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Sample records for radiological source term

  1. Source term and radiological consequences of the Chernobyl accident

    SciTech Connect

    Mourad, R.; Snell, V.

    1987-01-01

    The objective of this work is to assess the source term and to evaluate the maximum hypothetical individual doses in European countries (including the Soviet Union) from the Chernobyl accident through the analyses of measurements of meteorological data, radiation fields, and airborne and deposited activity in these countries. Applying this information to deduce the source term involves a reversal of the techniques of nuclear accident analysis, which estimate the off-site consequences of postulated accidents. In this study the authors predict the quantities of radionuclides that, if released at Chernobyl and following the calculated trajectories, would explain and unify the observed radiation levels and radionuclide concentrations as measured by European countries and the Soviet Union. The simulation uses the PEAR microcomputer program following the methodology described in Canadian Standards Association standard N288.2. The study was performed before the Soviets published their estimate of the source term and the two results are compared.

  2. Radiological Source Terms for Tank Farms Safety Analysis

    SciTech Connect

    COWLEY, W.L.

    2000-06-27

    This document provides Unit Liter Dose factors, atmospheric dispersion coefficients, breathing rates and instructions for using and customizing these factors for use in calculating radiological doses for accident analyses in the Hanford Tank Farms.

  3. Challenges in defining a radiologic and hydrologic source term for underground nuclear test centers, Nevada Test Site, Nye County, Nevada

    SciTech Connect

    Smith, D.K.

    1995-06-01

    The compilation of a radionuclide inventory for long-lived radioactive contaminants residual from nuclear testing provides a partial measure of the radiologic source term at the Nevada Test Site. The radiologic source term also includes potentially mobile short-lived radionuclides excluded from the inventory. The radiologic source term for tritium is known with accuracy and is equivalent to the hydrologic source term within the saturated zone. Definition of the total hydrologic source term for fission and activation products that have high activities for decades following underground testing involves knowledge and assumptions which are presently unavailable. Systematic investigation of the behavior of fission products, activation products and actinides under saturated or Partially saturated conditions is imperative to define a representative total hydrologic source term. This is particularly important given the heterogeneous distribution of radionuclides within testing centers. Data quality objectives which emphasize a combination of measurements and credible estimates of the hydrologic source term are a priority for near-field investigations at the Nevada Test Site.

  4. Analysis of the Variability of Classsified and Unclassified Radiological Source term Inventories in the Frenchman Flat Area, Nevada test Site

    SciTech Connect

    Zhao, P; Zavarin, M

    2008-06-04

    It has been proposed that unclassified source terms used in the reactive transport modeling investigations at NTS CAUs should be based on yield-weighted source terms calculated using the average source term from Bowen et al. (2001) and the unclassified announced yields reported in DOE/NV-209. This unclassified inventory is likely to be used in unclassified contaminant boundary calculations and is, thus, relevant to compare to the classified inventory. They have examined the classified radionuclide inventory produced by 10 underground nuclear tests conducted in the Frenchman Flat (FF) area of the Nevada Test Site. The goals were to (1) evaluate the variability in classified radiological source terms among the 10 tests and (2) compare that variability and inventory uncertainties to an average unclassified inventory (e.g. Bowen 2001). To evaluate source term variability among the 10 tests, radiological inventories were compared on two relative scales: geometric mean and yield-weighted geometric mean. Furthermore, radiological inventories were either decay corrected to a common date (9/23/1992) or the time zero (t{sub 0}) of each test. Thus, a total of four data sets were produced. The date of 9/23/1992 was chosen based on the date of the last underground nuclear test at the Nevada Test Site.

  5. ACT-ARA: Code System for the Calculation of Changes in Radiological Source Terms with Time

    Energy Science and Technology Software Center (ESTSC)

    1988-02-01

    The program calculates the source term activity as a function of time for parent isotopes as well as daughters. Also, at each time, the "probable release" is produced. Finally, the program determines the time integrated probable release for each isotope over the time period of interest.

  6. ACT: a program for calculation of the changes in radiological source terms with time

    SciTech Connect

    Woolfolk, S.W.

    1985-08-12

    The program ACT calculates the source term activity from a set of initial activities as a function of discrete time steps. This calculation considers inbreeding of daughter products. ACT also calculates ''Probable Release'', which is the activity at a given time multiplied by both the fraction released and the probability of the release. The ''Probable Release'' not only assumes that the fraction released is a single step function with time, but that the probability of release is zero for a limited period and it can be described by the ''Wisconsin Regression'' function using time as the independent variable. Finally, the program calculates the time integrated sum of the ''Probable Release'' for each isotope. This program is intended to support analysis of releases from radioactive waste disposal sites such as those required by 40 CFR 191.

  7. Analysis of the Variability of Classified and Unclassified Radiological Source term Inventories in the Rainier Mesa/Shoshone Mountain Area, Nevada Test Site

    SciTech Connect

    Zhao, P; Zavarin, M

    2008-06-04

    It has been proposed that unclassified source terms used in RM/SM reactive transport modeling investigations should be based on yield-weighted source terms calculated using the RM/SM average source term from Bowen et al. (2001) and the unclassified announced yields reported in DOE/NV-209. This unclassified inventory is likely to be used in unclassified contaminant boundary calculations and is, thus, relevant to compare to the classified inventory. They have examined the classified radionuclide inventory produced by 73 underground nuclear tests conducted in the Rainier Mesa/Shoshone Mountain (RM/SM) area of the Nevada Test Site. The goals were to (1) evaluate the variability in classified radiological source terms among the 73 tests and (2) and compare that variability and inventory uncertainties to an average unclassified inventory (e.g. Bowen 2001). To evaluate source term variability among the 73 tests, radiological inventories were compared on two relative scales: geometric mean and yield-weighted geometric mean. Furthermore, radiological inventories were either decay corrected to a common date (9/23/1992) or the time zero (t{sub 0}) of each test. Thus, a total of four data sets were produced. The date of 9/23/1992 was chosen based on the date of the last underground nuclear test at the Nevada Test Site.

  8. International Data on Radiological Sources

    SciTech Connect

    Martha Finck; Margaret Goldberg

    2010-07-01

    ABSTRACT The mission of radiological dispersal device (RDD) nuclear forensics is to identify the provenance of nuclear and radiological materials used in RDDs and to aid law enforcement in tracking nuclear materials and routes. The application of databases to radiological forensics is to match RDD source material to a source model in the database, provide guidance regarding a possible second device, and aid the FBI by providing a short list of manufacturers and distributors, and ultimately to the last legal owner of the source. The Argonne/Idaho National Laboratory RDD attribution database is a powerful technical tool in radiological forensics. The database (1267 unique vendors) includes all sealed sources and a device registered in the U.S., is complemented by data from the IAEA Catalogue, and is supported by rigorous in-lab characterization of selected sealed sources regarding physical form, radiochemical composition, and age-dating profiles. Close working relationships with global partners in the commercial sealed sources industry provide invaluable technical information and expertise in the development of signature profiles. These profiles are critical to the down-selection of potential candidates in either pre- or post- event RDD attribution. The down-selection process includes a match between an interdicted (or detonated) source and a model in the database linked to one or more manufacturers and distributors.

  9. Apparatus for safeguarding a radiological source

    SciTech Connect

    Bzorgi, Fariborz M

    2014-10-07

    A tamper detector is provided for safeguarding a radiological source that is moved into and out of a storage location through an access porthole for storage and use. The radiological source is presumed to have an associated shipping container approved by the U.S. Nuclear Regulatory Commission for transporting the radiological source. The tamper detector typically includes a network of sealed tubing that spans at least a portion of the access porthole. There is an opening in the network of sealed tubing that is large enough for passage therethrough of the radiological source and small enough to prevent passage therethrough of the associated shipping cask. Generally a gas source connector is provided for establishing a gas pressure in the network of sealed tubing, and a pressure drop sensor is provided for detecting a drop in the gas pressure below a preset value.

  10. Chernobyl source term estimation

    SciTech Connect

    Gudiksen, P.H.; Harvey, T.F.; Lange, R.

    1990-09-01

    The Chernobyl source term available for long-range transport was estimated by integration of radiological measurements with atmospheric dispersion modeling and by reactor core radionuclide inventory estimation in conjunction with WASH-1400 release fractions associated with specific chemical groups. The model simulations revealed that the radioactive cloud became segmented during the first day, with the lower section heading toward Scandinavia and the upper part heading in a southeasterly direction with subsequent transport across Asia to Japan, the North Pacific, and the west coast of North America. By optimizing the agreement between the observed cloud arrival times and duration of peak concentrations measured over Europe, Japan, Kuwait, and the US with the model predicted concentrations, it was possible to derive source term estimates for those radionuclides measured in airborne radioactivity. This was extended to radionuclides that were largely unmeasured in the environment by performing a reactor core radionuclide inventory analysis to obtain release fractions for the various chemical transport groups. These analyses indicated that essentially all of the noble gases, 60% of the radioiodines, 40% of the radiocesium, 10% of the tellurium and about 1% or less of the more refractory elements were released. These estimates are in excellent agreement with those obtained on the basis of worldwide deposition measurements. The Chernobyl source term was several orders of magnitude greater than those associated with the Windscale and TMI reactor accidents. However, the {sup 137}Cs from the Chernobyl event is about 6% of that released by the US and USSR atmospheric nuclear weapon tests, while the {sup 131}I and {sup 90}Sr released by the Chernobyl accident was only about 0.1% of that released by the weapon tests. 13 refs., 2 figs., 7 tabs.

  11. External funding sources for radiology equipment.

    PubMed

    Rayburn, J D

    1988-01-01

    External funding sources are available to your organization for the purchase of radiology equipment, yet they often remain untapped because organizations do not believe they are eligible. This article provides an introduction to the procedure for seeking such funds. Basic terminology, the three major sources for funding, and some examples of foundation awards are presented. PMID:3357928

  12. Advanced Neutron Source radiological design criteria

    SciTech Connect

    Westbrook, J.L.

    1995-08-01

    The operation of the proposed Advanced Neutron Source (ANS) facility will present a variety of radiological protection problems. Because it is desired to design and operate the ANS according to the applicable licensing standards of the Nuclear Regulatory Commission (NRC), it must be demonstrated that the ANS radiological design basis is consistent not only with state and Department of Energy (DOE) and other usual federal regulations, but also, so far as is practicable, with NRC regulations and with recommendations of such organizations as the Institute of Nuclear Power Operations (INPO) and the Electric Power Research Institute (EPRI). Also, the ANS radiological design basis is in general to be consistent with the recommendations of authoritative professional and scientific organizations, specifically the National Council on Radiation Protection and Measurements (NCRP) and the International Commission on Radiological Protection (ICRP). As regards radiological protection, the principal goals of DOE regulations and guidance are to keep occupational doses ALARA [as low as (is) reasonably achievable], given the current state of technology, costs, and operations requirements; to control and monitor contained and released radioactivity during normal operation to keep public doses and releases to the environment ALARA; and to limit doses to workers and the public during accident conditions. Meeting these general design objectives requires that principles of dose reduction and of radioactivity control by employed in the design, operation, modification, and decommissioning of the ANS. The purpose of this document is to provide basic radiological criteria for incorporating these principles into the design of the ANS. Operations, modification, and decommissioning will be covered only as they are affected by design.

  13. Approximate factorization with source terms

    NASA Technical Reports Server (NTRS)

    Shih, T. I.-P.; Chyu, W. J.

    1991-01-01

    A comparative evaluation is made of three methodologies with a view to that which offers the best approximate factorization error. While two of these methods are found to lead to more efficient algorithms in cases where factors which do not contain source terms can be diagonalized, the third method used generates the lowest approximate factorization error. This method may be preferred when the norms of source terms are large, and transient solutions are of interest.

  14. Verification of Minimum Detectable Activity for Radiological Threat Source Search

    NASA Astrophysics Data System (ADS)

    Gardiner, Hannah; Myjak, Mitchell; Baciak, James; Detwiler, Rebecca; Seifert, Carolyn

    2015-10-01

    The Department of Homeland Security's Domestic Nuclear Detection Office is working to develop advanced technologies that will improve the ability to detect, localize, and identify radiological and nuclear sources from airborne platforms. The Airborne Radiological Enhanced-sensor System (ARES) program is developing advanced data fusion algorithms for analyzing data from a helicopter-mounted radiation detector. This detector platform provides a rapid, wide-area assessment of radiological conditions at ground level. The NSCRAD (Nuisance-rejection Spectral Comparison Ratios for Anomaly Detection) algorithm was developed to distinguish low-count sources of interest from benign naturally occurring radiation and irrelevant nuisance sources. It uses a number of broad, overlapping regions of interest to statistically compare each newly measured spectrum with the current estimate for the background to identify anomalies. We recently developed a method to estimate the minimum detectable activity (MDA) of NSCRAD in real time. We present this method here and report on the MDA verification using both laboratory measurements and simulated injects on measured backgrounds at or near the detection limits. This work is supported by the US Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract/IAA HSHQDC-12-X-00376. This support does not constitute an express or implied endorsement on the part of the Gov't.

  15. BWR Source Term Generation and Evaluation

    SciTech Connect

    J.C. Ryman

    2003-07-31

    This calculation is a revision of a previous calculation (Ref. 7.5) that bears the same title and has the document identifier BBAC00000-01717-0210-00006 REV 01. The purpose of this revision is to remove TBV (to-be-verified) -41 10 associated with the output files of the previous version (Ref. 7.30). The purpose of this and the previous calculation is to generate source terms for a representative boiling water reactor (BWR) spent nuclear fuel (SNF) assembly for the first one million years after the SNF is discharged from the reactors. This calculation includes an examination of several ways to represent BWR assemblies and operating conditions in SAS2H in order to quantify the effects these representations may have on source terms. These source terms provide information characterizing the neutron and gamma spectra in particles per second, the decay heat in watts, and radionuclide inventories in curies. Source terms are generated for a range of burnups and enrichments (see Table 2) that are representative of the waste stream and stainless steel (SS) clad assemblies. During this revision, it was determined that the burnups used for the computer runs of the previous revision were actually about 1.7% less than the stated, or nominal, burnups. See Section 6.6 for a discussion of how to account for this effect before using any source terms from this calculation. The source term due to the activation of corrosion products deposited on the surfaces of the assembly from the coolant is also calculated. The results of this calculation support many areas of the Monitored Geologic Repository (MGR), which include thermal evaluation, radiation dose determination, radiological safety analyses, surface and subsurface facility designs, and total system performance assessment. This includes MGR items classified as Quality Level 1, for example, the Uncanistered Spent Nuclear Fuel Disposal Container (Ref. 7.27, page 7). Therefore, this calculation is subject to the requirements of the

  16. Status of ion sources at National Institute of Radiological Sciences

    SciTech Connect

    Kitagawa, A.; Fujita, T.; Goto, A.; Hattori, T.; Hamano, T.; Hojo, S.; Honma, T.; Imaseki, H.; Katagiri, K.; Muramatsu, M.; Sakamoto, Y.; Sekiguchi, M.; Suda, M.; Sugiura, A.; Suya, N.

    2012-02-15

    The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements.

  17. HTGR Mechanistic Source Terms White Paper

    SciTech Connect

    Wayne Moe

    2010-07-01

    The primary purposes of this white paper are: (1) to describe the proposed approach for developing event specific mechanistic source terms for HTGR design and licensing, (2) to describe the technology development programs required to validate the design methods used to predict these mechanistic source terms and (3) to obtain agreement from the NRC that, subject to appropriate validation through the technology development program, the approach for developing event specific mechanistic source terms is acceptable

  18. Estimating Source Terms for Diverse Spent Nuclear Fuel Types

    SciTech Connect

    Brett Carlsen; Layne Pincock

    2004-11-01

    The U.S. Department of Energy (DOE) National Spent Nuclear Fuel Program is responsible for developing a defensible methodology for determining the radionuclide inventory for the DOE spent nuclear fuel (SNF) to be dispositioned at the proposed Monitored Geologic Repository at the Yucca Mountain Site. SNF owned by DOE includes diverse fuels from various experimental, research, and production reactors. These fuels currently reside at several DOE sites, universities, and foreign research reactor sites. Safe storage, transportation, and ultimate disposal of these fuels will require radiological source terms as inputs to safety analyses that support design and licensing of the necessary equipment and facilities. This paper summarizes the methodology developed for estimating radionuclide inventories associated with DOE-owned SNF. The results will support development of design and administrative controls to manage radiological risks and may later be used to demonstrate conformance with repository acceptance criteria.

  19. Calculation of source terms for NUREG-1150

    SciTech Connect

    Breeding, R.J.; Williams, D.C.; Murfin, W.B.; Amos, C.N.; Helton, J.C.

    1987-10-01

    The source terms estimated for NUREG-1150 are generally based on the Source Term Code Package (STCP), but the actual source term calculations used in computing risk are performed by much smaller codes which are specific to each plant. This was done because the method of estimating the uncertainty in risk for NUREG-1150 requires hundreds of source term calculations for each accident sequence. This is clearly impossible with a large, detailed code like the STCP. The small plant-specific codes are based on simple algorithms and utilize adjustable parameters. The values of the parameters appearing in these codes are derived from the available STCP results. To determine the uncertainty in the estimation of the source terms, these parameters were varied as specified by an expert review group. This method was used to account for the uncertainties in the STCP results and the uncertainties in phenomena not considered by the STCP.

  20. SOURCE TERMS FOR HLW GLASS CANISTERS

    SciTech Connect

    J.S. Tang

    2000-08-15

    This calculation is prepared by the Monitored Geologic Repository (MGR) Waste Package Design Section. The objective of this calculation is to determine the source terms that include radionuclide inventory, decay heat, and radiation sources due to gamma rays and neutrons for the high-level radioactive waste (HLW) from the, West Valley Demonstration Project (WVDP), Savannah River Site (SRS), Hanford Site (HS), and Idaho National Engineering and Environmental Laboratory (INEEL). This calculation also determines the source terms of the canister containing the SRS HLW glass and immobilized plutonium. The scope of this calculation is limited to source terms for a time period out to one million years. The results of this calculation may be used to carry out performance assessment of the potential repository and to evaluate radiation environments surrounding the waste packages (WPs). This calculation was performed in accordance with the Development Plan ''Source Terms for HLW Glass Canisters'' (Ref. 7.24).

  1. Mechanistic facility safety and source term analysis

    SciTech Connect

    PLYS, M.G.

    1999-06-09

    A PC-based computer program was created for facility safety and source term analysis at Hanford The program has been successfully applied to mechanistic prediction of source terms from chemical reactions in underground storage tanks, hydrogen combustion in double contained receiver tanks, and proccss evaluation including the potential for runaway reactions in spent nuclear fuel processing. Model features include user-defined facility room, flow path geometry, and heat conductors, user-defined non-ideal vapor and aerosol species, pressure- and density-driven gas flows, aerosol transport and deposition, and structure to accommodate facility-specific source terms. Example applications are presented here.

  2. STACE: Source Term Analyses for Containment Evaluations of transport casks

    SciTech Connect

    Seager, K. D.; Gianoulakis, S. E.; Barrett, P. R.; Rashid, Y. R.; Reardon, P. C.

    1992-01-01

    Following the guidance of ANSI N14.5, the STACE methodology provides a technically defensible means for estimating maximum permissible leakage rates. These containment criteria attempt to reflect the true radiological hazard by performing a detailed examination of the spent fuel, CRUD, and residual contamination contributions to the releasable source term. The evaluation of the spent fuel contribution to the source term has been modeled fairly accurately using the STACE methodology. The structural model predicts the cask drop load history, the mechanical response of the fuel assembly, and the probability of cladding breach. These data are then used to predict the amount of fission gas, volatile species, and fuel fines that are releasable from the cask. There are some areas where data are sparse or lacking (e.g., the quantity and size distribution of fuel rod breaches) in which experimental validation is planned. The CRUD spallation fraction is the major area where no quantitative data has been found; therefore, this also requires experimental validation. In the interim, STACE conservatively assumes a 100% spallation fraction for computing the releasable activity. The source term methodology also conservatively assumes that there is 1 Ci of residual contamination available for release in the transport cask. However, residual contamination is still by far the smallest contributor to the source term activity.

  3. The long-term problems of contaminated land: Sources, impacts and countermeasures

    SciTech Connect

    Baes, C.F. III

    1986-11-01

    This report examines the various sources of radiological land contamination; its extent; its impacts on man, agriculture, and the environment; countermeasures for mitigating exposures; radiological standards; alternatives for achieving land decontamination and cleanup; and possible alternatives for utilizing the land. The major potential sources of extensive long-term land contamination with radionuclides, in order of decreasing extent, are nuclear war, detonation of a single nuclear weapon (e.g., a terrorist act), serious reactor accidents, and nonfission nuclear weapons accidents that disperse the nuclear fuels (termed ''broken arrows'').

  4. Assessing sensitivity of source term estimation

    NASA Astrophysics Data System (ADS)

    Long, Kerrie J.; Haupt, Sue Ellen; Young, George S.

    2010-04-01

    Source term estimation algorithms compute unknown atmospheric transport and dispersion modeling variables from concentration observations made by sensors in the field. Insufficient spatial and temporal resolution in the meteorological data as well as inherent uncertainty in the wind field data make source term estimation and the prediction of subsequent transport and dispersion extremely difficult. This work addresses the question: how many sensors are necessary in order to successfully estimate the source term and meteorological variables required for atmospheric transport and dispersion modeling? The source term estimation system presented here uses a robust optimization technique - a genetic algorithm (GA) - to find the combination of source location, source height, source strength, surface wind direction, surface wind speed, and time of release that produces a concentration field that best matches the sensor observations. The approach is validated using the Gaussian puff as the dispersion model in identical twin numerical experiments. The limits of the system are tested by incorporating additive and multiplicative noise into the synthetic data. The minimum requirements for data quantity and quality are determined by an extensive grid sensitivity analysis. Finally, a metric is developed for quantifying the minimum number of sensors necessary to accurately estimate the source term and to obtain the relevant wind information.

  5. Evaluation of an open source tool for indexing and searching enterprise radiology and pathology reports

    NASA Astrophysics Data System (ADS)

    Kim, Woojin; Boonn, William

    2010-03-01

    Data mining of existing radiology and pathology reports within an enterprise health system can be used for clinical decision support, research, education, as well as operational analyses. In our health system, the database of radiology and pathology reports exceeds 13 million entries combined. We are building a web-based tool to allow search and data analysis of these combined databases using freely available and open source tools. This presentation will compare performance of an open source full-text indexing tool to MySQL's full-text indexing and searching and describe implementation procedures to incorporate these capabilities into a radiology-pathology search engine.

  6. Long term radiological effects of short term exposure to amosite asbestos among factory workers.

    PubMed Central

    Ehrlich, R; Lilis, R; Chan, E; Nicholson, W J; Selikoff, I J

    1992-01-01

    Chest radiographs were read from a sub-cohort of 386 factory workers with short term exposure to amosite asbestos (median exposure six months) and long follow up (median 25 years). Prevalence of abnormality was determined independently by two readers from the first film available after 20 years from first employment. Serial films were obtainable for 238 men (median interval from first to last film: nine years). Progression was classified with a direct progression scoring scale. Individual dust exposure estimates were derived from dust counts from two similar plants. With as little as one month or less of employment, about 20% of the films showed parenchymal abnormality and about a third showed pleural abnormality. Those in the lowest cumulative exposure stratum (less than 5 fibre-years/ml) were similarly found to have high rates of abnormality. Dose-response relations were present in the data of both readers. Smokers had higher rates of parenchymal abnormality. On multivariate analysis, cumulative exposure was the exposure variable most closely related to parenchymal abnormality, and time from first employment was the variable most closely related to pleural abnormality. Progression (including first attacks) 20 or more years after ceasing employment occurred and was more common for pleural than for parenchymal abnormality. It is concluded that with exposure to high concentrations to amosite such as existed in this factory and with follow up for at least 20 years, (1) exposure for as little as a month was sufficient to produce radiological signs of parenchymal and pleural fibrosis, (2) no cumulative exposure threshold for parenchymal and pleural fibrosis was detectable, and (3) parenchymal and pleural progression were still detectable >/= 20 years after the end of exposure. PMID:1315154

  7. Subsurface Shielding Source Term Specification Calculation

    SciTech Connect

    S.Su

    2001-04-12

    The purpose of this calculation is to establish appropriate and defensible waste-package radiation source terms for use in repository subsurface shielding design. This calculation supports the shielding design for the waste emplacement and retrieval system, and subsurface facility system. The objective is to identify the limiting waste package and specify its associated source terms including source strengths and energy spectra. Consistent with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M&O 2001, p. 15), the scope of work includes the following: (1) Review source terms generated by the Waste Package Department (WPD) for various waste forms and waste package types, and compile them for shielding-specific applications. (2) Determine acceptable waste package specific source terms for use in subsurface shielding design, using a reasonable and defensible methodology that is not unduly conservative. This calculation is associated with the engineering and design activity for the waste emplacement and retrieval system, and subsurface facility system. The technical work plan for this calculation is provided in CRWMS M&O 2001. Development and performance of this calculation conforms to the procedure, AP-3.12Q, Calculations.

  8. Sensitivities to source-term parameters of emergency planning zone boundaries for waste management facilities

    SciTech Connect

    Mueller, C.J.

    1995-07-01

    This paper reviews the key parameters comprising airborne radiological and chemical release source terms, discusses the ranges over which values of these parameters occur for plausible but severe waste management facility accidents, and relates the concomitant sensitivities of emergency planning zone boundaries predicted on calculated distances to early severe health effects.

  9. Radiological protection, safety and security issues in the industrial and medical applications of radiation sources

    NASA Astrophysics Data System (ADS)

    Vaz, Pedro

    2015-11-01

    The use of radiation sources, namely radioactive sealed or unsealed sources and particle accelerators and beams is ubiquitous in the industrial and medical applications of ionizing radiation. Besides radiological protection of the workers, members of the public and patients in routine situations, the use of radiation sources involves several aspects associated to the mitigation of radiological or nuclear accidents and associated emergency situations. On the other hand, during the last decade security issues became burning issues due to the potential malevolent uses of radioactive sources for the perpetration of terrorist acts using RDD (Radiological Dispersal Devices), RED (Radiation Exposure Devices) or IND (Improvised Nuclear Devices). A stringent set of international legally and non-legally binding instruments, regulations, conventions and treaties regulate nowadays the use of radioactive sources. In this paper, a review of the radiological protection issues associated to the use of radiation sources in the industrial and medical applications of ionizing radiation is performed. The associated radiation safety issues and the prevention and mitigation of incidents and accidents are discussed. A comprehensive discussion of the security issues associated to the global use of radiation sources for the aforementioned applications and the inherent radiation detection requirements will be presented. Scientific, technical, legal, ethical, socio-economic issues are put forward and discussed.

  10. Novel neutron sources at the Radiological Research Accelerator Facility.

    PubMed

    Xu, Yanping; Garty, Guy; Marino, Stephen A; Massey, Thomas N; Randers-Pehrson, Gerhard; Johnson, Gary W; Brenner, David J

    2012-03-16

    Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons.We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target.A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a Proton Microbeam, impinging on a thin lithium target near the threshold of the (7)Li(p,n)(7)Be reaction. This novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components. PMID:22545061

  11. Novel neutron sources at the Radiological Research Accelerator Facility

    DOE PAGESBeta

    Xu, Yanping; Garty, G.; Marino, S. A.; Massey, Thomas Neal; Johnson, G. W.; Randers-Pehrson, Gerhard; Brenner, D. J.

    2012-03-16

    Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will bemore » based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a proton microbeam, impinging on a thin lithium target near the threshold of the Li-7(p,n)Be-7 reaction. Lastly, this novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components.« less

  12. Novel neutron sources at the Radiological Research Accelerator Facility

    PubMed Central

    Xu, Yanping; Garty, Guy; Marino, Stephen A.; Massey, Thomas N.; Randers-Pehrson, Gerhard; Johnson, Gary W.; Brenner, David J.

    2012-01-01

    Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10–20 micron in diameter. This facility is based on a Proton Microbeam, impinging on a thin lithium target near the threshold of the 7Li(p,n)7Be reaction. This novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components. PMID:22545061

  13. Novel neutron sources at the Radiological Research Accelerator Facility

    SciTech Connect

    Xu, Yanping; Garty, G.; Marino, S. A.; Massey, Thomas Neal; Johnson, G. W.; Randers-Pehrson, Gerhard; Brenner, D. J.

    2012-03-16

    Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a proton microbeam, impinging on a thin lithium target near the threshold of the Li-7(p,n)Be-7 reaction. Lastly, this novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components.

  14. Novel neutron sources at the Radiological Research Accelerator Facility

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Garty, G.; Marino, S. A.; Massey, T. N.; Randers-Pehrson, G.; Johnson, G. W.; Brenner, D. J.

    2012-03-01

    Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a proton microbeam, impinging on a thin lithium target near the threshold of the 7Li(p,n)7Be reaction. This novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components.

  15. Radiology.

    PubMed

    Patel, Ketan; Wallace, Roxanne; Busconi, Brian D

    2011-04-01

    Hip and groin pain are a common complaint among athletes of all ages, and may result from an acute injury or from chronic, repetitive trauma. Hip injuries can be intraarticular, extraarticular, or both. Labral abnormalities may occur in asymptomatic patients as well as in those with incapacitating symptoms and signs. Athletic hip injury leading to disabling intraarticular hip pain most commonly involves labral tear. The extraarticular causes are usually the result of overuse activity, leading to inflammation, tendonitis, or bursitis. In clinical practice, the term athletic pubalgia is used to describe exertional pubic or groin pain. PMID:21419955

  16. U.S.-CHINA RADIOLOGICAL SOURCE SECURITY PROJECT: CONTINUING AND EXPANDING BILATERAL COOPERATION

    SciTech Connect

    Zhu, Zhixuan; Zhou, Qifu; Yang, Yaoyun; Huang, Chaoyun; Lloyd, James; Williams, Adam; Feldman, Alexander; Streeper, Charles; Pope, Noah G.; Hawk, Mark; Rawl, Rick; Howell, Randy A.; Kennedy, Catherine

    2009-10-07

    The successful radiological security cooperation between the U.S. and China to secure at-risk sites near venues of the 2008 Beijing Summer Olympics has led to an expanded bilateral nonproliferation cooperation scope. The U.S. Department of Energy’s National Nuclear Security Administration, the Chinese Atomic Energy Authority and the China Ministry of Environmental Protection are continuing joint efforts to secure radiological sources throughout China under the U.S.-China Peaceful Uses of Nuclear Technology (PUNT) Agreement. Joint cooperation activities include physical security upgrades of sites with International Atomic Energy Agency (IAEA) Category 1 radiological sources, packaging, recovery, and storage of high activity transuranic and beta gamma sources, and secure transportation practices for the movement of recovered sources. Expansion of cooperation into numerous provinces within China includes the use of integrated training workshops that will demonstrate methodologies and best practices between U.S. and Chinese radiological source security and recovery experts. The fiscal year 2009 expanded scope of cooperation will be conducted similar to the 2008 Olympic cooperation with the Global Threat Reduction Initiative taking the lead for the U.S., PUNT being the umbrella agreement, and Los Alamos, Sandia, and Oak Ridge National Laboratories operating as technical working groups. This paper outlines the accomplishments of the joint implementation and training efforts to date and discusses the possible impact on future U.S./China cooperation.

  17. Hazardous constituent source term. Revision 2

    SciTech Connect

    Not Available

    1994-11-17

    The Department of Energy (DOE) has several facilities that either generate and/or store transuranic (TRU)-waste from weapons program research and production. Much of this waste also contains hazardous waste constituents as regulated under Subtitle C of the Resource Conservation and Recovery Act (RCRA). Toxicity characteristic metals in the waste principally include lead, occurring in leaded rubber gloves and shielding. Other RCRA metals may occur as contaminants in pyrochemical salt, soil, debris, and sludge and solidified liquids, as well as in equipment resulting from decontamination and decommissioning activities. Volatile organic compounds (VOCS) contaminate many waste forms as a residue adsorbed on surfaces or occur in sludge and solidified liquids. Due to the presence of these hazardous constituents, applicable disposal regulations include land disposal restrictions established by Hazardous and Solid Waste Amendments (HSWA). The DOE plans to dispose of TRU-mixed waste from the weapons program in the Waste Isolation Pilot Plant (WIPP) by demonstrating no-migration of hazardous constituents. This paper documents the current technical basis for methodologies proposed to develop a post-closure RCRA hazardous constituent source term. For the purposes of demonstrating no-migration, the hazardous constituent source term is defined as the quantities of hazardous constituents that are available for transport after repository closure. Development of the source term is only one of several activities that will be involved in the no-migration demonstration. The demonstration will also include uncertainty and sensitivity analyses of contaminant transport.

  18. DWPF Algorithm for Calculation of Source Terms and Consequences for EXCEL

    Energy Science and Technology Software Center (ESTSC)

    1997-02-11

    The DWPFAST software application algorithm is an Excel spreadsheet, with optional macros, designed to calculate the radiological source terms and consequences due to postulated accident progressions in non-reactor nuclear facilities (currently it is being used for DWPF). Upon input of a multi-character accident progression identification code, and basic facility data, the algorithm calculates individual accident segment releases, overall facility releases, and radiological consequences for various receptors, for up to 13 individual radionuclides. The algorithm wasmore » designed to support probabilistic safety assements (PSAs).« less

  19. IMPACTS OF SOURCE TERM HETEROGENEITIES ON WATER PATHWAY DOSE.

    SciTech Connect

    SULLIVAN, T.; GUSKOV, A.; POSKAS, P.; RUPERTI, N.; HANUSIK, V.; ET AL.

    2004-09-15

    and for which a solution has to be found in term of long-term disposal. Together with their casing and packaging, they are one form of heterogeneous waste; many other forms of waste with heterogeneous properties exist. They may arise in very small quantities and with very specific characteristics in the case of small producers, or in larger streams with standard characteristics in others. This wide variety of waste induces three main different levels of waste heterogeneity: (1) hot spot (e.g. disused sealed sources); (2) large item inside a package (e.g. metal components); and (3) very large items to be disposed of directly in the disposal unit (e.g. irradiated pipes, vessels). Safety assessments generally assume a certain level of waste homogeneity in most of the existing or proposed disposal facilities. There is a need to evaluate the appropriateness of such an assumption and the influence on the results of safety assessment. This need is especially acute in the case of sealed sources. There are many cases where are storage conditions are poor, or there is improper management leading to a radiological accident, some with significant or detrimental impacts. Disposal in a near surface disposal facility has been used in the past for some disused sealed sources. This option is currently in use for others sealed sources, or is being studied for the rest of them. The regulatory framework differs greatly between countries. In some countries, large quantities of disused sealed sources have been disposed of without any restriction, in others their disposal is forbidden by law. In any case, evaluation of the acceptability of disposal of disused sealed sources in near surface disposal facility is of utmost importance.

  20. RadSTraM: Radiological Source Tracking and Monitoring, Phase II Final Report

    SciTech Connect

    Warren, Tracy A; Walker, Randy M; Hill, David E; Gross, Ian G; Smith, Cyrus M; Abercrombie, Robert K

    2008-12-01

    This report focuses on the technical information gained from the Radiological Source Tracking and Monitoring (RadSTraM) Phase II investigation and its implications. The intent of the RadSTraM project was to determine the feasibility of tracking radioactive materials in commerce, particularly International Atomic Energy Agency (IAEA) Category 3 and 4 materials. Specifically, Phase II of the project addressed tracking radiological medical isotopes in commerce. These categories of materials are susceptible to loss or theft but the problem is not being addressed by other agencies.

  1. Uncertainties associated with the definition of a hydrologic source term for the Nevada Test Site

    SciTech Connect

    Smith, D.K.; Esser, B.K.; Thompson, J.L.

    1995-05-01

    The U.S. Department of Energy, Nevada Operations Office (DOE/NV) Environmental Restoration Division is seeking to evaluate groundwater contamination resulting from 30 years of underground nuclear testing at the Nevada Test Site (NTS). This evaluation requires knowledge about what radioactive materials are in the groundwater and how they are transported through the underground environment. This information coupled with models of groundwater flow (flow paths and flow rates) will enable predictions of the arrival of each radionuclide at a selected receptor site. Risk assessment models will then be used to calculate the expected environmental and human doses. The accuracy of our predictions depends on the validity of our hydrologic and risk assessment models and on the quality of the data for radionuclide concentrations in ground water at each underground nuclear test site. This paper summarizes what we currently know about radioactive material in NTS groundwater and suggests how we can best use our limited knowledge to proceed with initial modeling efforts. The amount of a radionuclide available for transport in groundwater at the site of an underground nuclear test is called the hydrologic source term. The radiologic source term is the total amount of residual radionuclides remaining after an underground nuclear test. The hydrologic source term is smaller than the radiologic source term because some or most of the radionuclide residual cannot be transported by groundwater. The radiologic source term has been determined for each of the underground nuclear tests fired at the NTS; however, the hydrologic source term has been estimated from measurements at only a few sites.

  2. Accident source terms for boiling water reactors with high burnup cores.

    SciTech Connect

    Gauntt, Randall O.; Powers, Dana Auburn; Leonard, Mark Thomas

    2007-11-01

    The primary objective of this report is to provide the technical basis for development of recommendations for updates to the NUREG-1465 Source Term for BWRs that will extend its applicability to accidents involving high burnup (HBU) cores. However, a secondary objective is to re-examine the fundamental characteristics of the prescription for fission product release to containment described by NUREG-1465. This secondary objective is motivated by an interest to understand the extent to which research into the release and behaviors of radionuclides under accident conditions has altered best-estimate calculations of the integral response of BWRs to severe core damage sequences and the resulting radiological source terms to containment. This report, therefore, documents specific results of fission product source term analyses that will form the basis for the HBU supplement to NUREG-1465. However, commentary is also provided on observed differences between the composite results of the source term calculations performed here and those reflected NUREG-1465 itself.

  3. Source term evaluation for combustion modeling

    NASA Technical Reports Server (NTRS)

    Sussman, Myles A.

    1993-01-01

    A modification is developed for application to the source terms used in combustion modeling. The modification accounts for the error of the finite difference scheme in regions where chain-branching chemical reactions produce exponential growth of species densities. The modification is first applied to a one-dimensional scalar model problem. It is then generalized to multiple chemical species, and used in quasi-one-dimensional computations of shock-induced combustion in a channel. Grid refinement studies demonstrate the improved accuracy of the method using this modification. The algorithm is applied in two spatial dimensions and used in simulations of steady and unsteady shock-induced combustion. Comparisons with ballistic range experiments give confidence in the numerical technique and the 9-species hydrogen-air chemistry model.

  4. TRIGA MARK-II source term

    NASA Astrophysics Data System (ADS)

    Usang, M. D.; Hamzah, N. S.; J. B., Abi M.; M. Z., M. Rawi; Abu, M. P.

    2014-02-01

    ORIGEN 2.2 are employed to obtain data regarding γ source term and the radio-activity of irradiated TRIGA fuel. The fuel composition are specified in grams for use as input data. Three types of fuel are irradiated in the reactor, each differs from the other in terms of the amount of Uranium compared to the total weight. Each fuel are irradiated for 365 days with 50 days time step. We obtain results on the total radioactivity of the fuel, the composition of activated materials, composition of fission products and the photon spectrum of the burned fuel. We investigate the differences of results using BWR and PWR library for ORIGEN. Finally, we compare the composition of major nuclides after 1 year irradiation of both ORIGEN library with results from WIMS. We found only minor disagreements between the yields of PWR and BWR libraries. In comparison with WIMS, the errors are a little bit more pronounced. To overcome this errors, the irradiation power used in ORIGEN could be increased a little, so that the differences in the yield of ORIGEN and WIMS could be reduced. A more permanent solution is to use a different code altogether to simulate burnup such as DRAGON and ORIGEN-S. The result of this study are essential for the design of radiation shielding from the fuel.

  5. TRIGA MARK-II source term

    SciTech Connect

    Usang, M. D. Hamzah, N. S. Abi, M. J. B. Rawi, M. Z. M. Rawi Abu, M. P.

    2014-02-12

    ORIGEN 2.2 are employed to obtain data regarding γ source term and the radio-activity of irradiated TRIGA fuel. The fuel composition are specified in grams for use as input data. Three types of fuel are irradiated in the reactor, each differs from the other in terms of the amount of Uranium compared to the total weight. Each fuel are irradiated for 365 days with 50 days time step. We obtain results on the total radioactivity of the fuel, the composition of activated materials, composition of fission products and the photon spectrum of the burned fuel. We investigate the differences of results using BWR and PWR library for ORIGEN. Finally, we compare the composition of major nuclides after 1 year irradiation of both ORIGEN library with results from WIMS. We found only minor disagreements between the yields of PWR and BWR libraries. In comparison with WIMS, the errors are a little bit more pronounced. To overcome this errors, the irradiation power used in ORIGEN could be increased a little, so that the differences in the yield of ORIGEN and WIMS could be reduced. A more permanent solution is to use a different code altogether to simulate burnup such as DRAGON and ORIGEN-S. The result of this study are essential for the design of radiation shielding from the fuel.

  6. Analysis of containment performance and radiological consequences under severe accident conditions for the Advanced Neutron Source Reactor at the Oak Ridge National Laboratory

    SciTech Connect

    Kim, S.H.; Taleyarkhan, R.P.

    1994-01-01

    A severe accident study was conducted to evaluate conservatively scoped source terms and radiological consequences to support the Advanced Neutron Source (ANS) Conceptual Safety Analysis Report (CSAR). Three different types of severe accident scenarios were postulated with a view of evaluating conservatively scoped source terms. The first scenario evaluates maximum possible steaming loads and associated radionuclide transport, whereas the next scenario is geared towards evaluating conservative containment loads from releases of radionuclide vapors and aerosols with associated generation of combustible gases. The third scenario follows the prescriptions given by the 10 CFR 100 guidelines. It was included in the CSAR for demonstrating site-suitability characteristics of the ANS. Various containment configurations are considered for the study of thermal-hydraulic and radiological behaviors of the ANS containment. Severe accident mitigative design features such as the use of rupture disks were accounted for. This report describes the postulated severe accident scenarios, methodology for analysis, modeling assumptions, modeling of several severe accident phenomena, and evaluation of the resulting source term and radiological consequences.

  7. 10 CFR 50.67 - Accident source term.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Accident source term. 50.67 Section 50.67 Energy NUCLEAR... Conditions of Licenses and Construction Permits § 50.67 Accident source term. (a) Applicability. The... to January 10, 1997, who seek to revise the current accident source term used in their design...

  8. 10 CFR 50.67 - Accident source term.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Accident source term. 50.67 Section 50.67 Energy NUCLEAR... Conditions of Licenses and Construction Permits § 50.67 Accident source term. (a) Applicability. The... to January 10, 1997, who seek to revise the current accident source term used in their design...

  9. Long-term source monitoring with BATSE

    NASA Technical Reports Server (NTRS)

    Wilson, R. B.; Harmon, B. A.; Finger, M. H.; Fishman, G. J.; Meegan, C. A.; Paciesas, W. S.

    1992-01-01

    The uncollimated Burst and Transient Source Experiment (BATSE) large area detectors (LADs) are well suited to nearly continuous monitoring of the stronger hard x-ray sources, and time series analysis for pulsars. An overview of the analysis techniques presently being applied to the data are discussed, including representative observations of the Crab Nebula, Crab pulsar, and summaries of the sources detected to data. Results of a search for variability in the Crab Pulsar pulse profile are presented.

  10. Radiation protection in pediatric radiology

    SciTech Connect

    Not Available

    1981-01-01

    The purpose of this report is to make available a source of practical information regarding the manner in which radiologic examinations in children should be conducted to reduce the radiation dose to these patients and those responsible for thier care. The report is mainly for the use of pediatricians, radiologists, radiologic technicians, and other personnel who order or use radiological methods in examining children, Appendices contain methods for estimating doses to various organs, and doses from various examinations in pediatric radiology. The Council has adopted some units of the SI system of nomenclature. A glossary of terms is included. (KRM)

  11. Improved radiological/nuclear source localization in variable NORM background: An MLEM approach with segmentation data

    NASA Astrophysics Data System (ADS)

    Penny, Robert D.; Crowley, Tanya M.; Gardner, Barbara M.; Mandell, Myron J.; Guo, Yanlin; Haas, Eric B.; Knize, Duane J.; Kuharski, Robert A.; Ranta, Dale; Shyffer, Ryan; Labov, Simon; Nelson, Karl; Seilhan, Brandon; Valentine, John D.

    2015-06-01

    A novel approach and algorithm have been developed to rapidly detect and localize both moving and static radiological/nuclear (R/N) sources from an airborne platform. Current aerial systems with radiological sensors are limited in their ability to compensate for variable naturally occurring radioactive material (NORM) background. The proposed approach suppresses the effects of NORM background by incorporating additional information to segment the survey area into regions over which the background is likely to be uniform. The method produces pixelated Source Activity Maps (SAMs) of both target and background radionuclide activity over the survey area. The task of producing the SAMs requires (1) the development of a forward model which describes the transformation of radionuclide activity to detector measurements and (2) the solution of the associated inverse problem. The inverse problem is ill-posed as there are typically fewer measurements than unknowns. In addition the measurements are subject to Poisson statistical noise. The Maximum-Likelihood Expectation-Maximization (MLEM) algorithm is used to solve the inverse problem as it is well suited for under-determined problems corrupted by Poisson noise. A priori terrain information is incorporated to segment the reconstruction space into regions within which we constrain NORM background activity to be uniform. Descriptions of the algorithm and examples of performance with and without segmentation on simulated data are presented.

  12. Phase 1 immobilized low-activity waste operational source term

    SciTech Connect

    Burbank, D.A.

    1998-03-06

    This report presents an engineering analysis of the Phase 1 privatization feeds to establish an operational source term for storage and disposal of immobilized low-activity waste packages at the Hanford Site. The source term information is needed to establish a preliminary estimate of the numbers of remote-handled and contact-handled waste packages. A discussion of the uncertainties and their impact on the source term and waste package distribution is also presented. It should be noted that this study is concerned with operational impacts only. Source terms used for accident scenarios would differ due to alpha and beta radiation which were not significant in this study.

  13. Justification Of The Use Of Boreholes For Disposal Of Sealed Radiological Sources

    SciTech Connect

    Zarling, John; Johnson, Peter

    2008-01-01

    Soon there will be only 14 states in two compacts that are able to dispose of Low Level Waste (LLW): the Northwest and Rocky Mountain compact with disposal options in Richland, Washington, and the Atlantic compact with disposal options in Barnwell, South Carolina. How do states not in one of the two compacts dispose of their LLW? The Off-Site Source Recovery Project can take possession and dispose of some of the unwanted transuranic sources at the Waste Isolation Pilot Plant (WIPP). However, there will be no path forward for states outside of the two compacts for disposal of their non-transuranic LLW. A solution that has been much discussed, debated and researched, but has not been put into wide scale practice, is the borehole disposal concept. It is the author's position that companies that drill and explore for oil have been disposing of sources in borehole-like structures for years. It should be noted that these companies are not purposely disposing of these sources, but the sources are irretrievable and must be abandoned. Additionally, there are Nuclear Regulatory Commission (NRC) regulations that must be followed to seal the well that contains the lost and abandoned source. According to the NRC Event Notification Reports database, there were a minimum of 29 reports of lost and abandoned sources in oil wells between December 1999 and October 2006. The sources were lost at depths between 2,018-18,887 feet, or 600-5,750 meters. The companies that are performing explorations with the aid of sealed radiological sources must follow regulation 10 CFR Part 39. Subsection 15 outlines the procedures that must be followed if sources are determined to be irretrievable and abandoned in place. If the NRC allows and has regulations in place for oil companies, why can't states and/or companies be allowed to dispose of LLW in a similar fashion?

  14. Examining the importance of the particle size effect in inhalation dose assessment for short-term radiological events.

    PubMed

    Srimok, Boonchawee; Yim, Man-Sung

    2011-11-01

    In this research work, the question of how important the particle size effect is in assessing radiological impact from a short-term radiological dispersal device incident is examined. A computer model, called puff particle size-dependent inhalation dose assessment (PIDA), was developed to support the task. The PIDA code is composed of submodels for atmospheric transport, dry deposition, resuspension, human exposure and dose analysis, with the particle size effect explicitly described in all of the submodels. The time-dependent nature of contaminant transport in the atmosphere during a short-term radiological incident was described by using a three-dimensional dispersion and one-dimensional advection Gaussian puff model. The results from the PIDA code were found to be in reasonable agreement with the experimental data from the Prairie Grass Project under various stability conditions and also with the calculation results from the CALPUFF code. The use of the PIDA code to examine the particle size effect in a short-term radiological incident showed that the particle size is one of the key parameters that contribute to the uncertainty of the estimated inhalation dose. The results also indicated that ignoring the particle size effect typically results in a conservative estimate of inhalation dose. In this regard, the use of an appropriately selected fixed value for particle size could be acceptable for a conservative estimate. PMID:21156784

  15. Clinical and Radiological Long-Term Follow-up After Embolization of Pulmonary Arteriovenous Malformations

    SciTech Connect

    Andersen, Poul Erik Kjeldsen, Anette D.

    2006-02-15

    The purpose was to evaluate the clinical and radiological long-term results of embolization of pulmonary arteriovenous malformations (PAVMs) and to assess the quality of life after treatment. A clinical follow-up was undertaken after 67 months (mean) in 35 consecutive patients with 106 PAVMs. Outcome parameters at follow-up were PaO{sub 2} and patients' satisfaction. During follow-up, the patients had a clinical examination, measurement of arterial blood gases, chest X-ray, and contrast echocardiography performed and were asked to fill in a questionnaire exploring experience of the treatment and subjective effect of treatment on physical and social functioning. A significant rise in oxygenation of the blood after embolization was measured. In 77% of the patients symptoms improved, and 71% felt better performance. In eight patients, one of the PAVMs was found insufficiently embolized or recanalized at follow-up angiography and therefore were re-embolized. Endovascular embolization for PAVMs is effective. Clinical parameters and quality of life improved significantly. Regular clinical controls after therapy are necessary to discover insufficiently embolized, recanalized or new PAVMs.

  16. Optimum target source term estimation for high energy electron accelerators

    NASA Astrophysics Data System (ADS)

    Nayak, M. K.; Sahu, T. K.; Nair, Haridas G.; Nandedkar, R. V.; Bandyopadhyay, Tapas; Tripathi, R. M.; Hannurkar, P. R.

    2016-05-01

    Optimum target for bremsstrahlung emission is defined as the thickness of the target material, which produces maximum bremsstrahlung yield, on interaction of electron with the target. The bremsstrahlung dose rate per unit electron beam power at a distance of 1 m from the target material gives the optimum target source term. In the present work, simulations were performed for three different electron energies, 450, 1000 and 2500 MeV using EGSnrc Monte-Carlo code to determine the optimum thickness. An empirical relation for optimum target as a function of electron energy and atomic number of the target materials is found out from results. Using the simulated optimum target thickness, experiments are conducted to determine the optimum target source term. For the experimental determination, two available electron energies, 450 MeV and 550 MeV from booster synchrotron of Indus facility is used. The optimum target source term for these two energies are also simulated. The experimental and simulated source term are found to be in very good agreement within ±3%. Based on the agreement of the simulated source term with the experimental source term at 450 MeV and 550 MeV, the same simulation methodology is used to simulate optimum target source term up to 2500 MeV. The paper describes the simulations and experiments carried out on optimum target bremsstrahlung source term and the results obtained.

  17. Adaptively Reevaluated Bayesian Localization (ARBL): A novel technique for radiological source localization

    NASA Astrophysics Data System (ADS)

    Miller, Erin A.; Robinson, Sean M.; Anderson, Kevin K.; McCall, Jonathon D.; Prinke, Amanda M.; Webster, Jennifer B.; Seifert, Carolyn E.

    2015-06-01

    We present a novel technique for the localization of radiological sources in urban or rural environments from an aerial platform. The technique is based on a Bayesian approach to localization, in which measured count rates in a time series are compared with predicted count rates from a series of pre-calculated test sources to define likelihood. This technique is expanded by using a localized treatment with a limited field of view (FOV), coupled with a likelihood ratio reevaluation, allowing for real-time computation on commodity hardware for arbitrarily complex detector models and terrain. In particular, detectors with inherent asymmetry of response (such as those employing internal collimation or self-shielding for enhanced directional awareness) are leveraged by this approach to provide improved localization. Results from the localization technique are shown for simulated flight data using monolithic as well as directionally-aware detector models, and the capability of the methodology to locate radioisotopes is estimated for several test cases. This localization technique is shown to facilitate urban search by allowing quick and adaptive estimates of source location, in many cases from a single flyover near a source. In particular, this method represents a significant advancement from earlier methods like full-field Bayesian likelihood, which is not generally fast enough to allow for broad-field search in real time, and highest-net-counts estimation, which has a localization error that depends strongly on flight path and cannot generally operate without exhaustive search.

  18. Adaptively Reevaluated Bayesian Localization (ARBL). A Novel Technique for Radiological Source Localization

    SciTech Connect

    Miller, Erin A.; Robinson, Sean M.; Anderson, Kevin K.; McCall, Jonathon D.; Prinke, Amanda M.; Webster, Jennifer B.; Seifert, Carolyn E.

    2015-01-19

    Here we present a novel technique for the localization of radiological sources in urban or rural environments from an aerial platform. The technique is based on a Bayesian approach to localization, in which measured count rates in a time series are compared with predicted count rates from a series of pre-calculated test sources to define likelihood. Furthermore, this technique is expanded by using a localized treatment with a limited field of view (FOV), coupled with a likelihood ratio reevaluation, allowing for real-time computation on commodity hardware for arbitrarily complex detector models and terrain. In particular, detectors with inherent asymmetry of response (such as those employing internal collimation or self-shielding for enhanced directional awareness) are leveraged by this approach to provide improved localization. Our results from the localization technique are shown for simulated flight data using monolithic as well as directionally-aware detector models, and the capability of the methodology to locate radioisotopes is estimated for several test cases. This localization technique is shown to facilitate urban search by allowing quick and adaptive estimates of source location, in many cases from a single flyover near a source. In particular, this method represents a significant advancement from earlier methods like full-field Bayesian likelihood, which is not generally fast enough to allow for broad-field search in real time, and highest-net-counts estimation, which has a localization error that depends strongly on flight path and cannot generally operate without exhaustive search

  19. The LINAC Coherent Light Source and Radiological Issues During the Commissioning

    SciTech Connect

    Mao, X.S.; Leitner, M.Santana; Vollaire, J.; /SLAC

    2010-08-26

    The Linac Coherent Light Source (LCLS) at SLAC National Accelerator Laboratory is the world's first X-ray free electron laser (XFEL). Pulses of x-ray laser light from LCLS will be many orders of magnitude brighter and several orders of magnitude shorter than what can be produced by other x-ray sources available in the world. These characteristics will enable frontier new science in many areas. This paper describes the LCLS beam parameters and lay-out. The general radiological issues during commissioning are presented, such as radiation dose rates and integrated doses outside the enclosure. Also, specific radiological issues related to X-ray free electron lasers are discussed. XFEL with high peak power will burn through high-Z materials. The X-ray beam needs to be blocked by stoppers when the downstream areas are occupied. LCLS stoppers feature a piece of boron carbide (B{sub 4}C), 10 mm thick. B{sub 4}C is one of the best materials since it has a low absorption coefficient for X-rays and a high melting temperature. Theoretical calculations indicate that the unfocused fluence of the LCLS XFEL beam should be about one order of magnitude below the damage threshold for bulk B{sub 4}C, for 830 eV FEL radiation. However, these calculations have not been tested experimentally and cannot be validated until LCLS begins providing 830 eV XFEL pulses. This paper describes the test plan for using the initial LCLS radiation to evaluate the survivability of B{sub 4}C and reports the preliminary results. Another major issue for LCLS is the potential radiation damage to the LCLS undulator magnets during operation. TLD dosimeters were installed along the LCLS undulators for each period of two or three weeks. This paper reports the integrated doses along the undulators with and without XFEL generation.

  20. Source term calculations for assessing radiation dose to equipment

    SciTech Connect

    Denning, R.S.; Freeman-Kelly, R.; Cybulskis, P.; Curtis, L.A.

    1989-07-01

    This study examines results of analyses performed with the Source Term Code Package to develop updated source terms using NUREG-0956 methods. The updated source terms are to be used to assess the adequacy of current regulatory source terms used as the basis for equipment qualification. Time-dependent locational distributions of radionuclides within a containment following a severe accident have been developed. The Surry reactor has been selected in this study as representative of PWR containment designs. Similarly, the Peach Bottom reactor has been used to examine radionuclide distributions in boiling water reactors. The time-dependent inventory of each key radionuclide is provided in terms of its activity in curies. The data are to be used by Sandia National Laboratories to perform shielding analyses to estimate radiation dose to equipment in each containment design. See NUREG/CR-5175, Beta and Gamma Dose Calculations for PWR and BWR Containments.'' 6 refs., 11 tabs.

  1. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    SciTech Connect

    Pete Lowry

    2012-01-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  2. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    SciTech Connect

    Pete Lowry

    2012-10-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  3. Scoping Analysis of Source Term and Functional Containment Attenuation Factors

    SciTech Connect

    Pete Lowry

    2012-02-01

    In order to meet future regulatory requirements, the Next Generation Nuclear Plant (NGNP) Project must fully establish and validate the mechanistic modular high temperature gas-cooled reactor (HTGR) source term. This is not possible at this stage in the project, as significant uncertainties in the final design remain unresolved. In the interim, however, there is a need to establish an approximate characterization of the source term. The NGNP team developed a simplified parametric model to establish mechanistic source term estimates for a set of proposed HTGR configurations.

  4. Source Term Model for an Array of Vortex Generator Vanes

    NASA Technical Reports Server (NTRS)

    Buning, P. G. (Technical Monitor); Waithe, Kenrick A.

    2003-01-01

    A source term model was developed for numerical simulations of an array of vortex generators. The source term models the side force created by a vortex generator being modeled. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on a local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low-profile vortex generator vane, which is only a fraction of the boundary layer thickness, over a flat plate. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data.

  5. Revised accident source terms for light-water reactors

    SciTech Connect

    Soffer, L.

    1995-02-01

    This paper presents revised accident source terms for light-water reactors incorporating the severe accident research insights gained in this area over the last 15 years. Current LWR reactor accident source terms used for licensing date from 1962 and are contained in Regulatory Guides 1.3 and 1.4. These specify that 100% of the core inventory of noble gases and 25% of the iodine fission products are assumed to be instantaneously available for release from the containment. The chemical form of the iodine fission products is also assumed to be predominantly elemental iodine. These assumptions have strongly affected present nuclear air cleaning requirements by emphasizing rapid actuation of spray systems and filtration systems optimized to retain elemental iodine. A proposed revision of reactor accident source terms and some im implications for nuclear air cleaning requirements was presented at the 22nd DOE/NRC Nuclear Air Cleaning Conference. A draft report was issued by the NRC for comment in July 1992. Extensive comments were received, with the most significant comments involving (a) release fractions for both volatile and non-volatile species in the early in-vessel release phase, (b) gap release fractions of the noble gases, iodine and cesium, and (c) the timing and duration for the release phases. The final source term report is expected to be issued in late 1994. Although the revised source terms are intended primarily for future plants, current nuclear power plants may request use of revised accident source term insights as well in licensing. This paper emphasizes additional information obtained since the 22nd Conference, including studies on fission product removal mechanisms, results obtained from improved severe accident code calculations and resolution of major comments, and their impact upon the revised accident source terms. Revised accident source terms for both BWRS and PWRS are presented.

  6. Progress in Development of Dense Plasma Focus Pinch for AmBe Radiological Source Replacement

    NASA Astrophysics Data System (ADS)

    Falabella, Steve; Povilus, Alex; Schmidt, Andrea; Ellsworth, Jennifer; Link, Anthony; Sears, Jason; Higginson, Drew; Jiang, Sheng

    2015-11-01

    A dense plasma focus (DPF) is a compact plasma gun accelerator that can produce intense, high energy ion beams (multiple MeV). These ion beams could be used to replace radiological sources for a variety of applications. Using a 2kJ DPF with a helium gas fill, alpha particles are accelerated into a beryllium target in order to generate a neutron spectrum similar to an AmBe source. We report on initial observations of neutron yields for this system and efforts to optimize and improve repeatability of pinch performance. In particular, incorporating results from newly-developed kinetic LSP simulations, we demonstrated higher neutron yields by adjusting the geometry of the anode electrode. In addition, we present preliminary measurements for energy distributions of ions accelerated by the pinch. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work supported by US DOE/NA-22 Office of Non-proliferation Research and Development.

  7. Tympanomastoid cholesterol granuloma: radiological and intraoperative findings of blood source connection.

    PubMed

    Iannella, Giannicola; Stasolla, Alessandro; Pasquariello, Benedetta; Re, Massimo; Magliulo, Giuseppe

    2016-09-01

    The hypothesis that the close contiguity between the cholesterol granulomas and some rich blood sources provided the trigger to the aggressive nature of tympanomastoid cholesterol granulomas has been recently reported. To corroborate this new etiopathogenetic theory we retrospectively reviewed a series of 14 patients with primary middle ear and mastoid cholesterol granulomas and investigated the temporal bone marrow invasion and its hematopoietic potentialities and a possible cholesterol granulomas contiguity with relevant vascular structures such as the carotid artery, sigmoid jugular system, mastoid or dural vein. Eight cases did not show radiological sign of bone marrow invasion or hematopoietic potentialities visible in MRI. Besides no intraoperative vascular connections that could explain an initial bleeding source were found. Cholesterol granulomas bone marrow invasion was present in six patients. A bone marrow hematopoietic potentiality was showed in four of these patients, whereas, an evident anatomical contiguity of the cholesterol granuloma with some important temporal bone vascular structures was visible in five cases. Analysis of cardiovascular risk factors showed that four patients presented one or more of the risk factors analysed. PMID:26521188

  8. Radiological Assessment for the Vance Road Facility Source Vault, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee

    SciTech Connect

    J. R. Morton

    2000-09-01

    From the 1950s, the Vance Road laboratories had been used for a broad range of nuclear medicine research involving numerous radionuclides. These radionuclides were stored in the a source vault located on the first floor of the facility. The Environmental Survey and Site Assessment Program (ESSAP) of ORISE performed a radiological assessment survey of the source vault after it had been remediated and in preparation for converting the area to office space.

  9. Radiological Threat Reduction (RTR) program : implementing physical security to protect large radioactive sources worldwide.

    SciTech Connect

    Lowe, Daniel L.

