consequences of unlikely events, which can help inform future designs; a greater recognition of the limits of mathematical models; and guidance on potentially relevant research directions that may contribute to safety improvements in future systems.

  3. Use of aspartame-based sweetener tablets in emergency dosimetry using EPR.

    PubMed

    Maghraby, A; Salama, E

    2010-06-01

    Accident dosimetry aims to evaluate the unplanned radiation doses delivered to individuals through one of the objects exist in the area of the accident. The gamma dose response of free radicals generated in irradiated aspartame tablets and its usability for emergency dosimetry was studied. EPR spectra of unirradiated and irradiated aspartame-based sweetener were recorded. Two signals arise after irradiating, S(1) at g (S(1)) = 2.00229 +/- 0.00097 and S(2) at g (S(2)) = 2.00262 +/- 0.00088. Some EPR parameters were studied for radiation-induced radicals in aspartame sweeteners tablets, such as the microwave saturation behaviour, the effect of magnetic field modulation amplitude on the peak-to-peak height and peak-to-peak line width for both of S(1) and S(2). Responses of S(1) and S(2) to different radiation doses were studied and resulted in linear relationships, radicals persistence curves were plotted over a 49-d storage period. It was found that Aspartame sweeteners tablets are useful in the range from 0.96 to 39.96 Gy. Radiation-induced radicals possess reasonable stability.

  4. Evaluation of Effective Sources in Uncertainty Measurements of Personal Dosimetry by a Harshaw TLD System

    PubMed Central

    Hosseini Pooya, SM; Orouji, T

    2014-01-01

    Background: The accurate results of the individual doses in personal dosimety which are reported by the service providers in personal dosimetry are very important. There are national / international criteria for acceptable dosimetry system performance. Objective: In this research, the sources of uncertainties are identified, measured and calculated in a personal dosimetry system by TLD. Method: These sources are included; inhomogeneity of TLDs sensitivity, variability of TLD readings due to limited sensitivity and background, energy dependence, directional dependence, non-linearity of the response, fading, dependent on ambient temperature / humidity and calibration errors, which may affect on the dose responses. Some parameters which influence on the above sources of uncertainty are studied for Harshaw TLD-100 cards dosimeters as well as the hot gas Harshaw 6600 TLD reader system. Results: The individual uncertainties of each sources was measured less than 6.7% in 68% confidence level. The total uncertainty was calculated 17.5% with 95% confidence level. Conclusion: The TLD-100 personal dosimeters as well as the Harshaw TLD-100 reader 6600 system show the total uncertainty value which is less than that of admissible value of 42% for personal dosimetry services. PMID:25505769

  5. Dose evaluation in criticality accidents using response of Panasonic TL personal dosemeters (UD-809/UD-802).

    PubMed

    Zeyrek, C T; Gündüz, H

    2012-09-01

    This study gives the results of dosimetry measurements carried out in the Silène reactor at Valduc (France) with neutron and photon personal thermoluminescence dosemeters (TLDs) in mixed neutron and gamma radiation fields, in the frame of the international accident dosimetry intercomparison programme in 2002. The intercomparison consisted of a series of three irradiation scenarios. The scenarios took place at the Valduc site (France) by using the Silène experimental reactor. For neutron and photon dosimetry, Panasonic model UD-809 and UD-802 personal TLDs were used together.

  6. Calibration of a mosfet detection system for 6-MV in vivo dosimetry.

    PubMed

    Scalchi, P; Francescon, P

    1998-03-01

    dosimetry within 5%. Ionization chamber and MOSFET midplane dosimetry in inhomogeneous phantoms are in agreement within 2%. MOSFET characteristics are suitable for the in vivo dosimetry relevant to 6-MV treatments, both in normal and TBI setup. The TBI midplane dosimetry using MOSFETs is valid also in the presence of the lung, which is the most critical organ, and allows verifying that calculation of the lung attenuator thicknesses based only on the density is not correct. Our MOSFET dosimetry system can be used also to determine the surface dose by using the water-equivalent depth and extrapolation methods. This procedure depends on the field size used.

  7. Accident/Mishap Investigation System

    NASA Technical Reports Server (NTRS)

    Keller, Richard; Wolfe, Shawn; Gawdiak, Yuri; Carvalho, Robert; Panontin, Tina; Williams, James; Sturken, Ian

    2007-01-01

    InvestigationOrganizer (IO) is a Web-based collaborative information system that integrates the generic functionality of a database, a document repository, a semantic hypermedia browser, and a rule-based inference system with specialized modeling and visualization functionality to support accident/mishap investigation teams. This accessible, online structure is designed to support investigators by allowing them to make explicit, shared, and meaningful links among evidence, causal models, findings, and recommendations.

  8. TL detectors for gamma ray dose measurements in criticality accidents.

    PubMed

    Miljanić, Saveta; Zorko, Benjamin; Gregori, Beatriz; Knezević, Zeljka

    2007-01-01

    Determination of gamma ray dose in mixed neutron+gamma ray fields is still a demanding task. Dosemeters used for gamma ray dosimetry are usually in some extent sensitive to neutrons and their response variations depend on neutron energy i.e., on neutron spectra. Besides, it is necessary to take into account the energy dependence of dosemeter responses to gamma rays. In this work, several types of thermoluminescent detectors (TLD) placed in different holders used for gamma ray dose determination in the mixed fields were examined. Dosemeters were from three different institutions: Ruder Bosković Institute (RBI), Croatia, JoZef Stefan Institute (JSI), Slovenia and Autoridad Regulatoria Nuclear (ARN), Argentina. All dosemeters were irradiated during the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002. Three accidental scenarios were reproduced and in each irradiation the dosemeters were exposed placed on the front of phantom and 'free in air'. Following types of TLDs were used: 7LiF (TLD-700), CaF2:Mn and Al2O3:Mg,Y-all from RBI; CaF2:Mn from JSI and 7LiF (TLD-700) from ARN. Reported doses were compared with the reference values as well as with the values obtained from the results of all participants. The results show satisfactory agreement with other dosimetry systems used in the Intercomparison. The influence of different types of holders and applied corrections of dosemeters' readings are discussed.

  9. A study of carburetor/induction system icing in general aviation accidents

    NASA Technical Reports Server (NTRS)

    Obermayer, R. W.; Roe, W. T.

    1975-01-01

    An assessment of the frequency and severity of carburetor/induction icing in general-aviation accidents was performed. The available literature and accident data from the National Transportation Safety Board were collected. A computer analysis of the accident data was performed. Between 65 and 90 accidents each year involve carburetor/induction system icing as a probable cause/factor. Under conditions conducive to carburetor/induction icing, between 50 and 70 percent of engine malfunction/failure accidents (exclusive of those due to fuel exhaustion) are due to carburetor/induction system icing. Since the evidence of such icing may not remain long after an accident, it is probable that the frequency of occurrence of such accidents is underestimated; therefore, some extrapolation of the data was conducted. The problem of carburetor/induction system icing is particularly acute for pilots with less than 1000 hours of total flying time. The severity of such accidents is about the same as any accident resulting from a forced landing or precautionary landing. About 144 persons, on the average, are exposed to death and injury each year in accidents involving carburetor/induction icing as a probable cause/factor.

  10. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System

    PubMed Central

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Background: Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. Objectives: The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. Materials and Methods: In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. Results: The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Conclusions: Thus, we can conclude that a simulator system using an extracorporeal

  11. Development of an Accident Reproduction Simulator System Using a Hemodialysis Extracorporeal Circulation System.

    PubMed

    Nishite, Yoshiaki; Takesawa, Shingo

    2016-01-01

    Accidents that occur during dialysis treatment are notified to the medical staff via alarms raised by the dialysis apparatus. Similar to such real accidents, apparatus activation or accidents can be reproduced by simulating a treatment situation. An alarm that corresponds to such accidents can be utilized in the simulation model. The aim of this study was to create an extracorporeal circulation system (hereinafter, the circulation system) for dialysis machines so that it sets off five types of alarms for: 1) decreased arterial pressure, 2) increased arterial pressure, 3) decreased venous pressure, 4) increased venous pressure, and 5) blood leakage, according to the five types of accidents chosen based on their frequency of occurrence and the degree of severity. In order to verify the alarm from the dialysis apparatus connected to the circulation system and the accident corresponding to it, an evaluation of the alarm for its reproducibility of an accident was performed under normal treatment circumstances. The method involved testing whether the dialysis apparatus raised the desired alarm from the moment of control of the circulation system, and measuring the time it took until the desired alarm was activated. This was tested on five main models from four dialyzer manufacturers that are currently used in Japan. The results of the tests demonstrated successful activation of the alarms by the dialysis apparatus, which were appropriate for each of the five types of accidents. The time between the control of the circulatory system to the alarm signal was as follows, 1) venous pressure lower limit alarm: 7 seconds; 2) venous pressure lower limit: 8 seconds; 3) venous pressure upper limit: 7 seconds; 4) venous pressure lower limit alarm: 2 seconds; and 5) blood leakage alarm: 19 seconds. All alarms were set off in under 20 seconds. Thus, we can conclude that a simulator system using an extracorporeal circulation system can be set to different models of dialyzers, and that

  12. 3D dosimetry by optical-CT scanning

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2006-12-01

    The need for an accurate, practical, low-cost 3D dosimetry system is becoming ever more critical as modern dose delivery techniques increase in complexity and sophistication. A recent report from the Radiological Physics Center (RPC) (1), revealed that 38% of institutions failed the head-and-neck IMRT phantom credentialing test at the first attempt. This was despite generous passing criteria (within 7% dose-difference or 4mm distance-to-agreement) evaluated at a half-dozen points and a single axial plane. The question that arises from this disturbing finding is - what percentage of institutions would have failed if a comprehensive 3D measurement had been feasible, rather than measurements restricted to the central film-plane and TLD points? This question can only be adequately answered by a comprehensive 3D-dosimetry system, which presents a compelling argument for its development as a clinically viable low cost dosimetry solution. Optical-CT dosimetry is perhaps the closest system to providing such a comprehensive solution. In this article, we review the origins and recent developments of optical-CT dosimetry systems. The principle focus is on first generation systems known to have highest accuracy but longer scan times.

  13. MO-B-BRB-00: Three Dimensional Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by themore » development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data

  14. Recent Progress in Electromagnetic Absorption and Dosimetry in Biological Systems.

    DTIC Science & Technology

    1978-12-21

    AEROSPACE M!DICAL RESEARCH LABORATORY NAVAL AIR STATION PENSACOLA, FLORIDA 32508 L4 oj6L I SUMMARY PAGE Ti9(PROSLEM Dosimetry , as a subset of research In...absonce of sound dosimetry design, lacks credibility. This study provides a usable orientation in present and future dosimetric technology through a...leading experiment; while at other times experimental results lead the way. Progress In absorption and dosimetry Is still urderway, and higher degrees

  15. LLNL Results from CALIBAN-PROSPERO Nuclear Accident Dosimetry Experiments in September 2014

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lobaugh, M. L.; Hickman, D. P.; Wong, C. W.

    2015-05-21

    Lawrence Livermore National Laboratory (LLNL) uses thin neutron activation foils, sulfur, and threshold energy shielding to determine neutron component doses and the total dose from neutrons in the event of a nuclear criticality accident. The dosimeter also uses a DOELAP accredited Panasonic UD-810 (Panasonic Industrial Devices Sales Company of America, 2 Riverfront Plaza, Newark, NJ 07102, U.S.A.) thermoluminescent dosimetery system (TLD) for determining the gamma component of the total dose. LLNL has participated in three international intercomparisons of nuclear accident dosimeters. In October 2009, LLNL participated in an exercise at the French Commissariat à l’énergie atomique et aux énergies alternativesmore » (Alternative Energies and Atomic Energy Commission- CEA) Research Center at Valduc utilizing the SILENE reactor (Hickman, et.al. 2010). In September 2010, LLNL participated in a second intercomparison at CEA Valduc, this time with exposures at the CALIBAN reactor (Hickman et al. 2011). This paper discusses LLNL’s results of a third intercomparison hosted by the French Institut de Radioprotection et de Sûreté Nucléaire (Institute for Radiation Protection and Nuclear Safety- IRSN) with exposures at two CEA Valduc reactors (CALIBAN and PROSPERO) in September 2014. Comparison results between the three participating facilities is presented elsewhere (Chevallier 2015; Duluc 2015).« less

  16. The use of the dicentric assay for biological dosimetry for radiation accidents in Bulgaria.

    PubMed

    Hadjidekova, Valeria; Hristova, Rositsa; Ainsbury, Elizabeth A; Atanasova, Petya; Popova, Ljubomira; Staynova, Albena

    2010-02-01

    This paper details the construction of a 137Cs gamma calibration curve that has been established for dicentric assay and the testing and validation of the curve through biological dosimetry in three situations of suspected workplace overexposure that arose accidentally or through negligence or lack of appropriate safety measures. The three situations were: (1) suspected 137Cs contamination in a factory air supply; (2) suspected exposure to an industrial 192Ir source; and (3) accidental exposure of construction workers to radiation from a 60Co radiotherapy source in a hospital medical physics department. From a total of 24 potentially-exposed subjects, only one worker was found to have a statistically significant dose (0.16 Gy, 95% confidence intervals 0.02-0.43 Gy). In all other cases, the main function of the biological dosimetry was to reassure the subjects that any dose received was low.

  17. Systemic accident analysis: examining the gap between research and practice.

    PubMed

    Underwood, Peter; Waterson, Patrick

    2013-06-01

    The systems approach is arguably the dominant concept within accident analysis research. Viewing accidents as a result of uncontrolled system interactions, it forms the theoretical basis of various systemic accident analysis (SAA) models and methods. Despite the proposed benefits of SAA, such as an improved description of accident causation, evidence within the scientific literature suggests that these techniques are not being used in practice and that a research-practice gap exists. The aim of this study was to explore the issues stemming from research and practice which could hinder the awareness, adoption and usage of SAA. To achieve this, semi-structured interviews were conducted with 42 safety experts from ten countries and a variety of industries, including rail, aviation and maritime. This study suggests that the research-practice gap should be closed and efforts to bridge the gap should focus on ensuring that systemic methods meet the needs of practitioners and improving the communication of SAA research. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. L Band EPR Tooth Dosimetry for Heavy Ion Irradiation

    PubMed Central

    Yamaguchi, Ichiro; Sato, Hitoshi; Kawamura, Hiraku; Hamano, Tsuyoshi; Yoshii, Hiroshi; Suda, Mitsuru; Miyake, Minoru; Kunugita, Naoki

    2016-01-01

    Electron Paramagnetic Resonance (EPR) tooth dosimetry is being developed as a device to rapidly assess large populations that were potentially exposed to radiation during a major radiation accident or terrorist event. While most exposures are likely to be due to fallout and therefore involve low linear energy transfer (LET) radiation, there is also a potential for exposures to high LET radiation, for which the effect on teeth has been less well characterized by EPR. Therefore, the aim of this paper is to acquire fundamental response curves for high LET radiation in tooth dosimetry using L band EPR. For this purpose, we exposed human teeth to high energy carbon ions using the heavy ion medical accelerator in Chiba at the National Institute of Radiological Sciences. The primary findings were that EPR signals for carbon ion irradiation were about one-tenth the amplitude of the response to the same dose of 150 kVp X-rays. PMID:27542817

  19. The design of Radiation Accident Registry.

    PubMed

    Chen, Jing; Seely, Bob; Bergman, Lauren; Moir, Deborah

    2011-03-01

    In order to provide effective monitoring and follow-up on the health effects of individuals accidentally exposed to ionising radiation, a Radiation Accident Registry (RAR) has been designed and constructed as an extension to the existing National Dose Registry (NDR). The RAR has basic functions of recording, monitoring and reporting. This type of registry is able to assist responders in preparing for and managing situations during radiological events and in providing effective follow-up on the long-term health effects of persons exposed to ionising radiation. It is especially important to register radiation-exposed people in vulnerable population groups, such as children and pregnant women, to ensure proper long-term health care and protection. Even though radiation accidents are rare, a registry prepared for such accidents could involve a large population and, in some cases, require lifetime monitoring for individuals. One of the most challenging tasks associated with RAR is the assessment of radiation dose resulting from accidents. In some cases, the assessment of radiation doses to individuals could be a process requiring the involvement of various methods. The development of fast and accurate dose assessment tools will remain a long-term challenge associated with the RAR. To meet this challenge, further research activities in radiation dosimetry for individual monitoring are needed.

  20. SU-E-T-482: In Vivo Dosimetry of An Anthropomorphic Phantom by Using the RADPOS System for Proton Beam Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kohno, R; Motegi, K; Hotta, K

    Purpose: Delivered doses in an anthropomorphic phantom were evaluated by using the RADPOS system for proton beam therapy. Methods: The RADPOS in vivo dosimetry system combines an electromagnetic positioning sensor with MOSFET dosimetry, allowing simultaneous online measurements of dose and spatial position. Through the RADPOS system, dose evaluation points can be determined. In vivo proton dosimetry was evaluated by using the RADPOS system and anthropomorphic head and neck phantom. MOSFET doses measured at 3D positions obtained with the RADPOS were compared to the treatment plan values that were calculated by a simplified Monte Carlo (SMC) method. Although the MOSFET responsemore » depends strongly on the linear energy transfer (LET) of proton beam, the MOSFET responses to proton beams were corrected with the SMC. Here, the SMC calculated only dose deposition determined by the experimental depth–dose distribution and lateral displacement of protons due to both multiple scattering effect in materials and incident angle. As a Result, the SMC could quickly calculate accurate doses in even heterogeneities. Results: In vivo dosimetry by using the RADPOS, as well as the MOSFET doses agreed in comparison with calculations by the SMC in the range of −3.0% to 8.3%. Most measurement errors occurred because of the uncertainties of dose calculations due to the position error of 1 mm. Conclusion: We evaluated the delivered doses in the anthropomorphic phantom by using the RADPOS system for proton beam therapy. The MOSFET doses agreed in comparison with calculations by the SMC within the measurement error. Therefore, we could successfully control the uncertainties of the measurement positions by using the RADPOS system within 1 mm in in vivo proton dosimetry. We aim for the clinical application of in vivo proton dosimetry with this RADPOS system.« less

  1. Methods for nuclear air-cleaning-system accident-consequence assessment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Andrae, R.W.; Bolstad, J.W.; Gregory, W.S.

    1982-01-01

    This paper describes a multilaboratory research program that is directed toward addressing many questions that analysts face when performing air cleaning accident consequence assessments. The program involves developing analytical tools and supportive experimental data that will be useful in making more realistic assessments of accident source terms within and up to the atmospheric boundaries of nuclear fuel cycle facilities. The types of accidents considered in this study includes fires, explosions, spills, tornadoes, criticalities, and equipment failures. The main focus of the program is developing an accident analysis handbook (AAH). We will describe the contents of the AAH, which include descriptionsmore » of selected nuclear fuel cycle facilities, process unit operations, source-term development, and accident consequence analyses. Three computer codes designed to predict gas and material propagation through facility air cleaning systems are described. These computer codes address accidents involving fires (FIRAC), explosions (EXPAC), and tornadoes (TORAC). The handbook relies on many illustrative examples to show the analyst how to approach accident consequence assessments. We will use the FIRAC code and a hypothetical fire scenario to illustrate the accident analysis capability.« less

  2. WE-AB-BRB-12: Nanoscintillator Fiber-Optic Detector System for Microbeam Radiation Therapy Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rivera, J; Dooley, J; Chang, S

    2015-06-15

    Purpose: Microbeam Radiation Therapy (MRT) is an experimental radiation therapy that has demonstrated a higher therapeutic ratio than conventional radiation therapy in animal studies. There are several roadblocks in translating the promising treatment technology to clinical application, one of which is the lack of a real-time, high-resolution dosimeter. Current clinical radiation detectors have poor spatial resolution and, as such, are unsuitable for measuring microbeams with submillimeter-scale widths. Although GafChromic film has high spatial resolution, it lacks the real-time dosimetry capability necessary for MRT preclinical research and potential clinical use. In this work we have demonstrated the feasibility of using amore » nanoscintillator fiber-optic detector (nanoFOD) system for real-time MRT dosimetry. Methods: A microplanar beam array is generated using a x-ray research irradiator and a custom-made, microbeam-forming collimator. The newest generation nanoFOD has an effective size of 70 µm in the measurement direction and was calibrated against a kV ion chamber (RadCal Accu-Pro) in open field geometry. We have written a computer script that performs automatic data collection with immediate background subtraction. A computer-controlled detector positioning stage is used to precisely measure the microbeam peak dose and beam profile by translating the stage during data collection. We test the new generation nanoFOD system, with increased active scintillation volume, against the previous generation system. Both raw and processed data are time-stamped and recorded to enable future post-processing. Results: The real-time microbeam dosimetry system worked as expected. The new generation dosimeter has approximately double the active volume compared to the previous generation resulting in over 900% increase in signal. The active volume of the dosimeter still provided the spatial resolution that meets the Nyquist criterion for our microbeam widths. Conclusion

  3. Future Integrated Systems Concept for Preventing Aircraft Loss-of-Control Accidents

    NASA Technical Reports Server (NTRS)

    Belcastro, Christine M.; Jacobson, Steven r.

    2010-01-01

    Loss of control remains one of the largest contributors to aircraft fatal accidents worldwide. Aircraft loss-of-control accidents are highly complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. Hence, there is no single intervention strategy to prevent these accidents. This paper presents future system concepts and research directions for preventing aircraft loss-of-control accidents.

  4. TLD and OSLD dosimetry systems for remote audits of radiotherapy external beam calibration.

    PubMed

    Alvarez, P; Kry, S F; Stingo, F; Followill, D

    2017-11-01

    The Imaging and Radiation Oncology Core QA Center in Houston (IROC-H) performs remote dosimetry audits of more than 20,000 megavoltage photon and electron beams each year. Both a thermoluminescent dosimeter (TLD-100) and optically stimulated luminescent dosimeter (OSLD; nanoDot) system are commissioned for this task, with the OSLD system being predominant due to the more time-efficient read-out process. The measurement apparatus includes 3 TLD or 2 OSLD in an acrylic mini-phantom, which are irradiated by the institution under reference geometry. Dosimetry systems are calibrated based on the signal-to-dose conversion established with reference dosimeters irradiated in a Co-60 beam, using a reference dose of 300 cGy for TLD and 100 cGy for OSLD. The uncertainty in the dose determination is 1.3% for TLD and 1.6% for OSLD at the one sigma level. This accuracy allows for a tolerance of ±5% to be used.

  5. Personnel neutron dosimetry using electrochemically etched CR-39 foils

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hankins, D.E.; Homann, S.; Westermark, J.

    1986-09-17

    A personnel neutron dosimetry system has been developed based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This Cr-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. The dosimetry system employs an electrochemical etch procedure that be used to process large numbers of Cr-39 dosimeters. The etch procedure is suitable for operations where the number of personnelmore » requires that many CR-39 dosimeters be processed. Experience shows that one full-time technician can etch and evaluate 2000 foils per month. The energy response to neutrons is fairly flat from about 80 keV to 3.5 MeV, but drops by about a factor of three in the 13 to 16 MeV range. The sensitivity of the dosimetry system is about 7 tracks/cm/sup 2//mrem, with a background equivalent to about 8 mrem for new CR-39 foils. The limit of sensitivity is approximately 10 mrem. The dosimeter has a significant variation in directional dependence, dropping to about 20% at 90/sup 0/. This dosimeter has been used for personnel neutron dosimetry at the Lawrence Livermore National Laboratory for more tha 18 months. 6 refs., 23 figs., 2 tabs.« less

  6. Evaluation of severe accident risks: Quantification of major input parameters: MAACS (MELCOR Accident Consequence Code System) input

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sprung, J.L.; Jow, H-N; Rollstin, J.A.

    1990-12-01

    Estimation of offsite accident consequences is the customary final step in a probabilistic assessment of the risks of severe nuclear reactor accidents. Recently, the Nuclear Regulatory Commission reassessed the risks of severe accidents at five US power reactors (NUREG-1150). Offsite accident consequences for NUREG-1150 source terms were estimated using the MELCOR Accident Consequence Code System (MACCS). Before these calculations were performed, most MACCS input parameters were reviewed, and for each parameter reviewed, a best-estimate value was recommended. This report presents the results of these reviews. Specifically, recommended values and the basis for their selection are presented for MACCS atmospheric andmore » biospheric transport, emergency response, food pathway, and economic input parameters. Dose conversion factors and health effect parameters are not reviewed in this report. 134 refs., 15 figs., 110 tabs.« less

  7. Evaluation of Dosimetry Check software for IMRT patient-specific quality assurance.

    PubMed

    Narayanasamy, Ganesh; Zalman, Travis; Ha, Chul S; Papanikolaou, Niko; Stathakis, Sotirios

    2015-05-08

    The purpose of this study is to evaluate the use of the Dosimetry Check system for patient-specific IMRT QA. Typical QA methods measure the dose in an array dosimeter surrounded by homogenous medium for which the treatment plan has been recomputed. With the Dosimetry Check system, fluence measurements acquired on a portal dosimeter is applied to the patient's CT scans. Instead of making dose comparisons in a plane, Dosimetry Check system produces isodose lines and dose-volume histograms based on the planning CT images. By exporting the dose distribution from the treatment planning system into the Dosimetry Check system, one is able to make a direct comparison between the calculated dose and the planned dose. The versatility of the software is evaluated with respect to the two IMRT techniques - step and shoot and volumetric arc therapy. The system analyzed measurements made using EPID, PTW seven29, and IBA MatriXX, and an intercomparison study was performed. Plans from patients previously treated at our institution with treated anatomical site on brain, head & neck, liver, lung, and prostate were analyzed using Dosimetry Check system for any anatomical site dependence. We have recommendations and possible precautions that may be necessary to ensure proper QA with the Dosimetry Check system.

  8. Development of water environment information management and water pollution accident response system

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Ruan, H.

    2009-12-01

    In recent years, many water pollution accidents occurred with the rapid economical development. In this study, water environment information management and water pollution accident response system are developed based on geographic information system (GIS) techniques. The system integrated spatial database, attribute database, hydraulic model, and water quality model under a user-friendly interface in a GIS environment. System ran in both Client/Server (C/S) and Browser/Server (B/S) platform which focused on model and inquiry respectively. System provided spatial and attribute data inquiry, water quality evaluation, statics, water pollution accident response case management (opening reservoir etc) and 2D and 3D visualization function, and gave assistant information to make decision on water pollution accident response. Polluted plume in Huaihe River were selected to simulate the transport of pollutes.

  9. [Violence and accidents among older and younger adults: evidence from the Surveillance System for Violence and Accidents (VIVA), Brazil].

    PubMed

    Luz, Tatiana Chama Borges; Malta, Deborah Carvalho; Sá, Naíza Nayla Bandeira de; Silva, Marta Maria Alves da; Lima-Costa, Maria Fernanda

    2011-11-01

    Data from the Brazilian Surveillance System for Violence and Accidents (VIVA) in 2009 were used to examine socio-demographic characteristics, outcomes, and types of accidents and violence treated at 74 sentinel emergency services in 23 Brazilian State capitals and the Federal District. The analysis included 25,201 individuals aged > 20 years (10.1% > 60 years); 89.3% were victims of accidents and 11.9% victims of violence. Hospitalization was the outcome in 11.1% of cases. Compared to the general population, there were more men and non-white individuals among victims of accidents, and especially among victims of violence. As compared to younger adults (20-59 years), accidents and violence against elderly victims showed less association with alcohol, a higher proportion of domestic incidents, more falls and pedestrian accidents, and aggression by family members. Policies for the prevention of accidents and violence should consider the characteristics of these events in the older population.

  10. 78 FR 6732 - Changes to Standard Numbering System, Vessel Identification System, and Boating Accident Report...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... Boating Accident Report Database AGENCY: Coast Guard, DHS. ACTION: Rule; information collection approval... Identification System, and Boating Accident Report Database rule became effective on April 27, 2012. Under the...

  11. The Mayak Worker Dosimetry System (MWDS-2013): Implementation of the Dose Calculations.

    PubMed

    Zhdanov, А; Vostrotin, V; Efimov, А; Birchall, A; Puncher, M

    2016-07-15

    The calculation of internal doses for the Mayak Worker Dosimetry System (MWDS-2013) involved extensive computational resources due to the complexity and sheer number of calculations required. The required output consisted of a set of 1000 hyper-realizations: each hyper-realization consists of a set (1 for each worker) of probability distributions of organ doses. This report describes the hardware components and computational approaches required to make the calculation tractable. Together with the software, this system is referred to here as the 'PANDORA system'. It is based on a commercial SQL server database in a series of six work stations. A complete run of the entire Mayak worker cohort entailed a huge amount of calculations in PANDORA and due to the relatively slow speed of writing the data into the SQL server, each run took about 47 days. Quality control was monitored by comparing doses calculated in PANDORA with those in a specially modified version of the commercial software 'IMBA Professional Plus'. Suggestions are also made for increasing calculation and storage efficiency for future dosimetry calculations using PANDORA. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Nonuniform Irradiation of the Canine Intestine. 2. Dosimetry

    DTIC Science & Technology

    1990-01-01

    irradiation is accurate assessment In vivo dosimetry was done using Harshaw (Solon, Ohio) TLD - 100 lith- of the injury after either accidental or... vivo TLD dosimetry system allowed measure- 5 and 6. The dose was determined from the median TLD ment of the °Co dose deposited in the canine small...provide replicate measurements. Two separate dosimetry tubes were deveoped (Fig. 1). The first contained 30 TLD cap- doses (1). Nevertheless, current

  13. Quality management system in the CIEMAT Radiation Dosimetry Service.

    PubMed

    Martín, R; Navarro, T; Romero, A M; López, M A

    2011-03-01

    This paper describes the activities realised by the CIEMAT Radiation Dosimetry Service (SDR) for the implementation of a quality management system (QMS) in order to achieve compliance with the requirements of ISO/IEC 17025 and to apply for the accreditation for testing measurements of radiation dose. SDR has decided the accreditation of the service as a whole and not for each of its component laboratories. This makes it necessary to design a QMS common to all, thus ensuring alignment and compliance with standard requirements, and simplifying routine works as possible.

  14. TU-F-201-00: Radiochromic Film Dosimetry Update

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to)more » external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.« less

  15. ADAM: An Accident Diagnostic,Analysis and Management System - Applications to Severe Accident Simulation and Management

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zavisca, M.J.; Khatib-Rahbar, M.; Esmaili, H.

    2002-07-01

    The Accident Diagnostic, Analysis and Management (ADAM) computer code has been developed as a tool for on-line applications to accident diagnostics, simulation, management and training. ADAM's severe accident simulation capabilities incorporate a balance of mechanistic, phenomenologically based models with simple parametric approaches for elements including (but not limited to) thermal hydraulics; heat transfer; fuel heatup, meltdown, and relocation; fission product release and transport; combustible gas generation and combustion; and core-concrete interaction. The overall model is defined by a relatively coarse spatial nodalization of the reactor coolant and containment systems and is advanced explicitly in time. The result is to enablemore » much faster than real time (i.e., 100 to 1000 times faster than real time on a personal computer) applications to on-line investigations and/or accident management training. Other features of the simulation module include provision for activation of water injection, including the Engineered Safety Features, as well as other mechanisms for the assessment of accident management and recovery strategies and the evaluation of PSA success criteria. The accident diagnostics module of ADAM uses on-line access to selected plant parameters (as measured by plant sensors) to compute the thermodynamic state of the plant, and to predict various margins to safety (e.g., times to pressure vessel saturation and steam generator dryout). Rule-based logic is employed to classify the measured data as belonging to one of a number of likely scenarios based on symptoms, and a number of 'alarms' are generated to signal the state of the reactor and containment. This paper will address the features and limitations of ADAM with particular focus on accident simulation and management. (authors)« less

  16. Cirrus Airframe Parachute System and Odds of a Fatal Accident in Cirrus Aircraft Crashes.

    PubMed

    Alaziz, Mustafa; Stolfi, Adrienne; Olson, Dean M

    2017-06-01

    General aviation (GA) accidents have continued to demonstrate high fatality rates. Recently, ballistic parachute recovery systems (BPRS) have been introduced as a safety feature in some GA aircraft. This study evaluates the effectiveness and associated factors of the Cirrus Airframe Parachute System (CAPS) at reducing the odds of a fatal accident in Cirrus aircraft crashes. Publicly available Cirrus aircraft crash reports were obtained from the National Transportation Safety Board (NTSB) database for the period of January 1, 2001-December 31, 2016. Accident metrics were evaluated through univariate and multivariate analyses regarding odds of a fatal accident and use of the parachute system. Included in the study were 268 accidents. For CAPS nondeployed accidents, 82 of 211 (38.9%) were fatal as compared to 8 of 57 (14.0%) for CAPS deployed accidents. After controlling for all other factors, the adjusted odds ratio for a fatal accident when CAPS was not deployed was 13.1. The substantial increased odds of a fatal accident when CAPS was not deployed demonstrated the effectiveness of CAPS at providing protection of occupants during an accident. Injuries were shifted from fatal to serious or minor with the use of CAPS and postcrash fires were significantly reduced. These results suggest that BPRS could play a significant role in the next major advance in improving GA accident survival.Alaziz M, Stolfi A, Olson DM. Cirrus Airframe Parachute System and odds of a fatal accident in Cirrus aircraft crashes. Aerosp Med Hum Perform. 2017; 88(6):556-564.

  17. Characterizing a pulse-resolved dosimetry system for complex radiotherapy beams using organic scintillators.

    PubMed

    Beierholm, Anders R; Ottosson, Rickard O; Lindvold, Lars R; Behrens, Claus F; Andersen, Claus E

    2011-05-21

    A fast-readout dosimetry system based on fibre-coupled organic scintillators has been developed for the purpose of conducting point measurements of absorbed dose in radiotherapy beams involving high spatial and temporal dose gradients. The system measures the dose for each linac radiation pulse with millimetre spatial resolution. To demonstrate the applicability of the system in complex radiotherapy fields, output factors and per cent depth dose measurements were performed in solid water for a 6 MV photon beam and compared with Monte Carlo simulated doses for square fields down to 0.6 cm × 0.6 cm size. No significant differences between measurements and simulations were observed. The temporal resolution of the system was demonstrated by measuring dose per pulse, beam start-up transients and the quality factor for 6 MV. The precision of dose per pulse measurements was within 2.7% (1 SD) for a 10 cm × 10 cm field at 10 cm depth. The dose per pulse behaviour compared well with linac target current measurements and accumulated dose measurements, and the system was able to resolve transient dose delivery differences between two Varian linac builds. The system therefore shows promise for reference dosimetry and quality assurance of complex radiotherapy treatments.

  18. Evaluation and improvement of the inquest system on work accidents (TOT)

    NASA Astrophysics Data System (ADS)

    Lepistoe, Jukka

    1992-11-01

    A project to evaluate and improve the work accident inquest system TOT (Finnish acronym) is reported. The study began with visits to workplaces where mortal accidents had occurred. Inquest reports, accident information dissemination, and the use of inquest reports, were examined. The study showed that work-related accidental deaths had a warning value, due to the gravity of the event, that could be exploited in the prevention field. The inquest system was shown to operate stably, all elements operating at least satisfactorily, and no improvement objective could be distinguished as more urgent than another. Improvement possibilities in the general system operation and in the capacity of workplaces to use inquest reports were shown.

  19. Medical management of radiation accidents: capabilities and deployment principles of the Bundeswehr Institute of Radiobiology.

    PubMed

    Dörr, Harald; Meineke, Viktor

    2012-10-01

    Radiation accidents are fortunately infrequent occurrences, but since their consequences can be very serious as in the Chernobyl and the Fukushima nuclear accidents, medical management of radiation accidents is of great importance. Besides several other tasks, medical management of radiation accidents is one of the key tasks of the Bundeswehr Institute of Radiobiology. Within a Task Force Unit for medical chemical, biological, radiological, and nuclear (CBRN) Defense, the institute provides designated personnel who will perform clinical investigations on the scene and will liaise with the institute, where different methods for biological dosimetry and dose reconstruction will be performed. The most important aspects of efficient medical management of radiation accidents are diagnosis of radiation-induced health damage, determination of the cause, dealing with contamination/incorporation, pathophysiological and therapeutic principles, preparatory planning, national and international cooperation and training. Military and non-military institutions have to work closely together when it comes to radiation accidents and since national resources are limited and could be exhausted, international networks can help to ensure medical treatment for radiation accident victims.

  20. Computer Aided Dosimetry and Verification of Exposure to Radiation

    DTIC Science & Technology

    2002-06-01

    Event matrix 2. Hematopoietic * Absolute blood counts * Relative blood counts 3. Dosimetry * TLD * EPDQuantitative * Radiation survey * Whole body...EI1 Defence Research and Recherche et developpement Development Canada pour la d6fense Canada DEFENCE •mI•DEFENSE Computer Aided Dosimetry and...Aided Dosimetry and Verification of Exposure to Radiation Edward Waller SAIC Canada Robert Z Stodilka Radiation Effects Group, Space Systems and

  1. Recent developments of optically stimulated luminescence materials and techniques for radiation dosimetry and clinical applications.

    PubMed

    Pradhan, A S; Lee, J I; Kim, J L

    2008-07-01

    During the last 10 years, optically stimulated luminescence (OSL) has emerged as a formidable competitor not only to thermoluminescence dosimetry (TLD) but also to several other dosimetry systems. Though a large number of materials have been synthesized and studied for OSL, Al(2)O(3):C continues to dominate the dosimetric applications. Re-investigations of OSL in BeOindicate that this material might provide an alternative to Al(2)O(3):C. Study of OSL of electronic components of mobile phones and ID cards appears to have opened up a feasibility of dosimetry and dose reconstruction using the electronic components of gadgets of everyday use in the events of unforeseen situations of radiological accidents, including the event of a dirty bomb by terrorist groups. Among the newly reported materials, a very recent development of NaMgF(3):Eu(2+) appears fascinating because of its high OSL sensitivity and tolerable tissue equivalence. In clinical dosimetry, an OSL as a passive dosimeter could do all that TLD can do, much faster with a better or at least the same efficiency; and in addition, it provides a possibility of repeated readout unlike TLD, in which all the dose information is lost in a single readout. Of late, OSL has also emerged as a practical real-time dosimeter for in vivo measurements in radiation therapy (for both external beams and brachytherapy) and in various diagnostic radiological examinations including mammography and CT dosimetry. For in vivo measurements, a probe of Al(2)O(3):C of size of a fraction of a millimeter provides the information on both the dose rate and the total dose from the readout of radioluminescence and OSL signals respectively, from the same probe. The availability of OSL dosimeters in various sizes and shapes and their performance characteristics as compared to established dosimeters such as plastic scintillation dosimeters, diode detectors, MOSFET detectors, radiochromic films, etc., shows that OSL may soon become the first choice

  2. Recent developments of optically stimulated luminescence materials and techniques for radiation dosimetry and clinical applications

    PubMed Central

    Pradhan, A. S.; Lee, J. I.; Kim, J. L.

    2008-01-01

    During the last 10 years, optically stimulated luminescence (OSL) has emerged as a formidable competitor not only to thermoluminescence dosimetry (TLD) but also to several other dosimetry systems. Though a large number of materials have been synthesized and studied for OSL, Al2O3:C continues to dominate the dosimetric applications. Re-investigations of OSL in BeOindicate that this material might provide an alternative to Al2O3:C. Study of OSL of electronic components of mobile phones and ID cards appears to have opened up a feasibility of dosimetry and dose reconstruction using the electronic components of gadgets of everyday use in the events of unforeseen situations of radiological accidents, including the event of a dirty bomb by terrorist groups. Among the newly reported materials, a very recent development of NaMgF3:Eu2+ appears fascinating because of its high OSL sensitivity and tolerable tissue equivalence. In clinical dosimetry, an OSL as a passive dosimeter could do all that TLD can do, much faster with a better or at least the same efficiency; and in addition, it provides a possibility of repeated readout unlike TLD, in which all the dose information is lost in a single readout. Of late, OSL has also emerged as a practical real-time dosimeter for in vivo measurements in radiation therapy (for both external beams and brachytherapy) and in various diagnostic radiological examinations including mammography and CT dosimetry. For in vivo measurements, a probe of Al2O3:C of size of a fraction of a millimeter provides the information on both the dose rate and the total dose from the readout of radioluminescence and OSL signals respectively, from the same probe. The availability of OSL dosimeters in various sizes and shapes and their performance characteristics as compared to established dosimeters such as plastic scintillation dosimeters, diode detectors, MOSFET detectors, radiochromic films, etc., shows that OSL may soon become the first choice for point dose

  3. Recommendations to harmonize European early warning dosimetry network systems

    NASA Astrophysics Data System (ADS)

    Dombrowski, H.; Bleher, M.; De Cort, M.; Dabrowski, R.; Neumaier, S.; Stöhlker, U.

    2017-12-01

    After the Chernobyl nuclear power plant accident in 1986, followed by the Fukushima Nuclear power plant accident 25 years later, it became obvious that real-time information is required to quickly gain radiological information. As a consequence, the European countries established early warning network systems with the aim to provide an immediate warning in case of a major radiological emergency, to supply reliable information on area dose rates, contamination levels, radioactivity concentrations in air and finally to assess public exposure. This is relevant for governmental decisions on intervention measures in an emergency situation. Since different methods are used by national environmental monitoring systems to measure area dose rate values and activity concentrations, there are significant differences in the results provided by different countries. Because European and neighboring countries report area dose rate data to a central data base operated on behalf of the European Commission, the comparability of the data is crucial for its meaningful interpretation, especially in the case of a nuclear accident with transboundary implications. Only by harmonizing measuring methods and data evaluation, is the comparability of the dose rate data ensured. This publication concentrates on technical requirements and methods with the goal to effectively harmonize area dose rate monitoring data provided by automatic early warning network systems. The requirements and procedures laid down in this publication are based on studies within the MetroERM project, taking into account realistic technical approaches and tested procedures.

  4. PREFACE: Third International Conference on Radiotherapy Gel Dosimetry

    NASA Astrophysics Data System (ADS)

    DeDeene, Yves; Baldock, Clive

    2004-01-01

    Gel dosimetry is not merely another dosimetry technique. Gel dosimeters are integrating dosimeters that enable dose verification in three dimensions. The application of a 3D dosimetry technique in the clinic would give a real push to the implementation of advanced high-precision radiotherapy technologies in many institutes. It can be expected that with the recent developments in the field towards more user-friendly gel systems and imaging modalities, gel dosimetry will become a vital link in the chain of high-precision radiation cancer therapy in the near future. Many researchers all over the world have contributed to the emerging technology of gel dosimetry. The research field of gel dosimetry is recognized to be very broad from polymer and analytical chemistry and material research to imaging technologies. The DOSGEL conferences in the past have proven to be an important forum at which material scientists, chemists, medical physicists, magnetic resonance imaging and radiation specialists brought together a critical mass of thoughts, findings and considerations. DOSGEL 2004 has been endorsed by many international, supra-national and national medical physics organizations and publishers. These proceedings contain 51 papers that cover various aspects of gel dosimetry.

  5. Monte Carlo simulations in radiotherapy dosimetry.

    PubMed

    Andreo, Pedro

    2018-06-27

    The use of the Monte Carlo (MC) method in radiotherapy dosimetry has increased almost exponentially in the last decades. Its widespread use in the field has converted this computer simulation technique in a common tool for reference and treatment planning dosimetry calculations. This work reviews the different MC calculations made on dosimetric quantities, like stopping-power ratios and perturbation correction factors required for reference ionization chamber dosimetry, as well as the fully realistic MC simulations currently available on clinical accelerators, detectors and patient treatment planning. Issues are raised that include the necessity for consistency in the data throughout the entire dosimetry chain in reference dosimetry, and how Bragg-Gray theory breaks down for small photon fields. Both aspects are less critical for MC treatment planning applications, but there are important constraints like tissue characterization and its patient-to-patient variability, which together with the conversion between dose-to-water and dose-to-tissue, are analysed in detail. Although these constraints are common to all methods and algorithms used in different types of treatment planning systems, they make uncertainties involved in MC treatment planning to still remain "uncertain".

  6. Implementation of a real-time intersection accident detection system (Phase 1).

    DOT National Transportation Integrated Search

    2004-10-01

    The focus of this research is the feasibility study for the implementation of a real-time accident : detection system at intersections. After reviewing accident detection algorithms investigated in the prior : phase of the research, we explored schem...

  7. Accidental neutron dosimetry with human hair

    NASA Astrophysics Data System (ADS)

    Ekendahl, Daniela; Bečková, Věra; Zdychová, Vlasta; Bulánek, Boris; Prouza, Zdeněk; Štefánik, Milan

    2014-11-01

    Human hair contains sulfur, which can be activated by fast neutrons. The 32S(n,p)32P reaction with a threshold of 2.5 MeV was used for fast neutron dose estimation. It is a very important parameter for individual dose reconstruction with regards to the heterogeneity of the neutron transfer to the human body. Samples of human hair were irradiated in a radial channel of a training reactor VR-1. 32P activity in hair was measured both, directly by means of a proportional counter, and as ash dispersed in a liquid scintillator. Based on neutron spectrum estimation, a relationship between the neutron dose and induced activity was derived. The experiment verified the practical feasibility of this dosimetry method in cases of criticality accidents or malevolent acts with nuclear materials.

  8. Commissioning dosimetry and in situ dose mapping of a semi-industrial Cobalt-60 gamma-irradiation facility using Fricke and Ceric-cerous dosimetry system and comparison with Monte Carlo simulation data

    NASA Astrophysics Data System (ADS)

    Mortuza, Md Firoz; Lepore, Luigi; Khedkar, Kalpana; Thangam, Saravanan; Nahar, Arifatun; Jamil, Hossen Mohammad; Bandi, Laxminarayan; Alam, Md Khorshed

    2018-03-01

    Characterization of a 90 kCi (3330 TBq), semi-industrial, cobalt-60 gamma irradiator was performed by commissioning dosimetry and in-situ dose mapping experiments with Ceric-cerous and Fricke dosimetry systems. Commissioning dosimetry was carried out to determine dose distribution pattern of absorbed dose in the irradiation cell and products. To determine maximum and minimum absorbed dose, overdose ratio and dwell time of the tote boxes, homogeneous dummy product (rice husk) with a bulk density of 0.13 g/cm3 were used in the box positions of irradiation chamber. The regions of minimum absorbed dose of the tote boxes were observed in the lower zones of middle plane and maximum absorbed doses were found in the middle position of front plane. Moreover, as a part of dose mapping, dose rates in the wall positions and some selective strategic positions were also measured to carry out multiple irradiation program simultaneously, especially for low dose research irradiation program. In most of the cases, Monte Carlo simulation data, using Monte Carlo N-Particle eXtended code version MCNPX 2.7., were found to be in congruence with experimental values obtained from Ceric-cerous and Fricke dosimetry; however, in close proximity positions from the source, the dose rate variation between chemical dosimetry and MCNP was higher than distant positions.

  9. Technical considerations for implementation of x-ray CT polymer gel dosimetry.

    PubMed

    Hilts, M; Jirasek, A; Duzenli, C

    2005-04-21

    Gel dosimetry is the most promising 3D dosimetry technique in current radiation therapy practice. X-ray CT has been shown to be a feasible method of reading out polymer gel dosimeters and, with the high accessibility of CT scanners to cancer hospitals, presents an exciting possibility for clinical implementation of gel dosimetry. In this study we report on technical considerations for implementation of x-ray CT polymer gel dosimetry. Specifically phantom design, CT imaging methods, imaging time requirements and gel dose response are investigated. Where possible, recommendations are made for optimizing parameters to enhance system performance. The dose resolution achievable with an optimized system is calculated given voxel size and imaging time constraints. Results are compared with MRI and optical CT polymer gel dosimetry results available in the literature.

  10. A quantification of the effectiveness of EPID dosimetry and software-based plan verification systems in detecting incidents in radiotherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bojechko, Casey; Phillps, Mark; Kalet, Alan

    Purpose: Complex treatments in radiation therapy require robust verification in order to prevent errors that can adversely affect the patient. For this purpose, the authors estimate the effectiveness of detecting errors with a “defense in depth” system composed of electronic portal imaging device (EPID) based dosimetry and a software-based system composed of rules-based and Bayesian network verifications. Methods: The authors analyzed incidents with a high potential severity score, scored as a 3 or 4 on a 4 point scale, recorded in an in-house voluntary incident reporting system, collected from February 2012 to August 2014. The incidents were categorized into differentmore » failure modes. The detectability, defined as the number of incidents that are detectable divided total number of incidents, was calculated for each failure mode. Results: In total, 343 incidents were used in this study. Of the incidents 67% were related to photon external beam therapy (EBRT). The majority of the EBRT incidents were related to patient positioning and only a small number of these could be detected by EPID dosimetry when performed prior to treatment (6%). A large fraction could be detected by in vivo dosimetry performed during the first fraction (74%). Rules-based and Bayesian network verifications were found to be complimentary to EPID dosimetry, able to detect errors related to patient prescriptions and documentation, and errors unrelated to photon EBRT. Combining all of the verification steps together, 91% of all EBRT incidents could be detected. Conclusions: This study shows that the defense in depth system is potentially able to detect a large majority of incidents. The most effective EPID-based dosimetry verification is in vivo measurements during the first fraction and is complemented by rules-based and Bayesian network plan checking.« less

  11. Innovation and the future of advanced dosimetry: 2D to 5D

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2017-05-01

    Recent years have witnessed a remarkable evolution in the techniques, capabilities and applications of 3D dosimetry. Initially the goal was simple: to innovate new techniques capable of comprehensively measuring and verifying exquisitely intricate dose distributions from a paradigm changing emerging new therapy, IMRT. Basic questions emerged: how well were treatment planning systems modelling the complex delivery, and how could treatments be verified for safe use on patients? Since that time, equally significant leaps of innovation have continued in the technology of treatment delivery. In addition, clinical practice has been transformed by the addition of on-board imaging capabilities, which tend to hypo-fractionation strategies and margin reduction. The net result is a high stakes treatment setting where the clinical morbidity of any unintended treatment deviation is exacerbated by the combination of highly conformal dose distributions given with reduced margins with fractionation regimens unfriendly to healthy tissue. Not surprisingly this scenario is replete with challenges and opportunities for new and improved dosimetry systems. In particular tremendous interest exists in comprehensive 3D dosimetry systems, and systems that can resolve the dose in moving structures (4D) and even in deforming structures (5D). Despite significant progress in the capability of multi-dimensional dosimetry systems, it is striking that true 3D dosimetry systems are today largely found in academic institutions or specialist clinics. The reasons will be explored. We will highlight innovations occurring both in treatment delivery and in advanced dosimetry methods designed to verify them, and explore current and future opportunities for advanced dosimetry tools in clinical practice and translational research.

  12. Multi-phase model development to assess RCIC system capabilities under severe accident conditions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kirkland, Karen Vierow; Ross, Kyle; Beeny, Bradley

    The Reactor Core Isolation Cooling (RCIC) System is a safety-related system that provides makeup water for core cooling of some Boiling Water Reactors (BWRs) with a Mark I containment. The RCIC System consists of a steam-driven Terry turbine that powers a centrifugal, multi-stage pump for providing water to the reactor pressure vessel. The Fukushima Dai-ichi accidents demonstrated that the RCIC System can play an important role under accident conditions in removing core decay heat. The unexpectedly sustained, good performance of the RCIC System in the Fukushima reactor demonstrates, firstly, that its capabilities are not well understood, and secondly, that themore » system has high potential for extended core cooling in accident scenarios. Better understanding and analysis tools would allow for more options to cope with a severe accident situation and to reduce the consequences. The objectives of this project were to develop physics-based models of the RCIC System, incorporate them into a multi-phase code and validate the models. This Final Technical Report details the progress throughout the project duration and the accomplishments.« less

  13. Factors correlated with traffic accidents as a basis for evaluating Advanced Driver Assistance Systems.

    PubMed

    Staubach, Maria

    2009-09-01

    This study aims to identify factors which influence and cause errors in traffic accidents and to use these as a basis for information to guide the application and design of driver assistance systems. A total of 474 accidents were examined in depth for this study by means of a psychological survey, data from accident reports, and technical reconstruction information. An error analysis was subsequently carried out, taking into account the driver, environment, and vehicle sub-systems. Results showed that all accidents were influenced by errors as a consequence of distraction and reduced activity. For crossroad accidents, there were further errors resulting from sight obstruction, masked stimuli, focus errors, and law infringements. Lane departure crashes were additionally caused by errors as a result of masked stimuli, law infringements, expectation errors as well as objective and action slips, while same direction accidents occurred additionally because of focus errors, expectation errors, and objective and action slips. Most accidents were influenced by multiple factors. There is a safety potential for Advanced Driver Assistance Systems (ADAS), which support the driver in information assimilation and help to avoid distraction and reduced activity. The design of the ADAS is dependent on the specific influencing factors of the accident type.

  14. Section 9.1 new dosimeters. New dosimetry systems

    NASA Astrophysics Data System (ADS)

    McLaughlin, William L.

    During the past two years there have been significant advances in several forms of radiation measurement systems for radiation processing, covering dose ranges of 1-10 6 Gy. Calorimeters as reference standards for both ionizing photon and electron fields have become well-established. In addition to the older ceric-cerous dosimetry solution analyzed potentiometrically, new liquid-phase dosimeters include those analyzed by spectrophotometry, e.g., improved forms of acidic aqueous solutions of K-Ag dichromate and organic radiochromic dye solutions. It has recently been demonstrated that by using certain refined sugars, e.g., D-(-) ribose, optical rotation response in aqueous solutions can be enhanced for dosimetry at doses > 10 4 Gy. There has been expanded development, use, and formulation (rods, tablets, and thin films) of the amino acid, alanine, as a solid-phase dosimeter analyzed by either ESR spectrometry or by glutamine or alanine spectrophotometry of complexes with ferric ion in the presence of a sulfonphthalein dye (xylenol orange). New commercial types of radiochromic plastic dosimeters, e.g., GafChromic TM, Riso B3 TM, GAMMACHROME YR TM, Radix TM, and Gammex TM, have been introduced and applied in practice. Improvements and broader use of optical waveguide dosimeters, e.g., Opti-Chromic TM, have also been reported, especially in food irradiation applications. Several novel dyed plastic dosimeters are available in large quantities and they lose color due to irradiation. An example is a dyed cellulosic thin film (ATC type DY-42 TM) which can be measured spectrophotometrically or densitometrically up to doses as high as 10 6 Gy.

  15. A comprehensive evaluation of the PRESAGE/optical-CT 3D dosimetry system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sakhalkar, H. S.; Adamovics, J.; Ibbott, G.

    2009-01-15

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H and N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1x3 cm{sup 2}) impinging on the flat circular face of the dosimeter. A repetitiousmore » sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to {approx}2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight

  16. Building of communication system for nuclear accident emergency disposal based on IP multimedia subsystem

    NASA Astrophysics Data System (ADS)

    Wang, Kang; Gao, Guiqing; Qin, Yuanli; He, Xiangyong

    2018-05-01

    The nuclear accident emergency disposal must be supported by an efficient, real-time modularization and standardization communication system. Based on the analysis of communication system for nuclear accident emergency disposal which included many functions such as the internal and external communication, multiply access supporting and command center. Some difficult problems of the communication system were discussed such as variety access device type, complex composition, high mobility, set up quickly, multiply business support, and so on. Taking full advantages of the IP Multimedia Subsystem (IMS), a nuclear accident emergency communication system was build based on the IMS. It was studied and implemented that some key unit and module functions of communication system were included the system framework implementation, satellite access, short-wave access, load/vehicle-mounted communication units. The application tests showed that the system could provide effective communication support for the nuclear accident emergency disposal, which was of great practical value.

