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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. 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.

  4. 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'').

  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

    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

  11. 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

  12. 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

  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, 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...

  8. 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...

  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

    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

  18. 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.

  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. 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.

  15. 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.

  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. 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

  17. 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.

  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. 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

  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. 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.

  16. 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.

  17. 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.

  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. 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.

  12. 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.

  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 interpretation ...

  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 ...

  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. 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)

  10. 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.

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  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. 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

  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. 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.

  12. 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…

  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. 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.

  18. 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

  19. 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.

  20. 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.

  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. 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.

  3. 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.

  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. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  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. 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.

  17. 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

  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. 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.

  9. 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).

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. 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.

  19. 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.

  20. 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.

  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. 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.

  5. 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.

  6. 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)

  7. 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.

  8. 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.

  9. 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.

  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. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  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. 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.