    2004-11-01

    The U.S. Department of Energy's Radiological Threat Reduction (RTR) Program strives to reduce the threat of a Radiological Dispersion Device (RDD) incident that could affect U.S. interests worldwide. Sandia National Laboratories supports the RTR program on many different levels. Sandia works directly with DOE to develop strategies, including the selection of countries to receive support and the identification of radioactive materials to be protected. Sandia also works with DOE in the development of guidelines and in training DOE project managers in physical protection principles. Other support to DOE includes performing rapid assessments and providing guidance for establishing foreign regulatory and knowledge infrastructure. Sandia works directly with foreign governments to establish cooperative agreements necessary to implement the RTR Program efforts to protect radioactive sources. Once necessary agreements are in place, Sandia works with in-country organizations to implement various security related initiatives, such as installing security systems and searching for (and securing) orphaned radioactive sources. The radioactive materials of interest to the RTR program include Cobalt 60, Cesium 137, Strontium 90, Iridium 192, Radium 226, Plutonium 238, Americium 241, Californium 252, and Others. Security systems are implemented using a standardized approach that provides consistency through out the RTR program efforts at Sandia. The approach incorporates a series of major tasks that overlap in order to provide continuity. The major task sequence is to: Establish in-country contacts - integrators, Obtain material characterizations, Perform site assessments and vulnerability assessments, Develop upgrade plans, Procure and install equipment, Conduct acceptance testing and performance testing, Develop procedures, and Conduct training. Other tasks are incorporated as appropriate and commonly include such as support of reconfiguring infrastructure, and developing security

  10. Selection of models to calculate the LLW source term

    SciTech Connect

    Sullivan, T.M. )

    1991-10-01

    Performance assessment of a LLW disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). In turn, many of these physical processes are influenced by the design of the disposal facility (e.g., infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This document provides a brief overview of disposal practices and reviews existing source term models as background for selecting appropriate models for estimating the source term. The selection rationale and the mathematical details of the models are presented. Finally, guidance is presented for combining the inventory data with appropriate mechanisms describing release from the disposal facility. 44 refs., 6 figs., 1 tab.

  11. Management of Ultimate Risk of Nuclear Power Plants by Source Terms - Lessons Learned from the Chernobyl Accident

    SciTech Connect

    Genn Saji

    2006-07-01

    The term 'ultimate risk' is used here to describe the probabilities and radiological consequences that should be incorporated in siting, containment design and accident management of nuclear power plants for hypothetical accidents. It is closely related with the source terms specified in siting criteria which assures an adequate separation of radioactive inventories of the plants from the public, in the event of a hypothetical and severe accident situation. The author would like to point out that current source terms which are based on the information from the Windscale accident (1957) through TID-14844 are very outdated and do not incorporate lessons learned from either the Three Miles Island (TMI, 1979) nor Chernobyl accident (1986), two of the most severe accidents ever experienced. As a result of the observations of benign radionuclides released at TMI, the technical community in the US felt that a more realistic evaluation of severe reactor accident source terms was necessary. In this background, the 'source term research project' was organized in 1984 to respond to these challenges. Unfortunately, soon after the time of the final report from this project was released, the Chernobyl accident occurred. Due to the enormous consequences induced by then accident, the one time optimistic perspectives in establishing a more realistic source term were completely shattered. The Chernobyl accident, with its human death toll and dispersion of a large part of the fission fragments inventories into the environment, created a significant degradation in the public's acceptance of nuclear energy throughout the world. In spite of this, nuclear communities have been prudent in responding to the public's anxiety towards the ultimate safety of nuclear plants, since there still remained many unknown points revolving around the mechanism of the Chernobyl accident. In order to resolve some of these mysteries, the author has performed a scoping study of the dispersion and deposition

  12. Flowsheets and source terms for radioactive waste projections

    SciTech Connect

    Forsberg, C.W.

    1985-03-01

    Flowsheets and source terms used to generate radioactive waste projections in the Integrated Data Base (IDB) Program are given. Volumes of each waste type generated per unit product throughput have been determined for the following facilities: uranium mining, UF/sub 6/ conversion, uranium enrichment, fuel fabrication, boiling-water reactors (BWRs), pressurized-water reactors (PWRs), and fuel reprocessing. Source terms for DOE/defense wastes have been developed. Expected wastes from typical decommissioning operations for each facility type have been determined. All wastes are also characterized by isotopic composition at time of generation and by general chemical composition. 70 references, 21 figures, 53 tables.

  13. Spallation Neutron Source Accident Terms for Environmental Impact Statement Input

    SciTech Connect

    Devore, J.R.; Harrington, R.M.

    1998-08-01

    This report is about accidents with the potential to release radioactive materials into the environment surrounding the Spallation Neutron Source (SNS). As shown in Chap. 2, the inventories of radioactivity at the SNS are dominated by the target facility. Source terms for a wide range of target facility accidents, from anticipated events to worst-case beyond-design-basis events, are provided in Chaps. 3 and 4. The most important criterion applied to these accident source terms is that they should not underestimate potential release. Therefore, conservative methodology was employed for the release estimates. Although the source terms are very conservative, excessive conservatism has been avoided by basing the releases on physical principles. Since it is envisioned that the SNS facility may eventually (after about 10 years) be expanded and modified to support a 4-MW proton beam operational capability, the source terms estimated in this report are applicable to a 4-MW operating proton beam power unless otherwise specified. This is bounding with regard to the 1-MW facility that will be built and operated initially. See further discussion below in Sect. 1.2.

  14. Low-level waste disposal performance assessments - Total source-term analysis

    SciTech Connect

    Wilhite, E.L.

    1995-12-31

    Disposal of low-level radioactive waste at Department of Energy (DOE) facilities is regulated by DOE. DOE Order 5820.2A establishes policies, guidelines, and minimum requirements for managing radioactive waste. Requirements for disposal of low-level waste emplaced after September 1988 include providing reasonable assurance of meeting stated performance objectives by completing a radiological performance assessment. Recently, the Defense Nuclear Facilities Safety Board issued Recommendation 94-2, {open_quotes}Conformance with Safety Standards at Department of Energy Low-Level Nuclear Waste and Disposal Sites.{close_quotes} One of the elements of the recommendation is that low-level waste performance assessments do not include the entire source term because low-level waste emplaced prior to September 1988, as well as other DOE sources of radioactivity in the ground, are excluded. DOE has developed and issued guidance for preliminary assessments of the impact of including the total source term in performance assessments. This paper will present issues resulting from the inclusion of all DOE sources of radioactivity in performance assessments of low-level waste disposal facilities.

  15. Common Calibration Source for Monitoring Long-term Ozone Trends

    NASA Technical Reports Server (NTRS)

    Kowalewski, Matthew

    2004-01-01

    Accurate long-term satellite measurements are crucial for monitoring the recovery of the ozone layer. The slow pace of the recovery and limited lifetimes of satellite monitoring instruments demands that datasets from multiple observation systems be combined to provide the long-term accuracy needed. A fundamental component of accurately monitoring long-term trends is the calibration of these various instruments. NASA s Radiometric Calibration and Development Facility at the Goddard Space Flight Center has provided resources to minimize calibration biases between multiple instruments through the use of a common calibration source and standardized procedures traceable to national standards. The Facility s 50 cm barium sulfate integrating sphere has been used as a common calibration source for both US and international satellite instruments, including the Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet 2 (SBUV/2) instruments, Shuttle SBUV (SSBUV), Ozone Mapping Instrument (OMI), Global Ozone Monitoring Experiment (GOME) (ESA), Scanning Imaging SpectroMeter for Atmospheric ChartographY (SCIAMACHY) (ESA), and others. We will discuss the advantages of using a common calibration source and its effects on long-term ozone data sets. In addition, sphere calibration results from various instruments will be presented to demonstrate the accuracy of the long-term characterization of the source itself.

  16. Optimization approaches to decision making on long-term cleanup and site restoration following a nuclear or radiological terrosim incident.

    SciTech Connect

    Chen, S. Y.; Tenforde, T. S.; Environmental Science Division; National Council on Radiation Protection and Measurements

    2010-01-01

    Emergency planning activities have historically focused on the early phase of an event, especially issues associated with triaging in the initial response such as rescuing survivors. The most difficult task following an event may be the eventual recovery of society's most affected areas; the government must spend a large amount of money and effort to cope with the long-term site cleanup and restoration issues. In particular, the underlying principles and implementation guidelines for conducting the recovery effort have not been well developed. Following publication of the National Response Framework by the U.S. Department of Homeland Security, some major responsibilities have been identified and defined. For example, DHS recently published Protective Action Guides as planning guidance for health protection and recovery following incidents involving Radiological Dispersal Devices or Improvised Nuclear Devices. For the first time, the guidance addresses long-term recovery issues associated with radiological events, for which an 'optimization' process is prescribed to address the multifaceted, long-term recovery effort. This article analyzes this particular subject more deeply and evaluates the critical need for further development.

  17. CHALLENGES IN SOURCE TERM MODELING OF DECONTAMINATION AND DECOMMISSIONING WASTES.

    SciTech Connect

    SULLIVAN, T.M.

    2006-08-01

    Development of real-time predictive modeling to identify the dispersion and/or source(s) of airborne weapons of mass destruction including chemical, biological, radiological, and nuclear material in urban environments is needed to improve response to potential releases of these materials via either terrorist or accidental means. These models will also prove useful in defining airborne pollution dispersion in urban environments for pollution management/abatement programs. Predicting gas flow in an urban setting on a scale of less than a few kilometers is a complicated and challenging task due to the irregular flow paths that occur along streets and alleys and around buildings of different sizes and shapes, i.e., ''urban canyons''. In addition, air exchange between the outside and buildings and subway areas further complicate the situation. Transport models that are used to predict dispersion of WMD/CBRN materials or to back track the source of the release require high-density data and need defensible parameterizations of urban processes. Errors in the data or any of the parameter inputs or assumptions will lead to misidentification of the airborne spread or source release location(s). The need for these models to provide output in a real-time fashion if they are to be useful for emergency response provides another challenge. To improve the ability of New York City's (NYC's) emergency management teams and first response personnel to protect the public during releases of hazardous materials, the New York City Urban Dispersion Program (UDP) has been initiated. This is a four year research program being conducted from 2004 through 2007. This paper will discuss ground level and subway Perfluorocarbon tracer (PFT) release studies conducted in New York City. The studies released multiple tracers to study ground level and vertical transport of contaminants. This paper will discuss the results from these tests and how these results can be used for improving transport models

  18. Improved source term estimation using blind outlier detection

    NASA Astrophysics Data System (ADS)

    Martinez-Camara, Marta; Bejar Haro, Benjamin; Vetterli, Martin; Stohl, Andreas

    2014-05-01

    Emissions of substances into the atmosphere are produced in situations such as volcano eruptions, nuclear accidents or pollutant releases. It is necessary to know the source term - how the magnitude of these emissions changes with time - in order to predict the consequences of the emissions, such as high radioactivity levels in a populated area or high concentration of volcanic ash in an aircraft flight corridor. However, in general, we know neither how much material was released in total, nor the relative variation of emission strength with time. Hence, estimating the source term is a crucial task. Estimating the source term generally involves solving an ill-posed linear inverse problem using datasets of sensor measurements. Several so-called inversion methods have been developed for this task. Unfortunately, objective quantitative evaluation of the performance of inversion methods is difficult due to the fact that the ground truth is unknown for practically all the available measurement datasets. In this work we use the European Tracer Experiment (ETEX) - a rare example of an experiment where the ground truth is available - to develop and to test new source estimation algorithms. Knowledge of the ground truth grants us access to the additive error term. We show that the distribution of this error is heavy-tailed, which means that some measurements are outliers. We also show that precisely these outliers severely degrade the performance of traditional inversion methods. Therefore, we develop blind outlier detection algorithms specifically suited to the source estimation problem. Then, we propose new inversion methods that combine traditional regularization techniques with blind outlier detection. Such hybrid methods reduce the error of reconstruction of the source term up to 45% with respect to previously proposed methods.

  19. Global Radiological Source Sorting, Tracking, and Monitoring Project: Phase I Final Report

    SciTech Connect

    Walker, Randy M; Hill, David E; Gorman, Bryan L

    2010-09-01

    As a proof of concept tested in an operational context, the Global Radiological Source Sorting, Tracking, and Monitoring (GRadSSTraM) Project successfully demonstrated that radio frequency identification (RFID) and Web 2.0* technologies can be deployed to track controlled shipments between the United States and the European Union. Between November 2009 and May 2010, a total of 19 shipments were successfully shipped from Oak Ridge National Laboratory (ORNL) by the U.S. Postal Service (USPS) and tracked to their delivery at England's National Physical Laboratory (NPL) by the United Kingdom Royal Mail. However, the project can only be viewed as a qualified success as notable shortcomings were observed. Although the origin and terminus of all RFID-enabled shipments were recorded and no shipments were lost, not all the waypoints between ORNL and NPL were incorporated into the pilot. Given limited resources, the project team was able to install RFID listeners/actuators at three waypoints between the two endpoints. Although it is likely that all shipments followed the same route between ORNL and NPL, it cannot be determined beyond question that all 19 shipments were routed on identical itineraries past the same three waypoints. The pilot also raises the distinct possibility that unattended RFID tracking alone, without positive confirmation that a tagged item has been properly recorded by an RFID reader, does not meet a rigorous standard for shipping controlled items. Indeed, the proof of concept test strongly suggests that a multifaceted approach to tracking may be called for, including tracking methods that are capable of reading and accepting multiple inputs for individual items [e.g., carrier-provided tracking numbers, Universal Product Codes (UPCs), and RFID tags]. For controlled items, another apparent requirement is a confirmation feature, human or otherwise, which can certify that an item's RFID tag, UPC, or tracking number has been recorded.

  20. Source Term Code Package: a user's guide (Mod 1)

    SciTech Connect

    Gieseke, J.A.; Cybulskis, P.; Jordan, H.; Lee, K.W.; Schumacher, P.M.; Curtis, L.A.; Wooton, R.O.; Quayle, S.F.; Kogan, V.

    1986-07-01

    As part of a major reassessment of the release of radioactive materials to the environment (source terms) in severe reactor accidents, a group of state-of-the-art computer codes was utilized to perform extensive analyses. A major product of this source term reassessment effort was a demonstrated methodology for analyzing specific accident situations to provide source term predictions. The computer codes forming this methodology have been upgraded and modified for release and further use. This system of codes has been named the Source Term Code Package (STCP) and is the subject of this user's guide. The guide is intended to provide an understanding of the STCP structure and to facilitate STCP use. The STCP was prepared for operation on a CDC system but is written in FORTRAN-77 to permit transportability. In the current version (Mod 1) of the STCP, the various calculational elements fall into four major categories represented by the codes MARCH3, TRAP-MELT3, VANESA, and NAUA/SPARC/ICEDF. The MARCH3 code is a combination of the MARCH2, CORSOR-M, and CORCON-Mod 2 codes. The TRAP-MELT3 code is a combination of the TRAP-MELT2.0 and MERGE codes.

  1. Disposal Unit Source Term (DUST) data input guide

    SciTech Connect

    Sullivan, T.M.

    1993-05-01

    Performance assessment of a low-level waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). The computer code DUST (Disposal Unit Source Term) has been developed to model these processes. This document presents the models used to calculate release from a disposal facility, verification of the model, and instructions on the use of the DUST code. In addition to DUST, a preprocessor, DUSTIN, which helps the code user create input decks for DUST and a post-processor, GRAFXT, which takes selected output files and plots them on the computer terminal have been written. Use of these codes is also described.

  2. BWR ASSEMBLY SOURCE TERMS FOR WASTE PACKAGE DESIGN

    SciTech Connect

    T.L. Lotz

    1997-02-15

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide boiling water reactor (BWR) assembly radiation source term data for use during Waste Package (WP) design. The BWR assembly radiation source terms are to be used for evaluation of radiolysis effects at the WP surface, and for personnel shielding requirements during assembly or WP handling operations. The objectives of this evaluation are to generate BWR assembly radiation source terms that bound selected groupings of BWR assemblies, with regard to assembly average burnup and cooling time, which comprise the anticipated MGDS BWR commercial spent nuclear fuel (SNF) waste stream. The source term data is to be provided in a form which can easily be utilized in subsequent shielding/radiation dose calculations. Since these calculations may also be used for Total System Performance Assessment (TSPA), with appropriate justification provided by TSPA, or radionuclide release rate analysis, the grams of each element and additional cooling times out to 25 years will also be calculated and the data included in the output files.

  3. DWPFASTXL: Defense Waste Processing Facility Algorithm for Source Terms for Excel

    SciTech Connect

    Toole, B.; Gough, S.T.

    1994-11-01

    Software & Copyright Submittal The tool used to analyze the progression of accidents in the DWPF is called an Accident Progression Event Tree (APET). The APET methodology groups analyzed progressions into a series of bins, based on similarities in their characteristics. DWPFASTXL is an Excel spreadsheet that can be used to calculate radiological source terms and consequences for these accident progression bins. This document presents the calculations used in version 2.0 of the DWPFASTXL spreadsheet. This revision of DWPFASTXL has been written to complete the debugging of version 1.0, and to reconfigure the spreadsheet to model the new bin attribute table developed for the latest revision of the DWPF safety analyses

  4. Bayesian Estimation of Prior Variance in Source Term Determination

    NASA Astrophysics Data System (ADS)

    Smidl, Vaclav; Hofman, Radek

    2015-04-01

    The problem of determination of source term of an atmospheric release is studied. We assume that the observations y are obtained as linear combination of the source term, x, and source-receptor sensitivities, which can be written in matrix notation as y = Mx with source receptor sensitivity matrix M. Direct estimation of the source term vector x is not possible since the system is often ill-conditioned. The solution is thus found by minimization of a cost function with regularization terms. A typical cost function is: C (x) = (y - M x)TR-1(y- M x) + αxTDT Dx, (1) where the first term minimizes the error of the measurements with covariance matrix R, and the second term is the regularization with weight α. Various types of regularization arise for different choices of matrix D. For example, Tikhonov regularization arises for D in the form of identity matrix, and smoothing regularization for D in the form of a tri-diagonal matrix (Laplacian operator). Typically, the form of matrix D is assumed to be known, and the weight α is optimized manually by a trial and error procedure. In this contribution, we use the probabilistic formulation of the problem, where term (αDTD)-1 is interpreted as a covariance matrix of the prior distribution of x. Following the Bayesian approach, we relax the assumption of known α and D and assume that these are unknown and estimated from the data. The general problem is not analytically tractable and approximate estimation techniques has to be used. We present Variational Bayesian solution of two special cases of the prior covariance matrix. First, the structure of D is assumed to be known and only the weight α is estimated. Application of the Variational Bayes method to this case yields an iterative estimation algorithm. In the first step, the usual optimization problem is solved for an estimate of α. In the next step, the value of α is re-estimated and the procedure returns to the first step. Positivity of the solution is guaranteed

  5. Analysis of source term modeling for low-level radioactive waste performance assessments

    SciTech Connect

    Icenhour, A.S.

    1995-03-01

    Site-specific radiological performance assessments are required for the disposal of low-level radioactive waste (LLW) at both commercial and US Department of Energy facilities. This work explores source term modeling of LLW disposal facilities by using two state-of-the-art computer codes, SOURCEI and SOURCE2. An overview of the performance assessment methodology is presented, and the basic processes modeled in the SOURCE1 and SOURCE2 codes are described. Comparisons are made between the two advective models for a variety of radionuclides, transport parameters, and waste-disposal technologies. These comparisons show that, in general, the zero-order model predicts undecayed cumulative fractions leached that are slightly greater than or equal to those of the first-order model. For long-lived radionuclides, results from the two models eventually reach the same value. By contrast, for short-lived radionuclides, the zero-order model predicts a slightly higher undecayed cumulative fraction leached than does the first-order model. A new methodology, based on sensitivity and uncertainty analyses, is developed for predicting intruder scenarios. This method is demonstrated for {sup 137}Cs in a tumulus-type disposal facility. The sensitivity and uncertainty analyses incorporate input-parameter uncertainty into the evaluation of a potential time of intrusion and the remaining radionuclide inventory. Finally, conclusions from this study are presented, and recommendations for continuing work are made.

  6. Phonatory sound sources in terms of Lagrangian Coherent Structures

    NASA Astrophysics Data System (ADS)

    McPhail, Michael; Krane, Michael

    2015-11-01

    Lagrangian Coherent Structures (LCS) are used to identify sound sources in phonation. Currently, it is difficult to causally relate changes in airflow topology from voice disorders to changes in voiced sound production. LCS reveals a flow's topology by decomposing the flow into regions of distinct dynamics. The aeroacoustic sources can be written in terms of the motion of these regions in terms of the motion of the boundaries of the distinct regions. Breaking down the flow into constituent parts shows how each distinct region contributes to sound production. This approach provides a framework to connect changes in anatomy from a voice disorder to measurable changes in the resulting sound. This approach is presented for simulations of some canonical cases of vortex sound generation, and a two-dimensional simulation of phonation. Acknowledge NIH grant 2R01 2R01DC005642.

  7. A nuclear source term analysis for spacecraft power systems

    SciTech Connect

    McCulloch, W.H.

    1998-12-01

    All US space missions involving on board nuclear material must be approved by the Office of the President. To be approved the mission and the hardware systems must undergo evaluations of the associated nuclear health and safety risk. One part of these evaluations is the characterization of the source terms, i.e., the estimate of the amount, physical form, and location of nuclear material, which might be released into the environment in the event of credible accidents. This paper presents a brief overview of the source term analysis by the Interagency Nuclear Safety Review Panel for the NASA Cassini Space Mission launched in October 1997. Included is a description of the Energy Interaction Model, an innovative approach to the analysis of potential releases from high velocity impacts resulting from launch aborts and reentries.

  8. Extent of Disc Degeneration after Single-Level Cervical Anterior Microforaminotomy Analyzed with Long-Term Radiological Data

    PubMed Central

    Han, Chul

    2014-01-01

    Objective To prove the extents and details of cervical degeneration after anterior microforaminotomy (AMF) with 6-years follow-up. Methods A retrospective study of 24 patients, underwent single-level AMF, was performed. Clinical and radiologic data were analyzed with office charts, questionaires, and picture achieving and communication system images. Results According to Odom's criteria, 91.6% achieved favorable outcome. The mean visual analog scale score was improved from 8.6 to 3, and the mean neck disability index was improved from 27.9 to 7.3 (p<0.01). Eighteen cases (75%) showed disc height (DH) decrease. The disc invasion was correlated with DH decrease (p<0.05). The disc height decrease correlated with static, dynamic changes of shell angle and spur formation (p<0.05). Any radiological parameters did not affect the clinical outcome. Conclusion AMF is an effective technique for treating unilateral cervical radiculopathy. It showed excellent surgical outcomes even in long-term follow-ups. However, a decrease in DH occurred in a considerable number of patients. Disc invasion during surgery may be the trigger of sequential degeneration. PMID:25368761

  9. Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron

    NASA Astrophysics Data System (ADS)

    Hojo, S.; Katagiri, K.; Nakao, M.; Sugiura, A.; Muramatsu, M.; Noda, A.; Okada, T.; Takahashi, Y.; Komiyama, A.; Honma, T.; Noda, K.

    2014-02-01

    The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C4+ ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8-10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 μA for proton and deuteron, 50 μA for C4+, for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source.

  10. Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron.

    PubMed

    Hojo, S; Katagiri, K; Nakao, M; Sugiura, A; Muramatsu, M; Noda, A; Okada, T; Takahashi, Y; Komiyama, A; Honma, T; Noda, K

    2014-02-01

    The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C(4+) ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8-10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 μA for proton and deuteron, 50 μA for C(4+), for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source. PMID:24593538

  11. Actinide Source Term Program, position paper. Revision 1

    SciTech Connect

    Novak, C.F.; Papenguth, H.W.; Crafts, C.C.; Dhooge, N.J.

    1994-11-15

    The Actinide Source Term represents the quantity of actinides that could be mobilized within WIPP brines and could migrate with the brines away from the disposal room vicinity. This document presents the various proposed methods for estimating this source term, with a particular focus on defining these methods and evaluating the defensibility of the models for mobile actinide concentrations. The conclusions reached in this document are: the 92 PA {open_quotes}expert panel{close_quotes} model for mobile actinide concentrations is not defensible; and, although it is extremely conservative, the {open_quotes}inventory limits{close_quotes} model is the only existing defensible model for the actinide source term. The model effort in progress, {open_quotes}chemical modeling of mobile actinide concentrations{close_quotes}, supported by a laboratory effort that is also in progress, is designed to provide a reasonable description of the system and be scientifically realistic and supplant the {open_quotes}Inventory limits{close_quotes} model.

  12. Analytical source term optimization for radioactive releases with approximate knowledge of nuclide ratios

    NASA Astrophysics Data System (ADS)

    Hofman, Radek; Seibert, Petra; Kovalets, Ivan; Andronopoulos, Spyros

    2015-04-01

    We are concerned with source term retrieval in the case of an accident in a nuclear power with off-site consequences. The goal is to optimize atmospheric dispersion model inputs using inverse modeling of gamma dose rate measurements (instantaneous or time-integrated). These are the most abundant type of measurements provided by various radiation monitoring networks across Europe and available continuously in near-real time. Usually, a source term of an accidental release comprises of a mixture of nuclides. Unfortunately, gamma dose rate measurements do not provide a direct information on the source term composition; however, physical properties of respective nuclides (deposition properties, decay half-life) can yield some insight. In the method presented, we assume that nuclide ratios are known at least approximately, e.g. from nuclide specific observations or reactor inventory and assumptions on the accident type. The source term can be in multiple phases, each being characterized by constant nuclide ratios. The method is an extension of a well-established source term inversion approach based on the optimization of an objective function (minimization of a cost function). This function has two quadratic terms: mismatch between model and measurements weighted by an observation error covariance matrix and the deviation of the solution from a first guess weighted by the first-guess error covariance matrix. For simplicity, both error covariance matrices are approximated as diagonal. Analytical minimization of the cost function leads to a liner system of equations. Possible negative parts of the solution are iteratively removed by the means of first guess error variance reduction. Nuclide ratios enter the problem in the form of additional linear equations, where the deviations from prescribed ratios are weighted by factors; the corresponding error variance allows us to control how strongly we want to impose the prescribed ratios. This introduces some freedom into the

  13. Calibration of an eye lens dosemeter in terms of Hp(3) to be used in interventional radiology

    NASA Astrophysics Data System (ADS)

    Borges, F. L. S.; Guimarães, M. C.; Da Silva, T. A.; Nogueira Tavares, M. S.

    2014-11-01

    Recently, the International Commission on Radiological Protection has reviewed epidemiological evidences suggesting that there were tissue reaction effects in the eye lens below the previously considered absorbed dose threshold. A new statement related to the eye lens was issued that changed the absorbed dose threshold and reduced the dose limits for occupationally exposed persons. As consequence, some planned exposures require eye lens dosimetry and a debate was raised on the adequacy of the dosimetric quantity and on its method of measurement. The aim of this work was to study the methodology for calibrating the EYE-DTM holder with a TLD-100H Harshaw chip detector and to determine its angular and energy dependences in terms of personal dose equivalent, Hp(3).

  14. Radiological Characterization Technical Report on Californium-252 Sealed Source Transuranic Debris Waste for the Off-Site Source Recovery Project at Los Alamos National Laboratory

    SciTech Connect

    Feldman, Alexander

    2014-04-24

    This document describes the development and approach for the radiological characterization of Cf-252 sealed sources for shipment to the Waste Isolation Pilot Plant. The report combines information on the nuclear material content of each individual source (mass or activity and date of manufacture) with information and data on the radionuclide distributions within the originating nuclear material. This approach allows for complete and accurate characterization of the waste container without the need to take additional measurements. The radionuclide uncertainties, developed from acceptable knowledge (AK) information regarding the source material, are applied to the summed activities in the drum. The AK information used in the characterization of Cf-252 sealed sources has been qualified by the peer review process, which has been reviewed and accepted by the Environmental Protection Agency.

  15. Characterization of Porous Materials as Radon Source and its Radiological Implications

    SciTech Connect

    Lopez-Coto, I.; Bolivar, J. P.; Mas, J. L.; Garcia-Tenorio, R.

    2008-08-07

    In this work, a magnitude is proposed in order to compare the potential radiological risk due to radon exposition generated by different materials, and a method based in the {sup 222}Rn accumulation technique is presented for its determination. The obtained results indicate that the proposed magnitude and their corresponding measurement methodology are useful in order to take decisions about the management of different kinds of porous materials.

  16. Source term evaluation model for high-level radioactive waste repository with decay chain build-up.

    PubMed

    Chopra, Manish; Sunny, Faby; Oza, R B

    2016-09-18

    A source term model based on two-component leach flux concept is developed for a high-level radioactive waste repository. The long-lived radionuclides associated with high-level waste may give rise to the build-up of activity because of radioactive decay chains. The ingrowths of progeny are incorporated in the model using Bateman decay chain build-up equations. The model is applied to different radionuclides present in the high-level radioactive waste, which form a part of decay chains (4n to 4n + 3 series), and the activity of the parent and daughter radionuclides leaching out of the waste matrix is estimated. Two cases are considered: one when only parent is present initially in the waste and another where daughters are also initially present in the waste matrix. The incorporation of in situ production of daughter radionuclides in the source is important to carry out realistic estimates. It is shown that the inclusion of decay chain build-up is essential to avoid underestimation of the radiological impact assessment of the repository. The model can be a useful tool for evaluating the source term of the radionuclide transport models used for the radiological impact assessment of high-level radioactive waste repositories. PMID:27337157

  17. Trace metal source terms in carbon sequestration environments.

    PubMed

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2013-01-01

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising; however, possible CO(2) or CO(2)-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define a range of concentrations that can be used as the trace element source term for reservoirs and leakage pathways in risk simulations. Storage source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from cements and sandstones, shales, carbonates, evaporites, and basalts from the Frio, In Salah, Illinois Basin, Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands, and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution was tracked by measuring solution concentrations over time under conditions (e.g., pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for maximum contaminant levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments because of the presence of CO(2). Results indicate that Cr and Pb released from sandstone reservoir and shale cap rocks exceed the MCLs by an order of magnitude, while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the trace element source term for reservoirs and leakage pathways in risk simulations to further evaluate the impact of leakage on groundwater quality. PMID:23215015

  18. Trace Metal Source Terms in Carbon Sequestration Environments

    SciTech Connect

    Karamalidis, Athanasios; Torres, Sharon G.; Hakala, Jacqueline A.; Shao, Hongbo; Cantrell, Kirk J.; Carroll, Susan A.

    2013-01-01

    ABSTRACT: Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising; however, possible CO2 or CO2-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define to provide a range of concentrations that can be used as the trace element source term for reservoirs and leakage pathways in risk simulations. Storage source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from cements and sandstones, shales, carbonates, evaporites, and basalts from the Frio, In Salah, Illinois Basin, Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands, and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution was tracked by measuring solution concentrations over time under conditions (e.g., pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for maximum contaminant levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments because of the presence of CO2. Results indicate that Cr and Pb released from sandstone reservoir and shale cap rocks exceed the MCLs byan order of magnitude, while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the trace element source term for reservoirs and leakage pathways in risk simulations to further evaluate the impact of leakage on groundwater quality.

  19. Trace Metal Source Terms in Carbon Sequestration Environments

    SciTech Connect

    Karamalidis, Athanasios K; Torres, Sharon G; Hakala, J Alexandra; Shao, Hongbo; Cantrell, Kirk J; Carroll, Susan

    2012-02-05

    Carbon dioxide sequestration in deep saline and depleted oil geologic formations is feasible and promising, however, possible CO₂ or CO₂-saturated brine leakage to overlying aquifers may pose environmental and health impacts. The purpose of this study was to experimentally define trace metal source terms from the reaction of supercritical CO₂, storage reservoir brines, reservoir and cap rocks. Storage reservoir source terms for trace metals are needed to evaluate the impact of brines leaking into overlying drinking water aquifers. The trace metal release was measured from sandstones, shales, carbonates, evaporites, basalts and cements from the Frio, In Salah, Illinois Basin – Decatur, Lower Tuscaloosa, Weyburn-Midale, Bass Islands and Grand Ronde carbon sequestration geologic formations. Trace metal dissolution is tracked by measuring solution concentrations over time under conditions (e.g. pressures, temperatures, and initial brine compositions) specific to the sequestration projects. Existing metrics for Maximum Contaminant Levels (MCLs) for drinking water as defined by the U.S. Environmental Protection Agency (U.S. EPA) were used to categorize the relative significance of metal concentration changes in storage environments due to the presence of CO₂. Results indicate that Cr and Pb released from sandstone reservoir and shale cap rock exceed the MCLs by an order of magnitude while Cd and Cu were at or below drinking water thresholds. In carbonate reservoirs As exceeds the MCLs by an order of magnitude, while Cd, Cu, and Pb were at or below drinking water standards. Results from this study can be used as a reasonable estimate of the reservoir and caprock source term to further evaluate the impact of leakage on groundwater quality.

  20. Long-term cycles in cosmic X-ray sources

    NASA Technical Reports Server (NTRS)

    Priedhorsky, W. C.; Holt, S. S.

    1987-01-01

    Data on long-term cycles in galactic X-ray sources are reviewed, and classes of variations are identified including precessional activity, recurrent outbursts in Population II sources, and Be/neutron star flare cycles. Cycles of 30-300 days have been found in LMC X-4, Her X-1, SS433, and Cyg X-1 which represent cyclic variations in both the inner and outer parts of the accretion disk. Quasi-periodic cycles with periods ranging from 1/2 to 2 years have been noted in several low-mass X-ray binaries. It is suggested that periodic outbursts in the Be/neutron star systems may result from variable mass transfer in a wide eccentric orbit.

  1. Development of alternate methods of determining integrated SMR source terms

    SciTech Connect

    Barry, Kenneth

    2014-06-10

    The Nuclear Energy Institute (NEI) Small Modular Reactor (SMR) Licensing Task Force (TF) has been evaluating licensing issues unique and important to iPWRs, ranking these issues, and developing NEI position papers for submittal to the U.S. Nuclear Regulatory Commission (NRC) during the past three years. Papers have been developed and submitted to the NRC in a range of areas including: Price-Anderson Act, NRC annual fees, security, modularity, and staffing. In December, 2012, NEI completed a draft position paper on SMR source terms and participated in an NRC public meeting presenting a summary of this paper, which was subsequently submitted to the NRC. One important conclusion of the source term paper was the evaluation and selection of high importance areas where additional research would have a significant impact on source terms. The highest ranked research area was iPWR containment aerosol natural deposition. The NRC accepts the use of existing aerosol deposition correlations in Regulatory Guide 1.183, but these were developed for large light water reactor (LWR) containments. Application of these correlations to an iPWR design has resulted in greater than a ten-fold reduction of containment airborne aerosol inventory as compared to large LWRs. Development and experimental justification of containment aerosol natural deposition correlations specifically for the unique iPWR containments is expected to result in a large reduction of design basis and beyond-design-basis accident source terms with concomitantly smaller dose to workers and the public. Therefore, NRC acceptance of iPWR containment aerosol natural deposition correlations will directly support the industry’s goal of reducing the Emergency Planning Zone (EPZ) for SMRs. Based on the results in this work, it is clear that thermophoresis is relatively unimportant for iPWRs. Gravitational settling is well understood, and may be the dominant process for a dry environment. Diffusiophoresis and enhanced

  2. Development of modified voxel phantoms for the numerical dosimetric reconstruction of radiological accidents involving external sources: implementation in SESAME tool.

    PubMed

    Courageot, Estelle; Sayah, Rima; Huet, Christelle

    2010-05-01

    Estimating the dose distribution in a victim's body is a relevant indicator in assessing biological damage from exposure in the event of a radiological accident caused by an external source. When the dose distribution is evaluated with a numerical anthropomorphic model, the posture and morphology of the victim have to be reproduced as realistically as possible. Several years ago, IRSN developed a specific software application, called the simulation of external source accident with medical images (SESAME), for the dosimetric reconstruction of radiological accidents by numerical simulation. This tool combines voxel geometry and the MCNP(X) Monte Carlo computer code for radiation-material interaction. This note presents a new functionality in this software that enables the modelling of a victim's posture and morphology based on non-uniform rational B-spline (NURBS) surfaces. The procedure for constructing the modified voxel phantoms is described, along with a numerical validation of this new functionality using a voxel phantom of the RANDO tissue-equivalent physical model. PMID:20371912

  3. Long-Term Stability of the NIST Standard Ultrasonic Source.

    PubMed

    Fick, Steven E

    2008-01-01

    The National Institute of Standards and Technology (NIST) Standard Ultrasonic Source (SUS) is a system comprising a transducer capable of output power levels up to 1 W at multiple frequencies between 1 MHz and 30 MHz, and an electrical impedance-matching network that allows the system to be driven by a conventional 50 Ω rf (radio-frequency) source. It is designed to allow interlaboratory replication of ultrasonic power levels with high accuracy using inexpensive readily available ancillary equipment. The SUS was offered for sale for 14 years (1985 to 1999). Each system was furnished with data for the set of calibration points (combinations of power level and frequency) specified by the customer. Of the systems that had been ordered with some calibration points in common, three were returned more than once to NIST for recalibration. Another system retained at NIST has been recalibrated periodically since 1984. The collective data for these systems comprise 9 calibration points and 102 measurements spanning a 17 year interval ending in 2001, the last year NIST ultrasonic power measurement services were available to the public. These data have been analyzed to compare variations in output power with frequency, power level, and time elapsed since the first calibration. The results verify the claim, made in the instruction sheet furnished with every SUS, that "long-term drift, if any, in the calibration of NIST Standard Sources is insignificant compared to the uncertainties associated with a single measurement of ultrasonic power by any method available at NIST." PMID:27096127

  4. Gamma Knife Radiosurgery for Skull Base Meningiomas: Long-Term Radiologic and Clinical Outcome

    SciTech Connect

    Han, Jung Ho; Kim, Dong Gyu Chung, Hyun-Tai; Park, Chul-Kee; Paek, Sun Ha; Kim, Chae-Yong; Jung, Hee-Won

    2008-12-01

    Purpose: To analyze the long-term outcomes in patients with skull base meningiomas (SBMNGs) treated with Gamma Knife radiosurgery (GKRS). Methods and Materials: Of the 98 consecutive patients with SBMNGs treated with GKRS between 1998 and 2002, 63 were followed up for more than 48 months. The mean ({+-}SD) age of the patients was 50 {+-} 12 years, the mean tumor volume was 6.5 cm{sup 3} (range, 0.5-18.4 cm{sup 3}), the mean marginal dose was 12.6 Gy (range, 7.0-20.0 Gy), and the mean follow-up duration was 77 {+-} 18 months. The mean number of shots was 13.7 {+-} 3.8. The tumor volume was decreased at the last follow-up in 28 patients (44.4%) and increased in 6 (9.6%). The actuarial tumor control rate was 90.2% at 5 years. No notable prognostic factor related to tumor control was identified. Ten patients (15.9%) with a cranial neuropathy showed unfavorable outcomes. The rate of improvement in patients with a cranial neuropathy was 45.1%. Age >70 years was likely correlated with an unfavorable outcome in patients with cranial neuropathy (odds ratio = 0.027; p = 0.025; 95% confidence interval 0.001-0.632). Cavernous sinus location was significantly associated with improvement of a cranial neuropathy (odds ratio = 7.314; p = 0.007; 95% confidence interval 1.707-31.34). Conclusions: Gamma Knife radiosurgery is an effective modality for the treatment of SBMNGs and provides favorable outcomes in patients with cranial neuropathy, even in the long-term follow-up period. However, radiosurgery for patients with no or only mild symptoms should be performed cautiously because neither complication rate is low enough to be negligible, especially in elderly patients. A cranial neuropathy by MNGs involving the cavernous sinus seems to have a higher chance of improvement after radiosurgery than other SBMNGs.

  5. Source term identification in atmospheric modelling via sparse optimization

    NASA Astrophysics Data System (ADS)

    Adam, Lukas; Branda, Martin; Hamburger, Thomas

    2015-04-01

    Inverse modelling plays an important role in identifying the amount of harmful substances released into atmosphere during major incidents such as power plant accidents or volcano eruptions. Another possible application of inverse modelling lies in the monitoring the CO2 emission limits where only observations at certain places are available and the task is to estimate the total releases at given locations. This gives rise to minimizing the discrepancy between the observations and the model predictions. There are two standard ways of solving such problems. In the first one, this discrepancy is regularized by adding additional terms. Such terms may include Tikhonov regularization, distance from a priori information or a smoothing term. The resulting, usually quadratic, problem is then solved via standard optimization solvers. The second approach assumes that the error term has a (normal) distribution and makes use of Bayesian modelling to identify the source term. Instead of following the above-mentioned approaches, we utilize techniques from the field of compressive sensing. Such techniques look for a sparsest solution (solution with the smallest number of nonzeros) of a linear system, where a maximal allowed error term may be added to this system. Even though this field is a developed one with many possible solution techniques, most of them do not consider even the simplest constraints which are naturally present in atmospheric modelling. One of such examples is the nonnegativity of release amounts. We believe that the concept of a sparse solution is natural in both problems of identification of the source location and of the time process of the source release. In the first case, it is usually assumed that there are only few release points and the task is to find them. In the second case, the time window is usually much longer than the duration of the actual release. In both cases, the optimal solution should contain a large amount of zeros, giving rise to the

  6. Informatics in radiology: Render: an online searchable radiology study repository.

    PubMed

    Dang, Pragya A; Kalra, Mannudeep K; Schultz, Thomas J; Graham, Steven A; Dreyer, Keith J

    2009-01-01

    Radiology departments are a rich source of information in the form of digital radiology reports and images obtained in patients with a wide spectrum of clinical conditions. A free text radiology report and image search application known as Render was created to allow users to find pertinent cases for a variety of purposes. Render is a radiology report and image repository that pools researchable information derived from multiple systems in near real time with use of (a) Health Level 7 links for radiology information system data, (b) periodic file transfers from the picture archiving and communication system, and (c) the results of natural language processing (NLP) analysis. Users can perform more structured and detailed searches with this application by combining different imaging and patient characteristics such as examination number; patient age, gender, and medical record number; and imaging modality. Use of NLP analysis allows a more effective search for reports with positive findings, resulting in the retrieval of more cases and terms having greater relevance. From the retrieved results, users can save images, bookmark examinations, and navigate to an external search engine such as Google. Render has applications in the fields of radiology education, research, and clinical decision support. PMID:19564253

  7. A comparison of world-wide uses of severe reactor accident source terms

    SciTech Connect

    Ang, M.L.; Frid, W.; Kersting, E.J.; Friederichs, H.G.; Lee, R.Y.; Meyer-Heine, A.; Powers, D.A.; Soda, K.; Sweet, D.

    1994-09-01

    The definitions of source terms to reactor containments and source terms to the environment are discussed. A comparison is made between the TID-14844 example source term and the alternative source term described in NUREG-1465. Comparisons of these source terms to the containments and those used in France, Germany, Japan, Sweden, and the United Kingdom are made. Source terms to the environment calculated in NUREG-1500 and WASH-1400 are discussed. Again, these source terms are compared to those now being used in France, Germany, Japan, Sweden, and the United Kingdom. It is concluded that source terms to the containment suggested in NUREG-1465 are not greatly more conservative than those used in other countries. Technical bases for the source terms are similar. The regulatory use of the current understanding of radionuclide behavior varies among countries.

  8. Tank waste source term inventory validation. Volume 1. Letter report

    SciTech Connect

    Brevick, C.H.; Gaddis, L.A.; Johnson, E.D.

    1995-04-28

    The sample data for selection of 11 radionuclides and 24 chemical analytes were extracted from six separate sample data sets, were arranged in a tabular format and were plotted on scatter plots for all of the 149 single-shell tanks, the 24 double-shell tanks and the four aging waste tanks. The solid and liquid sample data was placed in separate tables and plots. The sample data and plots were compiled from the following data sets: characterization raw sample data, recent core samples, D. Braun data base, Wastren (Van Vleet) data base, TRAC and HTCE inventories. This document is Volume I of the Letter Report entitled Tank Waste Source Term Inventory Validation.

  9. A radiological incident with a radioactive lightning rod source found in a vehicle used by film crewmembers: a case study.

    PubMed

    Ciraj-Bjelac, Olivera; Kovacevic, Milojko; Kosutic, Dusko; Arandjic, Danijela; Lazarevic, Djordje

    2010-10-01

    An overview of radiological incident involving radiation source from a lightning rod (152Eu/154Eu), together with dose estimation for individuals exposed to ionising radiation is given in the paper. The cause of the incident was an orphaned source from a lightning rod. The dose received by individuals was assessed using a retrospective dosimetry technique, based on the information on behaviour of individuals and results of dose rate measurements in the vicinity of the source. Several people have been exposed to relatively high dose rates for an extended period of time. The conservatively estimated cumulative dose values for two categories of individuals were 50 and 40 mSv, respectively, which are significantly higher than annual dose limit for public exposure of 1 mSv. The need to identify radioactive sources incorporated in radioactive lightning rods, to maintain control and accountability and to remove and dispose of them properly along with appropriate record keeping in Serbia was highlighted. These activities would reduce the probability of occurrence of radiation incidents in Serbia. PMID:20639515

  10. Radiological source terms resulting from sabotage to transportation casks: Final report

    SciTech Connect

    Miller, N E; Fentiman, A W; Kuhlman, M R; Ebersole, H N; Trott, B D; Orban, J E

    1986-11-01

    The Nuclear Regulatory Commission (NRC) promulgated a rule, 10 CFR 73.37, which established requirements for safeguarding shipments of spent fuel to reduce the risk from acts of sabotage of highly radioactive materials. After the rule became effective, experimental programs conducted by Battelle for the NRC and by Sandia for the DOE showed the consequences of an attack using explosives on a shipment of PWR spent fuel were significantly less than had been indicated by earlier analytical studies. As a result, NRC is considering modifying the safeguards requirements. In support of NRC's efforts to modify the rule, Battelle has conducted additional experimental studies to evaluate the consequences of attacks on shipments of high-temperature gas-cooled reactor (HTGR) spent fuel, nonpower reactor (NPR) spent fuel, and vitrified high-level waste (HLW). Model casks containing surrogates of the spent fuels or high-level waste were penetrated by the jet from a precision shaped charge. Air samples collected after each test were used to estimate the quantities of respirable material released after the cask was penetrated. Results of the tests were scaled by specially developed scaling factors to estimate the releases that may occur from attacks on full-sized shipments of the materials. It was concluded that the sabotage of shipments of HTGR spent fuel, NPR spent fuel, or vitrified HLW should have no greater consequences than those predicted for shipments of PWR spent fuel.

  11. LMFBR source term experiments in the Fuel Aerosol Simulant Test (FAST) facility

    SciTech Connect

    Petrykowski, J.C.; Longest, A.W.

    1985-01-01

    The transport of uranium dioxide (UO/sub 2/) aerosol through liquid sodium was studied in a series of ten experiments in the Fuel Aerosol Simulant Test (FAST) facility at Oak Ridge National Laboratory (ORNL). The experiments were designed to provide a mechanistic basis for evaluating the radiological source term associated with a postulated, energetic core disruptive accident (CDA) in a liquid metal fast breeder reactor (LMFBR). Aerosol was generated by capacitor discharge vaporization of UO/sub 2/ pellets which were submerged in a sodium pool under an argon cover gas. Measurements of the pool and cover gas pressures were used to study the transport of aerosol contained by vapor bubbles within the pool. Samples of cover gas were filtered to determine the quantity of aerosol released from the pool. The depth at which the aerosol was generated was found to be the most critical parameter affecting release. The largest release was observed in the baseline experiment where the sample was vaporized above the sodium pool. In the nine ''undersodium'' experiments aerosol was generated beneath the surface of the pool at depths varying from 30 to 1060 mm. The mass of aerosol released from the pool was found to be a very small fraction of the original specimen. It appears that the bulk of aerosol was contained by bubbles which collapsed within the pool. 18 refs., 11 figs., 4 tabs.

  12. Implementation of a source term control program in a mature boiling water reactor.

    PubMed

    Vargo, G J; Jarvis, A J; Remark, J F

    1991-06-01

    The implementation and results of a source term control program implemented at the James A. FitzPatrick Nuclear Power Plant (JAF), a mature boiling water reactor (BWR) facility that has been in commercial operation since 1975, are discussed. Following a chemical decontamination of the reactor water recirculation piping in the Reload 8/Cycle 9 refueling outage in 1988, hydrogen water chemistry (HWC) and feedwater Zn addition were implemented. This is the first application of both HWC and feedwater Zn addition in a BWR facility. The radiological benefits and impacts of combined operation of HWC and feedwater Zn addition at JAF during Cycle 9 are detailed and summarized. The implementation of hydrogen water chemistry resulted in a significant transport of corrosion products within the reactor coolant system that was greater than anticipated. Feedwater Zn addition appears to be effective in controlling buildup of other activated corrosion products such as 60Co on reactor water recirculation piping; however, adverse impacts were encountered. The major adverse impact of feedwater Zn addition is the production of 65Zn that is released during plant outages and operational transients. PMID:2032839

  13. SESAME: a software tool for the numerical dosimetric reconstruction of radiological accidents involving external sources and its application to the accident in Chile in December 2005.

    PubMed

    Huet, C; Lemosquet, A; Clairand, I; Rioual, J B; Franck, D; de Carlan, L; Aubineau-Lanièce, I; Bottollier-Depois, J F

    2009-01-01

    Estimating the dose distribution in a victim's body is a relevant indicator in assessing biological damage from exposure in the event of a radiological accident caused by an external source. This dose distribution can be assessed by physical dosimetric reconstruction methods. Physical dosimetric reconstruction can be achieved using experimental or numerical techniques. This article presents the laboratory-developed SESAME--Simulation of External Source Accident with MEdical images--tool specific to dosimetric reconstruction of radiological accidents through numerical simulations which combine voxel geometry and the radiation-material interaction MCNP(X) Monte Carlo computer code. The experimental validation of the tool using a photon field and its application to a radiological accident in Chile in December 2005 are also described. PMID:19066489

  14. [One third of Danish doctors specializing in diagnostic radiology do not feel sufficiently equipped in terms of medical expertise].

    PubMed

    Lange, Benedicte; Carlsen, Charlotte Green; Jurik, Anne Grethe

    2014-02-01

    An internet-based survey among Danish doctors specializing in diagnostic radiology revealed differences with respect to the length of internships at regional and university hospitals as well as the educational environment. The university hospitals were generally evaluated to have the best educational facilities except within practical skills. Therefore, it seems necessary to optimize the educational environment at regional hospitals, especially within medical expertise and scientific skills which are key elements regarding continuous development and quality assurance within radiology. PMID:25347440

  15. Verification test calculations for the Source Term Code Package

    SciTech Connect

    Denning, R S; Wooton, R O; Alexander, C A; Curtis, L A; Cybulskis, P; Gieseke, J A; Jordan, H; Lee, K W; Nicolosi, S L

    1986-07-01

    The purpose of this report is to demonstrate the reasonableness of the Source Term Code Package (STCP) results. Hand calculations have been performed spanning a wide variety of phenomena within the context of a single accident sequence, a loss of all ac power with late containment failure, in the Peach Bottom (BWR) plant, and compared with STCP results. The report identifies some of the limitations of the hand calculation effort. The processes involved in a core meltdown accident are complex and coupled. Hand calculations by their nature must deal with gross simplifications of these processes. Their greatest strength is as an indicator that a computer code contains an error, for example that it doesn't satisfy basic conservation laws, rather than in showing the analysis accurately represents reality. Hand calculations are an important element of verification but they do not satisfy the need for code validation. The code validation program for the STCP is a separate effort. In general the hand calculation results show that models used in the STCP codes (e.g., MARCH, TRAP-MELT, VANESA) obey basic conservation laws and produce reasonable results. The degree of agreement and significance of the comparisons differ among the models evaluated. 20 figs., 26 tabs.

  16. Evaluation of source-term data for plutonium aerosolization

    SciTech Connect

    Haschke, J.M.

    1992-07-01

    Relevant data are reviewed and evaluated in an effort to define the time dependence and maximum value of the source term for plutonium aerosolization during a fuel fire. The rate of plutonium oxidation at high temperatures is a major determinant of the time dependence. Analysis of temperature-time data for oxidation of plutonium shows that the rate is constant (0.2 g PUO{sub 2}/cm{sup 2} of metal surface per min) and independent of temperature above 500{degrees}C. Total mass and particle distributions are derived for oxide products formed by reactions of plutonium metal and hydride. The mass distributions for products of all metal-gas reactions are remarkably similar with approximately 0.07 mass% of the oxide particles having geometric diameters {le} 10 {mu}m. In comparison, 25 mass% of the oxide formed by the PuH{sub 2}+O{sub 2} reaction is in this range. Experimental values of mass fractions released during oxidation are evaluated and factors that alter the release fraction are discussed.

  17. SOURCE TERM TARGETED THRUST FY 2005 NEW START PROJECTS

    SciTech Connect

    NA

    2005-10-05

    While a significant amount of work has been devoted to developing thermodynamic data. describing the sorption of radionuclides to iron oxides and other geomedia, little data exist to describe the interaction of key radionuclides found in high-level radioactive waste with the uranium surfaces expected in corroded spent nuclear fuel (SNF) waste packages. Recent work indicates that actinide adsorption to the U(VI) solids expected in the engineered barrier system may play a key role in the reduction of dissolved concentrations of radionuclides such as Np(V). However, little is known about the mechanism(s) of adsorption, nor are the thermodynamic data available to represent the phenomenon in predictive modeling codes. Unfortunately, this situation makes it difficult to consider actinide adsorption to the U(VI) silicates in either geochemical or performance assessment (PA) predictions. The primary goal in the Source Term Targeted Thrust area is to ''study processes that control radionuclide release from the waste form''. Knowledge of adsorption of actinides to U(VI) silicate solids its and parameterization in geochemical models will be an important step towards this goal.

  18. The Linac Coherent Light Source at SLAC. Radiological Considerations and Shielding calculations

    SciTech Connect

    Mao, X.S.; Fasso, A.; Nakao, N.; Rokni, S.H.; Vincke, H.; /SLAC

    2005-12-02

    The Linac Coherent Light Source (LCLS) at SLAC will be the world's first X-ray free electron laser when it becomes operational in 2009. Pulses of X-ray laser light from LCLS will be many orders of magnitude brighter and several orders of magnitude shorter than what can be produced by other X-ray sources available in the world. These characteristics will enable frontier new science in many areas. This paper describes the LCLS beam parameters and its lay-out. Results of the Monte Carlo calculations for the shielding design of the electron dump line, radiation damage to undulator, the residual radiation and the soil activation around the electron dump are presented.

  19. Long-Term Stability of Radio Sources in VLBI Analysis

    NASA Technical Reports Server (NTRS)

    Engelhardt, Gerald; Thorandt, Volkmar

    2010-01-01

    Positional stability of radio sources is an important requirement for modeling of only one source position for the complete length of VLBI data of presently more than 20 years. The stability of radio sources can be verified by analyzing time series of radio source coordinates. One approach is a statistical test for normal distribution of residuals to the weighted mean for each radio source component of the time series. Systematic phenomena in the time series can thus be detected. Nevertheless, an inspection of rate estimation and weighted root-mean-square (WRMS) variations about the mean is also necessary. On the basis of the time series computed by the BKG group in the frame of the ICRF2 working group, 226 stable radio sources with an axis stability of 10 as could be identified. They include 100 ICRF2 axes-defining sources which are determined independently of the method applied in the ICRF2 working group. 29 stable radio sources with a source structure index of less than 3.0 can also be used to increase the number of 295 ICRF2 defining sources.

  20. Dense Plasma Focus With High Energy Helium Beams for Radiological Source Replacement

    NASA Astrophysics Data System (ADS)

    Schmidt, Andrea; Ellsworth, Jennifer; Falabella, Steve; Link, Anthony; Rusnak, Brian; Sears, Jason; Tang, Vincent

    2014-10-01

    A dense plasma focus (DPF) is a compact accelerator that can produce intense high energy ion beams (multiple MeV). It could be used in place of americium-beryllium (AmBe) neutron sources in applications such as oil well logging if optimized to produce high energy helium beams. AmBe sources produce neutrons when 5.5 MeV alphas emitted from the Am interact with the Be. However, due to the very small alpha-Be cross section for alphas <2 MeV, an AmBe source replacement would have to accelerate ~0.15 μC of He to 2 + MeV in order to produce 107 neutrons per pulse. We are using our particle in cell (PIC) model in LSP of a 4 kJ dense plasma focus discharge to guide the optimization of a compact DPF for the production of high-energy helium beam. This model is fluid for the run-down phase, and then transitions to fully kinetic prior to the pinch in order to include kinetic effects such as ion beam formation and anomalous resistivity. An external pulsed-power driver circuit is used at the anode-cathode boundary. Simulations will be benchmarked to He beam measurements using filtered and time-of-flight Faraday cup diagnostics. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work supported by US DOE/NA-22 Office of Non-proliferation Research and Development. Computing support for this work came from the LLNL Institutional Computing Grand Challenge program.

  1. 7 CFR 1822.268 - Rates, terms, and source of funds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Rates, terms, and source of funds. 1822.268 Section... Site Loan Policies, Procedures, and Authorizations § 1822.268 Rates, terms, and source of funds. (a... security interest of the Government. (c) Source of funds. Loans under this subpart will be made as...

  2. 7 CFR 1822.268 - Rates, terms, and source of funds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false Rates, terms, and source of funds. 1822.268 Section... Site Loan Policies, Procedures, and Authorizations § 1822.268 Rates, terms, and source of funds. (a... security interest of the Government. (c) Source of funds. Loans under this subpart will be made as...

  3. 7 CFR 1822.268 - Rates, terms, and source of funds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Rates, terms, and source of funds. 1822.268 Section... Site Loan Policies, Procedures, and Authorizations § 1822.268 Rates, terms, and source of funds. (a... security interest of the Government. (c) Source of funds. Loans under this subpart will be made as...

  4. 7 CFR 1822.268 - Rates, terms, and source of funds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Rates, terms, and source of funds. 1822.268 Section... Site Loan Policies, Procedures, and Authorizations § 1822.268 Rates, terms, and source of funds. (a... security interest of the Government. (c) Source of funds. Loans under this subpart will be made as...

  5. 7 CFR 1822.268 - Rates, terms, and source of funds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Rates, terms, and source of funds. 1822.268 Section... Site Loan Policies, Procedures, and Authorizations § 1822.268 Rates, terms, and source of funds. (a... security interest of the Government. (c) Source of funds. Loans under this subpart will be made as...

  6. Radiologic and nuclear medicine studies in the United States and worldwide: frequency, radiation dose, and comparison with other radiation sources--1950-2007.

    PubMed

    Mettler, Fred A; Bhargavan, Mythreyi; Faulkner, Keith; Gilley, Debbie B; Gray, Joel E; Ibbott, Geoffrey S; Lipoti, Jill A; Mahesh, Mahadevappa; McCrohan, John L; Stabin, Michael G; Thomadsen, Bruce R; Yoshizumi, Terry T

    2009-11-01

    The U.S. National Council on Radiation Protection and Measurements and United Nations Scientific Committee on Effects of Atomic Radiation each conducted respective assessments of all radiation sources in the United States and worldwide. The goal of this article is to summarize and combine the results of these two publicly available surveys and to compare the results with historical information. In the United States in 2006, about 377 million diagnostic and interventional radiologic examinations and 18 million nuclear medicine examinations were performed. The United States accounts for about 12% of radiologic procedures and about one-half of nuclear medicine procedures performed worldwide. In the United States, the frequency of diagnostic radiologic examinations has increased almost 10-fold (1950-2006). The U.S. per-capita annual effective dose from medical procedures has increased about sixfold (0.5 mSv [1980] to 3.0 mSv [2006]). Worldwide estimates for 2000-2007 indicate that 3.6 billion medical procedures with ionizing radiation (3.1 billion diagnostic radiologic, 0.5 billion dental, and 37 million nuclear medicine examinations) are performed annually. Worldwide, the average annual per-capita effective dose from medicine (about 0.6 mSv of the total 3.0 mSv received from all sources) has approximately doubled in the past 10-15 years. PMID:19789227

  7. Long-term optical behavior of 114 extragalactic sources

    NASA Astrophysics Data System (ADS)

    Pica, A. J.; Pollock, J. T.; Smith, A. G.; Leacock, R. J.; Edwards, P. L.; Scott, R. L.

    1980-11-01

    Photographic observations of over 200 quasars and related objects have been obtained at the Rosemary Hill Observatory since 1968. Twenty that are optically violent variables were reported on by Pollock et al. (1979). This paper presents data for 114 less active sources, 58 of which exhibit optical variations at a confidence level of 95% or greater. Light curves are given for the 26 most active sources. In addition, the overall monitoring program at the Observatory is reviewed, and information on the status of 206 objects is provided.

  8. Radiological Assessment Survey of the Vance road Facility Source Vault Building Materials, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee

    SciTech Connect

    J. R. Morton

    2000-09-01

    From the 1950s, the Vance Road laboratory was the site of extensive nuclear medical research and involved the used of numerous radionuclides. These nuclides were stored in a source vault stored on the first floor of the facility. Nuclear medical research is no longer conducted in this facility, and the source vault was remediated in preparation for converting the area to office space and general use. The Environmental Survey and Site Assessment Program (ESSAP) of ORISE performed a radiological assessment survey of the source vault and its associated miscellaneous building materials and laboratory equipment in preparation for the conversion to general use space.

  9. Modeling the voice source in terms of spectral slopes.

    PubMed

    Garellek, Marc; Samlan, Robin; Gerratt, Bruce R; Kreiman, Jody

    2016-03-01

    A psychoacoustic model of the voice source spectrum is proposed. The model is characterized by four spectral slope parameters: the difference in amplitude between the first two harmonics (H1-H2), the second and fourth harmonics (H2-H4), the fourth harmonic and the harmonic nearest 2 kHz in frequency (H4-2 kHz), and the harmonic nearest 2 kHz and that nearest 5 kHz (2 kHz-5 kHz). As a step toward model validation, experiments were conducted to establish the acoustic and perceptual independence of these parameters. In experiment 1, the model was fit to a large number of voice sources. Results showed that parameters are predictable from one another, but that these relationships are due to overall spectral roll-off. Two additional experiments addressed the perceptual independence of the source parameters. Listener sensitivity to H1-H2, H2-H4, and H4-2 kHz did not change as a function of the slope of an adjacent component, suggesting that sensitivity to these components is robust. Listener sensitivity to changes in spectral slope from 2 kHz to 5 kHz depended on complex interactions between spectral slope, spectral noise levels, and H4-2 kHz. It is concluded that the four parameters represent non-redundant acoustic and perceptual aspects of voice quality. PMID:27036277

  10. Evaluation of the Transient Hydrologic Source Term for the Cambric Underground Nuclear Test at Frenchman Flat, Nevada test Site

    SciTech Connect

    Carle, S F; Maxwell, R M; Pawloski, G A; Shumaker, D E; Tompson, A B; Zavarin, M

    2006-12-12

    The objective of Phase II HST work is to develop a better understanding of the evolution of the HST for 1,000 years at the CAMBRIC underground nuclear test site in Frenchman Flat at the NTS. This work provides a better understanding of activities as they actually occurred, incorporates improvements based on recent data acquisition, and provides a basis to use the CAMBRIC site for model validation and monitoring activities as required by the UGTA Project. CAMBRIC was the only test in Frenchman Flat detonated under the water table and best represents a fully saturated environment. These simulations are part of a broad Phase II Frenchman Flat Corrective Action Unit (CAU) flow and transport modeling effort being conducted by the Department of Energy (DOE) Underground Test Area (UGTA) Project. HST simulations provide, either directly or indirectly, the source term used in the CAU model to calculate a contaminant boundary. Work described in this report augments Phase I HST calculations at CAMBRIC conducted by Tompson et al. (1999) and Pawloski et al. (2001). Phase II HST calculations have been organized to calculate source terms under two scenarios: (1) A representation of the transient flow and radionuclide release behavior at the CAMBRIC site that is more specific than Tompson et al. (1999). This model reflects the influence of the background hydraulic gradient, residual test heat, pumping experiment, and ditch recharge, and takes into account improved data sources and modeling approaches developed since the previous efforts. Collectively, this approach will be referred to as the transient CAMBRIC source term. This report describes the development of the transient CAMBRIC HST. (2) A generic release model made under steady-state flow conditions, in the absence of any transient effects, at the same site with the same radiologic source term. This model is for use in the development of simpler release models for the other nine underground test sites in the Frenchman Flat

  11. Diagnostic radiology

    SciTech Connect

    Leeds, N.E.; Jacobson, H.G.