  17. Poster – 13: Evaluation of an in-house CCD camera film dosimetry imaging system for small field deliveries

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lalonde, Michel; Alexander, Kevin; Olding, Tim

    Purpose: Radiochromic film dosimetry is a standard technique used in clinics to verify modern conformal radiation therapy delivery, and sometimes in research to validate other dosimeters. We are using film as a standard for comparison as we improve high-resolution three-dimensional gel systems for small field dosimetry; however, precise film dosimetry can be technically challenging. We report here measurements for fractionated stereotactic radiation therapy (FSRT) delivered using volumetric modulated arc therapy (VMAT) to investigate the accuracy and reproducibility of film measurements with a novel in-house readout system. We show that radiochromic film can accurately and reproducibly validate FSRT deliveries and alsomore » benchmark our gel dosimetry work. Methods: VMAT FSRT plans for metastases alone (PTV{sub MET}) and whole brain plus metastases (WB+PTV{sub MET}) were delivered onto a multi-configurational phantom with a sheet of EBT3 Gafchromic film inserted mid-plane. A dose of 400 cGy was prescribed to 4 small PTV{sub MET} structures in the phantom, while a WB structure was prescribed a dose of 200 cGy in the WB+PTV{sub MET} iterations. Doses generated from film readout with our in-house system were compared to treatment planned doses. Each delivery was repeated multiple times to assess reproducibility. Results and Conclusions: The reproducibility of film optical density readout was excellent throughout all experiments. Doses measured from the film agreed well with plans for the WB+PTV{sub MET} delivery. But, film doses for PTV{sub MET} only deliveries were significantly below planned doses. This discrepancy is due to stray/scattered light perturbations in our system during readout. Corrections schemes will be presented.« less

  18. Energy absorption buildup factors, exposure buildup factors and Kerma for optically stimulated luminescence materials and their tissue equivalence for radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Singh, Vishwanath P.; Badiger, N. M.

    2014-11-01

    Optically stimulated luminescence (OSL) materials are sensitive dosimetric materials used for precise and accurate dose measurement for low-energy ionizing radiation. Low dose measurement capability with improved sensitivity makes these dosimeters very useful for diagnostic imaging, personnel monitoring and environmental radiation dosimetry. Gamma ray energy absorption buildup factors and exposure build factors were computed for OSL materials using the five-parameter Geometric Progression (G-P) fitting method in the energy range 0.015-15 MeV for penetration depths up to 40 mean free path. The computed energy absorption buildup factor and exposure buildup factor values were studied as a function of penetration depth and incident photon energy. Effective atomic numbers and Kerma relative to air of the selected OSL materials and tissue equivalence were computed and compared with that of water, PMMA and ICRU standard tissues. The buildup factors and kerma relative to air were found dependent upon effective atomic numbers. Buildup factors determined in the present work should be useful in radiation dosimetry, medical diagnostics and therapy, space dosimetry, accident dosimetry and personnel monitoring.

  19. [Hospital information system performance for road traffic accidents analysis in a hospital recruitment based area].

    PubMed

    Jannot, A-S; Fauconnier, J

    2013-06-01

    Road traffic accidents in France are mainly analyzed through reports completed by the security forces (police and gendarmerie). But the hospital information systems can also identify road traffic accidents via specific documentary codes of the International Classification of Diseases (ICD-10). The aim of this study was therefore to determine whether hospital stays consecutive to road traffic accident were truly identified by these documentary codes in a facility that collects data routinely and to study the consistency of results from hospital information systems and from security forces during the 2002-2008 period. We retrieved all patients for whom a documentary code for road traffic accident was entered in 2002-2008. We manually checked the concordance of documentary code for road traffic accident and trauma origin in 350 patient files. The number of accidents in the Grenoble area was then inferred by combining with hospitalization regional data and compared to the number of persons injured by traffic accidents declared by the security force. These hospital information systems successfully report road traffic accidents with 96% sensitivity (95%CI: [92%, 100%]) and 97% specificity (95%CI: [95%, 99%]). The decrease in road traffic accidents observed was significantly less than that observed was significantly lower than that observed in the data from the security force (45% for security force data against 27% for hospital data). Overall, this study shows that hospital information systems are a powerful tool for studying road traffic accidents morbidity in hospital and are complementary to security force data. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  20. Develop real-time dosimetry concepts and instrumentation for long term missions

    NASA Technical Reports Server (NTRS)

    Braby, L. A.

    1981-01-01

    The development of a rugged portable dosimetry system, based on microdosimetry techniques, which will measure dose and evaluate dose equivalent in a mixed radiation field is described. Progress in the desired dosimetry system can be divided into three distinct areas: development of the radiation detector, and electron system are presented. The mathematical techniques required are investigated.

  1. Dosimetry procedures for an industrial irradiation plant

    NASA Astrophysics Data System (ADS)

    Grahn, Ch.

    Accurate and reliable dosimetry procedures constitute a very important part of process control and quality assurance at a radiation processing plant. γ-Dose measurements were made on the GBS 84 irradiator for food and other products on pallets or in containers. Chemical dosimeters wre exposed in the facility under conditions of the typical plant operation. The choice of the dosimeter systems employed was based on the experience in chemical dosimetry gained over several years. Dose uniformity information was obtained in air, spices, bulbs, feeds, cosmetics, plastics and surgical goods. Most products currently irradiated require dose uniformity which can be efficiently provided by pallet or box irradiators like GBS 84. The radiation performance characteristics and some dosimetry procedures are discussed.

  2. TU-F-201-01: General Aspects of Radiochromic Film Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Niroomand-Rad, A.

    Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to)more » external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.« less

  3. Evaluation of radiochromic gel dosimetry and polymer gel dosimetry in a clinical dose verification

    NASA Astrophysics Data System (ADS)

    Vandecasteele, Jan; De Deene, Yves

    2013-09-01

    A quantitative comparison of two full three-dimensional (3D) gel dosimetry techniques was assessed in a clinical setting: radiochromic gel dosimetry with an in-house developed optical laser CT scanner and polymer gel dosimetry with magnetic resonance imaging (MRI). To benchmark both gel dosimeters, they were exposed to a 6 MV photon beam and the depth dose was compared against a diamond detector measurement that served as golden standard. Both gel dosimeters were found accurate within 4% accuracy. In the 3D dose matrix of the radiochromic gel, hotspot dose deviations up to 8% were observed which are attributed to the fabrication procedure. The polymer gel readout was shown to be sensitive to B0 field and B1 field non-uniformities as well as temperature variations during scanning. The performance of the two gel dosimeters was also evaluated for a brain tumour IMRT treatment. Both gel measured dose distributions were compared against treatment planning system predicted dose maps which were validated independently with ion chamber measurements and portal dosimetry. In the radiochromic gel measurement, two sources of deviations could be identified. Firstly, the dose in a cluster of voxels near the edge of the phantom deviated from the planned dose. Secondly, the presence of dose hotspots in the order of 10% related to inhomogeneities in the gel limit the clinical acceptance of this dosimetry technique. Based on the results of the micelle gel dosimeter prototype presented here, chemical optimization will be subject of future work. Polymer gel dosimetry is capable of measuring the absolute dose in the whole 3D volume within 5% accuracy. A temperature stabilization technique is incorporated to increase the accuracy during short measurements, however keeping the temperature stable during long measurement times in both calibration phantoms and the volumetric phantom is more challenging. The sensitivity of MRI readout to minimal temperature fluctuations is demonstrated which

  4. Automatic neutron dosimetry system based on fluorescent nuclear track detector technology.

    PubMed

    Akselrod, M S; Fomenko, V V; Bartz, J A; Haslett, T L

    2014-10-01

    For the first time, the authors are describing an automatic fluorescent nuclear track detector (FNTD) reader for neutron dosimetry. FNTD is a luminescent integrating type of detector made of aluminium oxide crystals that does not require electronics or batteries during irradiation. Non-destructive optical readout of the detector is performed using a confocal laser scanning fluorescence imaging with near-diffraction limited resolution. The fully automatic table-top reader allows one to load up to 216 detectors on a tray, read their engraved IDs using a CCD camera and optical character recognition, scan and process simultaneously two types of images in fluorescent and reflected laser light contrast to eliminate false-positive tracks related to surface and volume crystal imperfections. The FNTD dosimetry system allows one to measure neutron doses from 0.1 mSv to 20 Sv and covers neutron energies from thermal to 20 MeV. The reader is characterised by a robust, compact optical design, fast data processing electronics and user-friendly software. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. An application of artificial neural intelligence for personal dose assessment using a multi-area OSL dosimetry system.

    PubMed

    Lee, S Y; Kim, B H; Lee, K J

    2001-06-01

    Significant advances have been made in recent years to improve measurement technology and performance of phosphor materials in the fields of optically stimulated luminescence (OSL) dosimetry. Pulsed and continuous wave OSL studies recently carried out on alpha-Al2O3:C have shown that the material seems to be the most promising for routine application of OSL for dosimetric purposes. The main objective of the study is to propose a new personal dosimetry system using alpha-Al2O3:C by taking advantage of its optical properties and energy dependencies. In the process of the study, a new dose assessment algorithm was developed using artificial neural networks in hopes of achieving a higher degree of accuracy and precision in personal OSL dosimetry system. The original hypothesis of this work is that the spectral information of X- and gamma-ray fields may be obtained by the analysis of the response of a multi-element system. In this study, a feedforward neural network using the error back-propagation method with Bayesian optimization was applied for the response unfolding procedure. The validation of the proposed algorithm was investigated by unfolding the 10 measured responses of alpha-Al2O3:C for arbitrarily mixed photon fields which range from 20 to 662 keV. c2001 Elsevier Science Ltd. All rights reserved.

  6. Changes in Occupational Radiation Exposures after Incorporation of a Real-time Dosimetry System in the Interventional Radiology Suite.

    PubMed

    Poudel, Sashi; Weir, Lori; Dowling, Dawn; Medich, David C

    2016-08-01

    A statistical pilot study was retrospectively performed to analyze potential changes in occupational radiation exposures to Interventional Radiology (IR) staff at Lawrence General Hospital after implementation of the i2 Active Radiation Dosimetry System (Unfors RaySafe Inc, 6045 Cochran Road Cleveland, OH 44139-3302). In this study, the monthly OSL dosimetry records obtained during the eight-month period prior to i2 implementation were normalized to the number of procedures performed during each month and statistically compared to the normalized dosimetry records obtained for the 8-mo period after i2 implementation. The resulting statistics included calculation of the mean and standard deviation of the dose equivalences per procedure and included appropriate hypothesis tests to assess for statistically valid differences between the pre and post i2 study periods. Hypothesis testing was performed on three groups of staff present during an IR procedure: The first group included all members of the IR staff, the second group consisted of the IR radiologists, and the third group consisted of the IR technician staff. After implementing the i2 active dosimetry system, participating members of the Lawrence General IR staff had a reduction in the average dose equivalence per procedure of 43.1% ± 16.7% (p = 0.04). Similarly, Lawrence General IR radiologists had a 65.8% ± 33.6% (p=0.01) reduction while the technologists had a 45.0% ± 14.4% (p=0.03) reduction.

  7. Natural hazard impacts on transport systems: analyzing the data base of transport accidents in Russia

    NASA Astrophysics Data System (ADS)

    Petrova, Elena

    2015-04-01

    We consider a transport accident as any accident that occurs during transportation of people and goods. It comprises of accidents involving air, road, rail, water, and pipeline transport. With over 1.2 million people killed each year, road accidents are one of the world's leading causes of death; another 20-50 million people are injured each year on the world's roads while walking, cycling, or driving. Transport accidents of other types including air, rail, and water transport accidents are not as numerous as road crashes, but the relative risk of each accident is much higher because of the higher number of people killed and injured per accident. Pipeline ruptures cause large damages to the environment. That is why safety and security are of primary concern for any transport system. The transport system of the Russian Federation (RF) is one of the most extensive in the world. It includes 1,283,000 km of public roads, more than 600,000 km of airlines, more than 200,000 km of gas, oil, and product pipelines, 115,000 km of inland waterways, and 87,000 km of railways. The transport system, especially the transport infrastructure of the country is exposed to impacts of various natural hazards and weather extremes such as heavy rains, snowfalls, snowdrifts, floods, earthquakes, volcanic eruptions, landslides, snow avalanches, debris flows, rock falls, fog or icing roads, and other natural factors that additionally trigger many accidents. In June 2014, the Ministry of Transport of the RF has compiled a new version of the Transport Strategy of the RF up to 2030. Among of the key pillars of the Strategy are to increase the safety of the transport system and to reduce negative environmental impacts. Using the data base of technological accidents that was created by the author, the study investigates temporal variations and regional differences of the transport accidents' risk within the Russian federal regions and a contribution of natural factors to occurrences of different

  8. WE-F-201-03: Evaluate Clinical Cases Using Commercially Available Systems and Compare to TG-43 Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Beaulieu, L.

    With the recent introduction of heterogeneity correction algorithms for brachytherapy, the AAPM community is still unclear on how to commission and implement these into clinical practice. The recently-published AAPM TG-186 report discusses important issues for clinical implementation of these algorithms. A charge of the AAPM-ESTRO-ABG Working Group on MBDCA in Brachytherapy (WGMBDCA) is the development of a set of well-defined test case plans, available as references in the software commissioning process to be performed by clinical end-users. In this practical medical physics course, specific examples on how to perform the commissioning process are presented, as well as descriptions of themore » clinical impact from recent literature reporting comparisons of TG-43 and heterogeneity-based dosimetry. Learning Objectives: Identify key clinical applications needing advanced dose calculation in brachytherapy. Review TG-186 and WGMBDCA guidelines, commission process, and dosimetry benchmarks. Evaluate clinical cases using commercially available systems and compare to TG-43 dosimetry.« less

  9. Urban pedestrian accident countermeasures experimental evaluation. Volume 2, Accident studies

    DOT National Transportation Integrated Search

    1975-02-01

    A pedestrian accident data collection system was established in six major cities. The system involved using the regular police accident report form and a specifically designed supplementary data form. The information on the forms was combined, and th...

  10. Predicting System Accidents with Model Analysis During Hybrid Simulation

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Fleming, Land D.; Throop, David R.

    2002-01-01

    Standard discrete event simulation is commonly used to identify system bottlenecks and starving and blocking conditions in resources and services. The CONFIG hybrid discrete/continuous simulation tool can simulate such conditions in combination with inputs external to the simulation. This provides a means for evaluating the vulnerability to system accidents of a system's design, operating procedures, and control software. System accidents are brought about by complex unexpected interactions among multiple system failures , faulty or misleading sensor data, and inappropriate responses of human operators or software. The flows of resource and product materials play a central role in the hazardous situations that may arise in fluid transport and processing systems. We describe the capabilities of CONFIG for simulation-time linear circuit analysis of fluid flows in the context of model-based hazard analysis. We focus on how CONFIG simulates the static stresses in systems of flow. Unlike other flow-related properties, static stresses (or static potentials) cannot be represented by a set of state equations. The distribution of static stresses is dependent on the specific history of operations performed on a system. We discuss the use of this type of information in hazard analysis of system designs.

  11. 'Remixing Rasmussen': The evolution of Accimaps within systemic accident analysis.

    PubMed

    Waterson, Patrick; Jenkins, Daniel P; Salmon, Paul M; Underwood, Peter

    2017-03-01

    Throughout Jens Rasmussen's career there has been a continued emphasis on the development of methods, techniques and tools for accident analysis and investigation. In this paper we focus on the evolution and development of one specific example, namely Accimaps and their use for accident analysis. We describe the origins of Accimaps followed by a review of 27 studies which have applied and adapted Accimaps over the period 2000-2015 to a range of domains and types of accident. Aside from demonstrating the versatility and popularity of the method, part of the motivation for the review of the use of Accimaps is to address the question of what constitutes a sound, usable, valid and reliable approach to systemic accident analysis. The findings from the review demonstrate continuity with the work carried out by Rasmussen, as well as significant variation (e.g., changes to the Accimap, used of additional theoretical and practice-oriented perspectives on safety). We conclude the paper with some speculations regarding future extension and adaptation of the Accimap approach including the possibility of using hybrid models for accident analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Verification of intensity modulated radiation therapy beams using a tissue equivalent plastic scintillator dosimetry system

    NASA Astrophysics Data System (ADS)

    Petric, Martin Peter

    This thesis describes the development and implementation of a novel method for the dosimetric verification of intensity modulated radiation therapy (IMRT) fields with several advantages over current techniques. Through the use of a tissue equivalent plastic scintillator sheet viewed by a charge-coupled device (CCD) camera, this method provides a truly tissue equivalent dosimetry system capable of efficiently and accurately performing field-by-field verification of IMRT plans. This work was motivated by an initial study comparing two IMRT treatment planning systems. The clinical functionality of BrainLAB's BrainSCAN and Varian's Helios IMRT treatment planning systems were compared in terms of implementation and commissioning, dose optimization, and plan assessment. Implementation and commissioning revealed differences in the beam data required to characterize the beam prior to use with the BrainSCAN system requiring higher resolution data compared to Helios. This difference was found to impact on the ability of the systems to accurately calculate dose for highly modulated fields, with BrainSCAN being more successful than Helios. The dose optimization and plan assessment comparisons revealed that while both systems use considerably different optimization algorithms and user-control interfaces, they are both capable of producing substantially equivalent dose plans. The extensive use of dosimetric verification techniques in the IMRT treatment planning comparison study motivated the development and implementation of a novel IMRT dosimetric verification system. The system consists of a water-filled phantom with a tissue equivalent plastic scintillator sheet built into the top surface. Scintillation light is reflected by a plastic mirror within the phantom towards a viewing window where it is captured using a CCD camera. Optical photon spread is removed using a micro-louvre optical collimator and by deconvolving a glare kernel from the raw images. Characterization of this

  13. MO-B-BRB-03: 3D Dosimetry in the Clinic: Validating Special Techniques

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Juang, T.

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by themore » development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data

  14. MO-B-BRB-01: 3D Dosimetry in the Clinic: Background and Motivation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schreiner, L.

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by themore » development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data

  15. Analysis of helium purification system capability during water ingress accident in RDE

    NASA Astrophysics Data System (ADS)

    Sriyono; Kusmastuti, Rahayu; Bakhri, Syaiful; Sunaryo, Geni Rina

    2018-02-01

    The water ingress accident caused by steam generator tube rupture (SGTR) in RDE (Experimental Power Reactor) must be anticipated. During the accident, steam from secondary system diffused and mixed with helium gas in the primary coolant. To avoid graphite corrosion in the core, steam will be removed by Helium purification system (HPS). There are two trains in HPS, first train for normal operation and the second for the regeneration and accident. The second train is responsible to clean the coolant during accident condition. The second train is equipped with additional component, i.e. water cooler, post accident blower, and water separator to remove this mixture gas. During water ingress, the water release from rupture tube is mixed with helium gas. The water cooler acts as a steam condenser, where the steam will be separated by water separator from the helium gas. This paper analyses capability of HPS during water ingress accident. The goal of the research is to determine the time consumed by HPS to remove the total amount of water ingress. The method used is modelling and simulation of the HPS by using ChemCAD software. The BDBA and DBA scenarios will be simulated. In BDBA scenario, up to 110 kg of water is assumed to infiltrate to primary coolant while DBA is up to 35 kg. By using ChemCAD simulation, the second train will purify steam ingress maximum in 0.5 hours. The HPS of RDE has a capability to anticipate the water ingress accident.

  16. Characterization of an in vivo diode dosimetry system for clinical use

    PubMed Central

    Huang, Kai; Bice, William S.; Hidalgo‐Salvatierra, Oscar

    2003-01-01

    An in vivo dosimetry system that uses p‐type semiconductor diodes with buildup caps was characterized for clinical use on accelerators ranging in energy from 4 to 18 MV. The dose per pulse dependence was investigated. This was done by altering the source‐surface distance, field size, and wedge for photons. The off‐axis correction and effect of changing repetition rate were also investigated. A model was developed to fit the measured two‐dimensional diode correction factors. PACS number(s): 87.66.–a, 87.52.–g PMID:12777148

  17. Thin film tritium dosimetry

    DOEpatents

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  18. Development of an accident duration prediction model on the Korean Freeway Systems.

    PubMed

    Chung, Younshik

    2010-01-01

    Since duration prediction is one of the most important steps in an accident management process, there have been several approaches developed for modeling accident duration. This paper presents a model for the purpose of accident duration prediction based on accurately recorded and large accident dataset from the Korean Freeway Systems. To develop the duration prediction model, this study utilizes the log-logistic accelerated failure time (AFT) metric model and a 2-year accident duration dataset from 2006 to 2007. Specifically, the 2006 dataset is utilized to develop the prediction model and then, the 2007 dataset was employed to test the temporal transferability of the 2006 model. Although the duration prediction model has limitations such as large prediction error due to the individual differences of the accident treatment teams in terms of clearing similar accidents, the results from the 2006 model yielded a reasonable prediction based on the mean absolute percentage error (MAPE) scale. Additionally, the results of the statistical test for temporal transferability indicated that the estimated parameters in the duration prediction model are stable over time. Thus, this temporal stability suggests that the model may have potential to be used as a basis for making rational diversion and dispatching decisions in the event of an accident. Ultimately, such information will beneficially help in mitigating traffic congestion due to accidents.

  19. Wet weather highway accident analysis and skid resistance data management system (volume I).

    DOT National Transportation Integrated Search

    1992-06-01

    The objectives and scope of this research are to establish an effective methodology for wet weather accident analysis and to develop a database management system to facilitate information processing and storage for the accident analysis process, skid...

  20. Comparison of dose response functions for EBT3 model GafChromic™ film dosimetry system.

    PubMed

    Aldelaijan, Saad; Devic, Slobodan

    2018-05-01

    Different dose response functions of EBT3 model GafChromic™ film dosimetry system have been compared in terms of sensitivity as well as uncertainty vs. error analysis. We also made an assessment of the necessity of scanning film pieces before and after irradiation. Pieces of EBT3 film model were irradiated to different dose values in Solid Water (SW) phantom. Based on images scanned in both reflection and transmission mode before and after irradiation, twelve different response functions were calculated. For every response function, a reference radiochromic film dosimetry system was established by generating calibration curve and by performing the error vs. uncertainty analysis. Response functions using pixel values from the green channel demonstrated the highest sensitivity in both transmission and reflection mode. All functions were successfully fitted with rational functional form, and provided an overall one-sigma uncertainty of better than 2% for doses above 2 Gy. Use of pre-scanned images to calculate response functions resulted in negligible improvement in dose measurement accuracy. Although reflection scanning mode provides higher sensitivity and could lead to a more widespread use of radiochromic film dosimetry, it has fairly limited dose range and slightly increased uncertainty when compared to transmission scan based response functions. Double-scanning technique, either in transmission or reflection mode, shows negligible improvement in dose accuracy as well as a negligible increase in dose uncertainty. Normalized pixel value of the images scanned in transmission mode shows linear response in a dose range of up to 11 Gy. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  1. Topical Review: Polymer gel dosimetry

    PubMed Central

    Baldock, C; De Deene, Y; Doran, S; Ibbott, G; Jirasek, A; Lepage, M; McAuley, K B; Oldham, M; Schreiner, L J

    2010-01-01

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented. PMID:20150687

  2. Electron paramagnetic resonance (EPR) dosimetry using lithium formate in radiotherapy: comparison with thermoluminescence (TL) dosimetry using lithium fluoride rods.

    PubMed

    Vestad, Tor Arne; Malinen, Eirik; Olsen, Dag Rune; Hole, Eli Olaug; Sagstuen, Einar

    2004-10-21

    Solid-state radiation dosimetry by electron paramagnetic resonance (EPR) spectroscopy and thermoluminescence (TL) was utilized for the determination of absorbed doses in the range of 0.5-2.5 Gy. The dosimeter materials used were lithium formate and lithium fluoride (TLD-100 rods) for EPR dosimetry and TL dosimetry, respectively. 60Co gamma-rays and 4, 6, 10 and 15 MV x-rays were employed. The main objectives were to compare the variation in dosimeter reading of the respective dosimetry systems and to determine the photon energy dependence of the two dosimeter materials. The EPR dosimeter sensitivity was constant over the dose range in question, while the TL sensitivity increased by more than 5% from 0.5 to 2.5 Gy, thus displaying a supralinear dose response. The average relative standard deviation in the dosimeter reading per dose was 3.0% and 1.2% for the EPR and TL procedures, respectively. For EPR dosimeters, the relative standard deviation declined significantly from 4.3% to 1.1% over the dose range in question. The dose-to-water energy response for the megavoltage x-ray beams relative to 60Co gamma-rays was in the range of 0.990-0.979 and 0.984-0.962 for lithium formate and lithium fluoride, respectively. The results show that EPR dosimetry with lithium formate provides dose estimates with a precision comparable to that of TL dosimetry (using lithium fluoride) for doses above 2 Gy, and that lithium formate is slightly less dependent on megavoltage photon beam energy than lithium fluoride.

  3. Electron paramagnetic resonance (EPR) dosimetry using lithium formate in radiotherapy: comparison with thermoluminescence (TL) dosimetry using lithium fluoride rods

    NASA Astrophysics Data System (ADS)

    Vestad, Tor Arne; Malinen, Eirik; Rune Olsen, Dag; Olaug Hole, Eli; Sagstuen, Einar

    2004-10-01

    Solid-state radiation dosimetry by electron paramagnetic resonance (EPR) spectroscopy and thermoluminescence (TL) was utilized for the determination of absorbed doses in the range of 0.5-2.5 Gy. The dosimeter materials used were lithium formate and lithium fluoride (TLD-100 rods) for EPR dosimetry and TL dosimetry, respectively. 60Co ggr-rays and 4, 6, 10 and 15 MV x-rays were employed. The main objectives were to compare the variation in dosimeter reading of the respective dosimetry systems and to determine the photon energy dependence of the two dosimeter materials. The EPR dosimeter sensitivity was constant over the dose range in question, while the TL sensitivity increased by more than 5% from 0.5 to 2.5 Gy, thus displaying a supralinear dose response. The average relative standard deviation in the dosimeter reading per dose was 3.0% and 1.2% for the EPR and TL procedures, respectively. For EPR dosimeters, the relative standard deviation declined significantly from 4.3% to 1.1% over the dose range in question. The dose-to-water energy response for the megavoltage x-ray beams relative to 60Co ggr-rays was in the range of 0.990-0.979 and 0.984-0.962 for lithium formate and lithium fluoride, respectively. The results show that EPR dosimetry with lithium formate provides dose estimates with a precision comparable to that of TL dosimetry (using lithium fluoride) for doses above 2 Gy, and that lithium formate is slightly less dependent on megavoltage photon beam energy than lithium fluoride.

  4. Accident investigation

    NASA Technical Reports Server (NTRS)

    Laynor, William G. Bud

    1987-01-01

    The National Transportation Safety Board (NTSB) has attributed wind shear as a cause or contributing factor in 15 accidents involving transport-categroy airplanes since 1970. Nine of these were nonfatal; but the other six accounted for 440 lives. Five of the fatal accidents and seven of the nonfatal accidents involved encounters with convective downbursts or microbursts. Of other accidents, two which were nonfatal were encounters with a frontal system shear, and one which was fatal was the result of a terrain induced wind shear. These accidents are discussed with reference to helping the aircraft to avoid the wind shear or if impossible to help the pilot to get through the wind shear.

  5. SU-F-T-52: Study of Energy Dependent Effect of Dosimetry Systems Used in Therapeutic Soft X-Ray Energy Range

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Souri, S; Qian, X; Gill, G

    Purpose: To investigate energy dependent effects of different dosimetry systems which can be used as in vivo dosimetry monitoring for intraoperative radiotherapy in therapeutic soft x-ray energy range. Methods: Three dosimetry systems were evaluated in therapeutic soft x-ray energy range: optically stimulated luminescent dosimeter (OSLD) nanoDots, radiochromic EBT2 and EBT3 films. The x-ray photons were produced by a Zeiss Intrabeam 50 kV x-ray radiotherapy system. Solid water and bolus slabs with different thicknesses were used in the process of irradiation. An aluminum filter set was used to measure HVLs of X-rays. Calibration curves were made at different depth of boluses.more » Results: Half Value Layers at depths of 0, 3, 10, and 20 mm of solid water were measured to represent the energy change versus depth, yielding 0.306, 0.482, 0.865 and 0.901 respectively and indicating nearly unchanged HVL beyond 1 cm depth. The responses of each system at different depths were normalized to the response at 2 cm depth. In film dosimetry, the response is calculated as optical density (OD). The results show that there is nearly the same energy dependence for EBT2 and EBT3. At a HVL of 0.482 mm Al, the relative responses of nanoDots and EBT3 are 0.85 ± 0.04 and 0.89 ± 0.03 compared to those at 0.901 mm Al HVL, respectively, indicating no obvious difference between those two systems within the measurement uncertainty. Conclusion: It was observed that the studied dosimeter response increases about 13% from the x-ray energy of 0.48 mm Al to 0.90 mm Al. Therefore, caution should be exercised in using an appropriate calibration curve, and x-ray beam hardening effect has to be taken into account.« less

  6. Thermoluminescent dosimetry in veterinary diagnostic radiology.

    PubMed

    Hernández-Ruiz, L; Jimenez-Flores, Y; Rivera-Montalvo, T; Arias-Cisneros, L; Méndez-Aguilar, R E; Uribe-Izquierdo, P

    2012-12-01

    This paper presents the results of Environmental and Personnel Dosimetry made in a radiology area of a veterinary hospital. Dosimetry was realized using thermoluminescent (TL) materials. Environmental Dosimetry results show that areas closer to the X-ray equipment are safe. Personnel Dosimetry shows important measurements of daily workday in some persons near to the limit established by ICRP. TL results of radiation measurement suggest TLDs are good candidates as a dosimeter to radiation dosimetry in veterinary radiology. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. UK guidance on the management of personal dosimetry systems for healthcare staff working at multiple organizations.

    PubMed

    Rogers, Andy; Chapple, Claire-Louise; Murray, Maria; Platton, David; Saunderson, John

    2017-11-01

    There has been concern expressed by the UK regulator, the Health & Safety Executive, regarding the management of occupation dose for healthcare radiation workers who work across multiple organizations. In response to this concern, the British Institute of Radiology led a working group of relevant professional bodies to develop guidance in this area. The guidance addresses issues of general system management that would apply to all personal dosimetry systems, regardless of whether or not the workers within that system work across organizational boundaries, along with exploring efficient strategies to comply with legislation where those workers do indeed work across organizational boundaries. For those specific instances, the guidance discusses both system requirements to enable organizations to co-operate (Ionising Radiation Regulations 1999 Regulation 15), as well as specific instances of staff exposure. This is broken down into three categories-low, medium and high risk. A suggested approach to each is given to guide employers and their radiation advisers in adopting sensible strategies for the monitoring of their staff and the subsequent sharing of dosimetry data to ensure overall compliance with both dose limits and optimization requirements.

  8. Quantitative imaging for clinical dosimetry

    NASA Astrophysics Data System (ADS)

    Bardiès, Manuel; Flux, Glenn; Lassmann, Michael; Monsieurs, Myriam; Savolainen, Sauli; Strand, Sven-Erik

    2006-12-01

    Patient-specific dosimetry in nuclear medicine is now a legal requirement in many countries throughout the EU for targeted radionuclide therapy (TRT) applications. In order to achieve that goal, an increased level of accuracy in dosimetry procedures is needed. Current research in nuclear medicine dosimetry should not only aim at developing new methods to assess the delivered radiation absorbed dose at the patient level, but also to ensure that the proposed methods can be put into practice in a sufficient number of institutions. A unified dosimetry methodology is required for making clinical outcome comparisons possible.

  9. Optically stimulated luminescence (OSL) dosimetry in medicine.

    PubMed

    Yukihara, E G; McKeever, S W S

    2008-10-21

    This paper reviews fundamental and practical aspects of optically stimulated luminescence (OSL) dosimetry pertaining to applications in medicine, having particularly in mind new researchers and medical physicists interested in gaining familiarity with the field. A basic phenomenological model for OSL is presented and the key processes affecting the outcome of an OSL measurement are discussed. Practical aspects discussed include stimulation modalities (continuous-wave OSL, pulsed OSL and linear modulation OSL), basic experimental setup, available OSL readers, optical fiber systems and basic properties of available OSL dosimeters. Finally, results from the recent literature on applications of OSL in radiotherapy, radiodiagnostics and heavy charged particle dosimetry are discussed in light of the theoretical and practical framework presented in this review. Open questions and future challenges in OSL dosimetry are highlighted as a guide to the research needed to further advance the field.

  10. STAMP-Based HRA Considering Causality Within a Sociotechnical System: A Case of Minuteman III Missile Accident.

    PubMed

    Rong, Hao; Tian, Jin

    2015-05-01

    The study contributes to human reliability analysis (HRA) by proposing a method that focuses more on human error causality within a sociotechnical system, illustrating its rationality and feasibility by using a case of the Minuteman (MM) III missile accident. Due to the complexity and dynamics within a sociotechnical system, previous analyses of accidents involving human and organizational factors clearly demonstrated that the methods using a sequential accident model are inadequate to analyze human error within a sociotechnical system. System-theoretic accident model and processes (STAMP) was used to develop a universal framework of human error causal analysis. To elaborate the causal relationships and demonstrate the dynamics of human error, system dynamics (SD) modeling was conducted based on the framework. A total of 41 contributing factors, categorized into four types of human error, were identified through the STAMP-based analysis. All factors are related to a broad view of sociotechnical systems, and more comprehensive than the causation presented in the accident investigation report issued officially. Recommendations regarding both technical and managerial improvement for a lower risk of the accident are proposed. The interests of an interdisciplinary approach provide complementary support between system safety and human factors. The integrated method based on STAMP and SD model contributes to HRA effectively. The proposed method will be beneficial to HRA, risk assessment, and control of the MM III operating process, as well as other sociotechnical systems. © 2014, Human Factors and Ergonomics Society.

  11. Iron-based radiochromic systems for UV dosimetry applications

    NASA Astrophysics Data System (ADS)

    Lee, Hannah J.; Alqathami, Mamdooh; Blencowe, Anton; Ibbott, Geoffrey

    2018-01-01

    Phototherapy treatment using ultraviolet (UV) A and B light sources has long existed as a treatment option for various skin conditions. Quality control for phototherapy treatment recommended by the British Association of Dermatologists and British Photodermatology Group generally focused on instrumentation-based dosimetry measurements. The purpose of this study was to present an alternative, easily prepared dosimeter system for the measurement of UV dose and as a simple quality assurance technique for phototherapy treatments. Five different UVA-sensitive radiochromic dosimeter formulations were investigated and responded with a measurable and visible optical change both in solution and in gel form. Iron(III) reduction reaction formulations were found to be more sensitive to UVA compared to iron(II) oxidation formulations. One iron(III) reduction formulation was found to be especially promising due to its sensitivity to UVA dose, ease of production, and linear response up to a saturation point.

  12. A system for electron therapy dosimetry surveys with thermoluminescence dosimeters.

    PubMed

    Soares, C G; Ehrlich, M; Padikal, T N; Gromadzki, Z C

    1982-11-01

    Radiation-therapy dosimetry surveys employing thermoluminescence dosimeters (TLDs) are now being considered for high-energy electron beams. Using a system of individually calibrated pressed LiF TLDs in a water and a polystyrene phantom, we established that the distortions of depth-dose distributions in non-conducting materials previously observed at high absorbed doses and high dose rates were not detectable in the present geometry at doses and dose rates as much as 40 times higher than those employed in radiation therapy. The system was then used to measure TLD response in water and in polystyrene in the nominal electron-energy range from 7 to 18 MeV. In the water phantom, the well-known trend for TLD response to decrease with increasing electron energy was observed. In the polystyrene phantom, TLD response was found to be independent of electron energy.

  13. Twenty new ISO standards on dosimetry for radiation processing

    NASA Astrophysics Data System (ADS)

    Farrar, H., IV

    2000-03-01

    Twenty standards on essentially all aspects of dosimetry for radiation processing were published as new ISO standards in December 1998. The standards are based on 20 standard practices and guides developed over the past 14 years by Subcommittee E10.01 of the American Society for Testing and Materials (ASTM). The transformation to ISO standards using the 'fast track' process under ISO Technical Committee 85 (ISO/TC85) commenced in 1995 and resulted in some overlap of technical information between three of the new standards and the existing ISO Standard 11137 Sterilization of health care products — Requirements for validation and routine control — Radiation sterilization. Although the technical information in these four standards was consistent, compromise wording in the scopes of the three new ISO standards to establish precedence for use were adopted. Two of the new ISO standards are specifically for food irradiation applications, but the majority apply to all forms of gamma, X-ray, and electron beam radiation processing, including dosimetry for sterilization of health care products and the radiation processing of fruit, vegetables, meats, spices, processed foods, plastics, inks, medical wastes, and paper. Most of the standards provide exact procedures for using individual dosimetry systems or for characterizing various types of irradiation facilities, but one covers the selection and calibration of dosimetry systems, and another covers the treatment of uncertainties using the new ISO Type A and Type B evaluations. Unfortunately, nine of the 20 standards just adopted by the ISO are not the most recent versions of these standards and are therefore already out of date. To help solve this problem, efforts are being made to develop procedures to coordinate the ASTM and ISO development and revision processes for these and future ASTM-originating dosimetry standards. In the meantime, an additional four dosimetry standards have recently been published by the ASTM but

  14. [Development of medical emergency response system for accidents due to chemicals in Chongqing municipality].

    PubMed

    Ning, Xu; Dong, Zhao-jun; Mu, Ling; Zhai, Jian-cai

    2006-12-01

    To plan and develop a Chongqing chemical accident rescue command system. Based on the modes of leakage and diffusion of various poisonous gases and chemicals, different modes of injuries produced, and their appropriate rescue and treatments, also taking the following factors such as the condition of storage of chemicals, meteorological and geographic conditions, medical institutions and equipment, and their rescuing capacity into consideration, a plan was drafted to establish the rescue system. Real-time simulation technology, data analysis, evaluation technology and database technology were employed in the planning. Using Visual Studio 6.0 as the software development platform, this project aimed to design the software of an emergency command system for chemical accidents in Chongqing which could be operated with the Windows 2000/XP operating system. This system provided a dynamic scope of the endangered area, casualty number estimates, and recommendation of measures and a rescue plan for various chemical accidents. Furthermore, the system helped retrieve comprehensive information regarding the physical and chemical characteristics of more than 4 200 dangerous poisonous chemicals and their appropriate treatment modalities. This system is easy to operate with a friendly interface, functions rapidly and can provide real-time analysis with comparatively precise results. This system could satisfy the requirements of executing the command and the rescue of a chemical accident with good prospects of application.

  15. An expert system for the quantification of fault rates in construction fall accidents.

    PubMed

    Talat Birgonul, M; Dikmen, Irem; Budayan, Cenk; Demirel, Tuncay

    2016-01-01

    Expert witness reports, prepared with the aim of quantifying fault rates among parties, play an important role in a court's final decision. However, conflicting fault rates assigned by different expert witness boards lead to iterative objections raised by the related parties. This unfavorable situation mainly originates due to the subjectivity of expert judgments and unavailability of objective information about the causes of accidents. As a solution to this shortcoming, an expert system based on a rule-based system was developed for the quantification of fault rates in construction fall accidents. The aim of developing DsSafe is decreasing the subjectivity inherent in expert witness reports. Eighty-four inspection reports prepared by the official and authorized inspectors were examined and root causes of construction fall accidents in Turkey were identified. Using this information, an evaluation form was designed and submitted to the experts. Experts were asked to evaluate the importance level of the factors that govern fall accidents and determine the fault rates under different scenarios. Based on expert judgments, a rule-based expert system was developed. The accuracy and reliability of DsSafe were tested with real data as obtained from finalized court cases. DsSafe gives satisfactory results.

  16. Human factors analysis and classification system applied to civil aircraft accidents in India.

    PubMed

    Gaur, Deepak

    2005-05-01

    The Human Factors Analysis and Classification System (HFACS) has gained wide acceptance as a tool to classify human factors in aircraft accidents and incidents. This study on application of HFACS to civil aircraft accident reports at Directorate General Civil of Aviation (DGCA), India, was conducted to ascertain the practicability of applying HFACS to existing investigation reports and to analyze the trends of human factor causes of civil aircraft accidents. Accident investigation reports held at DGCA, New Delhi, for the period 1990--99 were scrutinized. In all, 83 accidents occurred during this period, of which 48 accident reports were evaluated in this study. One or more human factors contributed to 37 of the 48 (77.1%) accidents. The commonest unsafe act was 'skill based errors' followed by 'decision errors.' Violations of laid down rules were contributory in 16 cases (33.3%). 'Preconditions for unsafe acts' were seen in 23 of the 48 cases (47.9%). A fairly large number (52.1%) had 'organizational influences' contributing to the accident. These results are in consonance with larger studies of accidents in the U.S. Navy and general aviation. Such a high percentage of 'organizational influences' has not been reported in other studies. This is a healthy sign for Indian civil aviation, provided effective remedial action for the same is undertaken.

  17. Applying STAMP in Accident Analysis

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy; Daouk, Mirna; Dulac, Nicolas; Marais, Karen

    2003-01-01

    Accident models play a critical role in accident investigation and analysis. Most traditional models are based on an underlying chain of events. These models, however, have serious limitations when used for complex, socio-technical systems. Previously, Leveson proposed a new accident model (STAMP) based on system theory. In STAMP, the basic concept is not an event but a constraint. This paper shows how STAMP can be applied to accident analysis using three different views or models of the accident process and proposes a notation for describing this process.

  18. The ENEA neutron personal dosimetry service.

    PubMed

    Morelli, B; Mariotti, F; Fantuzzi, E

    2006-01-01

    The ENEA Radiation Protection Institute has been operating the only neutron personal dosimetry service in Italy since the 1970s. Since the 1980s the service has been based on PADC (poly allyl diglycol carbonate) for fast neutron dosimetry, while thermal neutron dosimetry has been performed using thermoluminescence (TL) dosemeters. Since the service was started, a number of aspects have undergone evolution. The latest and most important changes are as follows: in 1998 a new PADC material was introduced in routine, since 2001 TL thermal dosimetry has been based on LiF(Mg,Cu,P) [GR-200] and (7)LiF(Mg,Cu,P) [GR-207] detectors and since 2003 a new image analysis reading system for the fast neutron dosemeters has been used. Herein an updated summary of how the service operates and performs today is presented. The approaches to calibration and traceability to estimate the quantity of H(p)(10) are mentioned. Results obtained at the performance test of dosimetric services in the EU member states and Switzerland sponsored by the European Commission and organised by Eurados in 1999 are reported. Last but not least, quality assurance (QA) procedures introduced in the routine operation to track the whole process of dose evaluation (i.e. plastic QA, acceptance test, test etching bath reproducibility and 'dummy customer' (blind test) for each issuing monitoring period) are presented and discussed.

  19. MO-B-BRB-02: 3D Dosimetry in the Clinic: IMRT Technique Validation in Sweden

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ceberg, S.

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by themore » development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data

  20. An Accident Precursor Analysis Process Tailored for NASA Space Systems

    NASA Technical Reports Server (NTRS)

    Groen, Frank; Stamatelatos, Michael; Dezfuli, Homayoon; Maggio, Gaspare

    2010-01-01

    Accident Precursor Analysis (APA) serves as the bridge between existing risk modeling activities, which are often based on historical or generic failure statistics, and system anomalies, which provide crucial information about the failure mechanisms that are actually operative in the system and which may differ in frequency or type from those in the various models. These discrepancies between the models (perceived risk) and the system (actual risk) provide the leading indication of an underappreciated risk. This paper presents an APA process developed specifically for NASA Earth-to-Orbit space systems. The purpose of the process is to identify and characterize potential sources of system risk as evidenced by anomalous events which, although not necessarily presenting an immediate safety impact, may indicate that an unknown or insufficiently understood risk-significant condition exists in the system. Such anomalous events are considered accident precursors because they signal the potential for severe consequences that may occur in the future, due to causes that are discernible from their occurrence today. Their early identification allows them to be integrated into the overall system risk model used to intbrm decisions relating to safety.

  1. Accidents involving Brazilian indigenous treated at urgent and emergency services of the Unified Health System.

    PubMed

    Souza, Edinilsa Ramos de; Njaine, Kathie; Mascarenhas, Márcio Dênis Medeiros; Oliveira, Maria Conceição de

    2016-12-01

    Abstract We analyzed the accidents with Brazilian indigenous treated at urgent and emergency services of the Unified Health System (SUS). Data were obtained from the 2014 Viva Survey, which included 86 services from 24 capitals and the Federal District. The demographic profile of the indigenous, the event and the attendance were characterized. Most of the attended people were male in the 20-39 years age group. Falls and traffic accidents were the main reasons for attendance. Alcohol use was informed by 5.6% of the attended people, a figure that increases to 19.1% in traffic accidents, 26.1% among drivers and 22.8% among motorcyclists. There was a statistical difference between genders in relation to age, disability, place of occurrence of the event, work-related event and victim's condition in the traffic accident. We emphasize the importance of providing visibility to accidents with indigenous and engage them in the prevention of such events. Data reliability depends on the adequate completion in indigenous health information systems.

  2. EPR/PTFE dosimetry for test reactor environments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vehar, D.W.; Griffin, P.J.; Quirk, T.J.

    2011-07-01

    The use of Electron Paramagnetic Resonance (EPR) spectroscopy with materials such as alanine is well established as a technique for measurement of ionizing radiation absorbed dose in photon and electron fields such as Co-60, high-energy bremsstrahlung and electron-beam fields [1]. In fact, EPR/Alanine dosimetry has become a routine transfer standard for national standards bodies such as NIST and NPL. In 1992 the Radiation Metrology Laboratory (RML) at Sandia National Laboratories implemented EPR/Alanine capabilities for use in routine and calibration activities at its Co-60 and pulsed-power facilities. At that time it also investigated the usefulness of the system for measurement ofmore » absorbed dose in the mixed neutron/photon environments of reactors such as the Sandia Pulsed Reactor and the Annular Core Research Reactor used for hardness testing of electronics. The RML concluded that the neutron response of alanine was a sufficiently high fraction of the overall dosimeter response that the resulting uncertainties in the photon dose would be unacceptably large for silicon-device testing. However, it also suggested that non-hydrogenous materials such as polytetrafluoroethylene (PTFE) would exhibit smaller neutron response and might be useful in mixed environments. Preliminary research with PTFE in photon environments indicated considerable promise, but further development was not pursued at that time. Because of renewed interest in absorbed dose measurements that could better define the individual contributions of photon and neutron components to the overall dose delivered to a test object, the RML has re-initiated the development of an EPR/PTFE dosimetry system. This effort consists of three stages: 1) Identification of PTFE materials that may be suitable for dosimetry applications. It was speculated that the inconsistency of EPR signatures in the earlier samples may have been due to variability in PTFE manufacturing processes. 2) Characterization of

  3. Reactor Dosimetry State of the Art 2008

    NASA Astrophysics Data System (ADS)

    Voorbraak, Wim; Debarberis, Luigi; D'Hondt, Pierre; Wagemans, Jan

    2009-08-01

    from the first-generation nuclear-powered submarines by gamma scanning / A. F. Usatyi. L. A. Serdyukova and B. S. Stepennov -- Oral session 3: Power plant surveillance. Upgraded neutron dosimetry procedure for VVER-440 surveillance specimens / V. Kochkin ... [et al.]. Neutron dosimetry on the full-core first generation VVER-440 aimed to reactor support structure load evaluation / P. Borodkin ... [et al.]. Ex-vessel neutron dosimetry programs for PWRs in Korea / C. S. Yoo. B. C. Kim and C. C. Kim. Comparison of irradiation conditions of VVER-1000 reactor pressure vessel and surveillance specimens for various core loadings / V. N. Bukanov ... [et al.]. Re-evaluation of dosimetry in the new surveillance program for the Loviisa 1 VVER-440 reactor / T. Serén -- Oral session 4: Benchmarks, intercomparisons and adjustment methods. Determination of the neutron parameter's uncertainties using the stochastic methods of uncertainty propagation and analysis / G. Grégoire ... [et al.].Covariance matrices for calculated neutron spectra and measured dosimeter responses / J. G. Williams ... [et al.]. The role of dosimetry at the high flux reactor / S. C. van der Marek ... [et al.]. Calibration of a manganese bath relative to Cf-252 nu-bar / D. M. Gilliam, A. T. Yue and M. Scott Dewey. Major upgrade of the reactor dosimetry interpretation methodology used at the CEA: general principle / C. Destouches ... [et al.] -- Oral session 5: power plant surveillance. The role of ex-vessel neutron dosimetry in reactor vessel surveillance in South Korea / B.-C. Kim ... [et al.]. Spanish RPV surveillance programmes: lessons learned and current activities / A. Ballesteros and X. Jardí. Atucha I nuclear power plant extended dosimetry and assessment / H. Blaumann ... [et al.]. Monitoring of radiation load of pressure vessels of Russian VVER in compliance with license amendments / G. Borodkin ... [et al.] -- Poster session 2: Test reactors, accelerators and advanced systems; cross sections, nuclear

  4. EPR TOOTH DOSIMETRY OF SNTS AREA INHABITANTS

    PubMed Central

    Sholom, Sergey; Desrosiers, Marc; Bouville, André; Luckyanov, Nicholas; Chumak, Vadim

    2009-01-01

    The determination of external dose to teeth of inhabitants of settlements near the Semipalatinsk Nuclear Test Site (SNTS) was conducted using the EPR dosimetry technique to assess radiation doses associated with exposure to radioactive fallout from the test site. In this study, tooth doses have been reconstructed for 103 persons with all studied teeth having been formed before the first nuclear test in 1949. Doses above those received from natural background radiation, termed “accident doses”, were found to lie in the range from zero to approximately 2 Gy, with one exception, a dose for one person from Semipalatinsk city was approximately 9 Gy. The variability of reconstructed doses within each of the settlements demonstrated heterogeneity of the deposited fallout as well as variations in lifestyle. The village mean external gamma doses for residents of nine[ settlements were in the range from a few tens of mGy to approximately 100 mGy. PMID:19590746

  5. EPR TOOTH DOSIMETRY OF SNTS AREA INHABITANTS.

    PubMed

    Sholom, Sergey; Desrosiers, Marc; Bouville, André; Luckyanov, Nicholas; Chumak, Vadim; Simon, Steven L

    2007-07-01

    The determination of external dose to teeth of inhabitants of settlements near the Semipalatinsk Nuclear Test Site (SNTS) was conducted using the EPR dosimetry technique to assess radiation doses associated with exposure to radioactive fallout from the test site. In this study, tooth doses have been reconstructed for 103 persons with all studied teeth having been formed before the first nuclear test in 1949. Doses above those received from natural background radiation, termed "accident doses", were found to lie in the range from zero to approximately 2 Gy, with one exception, a dose for one person from Semipalatinsk city was approximately 9 Gy. The variability of reconstructed doses within each of the settlements demonstrated heterogeneity of the deposited fallout as well as variations in lifestyle. The village mean external gamma doses for residents of nine[ settlements were in the range from a few tens of mGy to approximately 100 mGy.

  6. Study of constraints in using household NaCl salt for retrospective dosimetry

    NASA Astrophysics Data System (ADS)

    Elashmawy, M.

    2018-05-01

    Thermoluminescence (TL) characteristics of 5 different household NaCl salts and one analytical salt were determined to investigate the possible factors that affect the reliability of using household salt for retrospective dosimetry. Salts' TL sensitivities were found to be particle-size dependent and approached saturation at the largest size, whereas for salts that have the same particle size, the TL sensitivity depended on their origin. TL dependence on the particle size interprets significant variations in TL response reported in the literature for the same salt patch. The first TL readout indicated that all salts have similar glow curves with one distinctive peak. Typical second TL readout at two different doses showed a dramatic decrease in TL sensitivity associated with a significant change in the glow curve structure possessing two prominent peaks. Glow curve deconvolution (GCD) of the first TL readout for all salts yielded 6 individual glow peaks of first-order kinetics, whereas in GCD of second TL readouts, 5 individual glow peaks of second-order kinetics were obtained. Similarities in the glow curve structures of the first and second TL readouts suggest that additives such as KIO3 and MgCO3 have no effect on the TL process. Fading effect was evaluated for the salt of highest TL sensitivity, and it was found that the integral TL intensity decreased gradually and lost 40% of its initial value over 2 weeks, after which it remained constant. Results conclude that a household salt cannot be used for retrospective dosimetry without considering certain constraints such as the salt's origin and particle size. Furthermore, preparedness for radiological accidents and accurate dose reconstructions require that most of the commonly distributed household salt brands should be calibrated in advance and stored in a repository to be recalled in case of accidents.

  7. Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density.

    PubMed

    Marroquin, Elsa Y León; Herrera González, José A; Camacho López, Miguel A; Barajas, José E Villarreal; García-Garduño, Olivia A

    2016-09-08

    Radiochromic film has become an important tool to verify dose distributions for intensity-modulated radiotherapy (IMRT) and quality assurance (QA) procedures. A new radiochromic film model, EBT3, has recently become available, whose composition and thickness of the sensitive layer are the same as those of previous EBT2 films. However, a matte polyester layer was added to EBT3 to prevent the formation of Newton's rings. Furthermore, the symmetrical design of EBT3 allows the user to eliminate side-orientation dependence. This film and the flatbed scanner, Epson Perfection V750, form a dosimetry system whose intrinsic characteristics were studied in this work. In addition, uncertainties associated with these intrinsic characteristics and the total uncertainty of the dosimetry system were determined. The analysis of the response of the radiochromic film (net optical density) and the fitting of the experimental data to a potential function yielded an uncertainty of 2.6%, 4.3%, and 4.1% for the red, green, and blue channels, respectively. In this work, the dosimetry system presents an uncertainty in resolving the dose of 1.8% for doses greater than 0.8 Gy and less than 6 Gy for red channel. The films irradiated between 0 and 120 Gy show differences in the response when scanned in portrait or landscape mode; less uncertainty was found when using the portrait mode. The response of the film depended on the position on the bed of the scanner, contributing an uncertainty of 2% for the red, 3% for the green, and 4.5% for the blue when placing the film around the center of the bed of scanner. Furthermore, the uniformity and reproducibility radiochromic film and reproducibility of the response of the scanner contribute less than 1% to the overall uncertainty in dose. Finally, the total dose uncertainty was 3.2%, 4.9%, and 5.2% for red, green, and blue channels, respectively. The above uncertainty values were obtained by mini-mizing the contribution to the total dose uncertainty

  8. Applicability of Glass Dosimeters for In-vivo Dosimetry in Brachytherapy

    NASA Astrophysics Data System (ADS)

    Moon, Sun Young; Son, Jaeman; Yoon, Myonggeun; Jeang, EunHee; Lim, Young Kyung; Chung, Weon Kyu; Kim, Dong Wook

    2018-06-01

    During brachytherapy, confirming the dose delivered is very important in order to prevent radiation-associated side effects. Therefore, we aimed to confirm the accuracy of dose delivery near the source by inserting glass dosimeters within the applicator. We created an alternative pelvic phantom with the same shape and internal structures as the usual patient. In addition, we created a tandem for insertion of the glass dosimeters and measured the dose near the source by inserting the glass dosimeters into the tandem and evaluating the accuracy of the dwell position and time through the dose near the source. Errors between the values obtained from the five glass dosimeters and the values from the treatment planning system were -6.27, -2.1, -4.18, 6.31, and -0.39%, respectively. The mean error was 3.85%. This value was acceptable considering that the error of the glass dosimeter itself is approximately 3%. Even though a complement of the applicator and the error calibration is required in order to apply this technique clinically, we believe that radiation accidents and overdoses can be prevented through in-vivo dosimetry using a glass dosimeter for brachytherapy.

  9. Modular telerobot control system for accident response

    NASA Astrophysics Data System (ADS)

    Anderson, Richard J. M.; Shirey, David L.

    1999-08-01

    The Accident Response Mobile Manipulator System (ARMMS) is a teleoperated emergency response vehicle that deploys two hydraulic manipulators, five cameras, and an array of sensors to the scene of an incident. It is operated from a remote base station that can be situated up to four kilometers away from the site. Recently, a modular telerobot control architecture called SMART was applied to ARMMS to improve the precision, safety, and operability of the manipulators on board. Using SMART, a prototype manipulator control system was developed in a couple of days, and an integrated working system was demonstrated within a couple of months. New capabilities such as camera-frame teleoperation, autonomous tool changeout and dual manipulator control have been incorporated. The final system incorporates twenty-two separate modules and implements seven different behavior modes. This paper describes the integration of SMART into the ARMMS system.

  10. Visualization of Traffic Accidents

    NASA Technical Reports Server (NTRS)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  11. Characteristics of Hydrogen Monitoring Systems for Severe Accident Management at a Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Petrosyan, V. G.; Yeghoyan, E. A.; Grigoryan, A. D.; Petrosyan, A. P.; Movsisyan, M. R.

    2018-02-01

    One of the main objectives of severe accident management at a nuclear power plant is to protect the integrity of the containment, for which the most serious threat is possible ignition of the generated hydrogen. There should be a monitoring system providing information support of NPP personnel, ensuring data on the current state of a containment gaseous environment and trends in its composition changes. Monitoring systems' requisite characteristics definition issues are considered by the example of a particular power unit. Major characteristics important for proper information support are discussed. Some features of progression of severe accident scenarios at considered power unit are described and a possible influence of the hydrogen concentration monitoring system performance on the information support reliability in a severe accident is analyzed. The analysis results show that the following technical characteristics of the combustible gas monitoring systems are important for the proper information support of NPP personnel in the event of a severe accident at a nuclear power plant: measured parameters, measuring ranges and errors, update rate, minimum detectable concentration of combustible gas, monitoring reference points, environmental qualification parameters of the system components. For NPP power units with WWER-440/270 (230) type reactors, which have a relatively small containment volume, the update period for measurement results is a critical characteristic of the containment combustible gas monitoring system, and the choice of monitoring reference points should be focused not so much on the definition of places of possible hydrogen pockets but rather on the definition of places of a possible combustible mixture formation. It may be necessary for the above-mentioned power units to include in the emergency operating procedures measures aimed at a timely heat removal reduction from the containment environment if there are signs of a severe accident phase

  12. THE MAYAK WORKER DOSIMETRY SYSTEM (MWDS-2013) FOR INTERNALLY DEPOSITED PLUTONIUM: AN OVERVIEW

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Birchall, A.; Vostrotin, V.; Puncher, M.

    The Mayak Worker Dosimetry System (MWDS-2013) is a system for interpreting measurement data from Mayak workers from both internal and external sources. This paper is concerned with the calculation of annual organ doses for Mayak workers exposed to plutonium aerosols, where the measurement data consists mainly of activity of plutonium in urine samples. The system utilises the latest biokinetic and dosimetric models, and unlike its predecessors, takes explicit account of uncertainties in both the measurement data and model parameters. The aim of this paper is to describe the complete MWDS-2013 system (including model parameter values and their uncertainties) and themore » methodology used (including all the relevant equations) and the assumptions made. Where necessary, supplementary papers which justify specific assumptions are cited.« less

  13. Optically stimulated luminescence dosimetry with gypsum wallboard (drywall).

    PubMed

    Thompson, Jeroen W; Burdette, Kevin E; Inrig, Elizabeth L; Dewitt, Regina; Mistry, Rajesh; Rink, W Jack; Boreham, Douglas R

    2010-09-01

    Gypsum wallboard (drywall) represents an attractive target for retrospective dosimetry by optically stimulated luminescence (OSL) in the event of a radiological accident or malicious use of nuclear material. In this study, wallboard is shown to display a radiation-induced luminescence signal (RIS) as well as a natural background signal (NS), which is comparable in intensity to the RIS. Excitation and emission spectra show that maximum luminescence intensity is obtained for stimulation with blue light-emitting diodes (470 nm) and for detection in the ultraviolet region (290-370 nm). It is necessary to decrease the optical stimulation power dramatically in order to adequately separate the RIS from the interfering background signal. The necessary protocols are developed for accurately measuring the absorbed dose as low as 500 mGy and demonstrate that the RIS decays logarithmically with storage time, with complete erasure expected within 1-4 d.

  14. Wet weather highway accident analysis and skid resistance data management system (volume II : user's manual).

    DOT National Transportation Integrated Search

    1992-06-01

    The objectives and scope of this research are to establish an effective methodology for wet weather accident analysis and to develop a database management system to facilitate information processing and storage for the accident analysis process, skid...

  15. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Su'ud, Zaki; Anshari, Rio

    2012-06-01

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  16. Development of a portable graphite calorimeter for radiation dosimetry.

    PubMed

    Sakama, Makoto; Kanai, Tatsuaki; Fukumura, Akifumi

    2008-01-01

    We developed and performance-tested a portable graphite calorimeter designed to measure the absolute dosimetry of various beams including heavy-ion beams, based on a flexible and convenient means of measurement. This measurement system is fully remote-controlled by the GPIB system. This system uses a digital PID (Proportional, Integral, Derivative) control method based on the LabVIEW software. It was possible to attain stable conditions in a shorter time by this system. The standard deviation of the measurements using the calorimeter was 0.79% at a dose rate of 0.8 Gy/min in 17 calorimeter runs for a (60)Co photon beam. The overall uncertainties for the absorbed dose to graphite and water of the (60)Co photon beam using the developed calorimeter were 0.89% and 1.35%, respectively. Estimations of the correction factors due to vacuum gaps, impurities in the core, the dose gradient and the radiation profile were included in the uncertainties. The absorbed doses to graphite and water irradiated by the (60)Co photon beam were compared with dosimetry measurements obtained using three ionization chambers. The absorbed doses to graphite and water estimated by the two dosimetry methods agreed within 0.1% and 0.3%, respectively.

  17. Systems thinking, the Swiss Cheese Model and accident analysis: a comparative systemic analysis of the Grayrigg train derailment using the ATSB, AcciMap and STAMP models.

    PubMed

    Underwood, Peter; Waterson, Patrick

    2014-07-01

    The Swiss Cheese Model (SCM) is the most popular accident causation model and is widely used throughout various industries. A debate exists in the research literature over whether the SCM remains a viable tool for accident analysis. Critics of the model suggest that it provides a sequential, oversimplified view of accidents. Conversely, proponents suggest that it embodies the concepts of systems theory, as per the contemporary systemic analysis techniques. The aim of this paper was to consider whether the SCM can provide a systems thinking approach and remain a viable option for accident analysis. To achieve this, the train derailment at Grayrigg was analysed with an SCM-based model (the ATSB accident investigation model) and two systemic accident analysis methods (AcciMap and STAMP). The analysis outputs and usage of the techniques were compared. The findings of the study showed that each model applied the systems thinking approach. However, the ATSB model and AcciMap graphically presented their findings in a more succinct manner, whereas STAMP more clearly embodied the concepts of systems theory. The study suggests that, whilst the selection of an analysis method is subject to trade-offs that practitioners and researchers must make, the SCM remains a viable model for accident analysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. A system of safety management practices and worker engagement for reducing and preventing accidents: an empirical and theoretical investigation.

    PubMed

    Wachter, Jan K; Yorio, Patrick L

    2014-07-01

    The overall research objective was to theoretically and empirically develop the ideas around a system of safety management practices (ten practices were elaborated), to test their relationship with objective safety statistics (such as accident rates), and to explore how these practices work to achieve positive safety results (accident prevention) through worker engagement. Data were collected using safety manager, supervisor and employee surveys designed to assess and link safety management system practices, employee perceptions resulting from existing practices, and safety performance outcomes. Results indicate the following: there is a significant negative relationship between the presence of ten individual safety management practices, as well as the composite of these practices, with accident rates; there is a significant negative relationship between the level of safety-focused worker emotional and cognitive engagement with accident rates; safety management systems and worker engagement levels can be used individually to predict accident rates; safety management systems can be used to predict worker engagement levels; and worker engagement levels act as mediators between the safety management system and safety performance outcomes (such as accident rates). Even though the presence of safety management system practices is linked with incident reduction and may represent a necessary first-step in accident prevention, safety performance may also depend on mediation by safety-focused cognitive and emotional engagement by workers. Thus, when organizations invest in a safety management system approach to reducing/preventing accidents and improving safety performance, they should also be concerned about winning over the minds and hearts of their workers through human performance-based safety management systems designed to promote and enhance worker engagement. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Perineal template techniques for interstitial implantation of gynecological cancers using the Paris system of dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Leung, S.

    1990-09-01

    Since 1984, perineal template/needle techniques for interstitial implantation of gynecologic cancer-cervix, vagina, vulva-have been developed at the Peter MacCallum Cancer Institute. The Paris System of dosimetry has been used resulting in greater dose homogeneity, fewer needles and radioactive sources and considerable simplification and ease of implantation compared with comparable techniques developed in the United States. Principles and techniques of implantation are described in detail.

  20. Comparison of intraoperative dosimetric implant representation with postimplant dosimetry in patients receiving prostate brachytherapy.

    PubMed

    Stone, Nelson N; Hong, Suzanne; Lo, Yeh-Chi; Howard, Victor; Stock, Richard G

    2003-01-01

    To compare the results of intraoperative dosimetry with those of CT-based postimplant dosimetry in patients undergoing prostate seed implantation. Seventy-seven patients with T1-T3 prostate cancer received an ultrasound-guided permanent seed implant (36 received (125)I, 7 (103)Pd, and 34 a partial (103)Pd implant plus external beam radiation therapy). The implantation was augmented with an intraoperative dosimetric planning system. After the peripheral needles were placed, 5-mm axial images were acquired into the treatment planning system. Soft tissue structures (prostate, urethra, and rectum) were contoured, and exact needle positions were registered. Seeds were placed with an applicator, and their positions were entered into the planning system. The dose distributions for the implant were calculated after interior needle and seed placement. Postimplant dosimetry was performed 1 month later on the basis of CT imaging. Prostate and urethral doses were compared, by using paired t tests, for the real-time dosimetry in the operating room (OR) and the postimplant dosimetry. The mean preimplant prostate volume was 39.8 cm(3), the postneedle planning volume was 41.5 cm(3) (p<0.001), and the 1-month CT volume was 43.6 cm(3) (p<0.001). The mean difference between the OR dose received by 90% of the prostate (D(90)) and the CT D(90) was 3.4% (95% confidence interval, 2.5-6.6%; p=0.034). The mean dose to 30% of the urethra was 120% of prescription in the OR and 138% on CT. The mean difference was 18% (95% confidence interval, 13-24%; p<0.001). Although small differences exist between the OR and CT dosimetry results, these data suggest that this intraoperative implant dosimetric representation system provides a close match to the actual delivered doses. These data support the use of this system to modify the implant during surgery to achieve more consistent dosimetry results.

  1. AFRRI Neutron Dosimetry and Radiobiology Conference

    DTIC Science & Technology

    1988-11-09

    Neutron Dosimetry and Radiobiology 8 - 9 November 1988 Sponsored by Defense Nuclear Agency ARMED FORCES RADIOBIOLOGY RESEARCH INSTITUTE...neutron radiation is less amenable to amelioration by chemical radioprotectants and more difficult to assess by means of physical dosimetry . These...neutron dosimetry and radiobiology we have witnessed in the past several years,could not have been possible without the sustained efforts of many

  2. A complete dosimetry experimental program in support to the core characterization and to the power calibration of the CABRI reactor. A complete dosimetry experimental program in support of the core characterization and of the power calibration of the CABRI reactor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rodiac, F.; Hudelot, JP.; Lecerf, J.

    CABRI is an experimental pulse reactor operated by CEA at the Cadarache research center. Since 1978 the experimental programs have aimed at studying the fuel behavior under Reactivity Initiated Accident (RIA) conditions. Since 2003, it has been refurbished in order to be able to provide RIA and LOCA (Loss Of Coolant Accident) experiments in prototypical PWR conditions (155 bar, 300 deg. C). This project is part of a broader scope including an overall facility refurbishment and a safety review. The global modification is conducted by the CEA project team. It is funded by IRSN, which is conducting the CIP experimentalmore » program, in the framework of the OECD/NEA project CIP. It is financed in the framework of an international collaboration. During the reactor restart, commissioning tests are realized for all equipment, systems and circuits of the reactor. In particular neutronics and power commissioning tests will be performed respectively in 2015 and 2016. This paper focuses on the design of a complete and original dosimetry program that was built in support to the CABRI core characterization and to the power calibration. Each one of the above experimental goals will be fully described, as well as the target uncertainties and the forecasted experimental techniques and data treatment. (authors)« less

  3. WE-AB-BRB-08: Progress Towards a 2D OSL Dosimetry System Using Al2O3:C Films

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ahmed, M F; Yukihara, E; Schnell, E

    Purpose: To develop a 2D dosimetry system based on the optically stimulated luminescence (OSL) of Al{sub 2}O{sub 3}:C films for medical applications. Methods: A 2D laser scanning OSL reader was built for readout of newly developed Al2O3:C films (Landauer Inc.). An image reconstruction algorithm was developed to correct for inherent effects introduced by reader design and detector properties. The system was tested using irradiations with photon and carbon ion beams. A calibration was obtained using a 6 MV photon beam from clinical accelerator and the dose measurement precision was tested using a range of doses and different dose distributions (flatmore » field and wedge field). The dynamic range and performance of the system in the presence of large dose gradients was also tested using 430 MeV/u {sup 12}C single and multiple pencil beams. All irradiations were performed with Gafchromic EBT3 film for comparison. Results: Preliminary results demonstrate a near-linear OSL dose response to photon fields and the ability to measure dose in dose distributions such as flat field and wedge field. Tests using {sup 12}C pencil beam demonstrate ability to measure doses over four orders of magnitude. The dose profiles measured by the OSL film generally agreed well with that measured by the EBT3 film. The OSL image signal-to-noise ratio obtained in the current conditions require further improvement. On the other hand, EBT3 films had large uncertainties in the low dose region due to film-to-film or intra-film variation in the background. Conclusion: A 2D OSL dosimetry system was developed and initial tests have demonstrated a wide dynamic range as well as good agreement between the delivered and measured doses. The low background, wide dynamic range and wide range of linearity in dose response observed for the Al{sub 2}O{sub 3}:C OSL film can be beneficial for dosimetry in radiation therapy applications, especially for small field dosimetry. This work has been funded by Landauer

  4. Shared dosimetry error in epidemiological dose-response analyses

    DOE PAGES

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; ...

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takesmore » up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.« less

  5. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takesmore » up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. Use of these methods for several studies, including the Mayak Worker Cohort and the U.S. Atomic Veterans Study, is discussed.« less

  6. Accident insurance, sickness, and science: New Zealand's no-fault system.

    PubMed

    Dew, Kevin

    2002-01-01

    This article explores the process of seeking compensation for occupational illness under a no-fault accident insurance scheme. The author uses two case studies--firefighters who attended a fire at a chemical storage depot and timbermill workers who worked with pentachlorophenol--to illustrate how science can be used to deny compensation to sick and dying workers. The results of the studies suggest that a no-fault accident compensation scheme, considered to be a victory for workers, offers no guarantee of just outcomes for working people. And science can be co-opted and used to support business and state interests against workers; this ideological support is increasingly hidden behind the development of "objective" systems of assessing compensation claims.

  7. Automated accident detection at intersections.

    DOT National Transportation Integrated Search

    2004-03-01

    This research aims to provide a timely and accurate accident detection method at intersections, which is : very important for the Traffic Management System(TMS). This research uses acoustic signals to detect : accident at intersections. A system is c...

  8. Analysis on the Role of RSG-GAS Pool Cooling System during Partial Loss of Heat Sink Accident

    NASA Astrophysics Data System (ADS)

    Susyadi; Endiah, P. H.; Sukmanto, D.; Andi, S. E.; Syaiful, B.; Hendro, T.; Geni, R. S.

    2018-02-01

    RSG-GAS is a 30 MW reactor that is mostly used for radioisotope production and experimental activities. Recently, it is regularly operated at half of its capacity for efficiency reason. During an accident, especially loss of heat sink, the role of its pool cooling system is very important to dump decay heat. An analysis using single failure approach and partial modeling of RELAP5 performed by S. Dibyo, 2010 shows that there is no significant increase in the coolant temperature if this system is properly functioned. However lessons learned from the Fukushima accident revealed that an accident can happen due to multiple failures. Considering ageing of the reactor, in this research the role of pool cooling system is to be investigated for a partial loss of heat sink accident which is at the same time the protection system fails to scram the reactor when being operated at 15 MW. The purpose is to clarify the transient characteristics and the final state of the coolant temperature. The method used is by simulating the system in RELAP5 code. Calculation results shows the pool cooling systems reduce coolant temperature for about 1 K as compared without activating them. The result alsoreveals that when the reactor is being operated at half of its rated power, it is still in safe condition for a partial loss of heat sink accident without scram.

  9. [Automatic Extraction and Analysis of Dosimetry Data in Radiotherapy Plans].

    PubMed

    Song, Wei; Zhao, Di; Lu, Hong; Zhang, Biyun; Ma, Jun; Yu, Dahai

    To improve the efficiency and accuracy of extraction and analysis of dosimetry data in radiotherapy plans for a batch of patients. With the interface function provided in Matlab platform, a program was written to extract the dosimetry data exported from treatment planning system in DICOM RT format and exported the dose-volume data to an Excel file with the SPSS compatible format. This method was compared with manual operation for 14 gastric carcinoma patients to validate the efficiency and accuracy. The output Excel data were compatible with SPSS in format, the dosimetry data error for PTV dose interval of 90%-98%, PTV dose interval of 99%-106% and all OARs were -3.48E-5 ± 3.01E-5, -1.11E-3 ± 7.68E-4, -7.85E-5 ± 9.91E-5 respectively. Compared with manual operation, the time required was reduced from 5.3 h to 0.19 h and input error was reduced from 0.002 to 0. The automatic extraction of dosimetry data in DICOM RT format for batch patients, the SPSS compatible data exportation, quick analysis were achieved in this paper. The efficiency of clinical researches based on dosimetry data analysis of large number of patients will be improved with this methods.

  10. The Latin American Biological Dosimetry Network (LBDNet).

    PubMed

    García, O; Di Giorgio, M; Radl, A; Taja, M R; Sapienza, C E; Deminge, M M; Fernández Rearte, J; Stuck Oliveira, M; Valdivia, P; Lamadrid, A I; González, J E; Romero, I; Mandina, T; Guerrero-Carbajal, C; ArceoMaldonado, C; Cortina Ramírez, G E; Espinoza, M; Martínez-López, W; Di Tomasso, M

    2016-09-01

    Biological Dosimetry is a necessary support for national radiation protection programmes and emergency response schemes. The Latin American Biological Dosimetry Network (LBDNet) was formally founded in 2007 to provide early biological dosimetry assistance in case of radiation emergencies in the Latin American Region. Here are presented the main topics considered in the foundational document of the network, which comprise: mission, partners, concept of operation, including the mechanism to request support for biological dosimetry assistance in the region, and the network capabilities. The process for network activation and the role of the coordinating laboratory during biological dosimetry emergency response is also presented. This information is preceded by historical remarks on biological dosimetry cooperation in Latin America. A summary of the main experimental and practical results already obtained by the LBDNet is also included. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. The Self-Powered Detector Simulation `MATiSSe' Toolbox applied to SPNDs for severe accident monitoring in PWRs

    NASA Astrophysics Data System (ADS)

    Barbot, Loïc; Villard, Jean-François; Fourrez, Stéphane; Pichon, Laurent; Makil, Hamid

    2018-01-01

    In the framework of the French National Research Agency program on nuclear safety and radioprotection, the `DIstributed Sensing for COrium Monitoring and Safety' project aims at developing innovative instrumentation for corium monitoring in case of severe accident in a Pressurized Water nuclear Reactor. Among others, a new under-vessel instrumentation based on Self-Powered Neutron Detectors is developed using a numerical simulation toolbox, named `MATiSSe'. The CEA Instrumentation Sensors and Dosimetry Lab developed MATiSSe since 2010 for Self-Powered Neutron Detectors material selection and geometry design, as well as for their respective partial neutron and gamma sensitivity calculations. MATiSSe is based on a comprehensive model of neutron and gamma interactions which take place in Selfpowered neutron detector components using the MCNP6 Monte Carlo code. As member of the project consortium, the THERMOCOAX SAS Company is currently manufacturing some instrumented pole prototypes to be tested in 2017. The full severe accident monitoring equipment, including the standalone low current acquisition system, will be tested during a joined CEA-THERMOCOAX experimental campaign in some realistic irradiation conditions, in the Slovenian TRIGA Mark II research reactor.

  12. Dosimetry for Small and Nonstandard Fields

    NASA Astrophysics Data System (ADS)

    Junell, Stephanie L.

    The proposed small and non-standard field dosimetry protocol from the joint International Atomic Energy Agency (IAEA) and American Association of Physicist in Medicine working group introduces new reference field conditions for ionization chamber based reference dosimetry. Absorbed dose beam quality conversion factors (kQ factors) corresponding to this formalism were determined for three different models of ionization chambers: a Farmer-type ionization chamber, a thimble ionization chamber, and a small volume ionization chamber. Beam quality correction factor measurements were made in a specially developed cylindrical polymethyl methacrylate (PMMA) phantom and a water phantom using thermoluminescent dosimeters (TLDs) and alanine dosimeters to determine dose to water. The TLD system for absorbed dose to water determination in high energy photon and electron beams was fully characterized as part of this dissertation. The behavior of the beam quality correction factor was observed as it transfers the calibration coefficient from the University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) 60Co reference beam to the small field calibration conditions of the small field formalism. TLD-determined beam quality correction factors for the calibration conditions investigated ranged from 0.97 to 1.30 and had associated standard deviations from 1% to 3%. The alanine-determined beam quality correction factors ranged from 0.996 to 1.293. Volume averaging effects were observed with the Farmer-type ionization chamber in the small static field conditions. The proposed small and non-standard field dosimetry protocols new composite-field reference condition demonstrated its potential to reduce or remove ionization chamber volume dependancies, but the measured beam quality correction factors were not equal to the standard CoP's kQ, indicating a change in beam quality in the small and non-standard field dosimetry protocols new composite-field reference condition

  13. Anthropomorphic Phantom Radiation Dosimetry at the NATO Standard Reference Point at Aberdeen Proving Ground,

    DTIC Science & Technology

    1987-04-01

    and would still be well under 10(C. .% % p., I V a- E p - -12 - IABLE 8 (a) TLD results for phantom dosimetry - all values shown are measured charge...SAI. Conclusions The current DREO dosimetry system-consisting of bubble, CR39 and TLD dosimeters - has proven capable of producing meaningful results at...MC FILE CoPy’ Defence nationale 00 ANTHROPOMORPHIC PHANTOM RADIATION DOSIMETRY AT THE NATO STANDARD OREFERENCE POINT AT ABERDEEN PROVING GROUND by T

  14. Dosimetry in dentistry.

    PubMed

    Asha, M L; Chatterjee, Ingita; Patil, Preeti; Naveen, S

    2015-01-01

    The purpose of this paper was to review various dosimeters used in dentistry and the cumulative results of various studies done with various dosimeters. Several relevant PubMed indexed articles from 1999 to 2013 were electronically searched by typing "dosimeters", "dosimeters in dentistry", "properties of dosimeters", "thermoluminescent and optically stimulated dosimeters", "recent advancements in dosimetry in dentistry." The searches were limited to articles in English to prepare a concise review on dental dosimetry. Titles and abstracts were screened, and articles that fulfilled the criteria of use of dosimeters in dental applications were selected for a full-text reading. Article was divided into four groups: (1) Biological effects of radiation, (2) properties of dosimeters, (3) types of dosimeters and (4) results of various studies using different dosimeters. The present review on dosimetry based on various studies done with dosimeters revealed that, with the advent of radiographic technique the effective dose delivered is low. Therefore, selection of radiological technique plays an important role in dental dose delivery.

  15. GIS-based accident location and analysis system (GIS-ALAS) : project report : phase I

    DOT National Transportation Integrated Search

    1998-04-06

    This report summarizes progress made in Phase I of the geographic information system (GIS) based Accident Location and Analysis System (GIS-ALAS). The GIS-ALAS project builds on PC-ALAS, a locationally-referenced highway crash database query system d...

  16. Internal dosimetry technical basis manual

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1990-12-20

    The internal dosimetry program at the Savannah River Site (SRS) consists of radiation protection programs and activities used to detect and evaluate intakes of radioactive material by radiation workers. Examples of such programs are: air monitoring; surface contamination monitoring; personal contamination surveys; radiobioassay; and dose assessment. The objectives of the internal dosimetry program are to demonstrate that the workplace is under control and that workers are not being exposed to radioactive material, and to detect and assess inadvertent intakes in the workplace. The Savannah River Site Internal Dosimetry Technical Basis Manual (TBM) is intended to provide a technical and philosophicalmore » discussion of the radiobioassay and dose assessment aspects of the internal dosimetry program. Detailed information on air, surface, and personal contamination surveillance programs is not given in this manual except for how these programs interface with routine and special bioassay programs.« less

  17. Design and implementation of an identification system in construction site safety for proactive accident prevention.

    PubMed

    Yang, Huanjia; Chew, David A S; Wu, Weiwei; Zhou, Zhipeng; Li, Qiming

    2012-09-01

    Identifying accident precursors using real-time identity information has great potential to improve safety performance in construction industry, which is still suffering from day to day records of accident fatality and injury. Based on the requirements analysis for identifying precursor and the discussion of enabling technology solutions for acquiring and sharing real-time automatic identification information on construction site, this paper proposes an identification system design for proactive accident prevention to improve construction site safety. Firstly, a case study is conducted to analyze the automatic identification requirements for identifying accident precursors in construction site. Results show that it mainly consists of three aspects, namely access control, training and inspection information and operation authority. The system is then designed to fulfill these requirements based on ZigBee enabled wireless sensor network (WSN), radio frequency identification (RFID) technology and an integrated ZigBee RFID sensor network structure. At the same time, an information database is also designed and implemented, which includes 15 tables, 54 queries and several reports and forms. In the end, a demonstration system based on the proposed system design is developed as a proof of concept prototype. The contributions of this study include the requirement analysis and technical design of a real-time identity information tracking solution for proactive accident prevention on construction sites. The technical solution proposed in this paper has a significant importance in improving safety performance on construction sites. Moreover, this study can serve as a reference design for future system integrations where more functions, such as environment monitoring and location tracking, can be added. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Su'ud, Zaki; Anshari, Rio

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environmentmore » such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.« less

  19. Implementation of alanine/EPR as transfer dosimetry system in a radiotherapy audit programme in Belgium.

    PubMed

    Schaeken, B; Cuypers, R; Lelie, S; Schroeyers, W; Schreurs, S; Janssens, H; Verellen, D

    2011-04-01

    A measurement procedure based on alanine/electron paramagnetic resonance (EPR) dosimetry was implemented successfully providing simple, stable, and accurate dose-to-water (D(w)) measurements. The correspondence between alanine and ionization chamber measurements in reference conditions was excellent. Alanine/EMR dosimetry might be a valuable alternative to thermoluminescent (TLD) and ionization chamber based measuring procedures in radiotherapy audits. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  20. Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density

    PubMed Central

    Marroquin, Elsa Y. León; Herrera González, José A.; Camacho López, Miguel A.; Barajas, José E. Villarreal

    2016-01-01

    Radiochromic film has become an important tool to verify dose distributions for intensity‐modulated radiotherapy (IMRT) and quality assurance (QA) procedures. A new radiochromic film model, EBT3, has recently become available, whose composition and thickness of the sensitive layer are the same as those of previous EBT2 films. However, a matte polyester layer was added to EBT3 to prevent the formation of Newton's rings. Furthermore, the symmetrical design of EBT3 allows the user to eliminate side‐orientation dependence. This film and the flatbed scanner, Epson Perfection V750, form a dosimetry system whose intrinsic characteristics were studied in this work. In addition, uncertainties associated with these intrinsic characteristics and the total uncertainty of the dosimetry system were determined. The analysis of the response of the radiochromic film (net optical density) and the fitting of the experimental data to a potential function yielded an uncertainty of 2.6%, 4.3%, and 4.1% for the red, green, and blue channels, respectively. In this work, the dosimetry system presents an uncertainty in resolving the dose of 1.8% for doses greater than 0.8 Gy and less than 6 Gy for red channel. The films irradiated between 0 and 120 Gy show differences in the response when scanned in portrait or landscape mode; less uncertainty was found when using the portrait mode. The response of the film depended on the position on the bed of the scanner, contributing an uncertainty of 2% for the red, 3% for the green, and 4.5% for the blue when placing the film around the center of the bed of scanner. Furthermore, the uniformity and reproducibility radiochromic film and reproducibility of the response of the scanner contribute less than 1% to the overall uncertainty in dose. Finally, the total dose uncertainty was 3.2%, 4.9%, and 5.2% for red, green, and blue channels, respectively. The above uncertainty values were obtained by minimizing the contribution to the total dose

  1. Investigations on optimization of accident management measures following a station blackout accident in a VVER-1000 pressurized water reactor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tusheva, P.; Schaefer, F.; Kliem, S.

    2012-07-01

    The reactor safety issues are of primary importance for preserving the health of the population and ensuring no release of radioactivity and fission products into the environment. A part of the nuclear research focuses on improvement of the safety of existing nuclear power plants. Studies, research and efforts are a continuing process at improving the safety and reliability of existing and newly developed nuclear power plants at prevention of a core melt accident. Station blackout (loss of AC power supply) is one of the dominant accidents taken into consideration at performing accident analysis. In case of multiple failures of safetymore » systems it leads to a severe accident. To prevent an accident to turn into a severe one or to mitigate the consequences, accident management measures must be performed. The present paper outlines possibilities for application and optimization of accident management measures following a station blackout accident. Assessed is the behaviour of the nuclear power plant during a station blackout accident without accident management measures and with application of primary/secondary side oriented accident management measures. Discussed are the possibilities for operators ' intervention and the influence of the performed accident management measures on the course of the accident. Special attention has been paid to the effectiveness of the passive feeding and physical phenomena having an influence on the system behaviour. The performed simulations show that the effectiveness of the secondary side feeding procedure can be limited due to an early evaporation or flashing effects in the feed water system. The analyzed cases show that the effectiveness of the accident management measures strongly depends on the initiation criteria applied for depressurization of the reactor coolant system. (authors)« less

  2. Toward acquiring comprehensive radiosurgery field commissioning data using the PRESAGE®/ optical-CT 3D dosimetry system

    NASA Astrophysics Data System (ADS)

    Clift, Corey; Thomas, Andrew; Adamovics, John; Chang, Zheng; Das, Indra; Oldham, Mark

    2010-03-01

    Achieving accurate small field dosimetry is challenging. This study investigates the utility of a radiochromic plastic PRESAGE® read with optical-CT for the acquisition of radiosurgery field commissioning data from a Novalis Tx system with a high-definition multileaf collimator (HDMLC). Total scatter factors (Sc, p), beam profiles, and penumbrae were measured for five different radiosurgery fields (5, 10, 20, 30 and 40 mm) using a commercially available optical-CT scanner (OCTOPUS, MGS Research). The percent depth dose (PDD), beam profile and penumbra of the 10 mm field were also measured using a higher resolution in-house prototype CCD-based scanner. Gafchromic EBT® film was used for independent verification. Measurements of Sc, p made with PRESAGE® and film agreed with mini-ion chamber commissioning data to within 4% for every field (range 0.2-3.6% for PRESAGE®, and 1.6-3.6% for EBT). PDD, beam profile and penumbra measurements made with the two PRESAGE®/optical-CT systems and film showed good agreement with the high-resolution diode commissioning measurements with a competitive resolution (0.5 mm pixels). The in-house prototype optical-CT scanner allowed much finer resolution compared with previous applications of PRESAGE®. The advantages of the PRESAGE® system for small field dosimetry include 3D measurements, negligible volume averaging, directional insensitivity, an absence of beam perturbations, energy and dose rate independence.

  3. Toward acquiring comprehensive radiosurgery field commissioning data using the PRESAGE®/optical-CT 3D dosimetry system

    PubMed Central

    Clift, Corey; Thomas, Andrew; Adamovics, John; Chang, Zheng; Das, Indra; Oldham, Mark

    2010-01-01

    Achieving accurate small field dosimetry is challenging. This study investigates the utility of a radiochromic plastic PRESAGE® read with optical-CT for the acquisition of radiosurgery field commissioning data from a Novalis Tx system with a high-definition multileaf collimator (HDMLC). Total scatter factors (Sc, p), beam profiles, and penumbrae were measured for five different radiosurgery fields (5, 10, 20, 30 and 40 mm) using a commercially available optical-CT scanner (OCTOPUS, MGS Research). The percent depth dose (PDD), beam profile and penumbra of the 10 mm field were also measured using a higher resolution in-house prototype CCD-based scanner. Gafchromic EBT® film was used for independent verification. Measurements of Sc, p made with PRESAGE® and film agreed with mini-ion chamber commissioning data to within 4% for every field (range 0.2–3.6% for PRESAGE®, and 1.6–3.6% for EBT). PDD, beam profile and penumbra measurements made with the two PRESAGE®/optical-CT systems and film showed good agreement with the high-resolution diode commissioning measurements with a competitive resolution (0.5 mm pixels). The in-house prototype optical-CT scanner allowed much finer resolution compared with previous applications of PRESAGE®. The advantages of the PRESAGE® system for small field dosimetry include 3D measurements, negligible volume averaging, directional insensitivity, an absence of beam perturbations, energy and dose rate independence. PMID:20134082

  4. Experimental Procedures for Sensitive and Reproducible In Situ EPR Tooth Dosimetry

    PubMed Central

    Williams, Benjamin B.; Sucheta, Artur; Dong, Ruhong; Sakata, Yasuko; Iwasaki, Akinori; Burke, Gregory; Grinberg, Oleg; Lesniewski, Piotr; Kmiec, Maciej; Swartz, Harold M.

    2007-01-01

    In vivo electron paramagnetic resonance (EPR) tooth dosimetry provides a means for non-invasive retrospective assessment of personal radiation exposure. While there is a clear need for such capabilities following radiation accidents, the most pressing need for the development of this technology is the heightened likelihood of terrorist events or nuclear conflicts. This technique will enable such measurements to be made at the site of an incident, while the subject is present, to assist emergency personnel as they perform triage for the affected population. At Dartmouth Medical School this development is currently being tested with normal volunteers with irradiated teeth placed in their mouths and with patients who have undergone radiation therapy. Here we describe progress in practical procedures to provide accurate and reproducible in vivo dose estimates. PMID:18591989

  5. Developing a Minimum Data Set for an Information Management System to Study Traffic Accidents in Iran.

    PubMed

    Mohammadi, Ali; Ahmadi, Maryam; Gharagozlu, Alireza

    2016-03-01

    Each year, around 1.2 million people die in the road traffic incidents. Reducing traffic accidents requires an exact understanding of the risk factors associated with traffic patterns and behaviors. Properly analyzing these factors calls for a comprehensive system for collecting and processing accident data. The aim of this study was to develop a minimum data set (MDS) for an information management system to study traffic accidents in Iran. This descriptive, cross-sectional study was performed in 2014. Data were collected from the traffic police, trauma centers, medical emergency centers, and via the internet. The investigated resources for this study were forms, databases, and documents retrieved from the internet. Forms and databases were identical, and one sample of each was evaluated. The related internet-sourced data were evaluated in their entirety. Data were collected using three checklists. In order to arrive at a consensus about the data elements, the decision Delphi technique was applied using questionnaires. The content validity and reliability of the questionnaires were assessed by experts' opinions and the test-retest method, respectively. An (MDS) of a traffic accident information management system was assigned to three sections: a minimum data set for traffic police with six classes, including 118 data elements; a trauma center with five data classes, including 57 data elements; and a medical emergency center, with 11 classes, including 64 data elements. Planning for the prevention of traffic accidents requires standardized data. As the foundation for crash prevention efforts, existing standard data infrastructures present policymakers and government officials with a great opportunity to strengthen and integrate existing accident information systems to better track road traffic injuries and fatalities.

  6. Geographic Information System (GIS) capabilities in traffic accident information management: a qualitative approach.

    PubMed

    Ahmadi, Maryam; Valinejadi, Ali; Goodarzi, Afshin; Safari, Ameneh; Hemmat, Morteza; Majdabadi, Hesamedin Askari; Mohammadi, Ali

    2017-06-01

    Traffic accidents are one of the more important national and international issues, and their consequences are important for the political, economical, and social level in a country. Management of traffic accident information requires information systems with analytical and accessibility capabilities to spatial and descriptive data. The aim of this study was to determine the capabilities of a Geographic Information System (GIS) in management of traffic accident information. This qualitative cross-sectional study was performed in 2016. In the first step, GIS capabilities were identified via literature retrieved from the Internet and based on the included criteria. Review of the literature was performed until data saturation was reached; a form was used to extract the capabilities. In the second step, study population were hospital managers, police, emergency, statisticians, and IT experts in trauma, emergency and police centers. Sampling was purposive. Data was collected using a questionnaire based on the first step data; validity and reliability were determined by content validity and Cronbach's alpha of 75%. Data was analyzed using the decision Delphi technique. GIS capabilities were identified in ten categories and 64 sub-categories. Import and process of spatial and descriptive data and so, analysis of this data were the most important capabilities of GIS in traffic accident information management. Storing and retrieving of descriptive and spatial data, providing statistical analysis in table, chart and zoning format, management of bad structure issues, determining the cost effectiveness of the decisions and prioritizing their implementation were the most important capabilities of GIS which can be efficient in the management of traffic accident information.

  7. ISD3: a particokinetic model for predicting the combined effects of particle sedimentation, diffusion and dissolution on cellular dosimetry for in vitro systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thomas, Dennis G.; Smith, Jordan N.; Thrall, Brian D.

    The development of particokinetic models describing the delivery of insoluble or poorly soluble nanoparticles to cells in liquid cell culture systems has improved the basis for dose-response analysis, hazard ranking from high-throughput systems, and now allows for translation of exposures across in vitro and in vivo test systems. Complimentary particokinetic models that address processes controlling delivery of both particles and released ions to cells, and the influence of particle size changes from dissolution on particle delivery for cell-culture systems would help advance our understanding of the role of particles ion dosimetry on cellular toxicology. We developed ISD3, an extension ofmore » our previously published model for insoluble particles, by deriving a specific formulation of the Population Balance Equation for soluble particles. ISD3 describes the time, concentration and particle size dependent dissolution of particles, their delivery to cells, and the delivery and uptake of ions to cells in in vitro liquid test systems. The model is modular, and can be adapted by application of any empirical model of dissolution, alternative approaches to calculating sedimentation rates, and cellular uptake or treatment of boundary conditions. We apply the model to calculate the particle and ion dosimetry of nanosilver and silver ions in vitro after calibration of two empirical models, one for particle dissolution and one for ion uptake. The results demonstrate utility and accuracy of the ISD3 framework for dosimetry in these systems. Total media ion concentration, particle concentration and total cell-associated silver time-courses were well described by the model, across 2 concentrations of 20 and 110 nm particles. ISD3 was calibrated to dissolution data for 20 nm particles as a function of serum protein concentration, but successfully described the media and cell dosimetry time-course for both particles at all concentrations and time points. We also report the

  8. 48 CFR 52.236-13 - Accident Prevention.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Accident Prevention. 52.236-13 Section 52.236-13 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION....236-13 Accident Prevention. As prescribed in 36.513, insert the following clause: Accident Prevention...

  9. Unexplained overexposures on physical dosimetry reported by biological dosimetry.

    PubMed

    Montoro, A; Almonacid, M; Villaescusa, J I; Verdu, G

    2009-01-01

    The Medical Service of the Radiation Protection Service from the University Hospital La Fe (Valencia, Spain), carries out medical examinations of the workers occupationally exposed to ionising radiation. The Biological Dosimetry Laboratory is developing its activity since 2001. Up to now, the activities have been focused in performing biological dosimetry studies of Interventionists workers from La Fe Hospital. Recently, the Laboratory has been authorized by the Health Authority in the Valencian Community. Unexplained overexposures of workers and patients are also studied. Workers suspected of being overexposed to ionising radiation were referred for investigation by cytogenetic analysis. Two of these were from Hospitals of the Valencian Community and one belonged to an uranium mine from Portugal. Hospital workers had a physical dose by thermoluminiscence dosimeters (TLD) that exceeded the established limit. The worker of the uranium mine received a dose from a lost source of Cesium 137 with an activity of 170 mCi. All three cases showed normal values after the hematological analysis. Finally, the aim of this study consist to determine whether the dose showed by the dosimeter is reliable or not. In the case of workers that wore dosimeter, it is concluded that the doses measured by dosimeter are not corresponding to real doses. Hospital worker with a physical dose of 2.6 Sv and 0.269 Sv had an estimated absorbed dose by biological dosimetry of 0.076 Gy (0-0.165 Gy) and 0 Gy (0-0.089 Gy), respectively. In case of the mine worker an estimated absorbed dose of 0.073 Gy (0-0.159 Gy) was obtained by biological dosimetry. In all cases we used the odds ratio to present the results due to a very low frequency of observed aberrations [1].

  10. [The use of polymer gel dosimetry to measure dose distribution around metallic implants].

    PubMed

    Nagahata, Tomomasa; Yamaguchi, Hajime; Monzen, Hajime; Nishimura, Yasumasa

    2014-10-01

    A semi-solid polymer dosimetry system using agar was developed to measure the dose distribution close to metallic implants. Dosimetry of heterogeneous fields where electron density markedly varies is often problematic. This prompted us to develop a polymer gel dosimetry technique using agar to measure the dose distribution near substance boundaries. Varying the concentration of an oxygen scavenger (tetra-hydroxymethyl phosphonium chloride) showed the absorbed dose and transverse relaxation rate of the magnetic resonance signal to be linear between 3 and 12 Gy. Although a change in the dosimeter due to oxidization was observed in room air after 24 hours, no such effects were observed in the first 4 hours. The dose distribution around the metal implants was measured using agar dosimetry. The metals tested were a lead rod, a titanium hip joint, and a metallic stent. A maximum 30% dose increase was observed near the lead rod, but only a 3% increase in the absorbed dose was noted near the surface of the titanium hip joint and metallic stent. Semi-solid polymer dosimetry using agar thus appears to be a useful method for dosimetry around metallic substances.

  11. 41 CFR 101-39.407 - Accident records.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Accident records. 101-39...-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.4-Accidents and Claims § 101-39.407 Accident records. If GSA's records of vehicle accidents indicate that a particular activity has had an unusually high accident frequency...

  12. A smart phone-based pocket fall accident detection, positioning, and rescue system.

    PubMed

    Kau, Lih-Jen; Chen, Chih-Sheng

    2015-01-01

    We propose in this paper a novel algorithm as well as architecture for the fall accident detection and corresponding wide area rescue system based on a smart phone and the third generation (3G) networks. To realize the fall detection algorithm, the angles acquired by the electronic compass (ecompass) and the waveform sequence of the triaxial accelerometer on the smart phone are used as the system inputs. The acquired signals are then used to generate an ordered feature sequence and then examined in a sequential manner by the proposed cascade classifier for recognition purpose. Once the corresponding feature is verified by the classifier at current state, it can proceed to next state; otherwise, the system will reset to the initial state and wait for the appearance of another feature sequence. Once a fall accident event is detected, the user's position can be acquired by the global positioning system (GPS) or the assisted GPS, and sent to the rescue center via the 3G communication network so that the user can get medical help immediately. With the proposed cascaded classification architecture, the computational burden and power consumption issue on the smart phone system can be alleviated. Moreover, as we will see in the experiment that a distinguished fall accident detection accuracy up to 92% on the sensitivity and 99.75% on the specificity can be obtained when a set of 450 test actions in nine different kinds of activities are estimated by using the proposed cascaded classifier, which justifies the superiority of the proposed algorithm.

  13. The work programme of EURADOS on internal and external dosimetry.

    PubMed

    Rühm, W; Bottollier-Depois, J F; Gilvin, P; Harrison, R; Knežević, Ž; Lopez, M A; Tanner, R; Vargas, A; Woda, C

    2018-01-01

    Since the early 1980s, the European Radiation Dosimetry Group (EURADOS) has been maintaining a network of institutions interested in the dosimetry of ionising radiation. As of 2017, this network includes more than 70 institutions (research centres, dosimetry services, university institutes, etc.), and the EURADOS database lists more than 500 scientists who contribute to the EURADOS mission, which is to promote research and technical development in dosimetry and its implementation into practice, and to contribute to harmonisation of dosimetry in Europe and its conformance with international practices. The EURADOS working programme is organised into eight working groups dealing with environmental, computational, internal, and retrospective dosimetry; dosimetry in medical imaging; dosimetry in radiotherapy; dosimetry in high-energy radiation fields; and harmonisation of individual monitoring. Results are published as freely available EURADOS reports and in the peer-reviewed scientific literature. Moreover, EURADOS organises winter schools and training courses on various aspects relevant for radiation dosimetry, and formulates the strategic research needs in dosimetry important for Europe. This paper gives an overview on the most important EURADOS activities. More details can be found at www.eurados.org .

  14. Film dosimetry using a smart device camera: a feasibility study for point dose measurements

    NASA Astrophysics Data System (ADS)

    Aland, Trent; Jhala, Ekta; Kairn, Tanya; Trapp, Jamie

    2017-10-01

    In this work, a methodology for using a smartphone camera, in conjunction with a light-tight box operating in reflective transmission mode, is investigated as a proof of concept for use as a film dosimetry system. An imaging system was designed to allow the camera of a smartphone to be used as a pseudo densitometer. Ten pieces of Gafchromic EBT3 film were irradiated to doses up to 16.89 Gy and used to evaluate the effects of reproducibility and orientation, as well as the ability to create an accurate dose response curve for the smartphone based dosimetry system, using all three colour channels. Results were compared to a flatbed scanner system. Overall uncertainty was found to be best for the red channel with an uncertainty of 2.4% identified for film irradiated to 2.5 Gy and digitised using the smartphone system. This proof of concept exercise showed that although uncertainties still exceed a flatbed scanner system, the smartphone system may be useful for providing point dose measurements in situations where conventional flatbed scanners (or other dosimetry systems) are unavailable or unaffordable.

  15. Film dosimetry using a smart device camera: a feasibility study for point dose measurements.

    PubMed

    Aland, Trent; Jhala, Ekta; Kairn, Tanya; Trapp, Jamie

    2017-10-03

    In this work, a methodology for using a smartphone camera, in conjunction with a light-tight box operating in reflective transmission mode, is investigated as a proof of concept for use as a film dosimetry system. An imaging system was designed to allow the camera of a smartphone to be used as a pseudo densitometer. Ten pieces of Gafchromic EBT3 film were irradiated to doses up to 16.89 Gy and used to evaluate the effects of reproducibility and orientation, as well as the ability to create an accurate dose response curve for the smartphone based dosimetry system, using all three colour channels. Results were compared to a flatbed scanner system. Overall uncertainty was found to be best for the red channel with an uncertainty of 2.4% identified for film irradiated to 2.5 Gy and digitised using the smartphone system. This proof of concept exercise showed that although uncertainties still exceed a flatbed scanner system, the smartphone system may be useful for providing point dose measurements in situations where conventional flatbed scanners (or other dosimetry systems) are unavailable or unaffordable.

  16. Indonesian railway accidents--utilizing Human Factors Analysis and Classification System in determining potential contributing factors.

    PubMed

    Iridiastadi, Hardianto; Ikatrinasari, Zulfa Fitri

    2012-01-01

    The prevalence of Indonesian railway accidents has not been declining, with hundreds of fatalities reported in the past decade. As an effort to help the National Transportation Safety Committee (NTSC), this study was conducted that aimed at understanding factors that might have contributed to the accidents. Human Factors Analysis and Classification System (HFACS) was utilized for this purpose. A total of nine accident reports (provided by the Indonesian NTSC) involving fatalities were studied using the technique. Results of this study indicated 72 factors that were closely related to the accidents. Of these, roughly 22% were considered as operator acts while about 39% were related to preconditions for operator acts. Supervisory represented 14% of the factors, and the remaining (about 25%) were associated with organizational factors. It was concluded that, while train drivers indeed played an important role in the accidents, interventions solely directed toward train drivers may not be adequate. A more comprehensive approach in minimizing the accidents should be conducted that addresses all the four aspects of HFACS.

  17. Investigation of air cleaning system response to accident conditions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.

  18. Waste management facility accident analysis (WASTE ACC) system: software for analysis of waste management alternatives

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kohout, E.F.; Folga, S.; Mueller, C.

    1996-03-01

    This paper describes the Waste Management Facility Accident Analysis (WASTE{underscore}ACC) software, which was developed at Argonne National Laboratory (ANL) to support the US Department of Energy`s (DOE`s) Waste Management (WM) Programmatic Environmental Impact Statement (PEIS). WASTE{underscore}ACC is a decision support and database system that is compatible with Microsoft{reg_sign} Windows{trademark}. It assesses potential atmospheric releases from accidents at waste management facilities. The software provides the user with an easy-to-use tool to determine the risk-dominant accident sequences for the many possible combinations of process technologies, waste and facility types, and alternative cases described in the WM PEIS. In addition, its structure willmore » allow additional alternative cases and assumptions to be tested as part of the future DOE programmatic decision-making process. The WASTE{underscore}ACC system demonstrates one approach to performing a generic, systemwide evaluation of accident risks at waste management facilities. The advantages of WASTE{underscore}ACC are threefold. First, the software gets waste volume and radiological profile data that were used to perform other WM PEIS-related analyses directly from the WASTE{underscore}MGMT system. Second, the system allows for a consistent analysis across all sites and waste streams, which enables decision makers to understand more fully the trade-offs among various policy options and scenarios. Third, the system is easy to operate; even complex scenario runs are completed within minutes.« less

  19. Developing a Minimum Data Set for an Information Management System to Study Traffic Accidents in Iran

    PubMed Central

    Mohammadi, Ali; Ahmadi, Maryam; Gharagozlu, Alireza

    2016-01-01

    Background: Each year, around 1.2 million people die in the road traffic incidents. Reducing traffic accidents requires an exact understanding of the risk factors associated with traffic patterns and behaviors. Properly analyzing these factors calls for a comprehensive system for collecting and processing accident data. Objectives: The aim of this study was to develop a minimum data set (MDS) for an information management system to study traffic accidents in Iran. Materials and Methods: This descriptive, cross-sectional study was performed in 2014. Data were collected from the traffic police, trauma centers, medical emergency centers, and via the internet. The investigated resources for this study were forms, databases, and documents retrieved from the internet. Forms and databases were identical, and one sample of each was evaluated. The related internet-sourced data were evaluated in their entirety. Data were collected using three checklists. In order to arrive at a consensus about the data elements, the decision Delphi technique was applied using questionnaires. The content validity and reliability of the questionnaires were assessed by experts’ opinions and the test-retest method, respectively. Results: An (MDS) of a traffic accident information management system was assigned to three sections: a minimum data set for traffic police with six classes, including 118 data elements; a trauma center with five data classes, including 57 data elements; and a medical emergency center, with 11 classes, including 64 data elements. Conclusions: Planning for the prevention of traffic accidents requires standardized data. As the foundation for crash prevention efforts, existing standard data infrastructures present policymakers and government officials with a great opportunity to strengthen and integrate existing accident information systems to better track road traffic injuries and fatalities. PMID:27247791

  20. Manned space flight nuclear system safety. Volume 3: Reactor system preliminary nuclear safety analysis. Part 2: Accident Model Document (AMD)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Accident Model Document is one of three documents of the Preliminary Safety Analysis Report (PSAR) - Reactor System as applied to a Space Base Program. Potential terrestrial nuclear hazards involving the zirconium hydride reactor-Brayton power module are identified for all phases of the Space Base program. The accidents/events that give rise to the hazards are defined and abort sequence trees are developed to determine the sequence of events leading to the hazard and the associated probabilities of occurence. Source terms are calculated to determine the magnitude of the hazards. The above data is used in the mission accident analysis to determine the most probable and significant accidents/events in each mission phase. The only significant hazards during the prelaunch and launch ascent phases of the mission are those which arise form criticality accidents. Fission product inventories during this time period were found to be very low due to very limited low power acceptance testing.

  1. Geographic Information System (GIS) capabilities in traffic accident information management: a qualitative approach

    PubMed Central

    Ahmadi, Maryam; Valinejadi, Ali; Goodarzi, Afshin; Safari, Ameneh; Hemmat, Morteza; Majdabadi, Hesamedin Askari; Mohammadi, Ali

    2017-01-01

    Background Traffic accidents are one of the more important national and international issues, and their consequences are important for the political, economical, and social level in a country. Management of traffic accident information requires information systems with analytical and accessibility capabilities to spatial and descriptive data. Objective The aim of this study was to determine the capabilities of a Geographic Information System (GIS) in management of traffic accident information. Methods This qualitative cross-sectional study was performed in 2016. In the first step, GIS capabilities were identified via literature retrieved from the Internet and based on the included criteria. Review of the literature was performed until data saturation was reached; a form was used to extract the capabilities. In the second step, study population were hospital managers, police, emergency, statisticians, and IT experts in trauma, emergency and police centers. Sampling was purposive. Data was collected using a questionnaire based on the first step data; validity and reliability were determined by content validity and Cronbach’s alpha of 75%. Data was analyzed using the decision Delphi technique. Results GIS capabilities were identified in ten categories and 64 sub-categories. Import and process of spatial and descriptive data and so, analysis of this data were the most important capabilities of GIS in traffic accident information management. Conclusion Storing and retrieving of descriptive and spatial data, providing statistical analysis in table, chart and zoning format, management of bad structure issues, determining the cost effectiveness of the decisions and prioritizing their implementation were the most important capabilities of GIS which can be efficient in the management of traffic accident information. PMID:28848627

  2. TL dosimetry for quality control of CR mammography imaging systems

    NASA Astrophysics Data System (ADS)

    Gaona, E.; Nieto, J. A.; Góngora, J. A. I. D.; Arreola, M.; Enríquez, J. G. F.

    The aim of this work is to estimate the average glandular dose with thermoluminescent (TL) dosimetry and comparison with quality imaging in computed radiography (CR) mammography. For a measuring dose, the Food and Drug Administration (FDA) and the American College of Radiology (ACR) use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, full field digital mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium flourohalideE We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated X-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose greater than 3.0 mGy without demonstrating improved image quality. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement for X-rays with a HVL (0.35-0.38 mmAl) and kVp (24-26) used in quality control procedures with ACR Mammography Accreditation Phantom.

  3. Air core detectors for Cerenkov-free scintillation dosimetry of brachytherapy β-sources.

    PubMed

    Eichmann, Marion; Thomann, Benedikt

    2017-09-01

    Plastic scintillation detectors are used for dosimetry in small radiation fields with high dose gradients, e.g., provided by β-emitting sources like 106 Ru/ 106 Rh eye plaques. A drawback is a background signal caused by Cerenkov radiation generated by electrons passing the optical fibers (light guides) of this dosimetry system. Common approaches to correct for the Cerenkov signal are influenced by uncertainties resulting from detector positioning and calibration procedures. A different approach to avoid any correction procedure is to suppress the Cerenkov signal by replacing the solid core optical fiber with an air core light guide, previously shown for external beam therapy. In this study, the air core concept is modified and applied to the requirements of dosimetry in brachytherapy, proving its usability for measuring water energy doses in small radiation fields. Three air core detectors with different air core lengths are constructed and their performance in dosimetry for brachytherapy β-sources is compared with a standard two-fiber system, which uses a second fiber for Cerenkov correction. The detector systems are calibrated with a 90 Sr/ 90 Y secondary standard and tested for their angular dependence as well as their performance in depth dose measurements of 106 Ru/ 106 Rh sources. The signal loss relative to the standard detector increases with increasing air core length to a maximum value of 58.3%. At the same time, however, the percentage amount of Cerenkov light in the total signal is reduced from at least 12.1% to a value below 1.1%. There is a linear correlation between induced dose and measured signal current. The air core detectors determine the dose rates for 106 Ru/ 106 Rh sources without any form of correction for the Cerenkov signal. The air core detectors show advantages over the standard two-fiber system especially when measuring in radiation fields with high dose gradients. They can be used as simple one-fiber systems and allow for an almost

  4. Evaluation of a lithium formate EPR dosimetry system for dose measurements around {sup 192}Ir brachytherapy sources

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Antonovic, Laura; Gustafsson, Haakan; Alm Carlsson, Gudrun

    2009-06-15

    A dosimetry system using lithium formate monohydrate (HCO{sub 2}Li{center_dot}H{sub 2}O) as detector material and electron paramagnetic resonance (EPR) spectroscopy for readout has been used to measure absorbed dose distributions around clinical {sup 192}Ir sources. Cylindrical tablets with diameter of 4.5 mm, height of 4.8 mm, and density of 1.26 g/cm{sup 3} were manufactured. Homogeneity test and calibration of the dosimeters were performed in a 6 MV photon beam. {sup 192}Ir irradiations were performed in a PMMA phantom using two different source models, the GammaMed Plus HDR and the microSelectron PDR-v1 model. Measured absorbed doses to water in the PMMA phantommore » were converted to the corresponding absorbed doses to water in water phantoms of dimensions used by the treatment planning systems (TPSs) using correction factors explicitly derived for this experiment. Experimentally determined absorbed doses agreed with the absorbed doses to water calculated by the TPS to within {+-}2.9%. Relative standard uncertainties in the experimentally determined absorbed doses were estimated to be within the range of 1.7%-1.3% depending on the radial distance from the source, the type of source (HDR or PDR), and the particular absorbed doses used. This work shows that a lithium formate dosimetry system is well suited for measurements of absorbed dose to water around clinical HDR and PDR {sup 192}Ir sources. Being less energy dependent than the commonly used thermoluminescent lithium fluoride (LiF) dosimeters, lithium formate monohydrate dosimeters are well suited to measure absorbed doses in situations where the energy dependence cannot easily be accounted for such as in multiple-source irradiations to verify treatment plans. Their wide dynamic range and linear dose response over the dose interval of 0.2-1000 Gy make them suitable for measurements on sources of the strengths used in clinical applications. The dosimeter size needs, however, to be reduced for application

  5. SU-E-T-435: Development and Commissioning of a Complete System for In-Vivo Dosimetry and Range Verification in Proton Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Samuel, D; Testa, M; Park, Y

    Purpose: In-vivo dose and beam range verification in proton therapy could play significant roles in proton treatment validation and improvements. Invivo beam range verification, in particular, could enable new treatment techniques one of which, for example, could be the use of anterior fields for prostate treatment instead of opposed lateral fields as in current practice. We have developed and commissioned an integrated system with hardware, software and workflow protocols, to provide a complete solution, simultaneously for both in-vivo dosimetry and range verification for proton therapy. Methods: The system uses a matrix of diodes, up to 12 in total, but separablemore » into three groups for flexibility in application. A special amplifier was developed to capture extremely small signals from very low proton beam current. The software was developed within iMagX, a general platform for image processing in radiation therapy applications. The range determination exploits the inherent relationship between the internal range modulation clock of the proton therapy system and the radiological depth at the point of measurement. The commissioning of the system, for in-vivo dosimetry and for range verification was separately conducted using anthropomorphic phantom. EBT films and TLDs were used for dose comparisons and range scan of the beam distal fall-off was used as ground truth for range verification. Results: For in-vivo dose measurement, the results were in agreement with TLD and EBT films and were within 3% from treatment planning calculations. For range verification, a precision of 0.5mm is achieved in homogeneous phantoms, and a precision of 2mm for anthropomorphic pelvic phantom, except at points with significant range mixing. Conclusion: We completed the commissioning of our system for in-vivo dosimetry and range verification in proton therapy. The results suggest that the system is ready for clinical trials on patient.« less

  6. Tissue-equivalent TL sheet dosimetry system for X- and gamma-ray dose mapping.

    PubMed

    Nariyama, N; Konnai, A; Ohnishi, S; Odano, N; Yamaji, A; Ozasa, N; Ishikawa, Y

    2006-01-01

    To measure dose distribution for X- and gamma rays simply and accurately, a tissue-equivalent thermoluminescent (TL) sheet-type dosemeter and reader system were developed. The TL sheet is composed of LiF:Mg,Cu,P and ETFE polymer, and the thickness is 0.2 mm. For the TL reading, a square heating plate, 20 cm on each side, was developed, and the temperature distribution was measured with an infrared thermal imaging camera. As a result, linearity within 2% and the homogeneity within 3% were confirmed. The TL signal emitted is detected using a CCD camera and displayed as a spatial dose distribution. Irradiation using synchrotron radiation between 10 and 100 keV and (60)Co gamma rays showed that the TL sheet dosimetry system was promising for radiation dose mapping for various purposes.