    1986-10-17

    Developments in the burgeoning field of diagnostic radiology have continued apace. Four areas that represent either subspecialities or technological advances in diagnostic radiology will be considered in this report: ultrasonography, interventional radiology, nuclear radiology, and magnetic resonance. In no sense is the exclusion of other subdisciplines and modalities (eg, pediatric radiology, computed tomography) and indication of their of importance or their failure to include innovative concepts.

  12. Development of a tool dedicated to the evaluation of hydrogen term source for technological Wastes: assumptions, physical models, and validation

    SciTech Connect

    Lamouroux, C.

    2013-07-01

    In radioactive waste packages hydrogen is generated, in one hand, from the radiolysis of wastes (mainly organic materials) and, in the other hand, from the radiolysis of water content in the cement matrix. In order to assess hydrogen generation 2 tools based on operational models have been developed. One is dedicated to the determination of the hydrogen source term issues from the radiolysis of the wastes: the STORAGE tool (Simulation Tool Of Emission Radiolysis Gas), the other deals with the hydrogen source term gas, produced by radiolysis of the cement matrices (the Damar tool). The approach used by the STORAGE tool for assessing the production rate of radiolysis gases is divided into five steps: 1) Specification of the data packages, in particular, inventories and radiological materials defined for a package medium; 2) Determination of radiochemical yields for the different constituents and the laws of behavior associated, this determination of radiochemical yields is made from the PRELOG database in which radiochemical yields in different irradiation conditions have been compiled; 3) Definition of hypothesis concerning the composition and the distribution of contamination inside the package to allow assessment of the power absorbed by the constituents; 4) Sum-up of all the contributions; And finally, 5) validation calculations by comparison with a reduced sampling of packages. Comparisons with measured values confirm the conservative character of the methodology and give confidence in the safety margins for safety analysis report.

  13. Energy decay for viscoelastic plates with distributed delay and source term

    NASA Astrophysics Data System (ADS)

    Mustafa, Muhammad I.; Kafini, Mohammad

    2016-06-01

    In this paper we consider a viscoelastic plate equation with distributed delay and source term. Under suitable conditions on the delay and source term, we establish an explicit and general decay rate result without imposing restrictive assumptions on the behavior of the relaxation function at infinity. Our result allows a wider class of relaxation functions and improves earlier results in the literature.

  14. On the numerical solution of hyperbolic equations with singular source terms

    NASA Astrophysics Data System (ADS)

    Turk, Irfan; Ashyraliyev, Maksat

    2014-08-01

    A numerical study for hyperbolic equations having singular source terms is presented. Singular in the sense that within the spatial domain the source is defined by a Dirac delta function. Solutions of such problems will have discontinuities which forms an obstacle for standard numerical methods. In this paper, a fifth order flux implicit WENO method with non-uniform meshes is studied for approximate solutions of hyperbolic equations having singular source terms. Numerical examples are provided.

  15. Source-term reevaluation for US commercial nuclear power reactors: a status report

    SciTech Connect

    Herzenberg, C.L.; Ball, J.R.; Ramaswami, D.

    1984-12-01

    Only results that had been discussed publicly, had been published in the open literature, or were available in preliminary reports as of September 30, 1984, are included here. More than 20 organizations are participating in source-term programs, which have been undertaken to examine severe accident phenomena in light-water power reactors (including the chemical and physical behavior of fission products under accident conditions), update and reevaluate source terms, and resolve differences between predictions and observations of radiation releases and related phenomena. Results from these source-term activities have been documented in over 100 publications to date.

  16. Source term model evaluations for the low-level waste facility performance assessment

    SciTech Connect

    Yim, M.S.; Su, S.I.

    1995-12-31

    The estimation of release of radionuclides from various waste forms to the bottom boundary of the waste disposal facility (source term) is one of the most important aspects of LLW facility performance assessment. In this work, several currently used source term models are comparatively evaluated for the release of carbon-14 based on a test case problem. The models compared include PRESTO-EPA-CPG, IMPACTS, DUST and NEFTRAN-II. Major differences in assumptions and approaches between the models are described and key parameters are identified through sensitivity analysis. The source term results from different models are compared and other concerns or suggestions are discussed.

  17. Unclassified Source Term and Radionuclide Data for Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nevada, Revision 1

    SciTech Connect

    Peter Martian

    2009-05-01

    This report documents the evaluation of the information and data available on the unclassified source term and radionuclide contamination for CAU 97: Yucca Flat/Climax Mine. The total residual inventory of radionuclides associated with one or more tests is known as the radiologic source term (RST). The RST is comprised of radionuclides in water, glass, or other phases or mineralogic forms. The hydrologic source term (HST) of an underground nuclear test is the portion of the total RST that is released into the groundwater over time following the test. In this report, the HST represents radionuclide release some time after the explosion and does not include the rapidly evolving mechanical, thermal, and chemical processes during the explosion. The CAU 97: Yucca Flat/Climax Mine has many more detonations and a wider variety of settings to consider compared to other CAUs. For instance, the source term analysis and evaluation performed for CAUs 101 and 102: Central and Western Pahute Mesa and CAU 98: Frenchman Flat did not consider vadose zone attenuation because many detonations were located near or below the water table. However, the large number of Yucca Flat/Climax Mine tests and the location of many tests above the water table warrant a more robust analysis of the unsaturated zone.

  18. Source terms: an investigation of uncertainties, magnitudes, and recommendations for research. [PWR; BWR

    SciTech Connect

    Levine, S.; Kaiser, G. D.; Arcieri, W. C.; Firstenberg, H.; Fulford, P. J.; Lam, P. S.; Ritzman, R. L.; Schmidt, E. R.

    1982-03-01

    The purpose of this document is to assess the state of knowledge and expert opinions that exist about fission product source terms from potential nuclear power plant accidents. This is so that recommendations can be made for research and analyses which have the potential to reduce the uncertainties in these estimated source terms and to derive improved methods for predicting their magnitudes. The main reasons for writing this report are to indicate the major uncertainties involved in defining realistic source terms that could arise from severe reactor accidents, to determine which factors would have the most significant impact on public risks and emergency planning, and to suggest research and analyses that could result in the reduction of these uncertainties. Source terms used in the conventional consequence calculations in the licensing process are not explicitly addressed.

  19. Source Term Model for Steady Micro Jets in a Navier-Stokes Computer Code

    NASA Technical Reports Server (NTRS)

    Waithe, Kenrick A.

    2005-01-01

    A source term model for steady micro jets was implemented into a non-proprietary Navier-Stokes computer code, OVERFLOW. The source term models the mass flow and momentum created by a steady blowing micro jet. The model is obtained by adding the momentum and mass flow created by the jet to the Navier-Stokes equations. The model was tested by comparing with data from numerical simulations of a single, steady micro jet on a flat plate in two and three dimensions. The source term model predicted the velocity distribution well compared to the two-dimensional plate using a steady mass flow boundary condition, which was used to simulate a steady micro jet. The model was also compared to two three-dimensional flat plate cases using a steady mass flow boundary condition to simulate a steady micro jet. The three-dimensional comparison included a case with a grid generated to capture the circular shape of the jet and a case without a grid generated for the micro jet. The case without the jet grid mimics the application of the source term. The source term model compared well with both of the three-dimensional cases. Comparisons of velocity distribution were made before and after the jet and Mach and vorticity contours were examined. The source term model allows a researcher to quickly investigate different locations of individual or several steady micro jets. The researcher is able to conduct a preliminary investigation with minimal grid generation and computational time.

  20. A second order operator splitting method for Allen-Cahn type equations with nonlinear source terms

    NASA Astrophysics Data System (ADS)

    Lee, Hyun Geun; Lee, June-Yub

    2015-08-01

    Allen-Cahn (AC) type equations with nonlinear source terms have been applied to a wide range of problems, for example, the vector-valued AC equation for phase separation and the phase-field equation for dendritic crystal growth. In contrast to the well developed first and second order methods for the AC equation, not many second order methods are suggested for the AC type equations with nonlinear source terms due to the difficulties in dealing with the nonlinear source term numerically. In this paper, we propose a simple and stable second order operator splitting method. A core idea of the method is to decompose the original equation into three subequations with the free-energy evolution term, the heat evolution term, and a nonlinear source term, respectively. It is important to combine these three subequations in proper order to achieve the second order accuracy and stability. We propose a method with a half-time free-energy evolution solver, a half-time heat evolution solver, a full-time midpoint solver for the nonlinear source term, and a half-time heat evolution solver followed by a final half-time free-energy evolution solver. We numerically demonstrate the second order accuracy of the new numerical method through the simulations of the phase separation and the dendritic crystal growth.

  1. Unclassified Source Term and Radionuclide Data for Corrective Action Unit 98: Frenchman Flat Nevada Test Site, Nevada, Rev. No.: 0

    SciTech Connect

    Farnham, Irene

    2005-09-01

    more tests is known as the radiologic source term (RST). The RST is comprised of radionuclides in water, glass, or other phases or mineralogic forms. This evaluation was conducted in support of the development of a CAU contaminant transport model for the Frenchman Flat CAU.

  2. Source Term Model for Vortex Generator Vanes in a Navier-Stokes Computer Code

    NASA Technical Reports Server (NTRS)

    Waithe, Kenrick A.

    2004-01-01

    A source term model for an array of vortex generators was implemented into a non-proprietary Navier-Stokes computer code, OVERFLOW. The source term models the side force created by a vortex generator vane. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on the local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low profile vortex generator vane on a flat plate. In addition, the model was compared to experimental data of an S-duct with 22 co-rotating, low profile vortex generators. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator on a flat plate without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream-wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data. The peak vorticity and its location were also predicted very well when compared to numerical simulations and experimental data. The circulation predicted by the source term model matches the prediction of the numerical simulation. The source term model predicted the engine fan face distortion and total pressure recovery of the S-duct with 22 co-rotating vortex generators very well. The source term model allows a researcher to quickly investigate different locations of individual or a row of vortex generators. The researcher is able to conduct a preliminary investigation with minimal grid generation and computational time.

  3. NOTE: Development of modified voxel phantoms for the numerical dosimetric reconstruction of radiological accidents involving external sources: implementation in SESAME tool

    NASA Astrophysics Data System (ADS)

    Courageot, Estelle; Sayah, Rima; Huet, Christelle

    2010-05-01

    Estimating the dose distribution in a victim's body is a relevant indicator in assessing biological damage from exposure in the event of a radiological accident caused by an external source. When the dose distribution is evaluated with a numerical anthropomorphic model, the posture and morphology of the victim have to be reproduced as realistically as possible. Several years ago, IRSN developed a specific software application, called the simulation of external source accident with medical images (SESAME), for the dosimetric reconstruction of radiological accidents by numerical simulation. This tool combines voxel geometry and the MCNP(X) Monte Carlo computer code for radiation-material interaction. This note presents a new functionality in this software that enables the modelling of a victim's posture and morphology based on non-uniform rational B-spline (NURBS) surfaces. The procedure for constructing the modified voxel phantoms is described, along with a numerical validation of this new functionality using a voxel phantom of the RANDO tissue-equivalent physical model.

  4. Imaging and radiology

    MedlinePlus

    Interventional radiology; Diagnostic radiology; X-ray imaging ... DIAGNOSTIC RADIOLOGY Diagnostic radiology helps health care professionals see structures inside your body. Doctors that specialize in the ...

  5. Imaging and radiology

    MedlinePlus

    Interventional radiology; Diagnostic radiology; X-ray imaging ... DIAGNOSTIC RADIOLOGY Diagnostic radiology helps health care professionals see structures inside your body. Doctors that specialize in the interpretation ...

  6. Observation-based source terms in the third-generation wave model WAVEWATCH

    NASA Astrophysics Data System (ADS)

    Zieger, Stefan; Babanin, Alexander V.; Erick Rogers, W.; Young, Ian R.

    2015-12-01

    Measurements collected during the AUSWEX field campaign, at Lake George (Australia), resulted in new insights into the processes of wind wave interaction and whitecapping dissipation, and consequently new parameterizations of the input and dissipation source terms. The new nonlinear wind input term developed accounts for dependence of the growth on wave steepness, airflow separation, and for negative growth rate under adverse winds. The new dissipation terms feature the inherent breaking term, a cumulative dissipation term and a term due to production of turbulence by waves, which is particularly relevant for decaying seas and for swell. The latter is consistent with the observed decay rate of ocean swell. This paper describes these source terms implemented in WAVEWATCH III ®and evaluates the performance against existing source terms in academic duration-limited tests, against buoy measurements for windsea-dominated conditions, under conditions of extreme wind forcing (Hurricane Katrina), and against altimeter data in global hindcasts. Results show agreement by means of growth curves as well as integral and spectral parameters in the simulations and hindcast.

  7. Long-term risk in a recently active volcanic system: Evaluation of doses and indoor radiological risk in the quaternary Vulsini Volcanic District (Central Italy)

    NASA Astrophysics Data System (ADS)

    Capaccioni, B.; Cinelli, G.; Mostacci, D.; Tositti, L.

    2012-12-01

    Volcanic rocks in the Vulsini Volcanic District (Central Italy) contain high concentrations of 238U, 232Th and 40K due to subduction-related metasomatic enrichment of incompatible elements in the mantle source coupled with magma differentiation within the upper crust. Due to their favorable mechanical properties they have been extensively used for construction since the Etruscan age. In the old buildings of the Bolsena village, one of the most populated ancient village in the area, the major source of indoor radioactivity is 222Rn, a radioactive noble gas descendant of 238U. Direct 222Rn indoor measurements have detected extremely high values in the old center due to the combined effect of building materials, radon fluxes from the volcanic basement and low air exchange rates. In these cases the evaluated risk of developing lung cancer within a 75 year lifetime reaches up to 40% for ever smokers. Simulations of "standard rooms" built with different tuffs and lavas collected from the Vulsini Volcanic District have also provided estimations of the effective doses and lifetime risk for radiogenic cancer. Other than by the method adopted for calculation, the total evaluated risk for each volcanic rock depends on different parameters, such as: radionuclide content, radon emanation power, occupancy factor and air exchange rate. Occupancy factor and air exchange rate appear as the only controlling parameters able to mitigate the indoor radiological risk.

  8. Informatics in radiology: radiology gamuts ontology: differential diagnosis for the Semantic Web.

    PubMed

    Budovec, Joseph J; Lam, Cesar A; Kahn, Charles E

    2014-01-01

    The Semantic Web is an effort to add semantics, or "meaning," to empower automated searching and processing of Web-based information. The overarching goal of the Semantic Web is to enable users to more easily find, share, and combine information. Critical to this vision are knowledge models called ontologies, which define a set of concepts and formalize the relations between them. Ontologies have been developed to manage and exploit the large and rapidly growing volume of information in biomedical domains. In diagnostic radiology, lists of differential diagnoses of imaging observations, called gamuts, provide an important source of knowledge. The Radiology Gamuts Ontology (RGO) is a formal knowledge model of differential diagnoses in radiology that includes 1674 differential diagnoses, 19,017 terms, and 52,976 links between terms. Its knowledge is used to provide an interactive, freely available online reference of radiology gamuts ( www.gamuts.net ). A Web service allows its content to be discovered and consumed by other information systems. The RGO integrates radiologic knowledge with other biomedical ontologies as part of the Semantic Web. PMID:24428295

  9. Orthopaedic radiology

    SciTech Connect

    Park, W.M.; Hughes, S.P.F.

    1987-01-01

    This book is an account of the principles of modern diagnostic imaging techniques and their applications in orthopedics. The aim is to show radiology as a dynamic subject. Orthopaedic Radiology is divided into two sections with the first part focusing on the principles of diagnostic imaging and interpretation and the second applying this information to practical clinical problems.

  10. Skeletal radiology

    SciTech Connect

    Bowerman, J.W.

    1982-01-01

    The main emphasis of the chapter on skeletal radiology is CAT scanning and its use in the diagnosis of neoplasms. Other topics that are discussed include infections, arthritis, trauma, and metabolic and endocrine diseases as they relate to skeletal radiology. (KRM)

  11. A study of numerical methods for hyperbolic conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Leveque, R. J.; Yee, H. C.

    1988-01-01

    The proper modeling of nonequilibrium gas dynamics is required in certain regimes of hypersonic flow. For inviscid flow this gives a system of conservation laws coupled with source terms representing the chemistry. Often a wide range of time scales is present in the problem, leading to numerical difficulties as in stiff systems of ordinary differential equations. Stability can be achieved by using implicit methods, but other numerical difficulties are observed. The behavior of typical numerical methods on a simple advection equation with a parameter-dependent source term was studied. Two approaches to incorporate the source term were utilized: MacCormack type predictor-corrector methods with flux limiters, and splitting methods in which the fluid dynamics and chemistry are handled in separate steps. Various comparisons over a wide range of parameter values were made. In the stiff case where the solution contains discontinuities, incorrect numerical propagation speeds are observed with all of the methods considered. This phenomenon is studied and explained.

  12. Analysis of accident sequences and source terms at treatment and storage facilities for waste generated by US Department of Energy waste management operations

    SciTech Connect

    Mueller, C.; Nabelssi, B.; Roglans-Ribas, J.; Folga, S.; Policastro, A.; Freeman, W.; Jackson, R.; Mishima, J.; Turner, S.

    1996-12-01

    This report documents the methodology, computational framework, and results of facility accident analyses performed for the US Department of Energy (DOE) Waste Management Programmatic Environmental Impact Statement (WM PEIS). The accident sequences potentially important to human health risk are specified, their frequencies assessed, and the resultant radiological and chemical source terms evaluated. A personal-computer-based computational framework and database have been developed that provide these results as input to the WM PEIS for the calculation of human health risk impacts. The WM PEIS addresses management of five waste streams in the DOE complex: low-level waste (LLW), hazardous waste (HW), high-level waste (HLW), low-level mixed waste (LLMW), and transuranic waste (TRUW). Currently projected waste generation rates, storage inventories, and treatment process throughputs have been calculated for each of the waste streams. This report summarizes the accident analyses and aggregates the key results for each of the waste streams. Source terms are estimated, and results are presented for each of the major DOE sites and facilities by WM PEIS alternative for each waste stream. Key assumptions in the development of the source terms are identified. The appendices identify the potential atmospheric release of each toxic chemical or radionuclide for each accident scenario studied. They also discuss specific accident analysis data and guidance used or consulted in this report.

  13. A study of numerical methods for hyperbolic conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Leveque, R. J.; Yee, H. C.

    1990-01-01

    In the present study of the behavior of typical numerical methods in the case of a model advection equation having a parameter-dependent source term, two approaches to the incorporation of the source terms are used: MacCormack-type predictor-corrector methods with flux limiters, and splitting methods in which the fluid dynamics and chemistry are handled in separate steps. The latter are found to perform slightly better. The model scalar equation is used to show that the incorrectness of the propagation speeds of discontinuities observed in the stiff case is due to the introduction of nonequilibrium values through numerical dissipation in the advection step.

  14. Source-term characterisation and solid speciation of plutonium at the Semipalatinsk NTS, Kazakhstan.

    PubMed

    Nápoles, H Jiménez; León Vintró, L; Mitchell, P I; Omarova, A; Burkitbayev, M; Priest, N D; Artemyev, O; Lukashenko, S

    2004-01-01

    New data on the concentrations of key fission/activation products and transuranium nuclides in samples of soil and water from the Semipalatinsk Nuclear Test Site are presented and interpreted. Sampling was carried out at Ground Zero, Lake Balapan, the Tel'kem craters and reference locations within the test site boundary well removed from localised sources. Radionuclide ratios have been used to characterise the source term(s) at each of these sites. The geochemical partitioning of plutonium has also been examined and it is shown that the bulk of the plutonium contamination at most of the sites examined is in a highly refractory, non-labile form. PMID:15177366

  15. An Alternative Treatment of Trace Chemical Constituents in Calculated Chemical Source Terms for Hanford Tank Farms Safety Analsyes

    SciTech Connect

    Huckaby, James L.

    2006-09-26

    Hanford Site high-level radioactive waste tank accident analyses require chemical waste toxicity source terms to assess potential accident consequences. Recent reviews of the current methodology used to generate source terms and the need to periodically update the sources terms has brought scrutiny to the manner in which trace waste constituents are included in the source terms. This report examines the importance of trace constituents to the chemical waste source terms, which are calculated as sums of fractions (SOFs), and recommends three changes to the manner in which trace constituents are included in the calculation SOFs.

  16. Handbook of radiologic procedures

    SciTech Connect

    Hedgcock, M.

    1986-01-01

    This book is organized around radiologic procedures with each discussed from the points of view of: indications, contraindications, materials, method of procedures and complications. Covered in this book are: emergency radiology chest radiology, bone radiology, gastrointestinal radiology, GU radiology, pediatric radiology, computerized tomography, neuroradiology, visceral and peripheral angiography, cardiovascular radiology, nuclear medicine, lymphangiography, and mammography.

  17. Using Reactive Transport Modeling to Evaluate the Source Term at Yucca Mountain

    SciTech Connect

    Y. Chen

    2001-12-19

    The conventional approach of source-term evaluation for performance assessment of nuclear waste repositories uses speciation-solubility modeling tools and assumes pure phases of radioelements control their solubility. This assumption may not reflect reality, as most radioelements (except for U) may not form their own pure phases. As a result, solubility limits predicted using the conventional approach are several orders of magnitude higher then the concentrations of radioelements measured in spent fuel dissolution experiments. This paper presents the author's attempt of using a non-conventional approach to evaluate source term of radionuclide release for Yucca Mountain. Based on the general reactive-transport code AREST-CT, a model for spent fuel dissolution and secondary phase precipitation has been constructed. The model accounts for both equilibrium and kinetic reactions. Its predictions have been compared against laboratory experiments and natural analogues. It is found that without calibrations, the simulated results match laboratory and field observations very well in many aspects. More important is the fact that no contradictions between them have been found. This provides confidence in the predictive power of the model. Based on the concept of Np incorporated into uranyl minerals, the model not only predicts a lower Np source-term than that given by conventional Np solubility models, but also produces results which are consistent with laboratory measurements and observations. Moreover, two hypotheses, whether Np enters tertiary uranyl minerals or not, have been tested by comparing model predictions against laboratory observations, the results favor the former. It is concluded that this non-conventional approach of source term evaluation not only eliminates over-conservatism in conventional solubility approach to some extent, but also gives a realistic representation of the system of interest, which is a prerequisite for truly understanding the long-term

  18. Long-term variability in bright hard X-ray sources: 5+ years of BATSE data

    NASA Technical Reports Server (NTRS)

    Robinson, C. R.; Harmon, B. A.; McCollough, M. L.; Paciesas, W. S.; Sahi, M.; Scott, D. M.; Wilson, C. A.; Zhang, S. N.; Deal, K. J.

    1997-01-01

    The operation of the Compton Gamma Ray Observatory (CGRO)/burst and transient source experiment (BATSE) continues to provide data for inclusion into a data base for the analysis of long term variability in bright, hard X-ray sources. The all-sky capability of BATSE provides up to 30 flux measurements/day for each source. The long baseline and the various rising and setting occultation flux measurements allow searches for periodic and quasi-periodic signals with periods of between several hours to hundreds of days to be conducted. The preliminary results from an analysis of the hard X-ray variability in 24 of the brightest BATSE sources are presented. Power density spectra are computed for each source and profiles are presented of the hard X-ray orbital modulations in some X-ray binaries, together with amplitude modulations and variations in outburst durations and intensities in recurrent X-ray transients.

  19. Fission product source term research at Oak Ridge National Laboratory. [PWR; BWR

    SciTech Connect

    Malinauskas, A.P.

    1985-01-01

    The purpose of this work is to describe some of the research being performed at ORNL in support of the effort to describe, as realistically as possible, fission product source terms for nuclear reactor accidents. In order to make this presentation manageable, only those studies directly concerned with fission product behavior, as opposed to thermal hydraulics, accident sequence progression, etc., will be discussed.

  20. Enhancement of the source term algorithm for emergency response at the Savannah River Site

    SciTech Connect

    Simpkins, A.A.; O`Kula, K.R.; Taylor, R.P.; Kearnaghan, G.P.

    1992-12-31

    The purpose of this work is to use the results of the Savannah River Site K-Reactor Probabilistic Safety Assessment to determine the accident sequences and source terms for beyond design basis accidents. Additionally, the methodology necessary to allow the Reactor Accident Program to incorporate this information is to be discussed.

  1. Enhancement of the source term algorithm for emergency response at the Savannah River Site

    SciTech Connect

    Simpkins, A.A.; O'Kula, K.R.; Taylor, R.P.; Kearnaghan, G.P.

    1992-01-01

    The purpose of this work is to use the results of the Savannah River Site K-Reactor Probabilistic Safety Assessment to determine the accident sequences and source terms for beyond design basis accidents. Additionally, the methodology necessary to allow the Reactor Accident Program to incorporate this information is to be discussed.

  2. Short-Term Memory Stages in Sign vs. Speech: The Source of the Serial Span Discrepancy

    ERIC Educational Resources Information Center

    Hall, Matthew L.; Bavelier, Daphne

    2011-01-01

    Speakers generally outperform signers when asked to recall a list of unrelated verbal items. This phenomenon is well established, but its source has remained unclear. In this study, we evaluate the relative contribution of the three main processing stages of short-term memory--perception, encoding, and recall--in this effect. The present study…

  3. Laboratory experiments designed to provide limits on the radionuclide source term for the NNWSI Project

    SciTech Connect

    Oversby, V.M.; McCright, R.D.

    1984-11-01

    The Nevada Nuclear Waste Storage Investigations Project is investigating the suitability of the tuffaceous rocks at Yucca Mountain Nevada for potential use as a high-level nuclear waste repository. The horizon under investigation lies above the water table, and therefore offers a setting that differs substantially from other potential repository sites. The unsaturated zone environment allows a simple, but effective, waste package design. The source term for radionuclide release from the waste package will be based on laboratory experiments that determine the corrosion rates and mechanisms for the metal container and the dissolution rate of the waste form under expected long term conditions. This paper describes the present status of laboratory results and outlines the approach to be used in combining the data to develop a realistic source term for release of radionuclides from the waste package. 16 refs., 3 figs., 1 tab.

  4. Severe accident source term characteristics for selected Peach Bottom sequences predicted by the MELCOR Code

    SciTech Connect

    Carbajo, J.J.

    1993-09-01

    The purpose of this report is to compare in-containment source terms developed for NUREG-1159, which used the Source Term Code Package (STCP), with those generated by MELCOR to identify significant differences. For this comparison, two short-term depressurized station blackout sequences (with a dry cavity and with a flooded cavity) and a Loss-of-Coolant Accident (LOCA) concurrent with complete loss of the Emergency Core Cooling System (ECCS) were analyzed for the Peach Bottom Atomic Power Station (a BWR-4 with a Mark I containment). The results indicate that for the sequences analyzed, the two codes predict similar total in-containment release fractions for each of the element groups. However, the MELCOR/CORBH Package predicts significantly longer times for vessel failure and reduced energy of the released material for the station blackout sequences (when compared to the STCP results). MELCOR also calculated smaller releases into the environment than STCP for the station blackout sequences.

  5. Solid angle subtended by a cylindrical detector at a point source in terms of elliptic integrals

    NASA Astrophysics Data System (ADS)

    Prata, M. J.

    2003-07-01

    The solid angle subtended by a right circular cylinder at a point source located at an arbitrary position generally consists of a sum of two terms: that defined by the cylindrical surface (Ω cyl) and the other by either of the end circles (Ω circ) . We derive an expression for Ω cyl in terms of elliptic integrals of the first and third kinds and give similar expressions for Ω circ using integrals of the first and second kinds. These latter can be used alternatively to an expression also in terms of elliptic integrals, due to Philip A. Macklin and included as a footnote in Masket (Rev. Sci. Instrum. 28 (3) (1957) 191). The solid angle subtended by the whole cylinder when the source is located at an arbitrary location can then be calculated using elliptic integrals.

  6. The Chernobyl accident as a source of new radiological knowledge: implications for Fukushima rehabilitation and research programmes.

    PubMed

    Balonov, Mikhail

    2013-03-01

    The accident at the Chernobyl nuclear power plant in Ukraine in 1986 caused a huge release of radionuclides over large areas of Europe. During large scale activities focused on overcoming of its negative consequences for public health, various research programmes in radioecology, dosimetry and radiation medicine were conducted. New knowledge was applied internationally in substantial updating of radiation protection systems for emergency and existing situations of human exposure, for improvement of emergency preparedness and response. Radioecological and dosimetry models were significantly improved and validated with numerous measurement data, guidance on environmental countermeasures and monitoring elaborated and tested.New radiological knowledge can be of use in the planning and implementation of rehabilitation programmes in Japan following the Fukushima nuclear accident. In particular, the following activity areas would benefit from application of the Chernobyl experience: strategy of rehabilitation, and technology of settlement decontamination and of countermeasures applied in agriculture and forestry. The Chernobyl experience could be very helpful in planning research activities initiated by the Fukushima radionuclide fallout, i.e. environmental transfer of radionuclides, effectiveness of site-specific countermeasures, nationwide dose assessment, health effect studies, etc. PMID:23295495

  7. Coarse Grid Modeling of Turbine Film Cooling Flows Using Volumetric Source Terms

    NASA Technical Reports Server (NTRS)

    Heidmann, James D.; Hunter, Scott D.

    2001-01-01

    The recent trend in numerical modeling of turbine film cooling flows has been toward higher fidelity grids and more complex geometries. This trend has been enabled by the rapid increase in computing power available to researchers. However, the turbine design community requires fast turnaround time in its design computations, rendering these comprehensive simulations ineffective in the design cycle. The present study describes a methodology for implementing a volumetric source term distribution in a coarse grid calculation that can model the small-scale and three-dimensional effects present in turbine film cooling flows. This model could be implemented in turbine design codes or in multistage turbomachinery codes such as APNASA, where the computational grid size may be larger than the film hole size. Detailed computations of a single row of 35 deg round holes on a flat plate have been obtained for blowing ratios of 0.5, 0.8, and 1.0, and density ratios of 1.0 and 2.0 using a multiblock grid system to resolve the flows on both sides of the plate as well as inside the hole itself. These detailed flow fields were spatially averaged to generate a field of volumetric source terms for each conservative flow variable. Solutions were also obtained using three coarse grids having streamwise and spanwise grid spacings of 3d, 1d, and d/3. These coarse grid solutions used the integrated hole exit mass, momentum, energy, and turbulence quantities from the detailed solutions as volumetric source terms. It is shown that a uniform source term addition over a distance from the wall on the order of the hole diameter is able to predict adiabatic film effectiveness better than a near-wall source term model, while strictly enforcing correct values of integrated boundary layer quantities.

  8. Low-level radioactive waste source terms for the 1992 integrated data base

    SciTech Connect

    Loghry, S L; Kibbey, A H; Godbee, H W; Icenhour, A S; DePaoli, S M

    1995-01-01

    This technical manual presents updated generic source terms (i.e., unitized amounts and radionuclide compositions) which have been developed for use in the Integrated Data Base (IDB) Program of the U.S. Department of Energy (DOE). These source terms were used in the IDB annual report, Integrated Data Base for 1992: Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics, DOE/RW-0006, Rev. 8, October 1992. They are useful as a basis for projecting future amounts (volume and radioactivity) of low-level radioactive waste (LLW) shipped for disposal at commercial burial grounds or sent for storage at DOE solid-waste sites. Commercial fuel cycle LLW categories include boiling-water reactor, pressurized-water reactor, fuel fabrication, and uranium hexafluoride (UF{sub 6}) conversion. Commercial nonfuel cycle LLW includes institutional/industrial (I/I) waste. The LLW from DOE operations is category as uranium/thorium fission product, induced activity, tritium, alpha, and {open_quotes}other{close_quotes}. Fuel cycle commercial LLW source terms are normalized on the basis of net electrical output [MW(e)-year], except for UF{sub 6} conversion, which is normalized on the basis of heavy metal requirement [metric tons of initial heavy metal ]. The nonfuel cycle commercial LLW source term is normalized on the basis of volume (cubic meters) and radioactivity (curies) for each subclass within the I/I category. The DOE LLW is normalized in a manner similar to that for commercial I/I waste. The revised source terms are based on the best available historical data through 1992.

  9. Fukushima Daiichi reactor source term attribution using cesium isotope ratios from contaminated environmental samples

    DOE PAGESBeta

    Snow, Mathew S.; Snyder, Darin C.; Delmore, James E.

    2016-01-18

    Source term attribution of environmental contamination following the Fukushima Daiichi Nuclear Power Plant (FDNPP) disaster is complicated by a large number of possible similar emission source terms (e.g. FDNPP reactor cores 1–3 and spent fuel ponds 1–4). Cesium isotopic analyses can be utilized to discriminate between environmental contamination from different FDNPP source terms and, if samples are sufficiently temporally resolved, potentially provide insights into the extent of reactor core damage at a given time. Rice, soil, mushroom, and soybean samples taken 100–250 km from the FDNPP site were dissolved using microwave digestion. Radiocesium was extracted and purified using two sequentialmore » ammonium molybdophosphate-polyacrylonitrile columns, following which 135Cs/137Cs isotope ratios were measured using thermal ionization mass spectrometry (TIMS). Results were compared with data reported previously from locations to the northwest of FDNPP and 30 km to the south of FDNPP. 135Cs/137Cs isotope ratios from samples 100–250 km to the southwest of the FDNPP site show a consistent value of 0.376 ± 0.008. 135Cs/137Cs versus 134Cs/137Cs correlation plots suggest that radiocesium to the southwest is derived from a mixture of FDNPP reactor cores 1, 2, and 3. Conclusions from the cesium isotopic data are in agreement with those derived independently based upon the event chronology combined with meteorological conditions at the time of the disaster. In conclusion, cesium isotopic analyses provide a powerful tool for source term discrimination of environmental radiocesium contamination at the FDNPP site. For higher precision source term attribution and forensic determination of the FDNPP core conditions based upon cesium, analyses of a larger number of samples from locations to the north and south of the FDNPP site (particularly time-resolved air filter samples) are needed. Published in 2016. This article is a U.S. Government work and is in the public domain

  10. Radiological Safety Handbook.

    ERIC Educational Resources Information Center

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    Written to be used concurrently with the U.S. Army's Radiological Safety Course, this publication discusses the causes, sources, and detection of nuclear radiation. In addition, the transportation and disposal of radioactive materials are covered. The report also deals with the safety precautions to be observed when working with lasers, microwave…

  11. Research Training in Radiology.

    ERIC Educational Resources Information Center

    National Inst. of General Medical Sciences (NIH), Bethesda, MD.

    Radiology today is a major clinical specialty of medicine in terms of the number and complexity of patient examinations, and the financial resources, physician manpower, and supporting personnel required for performing its functions. It reached its present status because it provides accurate methods of diagnosis for so many diseases. However, this…

  12. A Systematic Search for Short-term Variability of EGRET Sources

    NASA Technical Reports Server (NTRS)

    Wallace, P. M.; Griffis, N. J.; Bertsch, D. L.; Hartman, R. C.; Thompson, D. J.; Kniffen, D. A.; Bloom, S. D.

    2000-01-01

    The 3rd EGRET Catalog of High-energy Gamma-ray Sources contains 170 unidentified sources, and there is great interest in the nature of these sources. One means of determining source class is the study of flux variability on time scales of days; pulsars are believed to be stable on these time scales while blazers are known to be highly variable. In addition, previous work has demonstrated that 3EG J0241-6103 and 3EG J1837-0606 are candidates for a new gamma-ray source class. These sources near the Galactic plane display transient behavior but cannot be associated with any known blazers. Although, many instances of flaring AGN have been reported, the EGRET database has not been systematically searched for occurrences of short-timescale (approximately 1 day) variability. These considerations have led us to conduct a systematic search for short-term variability in EGRET data, covering all viewing periods through proposal cycle 4. Six 3EG catalog sources are reported here to display variability on short time scales; four of them are unidentified. In addition, three non-catalog variable sources are discussed.

  13. Algorithms and analytical solutions for rapidly approximating long-term dispersion from line and area sources

    NASA Astrophysics Data System (ADS)

    Barrett, Steven R. H.; Britter, Rex E.

    Predicting long-term mean pollutant concentrations in the vicinity of airports, roads and other industrial sources are frequently of concern in regulatory and public health contexts. Many emissions are represented geometrically as ground-level line or area sources. Well developed modelling tools such as AERMOD and ADMS are able to model dispersion from finite (i.e. non-point) sources with considerable accuracy, drawing upon an up-to-date understanding of boundary layer behaviour. Due to mathematical difficulties associated with line and area sources, computationally expensive numerical integration schemes have been developed. For example, some models decompose area sources into a large number of line sources orthogonal to the mean wind direction, for which an analytical (Gaussian) solution exists. Models also employ a time-series approach, which involves computing mean pollutant concentrations for every hour over one or more years of meteorological data. This can give rise to computer runtimes of several days for assessment of a site. While this may be acceptable for assessment of a single industrial complex, airport, etc., this level of computational cost precludes national or international policy assessments at the level of detail available with dispersion modelling. In this paper, we extend previous work [S.R.H. Barrett, R.E. Britter, 2008. Development of algorithms and approximations for rapid operational air quality modelling. Atmospheric Environment 42 (2008) 8105-8111] to line and area sources. We introduce approximations which allow for the development of new analytical solutions for long-term mean dispersion from line and area sources, based on hypergeometric functions. We describe how these solutions can be parameterized from a single point source run from an existing advanced dispersion model, thereby accounting for all processes modelled in the more costly algorithms. The parameterization method combined with the analytical solutions for long-term mean

  14. Search for correlated radio and optical events in long-term studies of extragalactic sources

    NASA Technical Reports Server (NTRS)

    Pomphrey, R. B.; Smith, A. G.; Leacock, R. J.; Olsson, C. N.; Scott, R. L.; Pollock, J. T.; Edwards, P.; Dent, W. A.

    1976-01-01

    For the first time, long-term records of radio and optical fluxes of a large sample of variable extragalactic sources have been assembled and compared, with linear cross-correlation analysis being used to reinforce the visual comparisons. Only in the case of the BL Lac object OJ 287 is the correlation between radio and optical records strong. In the majority of cases there is no evidence of significant correlation, although nine sources show limited or weak evidence of correlation. The results do not support naive extrapolation of the expanding source model. The general absence of strong correlation between the radio and optical regions has important implications for the energetics of events occurring in such sources.

  15. Accident source terms for Light-Water Nuclear Power Plants. Final report

    SciTech Connect

    Soffer, L.; Burson, S.B.; Ferrell, C.M.; Lee, R.Y.; Ridgely, J.N.

    1995-02-01

    In 1962 tile US Atomic Energy Commission published TID-14844, ``Calculation of Distance Factors for Power and Test Reactors`` which specified a release of fission products from the core to the reactor containment for a postulated accident involving ``substantial meltdown of the core``. This ``source term``, tile basis for tile NRC`s Regulatory Guides 1.3 and 1.4, has been used to determine compliance with tile NRC`s reactor site criteria, 10 CFR Part 100, and to evaluate other important plant performance requirements. During the past 30 years substantial additional information on fission product releases has been developed based on significant severe accident research. This document utilizes this research by providing more realistic estimates of the ``source term`` release into containment, in terms of timing, nuclide types, quantities and chemical form, given a severe core-melt accident. This revised ``source term`` is to be applied to the design of future light water reactors (LWRs). Current LWR licensees may voluntarily propose applications based upon it.

  16. Groundwater modeling of source terms and contaminant plumes for DOE low-level waste performance assessments

    SciTech Connect

    McDowell-Boyer, L.M.; Wilson, J.E.

    1994-06-01

    Under US Department of Energy (DOE) Order 5820.2A, all sites within the DOE complex must analyze the performance of planned radioactive waste disposal facilities before disposal takes place through the radiological performance assessment process. These assessments consider both exposures to the public from radionuclides potentially released from disposal facilities and protection of groundwater resources. Compliance with requirements for groundwater protection is often the most difficult to demonstrate as these requirements are generally more restrictive than those for other pathways. Modeling of subsurface unsaturated and saturated flow and transport was conducted for two such assessments for the Savannah River site. The computer code PORFLOW was used to evaluate release and transport of radionuclides from different types of disposal unit configurations: vault disposal and trench disposal. The effectiveness of engineered barriers was evaluated in terms of compliance with groundwater protection requirements. The findings suggest that, due to the limited lifetime of engineered barriers, overdesign of facilities for long-lived radionuclides is likely to occur if compliance must be realized for thousands of years.

  17. Radiological assessment. A textbook on environmental dose analysis

    SciTech Connect

    Till, J.E.; Meyer, H.R.

    1983-09-01

    Radiological assessment is the quantitative process of estimating the consequences to humans resulting from the release of radionuclides to the biosphere. It is a multidisciplinary subject requiring the expertise of a number of individuals in order to predict source terms, describe environmental transport, calculate internal and external dose, and extrapolate dose to health effects. Up to this time there has been available no comprehensive book describing, on a uniform and comprehensive level, the techniques and models used in radiological assessment. Radiological Assessment is based on material presented at the 1980 Health Physics Society Summer School held in Seattle, Washington. The material has been expanded and edited to make it comprehensive in scope and useful as a text. Topics covered include (1) source terms for nuclear facilities and Medical and Industrial sites; (2) transport of radionuclides in the atmosphere; (3) transport of radionuclides in surface waters; (4) transport of radionuclides in groundwater; (5) terrestrial and aquatic food chain pathways; (6) reference man; a system for internal dose calculations; (7) internal dosimetry; (8) external dosimetry; (9) models for special-case radionuclides; (10) calculation of health effects in irradiated populations; (11) evaluation of uncertainties in environmental radiological assessment models; (12) regulatory standards for environmental releases of radionuclides; (13) development of computer codes for radiological assessment; and (14) assessment of accidental releases of radionuclides.

  18. The radiological assessment system for consequence analysis - RASCAL

    SciTech Connect

    Sjoreen, A.L.; Ramsdell, J.V.; Athey, G.F.

    1996-04-01

    The Radiological Assessment System for Consequence Analysis, Version 2.1 (RASCAL 2.1) has been developed for use during a response to radiological emergencies. The model estimates doses for comparison with U.S. Environmental Protection Agency (EPA) Protective Action Guides (PAGs) and thresholds for acute health effects. RASCAL was designed to be used by U.S. Nuclear Regulatory Commission (NRC) personnel who report to the site of a nuclear accident to conduct an independent evaluation of dose and consequence projections and personnel who conduct training and drills on emergency responses. It allows consideration of the dominant aspects of the source term, transport, dose, and consequences. RASCAL consists of three computational tools: ST-DOSE, FM-DOSE, and DECAY. ST-DOSE computes source term, atmospheric transport, and dose to man from accidental airborne releases of radionuclides. The source-term calculations are appropriate for accidents at U.S. power reactors. FM-DOSE computes doses from environmental concentrations of radionuclides in the air and on the ground. DECAY computes radiological decay and daughter in-growth. RASCAL 2.1 is a DOS application that can be run under Windows 3.1 and 95. RASCAL has been the starting point for other accident consequence models, notably INTERRAS, an international version of RASCAL, and HASCAL, an expansion of RASCAL that will model radiological, biological, and chemical accidents.

  19. A Systematic Search for Short-term Variability of EGRET Sources

    NASA Technical Reports Server (NTRS)

    Wallace, P. M.; Bertsch, D. L.; Bloom, S. D.; Griffis, N. J.; Hunter, S. D.; Kniffen, D. A.; Thompson, D. J.

    1999-01-01

    The 3rd EGRET Catalog contains 170 unidentified high-energy (E>100 MeV) gamma-ray sources, and there is great interest in the nature of these sources. One means of determining sources class is the study of flux variability on time scales of days; pulsars are believed to be stable on these scales while blazars are known to be highly variable. In addition, previous work has led to the discovery of 2CG 135+01 and GRO J1838-04, candidates for a new high-energy gamma-ray source class. These sources display transient behavior but cannot be associated with any known blazars. These considerations have led us to conduct a systematic search for short-term variability in EGRET data, covering all viewing periods through cycle 4. Three unidentified sources show some evidence of variability on short time scales; the source displaying the most convincing variability, 3EG J2006-2321, is not easily identified as a blazar.

  20. Understanding the electrical behavior of the action potential in terms of elementary electrical sources.

    PubMed

    Rodriguez-Falces, Javier

    2015-03-01

    A concept of major importance in human electrophysiology studies is the process by which activation of an excitable cell results in a rapid rise and fall of the electrical membrane potential, the so-called action potential. Hodgkin and Huxley proposed a model to explain the ionic mechanisms underlying the formation of action potentials. However, this model is unsuitably complex for teaching purposes. In addition, the Hodgkin and Huxley approach describes the shape of the action potential only in terms of ionic currents, i.e., it is unable to explain the electrical significance of the action potential or describe the electrical field arising from this source using basic concepts of electromagnetic theory. The goal of the present report was to propose a new model to describe the electrical behaviour of the action potential in terms of elementary electrical sources (in particular, dipoles). The efficacy of this model was tested through a closed-book written exam. The proposed model increased the ability of students to appreciate the distributed character of the action potential and also to recognize that this source spreads out along the fiber as function of space. In addition, the new approach allowed students to realize that the amplitude and sign of the extracellular electrical potential arising from the action potential are determined by the spatial derivative of this intracellular source. The proposed model, which incorporates intuitive graphical representations, has improved students' understanding of the electrical potentials generated by bioelectrical sources and has heightened their interest in bioelectricity. PMID:25727465

  1. Unclassified Sources Term and Radionuclide Data for Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nevada, Revision 2

    SciTech Connect

    Peter Martian

    2009-08-01

    This report documents the evaluation of the information and data available on the unclassified source term and radionuclide contamination for CAU 97: Yucca Flat/Climax Mine. The total residual inventory of radionuclides associated with one or more tests is known as the radiologic source term (RST). The RST is comprised of radionuclides in water, glass, or other phases or mineralogic forms. The hydrologic source term (HST) of an underground nuclear test is the portion of the total RST that is released into the groundwater over time following the test. In this report, the HST represents radionuclide release some time after the explosion and does not include the rapidly evolving mechanical, thermal, and chemical processes during the explosion. The CAU 97: Yucca Flat/Climax Mine has many more detonations and a wider variety of settings to consider compared to other CAUs. For instance, the source term analysis and evaluation performed for CAUs 101 and 102: Central and Western Pahute Mesa and CAU 98: Frenchman Flat did not consider vadose zone attenuation because many detonations were located near or below the water table. However, the large number of Yucca Flat/Climax Mine tests and the location of many tests above the water table warrant a more robust analysis of the unsaturated zone. The purpose of this report is to develop and document conceptual models of the Yucca Flat/Climax Mine HST for use in implementing source terms for the Yucca Flat/Climax Mine models. This document presents future plans to incorporate the radionuclide attenuation mechanisms due to unsaturated/multiphase flow and transport within the Yucca Flat CAU scale modeling. The important processes that influence radionuclide migration for the unsaturated and saturated tests in alluvial, volcanic, and carbonate settings are identified. Many different flow and transport models developed by Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), including original

  2. Source terms for analysis of accidents at a high level waste repository

    SciTech Connect

    Mubayi, V.; Davis, R.E.; Youngblood, R.

    1989-01-01

    This paper describes an approach to identifying source terms from possible accidents during the preclosure phase of a high-level nuclear waste repository. A review of the literature on repository safety analyses indicated that source term estimation is in a preliminary stage, largely based on judgement-based scoping analyses. The approach developed here was to partition the accident space into domains defined by certain threshold values of temperature and impact energy density which may arise in potential accidents and specify release fractions of various radionuclides, present in the waste form, in each domain. Along with a more quantitative understanding of accident phenomenology, this approach should help in achieving a clearer perspective on scenarios important to preclosure safety assessments of geologic repositories. 18 refs., 3 tabs.

  3. On the application of subcell resolution to conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Chang, Shih-Hung

    1989-01-01

    LeVeque and Yee recently investigated a one-dimensional scalar conservation law with stiff source terms modeling the reacting flow problems and discovered that for the very stiff case most of the current finite difference methods developed for non-reacting flows would produce wrong solutions when there is a propagating discontinuity. A numerical scheme, essentially nonoscillatory/subcell resolution - characteristic direction (ENO/SRCD), is proposed for solving conservation laws with stiff source terms. This scheme is a modification of Harten's ENO scheme with subcell resolution, ENO/SR. The locations of the discontinuities and the characteristic directions are essential in the design. Strang's time-splitting method is used and time evolutions are done by advancing along the characteristics. Numerical experiment using this scheme shows excellent results on the model problem of LeVeque and Yee. Comparisons of the results of ENO, ENO/SR, and ENO/SRCD are also presented.

  4. Open reduction and internal fixation of extracapsular mandibular condyle fractures: a long-term clinical and radiological follow-up of 25 patients

    PubMed Central

    2014-01-01

    Background During the last 2 decades, many studies on the treatment of mandibular condyle fracture have been published. The incidence of mandibular condyle fractures is variable, ranging from 17.5% to 52% of all mandibular fractures. This retrospective study evaluated the long-term clinical and radiological outcomes after surgical treatment of 25 patients with a total of 26 extracapsular condyle fractures. Methods We used 2 types of surgical approaches, the retromandibular retroparotid or preauricular approach. Three kinds of rigid internal fixation plates were used—single plate, double plate, and trapezoidal plate. The following post-operative clinical parameters were evaluated: dental occlusion, facial nerve functionality, skin scarring, and temporomandibular joint functionality. All patients underwent post-operative orthopanoramic radiography and computed tomography. The patients were also monitored for complications such as Frey’s syndrome, infection, salivary fistula, plate fracture, and permanent paralysis of the facial nerve; the patient’s satisfaction was also recorded. Results Of the 25 patients, 80% showed occlusion recovery, 88% had no facial nerve injury, and 88% presented good surgical skin scarring. The patients showed early complete recovery of temporomandibular joint functionality and 72% of them were found to be asymptomatic. The postoperative radiographs of all patients indicated good recovery of the anatomical condylar region, and 80% of them had no postoperative complications. The average degree of patient satisfaction was 8.32 out of 10. Our results confirm that the technique of open reduction and internal fixation in association with postoperative functional rehabilitation therapy should be considered for treating patients with extracapsular condylar fractures. Conclusion The topic of condylar injury has generated more discussion and controversy than any other topic in the field of maxillofacial trauma. We confirm that open reduction and

  5. Implementation of New Turbulence Spectra in the Lighthill Analogy Source Terms

    NASA Technical Reports Server (NTRS)

    Woodruff, S. L.; Seiner, J. M.; Hussaini, M. Y.; Erlebacher, G.

    2000-01-01

    The industry-standard MGB approach to predicting the noise generated by a given aerodynamic flow field requires that the turbulence velocity correlation be specified so that the source terms in the Lighthill acoustic analogy may be computed. The velocity correlation traditionally used in MGB Computations is inconsistent with a number of basic qualitative properties of turbulent flows. In the present investigation the effect on noise prediction of using two alternative velocity correlations is examined.

  6. 2D and 3D potential flows with rotational source terms in turbomachines

    NASA Astrophysics Data System (ADS)

    Alkalai, K.; Leboeuf, F.

    A computational method capable of treating two- and three-dimensional potential flows is developed which includes blade effects and viscosity in source terms determined over the entire flowfield considered. Details of the mathematical and numerical formulations are given, and grid generation and density calculation are discussed. Preliminary results obtained with the codes developed here are then presented, and the possibility of applying the method to more complex flows is examined.

  7. Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences

    NASA Astrophysics Data System (ADS)

    Biri, S.; Kitagawa, A.; Muramatsu, M.; Drentje, A. G.; Rácz, R.; Yano, K.; Kato, Y.; Sasaki, N.; Takasugi, W.

    2014-02-01

    The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide band-width (17.1-18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1-18.5 GHz), and the effect of this frequency on the HCI-production rate was examined under several operation conditions. As an overall result, new beam records of highly charged argon, krypton, and xenon beams were obtained at the NIRS-HEC ion source by this high-power two-frequency operation mode.

  8. Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences

    SciTech Connect

    Biri, S.; Rácz, R.; Sasaki, N.; Takasugi, W.

    2014-02-15

    The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide band-width (17.1–18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1–18.5 GHz), and the effect of this frequency on the HCI-production rate was examined under several operation conditions. As an overall result, new beam records of highly charged argon, krypton, and xenon beams were obtained at the NIRS-HEC ion source by this high-power two-frequency operation mode.

  9. Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences.

    PubMed

    Biri, S; Kitagawa, A; Muramatsu, M; Drentje, A G; Rácz, R; Yano, K; Kato, Y; Sasaki, N; Takasugi, W

    2014-02-01

    The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide band-width (17.1-18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1-18.5 GHz), and the effect of this frequency on the HCI-production rate was examined under several operation conditions. As an overall result, new beam records of highly charged argon, krypton, and xenon beams were obtained at the NIRS-HEC ion source by this high-power two-frequency operation mode. PMID:24593510

  10. Balancing the source terms in a SPH model for solving the shallow water equations

    NASA Astrophysics Data System (ADS)

    Xia, Xilin; Liang, Qiuhua; Pastor, Manuel; Zou, Weilie; Zhuang, Yan-Feng

    2013-09-01

    A shallow flow generally features complex hydrodynamics induced by complicated domain topography and geometry. A numerical scheme with well-balanced flux and source term gradients is therefore essential before a shallow flow model can be applied to simulate real-world problems. The issue of source term balancing has been exhaustively investigated in grid-based numerical approaches, e.g. discontinuous Galerkin finite element methods and finite volume Godunov-type methods. In recent years, a relatively new computational method, smooth particle hydrodynamics (SPH), has started to gain popularity in solving the shallow water equations (SWEs). However, the well-balanced problem has not been fully investigated and resolved in the context of SPH. This work aims to discuss the well-balanced problem caused by a standard SPH discretization to the SWEs with slope source terms and derive a corrected SPH algorithm that is able to preserve the solution of lake at rest. In order to enhance the shock capturing capability of the resulting SPH model, the Monotone Upwind-centered Scheme for Conservation Laws (MUSCL) is also explored and applied to enable Riemann solver based artificial viscosity. The new SPH model is validated against several idealized benchmark tests and a real-world dam-break case and promising results are obtained.

  11. Schematic way to find solution of the outcoupled matter wave with a source term

    SciTech Connect

    Prayitno, T. B.

    2013-09-09

    We propose a schematic way to obtain solution of the outcoupled atom laser beam wave function in the presence of a source term where the beam is influenced by gravity. In this case, we only focus on the external potentials inside the region of Bose-Einstein condensate that are generated by electromagnetic source and gravity. Since the evolution of the atom laser beam can be portrayed through the ordinary Schrödinger equation with a source, we are allowed to express the general solution as the superposition of the homogeneous solution and particular solution. With the given external potentials and ansatz solutions, we attain that the obtained energy depends on the parameter constituting to the ratio between the longitudinal frequency and transverse frequency.

  12. Long-term outcome after whiplash injury. A 2-year follow-up considering features of injury mechanism and somatic, radiologic, and psychosocial findings.

    PubMed

    Radanov, B P; Sturzenegger, M; Di Stefano, G

    1995-09-01

    With the increased incidence of whiplash injury following the introduction of compulsory car seat belts, a large number of reports have dealt with the aftermath of this condition. Previous studies, however, focused on somatic symptoms on the one hand or considered only psychological or neuropsychological variables on the other hand, often in loosely defined or selected groups of patients. No study so far has analyzed the long-term outcome in a nonselected group of patients using a clear injury definition considering patient history; somatic, radiologic, and neuropsychological findings; and features of the injury mechanisms assessed soon after trauma and during follow-up. the present investigation was designed to assess these combined factors. According to a strict definition of whiplash injury, we assessed a consecutive nonselected sample of 117 patients with recent injury who had similar sociocultural and educational backgrounds. The patients had been in automobile crashes and were all equally covered by accident insurance according to the country-wide scheme. Initial examination was performed 7.2 +/- 4.2 days after trauma, and follow-up examinations 3, 6, 12, and 24 months later. At baseline, features of injury mechanism, subjective complaints, and different aspects of patient history were documented and cervical spine X rays performed. At all examinations patients underwent neurologic examination and cognitive and psychosocial factor assessment. At 2 years, patients were divided into symptomatic and asymptomatic groups and then compared with regard to the initial findings. In addition, symptomatic patients who were disabled at the 2-year follow-up examination and symptomatic patients not disabled (that is, they were able to work at the pretraumatic level) were compared regarding initial and 2-year findings. At 2 years, 18% of patients still had injury-related symptoms. With regard to baseline findings the following significant differences were found: Symptomatic

  13. Automated source term and wind parameter estimation for atmospheric transport and dispersion applications

    NASA Astrophysics Data System (ADS)

    Bieringer, Paul E.; Rodriguez, Luna M.; Vandenberghe, Francois; Hurst, Jonathan G.; Bieberbach, George; Sykes, Ian; Hannan, John R.; Zaragoza, Jake; Fry, Richard N.

    2015-12-01

    Accurate simulations of the atmospheric transport and dispersion (AT&D) of hazardous airborne materials rely heavily on the source term parameters necessary to characterize the initial release and meteorological conditions that drive the downwind dispersion. In many cases the source parameters are not known and consequently based on rudimentary assumptions. This is particularly true of accidental releases and the intentional releases associated with terrorist incidents. When available, meteorological observations are often not representative of the conditions at the location of the release and the use of these non-representative meteorological conditions can result in significant errors in the hazard assessments downwind of the sensors, even when the other source parameters are accurately characterized. Here, we describe a computationally efficient methodology to characterize both the release source parameters and the low-level winds (eg. winds near the surface) required to produce a refined downwind hazard. This methodology, known as the Variational Iterative Refinement Source Term Estimation (STE) Algorithm (VIRSA), consists of a combination of modeling systems. These systems include a back-trajectory based source inversion method, a forward Gaussian puff dispersion model, a variational refinement algorithm that uses both a simple forward AT&D model that is a surrogate for the more complex Gaussian puff model and a formal adjoint of this surrogate model. The back-trajectory based method is used to calculate a "first guess" source estimate based on the available observations of the airborne contaminant plume and atmospheric conditions. The variational refinement algorithm is then used to iteratively refine the first guess STE parameters and meteorological variables. The algorithm has been evaluated across a wide range of scenarios of varying complexity. It has been shown to improve the source parameters for location by several hundred percent (normalized by the

  14. Natural Language Processing in Radiology: A Systematic Review.

    PubMed

    Pons, Ewoud; Braun, Loes M M; Hunink, M G Myriam; Kors, Jan A

    2016-05-01

    Radiological reporting has generated large quantities of digital content within the electronic health record, which is potentially a valuable source of information for improving clinical care and supporting research. Although radiology reports are stored for communication and documentation of diagnostic imaging, harnessing their potential requires efficient and automated information extraction: they exist mainly as free-text clinical narrative, from which it is a major challenge to obtain structured data. Natural language processing (NLP) provides techniques that aid the conversion of text into a structured representation, and thus enables computers to derive meaning from human (ie, natural language) input. Used on radiology reports, NLP techniques enable automatic identification and extraction of information. By exploring the various purposes for their use, this review examines how radiology benefits from NLP. A systematic literature search identified 67 relevant publications describing NLP methods that support practical applications in radiology. This review takes a close look at the individual studies in terms of tasks (ie, the extracted information), the NLP methodology and tools used, and their application purpose and performance results. Additionally, limitations, future challenges, and requirements for advancing NLP in radiology will be discussed. (©) RSNA, 2016 Online supplemental material is available for this article. PMID:27089187

  15. Review of uncertainty sources affecting the long-term predictions of space debris evolutionary models

    NASA Astrophysics Data System (ADS)

    Dolado-Perez, J. C.; Pardini, Carmen; Anselmo, Luciano

    2015-08-01

    Since the launch of Sputnik-I in 1957, the amount of space debris in Earth's orbit has increased continuously. Historically, besides abandoned intact objects (spacecraft and orbital stages), the primary sources of space debris in Earth's orbit were (i) accidental and intentional break-ups which produced long-lasting debris and (ii) debris released intentionally during the operation of launch vehicle orbital stages and spacecraft. In the future, fragments generated by collisions are expected to become a significant source as well. In this context, and from a purely mathematical point of view, the orbital debris population in Low Earth Orbit (LEO) should be intrinsically unstable, due to the physics of mutual collisions and the relative ineffectiveness of natural sink mechanisms above~700 km. Therefore, the real question should not be "if", but "when" the exponential growth of the space debris population is supposed to start. From a practical point of view, and in order to answer the previous question, since the end of the 1980's several sophisticated long-term debris evolutionary models have been developed. Unfortunately, the predictions performed with such models, in particular beyond a few decades, are affected by considerable uncertainty. Such uncertainty comes from a relative important number of variables that being either under the partial control or completely out of the control of modellers, introduce a variability on the long-term simulation of the space debris population which cannot be captured with standard Monte Carlo statistics. The objective of this paper is to present and discuss many of the uncertainty sources affecting the long-term predictions done with evolutionary models, in order to serve as a roadmap for the uncertainty and the statistical robustness analysis of the long-term evolution of the space debris population.

  16. Preliminary study on the radiological and physicochemical quality of the Umgeni Water catchments and drinking water sources in KwaZulu-Natal, South Africa.

    PubMed

    Manickum, T; John, W; Terry, S; Hodgson, K

    2014-11-01

    Raw and potable water sample sources, from the Umgeni Water catchment areas (rivers, dams, boreholes) in central KwaZulu-Natal (South Africa), were screened for Uranium concentration and alpha and beta radioactivity. Test methods used were gas flow proportional counting for alpha-beta radioactivity, and kinetic phosphorescence analysis (KPA), for Uranium. The uranium levels (median = 0.525 μg/L, range = <0.050-5.010) were well below the international World Health Organization (WHO) (2011) guideline for drinking-water quality (≤15 μg/L). The corresponding alpha and beta radioactivity was ≤0.5 Bq/L (median = 0.084, Interquartile Range (IR) = 0.038, range = 0.018-0.094), and ≤1.0 Bq/L (median = 0.114, IR = 0.096, range = 0.024-0.734), respectively, in compliance with the international WHO limits. For uranium radionuclide, the average dose level, at uranium level of ±0.525 μg/L, was 0.06 μSv/a, which complies with the WHO reference dose level for drinking water (<0.1 mSv/a). There was a distinct trend of cluster of relatively higher Uranium levels of some sources that were found to be associated with the geology/geography and groundwater sources. Overall, the radiological water quality classification, with respect to WHO, is "Blue" - ideal; additional physicochemical analyses indicated good water quality. The analytical test methods employed were found to be suitable for preliminary screening for potential radioactive "hot spots". The observed Uranium levels, and the alpha/beta radioactivity, indicate contribution largely from Naturally Occurring Radioactive Material (NORM), with no significant health risk to humans, or to the environment. PMID:25151527

  17. Long-Term Safe Storage and Disposal of Spent Sealed Radioactive Sources in Borehole Type Repositories

    SciTech Connect

    Ojovan, M. I.; Dmitriev, S. A.; Sobolev, I. A.