  7. Characterization of a gated fiber-optic-coupled detector for application in clinical electron beam dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tanyi, James A.; Nitzling, Kevin D.; Lodwick, Camille J.

    2011-02-15

    Purpose: Assessment of the fundamental dosimetric characteristics of a novel gated fiber-optic-coupled dosimetry system for clinical electron beam irradiation. Methods: The response of fiber-optic-coupled dosimetry system to clinical electron beam, with nominal energy range of 6-20 MeV, was evaluated for reproducibility, linearity, and output dependence on dose rate, dose per pulse, energy, and field size. The validity of the detector system's response was assessed in correspondence with a reference ionization chamber. Results: The fiber-optic-coupled dosimetry system showed little dependence to dose rate variations (coefficient of variation {+-}0.37%) and dose per pulse changes (with 0.54% of reference chamber measurements). The reproducibilitymore » of the system was {+-}0.55% for dose fractions of {approx}100 cGy. Energy dependence was within {+-}1.67% relative to the reference ionization chamber for the 6-20 MeV nominal electron beam energy range. The system exhibited excellent linear response (R{sup 2}=1.000) compared to reference ionization chamber in the dose range of 1-1000 cGy. The output factors were within {+-}0.54% of the corresponding reference ionization chamber measurements. Conclusions: The dosimetric properties of the gated fiber-optic-coupled dosimetry system compare favorably to the corresponding reference ionization chamber measurements and show considerable potential for applications in clinical electron beam radiotherapy.« less

  8. Characterization of a fiber-coupled Al2O3:C luminescence dosimetry system for online in vivo dose verification during 192Ir brachytherapy.

    PubMed

    Andersen, Claus E; Nielsen, Søren Kynde; Greilich, Steffen; Helt-Hansen, Jakob; Lindegaard, Jacob Christian; Tanderup, Kari

    2009-03-01

    A prototype of a new dose-verification system has been developed to facilitate prevention and identification of dose delivery errors in remotely afterloaded brachytherapy. The system allows for automatic online in vivo dosimetry directly in the tumor region using small passive detector probes that fit into applicators such as standard needles or catheters. The system measures the absorbed dose rate (0.1 s time resolution) and total absorbed dose on the basis of radioluminescence (RL) and optically stimulated luminescence (OSL) from aluminum oxide crystals attached to optical fiber cables (1 mm outer diameter). The system was tested in the range from 0 to 4 Gy using a solid-water phantom, a Varian GammaMed Plus 192Ir PDR afterloader, and dosimetry probes inserted into stainless-steel brachytherapy needles. The calibrated system was found to be linear in the tested dose range. The reproducibility (one standard deviation) for RL and OSL measurements was 1.3%. The measured depth-dose profiles agreed well with the theoretical expectations computed with the EGSNRC Monte Carlo code, suggesting that the energy dependence for the dosimeter probes (relative to water) is less than 6% for source-to-probe distances in the range of 2-50 mm. Under certain conditions, the RL signal could be greatly disturbed by the so-called stem signal (i.e., unwanted light generated in the fiber cable upon irradiation). The OSL signal is not subject to this source of error. The tested system appears to be adequate for in vivo brachytherapy dosimetry.

  9. Review of Cytogenetic analysis of restoration workers for Fukushima Daiichi nuclear power station accident.

    PubMed

    Suto, Yumiko

    2016-09-01

    Japan faced with the nuclear accident of the Fukushima Daiichi Nuclear Power Station (NPS) caused by the combined disaster of the Great East Japan Earthquake and the subsequent tsunamis on 11 March 2011. National Institute of Radiological Sciences received all nuclear workers who were engaged in emergency response tasks at the NPS and suspected of being overexposed to acute radiation. Biological dosimetry by dicentric chromosome assay was helpful for medical triage and management of the workers. © World Health Organisation 2016. All rights reserved. The World Health Organization has granted Oxford University Press permission for the reproduction of this article.

  10. 48 CFR 836.513 - Accident prevention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Accident prevention. 836... CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 836.513 Accident prevention. The contracting officer must insert the clause at 852.236-87, Accident Prevention, in...

  11. 48 CFR 36.513 - Accident prevention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Accident prevention. 36... CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.513 Accident prevention. (a) The contracting officer shall insert the clause at 52.236-13, Accident Prevention, in...

  12. 48 CFR 36.513 - Accident prevention.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Accident prevention. 36... CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 36.513 Accident prevention. (a) The contracting officer shall insert the clause at 52.236-13, Accident Prevention, in...

  13. 48 CFR 836.513 - Accident prevention.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Accident prevention. 836... CATEGORIES OF CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 836.513 Accident prevention. The contracting officer must insert the clause at 852.236-87, Accident Prevention, in...

  14. Software tool for portal dosimetry research.

    PubMed

    Vial, P; Hunt, P; Greer, P B; Oliver, L; Baldock, C

    2008-09-01

    This paper describes a software tool developed for research into the use of an electronic portal imaging device (EPID) to verify dose for intensity modulated radiation therapy (IMRT) beams. A portal dose image prediction (PDIP) model that predicts the EPID response to IMRT beams has been implemented into a commercially available treatment planning system (TPS). The software tool described in this work was developed to modify the TPS PDIP model by incorporating correction factors into the predicted EPID image to account for the difference in EPID response to open beam radiation and multileaf collimator (MLC) transmitted radiation. The processes performed by the software tool include; i) read the MLC file and the PDIP from the TPS, ii) calculate the fraction of beam-on time that each point in the IMRT beam is shielded by MLC leaves, iii) interpolate correction factors from look-up tables, iv) create a corrected PDIP image from the product of the original PDIP and the correction factors and write the corrected image to file, v) display, analyse, and export various image datasets. The software tool was developed using the Microsoft Visual Studio.NET framework with the C# compiler. The operation of the software tool was validated. This software provided useful tools for EPID dosimetry research, and it is being utilised and further developed in ongoing EPID dosimetry and IMRT dosimetry projects.

  15. Managing Errors to Reduce Accidents in High Consequence Networked Information Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ganter, J.H.

    1999-02-01

    Computers have always helped to amplify and propagate errors made by people. The emergence of Networked Information Systems (NISs), which allow people and systems to quickly interact worldwide, has made understanding and minimizing human error more critical. This paper applies concepts from system safety to analyze how hazards (from hackers to power disruptions) penetrate NIS defenses (e.g., firewalls and operating systems) to cause accidents. Such events usually result from both active, easily identified failures and more subtle latent conditions that have resided in the system for long periods. Both active failures and latent conditions result from human errors. We classifymore » these into several types (slips, lapses, mistakes, etc.) and provide NIS examples of how they occur. Next we examine error minimization throughout the NIS lifecycle, from design through operation to reengineering. At each stage, steps can be taken to minimize the occurrence and effects of human errors. These include defensive design philosophies, architectural patterns to guide developers, and collaborative design that incorporates operational experiences and surprises into design efforts. We conclude by looking at three aspects of NISs that will cause continuing challenges in error and accident management: immaturity of the industry, limited risk perception, and resource tradeoffs.« less

  16. [Occupational accidents in an oil refinery in Brazil].

    PubMed

    Souza, Carlos Augusto Vaz de; Freitas, Carlos Machado de

    2002-10-01

    Work in oil refineries involves the risk of minor to major accidents. National data show the impact of accidents on this industry. A study was carried out to describe accident profile and evaluate the adequacy of accident reporting system. Data on all accidents reported in an oil refinery in the state of Rio de Janeiro for the year 1997 were organized and analyzed. The study population consisted of 153 injury cases, 83 hired and 69 contracted workers. The variables were: type of accident, operation mode and position of the worker injured. Among hired workers, minor accidents predominated (54.2%) and they occurred during regular operation activities (62.9%). Among contracted workers, there also predominated minor accidents (75.5%) in a higher percentage, but they occurred mainly during maintenance activities (96.8%). The study results showed that there is a predominance of accidents in lower hierarchy workers, and these accidents occur mainly during maintenance activities. There is a need to improve the company's accident reporting system and accident investigation procedures.

  17. A systemic analysis of South Korea Sewol ferry accident - Striking a balance between learning and accountability.

    PubMed

    Kee, Dohyung; Jun, Gyuchan Thomas; Waterson, Patrick; Haslam, Roger

    2017-03-01

    The South Korea Sewol ferry accident in April 2014 claimed the lives of over 300 passengers and led to criminal charges of 399 personnel concerned including imprisonment of 154 of them as of Oct 2014. Blame and punishment culture can be prevalent in a more hierarchical society like South Korea as shown in the aftermath of this disaster. This study aims to analyse the South Korea ferry accident using Rasmussen's risk management framework and the associated AcciMap technique and to propose recommendations drawn from an AcciMap-based focus group with systems safety experts. The data for the accident analysis were collected mainly from an interim investigation report by the Board of Audit and Inspection of Korea and major South Korean and foreign newspapers. The analysis showed that the accident was attributed to many contributing factors arising from front-line operators, management, regulators and government. It also showed how the multiple factors including economic, social and political pressures and individual workload contributed to the accident and how they affected each other. This AcciMap was presented to 27 safety researchers and experts at 'the legacy of Jens Rasmussen' symposium adjunct to ODAM2014. Their recommendations were captured through a focus group. The four main recommendations include forgive (no blame and punishment on individuals), analyse (socio-technical system-based), learn (from why things do not go wrong) and change (bottom-up safety culture and safety system management). The findings offer important insights into how this type of accident should be understood, analysed and the subsequent response. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. 48 CFR 852.236-87 - Accident prevention.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Accident prevention. 852... Accident prevention. As prescribed in 836.513, insert the following clause: Accident Prevention (SEP 1993....236-13, Accident Prevention. However, only the Contracting Officer may issue an order to stop all or...

  19. 48 CFR 852.236-87 - Accident prevention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Accident prevention. 852... Accident prevention. As prescribed in 836.513, insert the following clause: Accident Prevention (SEP 1993....236-13, Accident Prevention. However, only the Contracting Officer may issue an order to stop all or...

  20. [Analysis of accidents for magnetically induced displacement of the large ferromagnetic material in magnetic resonance systems].

    PubMed

    Yamatani, Yuya; Doi, Tsukasa; Ueyama, Tsuyoshi; Nishiki, Shigeo; Ogura, Akio; Kawamitsu, Hideaki; Tsuchihashi, Toshio; Okuaki, Tomoyuki; Matsuda, Tsuyoshi

    2013-01-01

    To improve magnetic resonance (MR) safety, we surveyed the accidents caused by large ferromagnetic materials brought into MR systems accidentally. We sent a questionnaire to 700 Japanese medical institutions and received 405 valid responses (58%). A total of 97 accidents in 77 institutions were observed and we analyzed them regarding incidental rate, the detail situation and environmental factors. The mean accident rate of each institute was 0.7/100,000 examinations, which was widely distributed (0-25.6/100,000) depending on the institute. In this survey, relatively small institutes with less than 500 beds tend to have these accidents more frequently (p<0.01). The institutes in which daily MR examination counts are more than 10 patients have fewer accidents than those with less than 10 daily examinations. The institutes with 6-10 MR examinations daily have significantly more accidents than that with more than 10 daily MR examinations (p<0.01). The main mental factors of the accidents were considered to be "prejudice" and "carelessness" but some advocate "ignorance." Though we could not find significant reduction in the institutes that have lectures and training for MR safety, we should continue lectures and training for MR safety to reduce accidents due to "ignorance."

  1. A comparison of two methods of in vivo dosimetry for a high energy neutron beam.

    PubMed

    Blake, S W; Bonnett, D E; Finch, J

    1990-06-01

    Two methods of in vivo dosimetry have been compared in a high energy neutron beam. These were activation dosimetry and thermoluminescence dosimetry (TLD). Their suitability was determined by comparison with estimates of total dose, obtained using a tissue equivalent ionization chamber. Measurements were made on the central axis and a profile of a 10 x 10 cm square field and also behind a shielding block in order to simulate conditions of clinical use. The TLD system was found to provide the best estimate of total dose.

  2. Real-time dosimetry in radiotherapy using tailored optical fibers

    NASA Astrophysics Data System (ADS)

    Rahman, A. K. M. Mizanur; Zubair, H. T.; Begum, Mahfuza; Abdul-Rashid, H. A.; Yusoff, Z.; Omar, Nasr Y. M.; Ung, N. M.; Mat-Sharif, K. A.; Bradley, D. A.

    2016-05-01

    Real-time dosimetry plays an important role for accurate patient-dose measurement during radiotherapy. A tiny piece of laboratory fabricated Ge-doped optical fiber has been investigated as a radioluminescence (RL) sensor for real-time dosimetry over the dose range from 1 Gy to 8 Gy under 6 MV photon beam by LINAC. Fiber-coupled software-based RL prototype system was used to assess essential dosimetric characteristics including dose response linearity, dose rate dependency, sensitivity, repeatability and output dependence on field sizes. The consistency level of RL photon counts versus dose rate was also compared with that of standard Al2O3:C chips. Sensitivity of Ge-doped fiber were found to be sufficiently sensitive for practical use and also provided linear dose responses for various dose rates from 100 cGy/min to 600 cGy/min using both 6 MV photon and 6 MeV electron beams. SEM-EDX analysis was performed to identify Ge-dopant concentration level within the optical fiber RL material. Accumulated doses were also estimated using simple integral technique and the error was found to be around less than 1% under dissimilar dose rates or repeat measurements. The evaluation of the Ge-doped optical fiber based RL dosimeter system indicates its potential in medical dosimetry.

  3. Human error and commercial aviation accidents: an analysis using the human factors analysis and classification system.

    PubMed

    Shappell, Scott; Detwiler, Cristy; Holcomb, Kali; Hackworth, Carla; Boquet, Albert; Wiegmann, Douglas A

    2007-04-01

    The aim of this study was to extend previous examinations of aviation accidents to include specific aircrew, environmental, supervisory, and organizational factors associated with two types of commercial aviation (air carrier and commuter/ on-demand) accidents using the Human Factors Analysis and Classification System (HFACS). HFACS is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research has shown that HFACS can be reliably used to identify human factors trends associated with military and general aviation accidents. Using data obtained from both the National Transportation Safety Board and the Federal Aviation Administration, 6 pilot-raters classified aircrew, supervisory, organizational, and environmental causal factors associated with 1020 commercial aviation accidents that occurred over a 13-year period. The majority of accident causal factors were attributed to aircrew and the environment, with decidedly fewer associated with supervisory and organizational causes. Comparisons were made between HFACS causal categories and traditional situational variables such as visual conditions, injury severity, and regional differences. These data will provide support for the continuation, modification, and/or development of interventions aimed at commercial aviation safety. HFACS provides a tool for assessing human factors associated with accidents and incidents.

  4. Biological dosimetry of ionizing radiation: Evaluation of the dose with cytogenetic methodologies by the construction of calibration curves

    NASA Astrophysics Data System (ADS)

    Zafiropoulos, Demetre; Facco, E.; Sarchiapone, Lucia

    2016-09-01

    In case of a radiation accident, it is well known that in the absence of physical dosimetry biological dosimetry based on cytogenetic methods is a unique tool to estimate individual absorbed dose. Moreover, even when physical dosimetry indicates an overexposure, scoring chromosome aberrations (dicentrics and rings) in human peripheral blood lymphocytes (PBLs) at metaphase is presently the most widely used method to confirm dose assessment. The analysis of dicentrics and rings in PBLs after Giemsa staining of metaphase cells is considered the most valid assay for radiation injury. This work shows that applying the fluorescence in situ hybridization (FISH) technique, using telomeric/centromeric peptide nucleic acid (PNA) probes in metaphase chromosomes for radiation dosimetry, could become a fast scoring, reliable and precise method for biological dosimetry after accidental radiation exposures. In both in vitro methods described above, lymphocyte stimulation is needed, and this limits the application in radiation emergency medicine where speed is considered to be a high priority. Using premature chromosome condensation (PCC), irradiated human PBLs (non-stimulated) were fused with mitotic CHO cells, and the yield of excess PCC fragments in Giemsa stained cells was scored. To score dicentrics and rings under PCC conditions, the necessary centromere and telomere detection of the chromosomes was obtained using FISH and specific PNA probes. Of course, a prerequisite for dose assessment in all cases is a dose-effect calibration curve. This work illustrates the various methods used; dose response calibration curves, with 95% confidence limits used to estimate dose uncertainties, have been constructed for conventional metaphase analysis and FISH. We also compare the dose-response curve constructed after scoring of dicentrics and rings using PCC combined with FISH and PNA probes. Also reported are dose response curves showing scored dicentrics and rings per cell, combining

  5. Use of artificial intelligence in severe accident diagnosis for PWRs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Zheng; Okrent, D.; Kastenberg, W.E.

    1995-12-31

    A combination approach of an expert system and neural networks is used to implement a prototype severe accident diagnostic system which would monitor the progression of the severe accident and provide necessary plant status information to assist the plant staff in accident management during the accident. The station blackout accident in a pressurized water reactor (PWR) is used as the study case. The current phase of research focus is on distinguishing different primary system failure modes and following the accident transient before and up to vessel breach.

  6. 48 CFR 636.513 - Accident prevention.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Accident prevention. 636... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 636.513 Accident prevention. (a) In... contracting activities shall insert DOSAR 652.236-70, Accident Prevention, in lieu of FAR clause 52.236-13...

  7. 48 CFR 636.513 - Accident prevention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Accident prevention. 636... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 636.513 Accident prevention. (a) In... contracting activities shall insert DOSAR 652.236-70, Accident Prevention, in lieu of FAR clause 52.236-13...

  8. Physician-patient relationship and medical accident victim compensation: some insights into the French regulatory system.

    PubMed

    Ancelot, Lydie; Oros, Cornel

    2015-06-01

    Given the growing amount of medical litigation heard by courts, the 2002 Kouchner law in France has created the Office National d'Indemnisation des Accidents Médicaux (ONIAM), whose main aim is to encourage out-of-court settlements when a conflict between a physician and the victim of a medical accident occurs. More than 10 years after the implementation of this law, the statistics analysing its effectiveness are contradictory, which raises the question of the potential negative effects of the ONIAM on the compensation system. In order to address this question, the article analyses the impact of the ONIAM on the nature of settlement negotiations between the physician and the victim. Using a dynamic game within incomplete information, we develop a comparative analysis of two types of compensation systems in case of medical accidents: socialised financing granted by the ONIAM and private financing provided by the physician. We show that the ONIAM could encourage out-of-court settlements provided that the hypothesis of judicial error is relevant. On the contrary, in the case of a low probability of judicial errors, the ONIAM could be effective only for severe medical accidents.

  9. Retrospective dosimetry of Iodine-131 exposures using Iodine-129 and Caesium-137 inventories in soils--A critical evaluation of the consequences of the Chernobyl accident in parts of Northern Ukraine.

    PubMed

    Michel, R; Daraoui, A; Gorny, M; Jakob, D; Sachse, R; Romantschuk, L D; Alfimov, V; Synal, H-A

    2015-12-01

    The radiation exposure of thyroid glands due to (131)I as a consequence of the Chernobyl accident was investigated retrospectively based on (129)I and (137)Cs inventories in soils in Northern Ukraine. To this end, soil samples from 60 settlements were investigated for (129)I, (127)I, and (137)Cs by AMS, ICP-MS and gamma-spectrometry, respectively. Sampling was performed between 2004 und 2007. In those parts of Northern Ukraine investigated here the (129)I and (137)Cs inventories are well correlated, the variability of the individual (129)I/(137)Cs ratios being, however, high. Both the (129)I and (137)Cs inventories in the individual 5 samples for each settlement allowed estimating the uncertainties of the inventories due to the variability of the radionuclide deposition and consequently of the retrospective dosimetry. Thyroid equivalent doses were calculated from the (129)I and the (137)Cs inventories using aggregated dose coefficients for 5-year old and 10-year-old children as well as for adults. The highest thyroid equivalent doses (calculated from (129)I inventories) were calculated for Wladimirowka with 30 Gy for 5-years-old children and 7 Gy for adults. In 35 settlements of contamination zone II the geometric mean of the thyroid equivalent doses was 2.0 Gy for 5-years-old children with a geometric standard deviation (GSD) of 3.0. For adults the geometric mean was 0.47 Gy also with a GSD of 3.0. In more than 25 settlements of contamination zone III the geometric means were 0.82 Gy for 5-years old children with a GSD of 1.8 and 0.21 Gy for adults (GSD 1.8). For 45 settlements, the results of the retrospective dosimetry could be compared with thyroid equivalent doses calculated using time-integrated (131)I activities of thyroids which were measured in 1986. Thus, a critical evaluation of the results was possible which demonstrated the general feasibility of the method, but also the associated uncertainties and limitations. Copyright © 2015 Elsevier Ltd. All

  10. The Role of Trust and Interaction in Global Positioning System Related Accidents

    NASA Technical Reports Server (NTRS)

    Johnson, Chris W.; Shea, Christine; Holloway, C. Michael

    2008-01-01

    The Global Positioning System (GPS) uses a network of satellites to calculate the position of a receiver over time. This technology has revolutionized a wide range of safety-critical industries and leisure applications. These systems provide diverse benefits; supplementing the users existing navigation skills and reducing the uncertainty that often characterizes many route planning tasks. GPS applications can also help to reduce workload by automating tasks that would otherwise require finite cognitive and perceptual resources. However, the operation of these systems has been identified as a contributory factor in a range of recent accidents. Users often come to rely on GPS applications and, therefore, fail to notice when they develop faults or when errors occur in the other systems that use the data from these systems. Further accidents can stem from the over confidence that arises when users assume automated warnings will be issued when they stray from an intended route. Unless greater attention is paid to the role of trust and interaction in GPS applications then there is a danger that we will see an increasing number of these failures as positioning technologies become integral in the functioning of increasing numbers of applications.

  11. Profile of an accident flying squad.

    PubMed

    Little, K

    1972-09-30

    An analysis of 184 accident flying squad calls and of 280 patients injured in road accidents and treated by a flying squad based on an accident department inclusive from 1967 to 1971 has shown that such a service can provide an efficient system without disrupting the routine work of the hospital.

  12. Traffic accidents on expressways: new threat to China.

    PubMed

    Zhao, Jinbao; Deng, Wei

    2012-01-01

    As China is building one of the largest expressway systems in the world, expressway safety problems have become serious concerns to China. This article analyzed the trends in expressway accidents in China from 1995 to 2010 and examined the characteristics of these accidents. Expressway accident data were obtained from the Annual Report for Road Traffic Accidents published by the Ministry of Public Security of China. Expressway mileage data were obtained from the National Statistics Yearbook published by the National Bureau of Statistics of China. Descriptive statistical analyses were conducted based on these data. Expressway deaths increased by 10.2-fold from 616 persons in 1995 to 6300 persons in 2010, and the average annual increase was 17.9 percent over the past 15 years, and the overall other road traffic deaths was -0.33 percent. China's expressway mileage accounted for only 1.85 percent of highway mileage driven in 2010, but expressway deaths made up 13.54 percent of highway traffic deaths. The average annual accident lethality rate [accident deaths/(accident deaths + accident injuries)] for China's expressways was 27.76 percent during the period 1995 to 2010, which was 1.33 times higher than the accident lethality rate of highway traffic accidents. China's government should pay attention to expressway construction and safety interventions during the rapid development period of expressways. Related causes, such as geographic patterns, speeding, weather conditions, and traffic flow composition, need to be studied in the near future. An effective and scientific expressway safety management services system, composed of a speed monitoring system, warning system, and emergency rescue system, should be established in developed and underdeveloped provinces in China to improve safety on expressway.

  13. National accident sampling system sample design, phases 2 and 3 : executive summary

    DOT National Transportation Integrated Search

    1979-11-01

    This report describes the Phase 2 and 3 sample design for the : National Accident Sampling System (NASS). It recommends a procedure : for the first-stage selection of Primary Sampling Units (PSU's) and : the second-stage design for the selection of a...

  14. Hanford internal dosimetry program manual

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carbaugh, E.H.; Sula, M.J.; Bihl, D.E.

    1989-10-01

    This document describes the Hanford Internal Dosimetry program. Program Services include administrating the bioassay monitoring program, evaluating and documenting assessments of internal exposure and dose, ensuring that analytical laboratories conform to requirements, selecting and applying appropriate models and procedures for evaluating internal radionuclide deposition and the resulting dose, and technically guiding and supporting Hanford contractors in matters regarding internal dosimetry. 13 refs., 16 figs., 42 tabs.

  15. A multicentre 'end to end' dosimetry audit for cervix HDR brachytherapy treatment.

    PubMed

    Palmer, Antony L; Diez, Patricia; Gandon, Laura; Wynn-Jones, Andrea; Bownes, Peter; Lee, Chris; Aird, Edwin; Bidmead, Margaret; Lowe, Gerry; Bradley, David; Nisbet, Andrew

    2015-02-01

    To undertake the first multicentre fully 'end to end' dosimetry audit for HDR cervix brachytherapy, comparing planned and delivered dose distributions around clinical treatment applicators, with review of local procedures. A film-dosimetry audit was performed at 46 centres, including imaging, applicator reconstruction, treatment planning and delivery. Film dose maps were calculated using triple-channel dosimetry and compared to RTDose data from treatment planning systems. Deviations between plan and measurement were quantified at prescription Point A and using gamma analysis. Local procedures were also discussed. The mean difference between planned and measured dose at Point A was -0.6% for plastic applicators and -3.0% for metal applicators, at standard uncertainty 3.0% (k=1). Isodose distributions agreed within 1mm over a dose range 2-16Gy. Mean gamma passing rates exceeded 97% for plastic and metal applicators at 3% (local) 2mm criteria. Two errors were found: one dose normalisation error and one applicator library misaligned with the imaged applicator. Suggestions for quality improvement were also made. The concept of 'end to end' dosimetry audit for HDR brachytherapy has been successfully implemented in a multicentre environment, providing evidence that a high level of accuracy in brachytherapy dosimetry can be achieved. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. [Childhood accidents: relevant epidemiologic data].

    PubMed

    Julé, Laure; Chevallier, Bertrand

    2009-02-20

    Injuries resulting from accidents are a major public heath problem. Accidents account for 700 deaths among French children up to 15 years and near 300 concern home accidents. Accidental injuries represent the first cause of children mortality, hospitalisations and sequelae. The lack of data registration supports the need of epidemiological tools to appreciate the burden of the public heath problem and the basis of a surveillance system to evaluate strategy prevention.

  17. Profile of an Accident Flying Squad

    PubMed Central

    Little, Keith

    1972-01-01

    An analysis of 184 accident flying squad calls and of 280 patients injured in road accidents and treated by a flying squad based on an accident department inclusive from 1967 to 1971 has shown that such a service can provide an efficient system without disrupting the routine work of the hospital. PMID:5076258

  18. 48 CFR 1836.513 - Accident prevention.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Accident prevention. 1836... 1836.513 Accident prevention. The contracting officer must insert the clause at 1852.223-70, Safety and Health, in lieu of FAR clause 52.236-13, Accident Prevention, and its Alternate I. [67 FR 17016, Apr. 9...

  19. 48 CFR 1836.513 - Accident prevention.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Accident prevention. 1836... 1836.513 Accident prevention. The contracting officer must insert the clause at 1852.223-70, Safety and Health, in lieu of FAR clause 52.236-13, Accident Prevention, and its Alternate I. [67 FR 17016, Apr. 9...

  20. System analysis with improved thermo-mechanical fuel rod models for modeling current and advanced LWR materials in accident scenarios

    NASA Astrophysics Data System (ADS)

    Porter, Ian Edward

    A nuclear reactor systems code has the ability to model the system response in an accident scenario based on known initial conditions at the onset of the transient. However, there has been a tendency for these codes to lack the detailed thermo-mechanical fuel rod response models needed for accurate prediction of fuel rod failure. This proposed work will couple today's most widely used steady-state (FRAPCON) and transient (FRAPTRAN) fuel rod models with a systems code TRACE for best-estimate modeling of system response in accident scenarios such as a loss of coolant accident (LOCA). In doing so, code modifications will be made to model gamma heating in LWRs during steady-state and accident conditions and to improve fuel rod thermal/mechanical analysis by allowing axial nodalization of burnup-dependent phenomena such as swelling, cladding creep and oxidation. With the ability to model both burnup-dependent parameters and transient fuel rod response, a fuel dispersal study will be conducted using a hypothetical accident scenario under both PWR and BWR conditions to determine the amount of fuel dispersed under varying conditions. Due to the fuel fragmentation size and internal rod pressure both being dependent on burnup, this analysis will be conducted at beginning, middle and end of cycle to examine the effects that cycle time can play on fuel rod failure and dispersal. Current fuel rod and system codes used by the Nuclear Regulatory Commission (NRC) are compilations of legacy codes with only commonly used light water reactor materials, Uranium Dioxide (UO2), Mixed Oxide (U/PuO 2) and zirconium alloys. However, the events at Fukushima Daiichi and Three Mile Island accident have shown the need for exploration into advanced materials possessing improved accident tolerance. This work looks to further modify the NRC codes to include silicon carbide (SiC), an advanced cladding material proposed by current DOE funded research on accident tolerant fuels (ATF). Several

  1. Sixth international radiopharmaceutical dosimetry symposium: Proceedings. Volume 2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    S.-Stelson, A.T.; Stabin, M.G.; Sparks, R.B.

    1999-01-01

    This conference was held May 7--10 in Gatlinburg, Tennessee. The purpose of this conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on radiopharmaceutical dosimetry. Attention is focused on the following: quantitative analysis and treatment planning; cellular and small-scale dosimetry; dosimetric models; radiopharmaceutical kinetics and dosimetry; and animal models, extrapolation, and uncertainty.

  2. SU-C-201-02: Dosimetric Verification of SBRT with FFF-VMAT Using a 3-D Radiochromic/Optical-CT Dosimetry System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Na, Y; Black, P; Wuu, C

    2016-06-15

    Purpose: With an increasing use of small field size and high dose rate irradiation in the advances of radiotherapy techniques, such as stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS), an in-depth quality assurance (QA) system is required. The purpose of this study is to investigate a high resolution optical CT-based 3D radiochromic dosimetry system for SBRT with intensity modulated radiotherapy (IMRT) and flattening filter free (FFF) volumetric modulated arc therapy (VMAT). Methods: Cylindrical PRESAGE radiochromic dosimeters of 10cm height and 11cm diameter were used to validate SBRT. Four external landmarks were placed on the surface of each dosimeter tomore » define the isocenter of target. SBRT plans were delivered using a Varian TrueBeam™ linear accelerator (LINAC). Three validation plans, SBRT with IMRT (6MV 600MU/min), FFF-VMAT (10MV 2400MU/min), and mixed FFF-VMAT (6MV 1400MU/min, 10MV 2400MU/min), were delivered to the PRESAGE dosimeters. Each irradiated PRESAGE dosimeter was scanned using a single laser beam optical CT scanner and reconstructed with a 1mm × 1mm high spatial resolution. The comparison of measured dose distributions of irradiated PRESAGE dosimeters to those calculated by Pinnacle{sup 3} treatment planning system (TPS) were performed with a 10% dose threshold, 3% dose difference (DD), and 3mm distance-to-agreement (DTA) Gamma criteria. Results: The average pass rates for the gamma comparisons between PRESAGE and Pinnacle{sup 3} in the transverse, sagittal, coronal planes were 94.6%, 95.9%, and 96.4% for SBRT with IMRT, FFF-VMAT, and mixed FFF-VMAT plans, respectively. A good agreement of the isodose distributions of those comparisons were shown at the isodose lines 50%, 70%, 80%, 90% and 98%. Conclusion: This study demonstrates the feasibility of the high resolution optical CT-based 3D radiochromic dosimetry system for validation of SBRT with IMRT and FFF-VMAT. This dosimetry system offers higher precision QA

  3. [The application of non-annealing thermoluminescent dosimetry (TLD)].

    PubMed

    Wu, J M; Chen, C S; Lan, R H

    1993-06-01

    Conventional use of Thermoluminescence (TL) in radiation dosimetry is very time-consuming. It requires repeating the procedures of preheating and annealing. In an attempt to simplify these procedures, we conducted an experiment of non-annealing TL dosimetry. This article reports the experiment's results. We adopted Lithium Fluoride (LiF) chip (TLD-100) in polystyrene under the exposure of Co-60, and the result was taken by HAR-SHAW-4000 TL reading system. The TL response was analyzed, including linearity, reproducibility and fading test. Because non-annealing TL response was greatly influenced by residual electron, TLD calibration curves were separated into two parts: (1) high dose region (HDR, 50-1500 cGy); (2) low dose region (LDR, 0-50 cGy). When TL dosimeters were exposed to a single high does (about 500 cGy), the HDR could be reproduced within 3% and fit a good linearity. For LDR, we had to give up the tail of glow curve in the high temperature region. We could then get good linearity and reproducibility. Furthermore, fading of non-annealing was apparently larger than annealing. We could control the fading of non-annealing was apparently larger than annealing. We could control the fading influence within 1% by taking the TL reading one hour after exposure. On the other hand, a combination of photon and electron exposure was also performed by non-annealing TL dosimetry. The results were compatible with Co-60 exposure in the same system.

  4. A new approach to modeling aviation accidents

    NASA Astrophysics Data System (ADS)

    Rao, Arjun Harsha

    General Aviation (GA) is a catchall term for all aircraft operations in the US that are not categorized as commercial operations or military flights. GA aircraft account for almost 97% of the US civil aviation fleet. Unfortunately, GA flights have a much higher fatal accident rate than commercial operations. Recent estimates by the Federal Aviation Administration (FAA) showed that the GA fatal accident rate has remained relatively unchanged between 2010 and 2015, with 1566 fatal accidents accounting for 2650 fatalities. Several research efforts have been directed towards betters understanding the causes of GA accidents. Many of these efforts use National Transportation Safety Board (NTSB) accident reports and data. Unfortunately, while these studies easily identify the top types of accidents (e.g., inflight loss of control (LOC)), they usually cannot identify why these accidents are happening. Most NTSB narrative reports for GA accidents are very short (many are only one paragraph long), and do not contain much information on the causes (likely because the causes were not fully identified). NTSB investigators also code each accident using an event-based coding system, which should facilitate identification of patterns and trends in causation, given the high number of GA accidents each year. However, this system is susceptible to investigator interpretation and error, meaning that two investigators may code the same accident differently, or omit applicable codes. To facilitate a potentially better understanding of GA accident causation, this research develops a state-based approach to check for logical gaps or omissions in NTSB accident records, and potentially fills-in the omissions. The state-based approach offers more flexibility as it moves away from the conventional event-based representation of accidents, which classifies events in accidents into several categories such as causes, contributing factors, findings, occurrences, and phase of flight. The method

  5. INTERCOMPARISON ON THE MEASUREMENT OF THE QUANTITY PERSONAL DOSE EQUIVALENT HP(10) IN PHOTON FIELDS. LINEARITY DEPENDENCE, LOWER LIMIT OF DETECTION AND UNCERTAINTY IN MEASUREMENT OF DOSIMETRY SYSTEMS OF INDIVIDUAL MONITORING SERVICES IN GABON AND GHANA.

    PubMed

    Ondo Meye, P; Schandorf, C; Amoako, J K; Manteaw, P O; Amoatey, E A; Adjei, D N

    2017-12-01

    An inter-comparison study was conducted to assess the capability of dosimetry systems of individual monitoring services (IMSs) in Gabon and Ghana to measure personal dose equivalent Hp(10) in photon fields. The performance indicators assessed were the lower limit of detection, linearity and uncertainty in measurement. Monthly and quarterly recording levels were proposed with corresponding values of 0.08 and 0.025 mSv, and 0.05 and 0.15 mSv for the TLD and OSL systems, respectively. The linearity dependence of the dosimetry systems was performed following the requirement given in the Standard IEC 62387 of the International Electrotechnical Commission (IEC). The results obtained for the two systems were satisfactory. The procedure followed for the uncertainty assessment is the one given in the IEC technical report TR62461. The maximum relative overall uncertainties, in absolute value, expressed in terms of Hp(10), for the TL dosimetry system Harshaw 6600, are 44. 35% for true doses below 0.40 mSv and 36.33% for true doses ≥0.40 mSv. For the OSL dosimetry system microStar, the maximum relative overall uncertainties, in absolute value, are 52.17% for true doses below 0.40 mSv and 37.43% for true doses ≥0.40 mSv. These results are in good agreement with the requirements for accuracy of the International Commission on Radiological protection. When expressing the uncertainties in terms of response, comparison with the IAEA requirements for overall accuracy showed that the uncertainty results were also acceptable. The values of Hp(10) directly measured by the two dosimetry systems showed a significant underestimation for the Harshaw 6600 system, and a slight overestimation for the microStar system. After correction for linearity of the measured doses, the two dosimetry systems gave better and comparable results. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Analysis of Alerting System Failures in Commercial Aviation Accidents

    NASA Technical Reports Server (NTRS)

    Mumaw, Randall J.

    2017-01-01

    The role of an alerting system is to make the system operator (e.g., pilot) aware of an impending hazard or unsafe state so the hazard can be avoided or managed successfully. A review of 46 commercial aviation accidents (between 1998 and 2014) revealed that, in the vast majority of events, either the hazard was not alerted or relevant hazard alerting occurred but failed to aid the flight crew sufficiently. For this set of events, alerting system failures were placed in one of five phases: Detection, Understanding, Action Selection, Prioritization, and Execution. This study also reviewed the evolution of alerting system schemes in commercial aviation, which revealed naive assumptions about pilot reliability in monitoring flight path parameters; specifically, pilot monitoring was assumed to be more effective than it actually is. Examples are provided of the types of alerting system failures that have occurred, and recommendations are provided for alerting system improvements.

  7. Accident diagnosis system based on real-time decision tree expert system

    NASA Astrophysics Data System (ADS)

    Nicolau, Andressa dos S.; Augusto, João P. da S. C.; Schirru, Roberto

    2017-06-01

    Safety is one of the most studied topics when referring to power stations. For that reason, sensors and alarms develop an important role in environmental and human protection. When abnormal event happens, it triggers a chain of alarms that must be, somehow, checked by the control room operators. In this case, diagnosis support system can help operators to accurately identify the possible root-cause of the problem in short time. In this article, we present a computational model of a generic diagnose support system based on artificial intelligence, that was applied on the dataset of two real power stations: Angra1 Nuclear Power Plant and Santo Antônio Hydroelectric Plant. The proposed system processes all the information logged in the sequence of events before a shutdown signal using the expert's knowledge inputted into an expert system indicating the chain of events, from the shutdown signal to its root-cause. The results of both applications showed that the support system is a potential tool to help the control room operators identify abnormal events, as accidents and consequently increase the safety.

  8. Fiber-coupled Luminescence Dosimetry in Therapeutic and Diagnostic Radiology

    NASA Astrophysics Data System (ADS)

    Andersen, Claus E.

    2011-05-01

    Fiber-coupled luminescence dosimetry is an emerging technology with several potentially attractive features of relevance for uses in therapeutic and diagnostic radiology: direct water equivalence (i.e. no significant perturbation of the radiation field in a water phantom or a patient), sub-mm detector size, high dynamic range (below a mGy to several Gy), microsecond time resolution, and absence of electrical wires or other electronics in the dosimeter probe head. Fiber-coupled luminescence dosimetry systems typically consist of one or more small samples of phosphor, e.g. a mg of plastic scintillator, attached to 10-20 m long optical fiber cables of plastic. During irradiation, each dosimeter probe spontaneously emits radioluminescence (RL) in proportion to the dose rate. The luminescence intensity can be detected with photomultiplier tubes, CCD cameras or other highly sensitive photodetectors. Some crystalline phosphors, such as carbon-doped aluminium oxide (Al2O3:C) have the ability to store charge produced in the crystal during irradiation. The stored charge may later be released by fiber-guided laser light under emission of so-called optically stimulated luminescence (OSL). The OSL signal therefore reflects the passively integrated dose. In contrast to thermoluminescence dosimetry, fiber-coupled OSL dosimetry may be performed in vivo while the dosimeter is still in the patient. Within the last few years, several improvements and new applications of these techniques have been published, and the objective of this review is to provide an introduction to this field and to outline some of these new results. Emphasis will be given to applications in medical dosimetry such as in vivo real-time dose verification in brachytherapy and methods aimed for improved quality assurance of linear accelerators.

  9. Thermoluminescence dosimetry applied to in vivo dose measurements for total body irradiation techniques.

    PubMed

    Duch, M A; Ginjaume, M; Chakkor, H; Ortega, X; Jornet, N; Ribas, M

    1998-06-01

    In total body irradiation (TBI) treatments in vivo dosimetry is recommended because it makes it possible to ensure the accuracy and quality control of dose delivery. The aim of this work is to set up an in vivo thermoluminescence dosimetry (TLD) system to measure the dose distribution during the TBI technique used prior to bone marrow transplant. Some technical problems due to the presence of lung shielding blocks are discussed. Irradiations were performed in the Hospital de la Santa Creu i Sant Pau by means of a Varian Clinac-1800 linear accelerator with 18 MV X-ray beams. Different TLD calibration experiments were set up to optimize in vivo dose assessment and to analyze the influence on dose measurement of shielding blocks. An algorithm to estimate midplane doses from entrance and exit doses is proposed and the estimated dose in critical organs is compared to internal dose measurements performed in an Alderson anthropomorphic phantom. The predictions of the dose algorithm, even in heterogeneous zones of the body such as the lungs, are in good agreement with the experimental results obtained with and without shielding blocks. The differences between measured and predicted values are in all cases lower than 2%. The TLD system described in this work has been proven to be appropriate for in vivo dosimetry in TBI irradiations. The described calibration experiments point out the difficulty of calibrating an in vivo dosimetry system when lung shielding blocks are used.

  10. In vivo dosimetry in external beam radiotherapy.

    PubMed

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-07-01

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20∕20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  11. The specifics of dosimetry for food irradiation applications

    NASA Astrophysics Data System (ADS)

    Kuntz, Florent; Strasser, Alain

    2016-12-01

    Dose measurement applied to food irradiation is obviously a very important and critical aspect of this process. It is described in many standards and guides. The application of appropriate dosimetry tools is explained. This helps to ensure traceability of this measurement and number of dosimeters available on the market are well studied even though theirs response should be characterized while used in routine processing conditions. When employed in low energy radiation fields, these dosimeters may exhibit specific response compared to the usual Cobalt 60 source irradiation. Traceable calibration or correction factor assessment of this energy dependency is mandatory. It is to mention that the absorbed dose is measured in the dosimeter itself and unfortunately not in/on the food product. However, existing dosimetry systems fulfill all relevant requirements.

  12. Issues and challenges for pedestrian active safety systems based on real world accidents.

    PubMed

    Hamdane, Hédi; Serre, Thierry; Masson, Catherine; Anderson, Robert

    2015-09-01

    The purpose of this study was to analyze real crashes involving pedestrians in order to evaluate the potential effectiveness of autonomous emergency braking systems (AEB) in pedestrian protection. A sample of 100 real accident cases were reconstructed providing a comprehensive set of data describing the interaction between the vehicle, the environment and the pedestrian all along the scenario of the accident. A generic AEB system based on a camera sensor for pedestrian detection was modeled in order to identify the functionality of its different attributes in the timeline of each crash scenario. These attributes were assessed to determine their impact on pedestrian safety. The influence of the detection and the activation of the AEB system were explored by varying the field of view (FOV) of the sensor and the level of deceleration. A FOV of 35° was estimated to be required to detect and react to the majority of crash scenarios. For the reaction of a system (from hazard detection to triggering the brakes), between 0.5 and 1s appears necessary. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. On the feasibility of comprehensive high-resolution 3D remote dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Juang, Titania; Grant, Ryan; Adamovics, John

    2014-07-15

    Purpose: This study investigates the feasibility of remote high-resolution 3D dosimetry with the PRESAGE®/Optical-CT system. In remote dosimetry, dosimeters are shipped out from a central base institution to a remote institution for irradiation, then shipped back to the base institution for subsequent readout and analysis. Methods: Two nominally identical optical-CT scanners for 3D dosimetry were constructed and placed at the base (Duke University) and remote (Radiological Physics Center) institutions. Two formulations of PRESAGE® (SS1, SS2) radiochromic dosimeters were investigated. Higher sensitivity was expected in SS1, which had higher initiator content (0.25% bromotrichloromethane), while greater temporal stability was expected in SS2.more » Four unirradiated PRESAGE® dosimeters (two per formulation, cylindrical dimensions 11 cm diameter, 8.5–9.5 cm length) were imaged at the base institution, then shipped to the remote institution for planning and irradiation. Each dosimeter was irradiated with the same simple treatment plan: an isocentric 3-field “cross” arrangement of 4 × 4 cm open 6 MV beams configured as parallel opposed laterals with an anterior beam. This simple plan was amenable to accurate and repeatable setup, as well as accurate dose modeling by a commissioned treatment planning system (Pinnacle). After irradiation and subsequent (within 1 h) optical-CT readout at the remote institution, the dosimeters were shipped back to the base institution for remote dosimetry readout 3 days postirradiation. Measured on-site and remote relative 3D dose distributions were registered to the Pinnacle dose calculation, which served as the reference distribution for 3D gamma calculations with passing criteria of 5%/2 mm, 3%/3 mm, and 3%/2 mm with a 10% dose threshold. Gamma passing rates, dose profiles, and color-maps were all used to assess and compare the performance of both PRESAGE® formulations for remote dosimetry. Results: The best agreements

  14. 41 CFR 101-39.401 - Reporting of accidents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Reporting of accidents...-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.4-Accidents and Claims § 101-39.401 Reporting of accidents. (a) The..., by telephone, or by facsimile machine of any accident in which the vehicle may be involved: (1) The...

  15. SU-E-T-475: Improvements to Total Body Irradiation Dosimetry Efficiency with EBT3 Radiochromic Film and a Template System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Butson, M; Pope, D; Whitaker, M

    Purpose: Total Body Irradiation (TBI) treatments are mainly used in a preparative regimen for haematopoietic stem cell (or bone marrow) transplantation. Our standard regimen is a 12 Gy / 6 fraction bi-daily technique. To evaluate the delivered dose homogeneity to the patient, EBT3 Gafchromic film is positioned at the head, neck, chest, pelvis and groin for all fractions. A system has been developed to simply and accurately prepare and readout the films for patient dose assessment. Methods: A process involving easy preparation and analysis has been produced to minimise the time requirements for TBI dosimetry. One sheet of EBT3 filmmore » is used to prepare treatment dosimeters for all fractions, including calibration films, and an automated dose analysis system for easy evaluation and calculation of estimated in-vivo doses was developed. A desktop scanner is used with a dedicated TBI film template to accurately position the films for Image J analysis and extraction. Dental wax bolus and zip-lock bag holders are used to hold the EBT3 film in place during irradiation. Results: To adequately provide dosimetry information for a 6 fraction, TBI patient, only one sheet of Gafchromic EBT3 film is required. The dosimeters are cut, using a template, into 19 mm squares which are then placed between two 30 mm x 30 mm x 4.5 mm wax blocks for bolus. All packages are prepared before the first treatment fraction. The scanning and analysis process can be completed in less than 10 minutes after a 240 min development period. Results have shown that a high level of accuracy and reproducibility can be achieved using the template system provided. Conclusion: Gafchromic EBT3 film provides an adequate in-vivo dosimetry measure for TBI patients. Using a template based system on a dedicated desktop scanner, in-vivo results can be ascertained quickly and accurately.« less

  16. Utilization of accident databases and fuzzy sets to estimate frequency of HazMat transport accidents.

    PubMed

    Qiao, Yuanhua; Keren, Nir; Mannan, M Sam

    2009-08-15

    Risk assessment and management of transportation of hazardous materials (HazMat) require the estimation of accident frequency. This paper presents a methodology to estimate hazardous materials transportation accident frequency by utilizing publicly available databases and expert knowledge. The estimation process addresses route-dependent and route-independent variables. Negative binomial regression is applied to an analysis of the Department of Public Safety (DPS) accident database to derive basic accident frequency as a function of route-dependent variables, while the effects of route-independent variables are modeled by fuzzy logic. The integrated methodology provides the basis for an overall transportation risk analysis, which can be used later to develop a decision support system.

  17. 41 CFR 101-39.407 - Accident records.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.4-Accidents and Claims § 101-39.407 Accident records. If GSA's records... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Accident records. 101-39.407 Section 101-39.407 Public Contracts and Property Management Federal Property Management...

  18. Dosimetry of gamma chamber blood irradiator using PAGAT gel dosimeter and Monte Carlo simulations

    PubMed Central

    Mohammadyari, Parvin; Zehtabian, Mehdi; Sina, Sedigheh; Tavasoli, Ali Reza

    2014-01-01

    Currently, the use of blood irradiation for inactivating pathogenic microbes in infected blood products and preventing graft‐versus‐host disease (GVHD) in immune suppressed patients is greater than ever before. In these systems, dose distribution and uniformity are two important concepts that should be checked. In this study, dosimetry of the gamma chamber blood irradiator model Gammacell 3000 Elan was performed by several dosimeter methods including thermoluminescence dosimeters (TLD), PAGAT gel dosimetry, and Monte Carlo simulations using MCNP4C code. The gel dosimeter was put inside a glass phantom and the TL dosimeters were placed on its surface, and the phantom was then irradiated for 5 min and 27 sec. The dose values at each point inside the vials were obtained from the magnetic resonance imaging of the phantom. For Monte Carlo simulations, all components of the irradiator were simulated and the dose values in a fine cubical lattice were calculated using tally F6. This study shows that PAGAT gel dosimetry results are in close agreement with the results of TL dosimetry, Monte Carlo simulations, and the results given by the vendor, and the percentage difference between the different methods is less than 4% at different points inside the phantom. According to the results obtained in this study, PAGAT gel dosimetry is a reliable method for dosimetry of the blood irradiator. The major advantage of this kind of dosimetry is that it is capable of 3D dose calculation. PACS number: 87.53.Bn PMID:24423829

  19. Dosimetry of ionising radiation in modern radiation oncology

    NASA Astrophysics Data System (ADS)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B.

    2016-07-01

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these.

  20. Severe Accident Scoping Simulations of Accident Tolerant Fuel Concepts for BWRs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Robb, Kevin R.

    2015-08-01

    Accident-tolerant fuels (ATFs) are fuels and/or cladding that, in comparison with the standard uranium dioxide Zircaloy system, can tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operations [1]. It is important to note that the currently used uranium dioxide Zircaloy fuel system tolerates design basis accidents (and anticipated operational occurrences and normal operation) as prescribed by the US Nuclear Regulatory Commission. Previously, preliminary simulations of the plant response have been performed under a range of accident scenarios using various ATF cladding concepts and fully ceramicmore » microencapsulated fuel. Design basis loss of coolant accidents (LOCAs) and station blackout (SBO) severe accidents were analyzed at Oak Ridge National Laboratory (ORNL) for boiling water reactors (BWRs) [2]. Researchers have investigated the effects of thermal conductivity on design basis accidents [3], investigated silicon carbide (SiC) cladding [4], as well as the effects of ATF concepts on the late stage accident progression [5]. These preliminary analyses were performed to provide initial insight into the possible improvements that ATF concepts could provide and to identify issues with respect to modeling ATF concepts. More recently, preliminary analyses for a range of ATF concepts have been evaluated internationally for LOCA and severe accident scenarios for the Chinese CPR1000 [6] and the South Korean OPR-1000 [7] pressurized water reactors (PWRs). In addition to these scoping studies, a common methodology and set of performance metrics were developed to compare and support prioritizing ATF concepts [8]. A proposed ATF concept is based on iron-chromium-aluminum alloys (FeCrAl) [9]. With respect to enhancing accident tolerance, FeCrAl alloys have substantially slower oxidation kinetics compared to the zirconium alloys typically employed. During a severe accident, Fe

  1. Can cultural differences lead to accidents? Team cultural differences and sociotechnical system operations.

    PubMed

    Strauch, Barry

    2010-04-01

    I discuss cultural factors and how they may influence sociotechnical system operations. Investigations of several major transportation accidents suggest that cultural factors may have played a role in the causes of the accidents. However, research has not fully addressed how cultural factors can influence sociotechnical systems. I review literature on cultural differences in general and cultural factors in sociotechnical systems and discuss how these differences can affect team performance in sociotechnical systems. Cultural differences have been observed in social and interpersonal dimensions and in cognitive and perceptual styles; these differences can affect multioperator team performance. Cultural factors may account for team errors in sociotechnical systems, most likely during high-workload, high-stress operational phases. However, much of the research on cultural factors has methodological and interpretive shortcomings that limit their applicability to sociotechnical systems. Although some research has been conducted on the role of cultural differences on team performance in sociotechnical system operations, considerable work remains to be done before the effects of these differences can be fully understood. I propose a model that illustrates how culture can interact with sociotechnical system operations and suggest avenues of future research. Given methodological challenges in measuring cultural differences and team performance in sociotechnical system operations, research in these systems should use a variety of methodologies to better understand how culture can affect multioperator team performance in these systems.

  2. The physics of small megavoltage photon beam dosimetry.

    PubMed

    Andreo, Pedro

    2018-02-01

    The increased interest during recent years in the use of small megavoltage photon beams in advanced radiotherapy techniques has led to the development of dosimetry recommendations by different national and international organizations. Their requirement of data suitable for the different clinical options available, regarding treatment units and dosimetry equipment, has generated a considerable amount of research by the scientific community during the last decade. The multiple publications in the field have led not only to the availability of new invaluable data, but have also contributed substantially to an improved understanding of the physics of their dosimetry. This work provides an overview of the most important aspects that govern the physics of small megavoltage photon beam dosimetry. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Fatal and Injury Accident Rates on Federal-Aid and Other Highway Systems/1975

    DOT National Transportation Integrated Search

    1977-01-28

    Data on fatal and nonfatal injuries in motor vehicle traffic accidents for calendar year 1975 are summarized by highway system in the tables. These tables, compiled from reports submitted to the Federal Highway Administration by the 50 States and the...

  4. Fatal and Injury Accident Rates on Federal-Aid and Other Highway Systems/1973

    DOT National Transportation Integrated Search

    1974-11-01

    Data on fatal and nonfatal injuries in motor vehicle traffic accidents for calendar year 1973 are summarized highway system in the tables. These tables, compiled from reports submitted by the 50 States and the District of Columbia, include data for a...

  5. Fatal and Injury Accident Rates on Federal-Aid and Other Highway Systems/1974

    DOT National Transportation Integrated Search

    1975-11-01

    Data on fatal and nonfatal injuries in motor vehicle traffic accidents for calendar year 1974 are summarized by highway system in the tables. These tables, compiled from reports submitted to the Federal Highway Administration by the 50 States and the...

  6. Dosimetry quality audit of high energy photon beams in greek radiotherapy centers.

    PubMed

    Hourdakis, Constantine J; Boziari, A

    2008-04-01

    Dosimetry quality audits and intercomparisons in radiotherapy centers is a useful tool in order to enhance the confidence for an accurate therapy and to explore and dissolve discrepancies in dose delivery. This is the first national comprehensive study that has been carried out in Greece. During 2002--2006 the Greek Atomic Energy Commission performed a dosimetry quality audit of high energy external photon beams in all (23) Greek radiotherapy centers, where 31 linacs and 13 Co-60 teletherapy units were assessed in terms of their mechanical performance characteristics and relative and absolute dosimetry. The quality audit in dosimetry of external photon beams took place by means of on-site visits, where certain parameters of the photon beams were measured, calculated and assessed according to a specific protocol and the IAEA TRS 398 dosimetry code of practice. In each radiotherapy unit (Linac or Co-60), certain functional parameters were measured and the results were compared to tolerance values and limits. Doses in water under reference and non reference conditions were measured and compared to the stated values. Also, the treatment planning systems (TPS) were evaluated with respect to irradiation time calculations. The results of the mechanical tests, dosimetry measurements and TPS evaluation have been presented in this work and discussed in detail. This study showed that Co-60 units had worse performance mechanical characteristics than linacs. 28% of all irradiation units (23% of linacs and 42% of Co-60 units) exceeded the acceptance limit at least in one mechanical parameter. Dosimetry accuracy was much worse in Co60 units than in linacs. 61% of the Co60 units exhibited deviations outside +/-3% and 31% outside +/-5%. The relevant percentages for the linacs were 24% and 7% respectively. The results were grouped for each hospital and the sources of errors (functional and human) have been investigated and discussed in details. This quality audit proved to be a

  7. A new paradigm in personal dosimetry using LiF:Mg,Cu,P.

    PubMed

    Cassata, J R; Moscovitch, M; Rotunda, J E; Velbeck, K J

    2002-01-01

    The United States Navy has been monitoring personnel for occupational exposure to ionising radiation since 1947. Film was exclusively used until 1973 when thermoluminescence dosemeters were introduced and used to the present time. In 1994, a joint research project between the Naval Dosimetry Center, Georgetown University, and Saint Gobain Crystals and Detectors (formerly Bicron RMP formerly Harshaw TLD) began to develop a state of the art thermoluminescent dosimetry system. The study was conducted from a large-scale dosimetry processor point of view with emphasis on a systems approach. Significant improvements were achieved by replacing the LiF:Mg,Ti with LiF:Mg,Cu,P TL elements due to the significant sensitivity increase, linearity, and negligible hiding. Dosemeter filters were optimised for gamma and X ray energy discrimination using Monte Carlo modelling (MCNP) resulting in significant improvement in accuracy and precision. Further improvements were achieved through the use of neural-network based dose calculation algorithms. Both back propagation and functional link methods were implemented and the data compared with essentially the same results. Several operational aspects of the system are discussed, including (1) background subtraction using control dosemeters, (2) selection criteria for control dosemeters, (3) optimisation of the TLD readers, (4) calibration methodology, and (5) the optimisation of the heating profile.

  8. Reviewing three dimensional dosimetry: basics and utilization as presented over 17 Years of DosGel and IC3Ddose

    NASA Astrophysics Data System (ADS)

    Schreiner, L. J.

    2017-05-01

    For seventeen years a community of basic and clinical scientists and researchers has been meeting bi-annually to promote the clinical advance of techniques to measure radiation dose in three dimensions. The interest in this dosimetry was motivated by its promise as an effective methodology for 3D measurement of the complex conformal dose distributions achieved by modern techniques such as Intensity Modulated and Volumetric Arc Radiation Therapy. Each of the International Conferences on 3D Radiation Dosimetry resulted in the publication of informative proceedings [1-8], the majority openly available on the internet. The proceedings included papers that: i) reviewed the basic science of the radiation sensitive materials used to accumulate the dose information, ii) introduced the science and engineering of the imaging systems required to read the information out, iii) described the work flows and systems required for efficient dosimetry, iv) reported the protocols required for reproducible dosimetry, and v) showed examples of clinical use illustrating advantage and limitations of the dosimetry. This paper is intended to use the framework provided by these proceedings to review the current 3D chemical dosimeters available and to discuss the requirements for their use. The paper describes how 3D dosimetry can complement other dose delivery validation approaches available in the clinic. It closes with some personal reflections of how the motivation for, and practice of, 3D dosimetry have changed (or not) over the years.

  9. Contributing factors in construction accidents.

    PubMed

    Haslam, R A; Hide, S A; Gibb, A G F; Gyi, D E; Pavitt, T; Atkinson, S; Duff, A R

    2005-07-01

    This overview paper draws together findings from previous focus group research and studies of 100 individual construction accidents. Pursuing issues raised by the focus groups, the accident studies collected qualitative information on the circumstances of each incident and the causal influences involved. Site based data collection entailed interviews with accident-involved personnel and their supervisor or manager, inspection of the accident location, and review of appropriate documentation. Relevant issues from the site investigations were then followed up with off-site stakeholders, including designers, manufacturers and suppliers. Levels of involvement of key factors in the accidents were: problems arising from workers or the work team (70% of accidents), workplace issues (49%), shortcomings with equipment (including PPE) (56%), problems with suitability and condition of materials (27%), and deficiencies with risk management (84%). Employing an ergonomics systems approach, a model is proposed, indicating the manner in which originating managerial, design and cultural factors shape the circumstances found in the work place, giving rise to the acts and conditions which, in turn, lead to accidents. It is argued that attention to the originating influences will be necessary for sustained improvement in construction safety to be achieved.

  10. The association between attributions of responsibility for motor vehicle accidents and patient satisfaction: a study within a no-fault injury compensation system.

    PubMed

    Thompson, Jason; Berk, Michael; O'Donnell, Meaghan; Stafford, Lesley; Nordfjaern, Trond

    2015-05-01

    This study set out to test the relationship between attributions of responsibility for motor vehicle accidents and satisfaction with personal injury compensation systems. The study analysed survey data from 1394 people injured in a motor vehicle accident who were compensated under a no-fault personal injury compensation system. Patients' ratings of satisfaction with the compensation system across five domains (resolves your issues, keeps you up-to-date, treats you as an individual, cares about you, and overall satisfaction) were analysed alongside patient attributions of responsibility for their accident (not responsible, partly responsible, totally responsible). Postaccident physical and mental health status, age, gender, and duration of compensation claim were controlled for in the analysis. A multivariate analysis of covariance indicated attributions of responsibility for accidents were significantly associated with levels of patient satisfaction across all five domains under study (F (10, 2084) = 3.7, p<0.001, η(2)  =0.02). Despite access to virtually indistinguishable services, patients who attributed responsibility for their accidents to others were significantly less satisfied with the injury compensation system than those who attributed responsibility to themselves. Satisfaction with no-fault motor vehicle injury compensation services are associated with patients' attributions of responsibility for their accident. Compensation systems and other rehabilitation services monitoring patient satisfaction should adjust for attributions of responsibility when assessing levels of patient satisfaction between time periods, services, or injured populations. Differences in levels of patient satisfaction observed between compensation or rehabilitation populations may reflect differences in attributions of responsibility for accidents rather than objective service quality. © The Author(s) 2014.

  11. Quad City Intersection Traffic Accident Study: 1993 Data

    DOT National Transportation Integrated Search

    1996-03-01

    Accident information is an important factor from which to work towards the : regional Transportation System Management (TSM) objective of improving the : safety of the local transportation system. The 1993 Quad City Intersection : Traffic Accident Re...

  12. Normal accidents: Living with high-risk technologies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Perrow, Ch.

    1984-01-01

    It was a major nuclear accident, the one at Three Mile Island in 1979, that turned Perrow's attention to accidents in general. A specialist in the sociology of organizations, he soon learned that events at TMI were not simply the result of an engineering failure or the result of operator error; rather, they were a consequence of systems failure. What the author learned from his research into the accident at TMI is that there was no coherent theory of accidents in either the engineering or the social science literature, so he set out to create one. This book discusses themore » science of accident research. Since Perrow is an outsider to all of the many technical fields reviewed in the book, ranging from nuclear power to marine transport to DNA research, experts may challenge his sources and point out his errors. Perrow's central thesis is that accidents are inevitable - that is, they are ''normal'' - in technologies that have two system characteristics that he terms ''interactive complexity'' and ''tight coupling''. Using these concepts, Perrow constructs a theory of systems which he believes to be unique in the literature on accidents and the literature on organizations. His theory concentrates upon the properties of systems themselves, rather than on the errors that owners, designers and operators make in running them. He seeks a more basic explanation than operator error; faulty design or equipment; inadequately trained personnel; or the system is too big, under-financed or mismanaged. Nuclear power in the United States may not survive its current economic and regulatory troubles, but discussion continues. Only a small part of the debate concerns plant safety: economic competitiveness, nuclear arms proliferation and nuclear waste disposal are the salient themes.« less

  13. Dosimetry with diamond detectors

    NASA Astrophysics Data System (ADS)

    Gervino, G.; Marino, C.; Silvestri, F.; Lavagno, A.; Truc, F.

    2010-05-01

    In this paper we present the dosimetry analysis in terms of stability and repeatability of the signal and dose rate dependence of a synthetic single crystal diamond grown by Chemical Vapor Deposition (CVD) technique. The measurements carried out by 5 MeV X-ray photons beam show very promising results, even if the dose rate detector response points out that the charge trapping centers distribution is not uniform inside the crystal volume. This handicap that affects the detectors performances, must be ascribed to the growing process. Synthetic single crystal diamonds could be a valuable alternative to air ionization chambers for quality beam control and for intensity modulated radiation therapy beams dosimetry.

  14. The three essentials for accident prevention.

    PubMed

    Eastman, Crystal

    2014-11-01

    This article was written by Crystal Eastman when she was Secretary of the New York Commission on Employers' Liability and Causes of Industrial Accidents, Unemployment, and Lack of Farm Labor. It was published in July of 1911, in Volume 38, Number 1 of the Annals of the American Academy of Political and Social Science, pages 98-107. The issue title was "Risks in Modern Industry." Eastman calls for the prevention of workplace accidents through three essentials: injury surveillance/reporting (with annual public reporting of the data); government enforcement of accident prevention laws, via departments with well-paid and well-trained officials and inspectors, fines that are high enough to be a deterrence to employers, and the power to have police shut down a factory if preventive measures are not installed; and a workers' compensation system-"a system of liability by which an employer can reduce his accident costs, not by hiring a more unscrupulous attorney and a more hard-hearted claim agent, but only by reducing his accidents."

  15. [Medical protection during radiation accidents: some results and lessons of the Chernobyl accident].

    PubMed

    Legeza, V I; Grebeniuk, A N; Zatsepin, V V

    2011-01-01

    Actions of medical radiation protection of liquidators of consequences of on Chernobyl atomic power station accident are analysed. It is shown, that during the early period of the accident medical protection of liquidators was provided by administration of radioprotectors, means of prophylaxis: of radioactive iodine incorporation and agent for preventing psychological and emotional stress. When carrying out decontamination and regenerative works, preparations which action is caused by increase of nonspecific resistance of an organism were applied. The lessons taken from the results of the Chernobyl accident, have allowed one to improve the system of medical protection and to introduce in practice new highly effective radioprotective agents.

  16. EANM Dosimetry Committee series on standard operational procedures for pre-therapeutic dosimetry II. Dosimetry prior to radioiodine therapy of benign thyroid diseases.

    PubMed

    Hänscheid, Heribert; Canzi, Cristina; Eschner, Wolfgang; Flux, Glenn; Luster, Markus; Strigari, Lidia; Lassmann, Michael

    2013-07-01

    The EANM Dosimetry Committee Series "Standard Operational Procedures for Pre-Therapeutic Dosimetry" (SOP) provides advice to scientists and clinicians on how to perform patient-specific absorbed dose assessments. This particular SOP describes how to tailor the therapeutic activity to be administered for radioiodine therapy of benign thyroid diseases such as Graves' disease or hyperthyroidism. Pretherapeutic dosimetry is based on the assessment of the individual (131)I kinetics in the target tissue after the administration of a tracer activity. The present SOP makes proposals on the equipment to be used and guides the user through the measurements. Time schedules for the measurement of the fractional (131)I uptake in the diseased tissue are recommended and it is shown how to calculate from these datasets the therapeutic activity necessary to administer a predefined target dose in the subsequent therapy. Potential sources of error are pointed out and the inherent uncertainties of the procedures depending on the number of measurements are discussed. The theoretical background and the derivation of the listed equations from compartment models of the iodine kinetics are explained in a supplementary file published online only.

  17. How Past Loss of Control Accidents May Inform Safety Cases for Advanced Control Systems on Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Holloway, C. M.; Johnson, C. W.

    2008-01-01

    This paper describes five loss of control accidents involving commercial aircraft, and derives from those accidents three principles to consider when developing a potential safety case for an advanced flight control system for commercial aircraft. One, among the foundational evidence needed to support a safety case is the availability to the control system of accurate and timely information about the status and health of relevant systems and components. Two, an essential argument to be sustained in the safety case is that pilots are provided with adequate information about the control system to enable them to understand the capabilities that it provides. Three, another essential argument is that the advanced control system will not perform less safely than a good pilot.

  18. SU-G-TeP2-03: Comparison of Standard Dosimetry Protocol in Japan and AAPM TG-51 Addendum in Order to Establish Optimal Dosimetry for FFF Beam

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Matsunaga, T; Adachi, Y; Hayashi, N

    Purpose: Japan Standard Dosimetry of Absorbed dose to water in external beam radiotherapy (JSDP12) is widely used to measure radiation dose in radiotherapy. However, JSDP12 does not take flattening-filter-free (FFF) beam into consideration. In addition, JSDP12 applied TPR20,10 for dose quality index for photon beam. The purpose of this study is to compare JSDP12 with AAPM TG-51 addendum in order to establish optimal dosimetry procedure for FFF beam. Method: We evaluated the ion-recombination factor (ks) and the correction factor of radial beam profile (Prp) in FFF beam dosimetry. The ks was introduced by 2 voltages method and verified by Jaffe’smore » plot. The Prp was given by both film measurement and calculation of treatment planning system, and compared them. Next, we compared the dose quality indexes (kQ) between TPR20,10 method and PDD(10)x method. Finally we considered optimal dosimetry protocol for FFF photon beam using JSDP12 with referring TG-51 addendum protocols. The FFF photon beams of 6 MV (6X-FFF) and 10 MV (10X-FFF) from TrueBeam were investigated in this study. Results: The ks for 6X-FFF and 10X-FFF beams were 1.005 and 1.010, respectively. The Prp of 0.6 cc ionization chamber for 6X-FFF and 10X-FFF beams (Film, TPS) were (1.004, 1.008) and (1.005, 1.008), respectively. The kQ for 6X-FFF and 10X-FFF beams (JSDP12, TG-51 addendum) were (0.9950, 0.9947) and (0.9851, 0.9845), respectively. The most effective factor for uncertainty in FFF photon beam measurement was Prp for JSDP12 formalism. Total dosimetric differences between JSDP12 and TG-51 addendum for 6X-FFF and 10X-FFF were -0.47% and -0.73%, respectively. Conclusion: The total dosimetric difference between JSDP12 and TG-51 addendum was within 1%. The introduction of kQ given by JSDP is feasible for FFF photon beam dosimetry. However, we think Prp should be considered for optimal dosimetry procedure even if JSDP12 is used for FFF photon beam dosimetry.« less

  19. Normal Accident at Three Mile Island.

    ERIC Educational Resources Information Center

    Perrow, Charles

    1981-01-01

    Discusses some aspects of the accident at the Three Mile Island nuclear power plant. Explains a number of factors involved including the type of accident, warnings, design and equipment failure, operator error, and negative synergy. Presents alternatives to systems with catastrophic potential. (MK)

  20. Occurrence and countermeasures of urban power grid accident

    NASA Astrophysics Data System (ADS)

    Wei, Wang; Tao, Zhang

    2018-03-01

    With the advance of technology, the development of network communication and the extensive use of power grids, people can get to know power grid accidents around the world through the network timely. Power grid accidents occur frequently. Large-scale power system blackout and casualty accidents caused by electric shock are also fairly commonplace. All of those accidents have seriously endangered the property and personal safety of the country and people, and the development of society and economy is severely affected by power grid accidents. Through the researches on several typical cases of power grid accidents at home and abroad in recent years and taking these accident cases as the research object, this paper will analyze the three major factors that cause power grid accidents at present. At the same time, combining with various factors and impacts caused by power grid accidents, the paper will put forward corresponding solutions and suggestions to prevent the occurrence of the accident and lower the impact of the accident.

  1. Retrospective dosimetry analyses of reactor vessel cladding samples

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Greenwood, L. R.; Soderquist, C. Z.; Fero, A. H.

    2011-07-01

    Reactor pressure vessel cladding samples for Ringhals Units 3 and 4 in Sweden were analyzed using retrospective reactor dosimetry techniques. The objective was to provide the best estimates of the neutron fluence for comparison with neutron transport calculations. A total of 51 stainless steel samples consisting of chips weighing approximately 100 to 200 mg were removed from selected locations around the pressure vessel and were sent to Pacific Northwest National Laboratory for analysis. The samples were fully characterized and analyzed for radioactive isotopes, with special interest in the presence of Nb-93m. The RPV cladding retrospective dosimetry results will be combinedmore » with a re-evaluation of the surveillance capsule dosimetry and with ex-vessel neutron dosimetry results to form a comprehensive 3D comparison of measurements to calculations performed with 3D deterministic transport code. (authors)« less

  2. A systems modeling methodology for evaluation of vehicle aggressivity in the automotive accident environment

    DOT National Transportation Integrated Search

    2001-03-05

    A systems modeling approach is presented for assessment of harm in the automotive accident environment. The methodology is presented in general form and then applied to evaluate vehicle aggressivity in frontal crashes. The methodology consists of par...

  3. Factors associated with automobile accidents and survival.

    PubMed

    Kim, Hong Sok; Kim, Hyung Jin; Son, Bongsoo

    2006-09-01

    This paper develops an econometric model for vehicles' inherent mortality rate and estimates the probability of accidents and survival in the United States. Logistic regression model is used to estimate probability of survival, and censored regression model is used to estimate probability of accidents. The estimation results indicated that the probability of accident and survival are influenced by the physical characteristics of the vehicles involved in the accident, and by the characteristics of the driver and the occupants. Using restrain system and riding in heavy vehicle increased the survival rate. Middle-aged drivers are less susceptible to involve in an accident, and surprisingly, female drivers are more likely to have an accident than male drivers. Riding in powerful vehicles (high horsepower) and driving late night increase the probability of accident. Overall, the driving behavior and characteristics of vehicle does matter and affects the probabilities of having a fatal accident for different types of vehicles.

  4. SU-E-T-586: Optimal Determination of Tolerance Level for Radiation Dose Delivery Verification in An in Vivo Dosimetry System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Y; Souri, S; Gill, G

    Purpose: To statistically determine the optimal tolerance level in the verification of delivery dose compared to the planned dose in an in vivo dosimetry system in radiotherapy. Methods: The LANDAUER MicroSTARii dosimetry system with screened nanoDots (optically stimulated luminescence dosimeters) was used for in vivo dose measurements. Ideally, the measured dose should match with the planned dose and falls within a normal distribution. Any deviation from the normal distribution may be redeemed as a mismatch, therefore a potential sign of the dose misadministration. Randomly mis-positioned nanoDots can yield a continuum background distribution. A percentage difference of the measured dose tomore » its corresponding planned dose (ΔD) can be used to analyze combined data sets for different patients. A model of a Gaussian plus a flat function was used to fit the ΔD distribution. Results: Total 434 nanoDot measurements for breast cancer patients were collected across a period of three months. The fit yields a Gaussian mean of 2.9% and a standard deviation (SD) of 5.3%. The observed shift of the mean from zero is attributed to the machine output bias and calibration of the dosimetry system. A pass interval of −2SD to +2SD was applied and a mismatch background was estimated to be 4.8%. With such a tolerance level, one can expect that 99.99% of patients should pass the verification and at most 0.011% might have a potential dose misadministration that may not be detected after 3 times of repeated measurements. After implementation, a number of new start breast cancer patients were monitored and the measured pass rate is consistent with the model prediction. Conclusion: It is feasible to implement an optimal tolerance level in order to maintain a low limit of potential dose misadministration while still to keep a relatively high pass rate in radiotherapy delivery verification.« less

  5. Industrial accidents triggered by lightning.

    PubMed

    Renni, Elisabetta; Krausmann, Elisabeth; Cozzani, Valerio

    2010-12-15

    Natural disasters can cause major accidents in chemical facilities where they can lead to the release of hazardous materials which in turn can result in fires, explosions or toxic dispersion. Lightning strikes are the most frequent cause of major accidents triggered by natural events. In order to contribute towards the development of a quantitative approach for assessing lightning risk at industrial facilities, lightning-triggered accident case histories were retrieved from the major industrial accident databases and analysed to extract information on types of vulnerable equipment, failure dynamics and damage states, as well as on the final consequences of the event. The most vulnerable category of equipment is storage tanks. Lightning damage is incurred by immediate ignition, electrical and electronic systems failure or structural damage with subsequent release. Toxic releases and tank fires tend to be the most common scenarios associated with lightning strikes. Oil, diesel and gasoline are the substances most frequently released during lightning-triggered Natech accidents. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Development and demonstration of 2D dosimetry using optically stimulated luminescence from new Al2O3 films for radiotherapy applications

    NASA Astrophysics Data System (ADS)

    Ahmed, Md Foiez

    Scope and Method of Study: The goal of this work was to develop and demonstrate a 2D dosimetry system based on the optically stimulated luminescence (OSL) from new Al2O3 films for radiotherapy applications. A 2D laser-scanning system was developed for the readout and two OSL films (Al2O3:C and Al2O3:C,Mg) were tested. A dose reconstruction algorithm addressing corrections required for the characteristic material properties and the properties related to the system design was developed. The dosimetric properties of the system were tested using clinical X-ray (6 MV) beam. The feasibility of small field dosimetry was tested using heavy ion beams (221 MeV proton and 430 MeV 12C beam). For comparison, clinical tests were performed with ionization chamber, diode arrays and the commercial radiochromic films (Gafchromic EBT3) when applicable. Findings and Conclusions: The results demonstrate that the developed image reconstruction algorithm enabled > 300x faster laser-scanning readout of the Al2O3 films, eliminating the restriction imposed by its slow luminescence decay. The algorithm facilitates submillimeter spatial resolution, reduces the scanner position dependence (of light collection efficiency) and removes the inherent galvo geometric distortion, among other corrections. The system has a background signal < 1 mGy, linearity correction factor of < 10% up to ˜4.0 Gy and < 2% dose uncertainty over the clinically relevant dose range of 0.1 - 30 Gy. The system has a dynamic range of 4 - 5 orders, only limited by PMT linearity. The absolute response from Al2O2:C films is higher than Al2O 2:C,Mg films, but with lower image signal-to-noise ratio due to lower concentration of fast F+-center emission. As a result, Al2O2:C,Mg films are better suited than Al2O3:C films for small field dosimetry, which requires precise dosimetry with sub-millimeter spatial resolution. The dose uncertainty associated with OSL film dosimetry is lower than that associated with EBT3 film dosimetry

  7. Specific issues in small animal dosimetry and irradiator calibration

    PubMed Central

    Yoshizumi, Terry; Brady, Samuel L.; Robbins, Mike E.; Bourland, J. Daniel

    2013-01-01

    Purpose In response to the increased risk of radiological terrorist attack, a network of Centers for Medical Countermeasures against Radiation (CMCR) has been established in the United States, focusing on evaluating animal model responses to uniform, relatively homogenous whole- or partial-body radiation exposures at relatively high dose rates. The success of such studies is dependent not only on robust animal models but on accurate and reproducible dosimetry within and across CMCR. To address this issue, the Education and Training Core of the Duke University School of Medicine CMCR organised a one-day workshop on small animal dosimetry. Topics included accuracy in animal dosimetry accuracy, characteristics and differences of cesium-137 and X-ray irradiators, methods for dose measurement, and design of experimental irradiation geometries for uniform dose distributions. This paper summarises the information presented and discussed. Conclusions Without ensuring accurate and reproducible dosimetry the development and assessment of the efficacy of putative countermeasures will not prove successful. Radiation physics support is needed, but is often the weakest link in the small animal dosimetry chain. We recommend: (i) A user training program for new irradiator users, (ii) subsequent training updates, and (iii) the establishment of a national small animal dosimetry center for all CMCR members. PMID:21961967

  8. United States Department of Energy severe accident research following the Fukushima Daiichi accidents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Farmer, M. T.; Corradini, M.; Rempe, J.

    The U.S. Department of Energy (DOE) has played a major role in the U.S. response to the events at Fukushima Daiichi. During the first several weeks following the accident, U.S. assistance efforts were guided by results from a significant and diverse set of analyses. In the months that followed, a coordinated analysis activity aimed at gaining a more thorough understanding of the accident sequence was completed using laboratory-developed, system-level best-estimate accident analysis codes, while a parallel analysis was conducted by U.S. industry. A comparison of predictions for Unit 1 from these two studies indicated significant differences between MAAP and MELCORmore » results for key plant parameters, such as in-core hydrogen production. On that basis, a crosswalk was completed to determine the key modeling variations that led to these differences. In parallel with these activities, it became clear that there was a need to perform a technology gap evaluation on accident-tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist given the current state of light water reactor (LWR) severe accident research and augmented by insights from Fukushima. In addition, there is growing international recognition that data from Fukushima could significantly reduce uncertainties related to severe accident progression, particularly for boiling water reactors. On these bases, a group of U. S. experts in LWR safety and plant operations was convened by the DOE Office of Nuclear Energy (DOE-NE) to complete technology gap analysis and Fukushima forensics data needs identification activities. The results from these activities were used as the basis for refining DOE-NE's severe accident research and development (R&D) plan. Finally, this paper provides a high-level review of DOE-sponsored R&D efforts in these areas, including planned activities on accident-tolerant components and accident analysis methods.« less

  9. United States Department of Energy severe accident research following the Fukushima Daiichi accidents

    DOE PAGES

    Farmer, M. T.; Corradini, M.; Rempe, J.; ...

    2016-11-02

    The U.S. Department of Energy (DOE) has played a major role in the U.S. response to the events at Fukushima Daiichi. During the first several weeks following the accident, U.S. assistance efforts were guided by results from a significant and diverse set of analyses. In the months that followed, a coordinated analysis activity aimed at gaining a more thorough understanding of the accident sequence was completed using laboratory-developed, system-level best-estimate accident analysis codes, while a parallel analysis was conducted by U.S. industry. A comparison of predictions for Unit 1 from these two studies indicated significant differences between MAAP and MELCORmore » results for key plant parameters, such as in-core hydrogen production. On that basis, a crosswalk was completed to determine the key modeling variations that led to these differences. In parallel with these activities, it became clear that there was a need to perform a technology gap evaluation on accident-tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist given the current state of light water reactor (LWR) severe accident research and augmented by insights from Fukushima. In addition, there is growing international recognition that data from Fukushima could significantly reduce uncertainties related to severe accident progression, particularly for boiling water reactors. On these bases, a group of U. S. experts in LWR safety and plant operations was convened by the DOE Office of Nuclear Energy (DOE-NE) to complete technology gap analysis and Fukushima forensics data needs identification activities. The results from these activities were used as the basis for refining DOE-NE's severe accident research and development (R&D) plan. Finally, this paper provides a high-level review of DOE-sponsored R&D efforts in these areas, including planned activities on accident-tolerant components and accident analysis methods.« less

  10. Korean standard nuclear plant ex-vessel neutron dosimetry program Ulchin 4

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duo, J.I.; Chen, J.; Kulesza, J.A.

    2011-07-01

    A comprehensive ex-vessel neutron dosimetry (EVND) surveillance program has been deployed in 16 pressurized water reactors (PWR) in South Korea and EVND dosimetry sets have already been installed and analyzed in Westinghouse reactor designs. In this paper, the unique features of the design, training, and installation in the Korean standard nuclear plant (KSNP) Ulchin Unit 4 are presented. Ulchin Unit 4 Cycle 9 represents the first dosimetry analyzed from the EVND design deployed in KSNP plants: Yonggwang Units 3 through 6 and Ulchin Units 3 through 6. KSNP's cavity configuration precludes a conventional installation from the cavity floor. The solution,more » requiring the installation crew to access the cavity at an elevation of the active core, places a premium on rapid installation due to high area dose rates. Numerous geometrical features warranted the use of a detailed design in true 3D mechanical design software to control interferences. A full-size training mockup maximized the crew ability to correctly install the instrument in minimum time. The analysis of the first dosimetry set shows good agreements between measurement and calculation within the associated uncertainties. A complete EVND system has been successfully designed, installed, and analyzed for a KNSP plant. Current and future EVND analyses will continue supporting the successful operation of PWR units in South Korea. (authors)« less

  11. Thermoluminescence characteristics of Israeli household salts for retrospective dosimetry in radiological events

    NASA Astrophysics Data System (ADS)

    Druzhyna, S.; Datz, H.; Horowitz, Y. S.; Oster, L.; Orion, I.

    2016-06-01

    Following a nuclear accident or terror attack involving the dispersal of radioactive substances, radiation dose assessment to first responders and the members of the public is essential. The need for a retrospective assessment of the radiation dose to those possibly affected is, therefore, obligatory. The present study examines the potential use of Israeli household salt as a retrospective dosimeter (RD). The experiments were carried out on Israeli salt samples (NaCl) following a Nielsen market track survey based on scanning data representing the barcoded market, including organized and independent retail chains and a sample of private minimarkets and supermarkets. The technique used was thermoluminescence (TL) dosimetry. Salt samples were exposed to levels of dose from 0.5 mGy to 300 Gy at the Israeli Secondary Standard Dosimetry Laboratory of the Soreq Nuclear Research Center using a calibrated 137Cs source. Our emphasis has been on a detailed investigation of the basic dosimetric characteristics of the salts including: (i) glow curve analysis (ii) individual glow peak dose response (iii) reproducibility (iv) estimation of minimal measurable dose (v) effect of nitrogen readout, (vi) influence of humidity during pre-irradiation storage and (vii) light induced fading. The results are sufficiently favorable to lead to the conclusion that the Israeli household salts can serve as a pragmatic potential candidate for RD under certain restricted conditions. Occasional pre-calibration of the major salt brands in a dedicated laboratory may be essential depending on the required accuracy in the estimation of dose and consequent clinical evaluation.

  12. Using operational equipment to read accident dosemeters.

    PubMed

    Devine, R T; Vigil, M M; Martinez, W A

    2004-01-01

    Analysis of accident dosemeters usually involves the use of laboratory-based counting equipment. Gamma spectrometers are used for indium, copper and gold, and alpha-beta detectors for sulphur. This equipment is usually not easily transported due to the shielding required and the weight and delicacy of the counters. For intercomparison studies that require reading the dosemeters on site, a transportable system is required unless the site operating the study can count samples for all the participants. In the case of an actual accident these systems would have a difficulty in counting a large number of accident dosemeters. In an accident, personnel are usually subdivided according to their level of exposure. Those exposed to higher doses are treated immediately. An alternate system should be made available to handle the dosemeters worn by those personnel are likely to receive lower doses. Improvements in portable operational equipment for gamma and beta monitoring allow their use as spectrometers. Such a system was used for the SILENE intercomparison conducted at IRSN Valduc on 12 June and 19, 2002, and the preliminary results compared well with the other participants.

  13. [Skiing accidents in children (author's transl)].

    PubMed

    Schwarzenbach, M; Röthlisberger, M; Herwig, K; Biener, K

    1981-03-13

    In Arosa, a coherent skiing arena, all skiing accidents were systemically recorded by the two general practitioners for 10 years. The incidence of accidents to children compared with that of adolescents and adults was of particular interest. The incidence of accidents to children has more markedly decreased. The frequency of collisions is increasing. The most common injuries to children are fractures, followed by sprains and contusions. On the other hand sprains are the most common injury to adolescents and adults, followed by fractures and an almost equal number of contusions. The dangers of skiing and the severity of the injuries are discussed. Demands are made for prevention of skiing accidents.

  14. Thermoluminescence Dosimetry (TLD) and its Application in Medical Physics

    NASA Astrophysics Data System (ADS)

    Azorín Nieto, Juan

    2004-09-01

    Radiation dosimetry is fundamental in Medical Physics, involving patients and phantom dosimetry. In both cases thermoluminescence dosimetry (TLD) is the most appropriate technique for measuring the absorbed dose. In this paper thermoluminescence phenomenon as well as the use of TLD in radiodiagnosis and radiotherapy for in vivo or in phantom measurements is discussed. Some results of measurements made in radiotherapy and radiodiagnosis using home made LiF:Mg,Cu,P+PTFE TLD are presented.

  15. Investigation of thermoluminescence properties of mobile phone screen displays as dosimeters for accidental dosimetry

    NASA Astrophysics Data System (ADS)

    Mrozik, Anna; Marczewska, B.; Bilski, P.; Kłosowski, M.

    2014-11-01

    The rapid assessment of the radiation dose after unexpected exposure is a task of accidental dosimetry. In case of a radiological accident glasses originating from mobile phone screens, placed usually near the human body, could be used as emergency thermoluminescent (TL) personal dosimeters. The time between irradiation and TL readout is crucial and therefore preparation of the mobile phone screens and their readout conditions should be optimized. The influence of the samples etching, bleaching and selection of the optical filters based on measurement of the emission spectrum of irradiated glass samples during heating for different types of mobile phones were the subjects of our investigation. Obtained results showed that glasses extracted from different brands of mobile phones have different dosimetric properties but all of them give a luminescent signal which can be used to calculate the dose.

  16. Evaluation and implementation of triple‐channel radiochromic film dosimetry in brachytherapy

    PubMed Central

    Bradley, David; Nisbet, Andrew

    2014-01-01

    The measurement of dose distributions in clinical brachytherapy, for the purpose of quality control, commissioning or dosimetric audit, is challenging and requires development. Radiochromic film dosimetry with a commercial flatbed scanner may be suitable, but careful methodologies are required to control various sources of uncertainty. Triple‐channel dosimetry has recently been utilized in external beam radiotherapy to improve the accuracy of film dosimetry, but its use in brachytherapy, with characteristic high maximum doses, steep dose gradients, and small scales, has been less well researched. We investigate the use of advanced film dosimetry techniques for brachytherapy dosimetry, evaluating uncertainties and assessing the mitigation afforded by triple‐channel dosimetry. We present results on postirradiation film darkening, lateral scanner effect, film surface perturbation, film active layer thickness, film curling, and examples of the measurement of clinical brachytherapy dose distributions. The lateral scanner effect in brachytherapy film dosimetry can be very significant, up to 23% dose increase at 14 Gy, at ± 9 cm lateral from the scanner axis for simple single‐channel dosimetry. Triple‐channel dosimetry mitigates the effect, but still limits the useable width of a typical scanner to less than 8 cm at high dose levels to give dose uncertainty to within 1%. Triple‐channel dosimetry separates dose and dose‐independent signal components, and effectively removes disturbances caused by film thickness variation and surface perturbations in the examples considered in this work. The use of reference dose films scanned simultaneously with brachytherapy test films is recommended to account for scanner variations from calibration conditions. Postirradiation darkening, which is a continual logarithmic function with time, must be taken into account between the reference and test films. Finally, films must be flat when scanned to avoid the Callier

  17. A Comparison of Singlet Oxygen Explicit Dosimetry (SOED) and Singlet Oxygen Luminescence Dosimetry (SOLD) for Photofrin-Mediated Photodynamic Therapy

    PubMed Central

    Kim, Michele M.; Penjweini, Rozhin; Gemmell, Nathan R.; Veilleux, Israel; McCarthy, Aongus; Buller, Gerald S.; Hadfield, Robert H.; Wilson, Brian C.; Zhu, Timothy C.

    2016-01-01

    Accurate photodynamic therapy (PDT) dosimetry is critical for the use of PDT in the treatment of malignant and nonmalignant localized diseases. A singlet oxygen explicit dosimetry (SOED) model has been developed for in vivo purposes. It involves the measurement of the key components in PDT—light fluence (rate), photosensitizer concentration, and ground-state oxygen concentration ([3O2])—to calculate the amount of reacted singlet oxygen ([1O2]rx), the main cytotoxic component in type II PDT. Experiments were performed in phantoms with the photosensitizer Photofrin and in solution using phosphorescence-based singlet oxygen luminescence dosimetry (SOLD) to validate the SOED model. Oxygen concentration and photosensitizer photobleaching versus time were measured during PDT, along with direct SOLD measurements of singlet oxygen and triplet state lifetime (τΔ and τt), for various photosensitizer concentrations to determine necessary photophysical parameters. SOLD-determined cumulative [1O2]rx was compared to SOED-calculated [1O2]rx for various photosensitizer concentrations to show a clear correlation between the two methods. This illustrates that explicit dosimetry can be used when phosphorescence-based dosimetry is not feasible. Using SOED modeling, we have also shown evidence that SOLD-measured [1O2]rx using a 523 nm pulsed laser can be used to correlate to singlet oxygen generated by a 630 nm laser during a clinical malignant pleural mesothelioma (MPM) PDT protocol by using a conversion formula. PMID:27929427

  18. A Comparison of Singlet Oxygen Explicit Dosimetry (SOED) and Singlet Oxygen Luminescence Dosimetry (SOLD) for Photofrin-Mediated Photodynamic Therapy.

    PubMed

    Kim, Michele M; Penjweini, Rozhin; Gemmell, Nathan R; Veilleux, Israel; McCarthy, Aongus; Buller, Gerald S; Hadfield, Robert H; Wilson, Brian C; Zhu, Timothy C

    2016-12-06

    Accurate photodynamic therapy (PDT) dosimetry is critical for the use of PDT in the treatment of malignant and nonmalignant localized diseases. A singlet oxygen explicit dosimetry (SOED) model has been developed for in vivo purposes. It involves the measurement of the key components in PDT-light fluence (rate), photosensitizer concentration, and ground-state oxygen concentration ([³ O ₂])-to calculate the amount of reacted singlet oxygen ([¹ O ₂] rx ), the main cytotoxic component in type II PDT. Experiments were performed in phantoms with the photosensitizer Photofrin and in solution using phosphorescence-based singlet oxygen luminescence dosimetry (SOLD) to validate the SOED model. Oxygen concentration and photosensitizer photobleaching versus time were measured during PDT, along with direct SOLD measurements of singlet oxygen and triplet state lifetime ( τ Δ and τ t ), for various photosensitizer concentrations to determine necessary photophysical parameters. SOLD-determined cumulative [¹ O ₂] rx was compared to SOED-calculated [¹ O ₂] rx for various photosensitizer concentrations to show a clear correlation between the two methods. This illustrates that explicit dosimetry can be used when phosphorescence-based dosimetry is not feasible. Using SOED modeling, we have also shown evidence that SOLD-measured [¹ O ₂] rx using a 523 nm pulsed laser can be used to correlate to singlet oxygen generated by a 630 nm laser during a clinical malignant pleural mesothelioma (MPM) PDT protocol by using a conversion formula.

  19. Who by accident? The social morphology of car accidents.

    PubMed

    Factor, Roni; Yair, Gad; Mahalel, David

    2010-09-01

    Prior studies in the sociology of accidents have shown that different social groups have different rates of accident involvement. This study extends those studies by implementing Bourdieu's relational perspective of social space to systematically explore the homology between drivers' social characteristics and their involvement in specific types of motor vehicle accident. Using a large database that merges official Israeli road-accident records with socioeconomic data from two censuses, this research maps the social order of road accidents through multiple correspondence analysis. Extending prior studies, the results show that different social groups indeed tend to be involved in motor vehicle accidents of different types and severity. For example, we find that drivers from low socioeconomic backgrounds are overinvolved in severe accidents with fatal outcomes. The new findings reported here shed light on the social regularity of road accidents and expose new facets in the social organization of death. © 2010 Society for Risk Analysis.

  20. 41 CFR 101-39.401 - Reporting of accidents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.4-Accidents and Claims § 101-39.401 Reporting of accidents. (a) The... manager of the GSA IFMS fleet management center issuing the vehicle; (2) The employee's supervisor; and (3... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Reporting of accidents...

  1. 49 CFR 178.337-10 - Accident damage protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Accident damage protection. 178.337-10 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.337-10 Accident damage protection. (a) All... sacrificial device must be located in the piping system outboard of the stop valve and within the accident...

  2. A comparison of the hazard perception ability of accident-involved and accident-free motorcycle riders.

    PubMed

    Cheng, Andy S K; Ng, Terry C K; Lee, Hoe C

    2011-07-01

    Hazard perception is the ability to read the road and is closely related to involvement in traffic accidents. It consists of both cognitive and behavioral components. Within the cognitive component, visual attention is an important function of driving whereas driving behavior, which represents the behavioral component, can affect the hazard perception of the driver. Motorcycle riders are the most vulnerable types of road user. The primary purpose of this study was to deepen our understanding of the correlation of different subtypes of visual attention and driving violation behaviors and their effect on hazard perception between accident-free and accident-involved motorcycle riders. Sixty-three accident-free and 46 accident-involved motorcycle riders undertook four neuropsychological tests of attention (Digit Vigilance Test, Color Trails Test-1, Color Trails Test-2, and Symbol Digit Modalities Test), filled out the Chinese Motorcycle Rider Driving Violation (CMRDV) Questionnaire, and viewed a road-user-based hazard situation with an eye-tracking system to record the response latencies to potentially dangerous traffic situations. The results showed that both the divided and selective attention of accident-involved motorcycle riders were significantly inferior to those of accident-free motorcycle riders, and that accident-involved riders exhibited significantly higher driving violation behaviors and took longer to identify hazardous situations compared to their accident-free counterparts. However, the results of the regression analysis showed that aggressive driving violation CMRDV score significantly predicted hazard perception and accident involvement of motorcycle riders. Given that all participants were mature and experienced motorcycle riders, the most plausible explanation for the differences between them is their driving style (influenced by an undesirable driving attitude), rather than skill deficits per se. The present study points to the importance of

  3. A model for calculating the costs of in vivo dosimetry and portal imaging in radiotherapy departments.

    PubMed

    Kesteloot, K; Dutreix, A; van der Schueren, E

    1993-08-01

    The costs of in vivo dosimetry and portal imaging in radiotherapy are estimated, on the basis of a detailed overview of the activities involved in both quality assurance techniques. These activities require the availability of equipment, the use of material and workload. The cost calculations allow to conclude that for most departments in vivo dosimetry with diodes will be a cheaper alternative than in vivo dosimetry with TLD-meters. Whether TLD measurements can be performed cheaper with an automatic reader (with a higher equipment cost, but lower workload) or with a semi-automatic reader (lower equipment cost, but higher workload), depends on the number of checks in the department. LSP-systems (with a very high equipment cost) as well as on-line imaging systems will be cheaper portal imaging techniques than conventional port films (with high material costs) for large departments, or for smaller departments that perform frequent volume checks.

  4. Audits for advanced treatment dosimetry

    NASA Astrophysics Data System (ADS)

    Ibbott, G. S.; Thwaites, D. I.

    2015-01-01

    Radiation therapy has advanced rapidly over the last few decades, progressing from 3D conformal treatment to image-guided intensity modulated therapy of several different flavors, both 3D and 4D and to adaptive radiotherapy. The use of intensity modulation has increased the complexity of quality assurance and essentially eliminated the physicist's ability to judge the validity of a treatment plan, even approximately, on the basis of appearance and experience. Instead, complex QA devices and procedures are required at the institutional level. Similarly, the assessment of treatment quality through remote and on-site audits also requires greater sophistication. The introduction of 3D and 4D dosimetry into external audit systems must follow, to enable quality assurance systems to perform meaningful and thorough audits.

  5. ESR dosimetry for atomic bomb survivors and radiologic technologists

    NASA Astrophysics Data System (ADS)

    Tatsumi-Miyajima, Junko

    1987-06-01

    An individual absorbed dose for atomic bomb (A-bomb) survivors and radiologic technologists has been estimated using a new personal dosimetry. This dosimetry is based on the electron spin resonance (ESR) spectroscopy of the CO 33- radicals, which are produced in their teeth by radiation. Measurements were carried out to study the characteristics of the dosimetry; the ESR signals of the CO 33- radicals were stable and increased linearly with the radiation dose. In the evaluation of the absorbed dose, the ESR signals were considered to be a function of photon energy. The absorbed doses in ten cases of A-bomb victims and eight cases of radiologic technologists were determined. For A-bomb survivors, the adsorbed doses, which were estimated using the ESR dosimetry, were consistent with the ones obtained using the calculations of the tissue dose in air of A-bomb, and also with the ones obtained using the chromosome measurements. For radiologic technologists, the absorbed doses, which were estimated using the ESR dosimetry, agreed with the ones calculated using the information on the occupational history and conditions. The advantages of this method are that the absorbed dose can be directly estimated by measuring the ESR signals obtained from the teeth of persons, who are exposed to radiation. Therefore, the ESR dosimetry is useful to estimate the accidental exposure and the long term cumulative dose.

  6. Review of U.S. Army Unmanned Aerial Systems Accident Reports: Analysis of Human Error Contributions

    DTIC Science & Technology

    2018-03-20

    USAARL Report No. 2018-08 Review of U.S. Army Unmanned Aerial Systems Accident Reports: Analysis of Human Error Contributions By Kathryn A...3 Statistical Analysis Approach ..............................................................................................3 Results...1 Introduction The success of unmanned aerial systems (UAS) operations relies upon a variety of factors, including, but not limited to

  7. Bilateral cerebrovascular accidents in incontinentia pigmenti.

    PubMed

    Fiorillo, Loretta; Sinclair, D Barry; O'Byrne, Mary L; Krol, Alfons L

    2003-07-01

    Incontinentia Pigmenti is an X-linked dominant neurocutaneous disorder with central nervous system manifestations in 30% of cases, including seizures and mental retardation. Ischemic or hemorrhagic cerebrovascular accidents have been reported rarely in incontinentia pigmenti. Chart review and literature search was performed following identification of the index case. We describe a patient with incontinentia pigmenti who developed bilateral cerebrovascular accidents in the neonatal period, with resultant severe neurologic sequelae. This is the second reported case of bilateral cerebrovascular accidents in a patient with incontinentia pigmenti. This finding may be secondary to cerebrovascular anomalies, similar to those observed in the retina. Recognition of cerebrovascular accidents as a complication of incontinentia pigmenti will hopefully lead to earlier recognition and treatment.

  8. Investigating accident causation through information network modelling.

    PubMed

    Griffin, T G C; Young, M S; Stanton, N A

    2010-02-01

    Management of risk in complex domains such as aviation relies heavily on post-event investigations, requiring complex approaches to fully understand the integration of multi-causal, multi-agent and multi-linear accident sequences. The Event Analysis of Systemic Teamwork methodology (EAST; Stanton et al. 2008) offers such an approach based on network models. In this paper, we apply EAST to a well-known aviation accident case study, highlighting communication between agents as a central theme and investigating the potential for finding agents who were key to the accident. Ultimately, this work aims to develop a new model based on distributed situation awareness (DSA) to demonstrate that the risk inherent in a complex system is dependent on the information flowing within it. By identifying key agents and information elements, we can propose proactive design strategies to optimize the flow of information and help work towards avoiding aviation accidents. Statement of Relevance: This paper introduces a novel application of an holistic methodology for understanding aviation accidents. Furthermore, it introduces an ongoing project developing a nonlinear and prospective method that centralises distributed situation awareness and communication as themes. The relevance of findings are discussed in the context of current ergonomic and aviation issues of design, training and human-system interaction.

  9. Medical dosimetry in Hungary

    NASA Astrophysics Data System (ADS)

    Turák, O.; Osvay, M.; Ballay, L.

    2012-09-01

    Radiation exposure of medical staff during cardiological and radiological procedures was investigated. The exposure of medical staff is directly connected to patient exposure. The aim of this study was to determine the distribution of doses on uncovered part of body of medical staff using LiF thermoluminescent (TL) dosimeters in seven locations. Individual Kodak film dosimeters (as authorized dosimetry system) were used for the assessment of medical staff's effective dose. Results achieved on dose distribution measurements confirm that wearing only one film badge under the lead apron does not provide enough information on the personal dose. The value of estimated annual doses on eye lens and extremities (fingers) were in good correlation with international publications.

  10. Secondary school accident reporting in one education authority.

    PubMed

    Williams, W R; Latif, A H A; Sibert, J

    2002-01-01

    Secondary schools appear to have very different accident rates when they are compared on the basis of accident report returns. The variation may be as a result of real differences in accident rates or different reporting procedures. This study investigates accident reporting from secondary schools and, in particular, the role of the school nurse. Accident form returns covering a 2-year period were collected for statistical analysis from 13 comprehensive schools in one local education authority in Wales. School sites were visited in the following school year to obtain information about accident records held on site and accident reporting procedures. The main factors determining the number of school accident reports submitted to the education authority relate to differences in recording and reporting procedures, such as the employment of a nurse and the policy of the head teacher/safety officer on submitting accident returns. Accident and emergency department referrals from similar schools may show significant differences in specific injuries and their causes. The level of school accident activity cannot be gauged from reports submitted to the education authority. Lack of incentives for collecting good accident data, in conjunction with the degree of complacency in the current system, suggest that future accident rates and reporting activity are unlikely to change.

  11. [Occupational accidents in Barcelona (Spain), from 1992 to 1993].

    PubMed

    Sampaio, R F; Martin, M; Artazcoz, L; Moncada, S

    1998-08-01

    The statistics related to labor accidents as with any other notification system ought to be the basis for programs and policies with a view to the adoption of preventive measures. In order to establish preventive norms, however, the health system needs data from researchers focussing on the dynamics of and the pitfalls revealed by specific events. Within this context the main objective of this study is to proceed with an in-depth analysis of the labor accidents verified in Barcelona (Spain) using for this purpose a descriptive statistics model to test variables such as type of accident, economic sector, economic enterprise and type of labor contract. The data source utilized was the notification system for labor accidents with grave consequences such as death of the victim registered in Barcelona during the period 1992-1993. Labor accidents registered for male workers numbered 848. A log-linear model was applied to this data base. The results show a positive association between traumatic accidents with the construction, traffic and services sectors. A positive association was also found between traumatic accidents and the size of the company concerved the small ones being the worse type in terms of worker's injuries. Regarding the nontraumatic accidents, the study showed a positive correlation between large-sized enterprises and type of temporary worker and the civil construction sector as compared to workers with long term work contracts within industry and services. There was some evidence, also, of a positive association between small and medium sized companies and temporary work and the occurrence of work accidents.

  12. CIEMAT EXTERNAL DOSIMETRY SERVICE: ISO/IEC 17025 ACCREDITATION AND 3 Y OF OPERATIONAL EXPERIENCE AS AN ACCREDITED LABORATORY.

    PubMed

    Romero, A M; Rodríguez, R; López, J L; Martín, R; Benavente, J F

    2016-09-01

    In 2008, the CIEMAT Radiation Dosimetry Service decided to implement a quality management system, in accordance with established requirements, in order to achieve ISO/IEC 17025 accreditation. Although the Service comprises the approved individual monitoring services of both external and internal radiation, this paper is specific to the actions taken by the External Dosimetry Service, including personal and environmental dosimetry laboratories, to gain accreditation and the reflections of 3 y of operational experience as an accredited laboratory. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Optical computed tomography in PRESAGE® three-dimensional dosimetry: Challenges and prospective.

    PubMed

    Khezerloo, Davood; Nedaie, Hassan Ali; Farhood, Bagher; Zirak, Alireza; Takavar, Abbas; Banaee, Nooshin; Ahmadalidokht, Isa; Kron, Tomas

    2017-01-01

    With the advent of new complex but precise radiotherapy techniques, the demands for an accurate, feasible three-dimensional (3D) dosimetry system have been increased. A 3D dosimeter system generally should not only have accurate and precise results but should also feasible, inexpensive, and time consuming. Recently, one of the new candidates for 3D dosimetry is optical computed tomography (CT) with a radiochromic dosimeter such as PRESAGE®. Several generations of optical CT have been developed since the 90s. At the same time, a large attempt has been also done to introduce the robust dosimeters that compatible with optical CT scanners. In 2004, PRESAGE® dosimeter as a new radiochromic solid plastic dosimeters was introduced. In this decade, a large number of efforts have been carried out to enhance optical scanning methods. This article attempts to review and reflect on the results of these investigations.

  14. SU-E-T-66: A Prototype for Couch Based Real-Time Dosimetry in External Beam Radiotherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ramachandran, P

    Purpose: The main purpose of this study is to design a prototype for couch-based based real time dosimetry system in external beam radiotherapy Methods: A prototype of 100 ionization chambers was designed on a printed circuit board by etching the copper layer and each ionization chamber was wired to a 50 pin connector. The signals from the two 50 pin connectors collected from the ionization chambers were then transferred to a PXI module from National Instruments. The PXI module houses a current amplifier that amplifies the charge collected from the ionization chamber. The amplified signal is then sent to amore » digital multimeter module for converting the analog signal to digital signal. A software was designed in labview to read and display the signals obtained from the PXI module. A couch attachment frame was designed to house the 100 ionization chamber module. The frame was fixed underneath the treatment couch for measuring the dose during treatment. Resutls: The ionization chamber based prototype dosimetry was tested for simple radiotherapy treatment fields and found to be a useful device for measuring real time dosimetry at the treatment couch plane. This information could be used to assess the delivered dose to a patient during radiotherapy. It could be used as an invivo dosimeter during radiotherapy. Conclusion: In this study, a prototype for couch based real time dosimetry system was designed and tested. The prototype forms a basis for the development of large scale couch based real time dosimetry system that could be used to perform morning QA prior to treatment, assess real time doses delivered to patient and as a device to monitor the output of the treatment beam. Peter MacCallum Cancer Foundation.« less

  15. In vivo thermoluminescence dosimetry for total body irradiation.

    PubMed

    Palkosková, P; Hlavata, H; Dvorák, P; Novotný, J; Novotný, J

    2002-01-01

    An improvement in the clinical results obtained using total body irradiation (TBI) with photon beams requires precise TBI treatment planning, reproducible irradiation, precise in vivo dosimetry, accurate documentation and careful evaluation. In vivo dosimetry using LiF Harshaw TLD-100 chips was used during the TBI treatments performed in our department. The results of in vivo thermoluminescence dosimetry (TLD) show that using TLD measurements and interactive adjustment of some treatment parameters based on these measurements, like monitor unit calculations, lung shielding thickness and patient positioning, it is possible to achieve high precision in absorbed dose delivery (less than 0.5%) as well as in homogeneity of irradiation (less than 6%).

  16. Fatal accident cause and conclusion.

    PubMed

    Tsach, Tsadok; Cohen, Aviva; Finegold, George

    2009-01-01

    The Toolmarks Laboratory prepared a report concerning a traffic accident involving the death of a road workman. The driver of the vehicle that hit the workman claimed that the wheels had failed to respond when turning left at a roundabout. A traffic investigator photographed the rack and pinion assembly of the steering system, which was subsequently removed and brought to the Toolmarks Laboratory. The rack and pinion assembly of the steering system was rebuilt, and examination showed that the system functioned properly. Specifically, the front wheels responded correctly to the steering input. Laboratory photographs of the steering system were taken in two different positions, from the same angles as the investigator's photographs at the scene of the accident. It was clear that the steering system had not been assembled properly in the garage.