    2003-02-26

    Russian Federation has the leading experience in applying borehole storage/disposal method for SRS. A new immobilization technology for sources being disposed of in underground repositories was mastered by 1986 and since then it is used in the country. This method uses all advantages of borehole type repositories supplementing them with metal encapsulation of sources. Sources being uniformly allocated in the volume of underground vessel are fixed in the metal block hence ensuring long-term safety. The dissipation of radiogenic heat from SRS is considerably improved, radiation fields are reduced, and direct contact of sources to an environment is completely eliminated. The capacity of a typical borehole storage/disposal facility is increased almost 6 times applying metal immobilization. That has made new technology extremely favourable economically. The metal immobilization of SRS is considered as an option in Belarus and Ukraine as well as Bulgaria. Immobilization of sources in metal matrices can be a real solution for retrieval of SRS from inadequate repositories.

  18. Interventional radiology

    SciTech Connect

    Castaneda-Zuniga, W.R.

    1987-01-01

    This reference gives a step-by-step presentation of the elements of interventional radiology. CONTENTS: Introduction; Radiation protection; Embolotherapy; Interventional techniques in the management of gastrointestinal bleeding; Transluminal angioplasty; Thrombolytic therapy; Foreign body removal; Inferior vena cava filter placement; Percutaneous uroradiologic techniques; Interventional techniques in the biliary tract; Nonvascular gastrointestinal tract dilations; Percutaneous biopsy techniques; Drainage of abscess fluid collections in the abdomen.

  19. Orthopaedic radiology

    SciTech Connect

    Park, W.M.; Hughes, S.P.F.

    1985-01-01

    This book provides an account of the principles of modern diagnostic imaging techniques and their applications in orthopedics. The aim of the book is to show radiology as a dynamic subject which can help clinicians, while at the same time assisting radiologists to understand the needs of the orthopedic surgeon.

  20. Spurious Behavior of Shock-Capturing Methods: Problems Containing Stiff Source Terms and Discontinuities

    NASA Technical Reports Server (NTRS)

    Yee, Helen M. C.; Kotov, D. V.; Wang, Wei; Shu, Chi-Wang

    2013-01-01

    The goal of this paper is to relate numerical dissipations that are inherited in high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities. For pointwise evaluation of the source term, previous studies indicated that the phenomenon of wrong propagation speed of discontinuities is connected with the smearing of the discontinuity caused by the discretization of the advection term. The smearing introduces a nonequilibrium state into the calculation. Thus as soon as a nonequilibrium value is introduced in this manner, the source term turns on and immediately restores equilibrium, while at the same time shifting the discontinuity to a cell boundary. The present study is to show that the degree of wrong propagation speed of discontinuities is highly dependent on the accuracy of the numerical method. The manner in which the smearing of discontinuities is contained by the numerical method and the overall amount of numerical dissipation being employed play major roles. Moreover, employing finite time steps and grid spacings that are below the standard Courant-Friedrich-Levy (CFL) limit on shockcapturing methods for compressible Euler and Navier-Stokes equations containing stiff reacting source terms and discontinuities reveals surprising counter-intuitive results. Unlike non-reacting flows, for stiff reactions with discontinuities, employing a time step and grid spacing that are below the CFL limit (based on the homogeneous part or non-reacting part of the governing equations) does not guarantee a correct solution of the chosen governing equations. Instead, depending on the numerical method, time step and grid spacing, the numerical simulation may lead to (a) the correct solution (within the truncation error of the scheme), (b) a divergent solution, (c) a wrong propagation speed of discontinuities solution or (d) other spurious solutions that are solutions of the discretized counterparts but are not solutions of the governing equations

  1. SARNET: Integrating Severe Accident Research in Europe - Safety Issues in the Source Term Area

    SciTech Connect

    Haste, T.; Giordano, P.; Micaelli, J.-C.; Herranz, L.

    2006-07-01

    SARNET (Severe Accident Research Network) is a Network of Excellence of the EU 6. Framework Programme that integrates in a sustainable manner the research capabilities of about fifty European organisations to resolve important remaining uncertainties and safety issues concerning existing and future nuclear plant, especially water-cooled reactors, under hypothetical severe accident conditions. It emphasises integrating activities, spreading of excellence (including knowledge transfer) and jointly-executed research. This paper summarises the main results obtained at the middle of the current 4-year term, highlighting those concerning radioactive release to the environment. Integration is pursued through different methods: the ASTEC integral computer code for severe accident modelling, development of PSA level 2 methods, a means for definition, updating and resolution of safety issues, and development of a web database for storing experimental results. These activities are helped by an evolving Advanced Communication Tool, easing communication amongst partners. Concerning spreading of excellence, educational courses covering severe accident analysis methodology and level 2 PSA have been organised for early 2006. A text book on Severe Accident Phenomenology is being written. A mobility programme for students and young researchers has started. Results are disseminated mainly through open conference proceedings, with journal publications planned. The 1. European Review Meeting on Severe Accidents in November 2005 covered SARNET activities during its first 18 months. Jointly executed research activities concern key issues grouped in the Corium, Containment and Source Term areas. In Source Term, behaviour of the highly radio-toxic ruthenium under oxidising conditions, including air ingress, is investigated. Models are proposed for fuel and ruthenium oxidation. Experiments on transport of oxide ruthenium species are performed. Reactor scenario studies assist in defining

  2. Accident source terms for light-water nuclear power plants using high-burnup or MOX fuel.

    SciTech Connect

    Salay, Michael; Gauntt, Randall O.; Lee, Richard Y.; Powers, Dana Auburn; Leonard, Mark Thomas

    2011-01-01

    Representative accident source terms patterned after the NUREG-1465 Source Term have been developed for high burnup fuel in BWRs and PWRs and for MOX fuel in a PWR with an ice-condenser containment. These source terms have been derived using nonparametric order statistics to develop distributions for the timing of radionuclide release during four accident phases and for release fractions of nine chemical classes of radionuclides as calculated with the MELCOR 1.8.5 accident analysis computer code. The accident phases are those defined in the NUREG-1465 Source Term - gap release, in-vessel release, ex-vessel release, and late in-vessel release. Important differences among the accident source terms derived here and the NUREG-1465 Source Term are not attributable to either fuel burnup or use of MOX fuel. Rather, differences among the source terms are due predominantly to improved understanding of the physics of core meltdown accidents. Heat losses from the degrading reactor core prolong the process of in-vessel release of radionuclides. Improved understanding of the chemistries of tellurium and cesium under reactor accidents changes the predicted behavior characteristics of these radioactive elements relative to what was assumed in the derivation of the NUREG-1465 Source Term. An additional radionuclide chemical class has been defined to account for release of cesium as cesium molybdate which enhances molybdenum release relative to other metallic fission products.

  3. Long-term particle measurements in Finnish Arctic: Part II - Trend analysis and source location identification

    NASA Astrophysics Data System (ADS)

    Laing, James R.; Hopke, Philip K.; Hopke, Eleanor F.; Husain, Liaquat; Dutkiewicz, Vincent A.; Paatero, Jussi; Viisanen, Yrjö.

    2014-05-01

    Forty-seven years (1964-2010) of weekly trace metal and major ion concentrations in total suspended particle samples from Kevo, Finland were analyzed for long-term trends and by source identification methods. Significant long-term decreasing trends were detected for most species. The largest decreases over the 47 years were Sb (-3.90% yr-1), Pb (-3.87% yr-1), Mn (-3.45% yr-1), Cd (-3.42% yr-1), and Ca (-3.13% yr-1). As, Pb, and Cd concentrations at Kevo were consistent with the reported time-trends of European emissions inventories. Pb concentrations at Kevo have dramatically decreased (92%) in the past 47 years due to the reduced use of leaded gasoline in automobiles. Back-trajectory analysis suggests that the main source areas of anthropogenic species (V, Cd, Mn, Mo, Sb, Tl, W) were predominantly in Eastern Europe, European Russia, and the Baltics. Markers of stationary fuel combustion (V, Mn, Mo, Sb, Se, and Tl) pointed towards source regions in the Pechora Basin and Ural industrial areas in Russia, and near gas and oil fields in western Kazakhstan.

  4. The Multimedia Environmental Pollutant Assessment System (MEPAS){reg_sign}: Source-term release formulations

    SciTech Connect

    Streile, G.P.; Shields, K.D.; Stroh, J.L.; Bagaasen, L.M.; Whelan, G.; McDonald, J.P.; Droppo, J.G.; Buck, J.W.

    1996-11-01

    This report is one of a series of reports that document the mathematical models in the Multimedia Environmental Pollutant Assessment System (MEPAS). Developed by Pacific Northwest National Laboratory for the US Department of Energy, MEPAS is an integrated impact assessment software implementation of physics-based fate and transport models in air, soil, and water media. Outputs are estimates of exposures and health risk assessments for radioactive and hazardous pollutants. Each of the MEPAS formulation documents covers a major MEPAS component such as source-term, atmospheric, vadose zone/groundwater, surface water, and health exposure/health impact assessment. Other MEPAS documentation reports cover the sensitivity/uncertainty formulations and the database parameter constituent property estimation methods. The pollutant source-term release component is documented in this report. MEPAS simulates the release of contaminants from a source, transport through the air, groundwater, surface water, or overland pathways, and transfer through food chains and exposure pathways to the exposed individual or population. For human health impacts, risks are computed for carcinogens and hazard quotients for noncarcinogens. MEPAS is implemented on a desktop computer with a user-friendly interface that allows the user to define the problem, input the required data, and execute the appropriate models for both deterministic and probabilistic analyses.

  5. Long-term X-ray variability of ultraluminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Lin, Lupin Chun-Che; Hu, Chin-Ping; Kong, Albert K. H.; Yen, David Chien-Chang; Takata, Jumpei; Chou, Yi

    2015-12-01

    Long-term X-ray modulations on time-scales from tens to hundreds of days have been widely studied for X-ray binaries located in the Milky Way and the Magellanic Clouds. For other nearby galaxies, only the most luminous X-ray sources can be monitored with dedicated observations. We here present the first systematic study of long-term X-ray variability of four ultraluminous X-ray sources (ESO 243-49 HLX-1, Holmberg IX X-1, M81 X-6, and NGC 5408 X-1) monitored with Swift. By using various dynamic techniques to analyse their light curves, we find several interesting low-frequency quasi-periodicities. Although the periodic signals may not represent any stable orbital modulations, these detections reveal that such long-term regular patterns may be related to superorbital periods and structure of the accretion discs. In particular, we show that the outburst recurrence time of ESO 243-49 HLX-1 varies over time and suggest that it may not be the orbital period. Instead, it may be due to some kinds of precession, and the true binary period is expected to be much shorter.

  6. Technical considerations related to interim source-term assumptions for emergency planning and equipment qualification. [PWR; BWR

    SciTech Connect

    Niemczyk, S.J.; McDowell-Boyer, L.M.

    1982-09-01

    The source terms recommended in the current regulatory guidance for many considerations of light water reactor (LWR) accidents were developed a number of years ago when understandings of many of the phenomena pertinent to source term estimation were relatively primitive. The purpose of the work presented here was to develop more realistic source term assumptions which could be used for interim regulatory purposes for two specific considerations, namely, equipment qualification and emergency planning. The overall approach taken was to adopt assumptions and models previously proposed for various aspects of source term estimation and to modify those assumptions and models to reflect recently gained insights into, and data describing, the release and transport of radionuclides during and after LWR accidents. To obtain illustrative estimates of the magnitudes of the source terms, the results of previous calculations employing the adopted assumptions and models were utilized and were modified to account for the effects of the recent insights and data.

  7. Operational source term estimation and ensemble prediction for the Grimsvoetn 2011 event

    NASA Astrophysics Data System (ADS)

    Maurer, Christian; Arnold, Delia; Klonner, Robert; Wotawa, Gerhard

    2014-05-01

    The ESA-funded international project VAST (Volcanic Ash Strategic Initiative Team) includes focusing on a realistic source term estimation in the case of volcanic eruptions as well as on an estimate of the forecast uncertainty in the resulting atmospheric dispersion calculations, which partly derive from the forecast uncertainty in the meteorological input data. SEVIRI earth observation data serve as a basis for the source term estimation, from which the total atmospheric column ash content can be estimated. In an operational environment, the already available EUMETCAST VOLE product may be used. Further an a priori source term is needed, which can be coarsely estimated according to information from previous eruptions and/or constrained with observations of the eruption column. The link between observations and the a priori source is established by runs of the atmospheric transport model FLEXPART for individual emission periods and a predefined number of vertical levels. Through minimizing the differences between observations and model results the so-called a posteriori source term can be depicted for a certain time interval as a function of height. Such a result is shown for a first test case, the eruption of the Grimsvoetn volcano on Iceland in May 2011. Once the dispersion calculations are as optimized as possible with regard to the source term, the uncertainty stemming from the forecast uncertainty of the numeric weather prediction model used is still present, adding up to the unavoidable model errors. Since it is impossible to perform FLEXPART runs for all 50 members of the Integrated Forecasting System (IFS) of ECMWF due to computational (time-storage) constraints, the number of members gets restricted to five (maximum seven) representative runs via cluster analysis. The approach used is as of Klonner (2012) where it was demonstrated that exclusive consideration of the wind components on a pressure level (e.g. 400 hPa) makes it possible to find clusters and

  8. A probabilistic assessment of the chemical and radiological risks of chronic exposure to uranium in freshwater ecosystems.

    PubMed

    Mathews, Teresa; Beaugelin-Seiller, Karine; Garnier-Laplace, Jacqueline; Gilbin, Rodolphe; Adam, Christelle; Della-Vedova, Claire

    2009-09-01

    Uranium (U) presents a unique challenge for ecological risk assessments (ERA) because it induces both chemical and radiological toxicity, and the relative importance of these two toxicities differs among the various U source terms (i.e., natural, enriched, depleted). We present a method for the conversion between chemical concentrations microg L(-1)) and radiological dose rates (microGy h(-1)) for a defined set of reference organisms, and apply this conversion method to previously derived chemical and radiological benchmarks to determine the extent to which these benchmarks ensure radiological and chemical protection, respectively, for U in freshwater ecosystems. Results show that the percentage of species radiologically protected by the chemical benchmark decreases with increasing degrees of U enrichment and with increasing periods of radioactive decay. In contrast, the freshwater ecosystem is almost never chemically protected by the radiological benchmark, regardless of the source term or decay period considered, confirming that the risks to the environment from uranium's chemical toxicity generally outweigh those of its radiological toxicity. These results are relevant to developing water quality criteria that protect freshwater ecosystems from the various risks associated with the nuclear applications of U exploitation, and highlight the need for (1) further research on the speciation, bioavailability, and toxicity of U-series radionuclides under different environmental conditions, and (2) the adoption of both chemical and radiological benchmarks for coherent ERAs to be conducted in U-contaminated freshwater ecosystems. PMID:19764235

  9. A Probabilistic Assessment of the Chemical and Radiological Risks of Chronic Exposure to Uranium in Freshwater Ecosystems

    SciTech Connect

    Mathews, Teresa J

    2009-01-01

    Uranium (U) presents a unique challenge for ecological risk assessments (ERA) because it induces both chemical and radiological toxicity, and the relative importance of these two toxicities differs among the various U source terms (i.e., natural, enriched, depleted). We present a method for the conversion between chemical concentrations microg L(-1)) and radiological dose rates (microGy h(-1)) for a defined set of reference organisms, and apply this conversion method to previously derived chemical and radiological benchmarks to determine the extent to which these benchmarks ensure radiological and chemical protection, respectively, for U in freshwater ecosystems. Results show that the percentage of species radiologically protected by the chemical benchmark decreases with increasing degrees of U enrichment and with increasing periods of radioactive decay. In contrast, the freshwater ecosystem is almost never chemically protected by the radiological benchmark, regardless of the source term or decay period considered, confirming that the risks to the environment from uranium's chemical toxicity generally outweigh those of its radiological toxicity. These results are relevant to developing water quality criteria that protect freshwater ecosystems from the various risks associated with the nuclear applications of U exploitation, and highlight the need for (1) further research on the speciation, bioavailability, and toxicity of U-series radionuclides under different environmental conditions, and (2) the adoption of both chemical and radiological benchmarks for coherent ERAs to be conducted in U-contaminated freshwater ecosystems.

  10. A Comprehensive Probabilistic Tsunami Hazard Assessment: Multiple Sources and Short-Term Interactions

    NASA Astrophysics Data System (ADS)

    Anita, G.; Selva, J.; Laura, S.

    2011-12-01

    We develop a comprehensive and total probabilistic tsunami hazard assessment (TotPTHA), in which many different possible source types concur to the definition of the total tsunami hazard at given target sites. In a multi-hazard and multi-risk perspective, such an innovative approach allows, in principle, to consider all possible tsunamigenic sources, from seismic events, to slides, asteroids, volcanic eruptions, etc. In this respect, we also formally introduce and discuss the treatment of interaction/cascade effects in the TotPTHA analysis. We demonstrate how external triggering events may induce significant temporary variations in the tsunami hazard. Because of this, such effects should always be considered, at least in short-term applications, to obtain unbiased analyses. Finally, we prove the feasibility of the TotPTHA and of the treatment of interaction/cascade effects by applying this methodology to an ideal region with realistic characteristics (Neverland).

  11. The long-term oscillations in sunspots and related inter-sunspot sources in microwave emission

    NASA Astrophysics Data System (ADS)

    Bakunina, I. A.; Abramov-Maximov, V. E.; Smirnova, V. V.

    2016-02-01

    This work presents the microwave long-term oscillations with periods of a few tens of minutes obtained from Nobeyama radioheliograph (NoRH) at frequency 17 GHz. In two active regions the fluctuations of radio emission of different types of intersunspot sources (ISS) (compact and extended) were compared with the fluctuations in magnetic fields of sunspots. Common periods in variations of microwave emission of different type of sources and magnetic field of sunspots were discovered. The delay of 17 minutes was revealed for oscillations of the extended ISS with respect to variations of magnetic field of its tail sunspot. The model of the sunspot magnetic structure based on the concept of three magnetic fluxes for explanation of this fact is discussed.

  12. PHENOstruct: Prediction of human phenotype ontology terms using heterogeneous data sources

    PubMed Central

    Kahanda, Indika; Funk, Christopher; Verspoor, Karin; Ben-Hur, Asa

    2015-01-01

    The human phenotype ontology (HPO) was recently developed as a standardized vocabulary for describing the phenotype abnormalities associated with human diseases. At present, only a small fraction of human protein coding genes have HPO annotations. But, researchers believe that a large portion of currently unannotated genes are related to disease phenotypes. Therefore, it is important to predict gene-HPO term associations using accurate computational methods. In this work we demonstrate the performance advantage of the structured SVM approach which was shown to be highly effective for Gene Ontology term prediction in comparison to several baseline methods. Furthermore, we highlight a collection of informative data sources suitable for the problem of predicting gene-HPO associations, including large scale literature mining data. PMID:26834980

  13. Numerical Dissipation and Wrong Propagation Speed of Discontinuities for Stiff Source Terms

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Kotov, D. V.; Sjoegreen, B.

    2012-01-01

    In compressible turbulent combustion/nonequilibrium flows, the constructions of numerical schemes for (a) stable and accurate simulation of turbulence with strong shocks, and (b) obtaining correct propagation speed of discontinuities for stiff reacting terms on coarse grids share one important ingredient - minimization of numerical dissipation while maintaining numerical stability. Here coarse grids means standard mesh density requirement for accurate simulation of typical non-reacting flows. This dual requirement to achieve both numerical stability and accuracy with zero or minimal use of numerical dissipation is most often conflicting for existing schemes that were designed for non-reacting flows. The goal of this paper is to relate numerical dissipations that are inherited in a selected set of high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities as a function of stiffness of the source term and the grid spacing.

  14. Long-term storage life of light source modules by temperature cycling accelerated life test

    NASA Astrophysics Data System (ADS)

    Ningning, Sun; Manqing, Tan; Ping, Li; Jian, Jiao; Xiaofeng, Guo; Wentao, Guo

    2014-05-01

    Light source modules are the most crucial and fragile devices that affect the life and reliability of the interferometric fiber optic gyroscope (IFOG). While the light emitting chips were stable in most cases, the module packaging proved to be less satisfactory. In long-term storage or the working environment, the ambient temperature changes constantly and thus the packaging and coupling performance of light source modules are more likely to degrade slowly due to different materials with different coefficients of thermal expansion in the bonding interface. A constant temperature accelerated life test cannot evaluate the impact of temperature variation on the performance of a module package, so the temperature cycling accelerated life test was studied. The main failure mechanism affecting light source modules is package failure due to solder fatigue failure including a fiber coupling shift, loss of cooling efficiency and thermal resistor degradation, so the Norris-Landzberg model was used to model solder fatigue life and determine the activation energy related to solder fatigue failure mechanism. By analyzing the test data, activation energy was determined and then the mean life of light source modules in different storage environments with a continuously changing temperature was simulated, which has provided direct reference data for the storage life prediction of IFOG.

  15. Short-term spatial change in a volcanic tremor source during the 2011 Kirishima eruption

    NASA Astrophysics Data System (ADS)

    Matsumoto, Satoshi; Shimizu, Hiroshi; Matsushima, Takeshi; Uehira, Kenji; Yamashita, Yusuke; Nakamoto, Manami; Miyazaki, Masahiro; Chikura, Hiromi

    2013-04-01

    Volcanic tremors are indicators of magmatic behavior, which is strongly related to volcanic eruptions and activity. Detection of spatial and temporal variations in the source location is important for understanding the mechanism of volcanic eruptions. However, short-term temporal variations within a tremor event have not always been detected by seismic array observations around volcanoes. Here, we show that volcanic tremor sources were activated at both the top (i.e., the crater) and the lower end of the conduit, by analyzing seismograms from a dense seismic array 3 km from the Shinmoedake crater, Kirishima volcano, Japan. We observed changes in the seismic ray direction during a volcanic tremor sequence, and inferred two major sources of the tremor from the slowness vectors of the approaching waves. One was located in a shallow region beneath the Shinmoedake crater. The other was found in a direction N30°W from the array, pointing to a location above a pressure source. The fine spatial and temporal characteristics of volcanic tremors suggest an interaction between deep and shallow conduits.

  16. EXPERIENCES FROM THE SOURCE-TERM ANALYSIS OF A LOW AND INTERMEDIATE LEVEL RADWASTE DISPOSAL FACILITY

    SciTech Connect

    Park,Jin Beak; Park, Joo-Wan; Lee, Eun-Young; Kim, Chang-Lak

    2003-02-27

    Enhancement of a computer code SAGE for evaluation of the Korean concept for a LILW waste disposal facility is discussed. Several features of source term analysis are embedded into SAGE to analyze: (1) effects of degradation mode of an engineered barrier, (2) effects of dispersion phenomena in the unsaturated zone and (3) effects of time dependent sorption coefficient in the unsaturated zone. IAEA's Vault Safety Case (VSC) approach is used to demonstrate the ability of this assessment code. Results of MASCOT are used for comparison purposes. These enhancements of the safety assessment code, SAGE, can contribute to realistic evaluation of the Korean concept of the LILW disposal project in the near future.

  17. The source term and waste optimization of molten salt reactors with processing

    SciTech Connect

    Gat, U.; Dodds, H.L.

    1993-07-01

    The source term of a molten salt reactor (MSR) with fuel processing is reduced by the ratio of processing time to refueling time as compared to solid fuel reactors. The reduction, which can be one to two orders of magnitude, is due to removal of the long-lived fission products. The waste from MSRs can be optimized with respect to its chemical composition, concentration, mixture, shape, and size. The actinides and long-lived isotopes can be separated out and returned to the reactor for transmutation. These features make MSRs more acceptable and simpler in operation and handling.

  18. SOURCE TERM REMEDIATION & DEMOLITION STRATEGY FOR THE HANFORD K-AREA SPENT FUEL BASINS

    SciTech Connect

    CHRONISTER, G.B.

    2006-03-23

    This paper discusses the technologies applied at Hanford's K-Basins to mitigate risk and reduce the source term in preparing the basins for deactivation and demolition. These project technologies/strategies (in various stages of implementation) are sequential in nature and are the basis for preparing to dispose of the K Basins--two highly contaminated concrete basins at the Hanford Site in southeastern Washington State. A large collection of spent nuclear fuel stored for many years underwater at the K Basins has been removed to stable, dry, safe storage. Remediation activities are underway to prepare the basin structures for de-inventory, decontamination, and disposal.

  19. An Exact Form of Lilley's Equation with a Velocity Quadrupole/Temperature Dipole Source Term

    NASA Technical Reports Server (NTRS)

    Goldstein, Marvin E.

    2001-01-01

    There have been several attempts to introduce approximations into the exact form of Lilley's equation in order to express the source term as the sum of a quadrupole whose strength is quadratic in the fluctuating velocities and a dipole whose strength is proportional to the temperature fluctuations. The purpose of this note is to show that it is possible to choose the dependent (i.e., the pressure) variable so that this type of result can be derived directly from the Euler equations without introducing any additional approximations.

  20. On the numerical treatment of nonlinear source terms in reaction-convection equations

    NASA Technical Reports Server (NTRS)

    Lafon, A.; Yee, H. C.

    1992-01-01

    The objectives of this paper are to investigate how various numerical treatments of the nonlinear source term in a model reaction-convection equation can affect the stability of steady-state numerical solutions and to show under what conditions the conventional linearized analysis breaks down. The underlying goal is to provide part of the basic building blocks toward the ultimate goal of constructing suitable numerical schemes for hypersonic reacting flows, combustions and certain turbulence models in compressible Navier-Stokes computations. It can be shown that nonlinear analysis uncovers much of the nonlinear phenomena which linearized analysis is not capable of predicting in a model reaction-convection equation.

  1. PORTER: a Prototype System for Patient-Oriented Radiology Reporting.

    PubMed

    Oh, Seong Cheol; Cook, Tessa S; Kahn, Charles E

    2016-08-01

    To empower patients to participate in their medical care and decision-making, effective communication is critical. In radiology, the clinical report is the primary medium of communication. Although radiologists historically have authored reports with the referring provider as the intended reader, patients increasingly access the reports through portals to electronic health record systems. We developed a system named PORTER (Patient-Oriented Radiology Reporter) to augment radiology reports with lay-language definitions. Our IRB-approved, HIPAA-compliant study protocol analyzed 100 knee MRI reports from an academic medical center to identify the most commonly utilized terms. A glossary of 313 terms was constructed to include definitions of the terms and, where available, links to reference sources and public-domain images. Flesch-Kincaid readability scores were computed to assure that definitions were readable at or below 10th-grade reading level. The system provided an interactive web site to view outpatient knee MRI exams. After logging in with their exam ID number and date of birth, patients viewed their report annotated with definitions from the glossary. Applicable images were displayed when the user's mouse hovered over a glossary term. This patient-oriented system can help empower patients to better understand their radiology results. PMID:26856348

  2. Regulatory Technology Development Plan Sodium Fast Reactor. Mechanistic Source Term Development

    SciTech Connect

    Grabaskas, David S.; Brunett, Acacia Joann; Bucknor, Matthew D.; Sienicki, James J.; Sofu, Tanju

    2015-02-28

    Construction and operation of a nuclear power installation in the U.S. requires licensing by the U.S. Nuclear Regulatory Commission (NRC). A vital part of this licensing process and integrated safety assessment entails the analysis of a source term (or source terms) that represents the release of radionuclides during normal operation and accident sequences. Historically, nuclear plant source term analyses have utilized deterministic, bounding assessments of the radionuclides released to the environment. Significant advancements in technical capabilities and the knowledge state have enabled the development of more realistic analyses such that a mechanistic source term (MST) assessment is now expected to be a requirement of advanced reactor licensing. This report focuses on the state of development of an MST for a sodium fast reactor (SFR), with the intent of aiding in the process of MST definition by qualitatively identifying and characterizing the major sources and transport processes of radionuclides. Due to common design characteristics among current U.S. SFR vendor designs, a metal-fuel, pool-type SFR has been selected as the reference design for this work, with all phenomenological discussions geared toward this specific reactor configuration. This works also aims to identify the key gaps and uncertainties in the current knowledge state that must be addressed for SFR MST development. It is anticipated that this knowledge state assessment can enable the coordination of technology and analysis tool development discussions such that any knowledge gaps may be addressed. Sources of radionuclides considered in this report include releases originating both in-vessel and ex-vessel, including in-core fuel, primary sodium and cover gas cleanup systems, and spent fuel movement and handling. Transport phenomena affecting various release groups are identified and qualitatively discussed, including fuel pin and primary coolant retention, and behavior in the cover gas and

  3. User`s Manual for the SOURCE1 and SOURCE2 Computer Codes: Models for Evaluating Low-Level Radioactive Waste Disposal Facility Source Terms (Version 2.0)

    SciTech Connect

    Icenhour, A.S.; Tharp, M.L.

    1996-08-01

    The SOURCE1 and SOURCE2 computer codes calculate source terms (i.e. radionuclide release rates) for performance assessments of low-level radioactive waste (LLW) disposal facilities. SOURCE1 is used to simulate radionuclide releases from tumulus-type facilities. SOURCE2 is used to simulate releases from silo-, well-, well-in-silo-, and trench-type disposal facilities. The SOURCE codes (a) simulate the degradation of engineered barriers and (b) provide an estimate of the source term for LLW disposal facilities. This manual summarizes the major changes that have been effected since the codes were originally developed.

  4. Chest radiology

    SciTech Connect

    Reed, J.C.

    1990-01-01

    This book is a reference in plain chest film diagnosis provides a thorough background in the differential diagnosis of 22 of the most common radiologic patterns of chest disease. Each chapter is introduced with problem cases and a set of questions, followed by a tabular listing of the appropriate differential considerations. The book emphasizes plain films, CT and some MR scans are integrated to demonstrate how these modalities enhance the work of a case.

  5. Genitourinary radiology

    SciTech Connect

    McClennan, B.L.

    1982-01-01

    A literature review of genitourinary radiology highlights new findings in the field that have occurred in the past year. The physiology of contrast media, and the occasional life-threatening contrast medial reaction are discussed. Common urologic problems such as stones, infection, and obstruction are examined in order to interpret static radiographs in a more meaningful way. The field of interventional uroradiology continues to expand, with new procedures being tried and new indications for old procedures being developed. (KRM)

  6. Assessment of SRS radiological liquid and airborne contaminants and pathways

    SciTech Connect

    Jannik, G.T.

    1997-04-01

    This report compiles and documents the radiological critical-contaminant/critical-pathway analysis performed for SRS. The analysis covers radiological releases to the atmosphere and to surface water, which are the principal media that carry contaminants off site. During routine operations at SRS, limited amounts of radionuclides are released to the environment through atmospheric and/or liquid pathways. These releases potentially result in exposure to offsite people. Though the groundwater beneath an estimated 5 to 10 percent of SRS has been contaminated by radionuclides, there is no evidence that groundwater contaminated with these constituents has migrated offsite (Arnett, 1996). Therefore, with the notable exception of radiological source terms originating from shallow surface water migration into site streams, onsite groundwater was not considered as a potential exposure pathway to offsite people.

  7. FDH radiological design review guidelines

    SciTech Connect

    Millsap, W.J.

    1998-09-29

    These guidelines discuss in more detail the radiological design review process used by the Project Hanford Management Contractors as described in HNF-PRO-1622, Radiological Design Review Process. They are intended to supplement the procedure by providing background information on the design review process and providing a ready source of information to design reviewers. The guidelines are not intended to contain all the information in the procedure, but at points, in order to maintain continuity, they contain some of the same information.

  8. The Analytical Repository Source-Term (AREST) model: Description and documentation

    SciTech Connect

    Liebetrau, A.M.; Apted, M.J.; Engel, D.W.; Altenhofen, M.K.; Strachan, D.M.; Reid, C.R.; Windisch, C.F.; Erikson, R.L.; Johnson, K.I.

    1987-10-01

    The geologic repository system consists of several components, one of which is the engineered barrier system. The engineered barrier system interfaces with natural barriers that constitute the setting of the repository. A model that simulates the releases from the engineered barrier system into the natural barriers of the geosphere, called a source-term model, is an important component of any model for assessing the overall performance of the geologic repository system. The Analytical Repository Source-Term (AREST) model being developed is one such model. This report describes the current state of development of the AREST model and the code in which the model is implemented. The AREST model consists of three component models and five process models that describe the post-emplacement environment of a waste package. All of these components are combined within a probabilistic framework. The component models are a waste package containment (WPC) model that simulates the corrosion and degradation processes which eventually result in waste package containment failure; a waste package release (WPR) model that calculates the rates of radionuclide release from the failed waste package; and an engineered system release (ESR) model that controls the flow of information among all AREST components and process models and combines release output from the WPR model with failure times from the WPC model to produce estimates of total release. 167 refs., 40 figs., 12 tabs.

  9. Projected Source Terms for Potential Sabotage Events Related to Spent Fuel Shipments

    SciTech Connect

    Luna, R.E.; Neuhauser, K.S.; Vigil, M.G.

    1999-06-01

    Two major studies, one sponsored by the U.S. Department of Energy and the other by the U.S. Nuclear Regulatory Commission, were conducted in the late 1970s and early 1980s to provide information and source terms for an optimally successful act of sabotage on spent fuel casks typical of those available for use. This report applies the results of those studies and additional analysis to derive potential source terms for certain classes of sabotage events on spent fuel casks and spent fuel typical of those which could be shipped in the early decades of the 21st century. In addition to updating the cask and spent fuel characteristics used in the analysis, two release mechanisms not included in the earlier works were identified and evaluated. As would be expected, inclusion of these additional release mechanisms resulted in a somewhat higher total release from the postulated sabotage events. Although health effects from estimated releases were addressed in the earlier study conducted for U.S. Department of Energy, they have not been addressed in this report. The results from this report maybe used to estimate health effects.

  10. Source-term development for a contaminant plume for use by multimedia risk assessment models

    SciTech Connect

    Whelan, Gene ); McDonald, John P. ); Taira, Randal Y. ); Gnanapragasam, Emmanuel K.; Yu, Charley; Lew, Christine S.; Mills, William B.

    1999-12-01

    Multimedia modelers from the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE) are collaborating to conduct a comprehensive and quantitative benchmarking analysis of four intermedia models: DOE's Multimedia Environmental Pollutant Assessment System (MEPAS), EPA's MMSOILS, EPA's PRESTO, and DOE's RESidual RADioactivity (RESRAD). These models represent typical analytically, semi-analytically, and empirically based tools that are utilized in human risk and endangerment assessments for use at installations containing radioactive and/or hazardous contaminants. Although the benchmarking exercise traditionally emphasizes the application and comparison of these models, the establishment of a Conceptual Site Model (CSM) should be viewed with equal importance. This paper reviews an approach for developing a CSM of an existing, real-world, Sr-90 plume at DOE's Hanford installation in Richland, Washington, for use in a multimedia-based benchmarking exercise bet ween MEPAS, MMSOILS, PRESTO, and RESRAD. In an unconventional move for analytically based modeling, the benchmarking exercise will begin with the plume as the source of contamination. The source and release mechanism are developed and described within the context of performing a preliminary risk assessment utilizing these analytical models. By beginning with the plume as the source term, this paper reviews a typical process and procedure an analyst would follow in developing a CSM for use in a preliminary assessment using this class of analytical tool.

  11. Environmental radiation safety: source term modification by soil aerosols. Interim report

    SciTech Connect

    Moss, O.R.; Allen, M.D.; Rossignol, E.J.; Cannon, W.C.

    1980-08-01

    The goal of this project is to provide information useful in estimating hazards related to the use of a pure refractory oxide of /sup 238/Pu as a power source in some of the space vehicles to be launched during the next few years. Although the sources are designed and built to withstand re-entry into the earth's atmosphere, and to impact with the earth's surface without releasing any plutonium, the possibility that such an event might produce aerosols composed of soil and /sup 238/PuO/sub 2/ cannot be absolutely excluded. This report presents the results of our most recent efforts to measure the degree to which the plutonium aerosol source term might be modified in a terrestrial environment. The five experiments described represent our best effort to use the original experimental design to study the change in the size distribution and concentration of a /sup 238/PuO/sub 2/ aerosol due to coagulation with an aerosol of clay or sandy loam soil.

  12. Plutonium isotopes and 241Am in the atmosphere of Lithuania: A comparison of different source terms

    NASA Astrophysics Data System (ADS)

    Lujanienė, G.; Valiulis, D.; Byčenkienė, S.; Šakalys, J.; Povinec, P. P.

    2012-12-01

    137Cs, 241Am and Pu isotopes collected in aerosol samples during 1994-2011 were analyzed with special emphasis on better understanding of Pu and Am behavior in the atmosphere. The results from long-term measurements of 240Pu/239Pu atom ratios showed a bimodal frequency distribution with median values of 0.195 and 0.253, indicating two main sources contributing to the Pu activities at the Vilnius sampling station. The low Pu atom ratio of 0.141 could be attributed to the weapon-grade plutonium derived from the nuclear weapon test sites. The frequency of air masses arriving from the North-West and North-East correlated with the Pu atom ratio indicating the input from the sources located in these regions (the Novaya Zemlya test site, Siberian nuclear plants), while no correlation with the Chernobyl region was observed. Measurements carried out during the Fukushima accident showed a negligible impact of this source with Pu activities by four orders of magnitude lower as compared to the Chernobyl accident. The activity concentration of actinides measured in the integrated sample collected in March-April, 2011 showed a small contribution of Pu with unusual activity and atom ratios indicating the presence of the spent fuel of different origin than that of the Chernobyl accident.

  13. DUSTMS-D: DISPOSAL UNIT SOURCE TERM - MULTIPLE SPECIES - DISTRIBUTED FAILURE DATA INPUT GUIDE.

    SciTech Connect

    SULLIVAN, T.M.

    2006-01-01

    Performance assessment of a low-level waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). Many of these physical processes are influenced by the design of the disposal facility (e.g., how the engineered barriers control infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This has been done and the resulting models have been incorporated into the computer code DUST-MS (Disposal Unit Source Term-Multiple Species). The DUST-MS computer code is designed to model water flow, container degradation, release of contaminants from the wasteform to the contacting solution and transport through the subsurface media. Water flow through the facility over time is modeled using tabular input. Container degradation models include three types of failure rates: (a) instantaneous (all containers in a control volume fail at once), (b) uniformly distributed failures (containers fail at a linear rate between a specified starting and ending time), and (c) gaussian failure rates (containers fail at a rate determined by a mean failure time, standard deviation and gaussian distribution). Wasteform release models include four release mechanisms: (a) rinse with partitioning (inventory is released instantly upon container failure subject to equilibrium partitioning (sorption) with

  14. Detecting Long-term Changes in Point Source Fossil CO2 Emissions with Tree Ring Archives

    NASA Astrophysics Data System (ADS)

    Keller, E. D.; Turnbull, J. C.; Norris, M. W.

    2015-12-01

    We examine the utility of tree ring 14C archives for detecting long term changes in fossil CO2 emissions from a point source. Trees assimilate carbon from the atmosphere during photosynthesis, in the process faithfully recording the average atmospheric 14C content over the growing season in each annual tree ring. Using 14C as a proxy for fossil CO2, we examine interannual variability over six years of fossil CO2 observations between 2004 and 2012 from two trees growing near the Kapuni Natural Gas Plant in rural Taranaki, New Zealand. We quantify the amount of variability that can be attributed to transport and meteorology by simulating constant point source fossil CO2 emissions over the observation period with the atmospheric transport model WindTrax. We then calculate the amount of change in emissions that we can detect with new observations over annual or multi-year time periods given both measurement uncertainty of 1ppm and the modelled variation in transport. In particular, we ask, what is the minimum amount of change in emissions that we can detect using this method, given a reference period of six years? We find that changes of 42% or more could be detected in a new sample from one year at the pine tree, or 22% in the case of four years of new samples. This threshold lowers and the method becomes more practical with a larger signal; for point sources 10 times the magnitude of the Kapuni plant (a typical size for large electricity generation point sources worldwide), it would be possible to detect sustained emissions changes on the order of 10% given suitable meteorology and observations.

  15. Long Term Leaching of Chlorinated Solvents from Source Zones in Low Permeability Settings with Fractures

    NASA Astrophysics Data System (ADS)

    Bjerg, P. L.; Chambon, J.; Troldborg, M.; Binning, P. J.; Broholm, M. M.; Lemming, G.; Damgaard, I.

    2008-12-01

    Groundwater contamination by chlorinated solvents, such as perchloroethylene (PCE), often occurs via leaching from complex sources located in low permeability sediments such as clayey tills overlying aquifers. Clayey tills are mostly fractured, and contamination migrating through the fractures spreads to the low permeability matrix by diffusion. This results in a long term source of contamination due to back-diffusion. Leaching from such sources is further complicated by microbial degradation under anaerobic conditions to sequentially form the daughter products trichloroethylene, cis-dichloroethylene (cis-DCE), vinyl chloride (VC) and ethene. This process can be enhanced by addition of electron donors and/or bioaugmentation and is termed Enhanced Reductive Dechlorination (ERD). This work aims to improve our understanding of the physical, chemical and microbial processes governing source behaviour under natural and enhanced conditions. That understanding is applied to risk assessment, and to determine the relationship and time frames of source clean up and plume response. To meet that aim, field and laboratory observations are coupled to state of the art models incorporating new insights of contaminant behaviour. The long term leaching of chlorinated ethenes from clay aquitards is currently being monitored at a number of Danish sites. The observed data is simulated using a coupled fracture flow and clay matrix diffusion model. Sequential degradation is represented by modified Monod kinetics accounting for competitive inhibition between the chlorinated ethenes. The model is constructed using Comsol Multiphysics, a generic finite- element partial differential equation solver. The model is applied at two well characterised field sites with respect to hydrogeology, fracture network, contaminant distribution and microbial processes (lab and field experiments). At the study sites (Sortebrovej and Vadsbyvej), the source areas are situated in a clayey till with fractures

  16. Risk management in radiology departments

    PubMed Central

    Craciun, Horea; Mankad, Kshitij; Lynch, Jeremy

    2015-01-01

    Medical imaging and interventional radiology sustained prompt changes in the last few years, mainly as a result of technology breakthroughs, rise in workload, deficit in workforce and globalization. Risk is considered to be the chance or possibility of incurring loss or of a negative event happening that may cause injury to patients or medical practitioners. There are various causes of risks leading to harm and injury in radiology departments, and it is one of the objectives of this paper to scrutinize some of the causes. This will drive to consideration of some of the approaches that are used in managing risks in radiology. This paper aims at investigating risk management in radiology, and this will be achieved through a thorough assessment of the risk control measures that are used in the radiology department. It has been observed that the major focus of risk management in such medical setting is to reduce and eliminate harm and injury to patients through integration of various medical precautions. The field of Radiology is rapidly evolving due to technology advances and the globalization of healthcare. This ongoing development will have a great impact on the level of quality of care and service delivery. Thus, risk management in radiology is essential in protecting the patients, radiologists, and the medical organization in terms of capital and widening of the reputation of the medical organization with the patients. PMID:26120383

  17. Diagnostic radiology 1987

    SciTech Connect

    Margulis, A.R.; Gooding, C.A.

    1987-01-01

    This is the latest version of the continuing education course on diagnostic radiology given yearly by the Department of Radiology at the University of California, San Francisco. The lectures are grouped into sections on gastrointestinal radiology, mammography, uroradiology, magnetic resonance, hepatobiliary radiology, pediatric radiology, ultrasound, interventional radiology, chest radiology, nuclear medicine, cardiovascular radiology, and skeletal radiology. Each section contains four to eight topics. Each of these consists of text that represents highlights in narrative form, selected illustrations, and a short bibliography. The presentation gives a general idea of what points were made in the lecture.

  18. Pediatric radiology

    SciTech Connect

    Silverman, F.N.

    1982-01-01

    A literature review with 186 references of diagnostic pediatric radiology, a speciality restricted to an age group rather than to an organ system or technique of examination, is presented. In the present chapter topics follow the basic organ system divisions with discussions of special techniques within these divisions. The diagnosis of congenital malformations, infectious diseases and neoplasms are a few of the topics discussed for the head and neck region, the vertebrae, the cardiovascular system, the respiratory system, the gastrointestinal tract, the urinary tract, and the skeleton. (KRM)

  19. Methodology and tools for source term assessment in case of emergency.

    PubMed

    Herviou, Karine; Calmtorp, Christer

    2004-01-01

    By looking at the power plant state of fission product barriers and critical safety systems, the magnitude of a potential radioactive release could be predicted in a timely manner to allow emergency response to be executed even before the occurrence of a release. This is the perspective in which the development of ASTRID methodology and tool is performed. The methodology maps out, for several reactor types as well as reactor containments, relevant process parameters and indicators, what and how to calculate and a structured way to summarise and conclude on potential source term and likely time projections. A computer tool is proposed to support the methodology, to suite different user situations, both on-site and off-site as well as size of staff, priority and work order. The output from such an assessment is intended to, first, give bases for decisions on necessary urgent protective actions pre-release, and, second, an input for the sophisticated dispersion calculation codes. PMID:15238656

  20. The Annular Core Research Reactor (ACRR) postulated limiting event initial and building source terms

    SciTech Connect

    Restrepo, L F

    1992-08-01

    As part of the update of the Safety analysis Report (SAR) for the Annular Core Research Reactor (ACRR), operational limiting events under the category of inadvertent withdrawal of an experiment while at power or during a power pulse were determined to be the most limiting event(s) for this reactor. This report provides a summary of the assumptions, modeling, and results in evaluation of: Reactivity and thermal hydraulics analysis to determine the amount of fuel melt or fuel damage ratios; The reactor inventories following the limiting event; A literature review of post NUREG-0772 release fraction experiment results on severe fuel damages; Decontamination factors due to in-pool transport; and In-building transport modeling and building source term analysis.

  1. Long-term Periodicity Analysis of Polarization Variation for Radio Sources

    NASA Astrophysics Data System (ADS)

    Yuan, Yuhai

    2011-06-01

    We use the database of University of Michigan Radio Astronomy Observatory (UMRAO) at three radio bands (4.8, 8 and 14.5 GHz) to analyse the long-term polarization variation in search of the possible periodicity. Using the power spectral analysis method (PSA), the Jurkevich method and the discrete correlation function (DCF) method, we find that there are 16 sources lying in periodicity. The results show the astrophysically meaningful periodicity covering 2.1 years to 16.2 years at 4.8 GHz, 2.8 years to 16.3 years at 8 GHz, and 1.8 years to 16.6 years at 14.5 GHz.

  2. Microbial characterization for the Source-Term Waste Test Program (STTP) at Los Alamos

    SciTech Connect

    Leonard, P.A.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Villarreal, R.

    1999-04-01

    The effects of microbial activity on the performance of the proposed underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico are being studied at Los Alamos National Laboratory (LANL) as part of an ex situ large-scale experiment. Actual actinide-containing waste is being used to predict the effect of potential brine inundation in the repository in the distant future. The study conditions are meant to simulate what might exist should the underground repository be flooded hundreds of years after closure as a result of inadvertent drilling into brine pockets below the repository. The Department of Energy (DOE) selected LANL to conduct the Actinide Source-Term Waste Test Program (STTP) to confirm the predictive capability of computer models being developed at Sandia National Laboratory.

  3. Update to the NARAC NNPP Non-Reactor Source Term Products

    SciTech Connect

    Vogt, P

    2009-06-29

    Recent updates to NARAC plots for NNPP requires a modification to your iClient database. The steps you need to take are described below. Implementation of the non-reactor source terms in February 2009 included four plots, the traditional three instantaneous plots (1-3) and a new Gamma Dose Rate: 1. Particulate Air Concentration 2. Total Ground Deposition 3. Whole Body Inhalation Dose Rate (CEDE Rate) 4. Gamma Dose Rate These plots were all initially implemented to be instantaneous output and generated 30 minutes after the release time. Recently, Bettis and NAVSEA have requested the Whole Body CEDE rate plot to be changed to an integrated dose valid at two hours. This is consistent with the change made to the Thyroid Dose rate plot conversion to a 2-hour Integrated Thyroid dose for the Reactor and Criticality accidents.

  4. Dental radiology.

    PubMed

    Woodward, Tony M

    2009-02-01

    Dental radiology is the core diagnostic modality of veterinary dentistry. Dental radiographs assist in detecting hidden painful pathology, estimating the severity of dental conditions, assessing treatment options, providing intraoperative guidance, and also serve to monitor success of prior treatments. Unfortunately, most professional veterinary training programs provide little or no training in veterinary dentistry in general or dental radiology in particular. Although a technical learning curve does exist, the techniques required for producing diagnostic films are not difficult to master. Regular use of dental x-rays will increase the amount of pathology detected, leading to healthier patients and happier clients who notice a difference in how their pet feels. This article covers equipment and materials needed to produce diagnostic intraoral dental films. A simplified guide for positioning will be presented, including a positioning "cheat sheet" to be placed next to the dental x-ray machine in the operatory. Additionally, digital dental radiograph systems will be described and trends for their future discussed. PMID:19410234

  5. Short-Term Memory Stages in Sign vs. Speech: The Source of the Serial Span Discrepancy

    PubMed Central

    Hall, Matthew L.

    2011-01-01

    Speakers generally outperform signers when asked to recall a list of unrelated verbal items. This phenomenon is well established, but its source has remained unclear. In this study, we evaluate the relative contribution of the three main processing stages of short-term memory – perception, encoding, and recall – in this effect. The present study factorially manipulates whether American Sign Language (ASL) or English was used for perception, memory encoding, and recall in hearing ASL-English bilinguals. Results indicate that using ASL during both perception and encoding contributes to the serial span discrepancy. Interestingly, performing recall in ASL slightly increased span, ruling out the view that signing is in general a poor choice for short-term memory. These results suggest that despite the general equivalence of sign and speech in other memory domains, speech-based representations are better suited for the specific task of perception and memory encoding of a series of unrelated verbal items in serial order through the phonological loop. This work suggests that interpretation of performance on serial recall tasks in English may not translate straightforwardly to serial tasks in sign language. PMID:21450284

  6. Independent assessment of MELCOR as a severe accident thermal-hydraulic/source term analysis tool

    SciTech Connect

    Madni, I.K.; Eltawila, F.

    1994-01-01

    MELCOR is a fully integrated computer code that models all phases of the progression of severe accidents in light water reactor nuclear power plants, and is being developed for the US Nuclear Regulatory Commission (NRC) by Sandia National Laboratories (SNL). Brookhaven National Laboratory (BNL) has a program with the NRC called ``MELCOR Verification, Benchmarking, and Applications,`` whose aim is to provide independent assessment of MELCOR as a severe accident thermal-hydraulic/source term analysis tool. The scope of this program is to perform quality control verification on all released versions of MELCOR, to benchmark MELCOR against more mechanistic codes and experimental data from severe fuel damage tests, and to evaluate the ability of MELCOR to simulate long-term severe accident transients in commercial LWRs, by applying the code to model both BWRs and PWRs. Under this program, BNL provided input to the NRC-sponsored MELCOR Peer Review, and is currently contributing to the MELCOR Cooperative Assessment Program (MCAP). This paper presents a summary of MELCOR assessment efforts at BNL and their contribution to NRC goals with respect to MELCOR.

  7. Neuroimaging Evidence for Agenda-Dependent Monitoring of Different Features during Short-Term Source Memory Tests

    ERIC Educational Resources Information Center

    Mitchell, Karen J.; Raye, Carol L.; McGuire, Joseph T.; Frankel, Hillary; Greene, Erich J.; Johnson, Marcia K.

    2008-01-01

    A short-term source monitoring procedure with functional magnetic resonance imaging assessed neural activity when participants made judgments about the format of 1 of 4 studied items (picture, word), the encoding task performed (cost, place), or whether an item was old or new. The results support findings from long-term memory studies showing that…

  8. Long-term Satellite Observations of Asian Dust Storm: Source, Pathway, and Interannual Variability

    NASA Technical Reports Server (NTRS)

    Hsu, N. Christina

    2008-01-01

    between Deep Blue retrievals of aerosol optical thickness and those directly from AERONET sunphotometers over desert and semi-desert regions. New Deep Blue products will allow scientists to determine quantitatively the aerosol properties near sources using high spatial resolution measurements from SeaWiFS and MODIS-like instruments. Long-term satellite measurements (1998 - 2007) from SeaWiFS will be utilized to investigate the interannual variability of source, pathway, and dust loading associated with the Asian dust storm outbreaks. In addition, monthly averaged aerosol optical thickness during the springtime from SeaWiFS will also be compared with the MODIS Deep Blue products.

  9. Short-term X-ray variability of the globular cluster source 4U 1820 - 30 (NGC 6624)

    NASA Technical Reports Server (NTRS)

    Stella, L.; Kahn, S. M.; Grindlay, J. E.

    1984-01-01

    Analytical techniques for improved identification of the temporal and spectral variability properties of globular cluster and galactic bulge X-ray sources are described in terms of their application to a large set of observations of the source 4U 1820 - 30 in the globular cluster NGC 6624. The autocorrelation function, cross-correlations, time skewness function, erratic periodicities, and pulse trains are examined. The results are discussed in terms of current models with particular emphasis on recent accretion disk models. It is concluded that the analyzed observations provide the first evidence for shot-noise variability in a globular cluster X-ray source.

  10. Radiological-dose assessments of atolls in the northern Marshall Islands

    SciTech Connect

    Robison, W.L.

    1983-04-01

    The Marshall Islands in the Equatorial Pacific, specifically Enewetak and Bikini Atolls, were the site of US nuclear testing from 1946 through 1958. In 1978, the Northern Marshall Islands Radiological Survey was conducted to evaluate the radiological conditions of two islands and ten atolls downwind of the proving grounds. The survey included aerial external gamma measurements and collection of soil, terrestrial, and marine samples for radionuclide analysis to determine the radiological dose from all exposure pathways. The methods and models used to estimate doses to a population in an environment where natural processes have acted on the source-term radionuclides for nearly 30 y, data bases developed for the models, and results of the radiological dose analyses are described.

  11. Source terms released into the environment for a station blackout severe accident at the Peach Bottom Atomic Power Station

    SciTech Connect

    Carbajo, J.J.

    1995-07-01

    This study calculates source terms released into the environment at the Peach Bottom Atomic Power Station after containment failure during a postulated low-pressure, short-term station blackout severe accident. The severe accident analysis code MELCOR, version 1.8.1, was used in these calculations. Source terms were calculated for three different containment failure modes. The largest environmental releases occur for early containment failure at the drywell liner in contact with the cavity by liner melt-through. This containment failure mode is very likely to occur when the cavity is dry during this postulated severe accident sequence.

  12. Battlefield radiology

    PubMed Central

    Graham, R N J

    2012-01-01

    With the increasing tempo of military conflicts in the last decade, much has been learnt about imaging battlefield casualties in the acute setting. Ultrasound in the form of focused abdominal sonography in trauma (FAST) has proven invaluable in emergency triage of patients for immediate surgery. Multidetector CT allows accurate determination of battlefield trauma injuries. It permits the surgeons and anaesthetists to plan their interventions more thoroughly and to be made aware of clinically occult injuries. There are common injury patterns associated with blast injury, gunshot wounds and blunt trauma. While this body of knowledge is most applicable to the battlefield, there are parallels with peacetime radiology, particularly in terrorist attacks and industrial accidents. This pictorial review is based on the experiences of a UK radiologist deployed in Afghanistan in 2010. PMID:22806621

  13. Primary hypertrophic osteoarthropathy caused by homozygous deletion in HPGD gene in a family: changing clinical and radiological findings with long-term follow-up.

    PubMed

    Tüysüz, Beyhan; Yılmaz, Saliha; Kasapçopur, Özgür; Erener-Ercan, Tuğba; Ceyhun, Emre; Bilguvar, Kaya; Günel, Murat

    2014-11-01

    Autosomal recessive primary hypertrophic osteoarthropathy1 (PHOAR1) is characterized by delayed closure of the fontanels, digital clubbing, arthropathy and periostosis. Homozygous mutations in hydroxyprostaglandin dehydrogenase (HPGD) gene are the underlying pathology of PHOAR1. The aim of this study was to analyze the HPGD gene and the changing clinical and radiological findings with advancing age of two siblings with the diagnosis of PHOAR1. A novel 2-bp homozygous deletion was found in exon 3 (c.310-311delCT) of HPGD gene in the patients. Clinical and radiological findings of the siblings were evaluated between 4 months and 8 years and 6 months of age. The painful swelling and sweating of the hands and feet, cranial ossification defect and expanded diaphyses were evident at infantile period and gradually showed improvement until 4 years of age. After the age of 4 years, digital clubbing and swelling of knees persisted, palmoplantar hyperkeratosis developed and acro-osteolysis became evident on hand radiographs. In conclusion, we suggest that the clinical findings of the patients with PHOAR1 should be classified in two periods as early and late childhood. We also observed that there was intrafamilial variability of clinical findings. PMID:24816859

  14. Global Radiological Source Sorting, Tracking, and Monitoring (Gradsstram) Using Emergin RFID and Web 2.0 Technologies to Provide Total Asset and Information Visualization, Paper at 2009 INMM

    SciTech Connect

    Walker, Randy M.; Kopsick, Deborah A.; Gorman, Bryan L.; Ganguly, Auroop R.; Ferren, Mitch; Shankar, Mallikarjun

    2009-01-01

    Background Thousands of shipments of radioisotopes developed in the United States (U.S.) are transported domestically and internationally for medical and industrial applications, including to partner laboratories in European Union (EU) countries. Over the past five years, the Environmental Protection Agency (EPA), the Department of Energy (DOE), and Oak Ridge National Laboratory (ORNL)1 have worked with state first responder personnel, key private sector supply chain stakeholders, the Department of Homeland Security (DHS), the Department of Transportation (DOT), the Department of Defense (DoD) and the Nuclear Regulatory Commission (NRC) on Radio Frequency Identification (RFID) tracking and monitoring of medical, research and industrial radioisotopes in commerce. ORNL was the pioneer of the international radioisotope shipping and production business. Most radioisotopes made and used today were either made or discovered at ORNL. While most of the radioisotopes used in the commercial sector are now produced and sold by the private market, ORNL still leads the world in the production of exotic, high-value and/or sensitive industrial, medical and research isotopes. The ORNL-EPA-DOE Radiological Source Tracking and Monitoring (RadSTraM) project tested, evaluated, and integrated RFID technologies in laboratory settings and at multiple private-sector shipping and distribution facilities (Perkin Elmer and DHL) to track and monitor common radioisotopes used in everyday commerce. The RFID tracking capability was also tested in association with other deployed technologies including radiation detection, chemical/explosives detection, advanced imaging, lasers, and infrared scanning. At the 2007 EU-U.S. Summit, the leaders of the US Department of Commerce (DOC) and EU European Commission (EC) committed to pursue jointly directed Lighthouse Priority Projects. These projects are intended to foster cooperation and reduce regulatory burdens with respect to transatlantic commerce. The

  15. Long-term fluctuations of hailstorms in South Moravia, Czech Republic: synthesis of different data sources

    NASA Astrophysics Data System (ADS)

    Chromá, Kateřina; Brázdil, Rudolf; Dolák, Lukáš; Řezníčková, Ladislava; Valášek, Hubert; Zahradníček, Pavel

    2016-04-01

    Hailstorms belong to natural phenomena causing great material damage in present time, similarly as it was in the past. In Moravia (eastern part of the Czech Republic), systematic meteorological observations started generally in the latter half of the 19th century. Therefore, in order to create long-term series of hailstorms, it is necessary to search for other sources of information. Different types of documentary evidence are used in historical climatology, such as annals, chronicles, diaries, private letters, newspapers etc. Besides them, institutional documentary evidence of economic and administrative character (e.g. taxation records) has particular importance. This study aims to create a long-term series of hailstorms in South Moravia using various types of documentary evidence (such as taxation records, family archives, chronicles and newspapers which are the most important) and systematic meteorological observations in the station network. Although available hailstorm data cover the 1541-2014 period, incomplete documentary evidence allows reasonable analysis of fluctuations in hailstorm frequency only since the 1770s. The series compiled from documentary data and systematic meteorological observations is used to identify periods of lower and higher hailstorm frequency. Existing data may be used also for the study of spatial hailstorm variability. Basic uncertainties of compiled hailstorm series are discussed. Despite some bias in hailstorm data, South-Moravian hailstorm series significantly extends our knowledge about this phenomenon in the south-eastern part of the Czech Republic. The study is a part of the research project "Hydrometeorological extremes in Southern Moravia derived from documentary evidence" supported by the Grant Agency of the Czech Republic, reg. no. 13-19831S.

  16. Nuclide Importance to Criticality Safety, Decay Heating, and Source Terms Related to Transport and Interim Storage of High-Burnup LWR Fuel

    SciTech Connect

    Gauld, I. C.; Ryman, J. C.

    2000-12-11

    This report investigates trends in the radiological decay properties and changes in relative nuclide importance associated with increasing enrichments and burnup for spent LWR fuel as they affect the areas of criticality safety, thermal analysis (decay heat), and shielding analysis of spent fuel transport and storage casks. To facilitate identifying the changes in the spent fuel compositions that most directly impact these application areas, the dominant nuclides in each area have been identified and ranked by importance. The importance is investigated as a function of increasing burnup to assist in identifying the key changes in spent fuel characteristics between conventional- and extended-burnup regimes. Studies involving both pressurized water-reactor (PWR) fuel assemblies and boiling-water-reactor (BWR) assemblies are included. This study is seen to be a necessary first step in identifying the high-burnup spent fuel characteristics that may adversely affect the accuracy of current computational methods and data, assess the potential impact on previous guidance on isotopic source terms and decay-heat values, and thus help identify areas for methods and data improvement. Finally, several recommendations on the direction of possible future code validation efforts for high-burnup spent fuel predictions are presented.

  17. A Source-Term Based Boundary Layer Bleed/Effusion Model for Passive Shock Control

    NASA Technical Reports Server (NTRS)

    Baurle, Robert A.; Norris, Andrew T.