  17. Human Factors in Cabin Accident Investigations

    NASA Technical Reports Server (NTRS)

    Chute, Rebecca D.; Rosekind, Mark R. (Technical Monitor)

    1996-01-01

    Human factors has become an integral part of the accident investigation protocol. However, much of the investigative process remains focussed on the flight deck, airframe, and power plant systems. As a consequence, little data has been collected regarding the human factors issues within and involving the cabin during an accident. Therefore, the possibility exists that contributing factors that lie within that domain may be overlooked. The FAA Office of Accident Investigation is sponsoring a two-day workshop on cabin safety accident investigation. This course, within the workshop, will be of two hours duration and will explore relevant areas of human factors research. Specifically, the three areas of discussion are: Information transfer and resource management, fatigue and other physical stressors, and the human/machine interface. Integration of these areas will be accomplished by providing a suggested checklist of specific cabin-related human factors questions for investigators to probe following an accident.

  18. Anatomy of a system accident: the crash of Avianca Flight 052.

    PubMed

    Helmreich, R L

    1994-01-01

    On January 25, 1990, Avianca Flight 052 crashed after running out of fuel following a missed approach to New York's John F. Kennedy Airport. Weather was poor on the East Coast of the United States that day, and the flight had experienced several holding patterns enroute from Medellín, Colombia, to New York. The accident is analyzed in terms of Helmreich and Foushee's (1993) model of crew performance and Reason's (1990) model of latent pathogens in system operations.

  19. Anatomy of a system accident: The crash of Avianca Flight 052

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1994-01-01

    On January 25, 1990, Avianca Flight 052 crashed after running out of fuel following a missed approach to New York's John F. Kennedy Airport. Weather was poor on the East Coast of the United States that day, and the flight had experienced several holding patterns enroute from Medellin, Colombia, to New York. The accident is analyzed in terms of Helmreich and Foushee's (1993) model of crew performance and Reason's (1990) model of latent pathogens in system operations.

  20. RCT: Module 2.04, Dosimetry, Course 8769

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hillmer, Kurt T.

    This course will introduce the types of instruments used to measure external and internal radiation to people. Dosimetry is the quantitative assessment of radiation received by the human body. Several types of dosimeters are used worldwide. This information is valuable to all radiological control personnel because dosimeters are the only direct method to measure and document personnel radiation exposure and ensure regulatory compliance with applicable limits. This course will cover dosimetry terms, Department of Energy (DOE) limits, Los Alamos National Laboratory (LANL) administrative guidelines, thermoluminescent dosimeters (TLDs), LANL dosimetry, and bioassay assessment methods. This course will prepare the student withmore » the skills necessary for radiological control technician (RCT) qualification by passing quizzes, tests, and the RCT Comprehensive Phase 1, Unit 2 Examination (TEST 27566) and providing in-thefield skills.« less

  1. EURADOS strategic research agenda: vision for dosimetry of ionising radiation

    PubMed Central

    Rühm, W.; Fantuzzi, E.; Harrison, R.; Schuhmacher, H.; Vanhavere, F.; Alves, J.; Bottollier Depois, J. F.; Fattibene, P.; Knežević, Ž.; Lopez, M. A.; Mayer, S.; Miljanić, S.; Neumaier, S.; Olko, P.; Stadtmann, H.; Tanner, R.; Woda, C.

    2016-01-01

    Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises—based on input from EURADOS Working Groups (WGs) and Voting Members—five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS website (www.eurados.org). PMID:25752758

  2. Preliminary assessment of accident-tolerant fuels on LWR performance during normal operation and under DB and BDB accident conditions

    NASA Astrophysics Data System (ADS)

    Ott, L. J.; Robb, K. R.; Wang, D.

    2014-05-01

    Following the severe accidents at the Japanese Fukushima Daiichi Nuclear Power Station in 2011, the US Department of Energy initiated research and development on the enhancement of the accident tolerance of light water reactors by the development of fuels/cladding that, in comparison with the standard UO2/Zircaloy (Zr) system, can tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operations. Analyses are presented that illustrate the impact of these new candidate fuel/cladding materials on the fuel performance at normal operating conditions and on the reactor system under DB and BDB accident conditions.

  3. Helicopter emergency medical services accident rates in different international air rescue systems

    PubMed Central

    Hinkelbein, J; Schwalbe, M; Genzwuerker, HV

    2010-01-01

    Aim Each year approximately two to four helicopter emergency medical services (HEMS) crashes occur in Germany. The aim of the present study was to compare crash rates and fatal crash rates in Germany to rates in other countries. Materials and methods A MEDLINE search from 1970 to 2009 was performed using combinations of the keywords “HEMS”, “rescue helicopter”, “accident”, “accident rate”, “crash”, and “crash rate”. The search was supplemented by additional published data. Data were compared on the basis of 10,000 missions and 100,000 helicopter flying hours. These data were allocated to specific time frames for analyis. Results Eleven relevant studies were identified. Five studies (three from Germany, one from the US, one from Australia) analyzing HEMS accidents on the basis of 10,000 missions were identified. Crash rates per 10,000 missions ranged between 0.4 and 3.05 and fatal crash rates between 0.04 and 2.12. In addition, nine studies (six from the US, two from Germany, one from Australia) used 100,000 flying hours as a denominator. Here, crash rates ranged between 1.7 and 13.4 and fatal crash rates between 0.91 and 4.7. Conclusions Data and accident rates were inhomogeneous and differed significantly. Data analysis was impeded by publication of mean data, use of different time frames, and differences in HEMS systems. PMID:27147837

  4. Ion-kill dosimetry

    NASA Technical Reports Server (NTRS)

    Katz, R.; Cucinotta, F. A.; Fromm, M.; Chambaudet, A.

    2001-01-01

    Unanticipated late effects in neutron and heavy ion therapy, not attributable to overdose, imply a qualitative difference between low and high LET therapy. We identify that difference as 'ion kill', associated with the spectrum of z/beta in the radiation field, whose measurement we label 'ion-kill dosimetry'.

  5. Retrospective dosimetry: dose evaluation using unheated and heated quartz from a radioactive waste storage building.

    PubMed

    Jain, M; Bøtter-Jensen, L; Murray, A S; Jungner, H

    2002-01-01

    In the assessment of dose received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using heated materials such as household ceramics and bricks. However, unheated materials such as mortar and concrete are more commonly found in industrial sites and particularly in nuclear installations. These materials contain natural dosemeters such as quartz, which usually is less sensitive than its heated counterpart. The potential of quartz extracted from mortar in a wall of a low-level radioactive-waste storage facility containing distributed sources of 60Co and 137Cs has been investigated. Dose-depth proliles based on small aliquots and single grains from the quartz extracted from the mortar samples are reported here. These are compared with results from heated quartz and polymineral fine grains extracted from an adjacent brick, and the integrated dose recorded by environmental TLDs.

  6. 76 FR 55079 - Recreational Vessel Accident Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-06

    ... Accident Reporting AGENCY: Coast Guard, DHS. ACTION: Notice of Advisory Committee recommendations; request for additional public comments. SUMMARY: The Coast Guard has received recommendations from the... system for boating accidents; and (2) take steps to clarify what, how, and when information is reported...

  7. Traffic Accidents Involving Cyclists Identifying Causal Factors Using Questionnaire Survey, Traffic Accident Data, and Real-World Observation.

    PubMed

    Oikawa, Shoko; Hirose, Toshiya; Aomura, Shigeru; Matsui, Yasuhiro

    2016-11-01

    The purpose of this study is to clarify the mechanism of traffic accidents involving cyclists. The focus is on the characteristics of cyclist accidents and scenarios, because the number of traffic accidents involving cyclists in Tokyo is the highest in Japan. First, dangerous situations in traffic incidents were investigated by collecting data from 304 cyclists in one city in Tokyo using a questionnaire survey. The survey indicated that cyclists used their bicycles generally while commuting to work or school in the morning. Second, the study investigated the characteristics of 250 accident situations involving cyclists that happened in the city using real-world bicycle accident data. The results revealed that the traffic accidents occurred at intersections of local streets, where cyclists collided most often with vehicles during commute time in the morning. Third, cyclists' behavior was observed at a local street intersection in the morning in the city using video pictures. In one hour during the morning commute period, 250 bicycles passed through the intersection. The results indicated that one of the reasons for traffic accidents involving cyclists might be the combined effect of low visibility, caused by the presence of box-like building structures close to the intersections, and the cyclists' behavior in terms of their velocity and no confirming safety. It was observed that, on average, bicycle velocity was 3.1 m/s at the initial line of an intersection. The findings from this study could be useful in developing new technologies to improve cyclist safety, such as alert devices for cyclists and vehicle drivers, wireless communication systems between cyclists and vehicle drivers, or advanced vehicles with bicycle detection and collision mitigation systems.

  8. Dosimetry audits and intercomparisons in radiotherapy: A Malaysian profile

    NASA Astrophysics Data System (ADS)

    M. Noor, Noramaliza; Nisbet, A.; Hussein, M.; Chu S, Sarene; Kadni, T.; Abdullah, N.; Bradley, D. A.

    2017-11-01

    Quality audits and intercomparisons are important in ensuring control of processes in any system of endeavour. Present interest is in control of dosimetry in teletherapy, there being a need to assess the extent to which there is consistent radiation dose delivery to the patient. In this study we review significant factors that impact upon radiotherapy dosimetry, focusing upon the example situation of radiotherapy delivery in Malaysia, examining existing literature in support of such efforts. A number of recommendations are made to provide for increased quality assurance and control. In addition to this study, the first level of intercomparison audit i.e. measuring beam output under reference conditions at eight selected Malaysian radiotherapy centres is checked; use being made of 9 μm core diameter Ge-doped silica fibres (Ge-9 μm). The results of Malaysian Secondary Standard Dosimetry Laboratory (SSDL) participation in the IAEA/WHO TLD postal dose audit services during the period between 2011 and 2015 will also been discussed. In conclusion, following review of the development of dosimetry audits and the conduct of one such exercise in Malaysia, it is apparent that regular periodic radiotherapy audits and intercomparison programmes should be strongly supported and implemented worldwide. The programmes to-date demonstrate these to be a good indicator of errors and of consistency between centres. A total of ei+ght beams have been checked in eight Malaysian radiotherapy centres. One out of the eight beams checked produced an unacceptable deviation; this was found to be due to unfamiliarity with the irradiation procedures. Prior to a repeat measurement, the mean ratio of measured to quoted dose was found to be 0.99 with standard deviation of 3%. Subsequent to the repeat measurement, the mean distribution was 1.00, and the standard deviation was 1.3%.

  9. Preliminary Modeling of Accident Tolerant Fuel Concepts under Accident Conditions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gamble, Kyle A.; Hales, Jason D.

    2016-12-01

    The catastrophic events that occurred at the Fukushima-Daiichi nuclear power plant in 2011 have led to widespread interest in research of alternative fuels and claddings that are proposed to be accident tolerant. Thus, the United States Department of Energy through its NEAMS (Nuclear Energy Advanced Modeling and Simulation) program has funded an Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The ATF HIP is funded for a three-year period. The purpose of the HIP is to perform research into two potential accident tolerant concepts and provide an in-depth report to the Advanced Fuels Campaign (AFC) describing the behavior of themore » concepts, both of which are being considered for inclusion in a lead test assembly scheduled for placement into a commercial reactor in 2022. The initial focus of the HIP is on uranium silicide fuel and iron-chromium-aluminum (FeCrAl) alloy cladding. Utilizing the expertise of three national laboratory participants (INL, LANL, and ANL) a comprehensive mulitscale approach to modeling is being used including atomistic modeling, molecular dynamics, rate theory, phase-field, and fuel performance simulations. In this paper, we present simulations of two proposed accident tolerant fuel systems: U3Si2 fuel with Zircaloy-4 cladding, and UO2 fuel with FeCrAl cladding. The simulations investigate the fuel performance response of the proposed ATF systems under Loss of Coolant and Station Blackout conditions using the BISON code. Sensitivity analyses are completed using Sandia National Laboratories’ DAKOTA software to determine which input parameters (e.g., fuel specific heat) have the greatest influence on the output metrics of interest (e.g., fuel centerline temperature). Early results indicate that each concept has significant advantages as well as areas of concern. Further work is required prior to formulating the proposition report for the Advanced Fuels Campaign.« less

  10. 75 FR 49869 - Changes to Standard Numbering System, Vessel Identification System, and Boating Accident Report...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ... Boating Accident Report Database AGENCY: Coast Guard, DHS. ACTION: Reopening of public comment period... Boating Accident Report Database. DATES: Comments and related material must either be submitted to our... Database that, collectively, are intended to improve recreational boating safety efforts, enhance law...

  11. The Fukushima radiation accident: consequences for radiation accident medical management.

    PubMed

    Meineke, Viktor; Dörr, Harald

    2012-08-01

    The March 2011 radiation accident in Fukushima, Japan, is a textbook example of a radiation accident of global significance. In view of the global dimensions of the accident, it is important to consider the lessons learned. In this context, emphasis must be placed on consequences for planning appropriate medical management for radiation accidents including, for example, estimates of necessary human and material resources. The specific characteristics of the radiation accident in Fukushima are thematically divided into five groups: the exceptional environmental influences on the Fukushima radiation accident, particular circumstances of the accident, differences in risk perception, changed psychosocial factors in the age of the Internet and globalization, and the ignorance of the effects of ionizing radiation both among the general public and health care professionals. Conclusions like the need for reviewing international communication, interfacing, and interface definitions will be drawn from the Fukushima radiation accident.

  12. APT Blanket System Loss-of-Coolant Accident (LOCA) Based on Initial Conceptual Design - Case 2: with Beam Shutdown Only

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hamm, L.L.

    1998-10-07

    This report is one of a series of reports that document normal operation and accident simulations for the Accelerator Production of Tritium (APT) blanket heat removal system. These simulations were performed for the Preliminary Safety Analysis Report. This report documents the results of simulations of a Loss-of-Flow Accident (LOFA) where power is lost to all of the pumps that circulate water in the blanket region, the accelerator beam is shut off and neither the residual heat removal nor cavity flood systems operate.

  13. 77 FR 18689 - Changes to Standard Numbering System, Vessel Identification System, and Boating Accident Report...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ... requires States to compile and send us reports, information, and statistics on casualties reported to them... data and statistical information received from the current collection to establish National... accident prevention programs; and publish accident statistics in accordance with Title 46 U.S.C. 6102...

  14. Dosimetry audit simulation of treatment planning system in multicenters radiotherapy

    NASA Astrophysics Data System (ADS)

    Kasmuri, S.; Pawiro, S. A.

    2017-07-01

    Treatment Planning System (TPS) is an important modality that determines radiotherapy outcome. TPS requires input data obtained through commissioning and the potentially error occurred. Error in this stage may result in the systematic error. The aim of this study to verify the TPS dosimetry to know deviation range between calculated and measurement dose. This study used CIRS phantom 002LFC representing the human thorax and simulated all external beam radiotherapy stages. The phantom was scanned using CT Scanner and planned 8 test cases that were similar to those in clinical practice situation were made, tested in four radiotherapy centers. Dose measurement using 0.6 cc ionization chamber. The results of this study showed that generally, deviation of all test cases in four centers was within agreement criteria with average deviation about -0.17±1.59 %, -1.64±1.92 %, 0.34±1.34 % and 0.13±1.81 %. The conclusion of this study was all TPS involved in this study showed good performance. The superposition algorithm showed rather poor performance than either analytic anisotropic algorithm (AAA) and convolution algorithm with average deviation about -1.64±1.92 %, -0.17±1.59 % and -0.27±1.51 % respectively.

  15. Feasibility study of superconducting power cables for DC electric railway feeding systems in view of thermal condition at short circuit accident

    NASA Astrophysics Data System (ADS)

    Kumagai, Daisuke; Ohsaki, Hiroyuki; Tomita, Masaru

    2016-12-01

    A superconducting power cable has merits of a high power transmission capacity, transmission losses reduction, a compactness, etc., therefore, we have been studying the feasibility of applying superconducting power cables to DC electric railway feeding systems. However, a superconducting power cable is required to be cooled down and kept at a very low temperature, so it is important to reveal its thermal and cooling characteristics. In this study, electric circuit analysis models of the system and thermal analysis models of superconducting cables were constructed and the system behaviors were simulated. We analyzed the heat generation by a short circuit accident and transient temperature distribution of the cable to estimate the value of temperature rise and the time required from the accident. From these results, we discussed a feasibility of superconducting cables for DC electric railway feeding systems. The results showed that the short circuit accident had little impact on the thermal condition of a superconducting cable in the installed system.

  16. Major Accidents (Gray Swans) Likelihood Modeling Using Accident Precursors and Approximate Reasoning.

    PubMed

    Khakzad, Nima; Khan, Faisal; Amyotte, Paul

    2015-07-01

    Compared to the remarkable progress in risk analysis of normal accidents, the risk analysis of major accidents has not been so well-established, partly due to the complexity of such accidents and partly due to low probabilities involved. The issue of low probabilities normally arises from the scarcity of major accidents' relevant data since such accidents are few and far between. In this work, knowing that major accidents are frequently preceded by accident precursors, a novel precursor-based methodology has been developed for likelihood modeling of major accidents in critical infrastructures based on a unique combination of accident precursor data, information theory, and approximate reasoning. For this purpose, we have introduced an innovative application of information analysis to identify the most informative near accident of a major accident. The observed data of the near accident were then used to establish predictive scenarios to foresee the occurrence of the major accident. We verified the methodology using offshore blowouts in the Gulf of Mexico, and then demonstrated its application to dam breaches in the United Sates. © 2015 Society for Risk Analysis.

  17. Interferometric optical online dosimetry for selective retina treatment (SRT)

    NASA Astrophysics Data System (ADS)

    Stoehr, Hardo; Ptaszynski, Lars; Fritz, Andreas; Brinkmann, Ralf

    2007-07-01

    Selective retina treatment (SRT) is a new laser based method to treat retinal diseases associated with disorders of the retinal pigment epithelium (RPE). Applying microsecond laser pulses tissue damage spatially confined to the retinal pigment epithelium (RPE) is achieved. The RPE cell damage is caused by transient microbubbles emerging at the strongly absorbing melanin granules inside the RPE cells. Due to the spatial confinement to the RPE the photoreceptors can be spared and vision can be maintained in the treated retinal areas. A drawback for effective clinical SRT is that the laser induced lesions are ophthalmoscopically invisible. Therefore, a real-time feedback system for dosimetry is necessary in order to avoid undertreatment or unwanted collateral damage to the adjacent tissue. We develop a dosimetry system which uses optical interferometry for the detection of the transient microbubbles. The system is based on an optical fiber interferometer operated with a laser diode at 830nm. We present current results obtained with a laser slit lamp using porcine RPE explants in vitro and complete porcine eye globes ex vivo. The RPE cell damage is determined by Calcein fluorescence viability assays. With a threshold criterium for RPE cell death derived from the measured interferometric signal transients good agreement with the results of the viability assays is achieved.

  18. Domino effect in chemical accidents: main features and accident sequences.

    PubMed

    Darbra, R M; Palacios, Adriana; Casal, Joaquim

    2010-11-15

    The main features of domino accidents in process/storage plants and in the transportation of hazardous materials were studied through an analysis of 225 accidents involving this effect. Data on these accidents, which occurred after 1961, were taken from several sources. Aspects analyzed included the accident scenario, the type of accident, the materials involved, the causes and consequences and the most common accident sequences. The analysis showed that the most frequent causes are external events (31%) and mechanical failure (29%). Storage areas (35%) and process plants (28%) are by far the most common settings for domino accidents. Eighty-nine per cent of the accidents involved flammable materials, the most frequent of which was LPG. The domino effect sequences were analyzed using relative probability event trees. The most frequent sequences were explosion→fire (27.6%), fire→explosion (27.5%) and fire→fire (17.8%). Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Scenario analysis of freight vehicle accident risks in Taiwan.

    PubMed

    Tsai, Ming-Chih; Su, Chien-Chih

    2004-07-01

    This study develops a quantitative risk model by utilizing Generalized Linear Interactive Model (GLIM) to analyze the major freight vehicle accidents in Taiwan. Eight scenarios are established by interacting three categorical variables of driver ages, vehicle types and road types, each of which contains two levels. The database that consists of 2043 major accidents occurring between 1994 and 1998 in Taiwan is utilized to fit and calibrate the model parameters. The empirical results indicate that accident rates of freight vehicles in Taiwan were high in the scenarios involving trucks and non-freeway systems, while; accident consequences were severe in the scenarios involving mature drivers or non-freeway systems. Empirical evidences also show that there is no significant relationship between accident rates and accident consequences. This is to stress that safety studies that describe risk merely as accident rates rather than the combination of accident rates and consequences by definition might lead to biased risk perceptions. Finally, the study recommends using number of vehicle as an alternative of traffic exposure in commercial vehicle risk analysis. The merits of this would be that it is simple and thus reliable; meanwhile, the resulted risk that is termed as fatalities per vehicle could provide clear and direct policy implications for insurance practices and safety regulations.

  20. 48 CFR 1252.223-71 - Accident and fire reporting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....223-71 Accident and fire reporting. As prescribed in (TAR) 48 CFR 1223.7000(a), insert the following clause: Accident and Fire Reporting (APR 2005) (a) The Contractor shall report to the Contracting Officer... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Accident and fire...

  1. 48 CFR 1252.223-71 - Accident and fire reporting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....223-71 Accident and fire reporting. As prescribed in (TAR) 48 CFR 1223.7000(a), insert the following clause: Accident and Fire Reporting (APR 2005) (a) The Contractor shall report to the Contracting Officer... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Accident and fire...

  2. 48 CFR 1252.223-71 - Accident and fire reporting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....223-71 Accident and fire reporting. As prescribed in (TAR) 48 CFR 1223.7000(a), insert the following clause: Accident and Fire Reporting (APR 2005) (a) The Contractor shall report to the Contracting Officer... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Accident and fire...

  3. 48 CFR 1252.223-71 - Accident and fire reporting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....223-71 Accident and fire reporting. As prescribed in (TAR) 48 CFR 1223.7000(a), insert the following clause: Accident and Fire Reporting (APR 2005) (a) The Contractor shall report to the Contracting Officer... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Accident and fire...

  4. 48 CFR 1252.223-71 - Accident and fire reporting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....223-71 Accident and fire reporting. As prescribed in (TAR) 48 CFR 1223.7000(a), insert the following clause: Accident and Fire Reporting (APR 2005) (a) The Contractor shall report to the Contracting Officer... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Accident and fire...

  5. Calibration facility for environment dosimetry instruments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bercea, Sorin; Celarel, Aurelia; Cenusa, Constantin

    2013-12-16

    In the last ten years, the nuclear activities, as well as the major nuclear events (see Fukushima accident) had an increasing impact on the environment, merely by contamination with radioactive materials. The most conferment way to quickly identify the presence of some radioactive elements in the environment, is to measure the dose-equivalent rate H. In this situation, information concerning the values of H due only to the natural radiation background must exist. Usually, the values of H due to the natural radiation background, are very low (∼10{sup −9} - 10{sup −8} Sv/h). A correct measurement of H in this rangemore » involve a performing calibration of the measuring instruments in the measuring range corresponding to the natural radiation background lead to important problems due to the presence of the natural background itself the best way to overlap this difficulty is to set up the calibration stand in an area with very low natural radiation background. In Romania, we identified an area with such special conditions at 200 m dept, in a salt mine. This paper deals with the necessary requirements for such a calibration facility, as well as with the calibration stand itself. The paper includes also, a description of the calibration stand (and images) as well as the radiological and metrological parameters. This calibration facilities for environment dosimetry is one of the few laboratories in this field in Europe.« less

  6. Characterization of MOSFET detectors for in vivo dosimetry in interventional radiology and for dose reconstruction in case of overexposure.

    PubMed

    Bassinet, Céline; Huet, Christelle; Baumann, Marion; Etard, Cécile; Réhel, Jean-Luc; Boisserie, Gilbert; Debroas, Jacques; Aubert, Bernard; Clairand, Isabelle

    2013-04-01

    As MOSFET (Metal Oxide Semiconductor Field Effect Transistor) detectors allow dose measurements in real time, the interest in these dosimeters is growing. The aim of this study was to investigate the dosimetric properties of commercially available TN-502RD-H MOSFET silicon detectors (Best Medical Canada, Ottawa, Canada) in order to use them for in vivo dosimetry in interventional radiology and for dose reconstruction in case of overexposure. Reproducibility of the measurements, dose rate dependence, and dose response of the MOSFET detectors have been studied with a Co source. Influence of the dose rate, frequency, and pulse duration on MOSFET responses has also been studied in pulsed x-ray fields. Finally, in order to validate the integrated dose given by MOSFET detectors, MOSFETs and TLDs (LiF:Mg,Cu,P) were fixed on an Alderson-Rando phantom in the conditions of an interventional neuroradiology procedure, and their responses have been compared. The results of this study show the suitability of MOSFET detectors for in vivo dosimetry in interventional radiology and for dose reconstruction in case of accident, provided a well-corrected energy dependence, a pulse duration equal to or higher than 10 ms, and an optimized contact between the detector and the skin of the patient are achieved.

  7. Relationship between student selection criteria and learner success for medical dosimetry students

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baker, Jamie, E-mail: jabaker@mdanderson.org; Tucker, Debra; Raynes, Edilberto

    Medical dosimetry education occupies a specialized branch of allied health higher education. Noted international shortages of health care workers, reduced university funding, limitations on faculty staffing, trends in learner attrition, and increased enrollment of nontraditional students force medical dosimetry educational leadership to reevaluate current admission practices. Program officials wish to select medical dosimetry students with the best chances of successful graduation. The purpose of the quantitative ex post facto correlation study was to investigate the relationship between applicant characteristics (cumulative undergraduate grade point average (GPA), science grade point average (SGPA), prior experience as a radiation therapist, and previous academic degrees)more » and the successful completion of a medical dosimetry program, as measured by graduation. A key finding from the quantitative study was the statistically significant positive correlation between a student's previous degree and his or her successful graduation from the medical dosimetry program. Future research investigations could include a larger research sample, representative of more medical dosimetry student populations, and additional studies concerning the relationship of previous work as a radiation therapist and the effect on success as a medical dosimetry student. Based on the quantitative correlation analysis, medical dosimetry leadership on admissions committees could revise student selection rubrics to place less emphasis on an applicant's undergraduate cumulative GPA and increase the weight assigned to previous degrees.« less

  8. Deployment of the DosiKit System Under Operational Conditions: Experience From a French Defense National Nuclear Exercise.

    PubMed

    Entine, F; Bensimon Etzol, J; Bettencourt, C; Dondey, M; Michel, X; Gagna, G; Gellie, G; Corre, Y; Ugolin, N; Chevillard, S; Amabile, J-C

    2018-07-01

    Estimation of the dose received by accidentally irradiated victims is based on a tripod: clinical, biological, and physical dosimetry. The DosiKit system is an operational and mobile biodosimetry device allowing the measurement of external irradiation directly on the site of a radiological accident. This tool is based on capillary blood sample and hair follicle collection. The aim is to obtain a whole-body and local-surface dose assessment. This paper is about the technical evaluation of the DosiKit; the analytical process and scientific validation are briefly described. The Toulon exercise scenario was based on a major accident involving the reactor of a nuclear attack submarine. The design of the scenario made it impossible for several players (firefighters, medical team) to leave the area for a long time, and they were potentially exposed to high dose rates. The DosiKit system was fully integrated into a deployable radiological emergency laboratory, and the response to operational needs was very satisfactory.

  9. Learning lessons from Natech accidents - the eNATECH accident database

    NASA Astrophysics Data System (ADS)

    Krausmann, Elisabeth; Girgin, Serkan

    2016-04-01

    When natural hazards impact industrial facilities that house or process hazardous materials, fires, explosions and toxic releases can occur. This type of accident is commonly referred to as Natech accident. In order to prevent the recurrence of accidents or to better mitigate their consequences, lessons-learned type studies using available accident data are usually carried out. Through post-accident analysis, conclusions can be drawn on the most common damage and failure modes and hazmat release paths, particularly vulnerable storage and process equipment, and the hazardous materials most commonly involved in these types of accidents. These analyses also lend themselves to identifying technical and organisational risk-reduction measures that require improvement or are missing. Industrial accident databases are commonly used for retrieving sets of Natech accident case histories for further analysis. These databases contain accident data from the open literature, government authorities or in-company sources. The quality of reported information is not uniform and exhibits different levels of detail and accuracy. This is due to the difficulty of finding qualified information sources, especially in situations where accident reporting by the industry or by authorities is not compulsory, e.g. when spill quantities are below the reporting threshold. Data collection has then to rely on voluntary record keeping often by non-experts. The level of detail is particularly non-uniform for Natech accident data depending on whether the consequences of the Natech event were major or minor, and whether comprehensive information was available for reporting. In addition to the reporting bias towards high-consequence events, industrial accident databases frequently lack information on the severity of the triggering natural hazard, as well as on failure modes that led to the hazmat release. This makes it difficult to reconstruct the dynamics of the accident and renders the development of

  10. ISD3: a particokinetic model for predicting the combined effects of particle sedimentation, diffusion and dissolution on cellular dosimetry for in vitro systems.

    PubMed

    Thomas, Dennis G; Smith, Jordan N; Thrall, Brian D; Baer, Donald R; Jolley, Hadley; Munusamy, Prabhakaran; Kodali, Vamsi; Demokritou, Philip; Cohen, Joel; Teeguarden, Justin G

    2018-01-25

    The development of particokinetic models describing the delivery of insoluble or poorly soluble nanoparticles to cells in liquid cell culture systems has improved the basis for dose-response analysis, hazard ranking from high-throughput systems, and now allows for translation of exposures across in vitro and in vivo test systems. Complimentary particokinetic models that address processes controlling delivery of both particles and released ions to cells, and the influence of particle size changes from dissolution on particle delivery for cell-culture systems would help advance our understanding of the role of particles and ion dosimetry on cellular toxicology. We developed ISD3, an extension of our previously published model for insoluble particles, by deriving a specific formulation of the Population Balance Equation for soluble particles. ISD3 describes the time, concentration and particle size dependent dissolution of particles, their delivery to cells, and the delivery and uptake of ions to cells in in vitro liquid test systems. We applied the model to calculate the particle and ion dosimetry of nanosilver and silver ions in vitro after calibration of two empirical models, one for particle dissolution and one for ion uptake. Total media ion concentration, particle concentration and total cell-associated silver time-courses were well described by the model, across 2 concentrations of 20 and 110 nm particles. ISD3 was calibrated to dissolution data for 20 nm particles as a function of serum protein concentration, but successfully described the media and cell dosimetry time-course for both particles at all concentrations and time points. We also report the finding that protein content in media affects the initial rate of dissolution and the resulting near-steady state ion concentration in solution for the systems we have studied. By combining experiments and modeling, we were able to quantify the influence of proteins on silver particle solubility, determine the

  11. Circuit board accident--organizational dimension hidden by prescribed safety.

    PubMed

    de Almeida, Ildeberto Muniz; Buoso, Eduardo; do Amaral Dias, Maria Dionísia; Vilela, Rodolfo Andrade Gouveia

    2012-01-01

    This study analyzes an accident in which two maintenance workers suffered severe burns while replacing a circuit breaker panel in a steel mill, following model of analysis and prevention of accidents (MAPA) developed with the objective of enlarging the perimeter of interventions and contributing to deconstruction of blame attribution practices. The study was based on materials produced by a health service team in an in-depth analysis of the accident. The analysis shows that decisions related to system modernization were taken without considering their implications in maintenance scheduling and creating conflicts of priorities and of interests between production and safety; and also reveals that the lack of a systemic perspective in safety management was its principal failure. To explain the accident as merely non-fulfillment of idealized formal safety rules feeds practices of blame attribution supported by alibi norms and inhibits possible prevention. In contrast, accident analyses undertaken in worker health surveillance services show potential to reveal origins of these events incubated in the history of the system ignored in practices guided by the traditional paradigm.

  12. Student Perceptions of an Online Medical Dosimetry Program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lenards, Nishele, E-mail: lenards.nish@uwlax.ed

    2011-07-01

    The University of Wisconsin-La Crosse offers the first online medical dosimetry program in the nation. There is no data to research a program of this type. This research consisted of the evaluation of other distance education programs including health profession programs in addition to face-to-face medical dosimetry programs. There was a need to collect and analyze student perceptions of online learning in medical dosimetry. This research provided a guide for future implementation by other programs as well as validated the University of Wisconsin-La Crosse program. Methodology used consisted of an electronic survey sent to all previous and currently enrolled studentsmore » in the University of Wisconsin-La Crosse medical dosimetry program. The survey was both quantitative and qualitative in demonstrating attitudinal perceptions of students in the program. Quantitative data was collected and analyzed using a 5-point Likert scale. Qualitative data was gathered based on the open-ended responses and the identifying themes from the responses. The results demonstrated an overall satisfaction with this program, the instructor, and the online courses. Students felt a sense of belonging to the courses and the program. Considering that a majority of the students had never taken an online course previously, the students felt there were no technology issues. Future research should include an evaluation of board exam statistics for students enrolled in the online and face-to-face medical dosimetry programs.« less

  13. ISDD: A computational model of particle sedimentation, diffusion and target cell dosimetry for in vitro toxicity studies

    PubMed Central

    2010-01-01

    Background The difficulty of directly measuring cellular dose is a significant obstacle to application of target tissue dosimetry for nanoparticle and microparticle toxicity assessment, particularly for in vitro systems. As a consequence, the target tissue paradigm for dosimetry and hazard assessment of nanoparticles has largely been ignored in favor of using metrics of exposure (e.g. μg particle/mL culture medium, particle surface area/mL, particle number/mL). We have developed a computational model of solution particokinetics (sedimentation, diffusion) and dosimetry for non-interacting spherical particles and their agglomerates in monolayer cell culture systems. Particle transport to cells is calculated by simultaneous solution of Stokes Law (sedimentation) and the Stokes-Einstein equation (diffusion). Results The In vitro Sedimentation, Diffusion and Dosimetry model (ISDD) was tested against measured transport rates or cellular doses for multiple sizes of polystyrene spheres (20-1100 nm), 35 nm amorphous silica, and large agglomerates of 30 nm iron oxide particles. Overall, without adjusting any parameters, model predicted cellular doses were in close agreement with the experimental data, differing from as little as 5% to as much as three-fold, but in most cases approximately two-fold, within the limits of the accuracy of the measurement systems. Applying the model, we generalize the effects of particle size, particle density, agglomeration state and agglomerate characteristics on target cell dosimetry in vitro. Conclusions Our results confirm our hypothesis that for liquid-based in vitro systems, the dose-rates and target cell doses for all particles are not equal; they can vary significantly, in direct contrast to the assumption of dose-equivalency implicit in the use of mass-based media concentrations as metrics of exposure for dose-response assessment. The difference between equivalent nominal media concentration exposures on a μg/mL basis and target cell

  14. [Accidents on Iceland's most dangerous roads].

    PubMed

    Bjarnason, Thóroddur; Arnarsson, Sveinn

    2012-02-01

    The objective of this paper was to identify the most dangerous segments of the Icelandic road system in terms of the number of accidents pr km and the rate of accidents pr million km travelled. First to identify the segments where the number of accidents is highest and where the risk of the individual traveller is the greatest. Second to evaluate if the association between the number and the rate of accidents is positive or negative. Third to identify the road segments that are the most dangerous in the sense of many accidents and great risk to individual travellers. Main roads outside urban centers were divided into 45 segments that were on average 78 km in length. Infrequently travelled roads and roads within urban centers were omitted. Information on the length of roads, traffic density and number of accidents was used to calculate the number of accidents per km and the rate of accidents per million km travelled. The correlation between the number and rate of accidents was calculated and the most dangerous road segments were identified by the average rank order on both dimensions. Most accidents pr km occurred on the main roads to and from the capital region, but also east towards Hvolsvöllur, north towards Akureyri and in the Mideast region of the country. The rate of accidents pr million km travelled was highest in the northeast region, in northern Snæfellsnes and in the Westfjords. The most dangerous roads on both dimensions were in Mideast, northern Westfjords, in the north between Blönduós and Akureyri and in northern Snæfellsnes. Most accidents pr km occurred on roads with a low accident rate pr million km travelled. It is therefore possible to reduce accidents the most by increasing road safety where it is already the greatest but that would however increase inequalities in road safety. Policy development in transportation is therefore in part a question of priorities in healthcare. Individual equality in safety and health are not always fully

  15. EURADOS strategic research agenda: vision for dosimetry of ionising radiation.

    PubMed

    Rühm, W; Fantuzzi, E; Harrison, R; Schuhmacher, H; Vanhavere, F; Alves, J; Bottollier Depois, J F; Fattibene, P; Knežević, Ž; Lopez, M A; Mayer, S; Miljanić, S; Neumaier, S; Olko, P; Stadtmann, H; Tanner, R; Woda, C

    2016-02-01

    Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises-based on input from EURADOS Working Groups (WGs) and Voting Members-five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS website (www.eurados.org). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Two-dimensional dosimetry of radiotherapeutical proton beams using thermoluminescence foils.

    PubMed

    Czopyk, L; Klosowski, M; Olko, P; Swakon, J; Waligorski, M P R; Kajdrowicz, T; Cuttone, G; Cirrone, G A P; Di Rosa, F

    2007-01-01

    In modern radiation therapy such as intensity modulated radiation therapy or proton therapy, one is able to cover the target volume with improved dose conformation and to spare surrounding tissue with help of modern measurement techniques. Novel thermoluminescence dosimetry (TLD) foils, developed from the hot-pressed mixture of LiF:Mg,Cu,P (MCP TL) powder and ethylene-tetrafluoroethylene (ETFE) copolymer, have been applied for 2-D dosimetry of radiotherapeutical proton beams at INFN Catania and IFJ Krakow. A TLD reader with 70 mm heating plate and CCD camera was used to read the 2-D emission pattern of irradiated foils. The absorbed dose profiles were evaluated, taking into account correction factors specific for TLD such as dose and energy response. TLD foils were applied for measuring of dose distributions within an eye phantom and compared with predictions obtained from the MCNPX code and Eclipse Ocular Proton Planning (Varian Medical Systems) clinical radiotherapy planning system. We demonstrate the possibility of measuring 2-D dose distributions with point resolution of about 0.5 x 0.5 mm(2).

  17. Injury protection and accident causation parameters for vulnerable road users based on German In-Depth Accident Study GIDAS.

    PubMed

    Otte, Dietmar; Jänsch, Michael; Haasper, Carl

    2012-01-01

    Within a study of accident data from GIDAS (German In-Depth Accident Study), vulnerable road users are investigated regarding injury risk in traffic accidents. GIDAS is the largest in-depth accident study in Germany. Due to a well-defined sampling plan, representativeness with respect to the federal statistics is also guaranteed. A hierarchical system ACASS (Accident Causation Analysis with Seven Steps) was developed in GIDAS, describing the human causation factors in a chronological sequence. The accordingly classified causation factors - derived from the systematic of the analysis of human accident causes ("7 steps") - can be used to describe the influence of accident causes on the injury outcome. The bases of the study are accident documentations over ten years from 1999 to 2008 with 8204 vulnerable road users (VRU), of which 3 different groups were selected as pedestrians n=2041, motorcyclists n=2199 and bicyclists n=3964, and analyzed on collisions with cars and trucks as well as vulnerable road users alone. The paper will give a description of the injury pattern and injury mechanisms of accidents. The injury frequencies and severities are pointed out considering different types of VRU and protective measures of helmet and clothes of the human body. The impact points are demonstrated on the car, following to conclusion of protective measures on the vehicle. Existing standards of protection devices as well as interdisciplinary research, including accident and injury statistics, are described. With this paper, a summarization of the existing possibilities on protective measures for pedestrians, bicyclists and motorcyclists is given and discussed by comparison of all three groups of vulnerable road users. Also the relevance of special impact situations and accident causes mainly responsible for severe injuries are pointed out, given the new orientation of research for the avoidance and reduction of accident patterns. 2010 Elsevier Ltd. All rights reserved.

  18. Radiation monitoring systems as a tool for assessment of accidental releases at the Chernobyl and Fukushima NPPs

    NASA Astrophysics Data System (ADS)

    Shershakov, Vjacheslav; Bulgakov, Vladimir

    2013-04-01

    approach was used for assessing the consequences at the Fukushima NPP. These results are also provided in the presentation. References 1. Kelly G.N., Ehrhardt J., Shershakov V.M.. Decision Support for Off-Site Emergency Preparedness in Europe. Radiation Protection Dosimetry, Vol. 64 Nos. 1-2, 1996, pp. 129-142. 2. Ehrhardt J., Shershakov V.M. Real-time on-line decision support systems (RODOS) for off-site emergency management following a nuclear accident. EUR 16533, 1996 3. Kelly G.N., Shershakov V.M. (Editors). Environmental contamination, radiation doses and health consequences after the ?hernobyl accident. Radiation Protection Dosimetry. Special Commemorative Issue.Vol. 64, 1996 4. Shershakov V.M. Computer information technology for support of radiation monitoring problems. OECD Proceedings of an International Workshop «Nuclear Emergency Data Management», Zurich, Switzerland, 1998, pp. 377-388 5. Pitkevich V.A., Duba V.V., Ivanov V.K., Tsyb A.F., Shershakov V.M., Golubenkov A.V., Borodin R.V., V.A., Kosykh V.S. Reconstruction of External Dose to the Inhabitants Living in the Contaminated Territory of Russia by the Results of the Accident at the Chernobyl NPP. Health Phys., Vol. 30, No. 1, pp. 54-68, 1995. 6. Shershakov V., Fesenko S., Kryshev I., Semioshkina T. Decision-Aiding Tools for Remediation Strategies. In: Radioactivity in the Environment, Volume 14, Remediation of Contaminated Environments, 2009, pp 41- 120, Elsevier Ltd.

  19. Human error analysis of commercial aviation accidents: application of the Human Factors Analysis and Classification system (HFACS).

    PubMed

    Wiegmann, D A; Shappell, S A

    2001-11-01

    The Human Factors Analysis and Classification System (HFACS) is a general human error framework originally developed and tested within the U.S. military as a tool for investigating and analyzing the human causes of aviation accidents. Based on Reason's (1990) model of latent and active failures, HFACS addresses human error at all levels of the system, including the condition of aircrew and organizational factors. The purpose of the present study was to assess the utility of the HFACS framework as an error analysis and classification tool outside the military. The HFACS framework was used to analyze human error data associated with aircrew-related commercial aviation accidents that occurred between January 1990 and December 1996 using database records maintained by the NTSB and the FAA. Investigators were able to reliably accommodate all the human causal factors associated with the commercial aviation accidents examined in this study using the HFACS system. In addition, the classification of data using HFACS highlighted several critical safety issues in need of intervention research. These results demonstrate that the HFACS framework can be a viable tool for use within the civil aviation arena. However, additional research is needed to examine its applicability to areas outside the flight deck, such as aircraft maintenance and air traffic control domains.

  20. Multichannel film dosimetry with nonuniformity correction.

    PubMed

    Micke, Andre; Lewis, David F; Yu, Xiang

    2011-05-01

    A new method to evaluate radiochromic film dosimetry data scanned in multiple color channels is presented. This work was undertaken to demonstrate that the multichannel method is fundamentally superior to the traditional single channel method. The multichannel method allows for the separation and removal of the nondose-dependent portions of a film image leaving a residual image that is dependent only on absorbed dose. Radiochromic films were exposed to 10 x 10 cm radiation fields (Co-60 and 6 MV) at doses up to about 300 cGy. The films were scanned in red-blue-green (RGB) format on a flatbed color scanner and measured to build calibration tables relating the absorbed dose to the response of the film in each of the color channels. Film images were converted to dose maps using two methods. The first method used the response from a single color channel and the second method used the response from all three color channels. The multichannel method allows for the separation of the scanned signal into one part that is dose-dependent and another part that is dose-independent and enables the correction of a variety of disturbances in the digitized image including nonuniformities in the active coating on the radiochromic film as well as scanner related artifacts. The fundamental mathematics of the two methods is described and the dose maps calculated from film images using the two methods are compared and analyzed. The multichannel dosimetry method was shown to be an effective way to separate out non-dose-dependent abnormalities from radiochromic dosimetry film images. The process was shown to remove disturbances in the scanned images caused by nonhomogeneity of the radiochromic film and artifacts caused by the scanner and to improve the integrity of the dose information. Multichannel dosimetry also reduces random noise in the dose images and mitigates scanner-related artifacts such as lateral position dependence. In providing an ability to calculate dose maps from data in

  1. An assessment of a 3D EPID-based dosimetry system using conventional two- and three-dimensional detectors for VMAT.

    PubMed

    Stevens, S; Dvorak, P; Spevacek, V; Pilarova, K; Bray-Parry, M; Gesner, J; Richmond, A

    2018-01-01

    To provide a 3D dosimetric evaluation of a commercial portal dosimetry system using 2D/3D detectors under ideal conditions using VMAT. A 2D ion chamber array, radiochromic film and gel dosimeter were utilised to provide a dosimetric evaluation of transit phantom and pre-treatment 'fluence' EPID back-projected dose distributions for a standard VMAT plan. In-house 2D and 3D gamma methods compared pass statistics relative to each dosimeter and TPS dose distributions. Fluence mode and transit EPID dose distributions back-projected onto phantom geometry produced 2D gamma pass rates in excess of 97% relative to other tested detectors and exported TPS dose planes when a 3%, 3 mm global gamma criterion was applied. Use of a gel dosimeter within a glass vial allowed comparison of measured 3D dose distributions versus EPID 3D dose and TPS calculated distributions. 3D gamma comparisons between modalities at 3%, 3 mm gave pass rates in excess of 92%. Use of fluence mode was indicative of transit results under ideal conditions with slightly reduced dose definition. 3D EPID back projected dose distributions were validated against detectors in both 2D and 3D. Cross validation of transit dose delivered to a patient is limited due to reasons of practicality and the tests presented are recommended as a guideline for 3D EPID dosimetry commissioning; allowing direct comparison between detector, TPS, fluence and transit modes. The results indicate achievable gamma scores for a complex VMAT plan in a homogenous phantom geometry and contributes to growing experience of 3D EPID dosimetry. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  2. Midair collisions - The accidents, the systems, and the Realpolitik

    NASA Technical Reports Server (NTRS)

    Wiener, E. L.

    1980-01-01

    Two midair collisions occurring in 1978 are described, and the air traffic control system and procedures in use at the time, human factors implications and political consequences of the accidents are examined. The first collision occurred in Memphis and involved a Falcon jet and a Cessna 150 in a situation in which the controllers handling each aircraft were not aware of the presence of the other aircraft until it was too late. The second occurred in San Diego four months later, when a Boeing 727 on a visual approach struck a Cessna 172 from the rear. Following the San Diego collision there arose a great deal of investigative activity, resulting in suggestions for tighter control on visual flight rules aircraft and the expansion of positive control airspace. These issues then led to a political battle involving general aviation, the FAA and the Congress. It is argued, however, that the collisions were in fact system-induced errors resulting from an air traffic control system which emphasizes airspace allocation and politics rather than the various human factors problems facing pilots and controllers.

  3. Micro-Fabricated Solid-State Radiation Detectors for Active Personal Dosimetry

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.; Chen, Liang-Yu

    2007-01-01

    Active radiation dosimetry is important to human health and equipment functionality for space applications outside the protective environment of a space station or vehicle. This is especially true for long duration missions to the moon, where the lack of a magnetic field offers no protection from space radiation to those on extravehicular activities. In order to improve functionality, durability and reliability of radiation dosimeters for future NASA lunar missions, single crystal silicon carbide devices and scintillating fiber detectors are currently being investigated for applications in advanced extravehicular systems. For many years, NASA Glenn Research Center has led significant efforts in silicon carbide semiconductor technology research and instrumentation research for sensor applications under extreme conditions. This report summarizes the technical progress and accomplishments toward characterization of radiation-sensing components for the recommendation of their fitness for advanced dosimetry development.

  4. Absorbed dose to water based dosimetry versus air kerma based dosimetry for high-energy photon beams: an experimental study.

    PubMed

    Palmans, Hugo; Nafaa, Laila; De, Jans Jo; Gillis, Sofie; Hoornaert, Marie-Thérèse; Martens, Chantal; Piessens, Marleen; Thierens, Hubert; Van der Plaetsen, Ann; Vynckier, Stefaan

    2002-02-07

    In recent years, a change has been proposed from air kerma based reference dosimetry to absorbed dose based reference dosimetry for all radiotherapy beams of ionizing radiation. In this paper, a dosimetry study is presented in which absorbed dose based dosimetry using recently developed formalisms was compared with air kerma based dosimetry using older formalisms. Three ionization chambers of each of three different types were calibrated in terms of absorbed dose to water and air kerma and sent to five hospitals. There, reference dosimetry with all the chambers was performed in a total of eight high-energy clinical photon beams. The selected chamber types were the NE2571, the PTW-30004 and the Wellhöfer-FC65G (previously Wellhöfer-IC70). Having a graphite wall, they exhibit a stable volume and the presence of an aluminium electrode ensures the robustness of these chambers. The data were analysed with the most important recommendations for clinical dosimetry: IAEA TRS-398, AAPM TG-51, IAEA TRS-277, NCS report-2 (presently recommended in Belgium) and AAPM TG-21. The necessary conversion factors were taken from those protocols, or calculated using the data in the different protocols if data for a chamber type are lacking. Polarity corrections were within 0.1% for all chambers in all beams. Recombination corrections were consistent with theoretical predictions, did not vary within a chamber type and only slightly between different chamber types. The maximum chamber-to-chamber variations of the dose obtained with the different formalisms within the same chamber type were between 0.2% and 0.6% for the NE2571, between 0.2% and 0.6% for the PTW-30004 and 0.1% and 0.3% for the Wellhöfer-FC65G for the different beams. The absorbed dose results for the NE2571 and Wellhöfer-FC65G chambers were in good agreement for all beams and all formalisms. The PTW-30004 chambers gave a small but systematically higher result compared to the result for the NE2571 chambers (on the

  5. On the use of unshielded cables in ionization chamber dosimetry for total-skin electron therapy.

    PubMed

    Chen, Z; Agostinelli, A; Nath, R

    1998-03-01

    's spatial configuration were altered during the two-polarity measurements. This suggests that automatic scanning systems with unshielded cables should not be used in TSET ionization chamber dosimetry. However, the data did show that an unshielded cable may be used in TSET ionization chamber dosimetry if the size of cable-induced error in a given TSET beam is pre-evaluated and the measurement is carefully conducted. When such an evaluation has not been performed, additional shielding should be applied to the cable being used, making measurements at multiple points difficult.

  6. Radiation dosimetry for quality control of food preservation and disinfestation

    NASA Astrophysics Data System (ADS)

    McLaughlin, W. L.; Miller, A.; Uribe, R. M.

    In the use of x and gamma rays and scanned electron beams to extend the shelf life of food by delay of sprouting and ripening, killing of microbes, and control of insect population, quality assurance is provided by standardized radiation dosimetry. By strategic placement of calibrated dosimeters that are sufficiently stable and reproducible, it is possible to monitor minimum and maximum radiation absorbed dose levels and dose uniformity for a given processed foodstuff. The dosimetry procedure is especially important in the commisioning of a process and in making adjustments of process parameters (e.g. conveyor speed) to meet changes that occur in product and source parameters (e.g. bulk density and radiation spectrum). Routine dosimetry methods and certain corrections of dosimetry data may be selected for the radiations used in typical food processes.

  7. Relationship between student selection criteria and learner success for medical dosimetry students.

    PubMed

    Baker, Jamie; Tucker, Debra; Raynes, Edilberto; Aitken, Florence; Allen, Pamela

    2016-01-01

    Medical dosimetry education occupies a specialized branch of allied health higher education. Noted international shortages of health care workers, reduced university funding, limitations on faculty staffing, trends in learner attrition, and increased enrollment of nontraditional students force medical dosimetry educational leadership to reevaluate current admission practices. Program officials wish to select medical dosimetry students with the best chances of successful graduation. The purpose of the quantitative ex post facto correlation study was to investigate the relationship between applicant characteristics (cumulative undergraduate grade point average (GPA), science grade point average (SGPA), prior experience as a radiation therapist, and previous academic degrees) and the successful completion of a medical dosimetry program, as measured by graduation. A key finding from the quantitative study was the statistically significant positive correlation between a student׳s previous degree and his or her successful graduation from the medical dosimetry program. Future research investigations could include a larger research sample, representative of more medical dosimetry student populations, and additional studies concerning the relationship of previous work as a radiation therapist and the effect on success as a medical dosimetry student. Based on the quantitative correlation analysis, medical dosimetry leadership on admissions committees could revise student selection rubrics to place less emphasis on an applicant׳s undergraduate cumulative GPA and increase the weight assigned to previous degrees. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  8. Developing of an automation for therapy dosimetry systems by using labview software

    NASA Astrophysics Data System (ADS)

    Aydin, Selim; Kam, Erol

    2018-06-01

    Traceability, accuracy and consistency of radiation measurements are essential in radiation dosimetry, particularly in radiotherapy, where the outcome of treatments is highly dependent on the radiation dose delivered to patients. Therefore it is very important to provide reliable, accurate and fast calibration services for therapy dosimeters since the radiation dose delivered to a radiotherapy patient is directly related to accuracy and reliability of these devices. In this study, we report the performance of in-house developed computer controlled data acquisition and monitoring software for the commercially available radiation therapy electrometers. LabVIEW® software suite is used to provide reliable, fast and accurate calibration services. The software also collects environmental data such as temperature, pressure and humidity in order to use to use these them in correction factor calculations. By using this software tool, a better control over the calibration process is achieved and the need for human intervention is reduced. This is the first software that can control frequently used dosimeter systems, in radiation thereapy field at hospitals, such as Unidos Webline, Unidos E, Dose-1 and PC Electrometers.

  9. Factors Affecting Road Traffic Accident in Batu Pahat, Johor, Malaysia

    NASA Astrophysics Data System (ADS)

    Che-Him, Norziha; Roslan, Rozaini; Saifullah Rusiman, Mohd; Khalid, Kamil; Ghazali Kamardan, M.; Azbi Arobi, Farquis; Mohamad, Nazeera

    2018-04-01

    A road traffic accident resulted from the combination of factors related to the few components of the system involving environment, roads, road users, vehicles and the interaction between those systems. Road traffic accident (RTA) in Malaysia recorded as the highest fatality rate (per 100,000 population) among the ASEAN countries. In 2016, more than half of million cases accident recorded with more than 7,000 people were killed. Therefore, the RTA is one of the most critical issue in Malaysia even become the worldwide burden to authority. Generally, driving is a complex process which involves movement of a vehicle by either a computer or human controller. However, failure to control and coordinate will contribute to an accident. The objective of this study is to identify the pattern of accident in Johor Malaysia and to examine the relationship between the number of accident and the types of vehicles and roads. The results could help the government to recognise the different patterns, types of vehicles and roads that show major factors in the increasing of road traffic accident in Malaysia.

  10. Benchmarking MARS (accident management software) with the Browns Ferry fire

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dawson, S.M.; Liu, L.Y.; Raines, J.C.

    1992-01-01

    The MAAP Accident Response System (MARS) is a userfriendly computer software developed to provide management and engineering staff with the most needed insights, during actual or simulated accidents, of the current and future conditions of the plant based on current plant data and its trends. To demonstrate the reliability of the MARS code in simulatng a plant transient, MARS is being benchmarked with the available reactor pressure vessel (RPV) pressure and level data from the Browns Ferry fire. The MRS software uses the Modular Accident Analysis Program (MAAP) code as its basis to calculate plant response under accident conditions. MARSmore » uses a limited set of plant data to initialize and track the accidnt progression. To perform this benchmark, a simulated set of plant data was constructed based on actual report data containing the information necessary to initialize MARS and keep track of plant system status throughout the accident progression. The initial Browns Ferry fire data were produced by performing a MAAP run to simulate the accident. The remaining accident simulation used actual plant data.« less

  11. Development of multivariate exposure and fatal accident involvement rates for 1977

    DOT National Transportation Integrated Search

    1985-10-01

    The need for multivariate accident involvement rates is often encounted in : accident analysis. The FARS (Fatal Accident Reporting System) files contain : records of fatal involvements characterized by many variables while NPTS : (National Personal T...

  12. Jerky driving--An indicator of accident proneness?

    PubMed

    Bagdadi, Omar; Várhelyi, András

    2011-07-01

    This study uses continuously logged driving data from 166 private cars to derive the level of jerks caused by the drivers during everyday driving. The number of critical jerks found in the data is analysed and compared with the self-reported accident involvement of the drivers. The results show that the expected number of accidents for a driver increases with the number of critical jerks caused by the driver. Jerk analyses make it possible to identify safety critical driving behaviour or "accident prone" drivers. They also facilitate the development of safety measures such as active safety systems or advanced driver assistance systems, ADAS, which could be adapted for specific groups of drivers or specific risky driving behaviour. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Road accidents and business cycles in Spain.