    2011-01-01

    A modeling framework for boundary layer effusion has been developed based on the use of source (or sink) terms instead of the usual practice of specifying bleed directly as a boundary condition. This framework allows the surface boundary condition (i.e. isothermal wall, adiabatic wall, slip wall, etc.) to remain unaltered in the presence of bleed. This approach also lends itself to easily permit the addition of empirical models for second order effects that are not easily accounted for by simply defining effective transpiration values. Two effusion models formulated for supersonic flows have been implemented into this framework; the Doerffer/Bohning law and the Slater formulation. These models were applied to unit problems that contain key aspects of the flow physics applicable to bleed systems designed for hypersonic air-breathing propulsion systems. The ability of each model to predict bulk bleed properties was assessed, as well as the response of the boundary layer as it passes through and downstream of a porous bleed system. The model assessment was performed with and without the presence of shock waves. Three-dimensional CFD simulations that included the geometric details of the porous plate bleed systems were also carried out to supplement the experimental data, and provide additional insights into the bleed flow physics. Overall, both bleed formulations fared well for the tests performed in this study. However, the sample of test problems considered in this effort was not large enough to permit a comprehensive validation of the models.

  18. On the application of ENO scheme with subcell resolution to conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Chang, Shih-Hung

    1991-01-01

    Two approaches are used to extend the essentially non-oscillatory (ENO) schemes to treat conservation laws with stiff source terms. One approach is the application of the Strang time-splitting method. Here the basic ENO scheme and the Harten modification using subcell resolution (SR), ENO/SR scheme, are extended this way. The other approach is a direct method and a modification of the ENO/SR. Here the technique of ENO reconstruction with subcell resolution is used to locate the discontinuity within a cell and the time evolution is then accomplished by solving the differential equation along characteristics locally and advancing in the characteristic direction. This scheme is denoted ENO/SRCD (subcell resolution - characteristic direction). All the schemes are tested on the equation of LeVeque and Yee (NASA-TM-100075, 1988) modeling reacting flow problems. Numerical results show that these schemes handle this intriguing model problem very well, especially with ENO/SRCD which produces perfect resolution at the discontinuity.

  19. High order finite difference methods with subcell resolution for advection equations with stiff source terms

    SciTech Connect

    Wang, Wei; Shu, Chi-Wang; Yee, H.C.; Sjögreen, Björn

    2012-01-01

    A new high order finite-difference method utilizing the idea of Harten ENO subcell resolution method is proposed for chemical reactive flows and combustion. In reaction problems, when the reaction time scale is very small, e.g., orders of magnitude smaller than the fluid dynamics time scales, the governing equations will become very stiff. Wrong propagation speed of discontinuity may occur due to the underresolved numerical solution in both space and time. The present proposed method is a modified fractional step method which solves the convection step and reaction step separately. In the convection step, any high order shock-capturing method can be used. In the reaction step, an ODE solver is applied but with the computed flow variables in the shock region modified by the Harten subcell resolution idea. For numerical experiments, a fifth-order finite-difference WENO scheme and its anti-diffusion WENO variant are considered. A wide range of 1D and 2D scalar and Euler system test cases are investigated. Studies indicate that for the considered test cases, the new method maintains high order accuracy in space for smooth flows, and for stiff source terms with discontinuities, it can capture the correct propagation speed of discontinuities in very coarse meshes with reasonable CFL numbers.

  20. Semi-implicit and fully implicit shock-capturing methods for hyperbolic conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Shinn, Judy L.

    1987-01-01

    Some numerical aspects of finite-difference algorithms for nonlinear multidimensional hyperbolic conservation laws with stiff nonhomogeneous (source) terms are discussed. If the stiffness is entirely dominated by the source term, a semi-implicit shock-capturing method is proposed provided that the Jacobian of the source terms possesses certain properties. The proposed semi-implicit method can be viewed as a variant of the Bussing and Murman point-implicit scheme with a more appropriate numerical dissipation for the computation of strong shock waves. However, if the stiffness is not solely dominated by the source terms, a fully implicit method would be a better choice. The situation is complicated by problems that are higher than one dimension, and the presence of stiff source terms further complicates the solution procedures for alternating direction implicit (ADI) methods. Several alternatives are discussed. The primary motivation for constructing these schemes was to address thermally and chemically nonequilibrium flows in the hypersonic regime. Due to the unique structure of the eigenvalues and eigenvectors for fluid flows of this type, the computation can be simplified, thus providing a more efficient solution procedure than one might have anticipated.

  1. Maintaining mappings from source systems in a local health information infrastructure.

    PubMed

    Vreeman, Daniel J

    2006-01-01

    We developed a program to assist in managing changes in source system observation terms. The program returns candidate matches based on approximate string comparator scores. A preliminary evaluation of the tool for managing radiology term updates demonstrates its usefulness by identifying exact matches for 61% of new terms and high probability matches for another 25% of new terms. PMID:17238750

  2. Current radiology. Volume 5

    SciTech Connect

    Wilson, G.H.; Hanafee, W.N.

    1984-01-01

    This book contains 10 selections. They are: Nuclear Magnetic Resonance Imaging, Interventional Vascular Radiology, Genitourinary Radiology, Skeletal Radiology, Digital Subtraction Angiography, Neuroradiology, Computed Tomographic Evaluation of Degenerative Diseases of the Lumbar Spine, The Lung, Otolaringology and Opthalmology, and Pediatric Radiology: Cranial, Facial, Cervical, Vertebral, and Appendicular.

  3. Efficient construction of high-resolution TVD conservative schemes for equations with source terms: application to shallow water flows

    NASA Astrophysics Data System (ADS)

    Burguete, J.; García-Navarro, P.

    2001-09-01

    High-resolution total variation diminishing (TVD) schemes are widely used for the numerical approximation of hyperbolic conservation laws. Their extension to equations with source terms involving spatial derivatives is not obvious. In this work, efficient ways of constructing conservative schemes from the conservative, non-conservative or characteristic form of the equations are described in detail. An upwind, as opposed to a pointwise, treatment of the source terms is adopted here, and a new technique is proposed in which source terms are included in the flux limiter functions to get a complete second-order compact scheme. A new correction to fix the entropy problem is also presented and a robust treatment of the boundary conditions according to the discretization used is stated. Copyright

  4. Radiological Control Manual

    SciTech Connect

    Not Available

    1993-04-01

    This manual has been prepared by Lawrence Berkeley Laboratory to provide guidance for site-specific additions, supplements, and clarifications to the DOE Radiological Control Manual. The guidance provided in this manual is based on the requirements given in Title 10 Code of Federal Regulations Part 835, Radiation Protection for Occupational Workers, DOE Order 5480.11, Radiation Protection for Occupational Workers, and the DOE Radiological Control Manual. The topics covered are (1) excellence in radiological control, (2) radiological standards, (3) conduct of radiological work, (4) radioactive materials, (5) radiological health support operations, (6) training and qualification, and (7) radiological records.

  5. Effect of seasonal and long-term changes in stress on sources of water to wells

    USGS Publications Warehouse

    Reilly, Thomas E.; Pollock, David W.

    1995-01-01

    The source of water to wells is ultimately the location where the water flowing to a well enters the boundary surface of the ground-water system . In ground-water systems that receive most of their water from areal recharge, the location of the water entering the system is at the water table . The area contributing recharge to a discharging well is the surface area that defines the location of the water entering the groundwater system. Water entering the system at the water table flows to the well and is eventually discharged from the well. Many State agencies are currently (1994) developing wellhead-protection programs. The thrust of some of these programs is to protect water supplies by determining the areas contributing recharge to water-supply wells and by specifying regulations to minimize the opportunity for contamination of the recharge water by activities at the land surface. In the analyses of ground-water flow systems, steady-state average conditions are frequently used to simplify the problem and make a solution tractable. Recharge is usually cyclic in nature, however, having seasonal cycles and longer term climatic cycles. A hypothetical system is quantitatively analyzed to show that, in many cases, these cyclic changes in the recharge rates apparently do not significantly affect the location and size of the areas contributing recharge to wells. The ratio of the mean travel time to the length of the cyclic stress period appears to indicate whether the transient effects of the cyclic stress must be explicitly represented in the analysis of contributing areas to wells. For the cases examined, if the ratio of the mean travel time to the period of the cyclic stress was much greater than one, then the transient area contributing recharge to wells was similar to the area calculated using an average steady-state condition. Noncyclic long-term transient changes in water use, however, and cyclic stresses on systems with ratios less than 1 can and do affect the

  6. Analysis of accident sequences and source terms at waste treatment and storage facilities for waste generated by U.S. Department of Energy Waste Management Operations, Volume 3: Appendixes C-H

    SciTech Connect

    Mueller, C.; Nabelssi, B.; Roglans-Ribas, J.

    1995-04-01

    This report contains the Appendices for the Analysis of Accident Sequences and Source Terms at Waste Treatment and Storage Facilities for Waste Generated by the U.S. Department of Energy Waste Management Operations. The main report documents the methodology, computational framework, and results of facility accident analyses performed as a part of the U.S. Department of Energy (DOE) Waste Management Programmatic Environmental Impact Statement (WM PEIS). The accident sequences potentially important to human health risk are specified, their frequencies are assessed, and the resultant radiological and chemical source terms are evaluated. A personal computer-based computational framework and database have been developed that provide these results as input to the WM PEIS for calculation of human health risk impacts. This report summarizes the accident analyses and aggregates the key results for each of the waste streams. Source terms are estimated and results are presented for each of the major DOE sites and facilities by WM PEIS alternative for each waste stream. The appendices identify the potential atmospheric release of each toxic chemical or radionuclide for each accident scenario studied. They also provide discussion of specific accident analysis data and guidance used or consulted in this report.

  7. Semi-implicit and fully implicit shock-capturing methods for hyperbolic conservation laws with stiff source terms

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Shinn, J. L.

    1986-01-01

    Some numerical aspects of finite-difference algorithms for nonlinear multidimensional hyperbolic conservation laws with stiff nonhomogenous (source) terms are discussed. If the stiffness is entirely dominated by the source term, a semi-implicit shock-capturing method is proposed provided that the Jacobian of the soruce terms possesses certain properties. The proposed semi-implicit method can be viewed as a variant of the Bussing and Murman point-implicit scheme with a more appropriate numerical dissipation for the computation of strong shock waves. However, if the stiffness is not solely dominated by the source terms, a fully implicit method would be a better choice. The situation is complicated by problems that are higher than one dimension, and the presence of stiff source terms further complicates the solution procedures for alternating direction implicit (ADI) methods. Several alternatives are discussed. The primary motivation for constructing these schemes was to address thermally and chemically nonequilibrium flows in the hypersonic regime. Due to the unique structure of the eigenvalues and eigenvectors for fluid flows of this type, the computation can be simplified, thus providing a more efficient solution procedure than one might have anticipated.

  8. The development of a realistic source term for sodium-cooled fast reactors : assessment of current status and future needs.

    SciTech Connect

    LaChance, Jeffrey L.; Phillips, Jesse; Parma, Edward J., Jr.; Olivier, Tara Jean; Middleton, Bobby D.

    2011-06-01

    Sodium-cooled fast reactors (SFRs) continue to be proposed and designed throughout the United States and the world. Although the number of SFRs actually operating has declined substantially since the 1980s, a significant interest in advancing these types of reactor systems remains. Of the many issues associated with the development and deployment of SFRs, one of high regulatory importance is the source term to be used in the siting of the reactor. A substantial amount of modeling and experimental work has been performed over the past four decades on accident analysis, sodium coolant behavior, and radionuclide release for SFRs. The objective of this report is to aid in determining the gaps and issues related to the development of a realistic, mechanistically derived source term for SFRs. This report will allow the reader to become familiar with the severe accident source term concept and gain a broad understanding of the current status of the models and experimental work. Further, this report will allow insight into future work, in terms of both model development and experimental validation, which is necessary in order to develop a realistic source term for SFRs.

  9. [Personal computer interactive algorithm for estimating radiologic contamination and doses after a nuclear accident in Europe].

    PubMed

    Tabet, E

    2001-01-01

    The algorithm RANA (radiological assessment of nuclear accidents) is a tool which can be exploited to estimate the space and time structure of the radiological consequences of a radioactive release following a nuclear accident in Europe. The algorithm, formulated in the language of Mathematica, can be run on a personal computer. It uses simplified physical assumptions as for the the diffusion of the cloud and the transfer of the contamination to the food chain. The user gets the needed information by means of interactive windows that allow a fast evaluation of dose and contamination profiles. Calculations are performed either starting from the source terms or from the knowledge of experimental contamination data. Radiological consequences, such as individual or collective doses from several exposure paths, are parametrized in terms of the atmospheric diffusion categories. PMID:11758278

  10. Development of Approach for Long-Term Management of Disused Sealed Radioactive Sources - 13630

    SciTech Connect

    Kinker, M.; Reber, E.; Mansoux, H.; Bruno, G.

    2013-07-01

    Radioactive sources are used widely throughout the world in a variety of medical, industrial, research and military applications. When such radioactive sources are no longer used and are not intended to be used for the practice for which an authorization was granted, they are designated as 'disused sources'. Whether appropriate controls are in place during the useful life of a source or not, the end of this useful life is often a turning point after which it is more difficult to ensure the safety and security of the source over time. For various reasons, many disused sources cannot be returned to the manufacturer or the supplier for reuse or recycling. When these attempts fail, disused sources should be declared as radioactive waste and should be managed as such, in compliance with relevant international legal instruments and safety standards. However, disposal remains an unresolved issue in many counties, due to in part to limited public acceptance, insufficient funding, and a lack of practical examples of strategies for determining suitable disposal options. As a result, disused sources are often stored indefinitely at the facilities where they were once used. In order to prevent disused sources from becoming orphan sources, each country must develop and implement a comprehensive waste management strategy that includes disposal of disused sources. The International Atomic Energy Agency (IAEA) fosters international cooperation between countries and encourages the development of a harmonized 'cradle to grave' approach to managing sources consistent with international legal instruments, IAEA safety standards, and international good practices. This 'cradle to grave' approach requires the development of a national policy and implementing strategy, an adequate legal and regulatory framework, and adequate resources and infrastructure that cover the entire life cycle, from production and use of radioactive sources to disposal. (authors)

  11. Quantitative assessment of seismic source performance: Feasibility of small and affordable seismic sources for long term monitoring at the Ketzin CO2 storage site, Germany

    NASA Astrophysics Data System (ADS)

    Sopher, Daniel; Juhlin, Christopher; Huang, Fei; Ivandic, Monika; Lueth, Stefan

    2014-08-01

    We apply a range of quantitative pre-stack analysis techniques to assess the feasibility of using smaller and cheaper seismic sources, than those currently used at the Ketzin CO2 storage site. Results from two smaller land sources are presented alongside those from a larger, more powerful source, typically utilized for seismic acquisition at the Ketzin. The geological target for the study is the Triassic Stuttgart Formation which contains a saline aquifer currently used for CO2 storage. The reservoir lies at a depth of approximately 630 m, equivalent to a travel time of 500 ms along the study profile. The three sources discussed in the study are the Vibsist 3000, Vibsist 500 (using industrial hydraulic driven concrete breaking hammers) and a drop hammer source. Data were collected for the comparison using the three sources in 2011, 2012 and 2013 along a 984 m long line with 24 m receiver spacing and 12 m shot spacing. Initially a quantitative analysis is performed of the noise levels between the 3 surveys. The raw shot gathers are then analyzed quantitatively to investigate the relative energy output, signal to noise ratio, penetration depth, repeatability and frequency content for the different sources. The performance of the sources is also assessed based on stacked seismic sections. Based on the results from this study it appears that both of the smaller sources are capable of producing good images of the target reservoir and can both be considered suitable as lower cost, less invasive sources for use at the Ketzin site or other shallow CO2 storage projects. Finally, the results from the various pre-stack analysis techniques are discussed in terms of how representative they are of the final stacked sections.

  12. Nonradioactive Environmental Emissions Chemical Source Term for the Double Shell Tank (DST) Vapor Space During Waste Retrieval Operations

    SciTech Connect

    MAY, T.H.

    2000-04-21

    A nonradioactive chemical vapor space source term for tanks on the Phase 1 and the extended Phase 1 delivery, storage, and disposal mission was determined. Operations modeled included mixer pump operation and DST waste transfers. Concentrations of ammonia, specific volatile organic compounds, and quantitative volumes of aerosols were estimated.

  13. Use of WIMS-E lattice code for prediction of the transuranic source term for spent fuel dose estimation

    SciTech Connect

    Schwinkendorf, K.N.

    1996-04-15

    A recent source term analysis has shown a discrepancy between ORIGEN2 transuranic isotopic production estimates and those produced with the WIMS-E lattice physics code. Excellent agreement between relevant experimental measurements and WIMS-E was shown, thus exposing an error in the cross section library used by ORIGEN2.

  14. Hanford tank residual waste – contaminant source terms and release models

    SciTech Connect

    Deutsch, William J.; Cantrell, Kirk J.; Krupka, Kenneth M.; Lindberg, Michael J.; Serne, R. Jeffrey

    2011-08-23

    Residual waste is expected to be left in 177 underground storage tanks after closure at the U.S. Department of Energy’s Hanford Site in Washington State (USA). In the long term, the residual wastes represent a potential source of contamination to the subsurface environment. Residual materials that cannot be completely removed during the tank closure process are being studied to identify and characterize the solid phases and estimate the release of contaminants from these solids to water that might enter the closed tanks in the future. As of the end of 2009, residual waste from five tanks has been evaluated. Residual wastes from adjacent tanks C-202 and C-203 have high U concentrations of 24 and 59 wt%, respectively, while residual wastes from nearby tanks C-103 and C-106 have low U concentrations of 0.4 and 0.03 wt%, respectively. Aluminum concentrations are high (8.2 to 29.1 wt%) in some tanks (C-103, C-106, and S-112) and relatively low (<1.5 wt%) in other tanks (C-202 and C-203). Gibbsite is a common mineral in tanks with high Al concentrations, while non-crystalline U-Na-C-O-P±H phases are common in the U-rich residual wastes from tanks C-202 and C-203. Iron oxides/hydroxides have been identified in all residual waste samples studied to date. Contaminant release from the residual wastes was studied by conducting batch leach tests using distilled deionized water, a Ca(OH)2-saturated solution, or a CaCO3-saturated water. Uranium release concentrations are highly dependent on waste and leachant compositions with dissolved U concentrations one or two orders of magnitude higher in the tests with high U residual wastes, and also higher when leached with the CaCO3-saturated solution than with the Ca(OH)2-saturated solution. Technetium leachability is not as strongly dependent on the concentration of Tc in the waste, and it appears to be slightly more leachable by the Ca(OH)2-saturated solution than by the CaCO3-saturated solution. In general, Tc is much less

  15. Observational manifestations and intrinsic properties of the RCR sources in terms of a unified model

    NASA Astrophysics Data System (ADS)

    Zhelenkova, O. P.; Majorova, E. K.

    2016-04-01

    We present a summary results of the study of radio sources showing significant variations of integral flux density using the data from the RATAN-600 surveys of 1980-1994 at a frequency of 7.6 cm. The majority of the detected variable sources have flat radio spectra, although there are also all other spectrum types found. Point and compact sources predominate, although all known morphological structures are found in the sample. Variability is detected both in quasars and galaxies. Using the catalog data, we found brightness variations in the optical and/or infrared ranges for a half of host objects of radio sources. We analyzed the properties of nonvariable and variable RCR sources. We compared the ratio of absolute magnitude to radio luminosity for sources with the active nucleus types determined from the optical data. It is found that this parameter is approximately the same for quasars with different radio luminosity. It isminimum for the strongest radio galaxies and grows up to the level characteristic of quasars with the decrease of radio luminosity. Considering that the ratio depends on obscuring properties of a dust torus, such behavior can be explained if we assume that the torus geometry and its optical depth depend on the source long. This parameter is slightly higher among variable sources than among nonvariable ones which counts in favor of the nucleus more open to an observer.

  16. Benchmarking the New RESRAD-OFFSITE Source Term Model with DUST-MS and GoldSim - 13377

    SciTech Connect

    Cheng, J.J.; Kamboj, S.; Gnanapragasam, E.; Yu, C.

    2013-07-01

    RESRAD-OFFSITE is a computer code developed by Argonne National Laboratory under the sponsorship of U.S. Department of Energy (DOE) and U.S. Nuclear Regulatory Commission (NRC). It is designed on the basis of RESRAD (onsite) code, a computer code designated by DOE and NRC for evaluating soil-contaminated sites for compliance with human health protection requirements pertaining to license termination or environmental remediation. RESRAD-OFFSITE has enhanced capabilities of modeling radionuclide transport to offsite locations and calculating potential radiation exposure to offsite receptors. Recently, a new source term model was incorporated into RESRAD-OFFSITE to enhance its capability further. This new source term model allows simulation of radionuclide releases from different waste forms, in addition to the soil sources originally considered in RESRAD (onsite) and RESRAD-OFFSITE codes. With this new source term model, a variety of applications can be achieved by using RESRAD-OFFSITE, including but not limited to, assessing the performance of radioactive waste disposal facilities. This paper presents the comparison of radionuclide release rates calculated by the new source term model of RESRAD-OFFSITE versus those calculated by DUST-MS and GoldSim, respectively. The focus of comparison is on the release rates of radionuclides from the bottom of the contaminated zone that was assumed to contain radioactive source materials buried in soil. The transport of released contaminants outside of the primary contaminated zone is beyond the scope of this paper. Overall, the agreement between the RESRAD-OFFSITE results and the DUST-MS and GoldSim results is fairly good, with all three codes predicting identical or similar radionuclide release profiles over time. Numerical dispersion in the DUST-MS and GoldSim results was identified as potentially contributing to the disagreement in the release rates. In general, greater discrepancy in the release rates was found for short

  17. Detailed source term estimation of atmospheric release during the Fukushima Dai-ichi nuclear power plant accident by coupling atmospheric and oceanic dispersion models

    NASA Astrophysics Data System (ADS)

    Katata, Genki; Chino, Masamichi; Terada, Hiroaki; Kobayashi, Takuya; Ota, Masakazu; Nagai, Haruyasu; Kajino, Mizuo

    2014-05-01

    Temporal variations of release amounts of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident and their dispersion process are essential to evaluate the environmental impacts and resultant radiological doses to the public. Here, we estimated a detailed time trend of atmospheric releases during the accident by combining environmental monitoring data and coupling atmospheric and oceanic dispersion simulations by WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN developed by the authors. New schemes for wet, dry, and fog depositions of radioactive iodine gas (I2 and CH3I) and other particles (I-131, Te-132, Cs-137, and Cs-134) were incorporated into WSPEEDI-II. The deposition calculated by WSPEEDI-II was used as input data of ocean dispersion calculations by SEA-GEARN. The reverse estimation method based on the simulation by both models assuming unit release rate (1 Bq h-1) was adopted to estimate the source term at the FNPP1 using air dose rate, and air sea surface concentrations. The results suggested that the major release of radionuclides from the FNPP1 occurred in the following periods during March 2011: afternoon on the 12th when the venting and hydrogen explosion occurred at Unit 1, morning on the 13th after the venting event at Unit 3, midnight on the 14th when several openings of SRV (steam relief valve) were conducted at Unit 2, morning and night on the 15th, and morning on the 16th. The modified WSPEEDI-II using the newly estimated source term well reproduced local and regional patterns of air dose rate and surface deposition of I-131 and Cs-137 obtained by airborne observations. Our dispersion simulations also revealed that the highest radioactive contamination areas around FNPP1 were created from 15th to 16th March by complicated interactions among rainfall (wet deposition), plume movements, and phase properties (gas or particle) of I-131 and release rates

  18. Long Term Temporal and Spectral Evolution of Point Sources in Nearby Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Durmus, D.; Guver, T.; Hudaverdi, M.; Sert, H.; Balman, Solen

    2016-06-01

    We present the results of an archival study of all the point sources detected in the lines of sight of the elliptical galaxies NGC 4472, NGC 4552, NGC 4649, M32, Maffei 1, NGC 3379, IC 1101, M87, NGC 4477, NGC 4621, and NGC 5128, with both the Chandra and XMM-Newton observatories. Specifically, we studied the temporal and spectral evolution of these point sources over the course of the observations of the galaxies, mostly covering the 2000 - 2015 period. In this poster we present the first results of this study, which allows us to further constrain the X-ray source population in nearby elliptical galaxies and also better understand the nature of individual point sources.

  19. Radiological health

    SciTech Connect

    Barnes, C.M.

    1981-12-01

    Dosimeters were provided for development within the crew compartment and on the astronauts flight garments to detect radiation encountered by the space crew during the mission. The STS-1 mission encountered geomagnetically trapped electrons and protons on 13 low altitude passes through the South Atlantic anomaly. The orbital inclination was such that encounters with the outer belt horn was negligible. Radiation dose to the crew from the above events was estimated to be 5 millirad. Total PDL measured dose to the crew from all sources during the STS-1 mission was 20 millirad.

  20. Common Interventional Radiology Procedures

    MedlinePlus

    ... of common interventional techniques is below. Common Interventional Radiology Procedures Angiography An X-ray exam of the ... into the vertebra. Copyright © 2016 Society of Interventional Radiology. All rights reserved. 3975 Fair Ridge Drive • Suite ...

  1. Emergency preparedness source term development for the Office of Nuclear Material Safety and Safeguards-Licensed Facilities

    SciTech Connect

    Sutter, S.L.; Mishima, J.; Ballinger, M.Y.; Lindsey, C.G.

    1984-08-01

    In order to establish requirements for emergency preparedness plans at facilities licensed by the Office of Nuclear Materials Safety and Safeguards, the Nuclear Regulatory Commission (NRC) needs to develop source terms (the amount of material made airborne) in accidents. These source terms are used to estimate the potential public doses from the events, which, in turn, will be used to judge whether emergency preparedness plans are needed for a particular type of facility. Pacific Northwest Laboratory is providing the NRC with source terms by developing several accident scenarios for eleven types of fuel cycle and by-product operations. Several scenarios are developed for each operation, leading to the identification of the maximum release considered for emergency preparedness planning (MREPP) scenario. The MREPP scenarios postulated were of three types: fire, tornado, and criticality. Fire was significant at oxide fuel fabrication, UF/sub 6/ production, radiopharmaceutical manufacturing, radiopharmacy, sealed source manufacturing, waste warehousing, and university research and development facilities. Tornadoes were MREPP events for uranium mills and plutonium contaminated facilities, and criticalities were significant at nonoxide fuel fabrication and nuclear research and development facilities. Techniques for adjusting the MREPP release to different facilities are also described.

  2. Using natural archives to track sources and long-term trends of pollution: an introduction

    USGS Publications Warehouse

    Jules Blais; Rosen, Michael R.; John Smol

    2015-01-01

    This book explores the myriad ways that environmental archives can be used to study the distribution and long-term trajectories of contaminants. The volume first focuses on reviews that examine the integrity of the historic record, including factors related to hydrology, post-depositional diffusion, and mixing processes. This is followed by a series of chapters dealing with the diverse archives available for long-term studies of environmental pollution.

  3. Mobile computing for radiology.

    PubMed

    Auffermann, William F; Chetlen, Alison L; Sharma, Arjun; Colucci, Andrew T; DeQuesada, Ivan M; Grajo, Joseph R; Kung, Justin W; Loehfelm, Thomas W; Sherry, Steven J

    2013-12-01

    The rapid advances in mobile computing technology have the potential to change the way radiology and medicine as a whole are practiced. Several mobile computing advances have not yet found application to the practice of radiology, while others have already been applied to radiology but are not in widespread clinical use. This review addresses several areas where radiology and medicine in general may benefit from adoption of the latest mobile computing technologies and speculates on potential future applications. PMID:24200475

  4. Group analysis of the Fourier transform of the spatially homogeneous and isotropic Boltzmann equation with a source term

    NASA Astrophysics Data System (ADS)

    Suriyawichitseranee, A.; Grigoriev, Yu. N.; Meleshko, S. V.

    2015-03-01

    The paper is devoted to group analysis of the spatially homogeneous and isotropic Boltzmann equation with a source term. In fact, the Fourier transform of the Boltzmann equation with respect to the molecular velocity variable is considered. Using a particular class of solutions, the determining equation for the admitted Lie group is reduced to a partial differential equation for the source function. The latter equation is analyzed by an algebraic method. A complete group classification of the Fourier transform of the Boltzmann equation is given. All invariant solutions of this equation are also presented in the paper.

  5. Long term monitoring of extragalactic sources in the framework of the Gaia ESA mission

    NASA Astrophysics Data System (ADS)

    TARIS, François

    2015-08-01

    The Gaia astrometric mission of the European Space Agency has been launched the 19th December 2013. It will provide an astrometric catalogue of 500.000 extragalactic sources that could be the basis of a new optical reference frame after the Hipparcos satellite one. On the other hand, the current International Celestial Reference Frame (ICRF) is based on the observations of extragalactic sources at radio wavelength. The astrometric coordinates of sources in these two reference systems will have roughly the same uncertainty. It is then mandatory to observe a set of common targets at both optical and radio wavelength to link the ICRF with what could be called the GCRF (Gaia Celestial Reference Frame).This poster presents the set of optical telescopes used to observe the targets chosen for the link of the two reference systems.It also presents some results obtained with the Lomb-Scargle method and CLEAN algorithm applied to optical magnitude monitoring of extragalactic sources suitable for the GCRF-ICRF link. These two methods allow to show that some periodic (or quasi-periodic) phenomena could be present and could be at the origin of the observed light curves. This could have an important impact on the photocenter's position of a particular target which is relevant for the link of the reference systems.

  6. Long-term studies with the Ariel 5 ASM. 2: The strong Cygnus sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. J.

    1979-01-01

    The three bright 3-6 keV X-ray sources in Cygnus are examined for regular temporal variability with a 1300-day record from the Ariel 5 All Sky Monitor. The only periods consistently observed are 5.6 days for Cyg X-1, 11.23 days for Cyg X-2, and 4.8 hours for Cyg X-3.

  7. Measurement and apportionment of radon source terms for modeling indoor environments

    SciTech Connect

    Harley, N.H.

    1990-01-01

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters.

  8. Interpretation of features in the cosmic ray proton and helium energy spectra in terms of a local source

    NASA Astrophysics Data System (ADS)

    Erlykin, A. D.; Wolfendale, A. W.

    2015-12-01

    Recent measurements using the AMS-02 cosmic ray (CR) spectrometer have shown structure in the spectra of protons and helium nuclei, structure that had been seen earlier but with lower precision. We interpret the measurements in terms of there having been an important contribution from a local supernova from which CRs have diffused to Earth. The characteristics of the source make it likely to be the same as that responsible for the structure in the positron and antiproton spectra.

  9. EVALUATION OF SHORT-TERM NO2 PLUME MODELS FOR POINT SOURCES. VOLUME 1: TECHNICAL DISCUSSION

    EPA Science Inventory

    Models for predicting short-term NO2 concentrations are discussed, and several (RPM-II, TCM, OLM, and CNOM) are selected for evaluation. The MISTT data, collected in 1976, were to be used to evaluate the models, but careful scrutiny of the data base revealed certain deficiencies ...

  10. Estimation of the SO2 source term for the Holuhraun event and its influence on central Europe air quality

    NASA Astrophysics Data System (ADS)

    Arnold, Delia; Iren Kristiansen, Nina; Theys, Nicolas; Brenot, Hugues; Maurer, Christian; Wotawa, Gerhard; Stebel, Kerstin; Holla, Robert; Gilge, Stefan; Flemming, Johannes; Stohl, Andreas; Hirtl, Marcus

    2015-04-01

    On 29 August 2014 a fissure eruption began in Holuhraun, Northeastern Iceland, associated with increased volcanic activity in the Bárdarbunga system. For more than 150 days, the eruption released large quantities of SO2 into the atmosphere affecting not only the local Icelandic air quality, but also leading to periods of increased ambient SO2 concentrations in parts of mainland Europe. During the second half of September, significant amounts of SO2 were rapidly transported southward by favourable meteorological conditions and several countries in Central Europe experienced high ground-level SO2 concentrations. The measured concentrations reached and even exceeded the EC directive health thresholds. In this work, we evaluate the air quality effects in Europe during this targeted period using both ground-based and satellite observations (GOME2B and OMI) as well as dispersion modelling with the Lagrangian particle model FLEXPART. We estimate the volcanic SO2 source emissions by comparing the satellite observations with atmospheric transport model simulations in an inverse modelling approach. The estimated source term is evaluated against independent ground-based observational data (e.g. MAX-DOAS, Brewer) and used as emission term in dispersion model forecasts for evaluating the air quality effects in Europe. In addition, the potential use of air quality data to perform the source term estimation by inversion with ground-based data will also be investigated.

  11. Development of a new long term multiple-source plume model: Application on some industrial and residential areas in Kuwait

    SciTech Connect

    Ahmad, N.; Bouhamra, W. )

    1993-05-01

    A long term plume model, which is based on the Gaussian dispersion equation, has been developed for computing pollutant concentrations from multiple sources of different heights and emission rates. Unlike the conventional multiple-source models, the summation or integration of the concentrations of all point sources is not needed in the new model. Instead, the properties (height, diameter, location, etc.) and the emission variables (gas velocity, temperature, flow rates, etc.) of the different stacks, or point sources, are presented by a single stack. These properties and emission variables of the [open quotes]superstack[close quotes] are obtained by using the concept of the mixing rule of multi-component systems. Consequently, the problem becomes finding the concentration of a single point source which drastically reduces the computations involved in the conventional multiple-source models. The new model gave a better prediction of SO[sub 2] concentration than the conventional model. The results also showed that there are two different trends in the dispersion of this pollutant. 15 refs., 6 figs., 1 tab.

  12. In-stream attenuation of nitrogen and phosphorus from major point source in large-scale watershed: mixed source and long-term variation

    NASA Astrophysics Data System (ADS)

    Chen, X.; Fulda, M.; Keller, A. A.

    2011-12-01

    Increased human activity in agriculture and industry has posed significant impact on natural water bodies and resulted in water quality deterioration. Agricultural non-point source pollution and urban point source discharge from municipal waste water treatment plant are the more recent concerns. Computer models are often used to help assess the fate and transport of pollutant, which involves complex interactions such as adsorption, biochemical reaction and plants uptake. However, it remains to be a challenge to assess the attenuation of total nitrogen and total phosphorus in large-scale watershed where there are significant difference in land use types and soil properties, especially when there are significant temporal variations through a long-term simulation. In this study, a large-scale watershed model in the Ohio River Basin was constructed considering a ten year simulation period. To assess the downstream impacts of increasing or decreasing nutrient loads, a hypothetical waste water treatment plant was added as the point source in different subwatersheds, monitoring the downstream effects. Five scenarios (100 kg/d Ammonia, 100 kg/d Nitrate, 100 kg/d Phosphate, mixed 100 kg/d Ammonia & 100 kg/d Phosphate and mixed 100 kg/d Nitrate & 100 kg/d Phosphate) were examined to assess the attenuation process throughout the 10-years simulation. In addition to significant differences in the attenuation in different subwatersheds, the various loads had complex interrelations. We also observed significant variations in attenuation for short-term simulation, while in long-term, the attenuation factors tended to be stabilized.

  13. CDC Grand Rounds: radiological and nuclear preparedness.

    PubMed

    2010-09-17

    Radiological and nuclear disasters are infrequent, but when they occur, they result in large and demonstrable health burdens. Several scenarios can result in the public's exposure to radiation. For example, radiation sources used in health care or other industries can be lost or misused. Incidents in the nuclear power industry, such as those at Chernobyl and Three Mile Island, require significant public health response. In addition, radiological terrorism can involve the use of a radiological dispersal device (RDD) or an improvised nuclear device (IND). State and local health agencies are expected to perform essential public health functions in response to any of these emergencies. PMID:20847721

  14. Bioaerosol releases from compost facilities: Evaluating passive and active source terms at a green waste facility for improved risk assessments

    NASA Astrophysics Data System (ADS)

    Taha, M. P. M.; Drew, G. H.; Longhurst, P. J.; Smith, R.; Pollard, S. J. T.

    The passive and active release of bioaerosols during green waste composting, measured at source is reported for a commercial composting facility in South East (SE) England as part of a research programme focused on improving risk assessments at composting facilities. Aspergillus fumigatus and actinomycetes concentrations of 9.8-36.8×10 6 and 18.9-36.0×10 6 cfu m -3, respectively, measured during the active turning of green waste compost, were typically 3-log higher than previously reported concentrations from static compost windrows. Source depletion curves constructed for A. fumigatus during compost turning and modelled using SCREEN3 suggest that bioaerosol concentrations could reduce to background concentrations of 10 3 cfu m -3 within 100 m of this site. Authentic source term data produced from this study will help to refine the risk assessment methodologies that support improved permitting of compost facilities.

  15. Shielding analysis of proton therapy accelerators: a demonstration using Monte Carlo-generated source terms and attenuation lengths.

    PubMed

    Lai, Bo-Lun; Sheu, Rong-Jiun; Lin, Uei-Tyng

    2015-05-01

    Monte Carlo simulations are generally considered the most accurate method for complex accelerator shielding analysis. Simplified models based on point-source line-of-sight approximation are often preferable in practice because they are intuitive and easy to use. A set of shielding data, including source terms and attenuation lengths for several common targets (iron, graphite, tissue, and copper) and shielding materials (concrete, iron, and lead) were generated by performing Monte Carlo simulations for 100-300 MeV protons. Possible applications and a proper use of the data set were demonstrated through a practical case study, in which shielding analysis on a typical proton treatment room was conducted. A thorough and consistent comparison between the predictions of our point-source line-of-sight model and those obtained by Monte Carlo simulations for a 360° dose distribution around the room perimeter showed that the data set can yield fairly accurate or conservative estimates for the transmitted doses, except for those near the maze exit. In addition, this study demonstrated that appropriate coupling between the generated source term and empirical formulae for radiation streaming can be used to predict a reasonable dose distribution along the maze. This case study proved the effectiveness and advantage of applying the data set to a quick shielding design and dose evaluation for proton therapy accelerators. PMID:25811254

  16. A Multigroup Method for the Calculation of Neutron Fluence with a Source Term

    NASA Technical Reports Server (NTRS)

    Heinbockel, J. H.; Clowdsley, M. S.

    1998-01-01

    Current research on the Grant involves the development of a multigroup method for the calculation of low energy evaporation neutron fluences associated with the Boltzmann equation. This research will enable one to predict radiation exposure under a variety of circumstances. Knowledge of radiation exposure in a free-space environment is a necessity for space travel, high altitude space planes and satellite design. This is because certain radiation environments can cause damage to biological and electronic systems involving both short term and long term effects. By having apriori knowledge of the environment one can use prediction techniques to estimate radiation damage to such systems. Appropriate shielding can be designed to protect both humans and electronic systems that are exposed to a known radiation environment. This is the goal of the current research efforts involving the multi-group method and the Green's function approach.

  17. Preservation of nutrients during long-term storage of source-separated yellowwater.

    PubMed

    Paruch, Adam M

    2012-01-01

    Source separation of human urine (yellowwater) enhances the sustainability of wastewater management and efficiency of nutrient recovery and recycling. Storage of source-separated yellowwater is recommended prior to agronomic reuse. At this point, it is of immense interest to determine the effect of storage time on quality of yellowwater. Therefore, this study focused on examining changes in some chemical properties of raw, undiluted, freshly collected, source-separated yellowwater stored for a period of 1 year under different temperature regimes: cold (4 °C), mild (10 °C) and warm (22 °C). Chemical parameters (biochemical oxygen demand (BOD(5)), N-tot, N-NO(2), N-NO(3), N-NH(4), P-tot, K, S, and pH), with the main focus on fertiliser nutrient compounds intended for agricultural utilisation, were tested. The outcomes revealed that both nitrification and denitrification processes took place in the stored yellowwater, and an increase in the pH level of up to pH greater than 9 was observed. The study found that the main macronutrients can be well preserved in yellowwater, as there were no substantial changes in the contents of these elements over a 1 year storage period at the three temperatures tested. PMID:22766870

  18. Environmental and radiological safety studies. Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 25, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1981-11-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  19. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, April 1- June 30, 1982

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.; Stalnaker, N.D.

    1982-09-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources on terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  20. Environmental and radiological safety studies: Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, September 26-December 25, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1982-02-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effect of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  1. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 30, 1982

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.; Stalnaker, N.D.

    1982-12-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  2. Long-Term Optical/X-ray Variability of CVs, LMXBs and BeX Sources

    NASA Astrophysics Data System (ADS)

    Charles, Phil; Kotze, Marissa; Rajoelimanana, Andry

    2010-12-01

    The study of long-term variability of interacting binaries has been revolutionised at X-ray and optical wavelengths by RXTE's all-sky monitor, combined with ground-based wide-field optical monitoring of the Magellanic Clouds and galactic bulge regions. We present a summary of long-term, super-orbital X-ray modulations detected in luminous galactic X-ray binaries, with particular emphasis on the recently identified multi-year modulations which may be related to solar-cycle-like variations in the low-mass donor stars. The MACHO and OGLE databases of SMC optical monitoring have revealed long-term (200-3000 d) variations in BeX systems that we propose are a function of the formation and depletion of the rapidly-rotating Be star's equatorial disc. We compile a list of the 7 different types of super-orbital modulations now identified in interacting binaries, based on their observed characteristics and likely physical origin.

  3. Nodal Green’s Function Method Singular Source Term and Burnable Poison Treatment in Hexagonal Geometry

    SciTech Connect

    A.A. Bingham; R.M. Ferrer; A.M. ougouag

    2009-09-01

    An accurate and computationally efficient two or three-dimensional neutron diffusion model will be necessary for the development, safety parameters computation, and fuel cycle analysis of a prismatic Very High Temperature Reactor (VHTR) design under Next Generation Nuclear Plant Project (NGNP). For this purpose, an analytical nodal Green’s function solution for the transverse integrated neutron diffusion equation is developed in two and three-dimensional hexagonal geometry. This scheme is incorporated into HEXPEDITE, a code first developed by Fitzpatrick and Ougouag. HEXPEDITE neglects non-physical discontinuity terms that arise in the transverse leakage due to the transverse integration procedure application to hexagonal geometry and cannot account for the effects of burnable poisons across nodal boundaries. The test code being developed for this document accounts for these terms by maintaining an inventory of neutrons by using the nodal balance equation as a constraint of the neutron flux equation. The method developed in this report is intended to restore neutron conservation and increase the accuracy of the code by adding these terms to the transverse integrated flux solution and applying the nodal Green’s function solution to the resulting equation to derive a semi-analytical solution.

  4. Relative contribution of DNAPL dissolution and matrix diffusion to the long-term persistence of chlorinated solvent source zones

    NASA Astrophysics Data System (ADS)

    Seyedabbasi, Mir Ahmad; Newell, Charles J.; Adamson, David T.; Sale, Thomas C.

    2012-06-01

    The relative contribution of dense non-aqueous phase liquid (DNAPL) dissolution versus matrix diffusion processes to the longevity of chlorinated source zones was investigated. Matrix diffusion is being increasingly recognized as an important non-DNAPL component of source behavior over time, and understanding the persistence of contaminants that have diffused into lower permeability units can impact remedial decision-making. In this study, a hypothetical DNAPL source zone architecture consisting of several different sized pools and fingers originally developed by Anderson et al. (1992) was adapted to include defined low permeability layers. A coupled dissolution-diffusion model was developed to allow diffusion into these layers while in contact with DNAPL, followed by diffusion out of these same layers after complete DNAPL dissolution. This exercise was performed for releases of equivalent masses (675 kg) of three different compounds, including chlorinated solvents with solubilities ranging from low (tetrachloroethene (PCE)), moderate (trichloroethene (TCE)) to high (dichloromethane (DCM)). The results of this simple modeling exercise demonstrate that matrix diffusion can be a critical component of source zone longevity and may represent a longer-term contributor to source longevity (i.e., longer time maintaining concentrations above MCLs) than DNAPL dissolution alone at many sites. For the hypothetical TCE release, the simulation indicated that dissolution of DNAPL would take approximately 38 years, while the back diffusion from low permeability zones could maintain the source for an additional 83 years. This effect was even more dramatic for the higher solubility DCM (97% of longevity due to matrix diffusion), while the lower solubility PCE showed a more equal contribution from DNAPL dissolution vs. matrix diffusion. Several methods were used to describe the resulting source attenuation curves, including a first-order decay model which showed that half-life of

  5. LEAK: A source term generator for evaluating release rates from leaking vessels

    SciTech Connect

    Clinton, J.H.

    1994-09-01

    An interactive computer code for estimating the rate of release of any one of several materials from a leaking tank or broken pipe leading from a tank is presented. It is generally assumed that the material in the tank is liquid. Materials included in the data base are acetonitrile, ammonia, carbon tetrachloride, chlorine, chlorine trifluoride, fluorine, hydrogen fluoride, nitric acid, nitrogen tetroxide, sodium hydroxide, sulfur hexafluoride, sulfuric acid, and uranium hexafluoride. Materials that exist only as liquid and/or vapor over expected ranges of temperature and pressure can easily be added to the data base file. The Fortran source code for LEAK and the data file are included with this report.

  6. Analytic solutions of the time-dependent quasilinear diffusion equation with source and loss terms

    SciTech Connect

    Hassan, M.H.A. ); Hamza, E.A. )

    1993-08-01

    A simplified one-dimensional quasilinear diffusion equation describing the time evolution of collisionless ions in the presence of ion-cyclotron-resonance heating, sources, and losses is solved analytically for all harmonics of the ion cyclotron frequency. Simple time-dependent distribution functions which are initially Maxwellian and vanish at high energies are obtained and calculated numerically for the first four harmonics of resonance heating. It is found that the strongest ion tail of the resulting anisotropic distribution function is driven by heating at the second harmonic followed by heating at the fundamental frequency.

  7. Long-term studies with the Ariel 5 ASM. II - The strong Cygnus sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. J.

    1979-01-01

    The three bright 3-6 keV X-ray sources in Cygnus are examined for regular temporal variability with a 1300 day record from the Ariel 5 All-Sky Monitor. The only periods consistently observed are 5.6 days for Cyg X-1, 11.23 days for Cyg X-2, and 4.8 hours for Cyg X-3. The 78.4 day period of Kemp, Herman, and Barbour for Cyg X-1, the 9.843 day period of Cowley, Crampton, and Hutchings for Cyg X-2, and the 16.75 day period of Holt et al. for Cyg X-3 are not confirmed.

  8. The MIT/OSO 7 catalog of X-ray sources - Intensities, spectra, and long-term variability

    NASA Technical Reports Server (NTRS)

    Markert, T. H.; Laird, F. N.; Clark, G. W.; Hearn, D. R.; Sprott, G. F.; Li, F. K.; Bradt, H. V.; Lewin, W. H. G.; Schnopper, H. W.; Winkler, P. F.

    1979-01-01

    This paper is a summary of the observations of the cosmic X-ray sky performed by the MIT 1-40-keV X-ray detectors on OSO 7 between October 1971 and May 1973. Specifically, mean intensities or upper limits of all third Uhuru or OSO 7 cataloged sources (185 sources) in the 3-10-keV range are computed. For those sources for which a statistically significant (greater than 20) intensity was found in the 3-10-keV band (138 sources), further intensity determinations were made in the 1-15-keV, 1-6-keV, and 15-40-keV energy bands. Graphs and other simple techniques are provided to aid the user in converting the observed counting rates to convenient units and in determining spectral parameters. Long-term light curves (counting rates in one or more energy bands as a function of time) are plotted for 86 of the brighter sources.

  9. Asymptotically and exactly energy balanced augmented flux-ADER schemes with application to hyperbolic conservation laws with geometric source terms

    NASA Astrophysics Data System (ADS)

    Navas-Montilla, A.; Murillo, J.

    2016-07-01

    In this work, an arbitrary order HLL-type numerical scheme is constructed using the flux-ADER methodology. The proposed scheme is based on an augmented Derivative Riemann solver that was used for the first time in Navas-Montilla and Murillo (2015) [1]. Such solver, hereafter referred to as Flux-Source (FS) solver, was conceived as a high order extension of the augmented Roe solver and led to the generation of a novel numerical scheme called AR-ADER scheme. Here, we provide a general definition of the FS solver independently of the Riemann solver used in it. Moreover, a simplified version of the solver, referred to as Linearized-Flux-Source (LFS) solver, is presented. This novel version of the FS solver allows to compute the solution without requiring reconstruction of derivatives of the fluxes, nevertheless some drawbacks are evidenced. In contrast to other previously defined Derivative Riemann solvers, the proposed FS and LFS solvers take into account the presence of the source term in the resolution of the Derivative Riemann Problem (DRP), which is of particular interest when dealing with geometric source terms. When applied to the shallow water equations, the proposed HLLS-ADER and AR-ADER schemes can be constructed to fulfill the exactly well-balanced property, showing that an arbitrary quadrature of the integral of the source inside the cell does not ensure energy balanced solutions. As a result of this work, energy balanced flux-ADER schemes that provide the exact solution for steady cases and that converge to the exact solution with arbitrary order for transient cases are constructed.

  10. Einstein-like field equations with conserved source and decreasing and Λ term; Their cosmological consequences

    NASA Astrophysics Data System (ADS)

    Massa, Corrado

    1996-03-01

    The consequences of a cosmological ∧ term varying asS -2 in a spatially isotropic universe with scale factorS and conserved matter tensor are investigated. One finds a perpetually expanding universe with positive ∧ and gravitational ‘constant’G that increases with time. The ‘hard’ equation of state 3P>U (U mass-energy density,P scalar pressure) applied to the early universe leads to the expansion lawS∝t (t cosmic time) which solves the horizon problem with no need of inflation. Also the flatness problem is resolved without inflation. The model does not affect the well known predictions on the cosmic light elements abundance which come from standard big bang cosmology. In the present, matter dominated universe one findsdG/dt=2∧H/U (H is the Hubble parameter) which is consistent with observations provided ∧<10-57 cm-2. Asymptotically (S→∞) the ∧ term equalsGU/2, in agreement with other studies.

  11. The Fukushima releases: an inverse modelling approach to assess the source term by using gamma dose rate observations

    NASA Astrophysics Data System (ADS)

    Saunier, Olivier; Mathieu, Anne; Didier, Damien; Tombette, Marilyne; Quélo, Denis; Winiarek, Victor; Bocquet, Marc

    2013-04-01

    The Chernobyl nuclear accident and more recently the Fukushima accident highlighted that the largest source of error on consequences assessment is the source term estimation including the time evolution of the release rate and its distribution between radioisotopes. Inverse modelling methods have proved to be efficient to assess the source term due to accidental situation (Gudiksen, 1989, Krysta and Bocquet, 2007, Stohl et al 2011, Winiarek et al 2012). These methods combine environmental measurements and atmospheric dispersion models. They have been recently applied to the Fukushima accident. Most existing approaches are designed to use air sampling measurements (Winiarek et al, 2012) and some of them use also deposition measurements (Stohl et al, 2012, Winiarek et al, 2013). During the Fukushima accident, such measurements are far less numerous and not as well distributed within Japan than the dose rate measurements. To efficiently document the evolution of the contamination, gamma dose rate measurements were numerous, well distributed within Japan and they offered a high temporal frequency. However, dose rate data are not as easy to use as air sampling measurements and until now they were not used in inverse modelling approach. Indeed, dose rate data results from all the gamma emitters present in the ground and in the atmosphere in the vicinity of the receptor. They do not allow one to determine the isotopic composition or to distinguish the plume contribution from wet deposition. The presented approach proposes a way to use dose rate measurement in inverse modeling approach without the need of a-priori information on emissions. The method proved to be efficient and reliable when applied on the Fukushima accident. The emissions for the 8 main isotopes Xe-133, Cs-134, Cs-136, Cs-137, Ba-137m, I-131, I-132 and Te-132 have been assessed. The Daiichi power plant events (such as ventings, explosions…) known to have caused atmospheric releases are well identified in

  12. The Use of Selected Portions of Technical Documents as Sources of Index Terms and Effect on Input Costs and Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Schumacher, H. H.; And Others

    A correlation between recall (the retrieval of all available relevant documents) and quantity of text which served as a source of index terms on input can reasonably be expected. Specifically, recall should decrease as the quantity of text serving as a source of index terms is restricted. On the other hand, the time for indexing and therefore the…

  13. The Belgian approach and status on the radiological surveillance of radioactive substances in metal scrap and non-radioactive waste and the financing of orphan sources

    SciTech Connect

    Braeckeveldt, Marnix; Preter, Peter De

    2007-07-01

    Numerous facilities in the non-nuclear sector in Belgium (e.g. in the non-radioactive waste processing and management sector and in the metal recycling sector) have been equipped with measuring ports for detecting radioactive substances. These measuring ports prevent radioactive sources or radioactive contamination from ending up in the material fluxes treated by the sectors concerned. They thus play an important part in the protection of the workers and the people living in the neighbourhood of the facilities, as well as in the protection of the population and the environment in general. In 2006, Belgium's federal nuclear control agency (FANC/AFCN) drew up guidelines for the operators of non-nuclear facilities with a measuring port for detecting radioactive substances. These guidelines describe the steps to be followed by the operators when the port's alarm goes off. Following the publication of the European guideline 2003/122/EURATOM of 22 December 2003 on the control of high-activity sealed radioactive sources and orphan sources, a procedure has been drawn up by FANC/AFCN and ONDRAF/NIRAS, the Belgian National Agency for Radioactive Waste and Enriched Fissile Materials, to identify the responsible to cover the costs relating to the further management of detected sealed sources and if not found to declare the sealed source as an orphan source. In this latter case and from mid-2006 the insolvency fund managed by ONDRAF/NIRAS covers the cost of radioactive waste management. At the request of the Belgian government, a financing proposal for the management of unsealed orphan sources as radioactive waste was also established by FANC/AFCN and ONDRAF/NIRAS. This proposal applies the same approach as for sealed sources and thus the financing of unsealed orphan sources will also be covered by the insolvency fund. (authors)

  14. Extraction of Temporal Networks from Term Co-Occurrences in Online Textual Sources

    PubMed Central

    Popović, Marko; Štefančić, Hrvoje; Sluban, Borut; Kralj Novak, Petra; Grčar, Miha; Mozetič, Igor; Puliga, Michelangelo; Zlatić, Vinko

    2014-01-01

    A stream of unstructured news can be a valuable source of hidden relations between different entities, such as financial institutions, countries, or persons. We present an approach to continuously collect online news, recognize relevant entities in them, and extract time-varying networks. The nodes of the network are the entities, and the links are their co-occurrences. We present a method to estimate the significance of co-occurrences, and a benchmark model against which their robustness is evaluated. The approach is applied to a large set of financial news, collected over a period of two years. The entities we consider are 50 countries which issue sovereign bonds, and which are insured by Credit Default Swaps (CDS) in turn. We compare the country co-occurrence networks to the CDS networks constructed from the correlations between the CDS. The results show relatively small, but significant overlap between the networks extracted from the news and those from the CDS correlations. PMID:25470498

  15. Continuous observations of long-term variations in cosmic X-ray sources

    NASA Technical Reports Server (NTRS)

    Wende, C. D.; Krimigis, S. M.; Kohl, J. W.

    1975-01-01

    Results are reported for the Charged Particle Measurements Experiment which was conducted on board IMP-7 to detect X-ray fluxes from the sun, the galactic center, Tau X-1, and Sco X-1 over a nine-month period. Autocorrelation analysis of the data indicates a probable 80-day periodicity in the flux from Sco X-1, a 110-day periodicity in the flux from the galactic center, no periodicities in the flux from Tau X-1, and a strong 27-day periodicity in the solar X-ray flux. A transient event detected within the cluster of sources constituting the galactic center is reported which lasted about two months and had a flux roughly equal to the regular flux from this area. It is noted that this was the only transient event detected in the whole area under continuous observation for the duration of the experiment.

  16. Numerical Dissipation and Wrong Propagation Speed of Discontinuities for Stiff Source Terms

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Kotov, D. V.; Sjogreen, B.

    2011-01-01

    In compressible turbulent combustion/nonequilibrium flows, the constructions of numerical schemes for (a) stable and accurate simulation of turbulence with strong shocks, and (b) obtaining correct propagation speed of discontinuities for stiff reacting terms on coarse grids share one important ingredient - minimization of numerical dissipation while maintaining numerical stability. Here coarse grids means standard mesh density requirement for accurate simulation of typical non-reacting flows. This dual requirement to achieve both numerical stability and accuracy with zero or minimal use of numerical dissipation is most often conflicting for existing schemes that were designed for non-reacting flows. The goal of this paper is to relate numerical dissipations that are inherited in a selected set of high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities for two representative stiff detonation wave problems.

  17. A simplified radionuclide source term for total-system performance assessment; Yucca Mountain Site Characterization Project

    SciTech Connect

    Wilson, M.L.

    1991-11-01

    A parametric model for releases of radionuclides from spent-nuclear-fuel containers in a waste repository is presented. The model is appropriate for use in preliminary total-system performance assessments of the potential repository site at Yucca Mountain, Nevada; for this reason it is simpler than the models used for detailed studies of waste-package performance. Terms are included for releases from the spent fuel pellets, from the pellet/cladding gap and the grain boundaries within the fuel pellets, from the cladding of the fuel rods, and from the radioactive fuel-assembly parts. Multiple barriers are considered, including the waste container, the fuel-rod cladding, the thermal ``dry-out``, and the waste form itself. The basic formulas for release from a single fuel rod or container are extended to formulas for expected releases for the whole repository by using analytic expressions for probability distributions of some important parameters. 39 refs., 4 figs., 4 tabs.

  18. Depleted uranium residual radiological risk assessment for Kosovo sites.

    PubMed

    Durante, Marco; Pugliese, Mariagabriella

    2003-01-01

    During the recent conflict in Yugoslavia, depleted uranium rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of areas in Kosovo with depleted uranium penetrators and dust. Although chemical toxicity is the most significant health risk related to uranium, radiation exposure has been allegedly related to cancers among veterans of the Balkan conflict. Uranium munitions are considered to be a source of radiological contamination of the environment. Based on measurements and estimates from the recent Balkan Task Force UNEP mission in Kosovo, we have estimated effective doses to resident populations using a well-established food-web mathematical model (RESRAD code). The UNEP mission did not find any evidence of widespread contamination in Kosovo. Rather than the actual measurements, we elected to use a desk assessment scenario (Reference Case) proposed by the UNEP group as the source term for computer simulations. Specific applications to two Kosovo sites (Planeja village and Vranovac hill) are described. Results of the simulations suggest that radiation doses from water-independent pathways are negligible (annual doses below 30 microSv). A small radiological risk is expected from contamination of the groundwater in conditions of effective leaching and low distribution coefficient of uranium metal. Under the assumptions of the Reference Case, significant radiological doses (>1 mSv/year) might be achieved after many years from the conflict through water-dependent pathways. Even in this worst-case scenario, DU radiological risk would be far overshadowed by its chemical toxicity. PMID:12500808

  19. Sources, sinks and long-term cycling of iodine in the hyperarid Atacama continental margin

    NASA Astrophysics Data System (ADS)

    Álvarez, Fernanda; Reich, Martin; Pérez-Fodich, Alida; Snyder, Glen; Muramatsu, Yasuyuki; Vargas, Gabriel; Fehn, Udo

    2015-07-01

    The Atacama region in northern Chile hosts the driest desert on Earth and is the world's premier iodine production province. The origin of iodine enrichment in Atacama is controversial and fundamentally different processes have been invoked over the years that involve marine, eolian and more recently deep sedimentary fluid and groundwater sources. As a result of the very limited geochemical iodine data in Atacama and the western South American margin, the origin of iodine enrichment in this region still remains elusive. In this study, we present a comprehensive survey of iodine concentrations and isotopic ratios (129I/I) of different reservoirs in the Atacama Desert of northern Chile, including nitrate soils, supergene copper deposits, marine sedimentary rocks, geothermal fluids, groundwater and meteoric water. Nitrate soils along the eastern slope of the Coastal Cordillera are found to have mean iodine concentrations of at least three orders of magnitude higher than the mean crustal abundances of ∼0.12 ppm, with a mean concentration of ∼700 ppm. Soils above giant copper deposits in the Central Depression are also highly enriched in iodine (100's of ppm range), and Cu-iodide and iodate minerals occur in the supergene enrichment zones of some of these deposits. Further east in the Precordillera, Jurassic sedimentary shales and limestones show above-background iodine concentrations, the latter averaging ∼50 ppm in the southern portion of the study area. The highest iodine concentrations in fluids were measured in groundwater below nitrate soils in the Coastal Range (∼3.5-10 ppm) and in geothermal waters (1-3 ppm) along the volcanic arc. Although highly variable, the iodine isotopic ratios (129I/I) of Jurassic marine sedimentary rocks (∼300-600 × 10-15), nitrate soils (∼150-1500 × 10-15) and waters (∼215 × 10-15) are consistently low (<1500 × 10-15), indicating that recent anthropogenic additions are almost negligible in most surficial and deeper

  20. Review of Technical Issues Related to Predicting Isotopic Compositions and Source Terms for High-Burnup LWR Fuel

    SciTech Connect

    Gauld, I. C.; Parks, C. V.

    2000-12-11

    This report has been prepared to review the technical issues important to the prediction of isotopic compositions and source terms for high-burnup, light-water-reactor (LWR) fuel as utilized in the licensing of spent fuel transport and storage systems. The current trend towards higher initial 235U enrichments, more complex assembly designs, and more efficient fuel management schemes has resulted in higher spent fuel burnups than seen in the past. This trend has led to a situation where high-burnup assemblies from operating LWRs now extend beyond the area where available experimental data can be used to validate the computational methods employed to calculate spent fuel inventories and source terms. This report provides a brief review of currently available validation data, including isotopic assays, decay heat measurements, and shielded dose-rate measurements. Potential new sources of experimental data available in the near term are identified. A review of the background issues important to isotopic predictions and some of the perceived technical challenges that high-burnup fuel presents to the current computational methods are discussed. Based on the review, the phenomena that need to be investigated further and the technical issues that require resolution are presented. The methods and data development that may be required to address the possible shortcomings of physics and depletion methods in the high-burnup and high-enrichment regime are also discussed. Finally, a sensitivity analysis methodology is presented. This methodology is currently being investigated at the Oak Ridge National Laboratory as a computational tool to better understand the changing relative significance of the underlying nuclear data in the different enrichment and burnup regimes and to identify the processes that are dominant in the high-burnup regime. The potential application of the sensitivity analysis methodology to help establish a range of applicability for experimental

  1. Imbalance of energy and momentum source terms of the sea wave transfer equation for fully developed seas

    NASA Astrophysics Data System (ADS)

    Caudal, G. V.

    2012-12-01

    In the concept of full development, the sea wave spectrum is regarded as a nearly stationary solution of the wave transfer equation, where source and sink terms should be in balance with respect to both energy and momentum. Using a two-dimensional empirical sea wave spectral model at full development, this paper performs an assessment of the compatibility of the energy and momentum budgets of sea waves over the whole spectral range. Among the various combinations of model functions for wave breaking and wind source terms tested, not one is found to fulfill simultaneously the energy and momentum balance of the transfer equation. Based on experimental and theoretical grounds, wave breaking is known to contribute to frequency downshift of a narrow-banded wave spectrum when the modulational instability is combined with wave breaking. On those grounds, it is assumed that, in addition to dissipation, wave breaking produces a spectral energy flux directed toward low wavenumbers. I show that it is then possible to remove the energy and momentum budget inconsistency, and correspondingly the required strength of this spectral flux is estimated. Introducing such a downward spectral flux permits fulfilling both energy and momentum balance conditions. Meanwhile, the consistency between the transfer equation and empirical spectra, estimated by means of a cost function K, is either improved or slightly reduced, depending upon the wave breaking and wind source terms chosen. Other tests are performed in which it is further assumed that wave breaking would also be associated with azimuthal diffusion of the spectral energy. This would correspondingly reduce the required downward spectral flux by a factor of up to 5, although it would not be able to remove it entirely.

  2. Long-term monitoring of airborne nickel (Ni) pollution in association with some potential source processes in the urban environment.

    PubMed

    Kim, Ki-Hyun; Shon, Zang-Ho; Mauulida, Puteri T; Song, Sang-Keun

    2014-09-01

    The environmental behavior and pollution status of nickel (Ni) were investigated in seven major cities in Korea over a 13-year time span (1998-2010). The mean concentrations of Ni measured during the whole study period fell within the range of 3.71 (Gwangju: GJ) to 12.6ngm(-3) (Incheon: IC). Although Ni values showed a good comparability in a relatively large spatial scale, its values in most cities (6 out of 7) were subject to moderate reductions over the study period. To assess the effect of major sources on the long-term distribution of Ni, the relationship between their concentrations and the potent source processes like non-road transportation sources (e.g., ship and aircraft emissions) were examined from some cities with port and airport facilities. The potential impact of long-range transport of Asian dust particles in controlling Ni levels was also evaluated. The overall results suggest that the Ni levels were subject to gradual reductions over the study period irrespective of changes in such localized non-road source activities. The pollution of Ni at all the study sites was maintained well below the international threshold (Directive 2004/107/EC) value of 20ngm(-3). PMID:24997934

  3. Machine Learning and Radiology

    PubMed Central

    Wang, Shijun; Summers, Ronald M.

    2012-01-01

    In this paper, we give a short introduction to machine learning and survey its applications in radiology. We focused on six categories of applications in radiology: medical image segmentation, registration, computer aided detection and diagnosis, brain function or activity analysis and neurological disease diagnosis from fMR images, content-based image retrieval systems for CT or MRI images, and text analysis of radiology reports using natural language processing (NLP) and natural language understanding (NLU). This survey shows that machine learning plays a key role in many radiology applications. Machine learning identifies complex patterns automatically and helps radiologists make intelligent decisions on radiology data such as conventional radiographs, CT, MRI, and PET images and radiology reports. In many applications, the performance of machine learning-based automatic detection and diagnosis systems has shown to be comparable to that of a well-trained and experienced radiologist. Technology development in machine learning and radiology will benefit from each other in the long run. Key contributions and common characteristics of machine learning techniques in radiology are discussed. We also discuss the problem of translating machine learning applications to the radiology clinical setting, including advantages and potential barriers. PMID:22465077

  4. Radiological evaluation of dysphagia

    SciTech Connect

    Ott, D.J.; Gelfand, D.W.; Wu, W.C.; Chen, Y.M.

    1986-11-21

    Dysphagia is a common complaint in patients presenting for radiological or endoscopic examination of the esophagus and is usually due to functional or structural abnormalities of the esophageal body or esophagogastric region. The authors review the radiological evaluation of the esophagus and esophagogastric region in patients with esophageal dysphagia and discuss the roentgenographic techniques used, radiological efficacy for common structural disorders, and evaluation of esophageal motor function. Comparison is made with endoscopy in assessing dysphagia, with the conclusion that the radiological examination be used initially in patients with this complaint.

  5. Measurement and apportionment of radon source terms for modeling indoor environments

    SciTech Connect

    Harley, N.H.

    1992-01-01

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor [sup 222]Rn and in [sup 222]Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house [sup 222]Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater [sup 222]Rn concentration than the measured outdoor [sup 222]Rn. Apartment dwellers generally represent a low risk group regarding [sup 222]Rn exposure. The following sections describe the main projects in some detail.

  6. Long-term exposure of pressed plutonium oxide heat sources to aquatic environments

    SciTech Connect

    Heaton, R.C.; Patterson, J.H.; Kosiewicz, S.T.; Matlack, G.M.; Steinkruger, F.J.; Nelson, G.B.; Vanderborgh, N.E.; Coffelt, K.P.; Herrera, B.

    1984-11-01

    Plutonium-238 oxide fuel pellets were exposed to water for 2.5 to 6.4 yr, and the concentration of plutonium in the water was monitored. Water composition and temperature were found to be important factors in determining the rate of plutonium release into the water. Typical release rates ranged from 10 to 40 ng/m/sup 2//s in cold fresh water and from 0.3 to 11 ng/m/sup 2//s in cold sea water. Release rates in sea water varied over time and sometimes were erratic. The plutonium release per unit area did not depend on the size of the PuO/sub 2/ source. The released plutonium was in an extremely fine form, able to pass through 10,000 molecular weight cutoff filters. Apparent differences in the fuel pellet surfaces after exposure suggest that plutonium release is controlled by physical and chemical processes occurring at the solid-liquid interface. Release mechanisms and their implications are discussed.

  7. Two-dimensional extended fluid model for a dc glow discharge with nonlocal ionization source term

    NASA Astrophysics Data System (ADS)

    Rafatov, Ismail; Bogdanov, Eugeny; Kudryavtsev, Anatoliy

    2013-09-01

    Numerical techniques applied to the gas discharge plasma modelling are generally grouped into fluid and kinetic (particle) methods, and their combinations which lead to the hybrid models. Hybrid models usually employ Monte Carlo method to simulate fast electron dynamics, while slow plasma species are described as fluids. However, since fast electrons contribution to these models is limited to deriving the ionization rate distribution, their effect can be expressed by the analytical approximation of the ionization source function, and then integrating it into the fluid model. In the context of this approach, we incorporated effect of fast electrons into the ``extended fluid model'' of glow discharge, using two spatial dimensions. Slow electrons, ions and excited neutral species are described by the fluid plasma equations. Slow electron transport (diffusion and mobility) coefficients as well as electron induced reaction rates are determined from the solutions of the electron Boltzmann equation. The self-consistent electric field is calculated using the Poisson equation. We carried out test calculations for the discharge in argon gas. Comparison with the experimental data as well as with the hybrid model results exhibits good applicability of the proposed model. The work was supported by the joint research grant from the Scientific and Technical Research Council of Turkey (TUBITAK) 212T164 and Russian Foundation for Basic Research (RFBR).

  8. Mercury in soil near a long-term air emission source in southeastern Idaho

    USGS Publications Warehouse

    Abbott, M.L.; Susong, D.D.; Olson, M.; Krabbenhoft, D.P.

    2003-01-01

    At the Idaho National Engineering and Environmental Laboratory in southeastern Idaho, a 500??C fluidized bed calciner was intermittently operated for 37 years, with measured Hg emission rates of 9-11 g/h. Surface soil was sampled at 57 locations around the facility to determine the spatial distribution of Hg fallout and surface Hg variability, and to predict the total residual Hg mass in the soil from historical emissions. Measured soil concentrations were slightly higher (p<0.05) within 5 km of the source but were overall very low (15-20 ng/g) compared to background Hg levels published for similar soils in the USA (50-70 ng/g). Concentrations decreased 4%/cm with depth and were found to be twice as high under shrubs and in depressions. Mass balance calculations accounted for only 2.5-20% of the estimated total Hg emitted over the 37-year calciner operating history. These results suggest that much of the Hg deposited from calciner operations may have been reduced in the soil and re-emitted as Hg(0) to the global atmospheric pool.

  9. Source-Term and building-Wake Consequence Modeling for the Godiva IV Reactor at Los Alamos National Laboratory

    SciTech Connect

    Letellier, B.C.; McClure, P.; Restrepo, L.

    1999-06-13

    The objectives of this work were to evaluate the consequences of a postulated accident to onsite security personnel stationed near the facility during operations of the Godiva IV critical assembly and to identify controls needed to protect these personnel in case of an extreme criticality excursion equivalent to the design-basis accident (DBA). This paper presents the methodology and results of the source-term calculations, building ventilation rates, air concentrations, and consequence calculations that were performed using a multidisciplinary approach with several phenomenology models. Identification of controls needed to mitigate the consequences to near-field receptors is discussed.

  10. Underground Test Area Subproject Phase I Data Analysis Task. Volume V - Transport Parameter and Source Term Data Documentation Package

    SciTech Connect

    1996-12-01

    Volume V of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the transport parameter and source term data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

  11. Spatial distribution of HTO activity in unsaturated soil depth in the vicinity of long-term release source

    SciTech Connect

    Golubev, A.; Golubeva, V.; Mavrin, S.

    2015-03-15

    Previous studies reported about a correlation between HTO activity distribution in unsaturated soil layer and atmospheric long-term releases of HTO in the vicinity of Savannah River Site. The Tritium Working Group of BIOMASS Programme has performed a model-model intercomparison study of HTO transport from atmosphere to unsaturated soil and has evaluated HTO activity distribution in the unsaturated soil layer in the vicinity of permanent atmospheric sources. The Tritium Working Group has also reported about such a correlation, however the conclusion was that experimental data sets are needed to confirm this conclusion and also to validate appropriate computer models. (authors)

  12. Integrating Data Sources to Optimize Long-Term Monitoring and Management: A Machine Learning Approach

    NASA Astrophysics Data System (ADS)

    Michael, W. J.; Tcheng, D. K.; Minsker, B. S.; Valocchi, A. J.; Quinn, J. J.; Williams, G. P.

    2002-05-01

    As the groundwater remediation field matures and the installation of remediation systems are completed, it is becoming clear that long-term monitoring and management of these systems will comprise a significant portion of future expenditures. The University of Illinois and Argonne National Laboratory have collaborated to demonstrate how integrating all available site data can improve decision making and provide cost savings. A learning machine is used to integrate historic and current data from the 317/319 Area phytoremediation site at Argonne National Lab-East (ANL-E) to provide a better understanding of site processes and direct future data collection. Site data used in this study include: hourly head measurements from a subset of seven monitoring wells and quarterly from the remaining wells. The learning machine uses these data and daily weather data (to account for the impact of recharge on the groundwater regime) to forecast groundwater head levels. The performance of the model built by the learning machine is assessed by comparing predictions from previous monitoring periods to the most recently available data. By comparing predictive performance using different combinations of datasets, the most relevant data are identified to guide future sampling efforts. Combining non-traditional data sets and optimizing the value of current data as demonstrated in this paper will improve predictions so that the most useful data can be collected efficiently and cost-effectively.

  13. Estimating Uncertainty in Long Term Total Ozone Records from Multiple Sources

    NASA Technical Reports Server (NTRS)

    Frith, Stacey M.; Stolarski, Richard S.; Kramarova, Natalya; McPeters, Richard D.

    2014-01-01

    Total ozone measurements derived from the TOMS and SBUV backscattered solar UV instrument series cover the period from late 1978 to the present. As the SBUV series of instruments comes to an end, we look to the 10 years of data from the AURA Ozone Monitoring Instrument (OMI) and two years of data from the Ozone Mapping Profiler Suite (OMPS) on board the Suomi National Polar-orbiting Partnership satellite to continue the record. When combining these records to construct a single long-term data set for analysis we must estimate the uncertainty in the record resulting from potential biases and drifts in the individual measurement records. In this study we present a Monte Carlo analysis used to estimate uncertainties in the Merged Ozone Dataset (MOD), constructed from the Version 8.6 SBUV2 series of instruments. We extend this analysis to incorporate OMI and OMPS total ozone data into the record and investigate the impact of multiple overlapping measurements on the estimated error. We also present an updated column ozone trend analysis and compare the size of statistical error (error from variability not explained by our linear regression model) to that from instrument uncertainty.

  14. DRINK: a biogeochemical source term model for low level radioactive waste disposal sites.

    PubMed

    Humphreys, P; McGarry, R; Hoffmann, A; Binks, P

    1997-07-01

    Interactions between element chemistry and the ambient geochemistry play a significant role in the control of radionuclide migration in the geosphere. These same interactions influence radionuclide release from near surface, low level radioactive waste, disposal sites once physical containment has degraded. In situations where LLW contains significant amounts of metal and organic materials such as cellulose, microbial degradation in conjunction with corrosion can significantly perturb the ambient geochemistry. These processes typically produce a transition from oxidising to reducing conditions and can influence radionuclide migration through changes in both the dominant radionuclide species and mineral phases. The DRINK (DRIgg Near field Kinetic) code is a biogeochemical transport code designed to simulate the long term evolution of the UK low level radioactive waste disposal site at Drigg. Drigg is the UK's principal solid low level radioactive waste disposal site and has been receiving waste since 1959. The interaction between microbial activity, the ambient geochemistry and radionuclide chemistry is central to the DRINK approach with the development of the ambient pH, redox potential and bulk geochemistry being directly influenced by microbial activity. This paper describes the microbial aspects of the code, site data underpinning the microbial model, the microbiology/chemistry interface and provides an example of the code in action. PMID:9340003

  15. Toronto area ozone: Long-term measurements and modeled sources of poor air quality events

    NASA Astrophysics Data System (ADS)

    Whaley, C. H.; Strong, K.; Jones, D. B. A.; Walker, T. W.; Jiang, Z.; Henze, D. K.; Cooke, M. A.; McLinden, C. A.; Mittermeier, R. L.; Pommier, M.; Fogal, P. F.

    2015-11-01

    The University of Toronto Atmospheric Observatory and Environment Canada's Centre for Atmospheric Research Experiments each has over a decade of ground-based Fourier transform infrared (FTIR) spectroscopy measurements in southern Ontario. We present the Toronto area FTIR time series from 2002 to 2013 of two tropospheric trace gases—ozone and carbon monoxide—along with surface in situ measurements taken by government monitoring programs. We interpret their variability with the GEOS-Chem chemical transport model and determine the atmospheric conditions that cause pollution events in the time series. Our analysis includes a regionally tagged O3 model of the 2004-2007 time period, which quantifies the geographical contributions to Toronto area O3. The important emission types for 15 pollution events are then determined with a high-resolution adjoint model. Toronto O3, during pollution events, is most sensitive to southern Ontario and U.S. fossil fuel NOx emissions and natural isoprene emissions. The sources of Toronto pollution events are found to be highly variable, and this is demonstrated in four case studies representing local, short-, middle-, and long-range transport scenarios. This suggests that continental-scale emission reductions could improve air quality in the Toronto region. We also find that abnormally high temperatures and high-pressure systems are common to all pollution events studied, suggesting that climate change may impact Toronto O3. Finally, we quantitatively compare the sensitivity of the surface and column measurements to anthropogenic NOx emissions and show that they are remarkably similar. This work thus demonstrates the usefulness of FTIR measurements in an urban area to assess air quality.

  16. Long-term Science Data Curation Using a Digital Object Model and Open-Source Frameworks

    NASA Astrophysics Data System (ADS)

    Pan, J.; Lenhardt, W.; Wilson, B. E.; Palanisamy, G.; Cook, R. B.

    2010-12-01

    Scientific digital content, including Earth Science observations and model output, has become more heterogeneous in format and more distributed across the Internet. In addition, data and metadata are becoming necessarily linked internally and externally on the Web. As a result, such content has become more difficult for providers to manage and preserve and for users to locate, understand, and consume. Specifically, it is increasingly harder to deliver relevant metadata and data processing lineage information along with the actual content consistently. Readme files, data quality information, production provenance, and other descriptive metadata are often separated in the storage level as well as in the data search and retrieval interfaces available to a user. Critical archival metadata, such as auditing trails and integrity checks, are often even more difficult for users to access, if they exist at all. We investigate the use of several open-source software frameworks to address these challenges. We use Fedora Commons Framework and its digital object abstraction as the repository, Drupal CMS as the user-interface, and the Islandora module as the connector from Drupal to Fedora Repository. With the digital object model, metadata of data description and data provenance can be associated with data content in a formal manner, so are external references and other arbitrary auxiliary information. Changes are formally audited on an object, and digital contents are versioned and have checksums automatically computed. Further, relationships among objects are formally expressed with RDF triples. Data replication, recovery, metadata export are supported with standard protocols, such as OAI-PMH. We provide a tentative comparative analysis of the chosen software stack with the Open Archival Information System (OAIS) reference model, along with our initial results with the existing terrestrial ecology data collections at NASA’s ORNL Distributed Active Archive Center for

  17. Application of multisorbent traps to characterization and quantification of workplace exposure source terms

    SciTech Connect

    Dindal, A.B.; Ma, Cheng-Yu; Jenkins, R.A.; Higgins, C.E.; Skeen, J.T.; Bayne, C.K.

    1995-08-01

    Multisorbent traps have been used for several years to characterize complex atmospheres. Only more recently have multisorbent traps been used for quantitative analysis. The traps provide an effective method for retaining a wide range of airborne Organic contaminants, since these carbonaceous sorbents are relatively hydrophobic, have large surface areas, do not have active functional groups, and have fewer chemical artifacts than other sorbents. Multisorbent traps, which are 76 mm in length and have a 6 mm outside diameter, contain sequentially loaded beds of Carbotrap C, Carbotrap, and Carbosieve SIII, similar to a commercially available trap. The injection port of a gas chromatograph is configured for thermal desorption analysis of the traps via an in-house modification. Currently, multisorbent traps are being used to sample the headspace of underground storage tanks at the Department of Energy`s Hanford site, in Richland, Washington. The analyses are performed by flame ionization or mass spectrometric detection. Target organic analytes include C{sub 6} to C{sub 13} alkanes, nitriles, alkyl ketones, dibutyl butyl phosphonate and tributyl phosphate. Pre-analytical holding times or practical reporting times for many target analytes are at least 84 days under either refrigerated or ambient conditions. Traps are fabricated, conditioned, and spiked with three surrogate standards in the vapor phase prior to shipment to the site. Recovery of the surrogates from the multisorbent traps serve as a statistical process control. Source concentrations of Hanford underground storage tank headspaces range from 0.96 mg/m{sup 3} to 1200 mg/m{sup 3}.

  18. Short and long term energy source technologies for electrically-heated catalysts

    SciTech Connect

    Bass, E.A.; Johnston, R.; Hunt, B.; Rodriguez, G.; Gottberg, I.; Ishizuka, A.; Hall, W.

    1996-12-31

    A consortium of six companies formed by Southwest Research Institute conducted an investigation into alternative electric power supplies for electrically heated catalysts (EHCs). Previous studies showed that, due to their high power and energy requirements upon engine start, battery-powered EHCs would cause premature failure of common lead-acid batteries. This project identified and characterized several alternative electric energy sources. Production starting, lighting, and ignition (SLI) batteries were evaluated along with lead-acid electric vehicle batteries, nickel-cadmium aircraft batteries, prototype ultracapacitors, and a modified alternator. Battery Council International and US Advanced Battery Consortium test methods were employed where applicable. Evaluations included ambient and low-temperature ({minus}18 C) constant-current discharge characterization, low-temperature peak-power determination, self-discharge, and passenger car Federal Test Procedure (FTP) emissions and fuel economy. As demonstrated by discharge-energy and peak-power tests, some EV batteries may have potential for the EHC/SLI application. Other appeared to be poorly suited due to low-temperature problems. The best low-temperature performance was observed with ultracapacitors. These units were also the least to be affected by the power versus energy trade-off. The problems with these prototype storage units were high cost and self-discharge rate. Alternator power for EHCs as an alternative to energy storage devices was successfully demonstrated on a vehicle. Power produced was a linear function of engine speed and EHC load. High-voltage switching devices will be necessary for successful use of alternator power on EHCs. A fuel economy penalty was expected, but not observed during the FTP vehicle demonstration.

  19. Short-term controls on the age of microbial carbon sources in boreal forest soils

    NASA Astrophysics Data System (ADS)

    Czimczik, Claudia I.; Trumbore, Susan E.

    2007-09-01

    One predicted positive feedback of increasing temperatures in the boreal region is carbon (C) loss through enhanced microbial decomposition of soil organic matter (SOM). The degree to which temperature sensitivity for decomposition varies across a range of C-substrates remains uncertain. Using incubations, we tested whether microorganisms shift to more recalcitrant substrates (with longer turnover times) at higher temperatures at low or increased soil moisture. We measured the radiocarbon (Δ14C) and stable isotope (δ13C) signature of CO2 respired from organic soils from six black spruce forests (0 to 150 years since fire). We identified major C substrates contributing to decomposition by comparing Δ14C of CO2 to Δ14C of roots, mosses, needles, and wood separated from bulk SOM. The Δ14C signatures of these components allow an estimation of their turnover times, further constraining their relative contribution to respiration. Fastest turnover rates were observed for herbaceous litter and needles (annual to decadal) for mosses, with intermediate turnover times for roots. Dominant microbial C sources in 5 to 40 year old stands were fire remnants and litter of early succession species, while substrates with longer turnover times accounted for a larger proportion of CO2 in mature stands. At both low and increased moisture levels, the increase in CO2 efflux at higher temperatures was accompanied by a decline in δ13CO2, but no shift in Δ14CO2. This suggests that temperature sensitivity is not greater for recalcitrant C and that changes in δ13C likely reflect temperature dependence of microbial fractionation processes rather than a substrate shift.

  20. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, April 1-June 30, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1981-09-01

    The containers for /sup 238/PuO/sub 2/ heat sources in radioisotope thermoelectric generators are designed with large safety factors to ensure they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. This report includes data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO/sub 2/ dissolution rates, soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments.

  1. Leadership and management in quality radiology

    PubMed Central

    2007-01-01

    The practice of medical imaging and interventional radiology are undergoing rapid change in recent years due to technological advances, workload escalation, workforce shortage, globalisation, corporatisation, commercialisation and commoditisation of healthcare. These professional and economical changes are challenging the established norm but may bring new opportunities. There is an increasing awareness of and interest in the quality of care and patient safety in medical imaging and interventional radiology. Among the professional organisations, a range of quality systems are available to address individual, facility and system needs. To manage the limited resources successfully, radiologists and professional organisations must be leaders and champion for the cause of quality care and patient safety. Close collaboration with other stakeholders towards the development and management of proactive, long-term, system-based strategies and infrastructures will underpin a sustainable future in quality radiology. The International Radiology Quality Network can play a useful facilitating role in this worthwhile but challenging endeavour. PMID:21614284

  2. Evaluation of severe accident risks: Methodology for the containment, source term, consequence, and risk integration analyses; Volume 1, Revision 1

    SciTech Connect

    Gorham, E.D.; Breeding, R.J.; Brown, T.D.; Harper, F.T.; Helton, J.C.; Murfin, W.B.; Hora, S.C.

    1993-12-01

    NUREG-1150 examines the risk to the public from five nuclear power plants. The NUREG-1150 plant studies are Level III probabilistic risk assessments (PRAs) and, as such, they consist of four analysis components: accident frequency analysis, accident progression analysis, source term analysis, and consequence analysis. This volume summarizes the methods utilized in performing the last three components and the assembly of these analyses into an overall risk assessment. The NUREG-1150 analysis approach is based on the following ideas: (1) general and relatively fast-running models for the individual analysis components, (2) well-defined interfaces between the individual analysis components, (3) use of Monte Carlo techniques together with an efficient sampling procedure to propagate uncertainties, (4) use of expert panels to develop distributions for important phenomenological issues, and (5) automation of the overall analysis. Many features of the new analysis procedures were adopted to facilitate a comprehensive treatment of uncertainty in the complete risk analysis. Uncertainties in the accident frequency, accident progression and source term analyses were included in the overall uncertainty assessment. The uncertainties in the consequence analysis were not included in this assessment. A large effort was devoted to the development of procedures for obtaining expert opinion and the execution of these procedures to quantify parameters and phenomena for which there is large uncertainty and divergent opinions in the reactor safety community.

  3. The Need for Confirmatory Experiments on the Radioactive Source Term from Potential Sabotage of Spent Nuclear Fuel Casks

    SciTech Connect

    PHILBIN, JEFFREY S.; HOOVER, MARK D.; NEWTON, GEORGE J.

    2002-04-01

    A technical review is presented of experiment activities and state of knowledge on air-borne, radiation source terms resulting from explosive sabotage attacks on spent reactor fuel subassemblies in shielded casks. Current assumptions about the behavior of irradiated fuel are largely based on a limited number of experimental results involving unirradiated, depleted uranium dioxide ''surrogate'' fuel. The behavior of irradiated nuclear fuel subjected to explosive conditions could be different from the behavior of the surrogate fuel, depending on the assumptions made by the evaluator. Available data indicate that these potential differences could result in errors, and possible orders-of-magnitude overestimates of aerosol dispersion and potential health effects from sabotage attacks. Furthermore, it is suggested that the current assumptions used in arriving at existing regulations for the transportation and storage of spent fuel in the U.S. are overly conservative. This, in turn, has led to potentially higher-than-needed operating expenses for those activities. A confirmatory experimental program is needed to develop a realistic correlation between source terms of irradiated fuel and unirradiated fuel. The motivations for performing the confirmatory experimental program are also presented.

  4. Application of the revised DBA source term to a non-charcoal-filtered control room ventilation system

    SciTech Connect

    Radvansky, M.S.; Metcalf, J.E.

    1997-12-01

    An outstanding licensing issue at GPU Nuclear`s Oyster Creek plant had been the question of thyroid dose to a control room operator following the Title 10, Code of Federal Regulations, Part 100 (10 CFR 100) design basis accident (DBA). Oyster Creek is a 620-MW boiling water reactor (BWR), located in New Jersey, that began commercial operation in December 1969. The calculational problem was complicated by the fact that the 28-yr-old unit was one of the few plants that did not incorporate charcoal filtration into the control room ventilation system. The main contributor to the thyroid dose in a control room habitability calculation for a BWR is main steam isolation valve (MSIV) leakage. The technical specification limit for MSIV leakage at Oyster Creek is 15.9 SCFH (maximum) for each isolation valve. The work ongoing in the development of NUREG-1465, the revised DBA source term document, provided a potential method to calculate a more realistic dose compared with the current TID-14844 source term and Regulatory Guide 1.3 input data and accident propagation assumptions. Preliminary calculations using TID-14844 suggested that expensive modifications be made to the plant. Such modifications could have economically challenged the plant`s viability.

  5. Short-term microbial release during rain events from on-site sewers and cattle in a surface water source.

    PubMed

    Aström, Johan; Pettersson, Thomas J R; Reischer, Georg H; Hermansson, Malte

    2013-09-01

    The protection of drinking water from pathogens such as Cryptosporidium and Giardia requires an understanding of the short-term microbial release from faecal contamination sources in the catchment. Flow-weighted samples were collected during two rainfall events in a stream draining an area with on-site sewers and during two rainfall events in surface runoff from a bovine cattle pasture. Samples were analysed for human (BacH) and ruminant (BacR) Bacteroidales genetic markers through quantitative polymerase chain reaction (qPCR) and for sorbitol-fermenting bifidobacteria through culturing as a complement to traditional faecal indicator bacteria, somatic coliphages and the parasitic protozoa Cryptosporidium spp. and Giardia spp. analysed by standard methods. Significant positive correlations were observed between BacH, Escherichia coli, intestinal enterococci, sulphite-reducing Clostridia, turbidity, conductivity and UV254 in the stream contaminated by on-site sewers. For the cattle pasture, no correlation was found between any of the genetic markers and the other parameters. Although parasitic protozoa were not detected, the analysis for genetic markers provided baseline data on the short-term faecal contamination due to these potential sources of parasites. Background levels of BacH and BacR makers in soil emphasise the need to including soil reference samples in qPCR-based analyses for Bacteroidales genetic markers. PMID:23981872

  6. Accident source terms for pressurized water reactors with high-burnup cores calculated using MELCOR 1.8.5.

    SciTech Connect

    Gauntt, Randall O.; Powers, Dana Auburn; Ashbaugh, Scott G.; Leonard, Mark Thomas; Longmire, Pamela

    2010-04-01

    In this study, risk-significant pressurized-water reactor severe accident sequences are examined using MELCOR 1.8.5 to explore the range of fission product releases to the reactor containment building. Advances in the understanding of fission product release and transport behavior and severe accident progression are used to render best estimate analyses of selected accident sequences. Particular emphasis is placed on estimating the effects of high fuel burnup in contrast with low burnup on fission product releases to the containment. Supporting this emphasis, recent data available on fission product release from high-burnup (HBU) fuel from the French VERCOR project are used in this study. The results of these analyses are treated as samples from a population of accident sequences in order to employ approximate order statistics characterization of the results. These trends and tendencies are then compared to the NUREG-1465 alternative source term prescription used today for regulatory applications. In general, greater differences are observed between the state-of-the-art calculations for either HBU or low-burnup (LBU) fuel and the NUREG-1465 containment release fractions than exist between HBU and LBU release fractions. Current analyses suggest that retention of fission products within the vessel and the reactor coolant system (RCS) are greater than contemplated in the NUREG-1465 prescription, and that, overall, release fractions to the containment are therefore lower across the board in the present analyses than suggested in NUREG-1465. The decreased volatility of Cs2MoO4 compared to CsI or CsOH increases the predicted RCS retention of cesium, and as a result, cesium and iodine do not follow identical behaviors with respect to distribution among vessel, RCS, and containment. With respect to the regulatory alternative source term, greater differences are observed between the NUREG-1465 prescription and both HBU and LBU predictions than exist between HBU and LBU

  7. Radiological Defense. Textbook.

    ERIC Educational Resources Information Center

    Defense Civil Preparedness Agency (DOD), Washington, DC.

    This textbook has been prepared under the direction of the Defense Civil Preparedness Agency (DCPA) Staff College for use as a student reference manual in radiological defense (RADEF) courses. It provides much of the basic technical information necessary for a proper understanding of radiological defense and summarizes RADEF planning and expected…

  8. RadiologyInfo: Glossary of Terms

    MedlinePlus

    ... and pelvic organs and the legs. abdominal aortic aneurysm (AAA) Sometimes called triple A. A ballooning out ... or weakness in the vessel wall (called an aneurysm ) that occurs in the portion of the aorta ...

  9. Environmental and radiological safety studies. Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 30, 1980

    SciTech Connect

    Waterbury, G.R.

    1981-01-01

    The containers for /sup 238/PuO/sub 2/ heat sources in radioisotope thermoelectric generators are designed with large safety factors to ensure that they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. The data obtained in several ongoing experiments are presented; these data tables will be updated quarterly. Discussions of experimental details are minimized and largely repetitive in succeeding reports. Compilations of usable data generated in each experiment are emphasized. These compilations include data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO/sub 2/ dissolution rates, soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments.

  10. Studies of HT and HTO Behavior in the Vicinity of Long-Term Emission Source: Model - Experiment Intercomparison

    SciTech Connect

    Golubev, A. V.; Aleinikov, A. Y.; Golubeva, V. N.; Khabibulin, M. M.; Glagolev, M. V.; Misatyuk, S. E.; Mavrin, S. V.; Belot, Y. A.; Raskob, W.; Tate, P. J.

    2003-02-24

    There are presented in the research results of HT and HTO deposition and the model of HT (HTO) atmosphere concentration in the vicinity of a long-term HT and HTO emission source. Scavenging of HTO by precipitations was studied in 6 field experiments. The site of the scavenging experiments was around a 30 m emission source. The sampling arcs were chosen at 150-300 m from the base of the source to minimize dry deposition on the precipitation collectors. Data of the scavenging experiments are presented. Kinetics of HT deposition to soil through its oxidation has been studied in laboratory conditions. The activity of HTO converted in the soil sample during a certain period of time was used to determine the oxidation rate. This rate varies, depending on the catalytic and/or biological activity of the soil material. Theoretical considerations have shown that the deposition rate can be expressed by the effective rate of oxidation, which formally corresponds to the first-order HT oxidation. HT deposition rates are reported. The model, used for assessments, takes into account atmospheric dispersion, deposition and reemission. The model of HTO wet deposition is taken into account kinetics of HTO exchange between vapor and liquid phase with parameters such as rain drop spectra, rain intensity, condensation-evaporation on drop's interface. Gauss type formulae for continuous emission source is used to calculate HTO atmospheric concentration. Meteorological data are used as input parameters for modeling. The data presented on HT deposition to soil and HTO washout by precipitation is required for assessment of consequences of HT (HTO) release into the atmosphere.

  11. Long-term monitoring of a marine geologic hydrocarbon source by a coastal air pollution station in Southern California

    NASA Astrophysics Data System (ADS)

    Bradley, Eliza; Leifer, Ira; Roberts, Dar

    2010-12-01

    Hourly total hydrocarbon (THC) data, spanning 1990-2008 from a California air pollution station located near the Coal Oil Point (COP) seep field, were analyzed and clearly showed geologic CH 4 emissions as the dominant local source. Annual COP emissions are conservatively estimated as 0.015 Tg CH 4 year -1 and represent a natural and concentrated geologic methane source (24 m 3 m -2 day -1 gas flux at some active seeps, Clark et al., 2010). For a sense of the scale and potential importance to the regional Southern California methane budget, COP emits an amount equivalent to 8% of the estimated Los Angeles County anthropogenic emissions. Station THC measurements near COP showed a strong wind dependency with elevated levels closely correlated with a sonar-derived spatial distribution of seep field emissions. THC varied seasonally, with a maximum in January and minimum in July and a peak-to-peak amplitude of 0.24 ppm. The seasonal signal was more readily apparent midday ( R2 = 0.69 harmonic fit), compared to nighttime and morning ( R2 < 0.45). The bimodal diel THC pattern consisted of seasonally-modulated peaks in the morning and evening. THC temporal and spatial trends were consistent with both transport and source emission variations. Long-term, annual seep field emissions consistently decreased on a field-wide basis until the late 1990s, before increasing consistently, most likely as a function of underlying geologic processes. This study demonstrates the value of municipal air quality monitoring stations for insight into local greenhouse gas sources and highlights the non-negligible and variable contribution from marine geologic seepage.

  12. Understanding Mechanisms of Radiological Contamination

    SciTech Connect

    Rick Demmer; John Drake; Ryan James, PhD

    2014-03-01

    Over the last 50 years, the study of radiological contamination and decontamination has expanded significantly. This paper addresses the mechanisms of radiological contamination that have been reported and then discusses which methods have recently been used during performance testing of several different decontamination technologies. About twenty years ago the Idaho Nuclear Technology Engineering Center (INTEC) at the INL began a search for decontamination processes which could minimize secondary waste. In order to test the effectiveness of these decontamination technologies, a new simulated contamination, termed SIMCON, was developed. SIMCON was designed to replicate the types of contamination found on stainless steel, spent fuel processing equipment. Ten years later, the INL began research into methods for simulating urban contamination resulting from a radiological dispersal device (RDD). This work was sponsored by the Defense Advanced Research Projects Agency (DARPA) and included the initial development an aqueous application of contaminant to substrate. Since 2007, research sponsored by the US Environmental Protection Agency (EPA) has advanced that effort and led to the development of a contamination method that simulates particulate fallout from an Improvised Nuclear Device (IND). The IND method diverges from previous efforts to create tenacious contamination by simulating a reproducible “loose” contamination. Examining these different types of contamination (and subsequent decontamination processes), which have included several different radionuclides and substrates, sheds light on contamination processes that occur throughout the nuclear industry and in the urban environment.

  13. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, January 1-March 31, 1981

    SciTech Connect

    Waterbury, G.R.

    1981-09-01

    The containers for /sup 238/PuO/sub 2/ heat souces in radioisotope thermoelectric generators are designed with large safety factors to ensure that they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. The data obtained in several ongoing experiments are presented; these data tables will be updated quarterly. Discussions of experimental details are minimized and largely repetitive in succeeding reports. Compilations of usable data generated in each experiment are emphasized. These compilations include data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO/sub 2/ dissolution rates soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments.

  14. Review of the status of validation of the computer codes used in the severe accident source term reassessment study (BMI-2104). [PWR; BWR

    SciTech Connect

    Kress, T. S.

    1985-04-01

    The determination of severe accident source terms must, by necessity it seems, rely heavily on the use of complex computer codes. Source term acceptability, therefore, rests on the assessed validity of such codes. Consequently, one element of NRC's recent efforts to reassess LWR severe accident source terms is to provide a review of the status of validation of the computer codes used in the reassessment. The results of this review is the subject of this document. The separate review documents compiled in this report were used as a resource along with the results of the BMI-2104 study by BCL and the QUEST study by SNL to arrive at a more-or-less independent appraisal of the status of source term modeling at this time.

  15. An admissibility and asymptotic-preserving scheme for systems of conservation laws with source term on 2D unstructured meshes

    NASA Astrophysics Data System (ADS)

    Blachère, F.; Turpault, R.

    2016-06-01

    The objective of this work is to design explicit finite volumes schemes for specific systems of conservations laws with stiff source terms, which degenerate into diffusion equations. We propose a general framework to design an asymptotic preserving scheme, that is stable and consistent under a classical hyperbolic CFL condition in both hyperbolic and diffusive regime, for any two-dimensional unstructured mesh. Moreover, the scheme developed also preserves the set of admissible states, which is mandatory to keep physical solutions in stiff configurations. This construction is achieved by using a non-linear scheme as a target scheme for the diffusive equation, which gives the form of the global scheme for the complete system of conservation laws. Numerical results are provided to validate the scheme in both regimes.

  16. LU-SGS implicit algorithm for three-dimensional incompressible Navier-Stokes equations with source term

    NASA Technical Reports Server (NTRS)

    Yoon, Seokkwan; Chang, Leon; Kwak, Dochan

    1989-01-01

    A numerical method is developed for solving the incompressible Navier-Stokes equations using the concept of pseudocompressibility. A lower-upper symmetric-Gauss-Seidel implicit scheme is developed for three-dimensional incompressible viscous flow computations. The present algorithm offers additional advantages when solving the flow equations with source terms. Complete vectorizability of the algorithm on oblique planes of sweep in three-dimensions is accomplished in a new flow solver, INS3D-LU code. Spatial differencing is a second-order accurate semi-discrete finite-volume method augmented by a third-order accurate numerical dissipation model which is based on spectral-radii. Comparison of numerical solutions for a curved duct with experimental data shows good agreement. The method is applied to calculate the inducer flow of the Space Shuttle Main Engine turbopump.

  17. Source Term Estimation for Small-Sized HTRs: Status and Further Needs, Extracted from German Safety Analyses

    SciTech Connect

    Moormann, Rainer; Schenk, Werner; Verfondern, Karl

    2001-09-15

    The stringent safety demands for advanced small pebble bed high-temperature reactors (HTRs) are outlined. Main results of German studies on source term estimation are discussed. Core heatup events are no longer dominant for modern fuel, but fission product transport during water ingress accidents (steam cycle plants) and He-circuit depressurizations are relevant, mainly due to remobilization of fission products that were plated out in the course of normal operation or that became dust borne. The following important lack of knowledge was identified: Data on plateout in normal operation are insufficient, as are data on behavior of dust-borne activity in total; better knowledge in these fields is also important for maintenance/repair and design/shielding. For core heatup events, the influence of burnup on temperature-induced fission product release has to be measured for future Pu-containing high burnup fuel; furthermore, transport mechanisms out of the He circuit into the environment require further examination. For water/steam ingress events, mobilization of plated-out fission products by steam or water has to be considered in detail along with steam interaction with kernels of particles with defective coatings. For source terms of depressurization, a more detailed knowledge of flow pattern and shear forces on surfaces is necessary. To improve the knowledge on plateout and dust in normal operation and to generate specimens for experimental remobilization studies, planning/design of plateout/dust examination facilities to be added to HTRs running in the next future reactors [HTR10 and the High-Temperature Engineering Test Reactor (HTTR)] is proposed. For severe air ingress and reactivity accidents, which belong to hypothetical events with frequencies <1 x 10{sup -7} yr{sup -1}, behavior of future advanced fuel elements has to be experimentally tested.

  18. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    SciTech Connect

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

  19. Hazard control indices for radiological and non-radiological materials

    SciTech Connect

    Boothe, G.F.

    1994-12-21

    This document devises a method of comparing radiological and non-radiological hazard control levels. Such a comparison will be useful in determining the design control features for facilities that handle radioactive mixed waste. The design control features of interest are those that assure the protection of workers and the environment from unsafe airborne levels of radiological or non-radiological hazards.

  20. The disaggregation of radiology.

    PubMed

    Brant-Zawadzki, Michael N; Enzmann, Dieter R

    2008-12-01

    The authors discuss certain market and political forces buffeting the traditional structure of radiology, both in practice and in the academic setting. These forces can be, to a certain degree, disruptive and produce fragmentation of what are now integrated radiology services and specialties. The potential fallout from the current rapidly changing environment of health care, including strategies for delivering care along service lines or within discrete episodes of care, may have a profound impact on the future of radiology. Understanding the dynamics of the current environment may help plan strategies for dealing with the potential impact on our specialty. PMID:19027680

  1. Enhanced radiological work planning

    SciTech Connect

    DECKER, W.A.

    1999-05-21

    The purpose of this standard is to provide Project Hanford Management Contractors (PHMC) with guidance for ensuring radiological considerations are adequately addressed throughout the work planning process. Incorporating radiological controls in the planning process is a requirement of the Hanford Site Radiological Control Manual (HSRCM-I), Chapter 3, Part 1. This standard is applicable to all PHMC contractors and subcontractors. The essential elements of this standard will be incorporated into the appropriate site level work control standard upon implementation of the anticipated revision of the PHMC Administration and Procedure System.

  2. Managerial accounting applications in radiology.

    PubMed

    Lexa, Frank James; Mehta, Tushar; Seidmann, Abraham

    2005-03-01

    We review the core issues in managerial accounting for radiologists. We introduce the topic and then explore its application to diagnostic imaging. We define key terms such as fixed cost, variable cost, marginal cost, and marginal revenue and discuss their role in understanding the operational and financial implications for a radiology facility by using a cost-volume-profit model. Our work places particular emphasis on the role of managerial accounting in understanding service costs, as well as how it assists executive decision making. PMID:17411809

  3. 135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

    DOE PAGESBeta

    Snow, Mathew S.; Snyder, Darin C.

    2015-11-02

    135Cs/137Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the 135Cs/137Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product 135Cs/137Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated 135Cs/137Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement withmore » values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show 135Cs/137Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. Furthermore, the differences in 135Cs/137Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that 135Cs/137Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe.« less

  4. (135)Cs/(137)Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications.

    PubMed

    Snow, Mathew S; Snyder, Darin C

    2016-01-01

    (135)Cs/(137)Cs isotopic analyses represent an important tool for studying the fate and transport of radiocesium in the environment; in this work the (135)Cs/(137)Cs isotopic composition in environmental samples taken from across Europe is reported. Surface soil and vegetation samples from western Russia, Ukraine, Austria, and Hungary show consistent aged thermal fission product (135)Cs/(137)Cs isotope ratios of 0.58 ± 0.01 (age corrected to 1/1/15), with the exception of one sample of soil-moss from Hungary which shows an elevated (135)Cs/(137)Cs ratio of 1.78 ± 0.12. With the exception of the outlier sample from Hungary, surface soil/vegetation data are in quantitative agreement with values previously reported for soils within the Chernobyl exclusion zone, suggesting that radiocesium at these locations is primarily composed of homogenous airborne deposition from Chernobyl. Seawater samples taken from the Irish Sea show (135)Cs/(137)Cs isotope ratios of 1.22 ± 0.11 (age corrected to 1/1/15), suggesting aged thermal fission product Cs discharged from Sellafield. The differences in (135)Cs/(137)Cs isotope ratios between Sellafield, Chernobyl, and global nuclear weapons testing fallout indicate that (135)Cs/(137)Cs isotope ratios can be utilized to discriminate between and track radiocesium transport from different nuclear production source terms, including major emission sources in Europe. PMID:26540258

  5. Long-term natural attenuation of carbon and nitrogen within a groundwater plume after removal of the treated wastewater source

    USGS Publications Warehouse

    Repert, D.A.; Barber, L.B.; Hess, K.M.; Keefe, S.H.; Kent, D.B.; LeBlanc, D.R.; Smith, R.L.

    2006-01-01

    Disposal of treated wastewater for more than 60 years onto infiltration beds on Cape Cod, Massachusetts produced a groundwater contaminant plume greater than 6 km long in a surficial sand and gravel aquifer. In December 1995 the wastewater disposal ceased. A long-term, continuous study was conducted to characterize the post-cessation attenuation of the plume from the source to 0.6 km downgradient. Concentrations and total pools of mobile constituents, such as boron and nitrate, steadily decreased within 1-4 years along the transect. Dissolved organic carbon loads also decreased, but to a lesser extent, particularly downgradient of the infiltration beds. After 4 years, concentrations and pools of carbon and nitrogen in groundwater were relatively constant with time and distance, but substantially elevated above background. The contaminant plume core remained anoxic for the entire 10-year study period; temporal patterns of integrated oxygen deficit decreased slowly at all sites. In 2004, substantial amounts of total dissolved carbon (7 mol C m-2) and fixed (dissolved plus sorbed) inorganic nitrogen (0.5 mol N m-2) were still present in a 28-m vertical interval at the disposal site. Sorbed constituents have contributed substantially to the dissolved carbon and nitrogen pools and are responsible for the long-term persistence of the contaminant plume. Natural aquifer restoration at the discharge location will take at least several decades, even though groundwater flow rates and the potential for contaminant flushing are relatively high.

  6. Long-term agricultural non-point source pollution loading dynamics and correlation with outlet sediment geochemistry

    NASA Astrophysics Data System (ADS)

    Ouyang, Wei; Jiao, Wei; Li, Xiaoming; Giubilato, Elisa; Critto, Andrea

    2016-09-01

    Some agricultural non-point source (NPS) pollutants accumulate in sediments in the outlet sections of watersheds. It is crucial to evaluate the historical interactions between sediment properties and watershed NPS loading. Therefore, a sediment core from the outlet of an agricultural watershed was collected. The core age was dated using the 210Pb method, and sedimentation rates were determined using the constant rate of supply (CRS) model. The total nitrogen (TN), total phosphorus (TP), Cd, Pb, Cu, Ni and Cr accumulations in the sediment generally showed fluctuating increases, with the highest sedimentation fluxes all occurring in approximately 1998. The measurement of specific mass sedimentation rates reflected a record of watershed soil erosion dynamics. Using SWAT (Soil and Water Assessment Tool) to simulate long-term watershed agricultural NPS pollution loadings, the historical interactions between sediment properties and NPS loadings were further evaluated. The N leaching process weakened these interactions, but the historical accumulations of TP and heavy metals in sediments generally correlated well with watershed NPS TP loading. The regression analysis suggested that Pb and Cr were the most suitable indexes for assessing long-term NPS TN and TP pollution, respectively. Assessing the NPS loading dynamics using the vertical characteristics of sediment geochemistry is a new method.

  7. Sources of atmospheric aerosol from long-term measurements (5 years) of chemical composition in Athens, Greece.

    PubMed

    Paraskevopoulou, D; Liakakou, E; Gerasopoulos, E; Mihalopoulos, N

    2015-09-15

    To identify the sources of aerosols in Greater Athens Area (GAA), a total of 1510 daily samples of fine (PM 2.5) and coarse (PM 10-2,5) aerosols were collected at a suburban site (Penteli), during a five year period (May 2008-April 2013) corresponding to the period before and during the financial crisis. In addition, aerosol sampling was also conducted in parallel at an urban site (Thissio), during specific, short-term campaigns during all seasons. In all these samples mass and chemical composition measurements were performed, the latest only at the fine fraction. Particulate organic matter (POM) and ionic masses (IM) are the main contributors of aerosol mass, equally contributing by accounting for about 24% of the fine aerosol mass. In the IM, nss-SO4(-2) is the prevailing specie followed by NO3(-) and NH4(+) and shows a decreasing trend during the 2008-2013 period similar to that observed for PM masses. The contribution of water in fine aerosol is equally significant (21 ± 2%), while during dust transport, the contribution of dust increases from 7 ± 2% to 31 ± 9%. Source apportionment (PCA and PMF) and mass closure exercises identified the presence of six sources of fine aerosols: secondary photochemistry, primary combustion, soil, biomass burning, sea salt and traffic. Finally, from winter 2012 to winter 2013 the contribution of POM to the urban aerosol mass is increased by almost 30%, reflecting the impact of wood combustion (dominant fuel for domestic heating) to air quality in Athens, which massively started in winter 2013. PMID:25958364

  8. Long- and short-term flooding effects on survival and sink-source relationships of swamp-adapted tree species.

    PubMed

    Angelov, M N; Sung, S J; Doong, R L; Harms, W R; Kormanik, P P; Black Jr, C C

    1996-05-01

    About 95% of swamp tupelo (Nyssa sylvatica var. biflora (Walt.) Sarg.) and sweetgum (Liquidambar styraciflua L.) seedlings survived continuous root flooding for more than two years, whereas none of the swamp chestnut oak (Quercus michauxii Nutt.) and cherrybark oak (Q. falcata var. pagodifolia Ell.) seedlings survived one year of flooding. Death of oak seedlings occurred in phases associated with periods of major vegetative growth, e.g., after bud burst in spring, after summer stem elongation, and during the winter deciduous stage, suggesting that stored reserves and sources were inadequate to maintain the seedlings when vegetative sinks were forming. Additional evidence that flooding induced a source deficiency in oak was that leaves of flooded oak were 65 to 75% smaller than leaves of nonflooded oak. Flooded swamp tupelo seedlings had a normal leaf size and patchy stomatal opening compared with nonflooded seedlings. Flooding caused increases in alcohol dehydrogenase (ADH) specific activity in taproot cambial tissues and increases in starch concentrations of swamp tupelo seedlings that were reversed when seedlings were removed from flooding. Flooding had little effect on soluble sugar concentrations in swamp tupelo or sweetgum. In the long-term flood-dry-flood treatment, in which all species had survivors, upper canopy leaf photosynthetic rates were higher in all species during the dry period than in nonflooded controls, whereas their starch and soluble sugars concentrations were similar to those of nonflooded controls. Based on seedling survival and the sink-source relationships, the order of flood tolerance was: swamp tupelo > sweetgum > swamp chestnut oak > cherrybark oak. PMID:14871716

  9. Detecting long-term changes in point-source fossil CO2 emissions with tree ring archives

    NASA Astrophysics Data System (ADS)

    Keller, Elizabeth D.; Turnbull, Jocelyn C.; Norris, Margaret W.

    2016-05-01

    We examine the utility of tree ring 14C archives for detecting long-term changes in fossil CO2 emissions from a point source. Trees assimilate carbon from the atmosphere during photosynthesis, in the process faithfully recording the average atmospheric 14C content in each new annual tree ring. Using 14C as a proxy for fossil CO2, we examine interannual variability over six years of fossil CO2 observations between 2004-2005 and 2011-2012 from two trees growing near the Kapuni Gas Treatment Plant in rural Taranaki, New Zealand. We quantify the amount of variability that can be attributed to transport and meteorology by simulating constant point-source fossil CO2 emissions over the observation period with the atmospheric transport model WindTrax. We compare model simulation results to observations and calculate the amount of change in emissions that we can detect with new observations over annual or multi-year time periods, given both the measurement uncertainty of 1ppm and the modelled variation in transport. In particular, we ask, what is the minimum amount of change in emissions that we can detect using this method, given a reference period of six years? We find that changes of 42 % or more could be detected in a new sample from one year at the same observation location or 22 % in the case of four years of new samples. This threshold is reduced and the method becomes more practical the more the size of the signal increases. For point sources 10 times larger than the Kapuni plant (a more typical size for power plants worldwide), it would be possible to detect sustained emissions changes on the order of 10 %, given suitable meteorology and observations.

  10. A long term source apportionment study of wood burning and traffic aerosols for three measurement sites in Switzerland

    NASA Astrophysics Data System (ADS)

    Herich, Hanna; Hüglin, Christoph; Buchmann, Brigitte

    2010-05-01

    Besides their effects on radiative forcing soot aerosols have been found to cause health effects as they are carcinogenic. Diesel engines and incomplete biomass burning are the major emission sources of soot particles. Especially during winter, the wood burning (WB) emissions from residential heating have been found to contribute significantly to the total carbonaceous material (CM). To investigate the contribution of fossil fuel (FF) and WB emissions seven-wavelength aethalometers have been deployed in previous studies (Sandradewi et al. 2008, Favez et al. 2009). In these studies, the stronger light absorption of WB aerosols in the blue and ultraviolet compared to the light absorption of aerosols from FF combustion was used. Linear regression modelling of CM against the light absorption coefficient of FF combustion aerosols in the infrared (950 nm) and the light absorption coefficient of WB aerosols in the blue (470 nm) was proposed for source apportionment. In this study we present long term aethalometer measurements at two rural and one urban background measurement stations in Switzerland from 2008 - 2010. At these stations organic (OC) and elemental carbon (EC) were also measured by thermochemical analysis providing estimates for total CM. Above described linear regession modelling was applied for determination of the contribution of FF and WB emissions to total CM. Sensitivity tests for different regression models and for varying light absorption exponents were performed. It was found that the regression modelling approach is only limited suitable for long term datasets because of significant fractions of CM resulting from sources and processes other than FF and WB. Thus in a different approach we focused on black carbon (BC). The contribution of WB and FF to BC was directly determined from the absorption coefficients of FF and WB aerosols which were calculated with the use of absorption exponents taken from literature. First results show that in winter the

  11. Radiological considerations for POE-1 photon shutters, collimators and beam stops of the Biomedical Imaging and Therapy beamline at the Canadian Light Source

    NASA Astrophysics Data System (ADS)

    Asai, Juhachi; Wysokinski, Tomasz W.; Smith, Sheldon; Chapman, Dean

    2008-01-01

    A study of radiation levels due to primary and secondary gas bremsstrahlung is carried out for the BioMedical Imaging and Therapy (BMIT) beamline at the Canadian Light Source (CLS). The BMIT beamline, being built at present, is a major research and diagnostic tool for X-ray imaging and X-ray radiation therapy for animals and humans. For the BMIT beamline to be as flexible as possible, a movable tungsten collimator is designed. This can move vertically and assumes two positions; up and down. The BMIT beamline is, thus, able to perform two modes of operation: one white beam, the other monochromatic. Gas bremsstrahlung produced in the vacuum chamber propagates with synchrotron radiation and may enter the imaging or therapy hutch. In this study, the dose behind the collimator is investigated in each mode by assessing the energy deposition in a water phantom that surrounds the entire copper shutter-tungsten collimator unit. When estimating the dose, particular attention is given to the opening area of the collimator, since this passage leads to the imaging or therapy hutch. Also examined are the doses when a tungsten safety shutter is closed.

  12. 3.3 Diagnostic Radiology

    NASA Astrophysics Data System (ADS)

    Kramer, H.-M.; Moores, B. M.; Stieve, F.-E.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '3.3 Diagnostic Radiology' of the Chapter '3 Dosimetry in Diagnostic Radiology and Radiotherapy' with the contents:

  13. Radiologic Technology Program Standards.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This publication contains statewide standards for the radiologic technology program in Georgia. The standards are divided into 12 categories; Foundations (philosophy, purpose, goals, program objectives, availability, evaluation); Admissions (admission requirements, provisional admission requirements, recruitment, evaluation and planning); Program…

  14. Society of Interventional Radiology

    MedlinePlus

    ... how interventional radiology research improves patients’ lives at Society of Interventional Radiology’s 2017 Annual Scientific Meeting; read ... comments to CMS on two MACRA coding issues; society is engaged with CMS as they develop codes ...

  15. Analysis of accident sequences and source terms at waste treatment and storage facilities for waste generated by U.S. Department of Energy Waste Management Operations, Volume 1: Sections 1-9

    SciTech Connect

    Mueller, C.; Nabelssi, B.; Roglans-Ribas, J.

    1995-04-01

    This report documents the methodology, computational framework, and results of facility accident analyses performed for the U.S. Department of Energy (DOE) Waste Management Programmatic Environmental Impact Statement (WM PEIS). The accident sequences potentially important to human health risk are specified, their frequencies are assessed, and the resultant radiological and chemical source terms are evaluated. A personal computer-based computational framework and database have been developed that provide these results as input to the WM PEIS for calculation of human health risk impacts. The methodology is in compliance with the most recent guidance from DOE. It considers the spectrum of accident sequences that could occur in activities covered by the WM PEIS and uses a graded approach emphasizing the risk-dominant scenarios to facilitate discrimination among the various WM PEIS alternatives. Although it allows reasonable estimates of the risk impacts associated with each alternative, the main goal of the accident analysis methodology is to allow reliable estimates of the relative risks among the alternatives. The WM PEIS addresses management of five waste streams in the DOE complex: low-level waste (LLW), hazardous waste (HW), high-level waste (HLW), low-level mixed waste (LLMW), and transuranic waste (TRUW). Currently projected waste generation rates, storage inventories, and treatment process throughputs have been calculated for each of the waste streams. This report summarizes the accident analyses and aggregates the key results for each of the waste streams. Source terms are estimated and results are presented for each of the major DOE sites and facilities by WM PEIS alternative for each waste stream. The appendices identify the potential atmospheric release of each toxic chemical or radionuclide for each accident scenario studied. They also provide discussion of specific accident analysis data and guidance used or consulted in this report.

  16. Radiological Monitoring for Instructors. Student Workbook. Revised.

    ERIC Educational Resources Information Center

    Office of Civil Defense (DOD), Washington, DC.

    This student workbook includes the necessary materials and some of the references needed by each student during the conduct of the Radiological Monitoring for Instructors (RMI) course. The contents include a radiation exposure record, instrument exercise materials, fallout forecasting problems, dose and dose rate problems, source handling…

  17. Interventional Radiology in China

    SciTech Connect

    Teng Gaojun Xu Ke; Ni Caifang; Li Linsun

    2008-03-15

    With more than 3000 members, the Chinese Society of Interventional Radiology (CSIR) is one of the world's largest societies for interventional radiology (IR). Nevertheless, compared to other societies such as CIRSE and SIR, the CSIR is a relatively young society. In this article, the status of IR in China is described, which includes IR history, structure and patient management, personnel, fellowship, training, modalities, procedures, research, turf battle, and insightful visions for IR from Chinese interventional radiologists.

  18. Basic bone radiology

    SciTech Connect

    Griffiths, H.J.

    1987-01-01

    This clinical book surveys the skeletal system as seen through radiological imaging. It emphasizing abnormalities, disease, and trauma, and includes vital information on bones, bone growth, and the cells involved in bone pathology. It covers many bone diseases and injuries which are rarely covered in medical texts, as well as descriptions of radiologic procedures that specifically relate to the skeleton. This edition includes many illustrations, information on MR imaging and CT scanning, and discussions of osteoporosis, dysplasias, and metabolic bone disease.

  19. [Instruction in dental radiology].

    PubMed

    van der Sanden, W J M; Kreulen, C M; Berkhout, W E R

    2016-04-01

    The diagnostic use of oral radiology is an essential part of daily dental practice. Due to the potentially harmful nature of ionising radiation, the clinical use of oral radiology in the Netherlands is framed by clinical practice guidelines and regulatory requirements. Undergraduate students receive intensive theoretical and practical training in practical and theoretical radiology, with the aim of obtaining the 'Eindtermen Stralingshygiëne voor Tandartsen en Orthodontisten'-certificate, which is required for legal permission to use oral radiology in dental practice. It is recommended that the curriculum be expanded to include the areas of knowledge required to qualify for the 'Eindtermen Stralingshygiëne voor het gebruik van CBCT-toestellen door tandartsen' (the certificate for the use of conebeam radiology by dentists). The general dental practitioner is faced with changing laws and regulations in all areas of practice. One of the most significant legal changes in the field of dental radiology was the introduction of the new radiation protection and safety rules in 2014. Moreover, a large group of dentists is also being confronted with the transition from conventional to digital images, with all its challenges and changes in everyday practice. PMID:27073811

  20. DOE standard: Radiological control

    SciTech Connect

    Not Available

    1999-07-01

    The Department of Energy (DOE) has developed this Standard to assist line managers in meeting their responsibilities for implementing occupational radiological control programs. DOE has established regulatory requirements for occupational radiation protection in Title 10 of the Code of Federal Regulations, Part 835 (10 CFR 835), ``Occupational Radiation Protection``. Failure to comply with these requirements may lead to appropriate enforcement actions as authorized under the Price Anderson Act Amendments (PAAA). While this Standard does not establish requirements, it does restate, paraphrase, or cite many (but not all) of the requirements of 10 CFR 835 and related documents (e.g., occupational safety and health, hazardous materials transportation, and environmental protection standards). Because of the wide range of activities undertaken by DOE and the varying requirements affecting these activities, DOE does not believe that it would be practical or useful to identify and reproduce the entire range of health and safety requirements in this Standard and therefore has not done so. In all cases, DOE cautions the user to review any underlying regulatory and contractual requirements and the primary guidance documents in their original context to ensure that the site program is adequate to ensure continuing compliance with the applicable requirements. To assist its operating entities in achieving and maintaining compliance with the requirements of 10 CFR 835, DOE has established its primary regulatory guidance in the DOE G 441.1 series of Guides. This Standard supplements the DOE G 441.1 series of Guides and serves as a secondary source of guidance for achieving compliance with 10 CFR 835.

  1. Protégé: a tool for managing and using terminology in radiology applications.

    PubMed

    Rubin, Daniel L; Noy, Natalya F; Musen, Mark A

    2007-11-01

    The development of standard terminologies such as RadLex is becoming important in radiology applications, such as structured reporting, teaching file authoring, report indexing, and text mining. The development and maintenance of these terminologies are challenging, however, because there are few specialized tools to help developers to browse, visualize, and edit large taxonomies. Protégé ( http://protege.stanford.edu ) is an open-source tool that allows developers to create and to manage terminologies and ontologies. It is more than a terminology-editing tool, as it also provides a platform for developers to use the terminologies in end-user applications. There are more than 70,000 registered users of Protégé who are using the system to manage terminologies and ontologies in many different domains. The RadLex project has recently adopted Protégé for managing its radiology terminology. Protégé provides several features particularly useful to managing radiology terminologies: an intuitive graphical user interface for navigating large taxonomies, visualization components for viewing complex term relationships, and a programming interface so developers can create terminology-driven radiology applications. In addition, Protégé has an extensible plug-in architecture, and its large user community has contributed a rich library of components and extensions that provide much additional useful functionalities. In this report, we describe Protégé's features and its particular advantages in the radiology domain in the creation, maintenance, and use of radiology terminology. PMID:17687607

  2. Analysis of positron annihilation lifetime data by numerical Laplace inversion: Corrections for source terms and zero-time shift errors

    NASA Astrophysics Data System (ADS)

    Gregory, Roger B.

    1991-05-01

    We have recently described modifications to the program CONTIN [S.W. Provencher, Comput. Phys. Commun. 27 (1982) 229] for the solution of Fredholm integral equations with convoluted kernels of the type that occur in the analysis of positron annihilation lifetime data [R.B. Gregory and Yongkang Zhu, Nucl. Instr. and Meth. A290 (1990) 172]. In this article, modifications to the program to correct for source terms in the sample and reference decay curves and for shifts in the position of the zero-time channel of the sample and reference data are described. Unwanted source components, expressed as a discrete sum of exponentials, may be removed from both the sample and reference data by modification of the sample data alone, without the need for direct knowledge of the instrument resolution function. Shifts in the position of the zero-time channel of up to half the channel width of the multichannel analyzer can be corrected. Analyses of computer-simulated test data indicate that the quality of the reconstructed annihilation rate probability density functions is improved by employing a reference material with a short lifetime and indicate that reference materials which generate free positrons by quenching positronium formation (i.e. strong oxidizing agents) have lifetimes that are too long (400-450 ps) to provide reliable estimates of the lifetime parameters for the shortlived components with the methods described here. Well-annealed single crystals of metals with lifetimes less than 200 ps, such as molybdenum (123 ps) and aluminum (166 ps) do not introduce significant errors in estimates of the lifetime parameters and are to be preferred as reference materials. The performance of our modified version of CONTIN is illustrated by application to positron annihilation in polytetrafluoroethylene.