    PubMed

    Rodríguez-López, Jesús; Marrero, Gustavo A; González, Rosa Marina; Leal-Linares, Teresa

    2016-11-01

    This paper explores the causes behind the downturn in road accidents in Spain across the last decade. Possible causes are grouped into three categories: Institutional factors (a Penalty Point System, PPS, dating from 2006), technological factors (active safety and passive safety of vehicles), and macroeconomic factors (the Great recession starting in 2008, and an increase in fuel prices during the spring of 2008). The PPS has been blessed by incumbent authorities as responsible for the decline of road fatalities in Spain. Using cointegration techniques, the GDP growth rate, the fuel price, the PPS, and technological items embedded in motor vehicles appear to be statistically significantly related with accidents. Importantly, PPS is found to be significant in reducing fatal accidents. However, PPS is not significant for non-fatal accidents. In view of these results, we conclude that road accidents in Spain are very sensitive to the business cycle, and that the PPS influenced the severity (fatality) rather than the quantity of accidents in Spain. Importantly, technological items help explain a sizable fraction in accidents downturn, their effects dating back from the end of the nineties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Evaluating accident rates on Virginia's secondary road system.

    DOT National Transportation Integrated Search

    1973-01-01

    In order to establish priorities for allocating highway funds available for safety improvements, an investigation was made of a method for ranking the state's counties according to their accident histories. Million vehicle miles traveled, registered ...

  15. A study of general aviation accidents involving children in 2011.

    PubMed

    Poland, Kristin M; Marshall, Nora M

    2014-08-01

    General aviation accidents involving children are rare, but when they do happen, little is known about the children involved, including their age, restraint status, and injuries. This lack of information is due to the fact that the National Transportation Safety Board (NTSB) did not always collect detailed data about passengers involved in accidents. Consequently, in 2011, NTSB investigators collected detailed information on children involved in general aviation accidents and this report provides a summary of the outcomes. During 2011, 19 general aviation accidents and incidents included 39 children who were 14 yr old and younger. In total, 26 children sustained fatal injuries, 2 sustained serious injuries, 5 sustained minor injuries, and 6 sustained no injuries. All of the children less than 2 yr old were restrained in a child restraint system and sustained no injuries in the accidents. At least one 4-yr-old child would have benefited from being restrained in a child restraint system. In addition, in two accidents, it was determined that children were likely sharing a single seat belt. This year-long data collection regarding children involved in general aviation accidents provided substantial information concerning age, restraint status, and injuries. In response to issues identified, the NTSB made improvements to its aviation data management system to routinely collect this information for future investigations and enable subsequent evaluation of the data regarding child passengers involved in general aviation accidents over the long term.

  16. Development of a patient-specific dosimetry estimation system in nuclear medicine examination

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lin, H. H.; Dong, S. L.; Yang, H. J.

    2011-07-01

    The purpose of this study is to develop a patient-specific dosimetry estimation system in nuclear medicine examination using a SimSET-based Monte Carlo code. We added a dose deposition routine to store the deposited energy of the photons during their flights in SimSET and developed a user-friendly interface for reading PET and CT images. Dose calculated on ORNL phantom was used to validate the accuracy of this system. The S values for {sup 99m}Tc, {sup 18}F and {sup 131}I obtained by the system were compared to those from the MCNP4C code and OLINDA. The ratios of S values computed by thismore » system to those obtained with OLINDA for various organs were ranged from 0.93 to 1.18, which are comparable to that obtained from MCNP4C code (0.94 to 1.20). The average ratios of S value were 0.99{+-}0.04, 1.03{+-}0.05, and 1.00{+-}0.07 for isotopes {sup 131}I, {sup 18}F, and {sup 99m}Tc, respectively. The simulation time of SimSET was two times faster than MCNP4C's for various isotopes. A 3D dose calculation was also performed on a patient data set with PET/CT examination using this system. Results from the patient data showed that the estimated S values using this system differed slightly from those of OLINDA for ORNL phantom. In conclusion, this system can generate patient-specific dose distribution and display the isodose curves on top of the anatomic structure through a friendly graphic user interface. It may also provide a useful tool to establish an appropriate dose-reduction strategy to patients in nuclear medicine environments. (authors)« less

  17. Radiation dosimetry with fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Avino, S.; D'Avino, V.; Giorgini, A.; Pacelli, R.; Liuzzi, R.; Cella, L.; Gagliardi, G.; De Natale, P.

    2014-05-01

    The measurement and monitoring of radiation dose delivered in patient tissues is a critical aspect in radiation therapy. Various dosimeters have proven effective in measuring radiations at low doses. However, there is a growing demand for new dosimeters based on small, non-invasive and high resolution devices. Here we report on a miniature dosimeter based on an optical fiber cavity. We demonstrate an ultimate detection limit of 160 mGy with an effective interaction region of 6 x 10-4 mm3. Due to its reliability, compactness and biomedical dose level sensitivity, our system shows itself suitable for applications in radiation therapy dosimetry.

  18. Accident Data Use and Geographic Information System (GIS)

    DOT National Transportation Integrated Search

    1998-09-16

    Project Description: The Cheyenne Area Transportation Planning Process (ChATTP) : has developed a PowerPoint presentation demonstrating how to use an existing : accident database with GIS software. The slides are followed by a hands-on : demonstratio...

  19. How feasible is remote 3D dosimetry for MR guided Radiation Therapy (MRgRT)?

    NASA Astrophysics Data System (ADS)

    Mein, S.; Rankine, L.; Miles, D.; Juang, T.; Cai, B.; Curcuru, A.; Mutic, S.; Fenoli, J.; Adamovics, J.; Li, H.; Oldham, M.

    2017-05-01

    To develop and apply a remote dosimetry protocol with PRESAGE® radiochromic plastic and optical-CT readout in the validation of MRI guided radiation therapy (MRgRT) treatments (MRIdian® by ViewRay®). Through multi-institutional collaboration we performed PRESAGE® dosimetry studies in 4ml cuvettes to investigate dose-response linearity, MR-compatibility, and energy-independence. An open calibration field and symmetrical 3-field plans were delivered to 10cm diameter PRESAGE® to examine percent depth dose and response uniformity under a magnetic field. Evidence of non-linear dose response led to a large volume PRESAGE® study where small corrections were developed for temporally- and spatially-dependent behaviors observed between irradiation and delayed readout. TG-119 plans were created in the MRIdian® TPS and then delivered to 14.5cm 2kg PRESAGE® dosimeters. Through the domestic investigation of an off-site MRgRT system, a refined 3D remote dosimetry protocol is presented capable of validation of advanced MRgRT radiation treatments.

  20. Professional experience and traffic accidents/near-miss accidents among truck drivers.

    PubMed

    Girotto, Edmarlon; Andrade, Selma Maffei de; González, Alberto Durán; Mesas, Arthur Eumann

    2016-10-01

    To investigate the relationship between the time working as a truck driver and the report of involvement in traffic accidents or near-miss accidents. A cross-sectional study was performed with truck drivers transporting products from the Brazilian grain harvest to the Port of Paranaguá, Paraná, Brazil. The drivers were interviewed regarding sociodemographic characteristics, working conditions, behavior in traffic and involvement in accidents or near-miss accidents in the previous 12 months. Subsequently, the participants answered a self-applied questionnaire on substance use. The time of professional experience as drivers was categorized in tertiles. Statistical analyses were performed through the construction of models adjusted by multinomial regression to assess the relationship between the length of experience as a truck driver and the involvement in accidents or near-miss accidents. This study included 665 male drivers with an average age of 42.2 (±11.1) years. Among them, 7.2% and 41.7% of the drivers reported involvement in accidents and near-miss accidents, respectively. In fully adjusted analysis, the 3rd tertile of professional experience (>22years) was shown to be inversely associated with involvement in accidents (odds ratio [OR] 0.29; 95% confidence interval [CI] 0.16-0.52) and near-miss accidents (OR 0.17; 95% CI 0.05-0.53). The 2nd tertile of professional experience (11-22 years) was inversely associated with involvement in accidents (OR 0.63; 95% CI 0.40-0.98). An evident relationship was observed between longer professional experience and a reduction in reporting involvement in accidents and near-miss accidents, regardless of age, substance use, working conditions and behavior in traffic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Workshop report on atomic bomb dosimetry-residual radiation exposure: recent research and suggestions for future studies.

    PubMed

    Kerr, George D; Egbert, Stephen D; Al-Nabulsi, Isaf; Beck, Harold L; Cullings, Harry M; Endo, Satoru; Hoshi, Masaharu; Imanaka, Tetsuji; Kaul, Dean C; Maruyama, Satoshi; Reeves, Glen I; Ruehm, Werner; Sakaguchi, Aya; Simon, Steven L; Spriggs, Gregory D; Stram, Daniel O; Tonda, Tetsuji; Weiss, Joseph F; Weitz, Ronald L; Young, Robert W

    2013-08-01

    There is a need for accurate dosimetry for studies of health effects in the Japanese atomic bomb survivors because of the important role that these studies play in worldwide radiation protection standards. International experts have developed dosimetry systems, such as the Dosimetry System 2002 (DS02), which assess the initial radiation exposure to gamma rays and neutrons but only briefly consider the possibility of some minimal contribution to the total body dose by residual radiation exposure. In recognition of the need for an up-to-date review of the topic of residual radiation exposure in Hiroshima and Nagasaki, recently reported studies were reviewed at a technical session at the 57th Annual Meeting of the Health Physics Society in Sacramento, California, 22-26 July 2012. A one-day workshop was also held to provide time for detailed discussion of these newer studies and to evaluate their potential use in clarifying the residual radiation exposures to the atomic-bomb survivors at Hiroshima and Nagasaki. Suggestions for possible future studies are also included in this workshop report.

  2. Workshop Report on Atomic Bomb Dosimetry--Residual Radiation Exposure: Recent Research and Suggestions for Future Studies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2013-06-06

    There is a need for accurate dosimetry for studies of health effects in the Japanese atomic bomb survivors because of the important role that these studies play in worldwide radiation protection standards. International experts have developed dosimetry systems, such as the Dosimetry System 2002 (DS02), which assess the initial radiation exposure to gamma rays and neutrons but only briefly consider the possibility of some minimal contribution to the total body dose by residual radiation exposure. In recognition of the need for an up-to-date review of the topic of residual radiation exposure in Hiroshima and Nagasaki, recently reported studies were reviewedmore » at a technical session at the 57th Annual Meeting of the Health Physics Society in Sacramento, California, 22-26 July 2012. A one-day workshop was also held to provide time for detailed discussion of these newer studies and to evaluate their potential use in clarifying the residual radiation exposures to the atomic-bomb survivors at Hiroshima and Nagasaki. Suggestions for possible future studies are also included in this workshop report.« less

  3. Road accidents caused by drivers falling asleep.

    PubMed

    Sagberg, F

    1999-11-01

    preceding such accidents may give a better background for implementing effective driver warning systems and other countermeasures.

  4. Allometric scaling and accidents at work

    PubMed Central

    Cempel, Czesław; Tabaszewski, Maciej; Ordysiński, Szymon

    2016-01-01

    Allometry is the knowledge concerning relations between the features of some beings, like animals, or cities. For example, the daily energy rate is proportional to a mass of mammals rise of 3/4. This way of thinking has spread quickly from biology to many areas of research concerned with sociotechnical systems. It was revealed that the number of innovations, patents or heavy crimes rises as social interaction increases in a bigger city, while other urban indexes such as suicides decrease with social interaction. Enterprise is also a sociotechnical system, where social interaction and accidents at work take place. Therefore, do these interactions increase the number of accidents at work or, on the contrary, are they reduction-driving components? This article tries to catch such links and assess the allometric exponent between the number of accidents at work and the number of employees in an enterprise. PMID:26655044

  5. Analysis of accidents in nine Iranian gas refineries: 2007-2011.

    PubMed

    Mehrdad, R; Bolouri, A; Shakibmanesh, A R

    2013-10-01

    Occupational accidents are one of the major health hazards in industries and associated with high mortality, morbidity, spiritual damage and economic losses in the world. To determine the incidence of occupational accidents in 9 Iranian gas refineries between March 2007 and February 2011. Data on all occupational accidents occurred between March 2007 and February 2011, as well as other possible associated variables including time of accident, whether the accident was due to a personal or systemic fault, type of accident and its outcomes, age and gender of the victim, the injured parts of the body, job experience, and type of employment, were extracted from HSE reports and notes of health care services. Based on these data, we calculated the incidence rate of accidents and assessed the associated factors. During the 5 studied years, 1129 accidents have been recorded. The incidence of fatal accidents was 1.64 per 100 000 and of nonfatal accidents was 1857 per 100 000 workers per year. 99.4% of injured workers were male. The mean±SD age of injured people was 29.6±7.3 years. Almost 70% of injured workers aged under 30 years. The mean±SD job experience was 5.3±5.3 years. Accidents occurred more commonly around 10:00. More than 60% of accidents happened between 8:00 and 15:00. July had the highest incidence rate. The most common type of accident was being struck by an object (48%). More than 94% of accidents are caused by personal rather than systemic faults. Hands and wrists were the most common injured parts and involved in more than one-third of accidents. 70% of injured workers needed medical treatment and returned to work after primary treatment. The pattern of occupational accidents in Iranian gas refineries is similar to other previous reports in many ways. The incidence did not change significantly over the study period. Establishment of an online network for precise registration, notification and meticulous data collection seems necessary.

  6. Field monitoring versus individual miner dosimetry of radon daughter products in mines.

    PubMed

    Domański, T; Kluszczyński, D; Olszewski, J; Chruscielewski, W

    1989-01-01

    The paper presents the results realised simultaneously by two different and independent systems of measurement of an assessment of miners' exposure to radon daughter products which naturally occur in the air of mines. The first one, called the Air Sampling System (ASS), was based on the field monitoring of radon progeny in air, the second one, called the Individual Dosimetry System (IDS), was based on the individual dosimeters worn by miners. Experimental comparison of these two systems has been conducted for six years in eleven Polish underground metal-ore mines. This study reveals that no correlation exists between the concentration and annual miners' exposures evaluated by the ASS and IDS. The ratio ASS/IDS for mine population varies from 11.0 to 0.14 in respect of annual concentration means, and in respect to annual exposures, this ratio varies from 4.5 to 0.14. The conclusion to be drawn from six years' observation and comparison of both systems is that correct and true evaluation of miners' exposure to radon progeny can be made only by the use of the Individual Dosimetry System, since the Air Sampling System is too sensitive and too dependent on the Strategy of sampling and its radiation.

  7. Designing the accident and emergency system: lessons from manufacturing

    PubMed Central

    Walley, P

    2003-01-01

    Objectives: To review the literature on manufacturing process design and demonstrate applicability in health care. Methods: Literature review and application of theory using two years activity data from two healthcare communities and extensive observation of activities over a six week period by seven researchers. Results: It was possible to identify patient flows that could be used to design treatment processes around the needs of the patient. Some queues are built into existing treatment processes and can be removed by better process design. Capacity imbalance, not capacity shortage, causes some unnecessary waiting in accident and emergency departments. Conclusions: Clinicians would find that modern manufacturing theories produce more acceptable designs of systems. In particular, good quality is seen as a necessary pre-requisite of fast, efficient services. PMID:12642523

  8. Designing the accident and emergency system: lessons from manufacturing.

    PubMed

    Walley, P

    2003-03-01

    To review the literature on manufacturing process design and demonstrate applicability in health care. Literature review and application of theory using two years activity data from two healthcare communities and extensive observation of activities over a six week period by seven researchers. It was possible to identify patient flows that could be used to design treatment processes around the needs of the patient. Some queues are built into existing treatment processes and can be removed by better process design. Capacity imbalance, not capacity shortage, causes some unnecessary waiting in accident and emergency departments. Clinicians would find that modern manufacturing theories produce more acceptable designs of systems. In particular, good quality is seen as a necessary pre-requisite of fast, efficient services.

  9. Human error analysis of commercial aviation accidents using the human factors analysis and classification system (HFACS)

    DOT National Transportation Integrated Search

    2001-02-01

    The Human Factors Analysis and Classification System (HFACS) is a general human error framework : originally developed and tested within the U.S. military as a tool for investigating and analyzing the human : causes of aviation accidents. Based upon ...

  10. Comparison of calculated beta- and gamma-ray doses after the Fukushima accident with data from single-grain luminescence retrospective dosimetry of quartz inclusions in a brick sample

    PubMed Central

    Endo, Satoru; Fujii, Keisuke; Kajimoto, Tsuyoshi; Tanaka, Kenichi; Stepanenko, Valeriy; Kolyzhenkov, Timofey; Petukhov, Aleksey; Akhmedova, Umukusum; Bogacheva, Viktoriia

    2018-01-01

    Abstract To estimate the beta- and gamma-ray doses in a brick sample taken from Odaka, Minami-Soma City, Fukushima Prefecture, Japan, a Monte Carlo calculation was performed with Particle and Heavy Ion Transport code System (PHITS) code. The calculated results were compared with data obtained by single-grain retrospective luminescence dosimetry of quartz inclusions in the brick sample. The calculated result agreed well with the measured data. The dose increase measured at the brick surface was explained by the beta-ray contribution, and the slight slope in the dose profile deeper in the brick was due to the gamma-ray contribution. The skin dose was estimated from the calculated result as 164 mGy over 3 years at the sampling site. PMID:29385528

  11. Comparison of calculated beta- and gamma-ray doses after the Fukushima accident with data from single-grain luminescence retrospective dosimetry of quartz inclusions in a brick sample.

    PubMed

    Endo, Satoru; Fujii, Keisuke; Kajimoto, Tsuyoshi; Tanaka, Kenichi; Stepanenko, Valeriy; Kolyzhenkov, Timofey; Petukhov, Aleksey; Akhmedova, Umukusum; Bogacheva, Viktoriia

    2018-05-01

    To estimate the beta- and gamma-ray doses in a brick sample taken from Odaka, Minami-Soma City, Fukushima Prefecture, Japan, a Monte Carlo calculation was performed with Particle and Heavy Ion Transport code System (PHITS) code. The calculated results were compared with data obtained by single-grain retrospective luminescence dosimetry of quartz inclusions in the brick sample. The calculated result agreed well with the measured data. The dose increase measured at the brick surface was explained by the beta-ray contribution, and the slight slope in the dose profile deeper in the brick was due to the gamma-ray contribution. The skin dose was estimated from the calculated result as 164 mGy over 3 years at the sampling site.

  12. Evaluation Metrics Applied to Accident Tolerant Fuels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shannon M. Bragg-Sitton; Jon Carmack; Frank Goldner

    2014-10-01

    The safe, reliable, and economic operation of the nation’s nuclear power reactor fleet has always been a top priority for the United States’ nuclear industry. Continual improvement of technology, including advanced materials and nuclear fuels, remains central to the industry’s success. Decades of research combined with continual operation have produced steady advancements in technology and have yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. One of the current missions of the U.S. Department of Energy’s (DOE) Office of Nuclear Energy (NE) is to develop nuclear fuelsmore » and claddings with enhanced accident tolerance for use in the current fleet of commercial LWRs or in reactor concepts with design certifications (GEN-III+). Accident tolerance became a focus within advanced LWR research upon direction from Congress following the 2011 Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex. The overall goal of ATF development is to identify alternative fuel system technologies to further enhance the safety, competitiveness and economics of commercial nuclear power. Enhanced accident tolerant fuels would endure loss of active cooling in the reactor core for a considerably longer period of time than the current fuel system while maintaining or improving performance during normal operations. The U.S. DOE is supporting multiple teams to investigate a number of technologies that may improve fuel system response and behavior in accident conditions, with team leadership provided by DOE national laboratories, universities, and the nuclear industry. Concepts under consideration offer both evolutionary and revolutionary changes to the current nuclear fuel system. Mature concepts will be tested in the Advanced Test Reactor at Idaho National Laboratory beginning in Summer 2014 with additional concepts

  13. A Quality Assurance Method that Utilizes 3D Dosimetry and Facilitates Clinical Interpretation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Oldham, Mark, E-mail: mark.oldham@duke.edu; Thomas, Andrew; O'Daniel, Jennifer

    2012-10-01

    Purpose: To demonstrate a new three-dimensional (3D) quality assurance (QA) method that provides comprehensive dosimetry verification and facilitates evaluation of the clinical significance of QA data acquired in a phantom. Also to apply the method to investigate the dosimetric efficacy of base-of-skull (BOS) intensity-modulated radiotherapy (IMRT) treatment. Methods and Materials: Two types of IMRT QA verification plans were created for 6 patients who received BOS IMRT. The first plan enabled conventional 2D planar IMRT QA using the Varian portal dosimetry system. The second plan enabled 3D verification using an anthropomorphic head phantom. In the latter, the 3D dose distribution wasmore » measured using the DLOS/Presage dosimetry system (DLOS = Duke Large-field-of-view Optical-CT System, Presage Heuris Pharma, Skillman, NJ), which yielded isotropic 2-mm data throughout the treated volume. In a novel step, measured 3D dose distributions were transformed back to the patient's CT to enable calculation of dose-volume histograms (DVH) and dose overlays. Measured and planned patient DVHs were compared to investigate clinical significance. Results: Close agreement between measured and calculated dose distributions was observed for all 6 cases. For gamma criteria of 3%, 2 mm, the mean passing rate for portal dosimetry was 96.8% (range, 92.0%-98.9%), compared to 94.9% (range, 90.1%-98.9%) for 3D. There was no clear correlation between 2D and 3D passing rates. Planned and measured dose distributions were evaluated on the patient's anatomy, using DVH and dose overlays. Minor deviations were detected, and the clinical significance of these are presented and discussed. Conclusions: Two advantages accrue to the methods presented here. First, treatment accuracy is evaluated throughout the whole treated volume, yielding comprehensive verification. Second, the clinical significance of any deviations can be assessed through the generation of DVH curves and dose overlays on the

  14. 48 CFR 3052.223-90 - Accident and fire reporting (USCG).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 7 2014-10-01 2014-10-01 false Accident and fire... PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 3052.223-90 Accident and fire reporting (USCG). As prescribed in USCG guidance at (HSAR) 48 CFR 3023.9000(a), insert the following clause: Accident...

  15. 48 CFR 3052.223-90 - Accident and fire reporting (USCG).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Accident and fire... PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 3052.223-90 Accident and fire reporting (USCG). As prescribed in USCG guidance at (HSAR) 48 CFR 3023.9000(a), insert the following clause: Accident...

  16. 48 CFR 3052.223-90 - Accident and fire reporting (USCG).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 7 2012-10-01 2012-10-01 false Accident and fire... PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 3052.223-90 Accident and fire reporting (USCG). As prescribed in USCG guidance at (HSAR) 48 CFR 3023.9000(a), insert the following clause: Accident...

  17. 48 CFR 3052.223-90 - Accident and fire reporting (USCG).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CONTRACT CLAUSES Text of Provisions and Clauses 3052.223-90 Accident and fire reporting (USCG). As prescribed in USCG guidance at (HSAR) 48 CFR 3023.9000(a), insert the following clause: Accident and Fire... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Accident and fire reporting...

  18. Reference dosimeter system of the iaea

    NASA Astrophysics Data System (ADS)

    Mehta, Kishor; Girzikowsky, Reinhard

    1995-09-01

    Quality assurance programmes must be in operation at radiation processing facilities to satisfy national and international Standards. Since dosimetry has a vital function in these QA programmes, it is imperative that the dosimetry systems in use at these facilities are well calibrated with a traceability to a Primary Standard Dosimetry Laboratory. As a service to the Member States, the International Atomic Energy Agency operates the International Dose Assurance Service (IDAS) to assist in this process. The transfer standard dosimetry system that is used for this service is based on ESR spectrometry. The paper describes the activities undertaken at the IAEA Dosimetry Laboratory to establish the QA programme for its reference dosimetry system. There are four key elements of such a programme: quality assurance manual; calibration that is traceable to a Primary Standard Dosimetry Laboratory; a clear and detailed statement of uncertainty in the dose measurement; and, periodic quality audit.

  19. Can a commercial gel dosimetry system be used to verify stereotactic spinal radiotherapy treatment dose distributions?

    NASA Astrophysics Data System (ADS)

    Kairn, T.; Asena, A.; Crowe, S. B.; Livingstone, A.; Papworth, D.; Smith, S.; Sutherland, B.; Sylvander, S.; Franich, R. D.; Trapp, J. V.

    2017-05-01

    This study investigated the use of the TruView xylenol-orange-based gel and VISTA optical CT scanner (both by Modus Medical Inc, London, Canada), for use in verifying the accuracy of planned dose distributions for hypo-fractionated (stereotactic) vertebral treatments. Gel measurements were carried out using three stereotactic vertebral treatments and compared with planned doses calculated using the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, USA) as well as with film measurements made using Gafchromic EBT3 film (Ashland Inc, Covington, USA), to investigate the accuracy of the gel system. The gel was calibrated with reference to a moderate-dose gradient region in one of the gel samples. Generally, the gel measurements were able to approximate the close agreement between the doses calculated by the treatment planning system and the doses measured using film (which agreed with each other within 2%), despite lower resolution and bit depth. Poorer agreement was observed when the dose delivered to the gel exceeded the range of doses delivered in the calibration region. This commercial gel dosimetry system may be used to verify hypo-fractionated treatments of vertebral targets, although separate gel calibration measurements are recommended.

  20. Manned space programs accident/incident summaries (1963 - 1969)

    NASA Technical Reports Server (NTRS)

    1970-01-01

    This summary is a compilation of 508 mishaps assembled from company and NASA records which cover several years of manned space flight activity. The purpose is to provide information to be applied towards accident prevention. The accident/incident summaries are categorized by the following ten systems: cryogenic; electrical; facility/GSE; fuel and propellant; life support; ordnance; pressure; propulsion; structural; and transport/handling. Each accident/incident summary has been summarized by description, cause and recommended preventive action.

  1. In vitro exposure systems and dosimetry assessment tools for inhaled tobacco products: Workshop proceedings, conclusions and paths forward for in vitro model use.

    PubMed

    Behrsing, Holger; Hill, Erin; Raabe, Hans; Tice, Raymond; Fitzpatrick, Suzanne; Devlin, Robert; Pinkerton, Kent; Oberdörster, Günter; Wright, Chris; Wieczorek, Roman; Aufderheide, Michaela; Steiner, Sandro; Krebs, Tobias; Asgharian, Bahman; Corley, Richard; Oldham, Michael; Adamson, Jason; Li, Xiang; Rahman, Irfan; Grego, Sonia; Chu, Pei-Hsuan; McCullough, Shaun; Curren, Rodger

    2017-07-01

    In 2009, the passing of the Family Smoking Prevention and Tobacco Control Act facilitated the establishment of the FDA Center for Tobacco Products (CTP), and gave it regulatory authority over the marketing, manufacture and distribution of tobacco products, including those termed 'modified risk'. On 4-6 April 2016, the Institute for In Vitro Sciences, Inc. (IIVS) convened a workshop conference entitled, In Vitro Exposure Systems and Dosimetry Assessment Tools for Inhaled Tobacco Products, to bring together stakeholders representing regulatory agencies, academia and industry to address the research priorities articulated by the FDA CTP. Specific topics were covered to assess the status of current in vitro smoke and aerosol/vapour exposure systems, as well as the various approaches and challenges to quantifying the complex exposures in in vitro pulmonary models developed for evaluating adverse pulmonary events resulting from tobacco product exposures. The four core topics covered were: a) Tobacco Smoke and E-Cigarette Aerosols; b) Air-Liquid Interface-In Vitro Exposure Systems; c) Dosimetry Approaches for Particles and Vapours/In Vitro Dosimetry Determinations; and d) Exposure Microenvironment/Physiology of Cells. The 2.5-day workshop included presentations from 20 expert speakers, poster sessions, networking discussions, and breakout sessions which identified key findings and provided recommendations to advance these technologies. Here, we will report on the proceedings, recommendations, and outcome of the April 2016 technical workshop, including paths forward for developing and validating non-animal test methods for tobacco product smoke and next generation tobacco product aerosol/vapour exposures. With the recent FDA publication of the final deeming rule for the governance of tobacco products, there is an unprecedented necessity to evaluate a very large number of tobacco-based products and ingredients. The questionable relevance, high cost, and ethical

  2. Some recent multi-frequency electron paramagnetic resonance results on systems relevant for dosimetry and dating.

    PubMed

    Callens, F; Vanhaelewyn, G; Matthys, P

    2002-04-01

    Electron Paramagnetic Resonance (EPR) applications like e.g. EPR dosimetry and dating, are usually performed at X-band frequencies because of practical reasons (cost, sample size, etc.). However, it is increasingly recognized that the radiation-induced EPR signals are strongly composite, what might affect dose/age estimates. A few recent examples from both the dosimetry and dating field, illustrating the problems, will be presented. The involved spectra are mainly due to carbonate-derived radicals (CO2-, CO3(3-), etc.). Measurements at higher microwave frequencies are often recommended to improve the insight into the spectra and/or the practical signal quantification. Recent results at Q- and W-band frequencies will show that a multi-frequency approach indeed opens many interesting perspectives in this field but also that each frequency may have specific (dis)advantages depending on the EPR probe and application involved. The discussion will concern carbonate-containing apatite single crystals, shells, modern and fossil tooth enamel.

  3. SU-F-J-100: Standardized Biodistribution Template for Nuclear Medicine Dosimetry Collection and Reporting

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kesner, A; Poli, G; Beykan, S

    Purpose: As the field of Nuclear Medicine moves forward with efforts to integrate radiation dosimetry into clinical practice we can identify the challenge posed by the lack of standardized dose calculation methods and protocols. All personalized internal dosimetry is derived by projecting biodistribution measurements into dosimetry calculations. In an effort to standardize organization of data and its reporting, we have developed, as a sequel to the EANM recommendation of “Good Dosimetry Reporting”, a freely available biodistribution template, which can be used to create a common point of reference for dosimetry data. It can be disseminated, interpreted, and used for methodmore » development widely across the field. Methods: A generalized biodistribution template was built in a comma delineated format (.csv) to be completed by users performing biodistribution measurements. The template is available for free download. The download site includes instructions and other usage details on the template. Results: This is a new resource developed for the community. It is our hope that users will consider integrating it into their dosimetry operations. Having biodistribution data available and easily accessible for all patients processed is a strategy for organizing large amounts of information. It may enable users to create their own databases that can be analyzed for multiple aspects of dosimetry operations. Furthermore, it enables population data to easily be reprocessed using different dosimetry methodologies. With respect to dosimetry-related research and publications, the biodistribution template can be included as supplementary material, and will allow others in the community to better compare calculations and results achieved. Conclusion: As dosimetry in nuclear medicine become more routinely applied in clinical applications, we, as a field, need to develop the infrastructure for handling large amounts of data. Our organ level biodistribution template can be

  4. Electromagnetic system for detection and localization of the miners caught by accident in mine

    NASA Astrophysics Data System (ADS)

    Pronenko, Vira; Dudkin, Fedir

    2016-04-01

    It is well known that the profession of a miner is one of the most dangerous in the world. Among the main causes of the people death in the underground coal mining enterprises is their untimely alerting of the accident, as well as the lack of information for the rescuers about the actual location of the miners after the accident. As world practice shows, the electromagnetic (EM) systems for the search and detection of people across a massive layer of rock are the most effective. Such systems are under development almost half a century in many countries dealing with mine industry. However, substantial progress related to the localization of personnel at a distance at least of 20-30 meters through the rock is not reached. In an emergency situation (failure or destruction of underground infrastructure), personnel search behind and beneath of obstruction should be provided urgently. But none of the standard technologies (RFID, DECT, WiFi, emitting cable), which use the stationary technical devices in mines, do not provide notification of people caught by accident location. The only technology that provides guaranteed delivery of messages about the accident to the mine personnel, regardless of their location and under any destruction in the mine, is low-frequency radio technology able to operate through the thickness of rocks. From the general theoretical considerations, it is clear that the miners localization system requires solving the inverse problem of the magnetic field source coordinates determining using the data of 3-component magnetic field measurements. A fundamentally new approach, based on the measurement of the magnetic field of the miner's responder beacon by two fixed and spaced three-component magnetic field receivers and solution of the inverse problem using the results of the magnetic field measurement, was proposed. As a result, the concept of the equipment for miners beacon search and localization implementation (MILES - miner's location emergency

  5. MO-DE-BRA-04: Hands-On Fluoroscopy Safety Training with Real-Time Patient and Staff Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vanderhoek, M; Bevins, N

    Purpose: Fluoroscopically guided interventions (FGI) are routinely performed across many different hospital departments. However, many involved staff members have minimal training regarding safe and optimal use of fluoroscopy systems. We developed and taught a hands-on fluoroscopy safety class incorporating real-time patient and staff dosimetry in order to promote safer and more optimal use of fluoroscopy during FGI. Methods: The hands-on fluoroscopy safety class is taught in an FGI suite, unique to each department. A patient equivalent phantom is set on the patient table with an ion chamber positioned at the x-ray beam entrance to the phantom. This provides a surrogatemore » measure of patient entrance dose. Multiple solid state dosimeters (RaySafe i2 dosimetry systemTM) are deployed at different distances from the phantom (0.1, 1, 3 meters), which provide surrogate measures of staff dose. Instructors direct participating clinical staff to operate the fluoroscopy system as they view live fluoroscopic images, patient entrance dose, and staff doses in real-time. During class, instructors work with clinical staff to investigate how patient entrance dose, staff doses, and image quality are affected by different parameters, including pulse rate, magnification, collimation, beam angulation, imaging mode, system geometry, distance, and shielding. Results: Real-time dose visualization enables clinical staff to directly see and learn how to optimize their use of their own fluoroscopy system to minimize patient and staff dose, yet maintain sufficient image quality for FGI. As a direct result of the class, multiple hospital departments have implemented changes to their imaging protocols, including reduction of the default fluoroscopy pulse rate and increased use of collimation and lower dose fluoroscopy modes. Conclusion: Hands-on fluoroscopy safety training substantially benefits from real-time patient and staff dosimetry incorporated into the class. Real-time dose

  6. A Human Factors Analysis and Classification System (HFACS) Examination of Commercial Vessel Accidents

    DTIC Science & Technology

    2012-09-01

    Naval Operations before the Congress on FY2013 Department of Navy posture. Heinrich , H . W. (1941). Industrial accident prevention : A scientific...Theory The core of the Domino Theory, developed by Herbert W. Heinrich who studied industrial safety in the early 1900s, is that accidents are a result...chain of events resulting in an accident . Heinrich likened the dominos to unsafe conditions or unsafe acts, where their subsequent removal prevents a

  7. Implicit dosimetry of microorganism photodynamic inactivation

    NASA Astrophysics Data System (ADS)

    Tamošiūnas, Mindaugas; Kuliešienė, Neringa; Daugelavičius, Rimantas

    2017-12-01

    Photosensitization based antibacterial treatment is efficient against a broad range of pathogens but it utilizes suboptimal dosimetry with an explicit (and very broad range) determination of sensitizer concentration, light dose and fluence rates. In this study we verified the implicit dosimetry approach for pathogen photodynamic treatment, employing protoporphyrin IX (ppIX) photobleaching to assess the killing efficacy against Staphylococcus aureus and Candida albicans cells. The results show that there was an increased kill of S. aureus and C. albicans at higher degree of ppIX fluorescence decay. Therefore ppIX photobleaching can be incorporated into the PDI dose metric offering to predict the pathogen killing efficacy during photodynamic treatment.

  8. High resolution MR based polymer dosimetry versus film densitometry: a systematic study based on the modulation transfer function approach.

    PubMed

    Berg, A; Pernkopf, M; Waldhäusl, C; Schmidt, W; Moser, E

    2004-09-07

    Precise methods of modem radiation therapy such as intensity modulated radiotherapy (IMRT), brachytherapy (BT) and high LET irradiation allow for high dose localization in volumes of a few mm3. However, most dosimetry methods-ionization chambers, TLD arrangements or silicon detectors, for example-are not capable of detecting sub-mm dose variations or do not allow for simple dose imaging. Magnetic resonance based polymer dosimetry (MRPD) appears to be well suited to three-dimensional high resolution relative dosimetry but the spatial resolution based on a systematic modulation transfer function (MTF) approach has not yet been investigated. We offer a theoretical construct for addressing the spatial resolution in different dose imaging systems, i.e. the dose modulation transfer function (DMTF) approach, an experimental realization of this concept with a phantom and quantitative comparisons between two dosimetric systems: polymer gel and film dosimetry. Polymer gel samples were irradiated by Co-60 photons through an absorber grid which is characterized by periodic structures of different spatial period (a), the smallest one at width of a/2 = 280 microm. The modulation in dose under the grid is visualized via calibrated, high resolution, parameter-selective (T2) and dose images based on multi-echo MR imaging. The DMTF is obtained from the modulation depth of the spin-spin relaxation time (T2) after calibration. Voxel sizes below 0.04 mm3 could be achieved, which are significantly smaller than those reported in MR based dose imaging on polymer gels elsewhere, using a powerful gradient system and a highly sensitive small birdcage resonator on a whole-body 3T MR scanner. Dose modulations at 22% of maximum dose amplitude could be observed at about 2 line pairs per mm. The polymer DMTF results are compared to those of a typical clinical film-scanner system. This study demonstrates that MR based gel dosimetry at 200 microm pixel resolution might even be superior, with

  9. Toward a real-time in vivo dosimetry system using plastic scintillation detectors

    PubMed Central

    Archambault, Louis; Briere, Tina M.; Pönisch, Falk; Beaulieu, Luc; Kuban, Deborah A.; Lee, Andrew; Beddar, Sam

    2010-01-01

    Purpose In this work, we present and validate a plastic scintillation detector (PSD) system designed for real-time multi-probe in vivo measurements. Methods and Materials The PSDs were built with a dose-sensitive volume of 0.4 mm3. PSDs were assembled into modular detector patches, each containing 5 closely packed PSDs. Continuous dose readings were performed every 150 ms, with a gap between consecutive readings of less than 0.3 ms. We first studied the effect of electron multiplication. We then assessed system performance in acrylic and anthropomorphic pelvic phantoms. Results The PSDs are compatible with clinical rectal balloons and are easily inserted into the anthropomorphic phantom. With an electron multiplication average gain factor of 40, a twofold increase in the signal-to-noise ratio was observed, making near real-time dosimetry feasible. Under calibration conditions, the PSDs agreed with ion chamber measurements to 0.08%. Precision, evaluated as a function of the total dose delivered, ranged from 2.3% at 2 cGy to 0.4% at 200 cGy. Conclusion Real-time PSD measurements are highly accurate and precise. These PSDs can be mounted onto rectal balloons, transforming these clinical devices into in vivo dose detectors without modifying current clinical practice. Real-time monitoring of the dose delivered near the rectum during prostate radiation therapy should help radiation oncologists protect this sensitive normal structure. PMID:20231074

  10. 33 CFR 174.121 - Forwarding of casualty or accident reports.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... accident reports. 174.121 Section 174.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... § 174.121 Forwarding of casualty or accident reports. Within 30 days of the receipt of a casualty or accident report, each State that has an approved numbering system must forward a copy of that report to the...

  11. 33 CFR 174.121 - Forwarding of casualty or accident reports.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... accident reports. 174.121 Section 174.121 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... § 174.121 Forwarding of casualty or accident reports. Within 30 days of the receipt of a casualty or accident report, each State that has an approved numbering system must forward a copy of that report to the...

  12. Aviation Safety Program: Weather Accident Prevention (WxAP) Development of WxAP System Architecture And Concepts of Operation

    NASA Technical Reports Server (NTRS)

    Grantier, David

    2003-01-01

    This paper presents viewgraphs on the development of the Weather Accident Prevention (WxAP) System architecture and Concept of Operation (CONOPS) activities. The topics include: 1) Background Information on System Architecture/CONOPS Activity; 2) Activity Work in Progress; and 3) Anticipated By-Products.

  13. Review on the characteristics of radiation detectors for dosimetry and imaging

    NASA Astrophysics Data System (ADS)

    Seco, Joao; Clasie, Ben; Partridge, Mike

    2014-10-01

    The enormous advances in the understanding of human anatomy, physiology and pathology in recent decades have led to ever-improving methods of disease prevention, diagnosis and treatment. Many of these achievements have been enabled, at least in part, by advances in ionizing radiation detectors. Radiology has been transformed by the implementation of multi-slice CT and digital x-ray imaging systems, with silver halide films now largely obsolete for many applications. Nuclear medicine has benefited from more sensitive, faster and higher-resolution detectors delivering ever-higher SPECT and PET image quality. PET/MR systems have been enabled by the development of gamma ray detectors that can operate in high magnetic fields. These huge advances in imaging have enabled equally impressive steps forward in radiotherapy delivery accuracy, with 4DCT, PET and MRI routinely used in treatment planning and online image guidance provided by cone-beam CT. The challenge of ensuring safe, accurate and precise delivery of highly complex radiation fields has also both driven and benefited from advances in radiation detectors. Detector systems have been developed for the measurement of electron, intensity-modulated and modulated arc x-ray, proton and ion beams, and around brachytherapy sources based on a very wide range of technologies. The types of measurement performed are equally wide, encompassing commissioning and quality assurance, reference dosimetry, in vivo dosimetry and personal and environmental monitoring. In this article, we briefly introduce the general physical characteristics and properties that are commonly used to describe the behaviour and performance of both discrete and imaging detectors. The physical principles of operation of calorimeters; ionization and charge detectors; semiconductor, luminescent, scintillating and chemical detectors; and radiochromic and radiographic films are then reviewed and their principle applications discussed. Finally, a general

  14. A methodology for dosimetry audit of rotational radiotherapy using a commercial detector array.

    PubMed

    Hussein, Mohammad; Tsang, Yatman; Thomas, Russell A S; Gouldstone, Clare; Maughan, David; Snaith, Julia A D; Bolton, Steven C; Nisbet, Andrew; Clark, Catharine H

    2013-07-01

    To develop a methodology for the use of a commercial detector array in dosimetry audits of rotational radiotherapy. The methodology was developed as part of the development of a national audit of rotational radiotherapy. Ten cancer centres were asked to create a rotational radiotherapy treatment plan for a three-dimensional treatment-planning-system (3DTPS) test and audited. Phantom measurements using a commercial 2D ionisation chamber (IC) array were compared with measurements using 0.125 cm(3) IC, Gafchromic film and alanine pellets in the same plane. Relative and absolute gamma index (γ) comparisons were made for Gafchromic film and 2D-Array planes, respectively. Comparisons between individual detectors within the 2D-Array against the corresponding IC and alanine measurement showed a statistically significant concordance correlation coefficient (both ρc>0.998, p<0.001) with mean difference of -1.1 ± 1.1% and -0.8 ± 1.1%, respectively, in a high dose PTV. In the γ comparison between the 2D-Array and film it was that the 2D-Array was more likely to fail planes where there was a dose discrepancy due to the absolute analysis performed. It has been found that using a commercial detector array for a dosimetry audit of rotational radiotherapy is suitable in place of standard systems of dosimetry. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Rail-highway crossing accident prediction research results - FY80

    DOT National Transportation Integrated Search

    1981-01-01

    This report presents the results of research performed at the : Transportation Systems Center (TSC) dealing with mathematical : methods of predicting accidents at rail-highway crossings. The : work consists of three parts : Part I - Revised DOT Accid...

  16. Electromagnetic system for detection and localization of miners caught in mine accidents

    NASA Astrophysics Data System (ADS)

    Pronenko, Vira; Dudkin, Fedir

    2016-12-01

    The profession of a miner is one of the most dangerous in the world. Among the main causes of fatalities in underground coal mines are the delayed alert of the accident and the lack of information regarding the actual location of the miners after the accident. In an emergency situation (failure or destruction of underground infrastructure), personnel search behind and beneath blockage needs to be performed urgently. However, none of the standard technologies - radio-frequency identification (RFID), Digital Enhanced Cordless Telecommunications (DECT), Wi-Fi, emitting cables, which use the stationary technical devices in mines - provide information about the miners location with the necessary precision. The only technology that is able to provide guaranteed delivery of messages to mine personnel, regardless of their location and under any destruction in the mine, is low-frequency radio technology, which is able to operate through the thickness of rocks even if they are wet. The proposed new system for miner localization is based on solving the inverse problem of determining the magnetic field source coordinates using the data of magnetic field measurements. This approach is based on the measurement of the magnetic field radiated by the miner's responder beacon using two fixed and spaced three-component magnetic field receivers and the inverse problem solution. As a result, a working model of the system for miner's beacon search and localization (MILES - MIner's Location Emergency System) was developed and successfully tested. This paper presents the most important aspects of this development and the results of experimental tests.

  17. SU-E-T-117: Analysis of the ArcCHECK Dosimetry Gamma Failure Using the 3DVH System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cho, S; Choi, W; Lee, H

    2015-06-15

    Purpose: To evaluate gamma analysis failure for the VMAT patient specific QA using ArcCHECK cylindrical phantom. The 3DVH system(Sun Nuclear, FL) was used to analyze the dose difference statistic between measured dose and treatment planning system calculated dose. Methods: Four case of gamma analysis failure were selected retrospectively. Our institution gamma analysis indexes were absolute dose, 3%/3mm and 90%pass rate in the ArcCHECK dosimetry. The collapsed cone convolution superposition (CCCS) dose calculation algorithm for VMAT was used. Dose delivery was performed with Elekta Agility. The A1SL(standard imaging, WI) and cavity plug were used for point dose measurement. Delivery QA plansmore » and images were used for 3DVH Reference data instead of patient plan and image. The measured data of ‘.txt’ file was used for comparison at diodes to acquire a global dose level. The,.acml’ file was used for AC-PDP and to calculated point dose. Results: The global dose of 3DVH was calculated as 1.10 Gy, 1.13, 1.01 and 0.2 Gy respectively. The global dose of 0.2 Gy case was induced by distance discrepancy. The TPS calculated point dose of was 2.33 Gy to 2.77 Gy and 3DVH calculated dose was 2.33 Gy to 2.68 Gy. The maximum dose differences were −2.83% and −3.1% for TPS vs. measured dose and TPS vs. 3DVH calculated respectively in the same case. The difference between measured and 3DVH was 0.1% in that case. The 3DVH gamma pass rate was 98% to 99.7%. Conclusion: We found the TPS calculation error by 3DVH calculation using ArcCHECK measured dose. It seemed that our CCCS algorithm RTP system over estimated at the central region and underestimated scattering at the peripheral diode detector point. The relative gamma analysis and point dose measurement would be recommended for VMAT DQA in the gamma failure case of ArcCHECK dosimetry.« less

  18. Technical basis for external dosimetry at the Waste Isolation Pilot Plant (WIPP)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bradley, E.W.; Wu, C.F.; Goff, T.E.

    1993-12-31

    The WIPP External Dosimetry Program, administered by Westinghouse Electric Corporation, Waste Isolation Division, for the US Department of Energy (DOE), provides external dosimetry support services for operations at the Waste Isolation Pilot Plant (WIPP) Site. These operations include the receipt, experimentation with, storage, and disposal of transuranic (TRU) wastes. This document describes the technical basis for the WIPP External Radiation Dosimetry Program. The purposes of this document are to: (1) provide assurance that the WIPP External Radiation Dosimetry Program is in compliance with all regulatory requirements, (2) provide assurance that the WIPP External Radiation Dosimetry Program is derived from amore » sound technical base, (3) serve as a technical reference for radiation protection personnel, and (4) aid in identifying and planning for future needs. The external radiation exposure fields are those that are documented in the WIPP Final Safety Analysis Report.« less

  19. Advanced radiochromic film methodologies for quantitative dosimetry of small and nonstandard fields

    NASA Astrophysics Data System (ADS)

    Rosen, Benjamin S.

    Radiotherapy treatments with small and nonstandard fields are increasing in use as collimation and targeting become more advanced, which spare normal tissues while increasing tumor dose. However, dosimetry of small and nonstandard fields is more difficult than that of conventional fields due to loss of lateral charged-particle equilibrium, tight measurement setup requirements, source occlusion, and the volume-averaging effect of conventional dosimeters. This work aims to create new small and nonstandard field dosimetry protocols using radiochromic film (RCF) in conjunction with novel readout and analysis methodologies. It also is the intent of this work to develop an improved understanding of RCF structure and mechanics for its quantitative use in general applications. Conventional digitization techniques employ white-light, flatbed document scanners or scanning-laser densitometers which are not optimized for RCF dosimetry. A point-by-point precision laser densitometry system (LDS) was developed for this work to overcome the film-scanning artifacts associated with the use of conventional digitizers, such as positional scan dependence, off-axis light scatter, glass bed interference, and low signal-to-noise ratios. The LDS was shown to be optically traceable to national standards and to provide highly reproducible density measurements. Use of the LDS resulted in increased agreement between RCF dose measurements and the single-hit detector model of film response, facilitating traceable RCF calibrations based on calibrated physical quantities. GafchromicRTM EBT3 energy response to a variety of reference x-ray and gamma-ray beam qualities was also investigated. Conventional Monte Carlo methods are not capable of predicting film intrinsic energy response to arbitrary particle spectra. Therefore, a microdosimetric model was developed to simulate the underlying physics of the radiochromic mechanism and was shown to correctly predict the intrinsic response relative to a

  20. Study of EPR/ESR Dosimetry in Fingernails as a Method for Assessing Dose of Victims of Radiological Accidents/Incidents

    DTIC Science & Technology

    2008-06-17

    dosimeters . .............................................................................................. 117 Figure 4-2. Flow chart illustrating...alanine, various sugars, quartz in rocks and sulfates, as EPR dosimeters [15]. Alternatively, radiation-induced EPR signals have been detected using...the medical response to radiological accidents, as a method for estimating radiation dose without the use of physical dosimeters and using exposed

  1. Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in (60)Co beams.

    PubMed

    Mrčela, I; Bokulić, T; Izewska, J; Budanec, M; Fröbe, A; Kusić, Z

    2011-09-21

    A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for in vivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in (60)Co beams. The reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in vivo dosimetry systems.

  2. Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in 60Co beams

    NASA Astrophysics Data System (ADS)

    Mrčela, I.; Bokulić, T.; Izewska, J.; Budanec, M.; Fröbe, A.; Kusić, Z.

    2011-09-01

    A commercial optically stimulated luminescence (OSL) dosimetry system was investigated for in vivo dosimetry in radiation therapy. Dosimetric characteristics of InLight dot dosimeters and a microStar reader (Landauer Inc.) were tested in 60Co beams. The reading uncertainty of a single dosimeter was 0.6%. The reproducibility of a set of dosimeters after a single irradiation was 1.6%, while in repeated irradiations of the same dosimeters it was found to be 3.5%. When OSL dosimeters were optically bleached between exposures, the reproducibility of repeated measurements improved to 1.0%. Dosimeters were calibrated for the entrance dose measurements and a full set of correction factors was determined. A pilot patient study that followed phantom validation testing included more than 100 measured fields with a mean relative difference of the measured entrance dose from the expected dose of 0.8% and the standard deviation of 2.5%. In conclusion, these results demonstrate that OSL dot dosimeters represent a valid alternative to already established in vivo dosimetry systems.

  3. [Chernobyl nuclear power plant accident and Tokaimura criticality accident].

    PubMed

    Takada, Jun

    2012-03-01

    It is clear from inspection of historical incidents that the scale of disasters in a nuclear power plant accident is quite low level overwhelmingly compared with a nuclear explosion in nuclear war. Two cities of Hiroshima and Nagasaki were destroyed by nuclear blast with about 20 kt TNT equivalent and then approximately 100,000 people have died respectively. On the other hand, the number of acute death is 30 in the Chernobyl nuclear reactor accident. In this chapter, we review health hazards and doses in two historical nuclear incidents of Chernobyl and Tokaimura criticality accident and then understand the feature of the radiation accident in peaceful utilization of nuclear power.

  4. Preliminary calculations related to the accident at Three Mile Island

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kirchner, W.L.; Stevenson, M.G.

    This report discusses preliminary studies of the Three Mile Island Unit 2 (TMI-2) accident based on available methods and data. The work reported includes: (1) a TRAC base case calculation out to 3 hours into the accident sequence; (2) TRAC parametric calculations, these are the same as the base case except for a single hypothetical change in the system conditions, such as assuming the high pressure injection (HPI) system operated as designed rather than as in the accident; (3) fuel rod cladding failure, cladding oxidation due to zirconium metal-steam reactions, hydrogen release due to cladding oxidation, cladding ballooning, cladding embrittlement,more » and subsequent cladding breakup estimates based on TRAC calculated cladding temperatures and system pressures. Some conclusions of this work are: the TRAC base case accident calculation agrees very well with known system conditions to nearly 3 hours into the accident; the parametric calculations indicate that, loss-of-core cooling was most influenced by the throttling of High-Pressure Injection (HPI) flows, given the accident initiating events and the pressurizer electromagnetic-operated valve (EMOV) failing to close as designed; failure of nearly all the rods and gaseous fission product gas release from the failed rods is predicted to have occurred at about 2 hours and 30 minutes; cladding oxidation (zirconium-steam reaction) up to 3 hours resulted in the production of approximately 40 kilograms of hydrogen.« less

  5. Modelling and Dosimetry for Alpha-Particle Therapy

    PubMed Central

    Sgouros, George; Hobbs, Robert F.; Song, Hong

    2015-01-01

    As a consequence of the high potency and short range of alpha-particles, radiopharmaceutical therapy with alpha-particle emitting radionuclides is a promising treatment approach that is under active pre-clinical and clinical investigation. To understand and predict the biological effects of alpha-particle radiopharmaceuticals, dosimetry is required at the micro or multi-cellular scale level. At such a scale, highly non-uniform irradiation of the target volume may be expected and the utility of a single absorbed dose value to predict biological effects comes into question. It is not currently possible to measure the pharmacokinetic input required for micro scale dosimetry in humans. Accordingly, pre-clinical studies are required to provide the pharmacokinetic data for dosimetry calculations. The translation of animal data to the human requires a pharmacokinetic model that links macro- and micro-scale pharmacokinetics thereby enabling the extrapolation of micro-scale kinetics from macroscopic measurements. These considerations along with a discussion of the appropriate physical quantity and related units for alpha-particle radiopharmaceutical therapy are examined in this review. PMID:22201712

  6. Hanford Internal Dosimetry Project manual. Revision 1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carbaugh, E.H.; Bihl, D.E.; MacLellan, J.A.

    1994-07-01

    This document describes the Hanford Internal Dosimetry Project, as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy and its Hanford contractors. Project services include administrating the bioassay monitoring program, evaluating and documenting assessment of potential intakes and internal dose, ensuring that analytical laboratories conform to requirements, selecting and applying appropriate models and procedures for evaluating radionuclide deposition and the resulting dose, and technically guiding and supporting Hanford contractors in matters regarding internal dosimetry. Specific chapters deal with the following subjects: practices of the project, including interpretation of applicable DOE Orders, regulations, andmore » guidance into criteria for assessment, documentation, and reporting of doses; assessment of internal dose, including summary explanations of when and how assessments are performed; recording and reporting practices for internal dose; selection of workers for bioassay monitoring and establishment of type and frequency of bioassay measurements; capability and scheduling of bioassay monitoring services; recommended dosimetry response to potential internal exposure incidents; quality control and quality assurance provisions of the program.« less

  7. Progress in high-dose radiation dosimetry. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.

    1981-01-01

    The last decade has witnessed a deluge of new high-dose dosimetry techniques and expended applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Requirements for a stable and reliable transfer dose meters have led to further developments of several important high-dose systems: thermoluminescent materials, radiochromic dyes, ceric-cerous solutions analyzed by high-frequency oscillometry. A number of other prospective dosimeters are also treated in this review. In addition, an IAEA program of high-dose intercomparison and standardization for industrial radiation processing is described.

  8. Progress in high-dose radiation dosimetry. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.

    1981-01-01

    The last decade has witnessed a deluge of new high-dose dosimetry techniques and expended applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Requirements for a stable and reliable transfer dose meters have led to further developments of several important high-dose systems: thermoluminescent materials, radiochromic dyes, ceric-cerous solutions analyzed by high-frequency oscillometry. A number of other prospective dosimeters also treated in this review. In addition, an IAEA programme of high-dose intercomparison and standardization for industrial radiation processing is described.