  3. Aerosol climatology at Delhi in the western Indo-Gangetic Plain: Microphysics, long-term trends, and source strengths

    NASA Astrophysics Data System (ADS)

    Lodhi, Neelesh K.; Beegum, S. Naseema; Singh, Sachchidanand; Kumar, Krishan

    2013-02-01

    present the climatology of aerosol microphysics, its trends, and impact of potential sources based on the long term measurements (for a period of 11.5 years from December 2001 to May 2012) of aerosol optical depths (AOD) in the spectral range 340-1020 nm from an urban center Delhi (28.6°N, 77.3°E, 238 m mean sea level) in the western Indo-Gangetic Plain (IGP). The study is the first ever long-term characterization of aerosols over the western IGP from the ground-based measurements. AODs are known to affect the air quality, visibility, radiative balance, and cloud microphysics of the region and IGP is one of the highest populated and polluted regions of the world. Our measurements show consistently high AOD during the entire period of observation. The seasonal variations of spectral AODs and Angstrom parameters are generally consistent every year. The AODs show a weak but statistically significant (in 95% confidence level) decreasing trend approximately -0.02/year at 500 nm, possibly, modulated by the pre-monsoon heavy dust loading during the first half of the observation period. The climatological monthly mean AOD at shorter wavelengths peaks twice, during June and November, while at longer wavelengths it shows only one peak in June. The annual variations of Angstrom exponent, α and its derivative, α' suggest the prevalence of multi-modal aerosol size distributions at Delhi. The coarse-mode aerosols dominate during summer (March-June) and monsoon (July-September) seasons, whereas fine/accumulation mode enhances during post-monsoon (October-November) and winter (December-February) seasons. Potential advection pathways have been identified using concentration weighted trajectory (CWT) analysis of the 5 day isentropic air mass back trajectories at the observation site and their seasonal variations are discussed.

  4. Long-term effects of organic and inorganic nutrient sources on soil organic carbon and major nutrients in Vertisols

    NASA Astrophysics Data System (ADS)

    Aladakatti, Y. R.; Hallikeri, S. S.; Nandagavi, R. A.

    2012-04-01

    Field experiment conducted over 10 years at the University of Agricultural Sciences, Dharwad, India, assessed the long-term effects of various sources of organics (farmyard manure {FYM}, vermicompost and cotton crop residue) in conjunction with graded levels of inorganic fertilizers on the soil organic carbon (SOC), available major nutrients and seed cotton yield in cotton- (groundnut - winter Sorghum) rotation system. Main plots comprised FYM (10 Mg/ha), vermicompost (2.5 Mg/ha), cotton crop residue (2.5 Mg/ha) and combination of these organics in various proportions with an absolute control (no organics). No inorganic fertilizes, 50 and 100 % of the recommended dose of fertilizers (RDF) were assigned to the sub plots. The organics were applied every year during rainy season and the inorganic fertilizers as per the University recommended dose to each crop. Initial SOC, available N, P and K were 0.68%, 220, 22.5 and 403 kg/ha, respectively. Results indicated that at the end of tenth year of crop rotation, application of FYM, vermicompost and cotton crop residue either alone or in combination increased the SOC (0.68 to 0.81%), available N (220 to 308 kg/ha), P (22.5 to 33.0 kg/ha) and K (403 to 530 kg/ha) compared to the control plot where no organics were applied. SOC in the control treatment decreased to 0.52% at the end of tenth year from 0.68%. Averaged over five cropping cycles, application of FYM gave significantly higher yields of seed cotton, groundnut pods and sorghum grain over all other organic sources. During fifth cycle of cotton crop or 10th year of rotation, application of FYM along with 100% RDF resulted in the highest productivity and was similar to FYM + 50 % RDF, indicating a saving of 50% chemical fertilizer in these crops. Combination of cotton crop residue and vermicompost were next best alternative sources of organics after FYM in order of preference. Our studies suggest that in the scarcity of good quality manure such as FYM, cotton crop

  5. Cost of presumptive source term Remedial Actions Laboratory for energy-related health research, University of California, Davis

    SciTech Connect

    Last, G.V.; Bagaasen, L.M.; Josephson, G.B.; Lanigan, D.C.; Liikala, T.L.; Newcomer, D.R.; Pearson, A.W.; Teel, S.S.

    1995-12-01

    A Remedial Investigation/Feasibility Study (RI/FS) is in progress at the Laboratory for Energy Related Health Research (LEHR) at the University of California, Davis. The purpose of the RI/FS is to gather sufficient information to support an informed risk management decision regarding the most appropriate remedial actions for impacted areas of the facility. In an effort to expedite remediation of the LEHR facility, the remedial project managers requested a more detailed evaluation of a selected set of remedial actions. In particular, they requested information on both characterization and remedial action costs. The US Department of Energy -- Oakland Office requested the assistance of the Pacific Northwest National Laboratory to prepare order-of-magnitude cost estimates for presumptive remedial actions being considered for the five source term operable units. The cost estimates presented in this report include characterization costs, capital costs, and annual operation and maintenance (O&M) costs. These cost estimates are intended to aid planning and direction of future environmental remediation efforts.

  6. High Order Well-Balanced Schemes and Applications to Non-Equilibrium Flow with Stiff Source Terms

    SciTech Connect

    Wang, W; Shu, C; Yee, H C; Sjogreen, B

    2009-01-14

    The stiffness of the source terms in modeling non-equilibrium flow problems containing finite-rate chemistry or combustion poses additional numerical difficulties beyond that for solving non-reacting flows. A well-balanced scheme, which can preserve certain non-trivial steady state solutions exactly, may help to resolve some of these difficulties. In this paper, a simple one dimensional non-equilibrium model with one temperature is considered. We first describe a general strategy to design high order well-balanced finite difference schemes and then study the well-balanced properties of high order finite difference weighted essentially non-oscillatory (WENO) scheme, modified balanced WENO schemes and various TVD schemes. The advantages of using a well-balanced scheme in preserving steady states and in resolving small perturbations of such states will be shown. Additional numerical examples are provided to verify the good resolution, in addition to the well-balancedness, for both smooth and discontinuous solutions as well.

  7. Impact factors on the long-term sustainability of Borehole Heat Exchanger coupled Ground Source Heat Pump System

    NASA Astrophysics Data System (ADS)

    Shao, Haibing; Hein, Philipp; Görke, Uwe-Jens; Bucher, Anke; Kolditz, Olaf

    2016-04-01

    In recent years, Ground Source Heat Pump System (GSHPS) has been recognized as an efficient technology to utilize shallow geothermal energy. Along with its wide application, some GSHPS are experiencing a gradual decrease in Borehole Heat Exchanger (BHE) outflow temperatures and thus have to be turned off after couple of years' operation. A comprehensive numerical investigation was then performed to model the flow and heat transport processes in and around the BHE, together with the dynamic change of heat pump efficiency. The model parameters were based on the soil temperature and surface weather condition in the Leipzig area. Different scenarios were modelled for a service life of 30 years, to reveal the evolution of BHE outflow and surrounding soil temperatures. It is found that lateral groundwater flow and using BHE for cooling will be beneficial to the energy recovery, along with the efficiency improvement of the heat pump. In comparison to other factors, the soil heat capacity and thermal conductivity are considered to have minor impact on the long-term sustainability of the system. Furthermore, the application of thermally enhanced grout material will improve the sustainability and efficiency. In contrast, it is very likely that undersized systems and improper grouting are the causes of strong system degradation.

  8. From Missing Source to Missing Sink: Long-Term Changes in the Nitrogen Budget of a Northern Hardwood Forest

    PubMed Central

    2013-01-01

    Biogeochemical monitoring for 45 years at the Hubbard Brook Experimental Forest in New Hampshire has revealed multiple surprises, seeming contradictions, and unresolved questions in the long-term record of ecosystem nitrogen dynamics. From 1965 to 1977, more N was accumulating in living biomass than was deposited from the atmosphere; the “missing” N source was attributed to biological fixation. Since 1992, biomass accumulation has been negligible or even negative, and streamwater export of dissolved inorganic N has decreased from ∼4 to ∼1 kg of N ha–1 year–1, despite chronically elevated atmospheric N deposition (∼7 kg of N ha–1 year–1) and predictions of N saturation. Here we show that the ecosystem has shifted to a net N sink, either storing or denitrifying ∼8 kg of N ha–1 year–1. Repeated sampling over 25 years shows that the forest floor is not detectably accumulating N, but the C:N ratio is increasing. Mineral soil N has decreased nonsignificantly in recent decades, but the variability of these measurements prevents detection of a change of <700 kg of N ha–1. Whether the excess N is accumulating in the ecosystem or lost through denitrification will be difficult to determine, but the distinction has important implications for the local ecosystem and global climate. PMID:24050261

  9. Use of Source Term and Air Dispersion Modeling in Planning Demolition of Highly Alpha-Contaminated Buildings

    SciTech Connect

    Droppo, James G.; Napier, Bruce A.; Rishel, Jeremy P.; Bloom, Richard W.

    2011-06-22

    The current cleanup of structures related to cold-war production of nuclear materials includes the need to demolish a number of highly alpha-contaminated structures. The process of planning for the demolition of such structures includes unique challenges related to ensuring the protection of both workers and the public. Pre-demolition modeling analyses were conducted to evaluate potential exposures resulting from the proposed demolition of a number of these structures. Estimated emission rates of transuranic materials during demolition are used as input to an air-dispersion model. The climatological frequencies of occurrence of peak air and surface exposures at locations of interest are estimated based on years of hourly meteorological records. The modeling results indicate that downwind deposition is the main operational limitation for demolition of a highly alpha-contaminated building. The pre-demolition modeling directed the need for better contamination characterization and/or different demolition methods—and in the end, provided a basis for proceeding with the planned demolition activities. Post-demolition modeling was also conducted for several contaminated structures, based on the actual demolition schedule and conditions. Comparisons of modeled and monitoring results are shown. Recent monitoring data from the demolition of a UO3 plant shows increments in concentrations that were previously identified in the pre-demolition modeling predictions; these comparisons confirm the validity and value of the pre-demolition source-term and air dispersion computations for planning demolition activities for other buildings with high levels of radioactive contamination.

  10. The radiology assistant: a contrarian's view.

    PubMed

    Baker, Stephen R; Merkulov, Alex

    2005-06-01

    Recent and rapid increases in the utilization of diagnostic imaging have not been matched by concomitant additions to the supply of radiologists and radiology technologists. One proposal to alleviate an expected worsening of this emerging workforce crisis is to create a new job category, the radiology assistant (RA), encompassing a roster of enhanced capabilities that would allow the radiologists to divest themselves of some of their non-interpretative duties with respect to the performance of imaging tests. Through the collaborative efforts of the American College of Radiology and the American Society of Radiology Technologists a nationally recognized, baccalaureate-level curriculum has been designed for the training of RAs. A centerpiece of the curriculum is instruction in fluoroscopy. However, examinations of the GI tract by fluoroscopy are rapidly declining in frequency, raising doubt about the enhanced value an RA would bring to a radiology practice in the near future and worries about encroachment on the range of radiologists' responsibilities over the long term. PMID:16133603

  11. Radiology's value chain.

    PubMed

    Enzmann, Dieter R

    2012-04-01

    A diagnostic radiology value chain is constructed to define its main components, all of which are vulnerable to change, because digitization has caused disaggregation of the chain. Some components afford opportunities to improve productivity, some add value, while some face outsourcing to lower labor cost and to information technology substitutes, raising commoditization risks. Digital image information, because it can be competitive at smaller economies of scale, allows faster, differential rates of technological innovation of components, initiating a centralization-to-decentralization technology trend. Digitization, having triggered disaggregation of radiology's professional service model, may soon usher in an information business model. This means moving from a mind-set of "reading images" to an orientation of creating and organizing information for greater accuracy, faster speed, and lower cost in medical decision making. Information businesses view value chain investments differently than do small professional services. In the former model, producing a better business product will extend image interpretation beyond a radiologist's personal fund of knowledge to encompass expanding external imaging databases. A follow-on expansion with integration of image and molecular information into a report will offer new value in medical decision making. Improved interpretation plus new integration will enrich and diversify radiology's key service products, the report and consultation. A more robust, information-rich report derived from a "systems" and "computational" radiology approach will be facilitated by a transition from a professional service to an information business. Under health care reform, radiology will transition its emphasis from volume to greater value. Radiology's future brightens with the adoption of a philosophy of offering information rather than "reads" for decision making. Staunchly defending the status quo via turf wars is unlikely to constitute a

  12. Revision of earthquake hypocenter locations in GEOFON bulletin data using global source-specific station terms technique

    NASA Astrophysics Data System (ADS)

    Nooshiri, N.; Saul, J.; Heimann, S.; Tilmann, F. J.; Dahm, T.

    2015-12-01

    The use of a 1D velocity model for seismic event location is often associated with significant travel-time residuals. Particularly for regional stations in subduction zones, where the velocity structure strongly deviates from the assumed 1D model, residuals of up to ±10 seconds are observed even for clear arrivals, which leads to strongly biased locations. In fact, due to mostly regional travel-time anomalies, arrival times at regional stations do not match the location obtained with teleseismic picks, and vice versa. If the earthquake is weak and only recorded regionally, or if fast locations based on regional stations are needed, the location may be far off the corresponding teleseismic location. In this case, implementation of travel-time corrections may leads to a reduction of the travel-time residuals at regional stations and, in consequence, significantly improve the relative location accuracy. Here, we have extended the source-specific station terms (SSST) technique to regional and teleseismic distances and adopted the algorithm for probabilistic, non-linear, global-search earthquake location. The method has been applied to specific test regions using P and pP phases from the GEOFON bulletin data for all available station networks. By using this method, a set of timing corrections has been calculated for each station varying as a function of source position. In this way, an attempt is made to correct for the systematic errors, introduced by limitations and inaccuracies in the assumed velocity structure, without solving for a new earth model itself. In this presentation, we draw on examples of the application of this global SSST technique to relocate earthquakes from the Tonga-Fiji subduction zone and from the Chilean margin. Our results have been showing a considerable decrease of the root-mean-square (RMS) residual in earthquake location final catalogs, a major reduction of the median absolute deviation (MAD) of the travel

  13. Radiological worker training

    SciTech Connect

    1998-10-01

    This Handbook describes an implementation process for core training as recommended in Implementation Guide G441.12, Radiation Safety Training, and as outlined in the DOE Radiological Control Standard (RCS). The Handbook is meant to assist those individuals within the Department of Energy, Managing and Operating contractors, and Managing and Integrating contractors identified as having responsibility for implementing core training recommended by the RCS. This training is intended for radiological workers to assist in meeting their job-specific training requirements of 10 CFR 835. While this Handbook addresses many requirements of 10 CFR 835 Subpart J, it must be supplemented with facility-specific information to achieve full compliance.

  14. Westinghouse radiological containment guide

    SciTech Connect

    Aitken, S.B.; Brown, R.L.; Cantrell, J.R.; Wilcox, D.P.

    1994-03-01

    This document provides uniform guidance for Westinghouse contractors on the implementation of radiological containments. This document reflects standard industry practices and is provided as a guide. The guidance presented herein is consistent with the requirements of the DOE Radiological Control Manual (DOE N 5480.6). This guidance should further serve to enable and encourage the use of containments for contamination control and to accomplish the following: Minimize personnel contamination; Prevent the spread of contamination; Minimize the required use of protective clothing and personal protective equipment; Minimize the generation of waste.

  15. Successful Transformational Radiology Leaders.

    PubMed

    Douget, Karen

    2015-01-01

    Transformational radiology leaders elevate subordinates, expand self-awareness, develop lasting relationships, strive to exceed expectations, and uphold the vision and goals of the organization. In order for radiology leaders to become more transformational in their leadership style there are four fundamental elements they must learn: idealized influence, individualized consideration, inspirational motivation, and intellectual stimulation. Leaders can utilize personality and self-assessments to learn more about themselves, identify areas of strengths and weaknesses, and learn to be more effective when leading employees. PMID:26710553

  16. Transplants of immunologically isolated xenogeneic chromaffin cells provide a long-term source of pain-reducing neuroactive substances.

    PubMed

    Sagen, J; Wang, H; Tresco, P A; Aebischer, P

    1993-06-01

    Adrenal medullary chromaffin cells are a potential source of neuroactive substances for transplantation into the CNS to alleviate neurochemical deficits. In particular, work in our laboratory has suggested that adrenal medullary transplants in the spinal subarachnoid space can alleviate pain by providing sustained local delivery of catecholamines and opioid peptides. One of the major limitations for clinical application of neural transplantation is the availability of donor material in sufficient quantities. This limitation may be overcome by the use of xenogeneic donors if long-term graft rejection can be prevented. The purpose of this study was to assess whether xenogeneic chromaffin cells immunologically isolated by semipermeable membranes could survive and continue to reduce pain when transplanted into the CNS. Isolated bovine chromaffin cells were encapsulated by semipermeable polymer membranes and implanted into the rat spinal subarachnoid space. Pain sensitivity was assessed at several intervals up to 3 months following implantation. Results indicated that encapsulated bovine chromaffin cell implants, but not empty control capsules, could repeatedly reduce pain sensitivity with nicotine stimulation for the duration of the study. This response was dose related, indicating that pharmacologic integrity of the transplanted chromaffin cells is retained. The analgesia induced by encapsulated chromaffin cell implants could be attenuated by the opiate antagonist naloxone and the alpha-adrenergic antagonist phentolamine, suggesting the involvement of both opioid peptides and catecholamines in mediating this response. In addition, in vitro neurochemical studies of recultured capsules revealed sustained release of Met-enkephalin and catecholamines from encapsulated cells 3 months following implantation into the spinal subarachnoid space.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7684773

  17. Guide to radiological accident considerations for siting and design of DOE nonreactor nuclear facilities

    SciTech Connect

    Elder, J.C.; Graf, J.M.; Dewart, J.M.; Buhl, T.E.; Wenzel, W.J.; Walker, L.J.; Stoker, A.K.

    1986-01-01

    This guide was prepared to provide the experienced safety analyst with accident analysis guidance in greater detail than is possible in Department of Energy (DOE) Orders. The guide addresses analysis of postulated serious accidents considered in the siting and selection of major design features of DOE nuclear facilities. Its scope has been limited to radiological accidents at nonreactor nuclear facilities. The analysis steps addressed in the guide lead to evaluation of radiological dose to exposed persons for comparison with siting guideline doses. Other possible consequences considered are environmental contamination, population dose, and public health effects. Choices of models and parameters leading to estimation of source terms, release fractions, reduction and removal factors, dispersion and dose factors are discussed. Although requirements for risk analysis have not been established, risk estimates are finding increased use in siting of major nuclear facilities, and are discussed in the guide. 3 figs., 9 tabs.

  18. 324 Building Baseline Radiological Characterization

    SciTech Connect

    R.J. Reeder, J.C. Cooper

    2010-06-24

    This report documents the analysis of radiological data collected as part of the characterization study performed in 1998. The study was performed to create a baseline of the radiological conditions in the 324 Building.

  19. Radiology of thoracic diseases

    SciTech Connect

    Swensen, S.J.; Pugatch, R.D.

    1989-01-01

    This book presents the essential clinical and radiologic findings of a wide variety of thoracic diseases. The authors include conventional, CT and MR images of each disease discussed. In addition, they present practical differential diagnostic considerations for most of the radiographic findings or patterns portrayed.

  20. Practical interventional radiology

    SciTech Connect

    Von Sonnenberg, E.; Mueller, P.R.

    1988-01-01

    This book describes techniques employed in interventional radiology with emphasis on imaging leading to intervention. Includes the entire array of procedures available to the radiologist, discussing the indications, materials, technique, results, and complications for each. Covers the chest, abdomen, bone, pediatric considerations, and nursing care.

  1. Radiological Defense Manual.

    ERIC Educational Resources Information Center

    Defense Civil Preparedness Agency (DOD), Washington, DC.

    Originally prepared for use as a student textbook in Radiological Defense (RADEF) courses, this manual provides the basic technical information necessary for an understanding of RADEF. It also briefly discusses the need for RADEF planning and expected postattack emergency operations. There are 14 chapters covering these major topics: introduction…

  2. Radiology of spinal curvature

    SciTech Connect

    De Smet, A.A.

    1985-01-01

    This book offers the only comprehensive, concise summary of both the clinical and radiologic features of thoracic and lumbar spine deformity. Emphasis is placed on idiopathic scoliosis, which represents 85% of all patients with scoliosis, but less common areas of secondary scoliosis, kyphosis and lordosis are also covered.

  3. PACS for GU radiology

    NASA Astrophysics Data System (ADS)

    Hayrapetian, Alek S.; Barbaric, Zoran L.; Weinberg, Wolfram S.; Chan, Kelby K.; Loloyan, Mansur; Taira, Ricky K.; Huang, H. K.

    1991-07-01

    The authors have developed a PACS module for genito-urinary radiology. This module is based on image acquisition subsystem, database and storage server/cluster controllers, communication networks, display workstation and local database, and dedicated digitizer and printer. The design guideline for this system is generality and flexibility. As such this module serves as a prototype for future PACS module designs.

  4. Radiologic Technology Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This guide presents the standard curriculum for technical institutes in Georgia. The curriculum addresses the minimum competencies for a radiologic technology program. The guide contains four major sections. The General Information section contains an introduction giving an overview and defining purpose and objectives; a program description,…

  5. Radiology Technician (AFSC 90370).

    ERIC Educational Resources Information Center

    Sobczak, James

    This five-volume student text is designed for use by Air Force personnel enrolled in a self-study extension course for radiology technicians. Covered in the individual volumes are radiographic fundamentals (x-ray production; primary beams; exposure devices; film, film holders, and darkrooms; control of film quality; and environmental safety);…

  6. Radiological dose assessments of atolls in the Northern Marshall Islands

    SciTech Connect

    Robison, W.L.

    1983-11-01

    Methods and models used to estimate the radiation doses to a returning population of the atolls in the Marshall Islands are presented. In this environment natural processes have acted on source-term radionuclides for nearly 30 years. The data bases developed for the models, and the results of the radiological dose analyses at the various atolls are described. The major radionuclides in order of their contribution to the total estimated doses were /sup 137/Cs, /sup 90/Sr, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 60/Co. Exposure pathways in order of their contribution to the estimated doses were: terrestrial food chain, external ..gamma.., marine food chain, inhalation, and cistern water and ground water. 56 references, 13 figures, 16 tables.

  7. Ethical problems in radiology: radiological consumerism.

    PubMed

    Magnavita, N; Bergamaschi, A

    2009-10-01

    One of the causes of the increasing request for radiological examinations occurring in all economically developed countries is the active role played by the patient-consumer. Consumerism places the radiologist in an ethical dilemma, between the principle of autonomy on the one hand and the ethical principles of beneficence, nonmaleficence and justice on the other. The choice made by radiologists in moral dilemmas is inspired by an adherence to moral principles, which in Italy and elsewhere refer to the Judaeo-Christian tradition or to neo-Darwinian relativism. Whatever the choice, the radiologist is bound to adhere to that choice and to provide the patient with all the relevant information regarding his or her state of health. PMID:19662338

  8. Radiologic technology educators and andragogy.

    PubMed

    Galbraith, M W; Simon-Galbraith, J A

    1984-01-01

    Radiologic technology educators are in constant contact with adult learners. However, the theoretical framework that radiologic educators use to guide their instruction may not be appropriate for adults. This article examines the assumptions of the standard instructional theory and the most modern approach to adult education-- andragogy . It also shows how these assumptions affect the adult learner in a radiologic education setting. PMID:6729091

  9. Poul Erik Andersen's radiological work on Osteochondrodysplasias and interventional radiology

    PubMed Central

    Andersen, Poul Erik

    2011-01-01

    Poul Erik Andersen is a Professor and Interventional Radiologist at the University of Southern Denmark, Odense and Odense University Hospital, Denmark. His innovative and expertise is primarily in vascular interventions where he has introduced and developed many procedures at Odense University Hospital. His significant experience and extensive scientific work has led to many posts in the Danish Society of Interventional Radiology, the European Society of Radiology and the Cardiovascular and Interventional Radiological Society of Europe, where he is a fellow and has passed the European Board of Interventional Radiology - The European qualification in Interventional Radiology. PMID:22022640

  10. Effect of changes in technical parameters in radiological safety

    NASA Astrophysics Data System (ADS)

    Avendaño, Ge; Fernandez, C.

    2007-11-01

    This work analyzes the generation of secondary radiation that affects the professionals of health during interventional X ray procedures in first level hospitals. The research objectives were, on the one hand, to quantify the amount of radiation and to compare it with norms in force with respect to magnitudes, and on the other hand to evaluate the elements of protection used. The measurements will help to improve the radiological safety, to assess the eventuality of risks and, in the last term, to the possibility of norms modification for the improvement of the protection, especially that of the personnel who daily make a certain amount of interventional procedures guided by radiation, like angiographic cine applications, using continuous or pulsed fluoroscopy. The motivation of the study is in the suspicion that present interventionism is made with a false sensation of safety, based only in the use of lead apron and protection elements incorporated in the equipment by the manufacturer, nevertheless not always the health personnel are conscious that an excessive proximity with the tube and the patient body becomes a risky source of secondary and scattered radiation. The obtained results allow us to demonstrate the existence of conditions of risk, even possible iatrogenic events, in particular when the procedures imply the use of certain techniques of radiographic exploration, thus reaching the conclusion that the radiographic methodology must be changed in order to rationalize so much?. In order to achieve this we propose modifications to the present norms and legislation referred to the radiological safety in Chile.

  11. Workshop on the source term for radionuclide migration from high-level waste or spent nuclear fuel under realistic repository conditions: proceedings

    SciTech Connect

    Hunter, T.O.; Muller, A.B.

    1985-07-01

    Sixteen papers were presented at the workshop. The fourteen full-length papers included in the proceedings were processed separately. Only abstracts were included for the following two papers: Data Requirements Based on Performance Assessment Analyses of Conceptual Waste Packages in Salt Repositories, and The Potential Effects of Radiation on the Source Term in a Salt Repository. (LM)

  12. Effect of different protein sources on satiation and short-term satiety when consumed as a starter

    PubMed Central

    2011-01-01

    Background Because the source of protein may play a role in its satiating effect, we investigated the effect of different proteins on satiation and short-term satiety. Methods Two randomized single-blind cross-over studies were completed. In the first study, we investigated the effect of a preload containing 20 g of casein, whey, pea protein, egg albumin or maltodextrin vs. water control on food intake 30 min later in 32 male volunteers (25 ± 4 yrs, BMI 24 ± 0.4 kg/m2). Subjective appetite was assessed using visual analogue scales at 10 min intervals after the preload. Capillary blood glucose was measured every 30 min during 2 hrs before and after the ad libitum meal. In the second study, we compared the effect of 20 g of casein, pea protein or whey vs. water control on satiation in 32 male volunteers (25 ± 0.6 yrs, BMI 24 ± 0.5 kg/m2). The preload was consumed as a starter during an ad libitum meal and food intake was measured. The preloads in both studies were in the form of a beverage. Results In the first study, food intake was significantly lower only after casein and pea protein compared to water control (P = 0.02; 0.04 respectively). Caloric compensation was 110, 103, 62, 56 and 51% after casein, pea protein, whey, albumin and maltodextrin, respectively. Feelings of satiety were significantly higher after casein and pea protein compared to other preloads (P < 0.05). Blood glucose response to the meal was significantly lower when whey protein was consumed as a preload compared to other groups (P < 0.001). In the second study, results showed no difference between preloads on ad libitum intake. Total intake was significantly higher after caloric preloads compared to water control (P < 0.05). Conclusion Casein and pea protein showed a stronger effect on food intake compared to whey when consumed as a preload. However, consuming the protein preload as a starter of a meal decreased its impact on food intake as opposed to consuming it 30 min before the meal

  13. Source term estimation and the isotopic ratio of radioactive material released from the WIPP repository in New Mexico, USA.

    PubMed

    Thakur, P

    2016-01-01

    After almost 15 years of operations, the Waste Isolation Pilot Plant (WIPP) had one of its waste drums breach underground as a result of a runaway chemical reaction in the waste it contained. This incident occurred on February 14, 2014. Moderate levels of radioactivity were released into the underground air. A small portion of the contaminated underground air also escaped to the surface through the ventilation system and was detected approximately 1 km away from the facility. According to the source term estimation, the actual amount of radioactivity released from the WIPP site was less than 1.5 mCi. The highest activity detected on the surface was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately 1 km northwest of the WIPP facility. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. Air monitoring across the WIPP site intensified following the first reports of radiation detection underground to determine the extent of impact to WIPP personnel, the public, and the environment. In this paper, the early stage monitoring data collected by an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC) and an oversight monitoring program conducted by the WIPP's management and operating contractor, the Nuclear Waste Partnership (NWP) LLC were utilized to estimate the actual amount of radioactivity released from the WIPP underground. The Am and Pu isotope ratios were measured and used to support the hypothesis that the release came from one drum identified as having breached that represents a specific waste stream with this radionuclide ratio in its inventory. This failed drum underwent a heat and gas producing reaction that overpowered its vent and

  14. GUIDANCE MANUAL FOR SOURCE WATER MONITORING UNDER THE LONG-TERM 2 ENHANCED SURFACE WATER TREATMENT RULE (LT2ESWTR)

    EPA Science Inventory

    The manual explains the source water monitoring requirements of LT2ESWTR; provides guidance on how to collect samples for Cryptosporidium and E. coli and on how to establish and manage a Cryptosporidium laboratory contract; and explains how to use and interpret source water monit...

  15. INEEL Subregional Conceptual Model Report Volume 3: Summary of Existing Knowledge of Natural and Anthropogenic Influences on the Release of Contaminants to the Subsurface Environment from Waste Source Terms at the INEEL

    SciTech Connect

    Paul L. Wichlacz

    2003-09-01

    This source-term summary document is intended to describe the current understanding of contaminant source terms and the conceptual model for potential source-term release to the environment at the Idaho National Engineering and Environmental Laboratory (INEEL), as presented in published INEEL reports. The document presents a generalized conceptual model of the sources of contamination and describes the general categories of source terms, primary waste forms, and factors that affect the release of contaminants from the waste form into the vadose zone and Snake River Plain Aquifer. Where the information has previously been published and is readily available, summaries of the inventory of contaminants are also included. Uncertainties that affect the estimation of the source term release are also discussed where they have been identified by the Source Term Technical Advisory Group. Areas in which additional information are needed (i.e., research needs) are also identified.

  16. A systematic search for long-term variability in a large sample of X-ray sources

    NASA Technical Reports Server (NTRS)

    Maccacaro, Tommaso; Garilli, Bianca; Mereghetti, Sandro

    1987-01-01

    A method which uses the correct measurement error distribution (Poisson) and which naturally takes into account detections as well as upper limits has been developed to search for flux variability in X-ray sources. The method is applied to 256 sources observed at least twice with the Einstein Observatory Imaging Proportional Counter. These sources have, in the very large majority of cases, an X-ray flux in the range 1 x 10 to the -13th to 6 x 10 to the -12th erg/sq cm/s (0.2-3.5 keV). Thirty-one sources show flux variations with amplitude ranging from about 20 percent to a factor of 6. Flux variations of small amplitude seem to be fairly common, but can be detected only in bright sources or in sources observed with very long exposures. Variations of a factor of 2 or more are seen in about 15 percent of the sources for which variations of such an amplitude are detectable.

  17. PM2.5 source apportionment: reconciling receptor models for U.S. nonurban and urban long-term networks.

    PubMed

    Chen, L W Antony; Watson, John G; Chow, Judith C; DuBois, Dave W; Herschberger, Lisa

    2011-11-01

    Chemical mass balance (CMB) and trajectory receptor models were applied to speciated particulate matter with aerodynamic diameter < or =2.5 microm (PM2.5) measurements from Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network across the state of Minnesota as part of the Minnesota PM2.5 Source Apportionment Study (MPSAS). CMB equations were solved by the Unmix, positive matrix factorization (PMF), and effective variance (EV) methods, giving collective source contribution and uncertainty estimates. Geological source profiles developed from local dust materials were either incorporated into the EV-CMB model or used to verify factors derived from Unmix and PMF. Common sources include soil dust, calcium (Ca)-rich dust, diesel and gasoline vehicle exhausts, biomass burning, secondary sulfate, and secondary nitrate. Secondary sulfate and nitrate aerosols dominate PM2.5 mass (50-69%). Mobile sources outweigh area sources at urban sites, and vice versa at rural sites due to traffic emissions. Gasoline and diesel contributions can be separated using data from the STN, despite significant uncertainties. Major differences between MPSAS and earlier studies on similar environments appear to be the type and magnitude of stationary sources, but these sources are generally minor (<7%) in this and other studies. Ensemble back-trajectory analysis shows that the lower Midwestern states are the predominant source region for secondary ammoniated sulfate in Minnesota. It also suggests substantial contributions of biomass burning and soil dust from out-of-state on occasions, although a quantitative separation of local and regional contributions was not achieved in the current study. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for a summary of input data, Unmix and PMF

  18. Data mining in radiology

    PubMed Central

    Kharat, Amit T; Singh, Amarjit; Kulkarni, Vilas M; Shah, Digish

    2014-01-01

    Data mining facilitates the study of radiology data in various dimensions. It converts large patient image and text datasets into useful information that helps in improving patient care and provides informative reports. Data mining technology analyzes data within the Radiology Information System and Hospital Information System using specialized software which assesses relationships and agreement in available information. By using similar data analysis tools, radiologists can make informed decisions and predict the future outcome of a particular imaging finding. Data, information and knowledge are the components of data mining. Classes, Clusters, Associations, Sequential patterns, Classification, Prediction and Decision tree are the various types of data mining. Data mining has the potential to make delivery of health care affordable and ensure that the best imaging practices are followed. It is a tool for academic research. Data mining is considered to be ethically neutral, however concerns regarding privacy and legality exists which need to be addressed to ensure success of data mining. PMID:25024513

  19. Data mining in radiology.

    PubMed

    Kharat, Amit T; Singh, Amarjit; Kulkarni, Vilas M; Shah, Digish

    2014-04-01

    Data mining facilitates the study of radiology data in various dimensions. It converts large patient image and text datasets into useful information that helps in improving patient care and provides informative reports. Data mining technology analyzes data within the Radiology Information System and Hospital Information System using specialized software which assesses relationships and agreement in available information. By using similar data analysis tools, radiologists can make informed decisions and predict the future outcome of a particular imaging finding. Data, information and knowledge are the components of data mining. Classes, Clusters, Associations, Sequential patterns, Classification, Prediction and Decision tree are the various types of data mining. Data mining has the potential to make delivery of health care affordable and ensure that the best imaging practices are followed. It is a tool for academic research. Data mining is considered to be ethically neutral, however concerns regarding privacy and legality exists which need to be addressed to ensure success of data mining. PMID:25024513

  20. Conjoined twins: Radiological experience.

    PubMed

    Watson, Sarah G; McHugh, Kieran

    2015-10-01

    Imaging plays a key role in the management of conjoined twins. Pre-operative multi-modality studies are vital to assess operability and to aid surgical planning. Technical advances in imaging such as high-resolution isovolumetric magnetic resonance imaging (MRI) techniques and three-dimensional modeling now result in extremely accurate anatomical information. Varied information from a comprehensive radiological work-up enables the surgeons to plan the safest possible operative procedure, helps the anesthetic team before and during surgery, and guides the intensive care team in the post-operative phase. This article will review the radiological techniques used in our institution, highlighting potential pitfalls with the various imaging modalities. PMID:26382258

  1. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of atmospheric dispersion model with improved deposition scheme and oceanic dispersion model

    NASA Astrophysics Data System (ADS)

    Katata, G.; Chino, M.; Kobayashi, T.; Terada, H.; Ota, M.; Nagai, H.; Kajino, M.; Draxler, R.; Hort, M. C.; Malo, A.; Torii, T.; Sanada, Y.

    2014-06-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Dai-ichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate a detailed time trend of atmospheric releases during the accident by combining environmental monitoring data with atmospheric model simulations from WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information), and simulations from the oceanic dispersion model SEA-GEARN-FDM, both developed by the authors. A sophisticated deposition scheme, which deals with dry and fogwater depositions, cloud condensation nuclei (CCN) activation and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I2 and CH3I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The fallout to the ocean surface calculated by WSPEEDI-II was used as input data for the SEA-GEARN-FDM calculations. Reverse and inverse source-term estimation methods based on coupling the simulations from both models was adopted using air dose rates and concentrations, and sea surface concentrations. The results revealed that the major releases of radionuclides due to FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, the morning of 13 March after the venting event at Unit 3, midnight of 14 March when the SRV (Safely Relief Valve) at Unit 2 was opened three times, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of

  2. Disabling Radiological Dispersal Terror

    SciTech Connect

    Hart, M

    2002-11-08

    Terror resulting from the use of a radiological dispersal device (RDD) relies upon an individual's lack of knowledge and understanding regarding its significance. Disabling this terror will depend upon realistic reviews of the current conservative radiation protection regulatory standards. It will also depend upon individuals being able to make their own informed decisions merging perceived risks with reality. Preparation in these areas will reduce the effectiveness of the RDD and may even reduce the possibility of its use.

  3. Initial experiences in radiology e-learning.

    PubMed

    Sparacia, Gianvincenzo; Cannizzaro, Floreana; D'Alessandro, Donna M; D'Alessandro, Michael P; Caruso, Giuseppe; Lagalla, Roberto

    2007-01-01

    The use of two different educator-centric learning management systems (LMSs), Moodle and Manila, for radiology e-learning was formatively evaluated and the implications of the future use of LMSs in radiology education were explored. NeuroRAD, a neuroradiologic digital library and learning community, is implemented with Moodle, one of the most popular open-source educator-centric LMSs. Pediatric-Education.org, a pediatric digital library and learning community, is implemented with Manila, a commercial educator-centric LMS. Quantitative and qualitative analyses of these LMSs were performed with World Wide Web server log file statistical programs and user-submitted comment forms. In 2005, NeuroRAD was used by 9959 visitors, who read 98,495 pages of information, whereas PediatricEducation .org was used by 91,000 visitors, who read 186,000 pages of information. Visitors represented a wide spectrum of medical learners and used the sites to answer clinical questions; to prepare for lectures, conferences, and informal teaching sessions; and to stay up-to-date and prepare for examinations. Early results indicate that radiology learning communities can be implemented with educator-centric LMSs relatively easily and at low cost by radiologists with minimal computer expertise, and can find receptive and appreciative audiences. Online radiology learning communities could play a significant role in providing education to radiologists the world over throughout their careers. PMID:17374871

  4. Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of an atmospheric dispersion model with an improved deposition scheme and oceanic dispersion model

    NASA Astrophysics Data System (ADS)

    Katata, G.; Chino, M.; Kobayashi, T.; Terada, H.; Ota, M.; Nagai, H.; Kajino, M.; Draxler, R.; Hort, M. C.; Malo, A.; Torii, T.; Sanada, Y.

    2015-01-01

    Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I2 and CH3I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of cumulative

  5. Examining Long-Term Trends in Mobile Source Related Pollutants through Analysis of Emissions, Observations and Model Simulations

    EPA Science Inventory

    Anthropogenic emissions from a variety of sectors including mobile sources have decreased substantially over the past decades despite continued growth in population and economic activity. In this study, we analyze 1990-2010 trends in emission inventories, ambient observations and...

  6. Southern states radiological emergency response laws and regulations

    SciTech Connect

    Not Available

    1989-02-01

    The radiological emergency response laws and regulations of the Southern States Energy Compact member states are in some cases disparate. Several states have very specific laws on radiological emergency response while in others, the statutory law mentions only emergency response to ``natural disasters.`` Some states have adopted extensive regulations on the topic; others have none. For this reason, any general overview must necessarily discuss laws and regulations in general terms.

  7. Estimate of the radiation source term for 18F production via thick H218O targets bombarded with 18 MeV protons

    NASA Astrophysics Data System (ADS)

    Cruzate, Juan Ángel

    2015-12-01

    The positron-emitting radionuclide most important from the point of view of radiation protection is 18F. This isotope is usually produced by bombarding 18O-enriched water with protons. Currently there are few experimental data on the radiation source term generated during these reactions. In addition, presently there is no theoretical estimates of this source term, for use in radiation protection, validated by experimental data. Up till now this term is calculated by using nuclear interactions' simulation codes, such as ALICE91. An estimate of the energy spectra for neutrons and photons, induced by 18 MeV protons on H218O target, have been calculated by using MCNPX code with cross sections from release 0 of ENDF/B VII library for all materials except 18O, for which TENDL-2012 library was used. This estimate was validated against a recent experiment carried out at the Japan Atomic Energy Agency (JAEA). The calculated spectra have generally well reproduced experiments. The results show that the calculated radiation source term may be used to estimate the neutron activation of the accelerator components and the cyclotron building, to calculate the cyclotron shielding, and to carry out radiation protection evaluations in general, for the case of cyclotrons producing 18F by means of the 18O(p,n)18F nuclear reactions, for proton energies up to 18 MeV.

  8. Lessons Learned from Characterization, Performance Assessment, and EPA Regulatory Review of the 1996 Actinide Source Term for the Waste Isolation Pilot Plant

    SciTech Connect

    Larson, K.W.; Moore, R.C.; Nowak, E.J.; Papenguth, H.W.; Jow, H.

    1999-03-22

    The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy (DOE) facility for the permanent disposal of transuranic waste from defense activities. In 1996, the DOE submitted the Title 40 CFR Part 191 Compliance Certification Application for the Waste Isolation Pilot Plant (CCA) to the US Environmental Protection Agency (EPA). The CCA included a probabilistic performance assessment (PA) conducted by Sandia National Laboratories to establish compliance with the quantitative release limits defined in 40 CFR 191.13. An experimental program to collect data relevant to the actinide source term began around 1989, which eventually supported the 1996 CCA PA actinide source term model. The actinide source term provided an estimate of mobile dissolved and colloidal Pu, Am, U, Th, and Np concentrations in their stable oxidation states, and accounted for effects of uncertainty in the chemistry of brines in waste disposal areas. The experimental program and the actinide source term included in the CCA PA underwent EPA review lasting more than 1 year. Experiments were initially conducted to develop data relevant to the wide range of potential future conditions in waste disposal areas. Interim, preliminary performance assessments and actinide source term models provided insight allowing refinement of experiments and models. Expert peer review provided additional feedback and confidence in the evolving experimental program. By 1995, the chemical database and PA predictions of WIPP performance were considered reliable enough to support the decision to add an MgO backfill to waste rooms to control chemical conditions and reduce uncertainty in actinide concentrations, especially for Pu and Am. Important lessons learned through the characterization, PA modeling, and regulatory review of the actinide source term are (1) experimental characterization and PA should evolve together, with neither activity completely dominating the other, (2) the understanding of physical processes

  9. Towards interpreting nitrate-δ15N records in ice cores in terms of nitrogen oxide sources

    NASA Astrophysics Data System (ADS)

    Hastings, M. G.; Buffen, A. M.

    2011-12-01

    The isotopic composition of nitrate preserved in ice cores offers unique potential for reconstructing past contributions of nitrogen oxides (NOx = NO and NO2) to the atmosphere. Sources of NOx imprint a nitrogen stable isotopic (δ15N) signature, which can be conserved during subsequent oxidation to form nitrate. Major sources of NOx include fossil fuels combustion, biomass burning, microbial processes in soils, and lightning, and thus a quantitative tracer of emissions would help detail connections between the atmosphere, the biosphere, and climate. Unfortunately, the δ15N signatures of most NOx sources are not yet well enough constrained to allow for quantitative partitioning, though new methodology for directly collecting NOx for isotopic analysis is promising (Fibiger and Hastings, A43D-0265, AGU 2010). Still, a growing network of ice core δ15N records may offer insight into source signatures, as different sources are important to different regions of the world. For example, a 300-year ice core record of nitrate-δ15N from Summit, Greenland shows a clear and significant 12% (vs. N2) decrease since the Preindustrial that reflects emissions from fossil fuel combustion and/or soils related to changing agricultural practices in North America and Europe. Over the same time period, Antarctic ice cores show no such trend in δ15N. This would be consistent with previous work suggesting that biomass burning and/or stratospheric intrusion of NOx produced from N2O oxidation are dominant sources for nitrate formation at high southern latitudes. In comparison to the polar records, nitrate in tropical ice cores should represent more significant inputs from lightning, microbial processes in soils, and biomass burning. This may be reflected in new results from a high-elevation site in the Peruvian Andes that shows strong seasonal δ15N cycles of up to 15% (vs. N2). We compare and contrast these records in an effort to evaluate the contribution of NOx sources to nitrate over

  10. Analyzing the contribution of climate change to long-term variations in sediment nitrogen sources for reservoirs/lakes.

    PubMed

    Xia, Xinghui; Wu, Qiong; Zhu, Baotong; Zhao, Pujun; Zhang, Shangwei; Yang, Lingyan

    2015-08-01

    We applied a mixing model based on stable isotopic δ(13)C, δ(15)N, and C:N ratios to estimate the contributions of multiple sources to sediment nitrogen. We also developed a conceptual model describing and analyzing the impacts of climate change on nitrogen enrichment. These two models were conducted in Miyun Reservoir to analyze the contribution of climate change to the variations in sediment nitrogen sources based on two (210)Pb and (137)Cs dated sediment cores. The results showed that during the past 50years, average contributions of soil and fertilizer, submerged macrophytes, N2-fixing phytoplankton, and non-N2-fixing phytoplankton were 40.7%, 40.3%, 11.8%, and 7.2%, respectively. In addition, total nitrogen (TN) contents in sediment showed significant increasing trends from 1960 to 2010, and sediment nitrogen of both submerged macrophytes and phytoplankton sources exhibited significant increasing trends during the past 50years. In contrast, soil and fertilizer sources showed a significant decreasing trend from 1990 to 2010. According to the changing trend of N2-fixing phytoplankton, changes of temperature and sunshine duration accounted for at least 43% of the trend in the sediment nitrogen enrichment over the past 50years. Regression analysis of the climatic factors on nitrogen sources showed that the contributions of precipitation, temperature, and sunshine duration to the variations in sediment nitrogen sources ranged from 18.5% to 60.3%. The study demonstrates that the mixing model provides a robust method for calculating the contribution of multiple nitrogen sources in sediment, and this study also suggests that N2-fixing phytoplankton could be regarded as an important response factor for assessing the impacts of climate change on nitrogen enrichment. PMID:25862992

  11. An inverse modeling method to assess the source term of the Fukushima nuclear power plant accident using gamma dose rate observations

    NASA Astrophysics Data System (ADS)

    Saunier, O.; Mathieu, A.; Didier, D.; Tombette, M.; Quélo, D.; Winiarek, V.; Bocquet, M.

    2013-06-01

    The Chernobyl nuclear accident and more recently the Fukushima accident highlighted that the largest source of error on consequences assessment is the source term including the time evolution of the release rate and its distribution between radioisotopes. Inverse modeling methods, which combine environmental measurements and atmospheric dispersion models, have proven efficient in assessing source term due to an accidental situation (Gudiksen, 1989; Krysta and Bocquet, 2007; Stohl et al., 2012a; Winiarek et al., 2012). Most existing approaches are designed to use air sampling measurements (Winiarek et al., 2012) and some of them also use deposition measurements (Stohl et al., 2012a; Winiarek et al., 2013) but none of them uses dose rate measurements. However, it is the most widespread measurement system, and in the event of a nuclear accident, these data constitute the main source of measurements of the plume and radioactive fallout during releases. This paper proposes a method to use dose rate measurements as part of an inverse modeling approach to assess source terms. The method is proven efficient and reliable when applied to the accident at the Fukushima Daiichi nuclear power plant (FD-NPP). The emissions for the eight main isotopes 133Xe, 134Cs, 136Cs, 137Cs, 137mBa, 131I, 132I and 132Te have been assessed. Accordingly, 103 PBq of 131I, 35.5 PBq of 132I, 15.5 PBq of 137Cs and 12 100 PBq of noble gases were released. The events at FD-NPP (such as venting, explosions, etc.) known to have caused atmospheric releases are well identified in the retrieved source term. The estimated source term is validated by comparing simulations of atmospheric dispersion and deposition with environmental observations. The result is that the model-measurement agreement for all of the monitoring locations is correct for 80% of simulated dose rates that are within a factor of 2 of the observed values. Changes in dose rates over time have been overall properly reconstructed, especially

  12. Long-Term Variability and Transient Behavior of some Galactic Hard X-Ray Sources as Observed with BATSE

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.

    1998-01-01

    The Burst and Transient Source Experiment (BATSE) experiment on the Compton Observatory has been providing continuous, all-sky monitoring of the hard X-ray sky for over seven years. A wide variety of transient and high-variability phenomena are observed for about sixty Galactic neutron star and black hole systems. A daily sensitivity level of approximately 75 mCrab is attained for sources observed by Earth occultation in un-crowded regions and approximately 20 mCrab for pulsars with known periods. This talk will qualitatively describe the types of variability that are observed from some of the brighter sources, including their duty-cycle and the various time-scales observed. Implications for the INTEGRAL mission will be discussed.

  13. Development of a Google-based search engine for data mining radiology reports.

    PubMed

    Erinjeri, Joseph P; Picus, Daniel; Prior, Fred W; Rubin, David A; Koppel, Paul

    2009-08-01

    The aim of this study is to develop a secure, Google-based data-mining tool for radiology reports using free and open source technologies and to explore its use within an academic radiology department. A Health Insurance Portability and Accountability Act (HIPAA)-compliant data repository, search engine and user interface were created to facilitate treatment, operations, and reviews preparatory to research. The Institutional Review Board waived review of the project, and informed consent was not required. Comprising 7.9 GB of disk space, 2.9 million text reports were downloaded from our radiology information system to a fileserver. Extensible markup language (XML) representations of the reports were indexed using Google Desktop Enterprise search engine software. A hypertext markup language (HTML) form allowed users to submit queries to Google Desktop, and Google's XML response was interpreted by a practical extraction and report language (PERL) script, presenting ranked results in a web browser window. The query, reason for search, results, and documents visited were logged to maintain HIPAA compliance. Indexing averaged approximately 25,000 reports per hour. Keyword search of a common term like "pneumothorax" yielded the first ten most relevant results of 705,550 total results in 1.36 s. Keyword search of a rare term like "hemangioendothelioma" yielded the first ten most relevant results of 167 total results in 0.23 s; retrieval of all 167 results took 0.26 s. Data mining tools for radiology reports will improve the productivity of academic radiologists in clinical, educational, research, and administrative tasks. By leveraging existing knowledge of Google's interface, radiologists can quickly perform useful searches. PMID:18392657

  14. Radiological considerations of phosphogypsum utilization in agriculture

    SciTech Connect

    Lindeken, C.L.

    1980-10-31

    The radiological concerns associated with phosphogypsum utilization in agriculture have been placed in perspective by considering the consequences of a hypothetical case involving heavy long term applications of phosphogypsum. In California, such a schedule might consist of an initial gypsum application of 10 tons/acre followed by alternate year applications of 5 tons/acre. If the radium content of the gypsum were 15 pCi/g and the till depth 6 inches, this schedule could be maintained for more than 100 years before the radium buildup in the soil would reach a proposed federal concentration limit of 5 pCi/g. An agricultural worker spending 40 h a week in a field containing 5 pCi/g of radium would be exposed to terrestrial radiation of about 7 ..mu..R/h above background. This exposure would result in an annual radiation dose of about 15 mrem, which is 3% of the recommended limit for an individual working in an uncontrolled area. Five pCi/g of radium in the soil could generate airborne radon daughter concentrations exceeding the concentration limit proposed for residential exposure. However, as residential exposure limits are predicated on 75% of continuous occupancy, these limits should not be applied to agricultural workers because of the seasonal nature of their work. Radium uptake by food crops grown in the hypothetical soil would result in a 50 year integrated dose to the bone surface of 1.4 rem. This dose is conservatively based on the assumption that an adult's total vegetable diet comes from this source and that consumption was continuous during the 50 year period.

  15. Soil carbon and nitrogen sequestration as affected by long-term tillage, cropping system, and nitrogen fertilizer sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poultry litter application in no-tilled intensive cropping system could increase soil C and N sequestration compared with conventional management practices. We evaluated the 10-year effects of tillage, cropping systems, and N sources on crop residue (stems + leaves) production and soil organic C (SO...

  16. Multilingual retrieval of radiology images.

    PubMed

    Kahn, Charles E

    2009-01-01

    The multilingual search engine ARRS GoldMiner Global was created to facilitate broad international access to a richly indexed collection of more than 200,000 radiologic images. Images are indexed according to key-words and medical concepts that appear in the unstructured text of their English-language image captions. GoldMiner Global exploits the Unicode standard, which allows the accurate representation of characters and ideographs from virtually any language and which supports both left-to-right and right-to-left text directions. The user interface supports queries in Arabic, Chinese, French, German, Italian, Japanese, Korean, Portuguese, Russian, or Spanish. GoldMiner Global incorporates an interface to the United States National Library of Medicine that translates queries into English-language Medical Subject Headings (MeSH) terms. The translated MeSH terms are then used to search the image index and retrieve relevant images. Explanatory text, pull-down menu choices, and navigational guides are displayed in the selected language; search results are displayed in English. GoldMiner Global is freely available on the World Wide Web. PMID:19019997

  17. Emerging strategic themes for guiding change in academic radiology departments.

    PubMed

    Chan, Stephen; Gunderman, Richard B

    2005-08-01

    Academic radiologists are faced with increasing demands on their time and energy, particularly in the clinical arena, where larger examination volumes and higher service expectations are the norm for most medical centers. These demands are intensified by the continuing shortage of academic radiologists. If academic radiology departments continue to devote most of their resources to the clinical mission at the expense of research and educational missions, then there are potentially serious adverse consequences for long-term viability of the profession of radiology. This dilemma represents a critical strategic problem, not just for academic radiology but also for the entire profession of radiology. In this article, the success and growth of academic radiology during the 20th century are framed as the result of the dogged pursuit of certain key strategic themes. With the concept of paradigm shift, introduced by Kuhn, several new strategic themes are identified that are just emerging from changes in work practices, organizational structure, and mind-sets in radiology departments at academic medical centers. One benefit of this approach is that it facilitates the ability of radiologists to articulate and focus on those strategic themes that will help academic radiology departments to adapt more rapidly and successfully to environmental changes during the 21st century. PMID:15972339

  18. Renewal of radiological equipment.

    PubMed

    2014-10-01

    In this century, medical imaging is at the heart of medical practice. Besides providing fast and accurate diagnosis, advances in radiology equipment offer new and previously non-existing options for treatment guidance with quite low morbidity, resulting in the improvement of health outcomes and quality of life for the patients. Although rapid technological development created new medical imaging modalities and methods, the same progress speed resulted in accelerated technical and functional obsolescence of the same medical imaging equipment, consequently creating a need for renewal. Older equipment has a high risk of failures and breakdowns, which might cause delays in diagnosis and treatment of the patient, and safety problems both for the patient and the medical staff. The European Society of Radiology is promoting the use of up-to-date equipment, especially in the context of the EuroSafe Imaging Campaign, as the use of up-to-date equipment will improve quality and safety in medical imaging. Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or renewal. This plan should look forward a minimum of 5 years, with annual updates. Teaching points • Radiological equipment has a definite life cycle span, resulting in unavoidable breakdown and decrease or loss of image quality which renders equipment useless after a certain time period.• Equipment older than 10 years is no longer state-of-the art equipment and replacement is essential. Operating costs of older equipment will be high when compared with new equipment, and sometimes maintenance will be impossible if no spare parts are available.• Older equipment has a high risk of failure and breakdown, causing delays in diagnosis and treatment of the patient and safety problems both for the patient and the medical staff.• Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or replacement. This plan should look forward a

  19. Source Term Estimation of Radioxenon Released from the Fukushima Dai-ichi Nuclear Reactors Using Measured Air Concentrations and Atmospheric Transport Modeling

    SciTech Connect

    Eslinger, Paul W.; Biegalski, S.; Bowyer, Ted W.; Cooper, Matthew W.; Haas, Derek A.; Hayes, James C.; Hoffman, Ian; Korpach, E.; Yi, Jing; Miley, Harry S.; Rishel, Jeremy P.; Ungar, R. Kurt; White, Brian; Woods, Vincent T.

    2014-01-01

    Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout from the Fukushima Daiichi nuclear accident in March 2011. Atmospheric transport modeling (ATM) of plumes of noble gases and particulates were performed soon after the accident to determine plausible detection locations of any radioactive releases to the atmosphere. We combine sampling data from multiple International Modeling System (IMS) locations in a new way to estimate the magnitude and time sequence of the releases. Dilution factors from the modeled plume at five different detection locations were combined with 57 atmospheric concentration measurements of 133-Xe taken from March 18 to March 23 to estimate the source term. This approach estimates that 59% of the 1.24×1019 Bq of 133-Xe present in the reactors at the time of the earthquake was released to the atmosphere over a three day period. Source term estimates from combinations of detection sites have lower spread than estimates based on measurements at single detection sites. Sensitivity cases based on data from four or more detection locations bound the source term between 35% and 255% of available xenon inventory.

  20. Radiological Toolbox User's Manual

    SciTech Connect

    Eckerman, KF

    2004-07-01

    A toolbox of radiological data has been assembled to provide users access to the physical, chemical, anatomical, physiological and mathematical data relevant to the radiation protection of workers and member of the public. The software runs on a PC and provides users, through a single graphical interface, quick access to contemporary data and the means to extract these data for further computations and analysis. The numerical data, for the most part, are stored within databases in SI units. However, the user can display and extract values using non-SI units. This is the first release of the toolbox which was developed for the U.S. Nuclear Regulatory Commission.

  1. Small bowel radiology

    SciTech Connect

    Antes, G.; Eggemann, F.

    1987-01-01

    This book deals mainly with technique, experiences and results of the biphasic small bowel enema (enteroclysis) with barium and methyl cellulose. The method allows the evaluation of both morphology and function of the small bowel. The introduction describes the examination technique, basic patterns, interpretation and indications, while the atlas shows a broad spectrum of small bowel diseases (Crohn's disease, other inflammatory diseases, tumors, motility disorders, obstructions and malformations). The possibilities of small bowel radiology are demonstrated with reference to clinical findings and differential diagnoses.

  2. Characterization of radiological emergencies

    SciTech Connect

    Chester, C.V.

    1985-01-01

    Several severe radiological emergencies were reviewed to determine the likely range of conditions which must be coped with by a mobile teleoperator designed for emergencies. The events reviewed included accidents at TMI (1978), SL-1 (1961), Y-12 (1958), Bethesda (1982), Chalk River (1952 and 1958), Lucens (1969). The important conditions were: radiation fields over 10,000 R/h, severe contamination, possible critical excursion, possible inert atmosphere, temperatures from 50/sup 0/C to -20/sup 0/C, 100% relative humidity, 60-cm-high obstacles, stairs, airlocks, darkness, and lack of electric power.

  3. Smart Radiological Dosimeter

    SciTech Connect

    Kosslow, William J.; Bandzuch, Gregory S.

    2004-07-20

    A radiation dosimeter providing an indication of the dose of radiation to which the radiation sensor has been exposed. The dosimeter contains features enabling the monitoring and evaluating of radiological risks so that a user can concentrate on the task at hand. The dosimeter provides an audible alarm indication that a predetermined time period has elapsed, an audible alarm indication reminding the user to check the dosimeter indication periodically, an audible alarm indicating that a predetermined accumulated dose has been prematurely reached, and an audible alarm indication prior or to reaching the 3/4 scale point.

  4. Measuring radiology's value in time saved.

    PubMed

    Lee, Christoph I; Enzmann, Dieter R

    2012-10-01

    Because radiology has historically not measured its added value to patient care and thus not communicated it in easily understood terms to all stakeholders, the specialty must correct this to prepare for the eventual transition from the current fee-for-service payment schedule to new value-based reimbursement systems. Given the increasing risk for marginalization, radiologists need to engage clinicians and managers to map the processes and associated costs of episodes of patient care to identify areas for providing and improving integrated diagnostic information and to measure the value thereof. In such time-driven, activity-based costing practices, radiologists should highlight how proper investments in the information generated by imaging and how radiologists' associated consultative and coordination of services can save greater resources downstream, especially in the nonrenewable resource of physician time, an increasingly scarce health care resource. Using physician time in the most efficient way will be a key element for decreasing health care costs at the aggregate level. Therefore, expressing radiology's contribution in terms of downstream physician time saved is a metric that can be easily understood by all stakeholders. In a conceptual framework centered on value, the specialty of radiology must focus more on its most important product, actionable information, rather than on imaging technologies themselves. Information, unlike imaging technologies, does not depreciate with time but rather increases in value the more it is used. PMID:23025865

  5. Annual Rates on Seismogenic Italian Sources with Models of Long-Term Predictability for the Time-Dependent Seismic Hazard Assessment In Italy

    NASA Astrophysics Data System (ADS)

    Murru, Maura; Falcone, Giuseppe; Console, Rodolfo

    2016-04-01

    The present study is carried out in the framework of the Center for Seismic Hazard (CPS) INGV, under the agreement signed in 2015 with the Department of Civil Protection for developing a new model of seismic hazard of the country that can update the current reference (MPS04-S1; zonesismiche.mi.ingv.it and esse1.mi.ingv.it) released between 2004 and 2006. In this initiative, we participate with the Long-Term Stress Transfer (LTST) Model to provide the annual occurrence rate of a seismic event on the entire Italian territory, from a Mw4.5 minimum magnitude, considering bins of 0.1 magnitude units on geographical cells of 0.1° x 0.1°. Our methodology is based on the fusion of a statistical time-dependent renewal model (Brownian Passage Time, BPT, Matthews at al., 2002) with a physical model which considers the permanent effect in terms of stress that undergoes a seismogenic source in result of the earthquakes that occur on surrounding sources. For each considered catalog (historical, instrumental and individual seismogenic sources) we determined a distinct rate value for each cell of 0.1° x 0.1° for the next 50 yrs. If the cell falls within one of the sources in question, we adopted the respective value of rate, which is referred only to the magnitude of the event characteristic. This value of rate is divided by the number of grid cells that fall on the horizontal projection of the source. If instead the cells fall outside of any seismic source we considered the average value of the rate obtained from the historical and the instrumental catalog, using the method of Frankel (1995). The annual occurrence rate was computed for any of the three considered distributions (Poisson, BPT and BPT with inclusion of stress transfer).

  6. Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube

    SciTech Connect

    Bucholz, J.A.

    2000-07-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source.

  7. Analytical and semianalytical solutions to the kinetic equation with Coulomb collision term and a monoenergetic source function

    SciTech Connect

    Goncharov, P. R.; Kuteev, B. V.; Ozaki, T.; Sudo, S.

    2010-11-15

    Analytical and semianalytical solutions have been obtained using a practical dimensionless form of Boltzmann kinetic equation assuming spatial homogeneity, azimuthal symmetry, and Maxwellian distributions of target plasma species. In contrast with formerly considered simplified equations with truncated collision terms, the exact Landau-Boltzmann collision operator is used, which conserves the number of particles, nullifies the collision term at statistical equilibrium, and describes the Maxwellization process naturally observed in correct solutions. A comparison with previous stationary and time-dependent analytical solutions is given. The new semianalytical results can be used in numerical modeling, for verification of solutions in more complex models, and in experimental data analysis, especially concerning nuclear processes and advanced localized, angle-resolved suprathermal particle diagnostics.

  8. Patient-centered Radiology.

    PubMed

    Itri, Jason N

    2015-10-01

    Patient-centered care (ie, care organized around the patient) is a model in which health care providers partner with patients and families to identify and satisfy patients' needs and preferences. In this model, providers respect patients' values and preferences, address their emotional and social needs, and involve them and their families in decision making. Radiologists have traditionally been characterized as "doctor-to-doctor" consultants who are distanced from patients and work within a culture that does not value patient centeredness. As medicine becomes more patient driven and the trajectory of health care is toward increasing patient self-reliance, radiologists must change the perception that they are merely consultants and become more active participants in patient care by embracing greater patient interaction. The traditional business model for radiology practices, which devalues interaction between patients and radiologists, must be transformed into a patient-centered model in which radiologists are reintegrated into direct patient care and imaging processes are reorganized around patients' needs and preferences. Expanding radiology's core assets to include direct patient care may be the most effective deterrent to the threat of commoditization. As the assault on the growth of Medicare spending continues, with medical imaging as a highly visible target, radiologists must adapt to the changing landscape by focusing on their most important consumer: the patient. This may yield substantial benefits in the form of improved quality and patient safety, reduced costs, higher-value care, improved patient outcomes, and greater patient and provider satisfaction. PMID:26466190

  9. Radiological sinonasal anatomy

    PubMed Central

    Alrumaih, Redha A.; Ashoor, Mona M.; Obidan, Ahmed A.; Al-Khater, Khulood M.; Al-Jubran, Saeed A.

    2016-01-01

    Objectives: To assess the prevalence of common radiological variants of sinonasal anatomy among Saudi population and compare it with the reported prevalence of these variants in other ethnic and population groups. Methods: This is a retrospective cross-sectional study of 121 computerized tomography scans of the nose and paranasal sinuses of patients presented with sinonasal symptoms to the Department of Otorhinolarngology, King Fahad Hospital of the University, Khobar, Saudi Arabia, between January 2014 and May 2014. Results: Scans of 121 patients fulfilled inclusion criteria were reviewed. Concha bullosa was found in 55.4%, Haller cell in 39.7%, and Onodi cell in 28.9%. Dehiscence of the internal carotid artery was found in 1.65%. Type-1 and type-2 optic nerve were the prevalent types. Type-II Keros classification of the depth of olfactory fossa was the most common among the sample (52.9%). Frontal cells were found in 79.3%; type I was the most common. Conclusions: There is a difference in the prevalence of some radiological variants of the sinonasal anatomy between Saudi population and other study groups. Surgeon must pay special attention in the preoperative assessment of patients with sinonasal pathology to avoid undesirable complications. PMID:27146614

  10. [Interventional radiology treatment of extensive pulmonary embolism and thromboembolic diseases].

    PubMed

    Battyáni, István; Dósa, Edit; Harmat, Zoltán

    2015-04-26

    The authors discuss interventional radiological methods in the field of vascular interventions applied in venous system diseases. Venous diseases can be life threatening without appropriate treatment and can lead to chronic venous diseases and venous insufficiency with long-term reduction in the quality of life. In addition, recurrent clinical symptoms require additional treatments. Interventional radiology has several methods that can provide fast and complete recovery if applied in time. The authors summarize these methods hoping that they will be available for a wide range of patients through the establishment of Interventional Radiological Centres and will be a part of the daily routine of patient care. Regarding the frequency of venous diseases and its influance on life quality the authors would like to draw attention to interventional radiological techniques and modern therapeutic possibilities. PMID:26047150

  11. An inverse modeling method to assess the source term of the Fukushima Nuclear Power Plant accident using gamma dose rate observations

    NASA Astrophysics Data System (ADS)

    Saunier, O.; Mathieu, A.; Didier, D.; Tombette, M.; Quélo, D.; Winiarek, V.; Bocquet, M.

    2013-11-01

    The Chernobyl nuclear accident, and more recently the Fukushima accident, highlighted that the largest source of error on consequences assessment is the source term, including the time evolution of the release rate and its distribution between radioisotopes. Inverse modeling methods, which combine environmental measurements and atmospheric dispersion models, have proven efficient in assessing source term due to an accidental situation (Gudiksen, 1989; Krysta and Bocquet, 2007; Stohl et al., 2012a; Winiarek et al., 2012). Most existing approaches are designed to use air sampling measurements (Winiarek et al., 2012) and some of them also use deposition measurements (Stohl et al., 2012a; Winiarek et al., 2014). Some studies have been performed to use dose rate measurements (Duranova et al., 1999; Astrup et al., 2004; Drews et al., 2004; Tsiouri et al., 2012) but none of the developed methods were carried out to assess the complex source term of a real accident situation like the Fukushima accident. However, dose rate measurements are generated by the most widespread measurement system, and in the event of a nuclear accident, these data constitute the main source of measurements of the plume and radioactive fallout during releases. This paper proposes a method to use dose rate measurements as part of an inverse modeling approach to assess source terms. The method is proven efficient and reliable when applied to the accident at the Fukushima Daiichi Nuclear Power Plant (FD-NPP). The emissions for the eight main isotopes 133Xe, 134Cs, 136Cs, 137Cs, 137mBa, 131I, 132I and 132Te have been assessed. Accordingly, 105.9 PBq of 131I, 35.8 PBq of 132I, 15.5 PBq of 137Cs and 12 134 PBq of noble gases were released. The events at FD-NPP (such as venting, explosions, etc.) known to have caused atmospheric releases are well identified in the retrieved source term. The estimated source term is validated by comparing simulations of atmospheric dispersion and deposition with

  12. PM over summertime India: Sources and trends investigated using long term measurements and multi-receptor site back trajectory analysis

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod; Sarkar, Chinmoy; Sachan, Himanshu; Kumar, Devender; Sinha, Baerbel

    2013-04-01

    We apply multi-receptor site residence-time weighted concentration back trajectory analysis to a ten year data set (1991-2003) of PM10 and TSP measurement data from four Indian megacities Delhi, Mumbai, Kolkata and Chennai. The dataset was sourced from the published and peer reviewed work of Gupta and Kumar (2006). Sources and trends of PM10 and TSP during the pre-monsoon season (March-June) were investigated. Residence-time weighted concentration maps were derived using 72 hour HYSPLIT back trajectory ensemble calculations. Trajectory runs were started 100 m AGL and the observed PM monthly averages were attributed to all trajectory runs in a month and each trajectory of the ensemble runs with equal probability. For investigating trends the dataset was further subdivided into two groups of four year durations each (1992-1995 and 2000-2003). We found a linear correlation with a slope of 1.0 (R2=0.9) between estimated seasonal average TSP (2000-2003) using our approach and the measured seasonal averages (2006-2007) for Kanpur, Ahmedabad, Pune and Bangalore. A linear fit between predicted and measured PM10 concentration for 19 sites with PM10 observations of at least one seasonal average between 1999-2009 shows a slope of 1.4 (R2=0.4). For the observation period 2000-2003, the Thar Desert and Taklimakan Desert emerged as largest sources for both PM10 (>180 μg/m3 and >200 μg/m3 respectively) and TSP (>650 μg/m3 and >725 μg/m3 respectively). In-situ observation at Bikaner (central Thar Desert) and in Jhunjhunu (semi-arid site at the border of the Thar Desert) indicate that both TSP and PM10 inside the desert source region are underpredicted by a factor of 10 compared to in-situ observations while for the semi arid area bordering the desert PM10 and TSP are underpredicted by a factor of 5 and 3 respectively. This indicates that strong sources are underpredicted by a receptor site centred approach. The entire North-Western Indo-Gangetic Basin (NW-IGB), where crop

  13. Source portioning of N_{2}O emissions after long term elevation of soil temperature in a permanent grassland soil

    NASA Astrophysics Data System (ADS)

    Jansen-Willems, Anne; Lanigan, Gary; Clough, Timothy; Andresen, Louise; Müller, Christoph

    2016-04-01

    Several methods, such as source portioning, have been used to quantify the contributions of individual N pools to N2O emissions. These methods however, assume the absence of hybrid reactions such as co-denitrification, which were previously identified as important. A straight forward method portioning N2O fluxes into four different production processes, including a hybrid reaction, was therefore developed. This method portioned the N2O fluxes in nitrification, denitrification, oxidation of organic matter and co-denitrification, using data on 45R and 46R of the N2O flux and the 15N content of the NO3‑ and NH4+ in the soil. This newly developed method was used to analyse the N2O emissions from incubated soil, which was previously subjected to 6 years of elevated soil temperature of +0, +1, +2 or +3 ° C. N2O emissions were measured and analysed at four time points in the six days following, NO315NH4 Gly or 15NO3NH4 Gly, label addition. The oxidation of organic N was found to be the main source of N2O fluxes at all sampling dates, comprising between 63 and 85% of the total N2O flux. The percentage contribution made by organic N to N2O fluxes increased over the sampling period, rising from a minimum of 40% in the control treatment, to virtually 100% across all treatments by Day 6. Compared to the control treatment, denitrification contributed less to N2O from soil subjected to +2 and +3 ° C warming (p <0.0001 and p=0.002, respectively). Co-denitrification only contributed to the N2O flux during the first day after substrate addition. The highest amount of N2O produced via co-denitrification was found under the control treatment. From soil subjected to +2 and +3 ° C treatments, the contribution of co-denitrification was minor. However, these differences in co-denitrification were not significant. This research showed the importance of the oxidation of organic N in N2O emissions. It should therefore not be omitted as a potential source in source portioning. Emissions

  14. The influence of sources terms on the boundary behavior of the large solutions of quasilinear elliptic equations: the power like case

    NASA Astrophysics Data System (ADS)

    Alarcón, S.; Díaz, G.; Rey, J. M.

    2013-06-01

    We study the explosive expansion near the boundary of the large solutions of the equation -Δpu+um=f quadin Ω where {Ω} is an open bounded set of {{R}N} , N > 1, with adequately smooth boundary, m > p-1 > 0, and f is a continuous nonnegative function in {Ω} . Roughly speaking, we show that the number of explosive terms in the asymptotic boundary expansion of the solution is finite, but it goes to infinity as m goes to p-1. For illustrative choices of the sources, we prove that the expansion consists of two possible geometrical and nongeometrical parts. For low explosive sources, the nongeometrical part does not exist, and all coefficients depend on the diffusion and the geometry of the domain. For high explosive sources, there are coefficients, relative to the nongeometrical part, independent on {Ω} and the diffusion. In this case, the geometrical part cannot exist, and we say then that the source is very high explosive. We emphasize that low or high explosive sources can cause different geometrical properties in the expansion for a given interior structure of the differential operator. This paper is strongly motivated by the applications, in particular by the non-Newtonian fluid theory where p ≠ 2 involves rheological properties of the medium.

  15. Common problems in gastrointestinal radiology

    SciTech Connect

    Thompson, W.M.

    1989-01-01

    This book covers approximately 70 common diagnostic problems in gastro-intestinal radiology. Each problem, includes a short illustrated case history, a discussion of the radiologic findings, a general discussion of the case, the differential diagnosis, a description of the management of the problem or procedure used, and, where appropriate, the results of the therapy suggested.

  16. Handbooks in radiology: Nuclear medicine

    SciTech Connect

    Datz, F.L.

    1988-01-01

    This series of handbooks covers the basic facts, major concepts and highlights in seven radiological subspecialties. ''Nuclear Medicine'' is a review of the principles, procedures and clinical applications that every radiology resident and practicing general radiologist should know about nuclear medicine. Presented in an outline format it covers all of the organ systems that are imaged by nuclear medicine.

  17. Radiological Technology. Secondary Curriculum Guide.

    ERIC Educational Resources Information Center

    Simpson, Bruce; And Others

    This curriculum guide was designed for use in postsecondary radiological technology education programs in Georgia. Its purpose is to provide for the development of entry level skills in radiological technology in the areas of knowledge, theoretical structure, tool usage, diagnostic ability, related supportive skills, and occupational survival…

  18. Radiological Worker Computer Based Training

    Energy Science and Technology Software Center (ESTSC)

    2003-02-06

    Argonne National Laboratory has developed an interactive computer based training (CBT) version of the standardized DOE Radiological Worker training program. This CD-ROM based program utilizes graphics, animation, photographs, sound and video to train users in ten topical areas: radiological fundamentals, biological effects, dose limits, ALARA, personnel monitoring, controls and postings, emergency response, contamination controls, high radiation areas, and lessons learned.

  19. A global wave parameter database for geophysical applications. Part 2: Model validation with improved source term parameterization

    NASA Astrophysics Data System (ADS)

    Rascle, Nicolas; Ardhuin, Fabrice

    2013-10-01

    A multi-scale global hindcast of ocean waves is presented that covers the years 1994-2012, based on recently published parameterizations for wind sea and swell dissipation [Ardhuin, F., Rogers, E., Babanin, A., Filipot, J.-F., Magne, R., Roland, A., van der Westhuysen, A., Queffeulou, P., Lefevre, J.-M., Aouf, L., Collard, F., 2010. Semi-empirical dissipation source functions for wind-wave models: Part I. Definition, calibration and validation. J. Phys. Oceanogr. 40 (9), 1917-1941]. Results from this hindcast include traditional wave parameters, like the significant wave height and mean periods, and we particularly consider the accuracy of the results for phenomenal sea states, with significant heights above 14 m. Using unbiased winds, there is no evidence of a bias in wave heights even for this very high range. Various spectral moments were also validated, including the surface Stokes drift and mean square slopes that are relevant for wave-current interactions modelling and remote sensing, and also spectra of seismic noise sources. The estimation of these parameters is made more accurate by the new wave growth and dissipation parameterizations. Associated air-sea fluxes of momentum and energy are significantly different from what is obtained with the WAM-Cycle 4 parameterization, with a roughness that is practically a function of wind speed only. That particular output of the model does not appear very realistic and will require future adjustments of the generation and dissipation parameterizations.

  20. Long-term reliability of the Athabasca River (Alberta, Canada) as the water source for oil sands mining

    NASA Astrophysics Data System (ADS)

    St-Jacques, J. M.; Sauchyn, D.; Luckman, B. H.

    2015-12-01

    Exploitation of the Alberta oil sands, the world's third largest crude oil reserve, requires fresh water from the Athabasca River, an allocation of 4.4% of the mean annual flow. This allocation takes into account seasonal fluctuations but not long-term climatic variability and change. This paper examines the decadal-scale variability in river discharge in the Athabasca River Basin (ARB) with 1) a generalized-least-squares (GLS) regression analysis of the trend and variability in gauged flow, and 2) a 900-year tree-ring reconstruction of the water-year flow of the Athabasca River at Athabasca, Alberta. The GLS analysis removes confounding transient trends related to the Pacific Decadal Oscillation (PDO) and Pacific North American mode (PNA). It shows long-term declining flows throughout the ARB. The tree-ring record reveals a larger range of flows and severity of hydrologic deficits than those captured by the instrumental records that are the basis for surface water allocation. It includes periods of sustained low flow of multiple decades in duration, suggesting the influence of the PDO and PNA teleconnections. These results together demonstrate that low-frequency variability must be considered in ARB water allocation, which has not been the case. We show that the current and projected surface water allocations from the Athabasca River for the exploitation of the Alberta oil sands are based on an untenable assumption of the representativeness of the short instrumental record.

  1. Long-term reliability of the Athabasca River (Alberta, Canada) as the water source for oil sands mining

    PubMed Central

    Sauchyn, David J.; St-Jacques, Jeannine-Marie; Luckman, Brian H.

    2015-01-01

    Exploitation of the Alberta oil sands, the world’s third-largest crude oil reserve, requires fresh water from the Athabasca River, an allocation of 4.4% of the mean annual flow. This allocation takes into account seasonal fluctuations but not long-term climatic variability and change. This paper examines the decadal-scale variability in river discharge in the Athabasca River Basin (ARB) with (i) a generalized least-squares (GLS) regression analysis of the trend and variability in gauged flow and (ii) a 900-y tree-ring reconstruction of the water-year flow of the Athabasca River at Athabasca, Alberta. The GLS analysis removes confounding transient trends related to the Pacific Decadal Oscillation (PDO) and Pacific North American mode (PNA). It shows long-term declining flows throughout the ARB. The tree-ring record reveals a larger range of flows and severity of hydrologic deficits than those captured by the instrumental records that are the basis for surface water allocation. It includes periods of sustained low flow of multiple decades in duration, suggesting the influence of the PDO and PNA teleconnections. These results together demonstrate that low-frequency variability must be considered in ARB water allocation, which has not been the case. We show that the current and projected surface water allocations from the Athabasca River for the exploitation of the Alberta oil sands are based on an untenable assumption of the representativeness of the short instrumental record. PMID:26392554

  2. Modification to ORIGEN2 for generating N Reactor source terms. Volume 2: ORIGEN2 N-Reactor output files

    SciTech Connect

    1997-06-01

    This text is intended to be a brief outline of the ORIGEN2 computer code, which is a revised and updated version of the ORIGEN documented i report ORNL-4628 (May 1973). Included here are: a brief description of the functions of ORIGEN2; a listing of the major data sources; a listing of the published documentation concerning ORIGEN2; and an outline of the ORIGEN2 output organization. ORIGEN2 is a available from the ORNL Radiation Shielding Information Center (RSIC). Past experience has indicated that many users encounter considerable difficulty in finding the desired information in ORIGEN2 output which is sometimes rather massive. This section is intended as a brief outline of the organization of ORIGEN2 output.

  3. Modifications to ORIGEN2 for generating N Reactor source terms. Volume 3: ORIGEN2 N-Reactor output files

    SciTech Connect

    1997-06-01

    This text is intended to be a brief outline of the ORIGEN2 computer code which is a revised and updated version of the ORIGEN documented in report ORNL-4628 (May 1973). Included here are: a brief description of the functions of ORIGEN2; a listing of the major data sources; a listing of the published documentation concerning ORIGEN2; and an outline of the ORIGEN2 output organization. ORIGEN2 is available from the ORNL Radiation Shielding Information Center (RSIC). Past experience has indicated that many users encounter considerable difficulty in finding the desired information in a ORIGEN2 output which is sometimes rather massive. This section is intended as a brief outline of the organization of ORIGEN2 output.

  4. Disposal Unit Source Term by One-Dimensional, Transient, Finite-Difference, Subsurface Release and Transport of Contaminants.

    Energy Science and Technology Software Center (ESTSC)

    1995-07-07

    DUST solves for release and transport of contaminants from containerized wastes. Each container may have unique properties (i.e., time to failure or localized failure, e.g., pitting) and each waste form may have unique release properties. Release from the waste form is limited by one of four physical or chemical restraints: solubility, diffusion, dissolution, and surface wash-off with partitioning. The release from the waste form acts as a source for transport in the advection/dispersion equation. Transportmore » is modeled in one-dimension through the groundwater pathway from subsurface disposal. RNUCL.DAT, database of half-lives, solubility limits, and atomic mass for selected radionuclides, is included in this package.« less

  5. Nitrate sources and sinks in Elkhorn Slough, California: Results from long-term continuous in situ nitrate analyzers

    USGS Publications Warehouse

    Chapin, T.P.; Caffrey, J.M.; Jannasch, H.W.; Coletti, L.J.; Haskins, J.C.; Johnson, K.S.

    2004-01-01

    Nitrate and water quality parameters (temperature, salinity, dissolved oxygen, turbidity, and depth) were measured continuously with in situ NO 3 analyzers and water quality sondes at two sites in Elkhorn Slough in Central California. The Main Channel site near the mouth of Elkhorn Slough was sampled from February to September 2001. Azevedo Pond, a shallow tidal pond bordering agricultural fields further inland, was sampled from December 1999 to July 2001. Nitrate concentrations were recorded hourly while salinity, temperature, depth, oxygen, and turbidity were recorded every 30 min. Nitrate concentrations at the Main Channel site ranged from 5 to 65 ??M. The propagation of an internal wave carrying water from ???100 m depth up the Monterey Submarine Canyon and into the lower section of Elkhorn Slough on every rising tide was a major source of nitrate, accounting for 80-90% of the nitrogen load during the dry summer period. Nitrate concentrations in Azevedo Pond ranged from 0-20 ??M during the dry summer months. Nitrate in Azevedo Pond increased to over 450 ??M during a heavy winter precipitation event, and interannual variability driven by differences in precipitation was observed. At both sites, tidal cycling was the dominant forcing, often changing nitrate concentrations by 5-fold or more within a few hours. Water volume flux estimates were combined with observed nitrate concentrations to obtain nitrate fluxes. Nitrate flux calculations indicated a loss of 4 mmol NO3 m -2 d-1 for the entire Elkhorn Slough and 1 mmol NO 3 m-2 d-1 at Azevedo Pond. These results suggested that the waters of Elkhorn Slough were not a major source of nitrate to Monterey Bay but actually a nitrate sink during the dry season. The limited winter data at the Main Channel site suggest that nitrate was exported from Elkhorn Slough during the wet season. Export of ammonium or dissolved organic nitrogen, which we did not monitor, may balance some or all of the NO 3 flux.

  6. Effect of the Presence of Long Term Correlated Common Source Fluctuations to the Heart Rate Feedback Analysis

    NASA Astrophysics Data System (ADS)

    Nishiyama, S.; Yana, K.; Mizuta, H.; Ono, T.

    2007-07-01

    This paper investigates the effect of the presence of long term correlated common driving forces to the bivariate autoregressive (BAR) analysis for the closed loop characterization of heart rate fluctuations (HRF) and systolic blood pressure change (SBP). It has been shown that the estimation accuracy decreases as common noise power and Hurst parameter value increases. However, the accuracy is acceptable even with relatively high common driving force power at 50% and with high Hurst parameter values at 0.95. The relative mean squared error in the impulse response estimation is shown to be 12% in that ill condition. As an illustrative example of the bivariate fluctuation analysis, the change in impulse responses between HRF and SBP due to the water intake has been examined.

  7. AERIAL RADIOLOGICAL SURVEYS

    SciTech Connect

    Proctor, A.E.

    1997-06-09

    Measuring terrestrial gamma radiation from airborne platforms has proved to be a useful method for characterizing radiation levels over large areas. Over 300 aerial radiological surveys have been carried out over the past 25 years including U.S. Department of Energy (DOE) sites, commercial nuclear power plants, Formerly Utilized Sites Remedial Action Program/Uranium Mine Tailing Remedial Action Program (FUSRAP/UMTRAP) sites, nuclear weapons test sites, contaminated industrial areas, and nuclear accident sites. This paper describes the aerial measurement technology currently in use by the Remote Sensing Laboratory (RSL) for routine environmental surveys and emergency response activities. Equipment, data-collection and -analysis methods, and examples of survey results are described.

  8. Standardized radiological dose evaluations

    SciTech Connect

    Peterson, V.L.; Stahlnecker, E.

    1996-05-01

    Following the end of the Cold War, the mission of Rocky Flats Environmental Technology Site changed from production of nuclear weapons to cleanup. Authorization baseis documents for the facilities, primarily the Final Safety Analysis Reports, are being replaced with new ones in which accident scenarios are sorted into coarse bins of consequence and frequency, similar to the approach of DOE-STD-3011-94. Because this binning does not require high precision, a standardized approach for radiological dose evaluations is taken for all the facilities at the site. This is done through a standard calculation ``template`` for use by all safety analysts preparing the new documents. This report describes this template and its use.

  9. The yearbook of diagnostic radiology. 1987

    SciTech Connect

    Bragg, D.G.

    1987-01-01

    This book contains seven selections. They are: Neuroradiology; Cardiovascular and Interventional Radiology; The Thorax; The Abdomen; The Musculoskeletal System; Pediatric Radiology; and Radiation Physics.

  10. Radiological Image Compression

    NASA Astrophysics Data System (ADS)

    Lo, Shih-Chung Benedict

    The movement toward digital images in radiology presents the problem of how to conveniently and economically store, retrieve, and transmit the volume of digital images. Basic research into image data compression is necessary in order to move from a film-based department to an efficient digital -based department. Digital data compression technology consists of two types of compression technique: error-free and irreversible. Error -free image compression is desired; however, present techniques can only achieve compression ratio of from 1.5:1 to 3:1, depending upon the image characteristics. Irreversible image compression can achieve a much higher compression ratio; however, the image reconstructed from the compressed data shows some difference from the original image. This dissertation studies both error-free and irreversible image compression techniques. In particular, some modified error-free techniques have been tested and the recommended strategies for various radiological images are discussed. A full-frame bit-allocation irreversible compression technique has been derived. A total of 76 images which include CT head and body, and radiographs digitized to 2048 x 2048, 1024 x 1024, and 512 x 512 have been used to test this algorithm. The normalized mean -square-error (NMSE) on the difference image, defined as the difference between the original and the reconstructed image from a given compression ratio, is used as a global measurement on the quality of the reconstructed image. The NMSE's of total of 380 reconstructed and 380 difference images are measured and the results tabulated. Three complex compression methods are also suggested to compress images with special characteristics. Finally, various parameters which would effect the quality of the reconstructed images are discussed. A proposed hardware compression module is given in the last chapter.

  11. Action research regarding the optimisation of radiological protection for nurses during vascular interventional radiology.

    PubMed

    Mori, Hiroshige

    2015-06-01

    The optimisation and decision-making processes for radiological protection have been broadened by the introduction of re-examination or feedback after introducing protective measures. In this study, action research was used to reduce the occupational exposure of vascular interventional radiology (IR) nurses. Four radiological protection improvement measures were continuously performed in cooperation with the researchers, nurses and stakeholders, and the nurses' annual effective doses were compared before and after the improvements. First, the dosimetry equipment was changed from one electronic personal dosimeter (EPD) to two silver-activated phosphate glass dosimeters (PGDs). Second, the nurses were educated regarding maintaining a safe distance from the sources of scattered and leakage radiation. Third, portable radiation shielding screens were placed in the IR rooms. Fourth, the x-ray units' pulse rates were reduced by half. On changing the dosimetry method, the two PGDs recorded a 4.4 fold greater dose than the single EPD. Educating nurses regarding radiological protection and reducing the pulse rates by half decreased their effective doses to one-third and two-fifths of the baseline dose, respectively. No significant difference in their doses was detected after the placement of the shielding screens. Therefore, the action research effectively decreased the occupational doses of the vascular IR nurses. PMID:26052718

  12. Radiology and the mobile device: Radiology in motion.

    PubMed

    Panughpath, Sridhar G; Kalyanpur, Arjun

    2012-10-01

    The use of mobile devices is revolutionizing the way we communicate, interact, are entertained, and organize our lives. With healthcare in general and radiology in particular becoming increasingly digital, the use of such devices in radiologic practice is inevitable. This article reviews the current status of the use of mobile devices in the clinical practice of radiology, namely in emergency teleradiology. Technical parameters such as luminance and resolution are discussed. The article also discusses the benefits of such mobility vis-à-vis the current limitations of the technologies available. PMID:23833412

  13. The geomagnetically trapped radiation environment: A radiological point of view

    NASA Technical Reports Server (NTRS)

    Holly, F. E.

    1972-01-01

    The regions of naturally occurring, geomagnetically trapped radiation are briefly reviewed in terms of physical parameters such as; particle types, fluxes, spectrums, and spatial distributions. The major emphasis is placed upon a description of this environment in terms of the radiobiologically relevant parameters of absorbed dose and dose-rate and a discussion of the radiological implications in terms of the possible impact on space vehicle design and mission planning.

  14. Is fire a long term sink or source of atmospheric carbon? A comprehensive evaluation of a boreal forest fire

    NASA Astrophysics Data System (ADS)

    Santin, C.; Doerr, S. H.; Preston, C.; Bryant, R.

    2012-12-01

    Fires lead to a rapid release of carbon (C) from forest and other fire-prone ecosystems, emitting important quantities of C to the atmosphere. Every year 300-600 Mill. ha burn around the globe, generating CO2 emissions equivalent to half of the current annual global from fossil fuel combustion. Over the longer-term vegetation fires are widely considered as 'net zero Carbon (C) emission events', because C emissions from fires, excluding those associated with deforestation, are balanced by C uptake by regenerating vegetation. This 'zero C emission' scenario, however, may be flawed, as it does not consider the role of pyrogenic C (PyC). During fire, some of the fuel is transformed into PyC (i.e. charcoal, black C, soot), which is characterized by an enhanced recalcitrance and a longer mean residence time in the environment than its 'fresh' precursors. Therefore, after complete regeneration of the vegetation, the PyC generated represents an additional longer-term C pool and, hence, recurring fire-regrowth cycles could be considered as a 'net sink of atmospheric C'. To test the validity of this hypothesis, and to estimate how quantitatively important this PyC pool might be, accurate data on PyC production with respect to the fuel combusted are needed. Unfortunately, detailed quantification of fuel prior to fire is normally only available for prescribed and experimental fires, which are usually of low-intensity and therefore not representative of higher-intensity wildfires. Furthermore, what little data is available is usually based on only a specific fraction of the PyC present following burning rather than the whole range of PyC products and stores (i.e. PyC in soil, ash, downed wood and standing vegetation). The FireSmart project (Ft. Providence, NWT, Canada, June 2012) provided the ideal framework to address this research gap. This experimental fire reproduced wildfire conditions in boreal forest, i.e. stand-replacing crown fire and, at the same time, allowed i) pre

  15. Interventional Radiologic Treatment for Idiopathic Portal Hypertension

    SciTech Connect

    Hirota, Shozo; Ichikawa, Satoshi; Matsumoto, Shinichi; Motohara, Tomofumi; Fukuda, Tetsuya; Yoshikawa, Takeshi

    1999-07-15

    Purpose: To evaluate the usefulness of interventional radiological treatment for idiopathic portal hypertension. Methods: Between 1995 and 1998, we performed an interventional radiological treatment in five patients with idiopathic portal hypertension, four of whom had refused surgery and one of whom had undergone surgery. Three patients with gastroesophageal varices (GEV) were treated by partial splenic embolization (PSE), one patient with esophageal varices (EV) and massive ascites by transjugular intrahepatic portosytemic shunt (TIPS) and PSE, and one patient with GEV by percutaneous transhepatic obliteration (PTO). Midterm results were analyzed in terms of the effect on esophageal and/or gastric varices. Results: In one woman with severe GEV who underwent three sessions of PSE, there was endoscopic confirmation that the GEV had disappeared. In one man his EV shrunk markedly after two sessions of PSE. In two patients slight reduction of the EV was obtained with one application of PSE combined with endoscopic variceal ligation therapy. PTO for GV in one patient resulted in good control of the varices. All patients have survived for 16-42 months since the first interventional treatment, and varices are well controlled. Conclusion: Interventional radiological treatment is effective for patients with idiopathic portal hypertension, whether or not they have undergone surgery.

  16. Evaluation of the Hydrologic Source Term from Underground Nuclear Tests on Pahute Mesa at the Nevada Test Site: The CHESHIRE Test

    SciTech Connect

    Pawloski, G A; Tompson, A F B; Carle, S F; Bourcier, W L; Bruton, C J; Daniels, J I; Maxwell, R M; Shumaker, D E; Smith, D K; Zavarin, M

    2001-05-01

    The objectives of this report are to develop, summarize, and interpret a series of detailed unclassified simulations that forecast the nature and extent of radionuclide release and near-field migration in groundwater away from the CHESHIRE underground nuclear test at Pahute Mesa at the NTS over 1000 yrs. Collectively, these results are called the CHESHIRE Hydrologic Source Term (HST). The CHESHIRE underground nuclear test was one of 76 underground nuclear tests that were fired below or within 100 m of the water table between 1965 and 1992 in Areas 19 and 20 of the NTS. These areas now comprise the Pahute Mesa Corrective Action Unit (CAU) for which a separate subregional scale flow and transport model is being developed by the UGTA Project to forecast the larger-scale migration of radionuclides from underground tests on Pahute Mesa. The current simulations are being developed, on one hand, to more fully understand the complex coupled processes involved in radionuclide migration, with a specific focus on the CHESHIRE test. While remaining unclassified, they are as site specific as possible and involve a level of modeling detail that is commensurate with the most fundamental processes, conservative assumptions, and representative data sets available. However, the simulation results are also being developed so that they may be simplified and interpreted for use as a source term boundary condition at the CHESHIRE location in the Pahute Mesa CAU model. In addition, the processes of simplification and interpretation will provide generalized insight as to how the source term behavior at other tests may be considered or otherwise represented in the Pahute Mesa CAU model.

  17. Possible source term of high concentrations of mecoprop-p in leachate and water quality: impact of climate change, public use and disposal.

    PubMed

    Idowu, I A; Alkhaddar, R M; Atherton, W

    2014-08-01

    Mecoprop-p herbicide is often found in wells and water abstractions in many areas around Europe, the UK inclusive. There is a growing environmental and public health concern about mecoprop-p herbicide pollution in ground and surface water in England. Reviews suggest that extensive work has been carried out on the contribution of mecoprop-p herbicides from agricultural use whilst more work needs to be carried out on the contribution of mecoprop-p herbicide from non-agricultural use. The study covers two landfill sites in Weaver/Gowy Catchment. Mecoprop-p herbicide concentrations in the leachate quality range between 0.06 and 290 microg l1 in cells. High concentration ofmecoprop-p herbicide in the leachate quality suggests that there is a possible source term in the waste stream. This paper addresses the gap by exploring possible source terms of mecoprop-p herbicide contamination on landfill sites and evaluates the impact of public purchase, use and disposal alongside climate change on seasonal variations in mecoprop-p concentrations. Mecoprop-p herbicide was found to exceed the EU drinking water quality standards at the unsaturated zone/aquifer with observed average concentrations ranging between 0.005 and 7.96 microg l1. A route map for mecoprop-p herbicide source term contamination is essential for mitigation and pollution management with emphasis on both consumer and producer responsibility towards use of mecoprop-p product. In addition, improvement in data collection on mecoprop-p concentrations and detailed seasonal herbicide sales for non-agricultural purposes are needed to inform the analysis and decision process. PMID:24956800

  18. Short-term nitrogen additions can shift a coastal wetland from a sink to a source of N2O

    USGS Publications Warehouse

    Moseman-Valtierra, S.; Gonzalez, R.; Kroeger, K.D.; Tang, J.; Chao, W.C.; Crusius, J.; Bratton, J.; Green, A.; Shelton, J.

    2011-01-01

    Coastal salt marshes sequester carbon at high rates relative to other ecosystems and emit relatively little methane particularly compared to freshwater wetlands. However, fluxes of all major greenhouse gases (N2O, CH4, and CO2) need to be quantified for accurate assessment of the climatic roles of these ecosystems. Anthropogenic nitrogen inputs (via run-off, atmospheric deposition, and wastewater) impact coastal marshes. To test the hypothesis that a pulse of nitrogen loading may increase greenhouse gas emissions from salt marsh sediments, we compared N2O, CH4 and respiratory CO2 fluxes from nitrate-enriched plots in a Spartina patens marsh (receiving single additions of NaNO3 equivalent to 1.4 g N m-2) to those from control plots (receiving only artificial seawater solutions) in three short-term experiments (July 2009, April 2010, and June 2010). In July 2009, we also compared N2O and CH4 fluxes in both opaque and transparent chambers to test the influence of light on gas flux measurements. Background fluxes of N2O in July 2009 averaged -33 ??mol N2O m-2 day-1. However, within 1 h of nutrient additions, N2O fluxes were significantly greater in plots receiving nitrate additions relative to controls in July 2009. Respiratory rates and CH4 fluxes were not significantly affected. N2O fluxes were significantly higher in dark than in transparent chambers, averaging 108 and 42 ??mol N2O m-2 day-1 respectively. After 2 days, when nutrient concentrations returned to background levels, none of the greenhouse gas fluxes differed from controls. In April 2010, N2O and CH4 fluxes were not significantly affected by nitrate, possibly due to higher nitrogen demands by growing S. patens plants, but in June 2010 trends of higher N2O fluxes were again found among nitrate-enriched plots, indicating that responses to nutrient pulses may be strongest during the summer. In terms of carbon equivalents, the highest average N2O and CH4 fluxes observed, exceeded half the magnitude of typical

  19. Short-term nitrogen additions can shift a coastal wetland from a sink to a source of N 2O

    NASA Astrophysics Data System (ADS)

    Moseman-Valtierra, Serena; Gonzalez, Rosalinda; Kroeger, Kevin D.; Tang, Jianwu; Chao, Wei Chun; Crusius, John; Bratton, John; Green, Adrian; Shelton, James

    2011-08-01

    Coastal salt marshes sequester carbon at high rates relative to other ecosystems and emit relatively little methane particularly compared to freshwater wetlands. However, fluxes of all major greenhouse gases (N 2O, CH 4, and CO 2) need to be quantified for accurate assessment of the climatic roles of these ecosystems. Anthropogenic nitrogen inputs (via run-off, atmospheric deposition, and wastewater) impact coastal marshes. To test the hypothesis that a pulse of nitrogen loading may increase greenhouse gas emissions from salt marsh sediments, we compared N 2O, CH 4 and respiratory CO 2 fluxes from nitrate-enriched plots in a Spartina patens marsh (receiving single additions of NaNO 3 equivalent to 1.4 g N m -2) to those from control plots (receiving only artificial seawater solutions) in three short-term experiments (July 2009, April 2010, and June 2010). In July 2009, we also compared N 2O and CH 4 fluxes in both opaque and transparent chambers to test the influence of light on gas flux measurements. Background fluxes of N 2O in July 2009 averaged -33 μmol N 2O m -2 day -1. However, within 1 h of nutrient additions, N 2O fluxes were significantly greater in plots receiving nitrate additions relative to controls in July 2009. Respiratory rates and CH 4 fluxes were not significantly affected. N 2O fluxes were significantly higher in dark than in transparent chambers, averaging 108 and 42 μmol N 2O m -2 day -1 respectively. After 2 days, when nutrient concentrations returned to background levels, none of the greenhouse gas fluxes differed from controls. In April 2010, N 2O and CH 4 fluxes were not significantly affected by nitrate, possibly due to higher nitrogen demands by growing S. patens plants, but in June 2010 trends of higher N 2O fluxes were again found among nitrate-enriched plots, indicating that responses to nutrient pulses may be strongest during the summer. In terms of carbon equivalents, the highest average N 2O and CH 4 fluxes observed, exceeded half

  20. Exact Solution of Fractional Diffusion Model with Source Term used in Study of Concentration of Fission Product in Uranium Dioxide Particle

    NASA Astrophysics Data System (ADS)

    Fang, Chao; Cao, Jian-Zhu; Sun, Li-Feng

    2011-05-01

    The exact solution of fractional diffusion model with a location-independent source term used in the study of the concentration of fission product in spherical uranium dioxide (UO2) particle is built. The adsorption effect of the fission product on the surface of the UO2 particle and the delayed decay effect are also considered. The solution is given in terms of Mittag—Leffler function with finite Hankel integral transformation and Laplace transformation. At last, the reduced forms of the solution under some special physical conditions, which is used in nuclear engineering, are obtained and corresponding remarks are given to provide significant exact results to the concentration analysis of nuclear fission products in nuclear reactor.

  1. Carbon Isotope Ratios Of Carbon Dioxide In The Urban Salt Lake Valley, Utah USA: Source And Long-Term Monitoring Observations

    NASA Astrophysics Data System (ADS)

    Ehleringer, J.; Lai, C.; Strong, C.; Pataki, D. E.; Bowling, D. R.; Schauer, A. J.; Bush, S.

    2011-12-01

    A high-precision, decadal record of carbon isotope ratios in atmospheric carbon dioxide has been produced for the urbanized Salt Lake Valley, Utah USA. These data complement a similar time series of atmospheric carbon dioxide concentrations for different locations in the same urban region. This isotopic record includes diurnal and nocturnal observations based on flask (IRMS-based) and continuous (TDL-based) measurement systems. These data reveal repeatable diurnal and seasonal variations in the anthropogenic and biogenic carbon sources that can be used to reconstruct different source inputs. As the Salt Lake Valley is an isolated urban region, the impacts of local anthropogenic inputs can be distinguished from regional patterns as measured by NOAA at the rural Wendover monitoring station 200 km to the west of the Salt Lake Valley. Complementary data, such as vehicle exhaust, emission from power plants and household furnaces, plant and soil organic matter, are also provided to quantify the carbon isotope ratios of the predominant anthropogenic and biogenic sources within the Salt Lake Valley. The combined source and long-term observational values will be made freely available and their utility is discussed for modeling efforts including urban metabolism modeling and atmospheric trace gas modeling.

  2. Measurement and apportionment of radon source terms for modeling indoor environments. Final progress report, March 1990--August 1992

    SciTech Connect

    Harley, N.H.

    1992-12-31

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor {sup 222}Rn and in {sup 222}Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house {sup 222}Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater {sup 222}Rn concentration than the measured outdoor {sup 222}Rn. Apartment dwellers generally represent a low risk group regarding {sup 222}Rn exposure. The following sections describe the main projects in some detail.

  3. Long term X-ray observations of systems with unusual optical counterparts and modulation measurement of selected astronomical sources

    NASA Technical Reports Server (NTRS)

    Bowyer, C. S.

    1982-01-01

    The OAO-3 satellite was used for several months' observation of the loss mass X-ray binary sources 2A18822-371 and 4U2129+47 in a search for variability similar to the 35 day on-off cycle observed in Her X-1. The related system Cyg X-2 was observed both optically and in X-rays covering one complete binary cycle of 9.8 days. The UCL X-ray telescope observations revealed no periodities nor obvious variability other than the known orbital periods; however, the ground-based optical spectroscopy supports the interpretation of the photometry periodicities as representing orbital motion in 2A1822-371 and detected radial velocity motions on the photometric period in 4U2129+47. The shape and the length of the 4.8 hour periodicity in the X-ray emission from Cyg X-3 was also studied. The quality OAO-3 data obtained to measure the light curve and look for a change in the period and/or obtain improved measurement of the slope of the light curve was insufficient.

  4. Retinal imaging as a source of biomarkers for diagnosis, characterization and prognosis of chronic illness or long-term conditions

    PubMed Central

    Trucco, E; Cameron, J R; Dhillon, B; Houston, J G; van Beek, E J R

    2014-01-01

    The black void behind the pupil was optically impenetrable before the invention of the ophthalmoscope by von Helmholtz over 150 years ago. Advances in retinal imaging and image processing, especially over the past decade, have opened a route to another unexplored landscape, the retinal neurovascular architecture and the retinal ganglion pathways linking to the central nervous system beyond. Exploiting these research opportunities requires multidisciplinary teams to explore the interface sitting at the border between ophthalmology, neurology and computing science. It is from the detail and depth of retinal phenotyping that novel metrics and candidate biomarkers are likely to emerge. Confirmation that in vivo retinal neurovascular measures are predictive of microvascular change in the brain and other organs is likely to be a major area of research activity over the next decade. Unlocking this hidden potential within the retina requires integration of structural and functional data sets, that is, multimodal mapping and longitudinal studies spanning the natural history of the disease process. And with further advances in imaging, it is likely that this area of retinal research will remain active and clinically relevant for many years to come. Accordingly, this review looks at state-of-the-art retinal imaging and its application to diagnosis, characterization and prognosis of chronic illness or long-term conditions. PMID:24936979

  5. Retinal imaging as a source of biomarkers for diagnosis, characterization and prognosis of chronic illness or long-term conditions.

    PubMed

    MacGillivray, T J; Trucco, E; Cameron, J R; Dhillon, B; Houston, J G; van Beek, E J R

    2014-08-01

    The black void behind the pupil was optically impenetrable before the invention of the ophthalmoscope by von Helmholtz over 150 years ago. Advances in retinal imaging and image processing, especially over the past decade, have opened a route to another unexplored landscape, the retinal neurovascular architecture and the retinal ganglion pathways linking to the central nervous system beyond. Exploiting these research opportunities requires multidisciplinary teams to explore the interface sitting at the border between ophthalmology, neurology and computing science. It is from the detail and depth of retinal phenotyping that novel metrics and candidate biomarkers are likely to emerge. Confirmation that in vivo retinal neurovascular measures are predictive of microvascular change in the brain and other organs is likely to be a major area of research activity over the next decade. Unlocking this hidden potential within the retina requires integration of structural and functional data sets, that is, multimodal mapping and longitudinal studies spanning the natural history of the disease process. And with further advances in imaging, it is likely that this area of retinal research will remain active and clinically relevant for many years to come. Accordingly, this review looks at state-of-the-art retinal imaging and its application to diagnosis, characterization and prognosis of chronic illness or long-term conditions. PMID:24936979

  6. Long-term cultured hairy roots of chicory-a rich source of hydroxycinnamates and 8-deoxylactucin glucoside.

    PubMed

    Malarz, Janusz; Stojakowska, Anna; Kisiel, Wanda

    2013-12-01

    A 12-year-old hairy root culture of Cichorium intybus L., a callus culture of the plant as well as roots and leaves of a wild plant of chicory, and roots of two C. intybus L. var. sativum cultivars were examined in respect of their hydroxycinnamate and sesquiterpene lactone compositions and contents. Total phenolics and diphenylpicrylhydrazyl radical scavenging activity of the examined plant tissues were also analyzed. The most active in radical scavenging were extracts from the hairy roots and leaves of chicory. 3,5-Dicaffeoylquinic acid was the major antioxidant present in the hairy roots. Its content in the root biomass reached 5.5 %, calculated on a dry weight basis. 8-Deoxylactucin glucoside (crepidiaside A) was the major sesquiterpene lactone in the hairy roots. Its content reached 1.4 %, calculated on a dry weight basis, and was nearly two orders of magnitude higher than that in the roots of wild chicory plant. The glucosidic derivative of 8-deoxylactucin constituted over 85 % of the total sesquiterpene lactone content in the long-term cultured hairy roots of chicory. Aglycone of this compound was reported to possess anti-inflammatory activity. The qualitative and quantitative analyses of hydroxycinnamates in callus and hairy root cultures of C. intybus were undertaken for the first time. PMID:23975347

  7. A comparison of three-dimensional nonequilibrium solution algorithms applied to hypersonic flows with stiff chemical source terms

    NASA Technical Reports Server (NTRS)

    Palmer, Grant; Venkatapathy, Ethiraj

    1993-01-01

    Three solution algorithms, explicit underrelaxation, point implicit, and lower upper symmetric Gauss-Seidel (LUSGS), are used to compute nonequilibrium flow around the Apollo 4 return capsule at 62 km altitude. By varying the Mach number, the efficiency and robustness of the solution algorithms were tested for different levels of chemical stiffness. The performance of the solution algorithms degraded as the Mach number and stiffness of the flow increased. At Mach 15, 23, and 30, the LUSGS method produces an eight order of magnitude drop in the L2 norm of the energy residual in 1/3 to 1/2 the Cray C-90 computer time as compared to the point implicit and explicit under-relaxation methods. The explicit under-relaxation algorithm experienced convergence difficulties at Mach 23 and above. At Mach 40 the performance of the LUSGS algorithm deteriorates to the point it is out-performed by the point implicit method. The effects of the viscous terms are investigated. Grid dependency questions are explored.

  8. Source term estimation using air concentration measurements and a Lagrangian dispersion model - Experiments with pseudo and real cesium-137 observations from the Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Chai, Tianfeng; Draxler, Roland; Stein, Ariel

    2015-04-01

    A transfer coefficient matrix (TCM) was created in a previous study using a Lagrangian dispersion model to provide plume predictions under different emission scenarios. The TCM estimates the contribution of each emission period to all sampling locations and can be used to estimate source terms by adjusting emission rates to match the model prediction with the measurements. In this paper, the TCM is used to formulate a cost functional that measures the differences between the model predictions and the actual air concentration measurements. The cost functional also includes a background term which adds the differences between a first guess and the updated emission estimates. Uncertainties of the measurements, as well as those for the first guess of source terms are both considered in the cost functional. In addition, a penalty term is added to create a smooth temporal change in the release rate. The method is first tested with pseudo observations generated using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model at the same location and time as the actual observations. The inverse estimation system is able to accurately recover the release rates and performs better than a direct solution using singular value decomposition (SVD). It is found that computing ln(c) differences between model and observations is better than using the original concentration c differences in the cost functional. The inverse estimation results are not sensitive to artificially introduced observational errors or different first guesses. To further test the method, daily average cesium-137 air concentration measurements around the globe from the Fukushima nuclear accident are used to estimate the release of the radionuclide. Compared with the latest estimates by Katata et al. (2014), the recovered release rates successfully capture the main temporal variations. When using subsets of the measured data, the inverse estimation method still manages to identify most of the

  9. Nevada National Security Site Radiological Control Manual

    SciTech Connect

    Radiological Control Managers’ Council

    2012-03-26

    low-level radioactive waste and the handling of radioactive sources. Remediation of contaminated land areas may also result in radiological exposures.

  10. RADRELAY RADIOLOGICAL DATA LINK DEVICE

    SciTech Connect

    Harpring, L; Frank Heckendorn, F

    2007-11-06

    The RadRelay effort developed small, field appropriate, portable prototype devices that allow radiological spectra to be downloaded from field radiological detectors, like the identiFINDER-U, and transmitted to land based experts. This communications capability was designed for the U. S. Coast Guard (USCG) but is also applicable to the Customs and Border Protection (CBP) personnel working in remote locations. USCG Level II personnel currently use the identiFINDER-U Hand-Held Radioisotope ID Devices (HHRIID) to detect radiological materials during specific boarding operations. These devices will detect not only radiological emissions but will also evaluate those emissions against a table of known radiological spectra. The RadRelay has been developed to significantly improve the functionality of HHRIID, by providing the capability to download radiological spectra and then transmit them using satellite or cell phone technology. This remote wireless data transfer reduces the current lengthy delay often encountered between the shipboard detection of unknown radiological material and the evaluation of that data by technical and command personnel. That delay is reduced from hours to minutes and allows the field located personnel to remain on station during the inspection and evaluation process.

  11. Patient radiation exposure in diagnostic radiology examinations: an overview. Summary report

    SciTech Connect

    Burkhart, R.L.

    1983-08-01

    The report surveys the published data on entrance skin exposure received by patients during diagnostic radiology examinations. It provides a reference source to aid radiology facilities in determining whether the amount of exposure received by their patients is appropriate for the diagnostic procedures employed.

  12. Radiological safety at Argonne national laboratory's heavy ion research facility

    NASA Astrophysics Data System (ADS)

    Cooke, R. H.; Wynveen, R. A.

    1985-05-01

    This paper discusses the radiological safety system to be employed at the Argonne tandem—linac accelerator system (ATLAS). The design parameters of ATLAS that affect safety have remained unchanged since ATLAS construction began in 1982. The specialized radiological safety considerations of ATLAS were discussed in 1982 [1]. This paper will present the details of the hardware, the administrative controls, and the radiation monitoring that will be in effect when beam is produced in April 1985. The experimental hall utilizing the maximum energy beam ( ˜ 27 MeV per nucleon) from the completed ATLAS has been partitioned with shielding blocks into its final configuration. Because scientists want access to some of the partitioned-off areas while beam is present in other areas, an interlock and logic system allowing such occupancy has been designed. The rationale and hardware of the system will be discussed. Since one of the potential radiation hazards is high-energy forward-directed neutrons from any location where the beam impinges (such as collimators, bending and focussing systems, experimental targets, and beam stops), radiation surveys and hazard assessments are necessary for the administrative controls that allow occupancy of various areas. Because of the various uses of ATLAS, neutrons (the dominant beam hazard) will be non-existent in some experiments and will be of energies ≳ 10 MeV for a few experiments. These conditions may exist at specific locations during beam preparation but may change rapidly when beam is finally delivered to an experimental area. Monitoring and assessing such time varying and geographically changing hazards will be a challenge since little data will be available on source terms until various beams are produced of sufficient intensity and energy to make measurements. How the operating division for ATLAS and the Argonne safety division are addressing this aspect through administrative controls will also be discussed.

  13. Assessing the long-term probabilistic volcanic hazard for tephra fallout in Reykjavik, Iceland: a preliminary multi-source analysis

    NASA Astrophysics Data System (ADS)

    Tonini, Roberto; Barsotti, Sara; Sandri, Laura; Tumi Guðmundsson, Magnús

    2015-04-01

    Icelandic volcanism is largely dominated by basaltic magma. Nevertheless the presence of glaciers over many Icelandic volcanic systems results in frequent phreatomagmatic eruptions and associated tephra production, making explosive eruptions the most common type of volcanic activity. Jökulhlaups are commonly considered as major volcanic hazard in Iceland for their high frequency and potentially very devastating local impact. Tephra fallout is also frequent and can impact larger areas. It is driven by the wind direction that can change with both altitude and season, making impossible to predict a priori where the tephra will be deposited during the next eruptions. Most of the volcanic activity in Iceland occurs in the central eastern part, over 100 km to the east of the main population centre around the capital Reykjavík. Therefore, the hazard from tephra fallout in Reykjavík is expected to be smaller than for communities settled near the main volcanic systems. However, within the framework of quantitative hazard and risk analyses, less frequent and/or less intense phenomena should not be neglected, since their risk evaluation depends on the effects suffered by the selected target. This is particularly true if the target is highly vulnerable, as large urban areas or important infrastructures. In this work we present the preliminary analysis aiming to perform a Probabilistic Volcanic Hazard Assessment (PVHA) for tephra fallout focused on the target area which includes the municipality of Reykjavík and the Keflavík international airport. This approach reverts the more common perspective where the hazard analysis is focused on the source (the volcanic system) and it follows a multi-source approach: indeed, the idea is to quantify, homogeneously, the hazard due to the main hazardous volcanoes that could pose a tephra fallout threat for the municipality of Reykjavík and the Keflavík airport. PVHA for each volcanic system is calculated independently and the results

  14. Identification of dominant source of errors in developing streamflow and groundwater projections under near-term climate change

    NASA Astrophysics Data System (ADS)

    Seo, S. B.; Sinha, T.; Mahinthakumar, G.; Sankarasubramanian, A.; Kumar, M.

    2016-07-01

    Uncertainties in projecting the changes in hydroclimatic variables (i.e., temperature and precipitation) under climate change partly arises from the inability of global circulation models (GCMs) in explaining the observed changes in hydrologic variables. Apart from the unexplained changes by GCMs, the process of customizing GCM projections to watershed scale through a model chain—spatial downscaling, temporal disaggregation, and hydrologic model—also introduces errors, thereby limiting the ability to explain the observed changes in hydrologic variability. Toward this, we first propose metrics for quantifying the errors arising from different steps in the model chain in explaining the observed changes in hydrologic variables (streamflow and groundwater). The proposed metrics are then evaluated using a detailed retrospective analyses in projecting the changes in streamflow and groundwater attributes in four target basins that span across a diverse hydroclimatic regimes over the U.S. Sunbelt. Our analyses focused on quantifying the dominant sources of errors in projecting the changes in eight hydrologic variables—mean and variability of seasonal streamflow, mean and variability of 3 day peak seasonal streamflow, mean and variability of 7 day low seasonal streamflow, and mean and standard deviation of groundwater depth—over four target basins using an Penn state Integrated Hydrologic Model (PIHM) between the period 1956-1980 and 1981-2005. Retrospective analyses show that small/humid (large/arid) basins show increased (reduced) uncertainty in projecting the changes in hydrologic attributes. Further, changes in error due to GCMs primarily account for the unexplained changes in mean and variability of seasonal streamflow. On the other hand, the changes in error due to temporal disaggregation and hydrologic model account for the inability to explain the observed changes in mean and variability of seasonal extremes. Thus, the proposed metrics provide insights on

  15. The long-term Swift observations of the high-energy peaked BL Lacertae source 1ES 1959+650

    NASA Astrophysics Data System (ADS)

    Kapanadze, B.; Romano, P.; Vercellone, S.; Kapanadze, S.; Mdzinarishvili, T.; Kharshiladze, G.

    2016-03-01

    We present the results based on the monitoring of the high-energy peaked BL Lacertae object 1ES 1959+650 by the Swift satellite during 2005-2014. Our timing study shows that the source was highly variable on longer (weeks-to-months) time-scales with the 0.3-10 keV fluxes ranging by a factor of 8. It sometimes showed a significant intra-day variability in the course of ˜1 ks, detected mainly in the epochs of higher brightness states. The flux variability exhibited an erratic character and no signatures of periodic variations are revealed. The X-ray spectra were mainly curved with broad ranges of photon index, curvature parameter, hardness ratio, synchrotron spectral energy distribution (SED) peak location which exhibited a significant variability with the flux at different time-scales. Our study of multi-wavelength cross-correlations shows that the one-zone synchrotron self-Compton scenario was not always valid for 1ES 1959+650. The X-ray flares were sometimes not accompanied with an increasing activity in the γ-ray or lower-energy parts of the spectrum and vice versa. Similar to the prominent `orphan' TeV event in 2002, significant flares in the high-energy and very high energy bands in 2009 May and 2012 May were not accompanied by those in the synchrotron part of the spectrum. Similar to other TeV-detected high-energy peaked BLLs, the stochastic acceleration of the electrons from the magnetic turbulence close to the shock front may be more important for our target compared to other scenarios since it showed mainly broader synchrotron SEDs during the X-ray flares expected when the stochastic mechanism is more efficient.

  16. Long-Term Frequency Gradients during Persistent Atrial Fibrillation in Sheep are Associated with Stable Sources in the Left Atrium

    PubMed Central

    Filgueiras-Rama, David; Price, Nicholas F.; Martins, Raphael P.; Yamazaki, Masatoshi; Avula, Uma Mahesh R.; Kaur, Kuljeet; Kalifa, Jérôme; Ennis, Steven R.; Hwang, Elliot; Devabhaktuni, Vijay; Jalife, Jose; Omer Berenfeld, PhD

    2012-01-01

    Background Dominant frequencies (DFs) of activation are higher in the atria of patients with persistent than paroxysmal atrial fibrillation (AF) and left-to-right atrial (LA-to-RA) DF gradients have been identified in both. However, whether such gradients are maintained as long-term persistent AF is established remains unexplored. We aimed at determining in-vivo the time-course in atrial DF values from paroxysmal to persistent AF in sheep, and test the hypothesis that a LA-to-RA DF difference is associated with LA drivers in persistent AF. Methods and Results AF was induced using RA tachypacing (N=8). Electrograms were obtained weekly from a RA lead and a loop recorder (ILR) implanted near the LA. DFs were determined for 5-sec-long electrograms (QRST subtracted) during AF in-vivo and in ex-vivo optical mapping. Underlying structural changes were compared to weight-matched controls (N=4). Following the first AF episode, DF increased gradually over a 2-week period (7±0.21 to 9.92±0.31 Hz, N=6, p<0.05). During 9–24 weeks of AF the DF values on the ILR were higher than the RA (10.6±0.08 vs. 9.3±0.1 Hz, respectively; N=7, p<0.0001). Subsequent optical mapping confirmed a DF gradient from posterior LA-to-RA (9.1±1.0 to 6.9±0.9 Hz. p<0.05) and demonstrated patterns of activation compatible with drifting rotors in the posterior LA (PLA). Persistent AF sheep showed significant enlargement of the PLA compared to controls. Conclusions In the sheep transition from paroxysmal to persistent AF shows continuous LA-to-RA DF gradients in-vivo together with enlargement of the PLA, which harbors the highest frequency domains and patterns of activation compatible with drifting rotors. PMID:23051840

  17. Effective radiology dashboards: key research findings.

    PubMed

    Karami, Mahtab; Safdari, Reza; Rahimi, Azin

    2013-01-01

    Innovative organizations have access to information for business intelligence through the objectives displayed in dashboards. In healthcare organizations, where the goal is to improve quality of care along with reducing costs, the radiology department is important from both financial and clinical aspects. Therefore, how to manage this department has critical impact on the effectiveness and efficiency of the organization. Today, since the information in this department not only has different data structure but also is gathered from different data sources, a well defined, comprehensive dashboard can be an effective tool to enhance performance. PMID:23638580

  18. Filmless radiology at Brooke Army Medical Center

    NASA Astrophysics Data System (ADS)

    Wilson, Dennis L.

    1997-05-01

    The hospital at Brooke Army Medical Center in San Antonio, Texas has an essentially filmless radiology department. Mammography is one of the few services still using film. The radiology department at Brooke takes advantage of a very capable Lockheed Martin PACS to achieve the filmless operation. The old hospital has been replaced by a new hospital, the new Brooke Army Medical Center. As a basis for predictions of activity at new Brooke, the activities at the old Brooke Army Medical Center were examined. The heart of the PACS at Brooke is the image server with an associated database. The image server has the performance required to keep the radiologist from returning to film for diagnosis. A directly connected workstation can present a full screen of images in less than two seconds, even during the busiest hour of the day for this large hospital. In addition the database is used to organize the workflow for the radiology examinations through the hospital. Information about the activity at the new Brooke hospital is used to predict the utilization of the short term storage and the long term storage. In particular, the time that an examination will be retained on the new Brooke short term storage is measured. The Brooke medical complex generates 384.8 exams per day on a typical weekday. The number of exams on a weekend is 40 percent of the exams on the weekday. The storage required is 18.3 gigabytes per day in the short term storage of the Image Storage Unit (ISU) and 9.7 gigabytes per day in the archive. The 256 gigabytes of the ISU will hold 11.7 weeks or about 2.5 months of exams. The archive will hold four years of exams in tow jukeboxes. A working year will have an effective 300 days of equivalent weekday radiology load. By ten years from now the hospital complex can be expected to handle to load that is estimated to be about 160 percent of the current load. With the changes in the storage of disks and archive media that will have occurred by that time, the

  19. Radiology leadership during a disaster event.

    PubMed

    Stockburger, Wayne T; Hill, Randy J; McCormack, Peter C

    2010-01-01

    The trauma of a mass casualty event in Fort Hood, TX very quickly impacted the imaging departments of 3 healthcare facilities in central Texas. In the aftermath,there was an opportunity to reflect and learn. When a mass casualty event or disaster takes place, radiology administration needs to be visible, lead staff, manage media attention and law enforcement presence,all while maintaining a high level of quality patient care. Issues of particular concern are training, coping mechanisms, and the impact of leadership. Military and civilian healthcare facilities have different capabilities in terms of training and operations when it comes to managing such an event. PMID:22279719

  20. The radiation burden of radiological investigations

    PubMed Central

    Mazrani, W; McHugh, K; Marsden, P J

    2007-01-01

    The harmful effects of ionising radiation are widely acknowledged. It has been reported that young children, particularly girls, have a higher sensitivity to radiation than adults. However, the exact detrimental effects of radiation, particularly at the low doses used in routine diagnostic radiography, are unknown and the subject of much controversy. Computed tomography (CT) accounts for about 9% of all radiological examinations but is responsible for 47% of medical radiation dose. Approximately 11% of CT examinations performed are in the paediatric population, but the long‐term hazards of CT are unknown. PMID:18032642