  9. Underreporting of maritime accidents to vessel accident databases.

    PubMed

    Hassel, Martin; Asbjørnslett, Bjørn Egil; Hole, Lars Petter

    2011-11-01

    Underreporting of maritime accidents is a problem not only for authorities trying to improve maritime safety through legislation, but also to risk management companies and other entities using maritime casualty statistics in risk and accident analysis. This study collected and compared casualty data from 01.01.2005 to 31.12.2009, from IHS Fairplay and the maritime authorities from a set of nations. The data was compared to find common records, and estimation of the true number of occurred accidents was performed using conditional probability given positive dependency between data sources, several variations of the capture-recapture method, calculation of best case scenario assuming perfect reporting, and scaling up a subset of casualty information from a marine insurance statistics database. The estimated upper limit reporting performance for the selected flag states ranged from 14% to 74%, while the corresponding estimated coverage of IHS Fairplay ranges from 4% to 62%. On average the study results document that the number of unreported accidents makes up roughly 50% of all occurred accidents. Even in a best case scenario, only a few flag states come close to perfect reporting (94%). The considerable scope of underreporting uncovered in the study, indicates that users of statistical vessel accident data should assume a certain degree of underreporting, and adjust their analyses accordingly. Whether to use correction factors, a safety margin, or rely on expert judgment, should be decided on a case by case basis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. World commercial aircraft accidents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accidentmore » is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.« less

  11. Development of the simulation system {open_quotes}IMPACT{close_quotes} for analysis of nuclear power plant severe accidents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Naitoh, Masanori; Ujita, Hiroshi; Nagumo, Hiroichi

    1997-07-01

    The Nuclear Power Engineering Corporation (NUPEC) has initiated a long-term program to develop the simulation system {open_quotes}IMPACT{close_quotes} for analysis of hypothetical severe accidents in nuclear power plants. IMPACT employs advanced methods of physical modeling and numerical computation, and can simulate a wide spectrum of senarios ranging from normal operation to hypothetical, beyond-design-basis-accident events. Designed as a large-scale system of interconnected, hierarchical modules, IMPACT`s distinguishing features include mechanistic models based on first principles and high speed simulation on parallel processing computers. The present plan is a ten-year program starting from 1993, consisting of the initial one-year of preparatory work followed bymore » three technical phases: Phase-1 for development of a prototype system; Phase-2 for completion of the simulation system, incorporating new achievements from basic studies; and Phase-3 for refinement through extensive verification and validation against test results and available real plant data.« less

  12. Dosimetry for audit and clinical trials: challenges and requirements

    NASA Astrophysics Data System (ADS)

    Kron, T.; Haworth, A.; Williams, I.

    2013-06-01

    Many important dosimetry audit networks for radiotherapy have their roots in clinical trial quality assurance (QA). In both scenarios it is essential to test two issues: does the treatment plan conform with the clinical requirements and is the plan a reasonable representation of what is actually delivered to a patient throughout their course of treatment. Part of a sound quality program would be an external audit of these issues with verification of the equivalence of plan and treatment typically referred to as a dosimetry audit. The increasing complexity of radiotherapy planning and delivery makes audits challenging. While verification of absolute dose delivered at a reference point was the standard of external dosimetry audits two decades ago this is often deemed inadequate for verification of treatment approaches such as Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT). As such, most dosimetry audit networks have successfully introduced more complex tests of dose delivery using anthropomorphic phantoms that can be imaged, planned and treated as a patient would. The new challenge is to adapt this approach to ever more diversified radiotherapy procedures with image guided/adaptive radiotherapy, motion management and brachytherapy being the focus of current research.

  13. A survey of current in vivo radiotherapy dosimetry practice.

    PubMed

    Edwards, C R; Grieveson, M H; Mountford, P J; Rolfe, P

    1997-03-01

    A questionnaire was sent out to 57 radiotherapy physics departments in the United Kingdom to determine the type of dosemeters used for in vivo measurements inside and outside X-ray treatment fields, and whether any correction is made for energy dependence when the dose to critical organs outside the main beam is estimated. 44 responses were received. 11 centres used a semi-conductor for central axis dosimetry compared with only two centres which used thermoluminescent dosimetry (TLD). 37 centres carried out dosimetry measurements outside the main beam; 25 centres used TLD and 12 centres used a semi-conductor detector. Of the 16 centres measuring the dose at both sites. 11 used a semi-conductor for the central axis measurement, but only four of those 11 changed to TLD for critical organ dosimetry despite the latter's lower variation in energy response. None of the centres stated that they made a correction for the variation in detector energy response when making measurements outside the main beam, indicating a need for a more detailed evaluation of the energy response of these detectors and the energy spectra outside the main beam.

  14. Macroscopic to Microscopic Scales of Particulate Dosimetry: From Source to Fate in the Body

    EPA Science Inventory

    Additional perspective with regards to particle dosimetry is achieved by exploring dosimetry across a range of scales from macroscopic to microscopic in scope. Typically, one thinks of dosimetry as what happens when a particle is inhaled, where it is deposited, and how it is clea...

  15. Magnetic Fluid Hyperthermia for Bladder Cancer: A Preclinical Dosimetry Study

    PubMed Central

    Oliveira, Tiago R.; Stauffer, Paul R.; Lee, Chen-Ting; Landon, Chelsea D.; Etienne, Wiguins; Ashcraft, Kathleen A.; McNerny, Katie L.; Mashal, Alireza; Nouls, John; Maccarini, Paolo F.; Beyer, Wayne F.; Inman, Brant; Dewhirst, Mark W.

    2014-01-01

    Purpose This paper describes a preclinical investigation of the feasibility of thermotherapy treatment of bladder cancer with Magnetic Fluid Hyperthermia (MFH), performed by analyzing the thermal dosimetry of nanoparticle heating in a rat bladder model. Materials and Methods The bladders of twenty-five female rats were instilled with magnetite-based nanoparticles, and hyperthermia was induced using a novel small animal magnetic field applicator (Actium Biosystems, Boulder, CO). We aimed to increase the bladder lumen temperature to 42°C in <10 min and maintain that temperature for 60 min. Temperatures were measured within the bladder lumen and throughout the rat with seven fiberoptic probes (OpSens Technologies, Quebec, Canada). An MRI analysis was used to confirm the effectiveness of the catheterization method to deliver and maintain various nanoparticle volumes within the bladder. Thermal dosimetry measurements recorded the temperature rise of rat tissues for a variety of nanoparticle exposure conditions. Results Thermal dosimetry data demonstrated our ability to raise and control the temperature of rat bladder lumen ≥1°C/min to a steady-state of 42°C with minimal heating of surrounding normal tissues. MRI scans confirmed the homogenous nanoparticle distribution throughout the bladder. Conclusion These data demonstrate that our MFH system with magnetite-based nanoparticles provide well-localized heating of rat bladder lumen with effective control of temperature in the bladder and minimal heating of surrounding tissues. PMID:24050253

  16. Less than severe worst case accidents

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sanders, G.A.

    1996-08-01

    Many systems can provide tremendous benefit if operating correctly, produce only an inconvenience if they fail to operate, but have extreme consequences if they are only partially disabled such that they operate erratically or prematurely. In order to assure safety, systems are often tested against the most severe environments and accidents that are considered possible to ensure either safe operation or safe failure. However, it is often the less severe environments which result in the ``worst case accident`` since these are the conditions in which part of the system may be exposed or rendered unpredictable prior to total system failure.more » Some examples of less severe mechanical, thermal, and electrical environments which may actually be worst case are described as cautions for others in industries with high consequence operations or products.« less

  17. An Application of CICCT Accident Categories to Aviation Accidents in 1988-2004

    NASA Technical Reports Server (NTRS)

    Evans, Joni K.

    2007-01-01

    Interventions or technologies developed to improve aviation safety often focus on specific causes or accident categories. Evaluation of the potential effectiveness of those interventions is dependent upon mapping the historical aviation accidents into those same accident categories. To that end, the United States civil aviation accidents occurring between 1988 and 2004 (n=26,117) were assigned accident categories based upon the taxonomy developed by the CAST/ICAO Common Taxonomy Team (CICTT). Results are presented separately for four main categories of flight rules: Part 121 (large commercial air carriers), Scheduled Part 135 (commuter airlines), Non-Scheduled Part 135 (on-demand air taxi) and Part 91 (general aviation). Injuries and aircraft damage are summarized by year and by accident category.

  18. 33 CFR 174.107 - Contents of casualty or accident report form.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Contents of casualty or accident... System Requirements § 174.107 Contents of casualty or accident report form. Each form for reporting a vessel casualty or accident must contain the information required in § 173.57 of this chapter. ...

  19. 33 CFR 174.107 - Contents of casualty or accident report form.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Contents of casualty or accident... System Requirements § 174.107 Contents of casualty or accident report form. Each form for reporting a vessel casualty or accident must contain the information required in § 173.57 of this chapter. ...

  20. Applicability of Topaz Composites to Electron Dosimetry

    NASA Astrophysics Data System (ADS)

    Bomfim, K. S.; Souza, D. N.

    2010-11-01

    Thermoluminescent dosimetric topaz properties have been investigated and the results have shown that this mineral presents characteristics of a good dosimeter mainly in doses evaluation in radiotherapy with photons beams in radiotherapy. Typical applications of thermoluminescent dosimeters in radiotherapy are: in vivo dosimetry on patients (either as a routine quality assurance procedure or for dose monitoring in special cases); verification of treatment techniques; dosimetry audits; and comparisons among hospitals. The mean aim of this work was to evaluate the efficiency of topaz-Teflon pellets as thermoluminescent dosimeters in high-energy electron beams used to radiotherapy. Topaz-Teflon pellets were used as TLD.

  1. Implementation of an intraoperative electron radiotherapy in vivo dosimetry program.

    PubMed

    López-Tarjuelo, Juan; Morillo-Macías, Virginia; Bouché-Babiloni, Ana; Boldó-Roda, Enrique; Lozoya-Albacar, Rafael; Ferrer-Albiach, Carlos

    2016-03-15

    Intraoperative electron radiotherapy (IOERT) is a highly selective radiotherapy technique which aims to treat restricted anatomic volumes during oncological surgery and is now the subject of intense re-evaluation. In vivo dosimetry has been recommended for IOERT and has been identified as a risk-reduction intervention in the context of an IOERT risk analysis. Despite reports of fruitful experiences, information about in vivo dosimetry in intraoperative radiotherapy is somewhat scarce. Therefore, the aim of this paper is to report our experience in developing a program of in vivo dosimetry for IOERT, from both multidisciplinary and practical approaches, in a consistent patient series. We also report several current weaknesses. Reinforced TN-502RDM-H mobile metal oxide semiconductor field effect transistors (MOSFETs) and Gafchromic MD-55-2 films were used as a redundant in vivo treatment verification system with an Elekta Precise fixed linear accelerator for calibrations and treatments. In vivo dosimetry was performed in 45 patients in cases involving primary tumors or relapses. The most frequent primary tumors were breast (37 %) and colorectal (29 %), and local recurrences among relapses was 83 %. We made 50 attempts to measure with MOSFETs and 48 attempts to measure with films in the treatment zones. The surgical team placed both detectors with supervision from the radiation oncologist and following their instructions. The program was considered an overall success by the different professionals involved. The absorbed doses measured with MOSFETs and films were 93.8 ± 6.7 % and 97.9 ± 9.0 % (mean ± SD) respectively using a scale in which 90 % is the prescribed dose and 100 % is the maximum absorbed dose delivered by the beam. However, in 10 % of cases we experienced dosimetric problems due to detector misalignment, a situation which might be avoided with additional checks. The useful MOSFET lifetime length and the film sterilization procedure should also be

  2. PDT dose dosimetry for Photofrin-mediated pleural photodynamic therapy (pPDT)

    NASA Astrophysics Data System (ADS)

    Ong, Yi Hong; Kim, Michele M.; Finlay, Jarod C.; Dimofte, Andreea; Singhal, Sunil; Glatstein, Eli; Cengel, Keith A.; Zhu, Timothy C.

    2018-01-01

    Photosensitizer fluorescence excited by photodynamic therapy (PDT) treatment light can be used to monitor the in vivo concentration of the photosensitizer and its photobleaching. The temporal integral of the product of in vivo photosensitizer concentration and light fluence is called PDT dose, which is an important dosimetry quantity for PDT. However, the detected photosensitizer fluorescence may be distorted by variations in the absorption and scattering of both excitation and fluorescence light in tissue. Therefore, correction of the measured fluorescence for distortion due to variable optical properties is required for absolute quantification of photosensitizer concentration. In this study, we have developed a four-channel PDT dose dosimetry system to simultaneously acquire light dosimetry and photosensitizer fluorescence data. We measured PDT dose at four sites in the pleural cavity during pleural PDT. We have determined an empirical optical property correction function using Monte Carlo simulations of fluorescence for a range of physiologically relevant tissue optical properties. Parameters of the optical property correction function for Photofrin fluorescence were determined experimentally using tissue-simulating phantoms. In vivo measurements of photosensitizer fluorescence showed negligible photobleaching of Photofrin during the PDT treatment, but large intra- and inter-patient heterogeneities of in vivo Photofrin concentration are observed. PDT doses delivered to 22 sites in the pleural cavity of 8 patients were different by 2.9 times intra-patient and 8.3 times inter-patient.

  3. Hanford Internal Dosimetry Program Manual, PNL-MA-552

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2003-10-10

    This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP). It describes the roles of and relationships between the IDP and site contractors, and provides recommendations and guidance for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs. Guidance includes identifying conditions under which workers should be placed on bioassay programs, types, descritptions, and capabilities of measurements, suggested routine bioassay programs, limitations on services, and practices for recording and reporting results.

  4. A systems approach to accident causation in mining: an application of the HFACS method.

    PubMed

    Lenné, Michael G; Salmon, Paul M; Liu, Charles C; Trotter, Margaret

    2012-09-01

    This project aimed to provide a greater understanding of the systemic factors involved in mining accidents, and to examine those organisational and supervisory failures that are predictive of sub-standard performance at operator level. A sample of 263 significant mining incidents in Australia across 2007-2008 were analysed using the Human Factors Analysis and Classification System (HFACS). Two human factors specialists independently undertook the analysis. Incidents occurred more frequently in operations concerning the use of surface mobile equipment (38%) and working at heights (21%), however injury was more frequently associated with electrical operations and vehicles and machinery. Several HFACS categories appeared frequently: skill-based errors (64%) and violations (57%), issues with the physical environment (56%), and organisational processes (65%). Focussing on the overall system, several factors were found to predict the presence of failures in other parts of the system, including planned inappropriate operations and team resource management; inadequate supervision and team resource management; and organisational climate and inadequate supervision. It is recommended that these associations deserve greater attention in future attempts to develop accident countermeasures, although other significant associations should not be ignored. In accordance with findings from previous HFACS-based analyses of aviation and medical incidents, efforts to reduce the frequency of unsafe acts or operations should be directed to a few critical HFACS categories at the higher levels: organisational climate, planned inadequate operations, and inadequate supervision. While remedial strategies are proposed it is important that future efforts evaluate the utility of the measures proposed in studies of system safety. Copyright © 2011. Published by Elsevier Ltd.

  5. Study on the Accident-causing of Foundation Pit Engineering

    NASA Astrophysics Data System (ADS)

    Shuicheng, Tian; Xinyue, Zhang; Pengfei, Yang; Longgang, Chen

    2018-05-01

    With the development of high-rise buildings and underground space, a large number of foundation pit projects have occurred. Frequent accidents of it cause great losses to the society, how to reduce the frequency of pit accidents has become one of the most urgent problems to be solved. Therefore, analysing the influencing factors of foundation pit engineering accidents and studying the causes of foundation pit accidents, which of great significance for improving the safety management level of foundation pit engineering and reducing the incidence of foundation pit accidents. Firstly, based on literature review and questionnaires, this paper selected construction management, survey, design, construction, supervision and monitoring as research factors, we used the AHP method and the Dematel method to analyze the weights of various influencing factors to screen indicators to determine the ultimate system of accidents caused by foundation pit accidents; Secondly, SPSS 21.0 software was used to test the reliability and validity of the recovered questionnaire data. AMOS 7.0 software was used to fit, evaluate, and explain the set model; Finally, this paper analysed the influencing factors of foundation pit engineering accidents, corresponding management countermeasures and suggestions were put forward.

  6. PREFACE: 7th International Conference on 3D Radiation Dosimetry (IC3DDose)

    NASA Astrophysics Data System (ADS)

    Thwaites, David; Baldock, Clive

    2013-06-01

    IC3DDose 2013, the 7th International Conference on 3D Radiation Dosimetry held in Sydney, Australia from 4-8 November 2012, grew out of the DosGel series, which began as DosGel99, the 1st International Workshop on Radiation Therapy Gel Dosimetry in Lexington, Kentucky. Since 1999 subsequent DoSGel conferences were held in Brisbane, Australia (2001), Ghent, Belgium (2004), Sherbrooke, Canada (2006) and Crete, Greece (2008). In 2010 the conference was held on Hilton Head Island, South Carolina and underwent a name-change to IC3DDose. The aim of the first workshop was to bring together individuals, both researchers and users, with an interest in 3D radiation dosimetry techniques, with a mix of presentations from basic science to clinical applications, which has remained an objective for all of the meetings. One rationale of DosGel99 was stated as supporting the increasing clinical implementation of gel dosimetry, as the technique appeared, at that time, to be leaving the laboratories of gel dosimetry enthusiasts and entering clinical practice. Clearly by labelling the first workshop as the 1st, there was a vision of a continuing series, which has been fulfilled. On the other hand, the expectation of widespread clinical use of gel dosimetry has perhaps not been what was hoped for and anticipated. Nevertheless the rapidly increasing demand for advanced high-precision 3D radiotherapy technology and techniques has continued apace. The need for practical and accurate 3D dosimetry methods for development and quality assurance has only increased. By the 6th meeting, held in South Carolina in 2010, the Conference Scientific Committee recognised the wider developments in 3D systems and methods and decided to widen the scope, whilst keeping the same span from basic science to applications. This was signalled by a change of name from 'Dosgel' to 'IC3DDose', a name that has continued to this latest conference. The conference objectives were: to enhance the quality and accuracy of

  7. COMPARISON OF RESPONSE OF PASSIVE DOSIMETRY SYSTEMS IN SCANNING PROTON RADIOTHERAPY-A STUDY USING PAEDIATRIC ANTHROPOMORPHIC PHANTOMS.

    PubMed

    Kneževic, Ž; Ambrozova, I; Domingo, C; De Saint-Hubert, M; Majer, M; Martínez-Rovira, I; Miljanic, S; Mojzeszek, N; Porwol, P; Ploc, O; Romero-Expósito, M; Stolarczyk, L; Trinkl, S; Harrison, R M; Olko, P

    2017-11-18

    Proton beam therapy has advantages in comparison to conventional photon radiotherapy due to the physical properties of proton beams (e.g. sharp distal fall off, adjustable range and modulation). In proton therapy, there is the possibility of sparing healthy tissue close to the target volume. This is especially important when tumours are located next to critical organs and while treating cancer in paediatric patients. On the other hand, the interactions of protons with matter result in the production of secondary radiation, mostly neutrons and gamma radiation, which deposit their energy at a distance from the target. The aim of this study was to compare the response of different passive dosimetry systems in mixed radiation field induced by proton pencil beam inside anthropomorphic phantoms representing 5 and 10 years old children. Doses were measured in different organs with thermoluminescent (MTS-7, MTS-6 and MCP-N), radiophotoluminescent (GD-352 M and GD-302M), bubble and poly-allyl-diglycol carbonate (PADC) track detectors. Results show that RPL detectors are the less sensitive for neutrons than LiF TLDs and can be applied for in-phantom dosimetry of gamma component. Neutron doses determined using track detectors, bubble detectors and pairs of MTS-7/MTS-6 are consistent within the uncertainty range. This is the first study dealing with measurements on child anthropomorphic phantoms irradiated by a pencil scanning beam technique. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Edema and Seed Displacements Affect Intraoperative Permanent Prostate Brachytherapy Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Westendorp, Hendrik, E-mail: r.westendorp@radiotherapiegroep.nl; Nuver, Tonnis T.; Department of Radiation Oncology, Radiotherapiegroep Behandellocatie Deventer, Deventer

    Purpose: We sought to identify the intraoperative displacement patterns of seeds and to evaluate the correlation of intraoperative dosimetry with day 30 for permanent prostate brachytherapy. Methods and Materials: We analyzed the data from 699 patients. Intraoperative dosimetry was acquired using transrectal ultrasonography (TRUS) and C-arm cone beam computed tomography (CBCT). Intraoperative dosimetry (minimal dose to 40%-95% of the volume [D{sub 40}-D{sub 95}]) was compared with the day 30 dosimetry for both modalities. An additional edema-compensating comparison was performed for D{sub 90}. Stranded seeds were linked between TRUS and CBCT using an automatic and fast linking procedure. Displacement patterns weremore » analyzed for each seed implantation location. Results: On average, an intraoperative (TRUS to CBCT) D{sub 90} decline of 10.6% ± 7.4% was observed. Intraoperative CBCT D{sub 90} showed a greater correlation (R{sup 2} = 0.33) with respect to Day 30 than did TRUS (R{sup 2} = 0.17). Compensating for edema, the correlation increased to 0.41 for CBCT and 0.38 for TRUS. The mean absolute intraoperative seed displacement was 3.9 ± 2.0 mm. The largest seed displacements were observed near the rectal wall. The central and posterior seeds showed less caudal displacement than lateral and anterior seeds. Seeds that were implanted closer to the base showed more divergence than seeds close to the apex. Conclusions: Intraoperative CBCT D{sub 90} showed a greater correlation with the day 30 dosimetry than intraoperative TRUS. Edema seemed to cause most of the systematic difference between the intraoperative and day 30 dosimetry. Seeds near the rectal wall showed the most displacement, comparing TRUS and CBCT, probably because of TRUS probe–induced prostate deformation.« less

  9. Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents.

    PubMed

    Shi, Shenggang; Cao, Jingcan; Feng, Li; Liang, Wenyan; Zhang, Liqiu

    2014-07-15

    The environmental pollution resulting from chemical accidents has caused increasingly serious concerns. Therefore, it is very important to be able to determine in advance the appropriate emergency treatment and disposal technology for different types of chemical accidents. However, the formulation of an emergency plan for chemical pollution accidents is considerably difficult due to the substantial uncertainty and complexity of such accidents. This paper explains how the event tree method was used to create 54 different scenarios for chemical pollution accidents, based on the polluted medium, dangerous characteristics and properties of chemicals involved. For each type of chemical accident, feasible emergency treatment and disposal technology schemes were established, considering the areas of pollution source control, pollutant non-proliferation, contaminant elimination and waste disposal. Meanwhile, in order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs from the plan repository, the technique evaluation index system was developed based on group decision-improved analytical hierarchy process (AHP), and has been tested by using a sudden aniline pollution accident that occurred in a river in December 2012. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. TH-CD-201-05: Characterization of a Novel Light-Collimating Tank Optical-CT System for 3D Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miles, D; Yoon, S; Adamovics, J

    Purpose: Comprehensive 3D dosimetry is highly desirable for advanced clinical QA, but costly optical readout techniques have hindered widespread implementation. Here, we present the first results from a cost-effective Integrated-lens Dry-tank Optical Scanner (IDOS), designed for convenient 3D dosimetry readout of radiochromic plastic dosimeters (e.g. PRESAGE). Methods: The scanner incorporates a novel transparent light-collimating tank, which collimates a point light source into parallel-ray CT geometry. The tank was designed using an in-house Monte-Carlo optical ray-tracing simulation, and was cast in polyurethane using a 3D printed mould. IDOS spatial accuracy was evaluated by imaging a set of custom optical phantoms, withmore » comparison to x-ray CT images. IDOS dose measurement performance was assessed by imaging PRESAGE dosimeters irradiated with simple known dose distributions (e.g., 4 field box 6MV treatment with Varian Linac). Direct comparisons were made to images from our gold standard DLOS scanner and calculated dose distributions from a commissioned Eclipse planning system. Results: All optical CT images were reconstructed at 1mm isotropic resolution. Comparison of IDOS and x-ray CT images of the geometric phantom demonstrated excellent IDOS geometric accuracy (sub-mm) throughout the dosimeter. IDOS measured 3D dose distribution agreed well with prediction from Eclipse, with 95% gamma pass rate at 3%/3mm. Cross-scanner dose measurement gamma analysis shows >90% of pixels passing at 3%/3mm. Conclusion: The first prototype of the IDOS system has demonstrated promising performance, with accurate dosimeter readout and negligible spatial distortion. The use of optical simulations and 3D printing to create a light collimating-tank has dramatically increased convenience and reduced costs by removing the need for expensive lenses and large volumes of refractive matching fluids.« less

  11. Assessment of national dosimetry quality audits results for teletherapy machines from 1989 to 2015.

    PubMed

    Muhammad, Wazir; Ullah, Asad; Mahmood, Khalid; Matiullah

    2016-01-01

    The purpose of this study was to ensure accuracy in radiation dose delivery, external dosimetry quality audit has an equal importance with routine dosimetry performed at clinics. To do so, dosimetry quality audit was organized by the Secondary Standard Dosimetry Laboratory (SSDL) of Pakistan Institute of Nuclear Science and Technology (PINSTECH) at the national level to investigate and minimize uncertainties involved in the measurement of absorbed dose, and to improve the accuracy of dose measurement at different radiotherapy hospitals. A total of 181 dosimetry quality audits (i.e., 102 of Co-60 and 79 of linear accelerators) for teletherapy units installed at 22 different sites were performed from 1989 to 2015. The percent deviation between users’ calculated/stated dose and evaluated dose (in the result of on-site dosimetry visits) were calculated and the results were analyzed with respect to the limits of ± 2.5% (ICRU "optimal model") ± 3.0% (IAEA on-site dosimetry visits limit) and ± 5.0% (ICRU minimal or "lowest acceptable" model). The results showed that out of 181 total on-site dosimetry visits, 20.44%, 16.02%, and 4.42% were out of acceptable limits of ± 2.5% ± 3.0%, and ± 5.0%, respectively. The importance of a proper ongoing quality assurance program, recommendations of the followed protocols, and properly calibrated thermometers, pressure gauges, and humidity meters at radiotherapy hospitals are essential in maintaining consistency and uniformity of absorbed dose measurements for precision in dose delivery.

  12. Safety of high-speed guided ground transportation systems : collision avoidance and accident survivability : volume 3 : accident survivability

    DOT National Transportation Integrated Search

    1993-03-01

    This report is the third of four volumes concerned with developing safety guidelines and specifications for high-speed guided ground transportation (HSGGT) collision avoidance and accident survivability. The overall approach taken in this study is to...

  13. [Characterization of a diode system for in vivo dosimetry with electron beams].

    PubMed

    Ragona, R; Rossetti, V; Lucio, F; Anglesio, S; Giglioli, F R

    2001-10-01

    Current quality assurance regulation stresses the basic role of in vivo dosimetry. Our study evaluates the usefulness and reliability of semiconductor diodes in determining the electron absorbed dose. P-type EDE semiconductor detectors were irradiated with electron beams of different energies produced by a CGR Saturn Therac 20. The diode and ionization chamber response were compared, and effect of energy value, collimator opening, source skin distance and gantry angle on diode response was studied. Measurements show a maximum increment of about 20% in diode response increasing the beam energy (6-20 MeV). The response also increases with: collimator opening, reaching 5% with field sizes larger than 10x10 cm2 (with the exception of 20 MeV energy); SSD increase (with a maximum of 8% for 20 MeV); transversal gantry incidence, compared with the diode longitudinal axis; it does not affect the response in the interval of +/- 45 degrees. Absorbed dose attenuation at dmax, due to the presence of diode on the axis of the beam as a function of electron energy was also determined : the maximum attenuation value is 15% in 6 MeV electron beams. A dose calculation algorithm, taking into account diode response dependence was outlined. In vivo dosimetry was performed in 92 fields for 80 patients, with an agreement of +/-4 % (1 SD) between prescribed and measured dose. It is possible to use the EDE semiconductor detectors on a quality control program of dose delivery for electron beam therapy, but particular attention should be paid to the beam incidence angle and diode dose attenuation.

  14. Possibility of reducing costs of mining operations - economic aspects of workplace accidents

    NASA Astrophysics Data System (ADS)

    Duda, Adam

    2017-11-01

    The article presents methods of calculating costs of workplace accidents incurred by an employer, and the influence of the number and severity of accidents on changes in the amount of accident insurance contribution paid by an employer within the framework of the social security system.

  15. Evaluation and mitigation of potential errors in radiochromic film dosimetry due to film curvature at scanning.

    PubMed

    Palmer, Antony L; Bradley, David A; Nisbet, Andrew

    2015-03-08

    This work considers a previously overlooked uncertainty present in film dosimetry which results from moderate curvature of films during the scanning process. Small film samples are particularly susceptible to film curling which may be undetected or deemed insignificant. In this study, we consider test cases with controlled induced curvature of film and with film raised horizontally above the scanner plate. We also evaluate the difference in scans of a film irradiated with a typical brachytherapy dose distribution with the film naturally curved and with the film held flat on the scanner. Typical naturally occurring curvature of film at scanning, giving rise to a maximum height 1 to 2 mm above the scan plane, may introduce dose errors of 1% to 4%, and considerably reduce gamma evaluation passing rates when comparing film-measured doses with treatment planning system-calculated dose distributions, a common application of film dosimetry in radiotherapy. The use of a triple-channel dosimetry algorithm appeared to mitigate the error due to film curvature compared to conventional single-channel film dosimetry. The change in pixel value and calibrated reported dose with film curling or height above the scanner plate may be due to variations in illumination characteristics, optical disturbances, or a Callier-type effect. There is a clear requirement for physically flat films at scanning to avoid the introduction of a substantial error source in film dosimetry. Particularly for small film samples, a compression glass plate above the film is recommended to ensure flat-film scanning. This effect has been overlooked to date in the literature.

  16. Assessing accident phobia in mild traumatic brain injury: The Accident Fear Questionnaire.

    PubMed

    Sutherland, Jessica; Middleton, Jason; Ornstein, Tisha J; Lawson, Kerry; Vickers, Kristin

    2016-08-01

    Despite a documented prevalence of accident phobia in almost 40% of motor vehicle accident (MVA) survivors, the onset of accident phobia after traumatic brain injury (TBI) remains poorly understood. There is currently a body of knowledge about posttraumatic stress disorder (PTSD) in patients with TBI, but less is known about accident phobia following TBI, particularly in cases of mild TBI (mTBI). Accident phobia can impede safe return to driving or motor vehicle travel, inhibiting return to daily functioning. In addition, pain complaints have been found to correlate positively with postinjury anxiety disorders. The present study sought to determine the reliability and validity of the Accident Fear Questionnaire (AFQ), a measure used to assess accident phobia, in 72 patients with mTBI using secondary data analysis and the subsequent development of accident phobia postinjury. Furthermore, we sought to examine the impact of pain, anxiety, and depression complaints on the AFQ. Results reveal convergent validity and reliability in mTBI populations. Additionally, pain, anxiety, and depression measures were significantly correlated with scores on the AFQ. Psychometrically, the phobia avoidance subscale of the AFQ is a reliable measure for use with mTBI populations, although some limitations were found. In particular, the accident profile (AP) subscale was not found to be reliable or valid and could be eliminated from the AFQ. Collectively, the present study contributes to the small body of published literature evaluating accident phobia in patients with mTBI and the impact of pain on the development of postinjury anxiety disorders. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  17. Hot Cell Installation and Demonstration of the Severe Accident Test Station

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Linton, Kory D.; Burns, Zachary M.; Terrani, Kurt A.

    A Severe Accident Test Station (SATS) capable of examining the oxidation kinetics and accident response of irradiated fuel and cladding materials for design basis accident (DBA) and beyond design basis accident (BDBA) scenarios has been successfully installed and demonstrated in the Irradiated Fuels Examination Laboratory (IFEL), a hot cell facility at Oak Ridge National Laboratory. The two test station modules provide various temperature profiles, steam, and the thermal shock conditions necessary for integral loss of coolant accident (LOCA) testing, defueled oxidation quench testing and high temperature BDBA testing. The installation of the SATS system restores the domestic capability to examinemore » postulated and extended LOCA conditions on spent fuel and cladding and provides a platform for evaluation of advanced fuel and accident tolerant fuel (ATF) cladding concepts. This document reports on the successful in-cell demonstration testing of unirradiated Zircaloy-4. It also contains descriptions of the integral test facility capabilities, installation activities, and out-of-cell benchmark testing to calibrate and optimize the system.« less

  18. Hanford Internal Dosimetry Program Manual, PNL-MA-552

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2009-09-24

    This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP), which is operated by the Pacific Northwest National Laboratory.( ) for the U.S. Department of Energy Richland Operations Office, Office of River Protection and their Hanford Site contractors. The manual describes the roles of and relationships between the IDP and the radiation protection programs of the Hanford Site contractors. Recommendations and guidance are also provided for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs.

  19. An operational centre for managing major chemical industrial accidents.

    PubMed

    Kiranoudis, C T; Kourniotis, S P; Christolis, M; Markatos, N C; Zografos, K G; Giannouli, I M; Androutsopoulos, K N; Ziomas, I; Kosmidis, E; Simeonidis, P; Poupkou, N

    2002-01-28

    The most important characteristic of major chemical accidents, from a societal perspective, is their tendency to produce off-site effects. The extent and severity of the accident may significantly affect the population and the environment of the adjacent areas. Following an accident event, effort should be made to limit such effects. Management decisions should be based on rational and quantitative information based on the site specific circumstances and the possible consequences. To produce such information we have developed an operational centre for managing large-scale industrial accidents. Its architecture involves an integrated framework of geographical information system (GIS) and RDBMS technology systems equipped with interactive communication capabilities. The operational centre was developed for Windows 98 platforms, for the region of Thriasion Pedion of West Attica, where the concentration of industrial activity and storage of toxic chemical is immense within areas of high population density. An appropriate case study is given in order to illuminate the use and necessity of the operational centre.

  20. Dosimetry study for a new in vivo X-ray fluorescence (XRF) bone lead measurement system

    NASA Astrophysics Data System (ADS)

    Nie, Huiling; Chettle, David; Luo, Liqiang; O'Meara, Joanne

    2007-10-01

    A new 109Cd γ-ray induced bone lead measurement system has been developed to reduce the minimum detectable limit (MDL) of the system. The system consists of four 16 mm diameter detectors. It requires a stronger source compared to the "conventional" system. A dosimetry study has been performed to estimate the dose delivered by this system. The study was carried out by using human-equivalent phantoms. Three sets of phantoms were made to estimate the dose delivered to three age groups: 5-year old, 10-year old and adults. Three approaches have been applied to evaluate the dose: calculations, Monte Carlo (MC) simulations, and experiments. Experimental results and analytical calculations were used to validate MC simulation. The experiments were performed by placing Panasonic UD-803AS TLDs at different places in phantoms that representing different organs. Due to the difficulty of obtaining the organ dose and the whole body dose solely by experiments and traditional calculations, the equivalent dose and effective dose were calculated by MC simulations. The result showed that the doses delivered to the organs other than the targeted lower leg are negligibly small. The total effective doses to the three age groups are 8.45/9.37 μSv (female/male), 4.20 μSv, and 0.26 μSv for 5-year old, 10-year old and adult, respectively. An approval to conduct human measurements on this system has been received from the Research Ethics Board based on this research.

  1. Polybutadiene and Styrene-Butadiene rubbers for high-dose dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Oliveira, Lucas N.; Instituto de Pesquisas Energeticas e Nucleares -IPEN, Sao Paulo-SP; Vieira, Silvio L.

    2015-07-01

    Polybutadiene and Styrene-Butadiene are synthetical rubbers used widely for pneumatic tires manufacturing. In this research, the dosimeter characteristics of those rubbers were studied for application in high-dose dosimetry. The rubber samples were irradiated with doses of 10 Gy up to 10 kGy, using a {sup 60}Co Gamma Cell-220 system (dose rate of 1.089 kGy/h) and their readings were taken on a Fourier Transform Infrared Spectroscopy-FTIR system (model Frontier/Perkin Elmer). The ratios of two absorbance peaks were taken for each kind of rubber spectrum, Polybutadiene (1306/1130 cm{sup -1}) and Styrene-Butadiene (1449/1306 cm{sup -1}). The ratio calculated was used as the responsemore » to the irradiation, and is not uniform across the sample. From the results, it can be concluded for both rubbers: a) the dose-response curves may be useful for high-dose dosimetry (greater than 250 Gy); b) their response for reproducibility presented standard deviations lower than 2.5%; c) the relative sensitivity was higher for Styrene-Butadiene (1.86 kGy{sup -1}) than for Polybutadiene (1.81 kGy{sup -1}), d) for doses of 10 kGy to 200 kGy, there was no variation in the dosimetric response. Both types of rubber samples showed usefulness as high-dose dosimeters. (authors)« less

  2. Dosimetry analyses of the Ringhals 3 and 4 reactor pressure vessels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kulesza, J.A.; Fero, A.H.; Rouden, J.

    2011-07-01

    A comprehensive series of neutron dosimetry measurements consisting of surveillance capsules, reactor pressure vessel cladding samples, and ex-vessel neutron dosimetry has been analyzed and compared to the results of three-dimensional, cycle-specific neutron transport calculations for the Ringhals Unit 3 and Unit 4 reactors in Sweden. The comparisons show excellent agreement between calculations and measurements. The measurements also demonstrate that it is possible to perform retrospective dosimetry measurements using the {sup 93}Nb (n,n') {sup 93m}Nb reaction on samples of 18-8 austenitic stainless steel with only trace amounts of elemental niobium. (authors)

  3. The Importance of Dosimetry Standardization in Radiobiology

    PubMed Central

    Desrosiers, Marc; DeWerd, Larry; Deye, James; Lindsay, Patricia; Murphy, Mark K; Mitch, Michael; Macchiarini, Francesca; Stojadinovic, Strahinja; Stone, Helen

    2013-01-01

    Radiation dose is central to much of radiobiological research. Precision and accuracy of dose measurements and reporting of the measurement details should be sufficient to allow the work to be interpreted and repeated and to allow valid comparisons to be made, both in the same laboratory and by other laboratories. Despite this, a careful reading of published manuscripts suggests that measurement and reporting of radiation dosimetry and setup for radiobiology research is frequently inadequate, thus undermining the reliability and reproducibility of the findings. To address these problems and propose a course of action, the National Cancer Institute (NCI), the National Institute of Allergy and Infectious Diseases (NIAID), and the National Institute of Standards and Technology (NIST) brought together representatives of the radiobiology and radiation physics communities in a workshop in September, 2011. The workshop participants arrived at a number of specific recommendations as enumerated in this paper and they expressed the desirability of creating dosimetry standard operating procedures (SOPs) for cell culture and for small and large animal experiments. It was also felt that these SOPs would be most useful if they are made widely available through mechanism(s) such as the web, where they can provide guidance to both radiobiologists and radiation physicists, be cited in publications, and be updated as the field and needs evolve. Other broad areas covered were the need for continuing education through tutorials at national conferences, and for journals to establish standards for reporting dosimetry. This workshop did not address issues of dosimetry for studies involving radiation focused at the sub-cellular level, internally-administered radionuclides, biodosimetry based on biological markers of radiation exposure, or dose reconstruction for epidemiological studies. PMID:26401441

  4. Progress with the NCT international dosimetry exchange.

    PubMed

    Binns, P J; Riley, K J; Harling, O K; Auterinen, I; Marek, M; Kiger, W S

    2004-11-01

    The international collaboration that was organized to undertake a dosimetry exchange for purposes of combining clinical data from different facilities conducting neutron capture therapy has continued since its founding at the 9th ISNCT symposium in October 2000. The thrust towards accumulating physical dosimetry data for comparison between different participants has broadened to include facilities in Japan and the determination of spectral descriptions of different beams. Retrospective analysis of patient data from the Brookhaven Medical Research Reactor is also being considered for incorporation into this study to increase the pool of available data. Meanwhile the next essential phase of comparing measurements of visiting dosimetry groups with treatment plan calculations from the host institutes has commenced. Host centers from Petten, Finland and the Czech Republic in Europe and MIT in the USA have applied the regular calculations and clinical calibrations from their current clinical studies, to generate treatment plans in the large standard phantom used for measurements by visiting participants. These data have been exchanged between the participants and scaling factors to relate the separate dose components between the different institutes are being determined. Preliminary normalization of measured and calculated dosimetry for patients is nearing completion to enable the physical radiation doses that comprise a treatment prescription at a host institute to be directly related to the corresponding measured doses of a visiting group. This should serve as an impetus for the direct comparison of patient data although the clinical requirements for achieving this need to be clearly defined. This may necessitate more extensive comparisons of treatment planning calculations through the solution of test problems and clarification regarding the question of dose specification from treatment calculations in general.

  5. TH-A-204-00: Key Dosimetry Data - Impact of New ICRU Recommendations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    The ICRU is currently finalizing a report on key data for radiation dosimetry. This multi-year review has resulted in a number of recommendations regarding “fundamental” data that are used in dosimetry related to radiation therapy. This educational session will explain the background for the ICRU committee’s work, the content and conclusions of the report and the impact on outputs, including NIST primary standards, ADCL calibration coefficients and clinical reference dosimetry. Parameters and beam modalities potentially affected by this report include: The mean excitation energy, I, for graphite, air, and water, The average energy required to create an ion pair inmore » dry air (commonly referred to as W/e), The uncertainty in the determination of air kerma in kV xrays The absolute value of Co-60 and Cs-137 primary standards and the dissemination of calibration coefficients, The determination of air kerma strength for Ir-192 HDR brachytherapy sources Ion chamber kQ factors for linac MV beams Ion chamber kQ factors for proton beams. The changes in reference dosimetry that would result from adoption of the ICRU recommendations are of the order of 0.5% to 1%, an effect that will not impact clinical dose delivery but will be detectable in the clinical setting. This session will also outline how worldwide metrology is coordinated through the Convention of the Meter and therefore how the international dosimetry community will proceed with adopting these recommendations so that uniformity from country to country in reference dosimetry is maintained. Timelines and communications methods will also be discussed to ensure that users, such as clinical medical physicists, are not surprised when their chamber’s calibration coefficient apparently changes. Learning Objectives: Understand the background for the ICRU committee’s work on key dosimetry data. Understand the proposed changes to key data and the impacts on reference dosimetry. Understand the methodology and

  6. TH-A-204-01: Part I - Key Data for Ionizing-Radiation Dosimetry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Seltzer, S.

    The ICRU is currently finalizing a report on key data for radiation dosimetry. This multi-year review has resulted in a number of recommendations regarding “fundamental” data that are used in dosimetry related to radiation therapy. This educational session will explain the background for the ICRU committee’s work, the content and conclusions of the report and the impact on outputs, including NIST primary standards, ADCL calibration coefficients and clinical reference dosimetry. Parameters and beam modalities potentially affected by this report include: The mean excitation energy, I, for graphite, air, and water, The average energy required to create an ion pair inmore » dry air (commonly referred to as W/e), The uncertainty in the determination of air kerma in kV x-rays The absolute value of Co-60 and Cs-137 primary standards and the dissemination of calibration coefficients, The determination of air kerma strength for Ir-192 HDR brachytherapy sources Ion chamber kQ factors for linac MV beams Ion chamber kQ factors for proton beams. The changes in reference dosimetry that would result from adoption of the ICRU recommendations are of the order of 0.5% to 1%, an effect that will not impact clinical dose delivery but will be detectable in the clinical setting. This session will also outline how worldwide metrology is coordinated through the Convention of the Meter and therefore how the international dosimetry community will proceed with adopting these recommendations so that uniformity from country to country in reference dosimetry is maintained. Timelines and communications methods will also be discussed to ensure that users, such as clinical medical physicists, are not surprised when their chamber’s calibration coefficient apparently changes. Learning Objectives: Understand the background for the ICRU committee’s work on key dosimetry data. Understand the proposed changes to key data and the impacts on reference dosimetry. Understand the methodology and

  7. Overview of the U.S. DOE Accident Tolerant Fuel Development Program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jon Carmack; Frank Goldner; Shannon M. Bragg-Sitton

    2013-09-01

    The United States Fuel Cycle Research and Development Advanced Fuels Campaign has been given the responsibility to conduct research and development on enhanced accident tolerant fuels with the goal of performing a lead test assembly or lead test rod irradiation in a commercial reactor by 2022. The Advanced Fuels Campaign has defined fuels with enhanced accident tolerance as those that, in comparison with the standard UO2-Zircaloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining ormore » improving the fuel performance during normal operations and operational transients, as well as design-basis and beyond design-basis events. This paper provides an overview of the FCRD Accident Tolerant Fuel program. The ATF attributes will be presented and discussed. Attributes identified as potentially important to enhance accident tolerance include reduced hydrogen generation (resulting from cladding oxidation), enhanced fission product retention under severe accident conditions, reduced cladding reaction with high-temperature steam, and improved fuel-cladding interaction for enhanced performance under extreme conditions. To demonstrate the enhanced accident tolerance of candidate fuel designs, metrics must be developed and evaluated using a combination of design features for a given LWR design, potential improvements to that design, and the design of an advanced fuel/cladding system. The aforementioned attributes provide qualitative guidance for parameters that will be considered for fuels with enhanced accident tolerance. It may be unnecessary to improve in all attributes and it is likely that some attributes or combination of attributes provide meaningful gains in accident tolerance, while others may provide only marginal benefits. Thus, an initial step in program implementation will be the development of

  8. Severe accidents in the energy sector: comparative perspective.

    PubMed

    Hirschberg, Stefan; Burgherr, Peter; Spiekerman, Gerard; Dones, Roberto

    2004-07-26

    This paper addresses one of the controversial issues in the current comparative studies of the environmental and health impacts of energy systems, i.e. the treatment of severe accidents. The work covers technical aspects of severe accidents and thus primarily reflects an engineering perspective on the energy-related risk issues, though some social implications are also touched upon. The assessment concerns fossil energy sources (coal, oil and gas), nuclear power and hydro power. The scope is not limited to the power production (conversion) step of these energy chains but, whenever applicable, also includes exploration, extraction, transports, processing, storage and waste disposal. With the exception of the nuclear chain the focus of the work has been on the evaluation of the historical experience of accidents. The basis used for this evaluation is a comprehensive database ENSAD (Energy-related Severe Accident Database), established by the Paul Scherrer Institut (PSI). For hypothetical nuclear accidents the probabilistic technique has also been employed and extended to cover the assessment of economic consequences of such accidents. The broader picture obtained by coverage of full energy chains leads on the world-wide basis to aggregated immediate fatality rates being much higher for the fossil chains than what one would expect if only power plants were considered. Generally, the immediate fatality rates are for all considered energy carriers significantly higher for the non-OECD countries than for OECD countries. In the case of hydro and nuclear the difference is in fact dramatic. The presentation of results is not limited to the aggregated values specific for each energy chain. Also frequency-consequence curves are provided. They reflect implicitly the ranking based on the aggregated values but include also such information as the observed or predicted chain-specific maximum extents of damages. This perspective on severe accidents may lead to different system

  9. Ambulance traffic accidents in Taiwan.

    PubMed

    Chiu, Po-Wei; Lin, Chih-Hao; Wu, Chen-Long; Fang, Pin-Hui; Lu, Chien-Hsin; Hsu, Hsiang-Chin; Chi, Chih-Hsien

    2018-04-01

    Ambulance traffic accidents (ATAs) are the leading cause of occupation-related fatalities among emergency medical service (EMS) personnel. We aim to use the Taiwan national surveillance system to analyze the characteristics of ATAs and to assist EMS directors in developing policies governing ambulance operations. A retrospective, cross-sectional and largely descriptive study was conducted using Taiwan national traffic accidents surveillance data from January 1, 2011 to October 31, 2016. Among the 1,627,217 traffic accidents during the study period, 715 ATAs caused 8 deaths within 24 h and 1844 injured patients. On average, there was one ATA for every 8598 ambulance runs. Compared to overall traffic accidents, ATAs were 1.7 times more likely to result in death and 1.9 times more likely to have injured patients. Among the 715 ATAs, 8 (1.1%) ATAs were fatal and 707 (98.9%) were nonfatal. All 8 fatalities were associated with motorcycles. The urban areas were significantly higher than the rural areas in the annual number of ATAs (14.2 ± 7.3 [7.0-26.7] versus 3.1 ± 1.9 [0.5-8.4], p = 0.013), the number of ATA-associated fatalities per year (0.2 ± 0.2 [0.0-0.7] versus 0.1 ± 0.1 [0.0-0.2], p = 0.022), and the annual number of injured patients (who needed urgent hospital visits) in ATAs (19.4 ± 7.3 [10.5-30.9] versus 5.2 ± 3.8 [0.9-15.3], p < 0.001). The ATA-associated fatality rate in Taiwan was high, and all fatalities were associated with motorcycles. ATAs in a highly motorcycle-populated area may require further investigation. An ambulance traffic accident reporting system should be built to provide EMS policy guidance for ATA reduction and outcome improvements. Copyright © 2018. Published by Elsevier B.V.

  10. Preventing accidents

    DOT National Transportation Integrated Search

    2005-08-01

    As the most effective strategy for improving safety is to prevent accidents from occurring at all, the Volpe Center applies a broad range of research techniques and capabilities to determine causes and consequences of accidents and to identify, asses...

  11. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  12. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  13. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  14. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  15. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  16. Analysis of traffic accidents in Romania, 2009.

    PubMed

    Călinoiu, Geovana; Minca, Dana Galieta; Furtunescu, Florentina Ligia

    2012-01-01

    This paper aimed to underline the main consequences of traffic accidents in Romania 2009 and their associated causes or circumstances. We identified some problematic geographic areas, some critical months or moments of the day and also the most frequent causes; all these should become targets for the future planning. The current analysis provides some priority criteria for public health interventions. So, the future national road safety strategy should be in line with the EU objectives, but also with the national priorities. Romania is far away from the average EU target for 2010 of halving the death by traffic accidents registered in 2001. To describe the circumstances and the consequences related to traffic accidents registered in Romania, for the year 2009. An ecological study was conducted. The traffic accidents circumstances were analyzed in terms of magnitude, geographic space, time and cause. The consequences were analyzed as affected people and damaged cars. A total of 28,627 traffic accidents were registered in Romania during the year 2009. 2,796 people were killed and 27,968 were hospitalized and 42,443 cars were damaged. 3 of 4 accidents were caused by violations on behalf of the car drivers. Most common violations in car drivers were excess of speed and priority violations (52.4%). Among the pedestrians, 7 of 10 accidents were caused by illegal crossing. A higher number of accidents occurred during the summer months and during the evening hours (from 5.00 pm till 8.00 pm). The traffic accidents represent a real public health problem in Romania and a serious burden for the health system. The gap between Romania and the other EU member states needs to be diminished in the next decade. In this purpose, the future national road safety strategy should be in line with the EU objectives, but also with the national priorities. Research is needed to understand the causes and the socio-economical impact of traffic accidents and to define appropriate national

  17. SU-F-SPS-06: Implementation of a Back-Projection Algorithm for 2D in Vivo Dosimetry with An EPID System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hernandez Reyes, B; Rodriguez Perez, E; Sosa Aquino, M

    Purpose: To implement a back-projection algorithm for 2D dose reconstructions for in vivo dosimetry in radiation therapy using an Electronic Portal Imaging Device (EPID) based on amorphous silicon. Methods: An EPID system was used to calculate dose-response function, pixel sensitivity map, exponential scatter kernels and beam hardenig correction for the back-projection algorithm. All measurements were done with a 6 MV beam. A 2D dose reconstruction for an irradiated water phantom (30×30×30 cm{sup 3}) was done to verify the algorithm implementation. Gamma index evaluation between the 2D reconstructed dose and the calculated with a treatment planning system (TPS) was done. Results:more » A linear fit was found for the dose-response function. The pixel sensitivity map has a radial symmetry and was calculated with a profile of the pixel sensitivity variation. The parameters for the scatter kernels were determined only for a 6 MV beam. The primary dose was estimated applying the scatter kernel within EPID and scatter kernel within the patient. The beam hardening coefficient is σBH= 3.788×10{sup −4} cm{sup 2} and the effective linear attenuation coefficient is µAC= 0.06084 cm{sup −1}. The 95% of points evaluated had γ values not longer than the unity, with gamma criteria of ΔD = 3% and Δd = 3 mm, and within the 50% isodose surface. Conclusion: The use of EPID systems proved to be a fast tool for in vivo dosimetry, but the implementation is more complex that the elaborated for pre-treatment dose verification, therefore, a simplest method must be investigated. The accuracy of this method should be improved modifying the algorithm in order to compare lower isodose curves.« less

  18. A review of recent advances in optical fibre sensors for in vivo dosimetry during radiotherapy

    PubMed Central

    O'Keeffe, S; McCarthy, D; Woulfe, P; Grattan, M W D; Hounsell, A R; Sporea, D; Mihai, L; Vata, I; Leen, G

    2015-01-01

    This article presents an overview of the recent developments and requirements in radiotherapy dosimetry, with particular emphasis on the development of optical fibre dosemeters for radiotherapy applications, focusing particularly on in vivo applications. Optical fibres offer considerable advantages over conventional techniques for radiotherapy dosimetry, owing to their small size, immunity to electromagnetic interferences, and suitability for remote monitoring and multiplexing. The small dimensions of optical fibre-based dosemeters, together with being lightweight and flexible, mean that they are minimally invasive and thus particularly suited to in vivo dosimetry. This means that the sensor can be placed directly inside a patient, for example, for brachytherapy treatments, the optical fibres could be placed in the tumour itself or into nearby critical tissues requiring monitoring, via the same applicators or needles used for the treatment delivery thereby providing real-time dosimetric information. The article outlines the principal sensor design systems along with some of the main strengths and weaknesses associated with the development of these techniques. The successful demonstration of these sensors in a range of different clinical environments is also presented. PMID:25761212

  19. Implementation of IMRT and VMAT using Delta4 phantom and portal dosimetry as dosimetry verification tools

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Daci, Lulzime, E-mail: lulzime.daci@nodlandssykehuset.no; Malkaj, Partizan, E-mail: malkaj-p@hotmail.com

    2016-03-25

    In this study we analyzed and compared the dose distribution of different IMRT and VMAT plans with the intent to provide pre-treatment quality assurance using two different tools. Materials/Methods: We have used the electronic portal imaging device EPID after calibration to dose and correction for the background offset signal and also the Delta4 phantom after en evaluation of angular sensitivity. The Delta4 phantom has a two-dimensional array with ionization chambers. We analyzed three plans for each anatomical site calculated by Eclipse treatment planning system. The measurements were analyzed using γ-evaluation method with passing criteria 3% absolute dose and 3 mm distancemore » to agreement (DTA). For all the plans the range of score has been from 97% to 99% for gantry fixed at 0° while for rotational planes there was a slightly decreased pass rates and above 95%. Point measurement with a ionization chamber were done in additional to see the accuracy of portal dosimetry and to evaluate the Delta4 device to various dose rates. Conclusions: Both Delt4 and Portal dosimetry shows good results between the measured and calculated doses. While Delta4 is more accurate in measurements EPID is more time efficient. We have decided to use both methods in the first steps of IMRT and VMAT implementation and later on to decide which of the tools to use depending on the complexity of plans, how much accurate we want to be and the time we have on the machine.« less

  20. Occupational accidents aboard merchant ships

    PubMed Central

    Hansen, H; Nielsen, D; Frydenberg, M

    2002-01-01

    Objectives: To investigate the frequency, circumstances, and causes of occupational accidents aboard merchant ships in international trade, and to identify risk factors for the occurrence of occupational accidents as well as dangerous working situations where possible preventive measures may be initiated. Methods: The study is a historical follow up on occupational accidents among crew aboard Danish merchant ships in the period 1993–7. Data were extracted from the Danish Maritime Authority and insurance data. Exact data on time at risk were available. Results: A total of 1993 accidents were identified during a total of 31 140 years at sea. Among these, 209 accidents resulted in permanent disability of 5% or more, and 27 were fatal. The mean risk of having an occupational accident was 6.4/100 years at sea and the risk of an accident causing a permanent disability of 5% or more was 0.67/100 years aboard. Relative risks for notified accidents and accidents causing permanent disability of 5% or more were calculated in a multivariate analysis including ship type, occupation, age, time on board, change of ship since last employment period, and nationality. Foreigners had a considerably lower recorded rate of accidents than Danish citizens. Age was a major risk factor for accidents causing permanent disability. Change of ship and the first period aboard a particular ship were identified as risk factors. Walking from one place to another aboard the ship caused serious accidents. The most serious accidents happened on deck. Conclusions: It was possible to clearly identify work situations and specific risk factors for accidents aboard merchant ships. Most accidents happened while performing daily routine duties. Preventive measures should focus on workplace instructions for all important functions aboard and also on the prevention of accidents caused by walking around aboard the ship. PMID:11850550