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Methodology for calculating guideline concentrations for safety shot sites

Description: Residual plutonium (Pu), with trace quantities of depleted uranium (DU) or weapons grade uranium (WU), exists in surficial soils at the Nevada Test Site (NTS), Nellis Air Force Range (NAFR), and the Tonopah Test Range (TTR) as the result of the above-ground testing of nuclear weapons and special experiments involving the detonation of plutonium-bearing devices. The special experiments (referred to as safety shots) involving plutonium-bearing devices were conducted to study the behavior of Pu as it was being explosively compressed; ensure that the accidental detonation of the chemical explosive in a production weapon would not result in criticality; evaluate the ability of personnel to manage large-scale Pu dispersal accidents; and develop criteria for transportation and storage of nuclear weapons. These sites do not pose a health threat to either workers or the general public because they are under active institutional control. The DOE is committed to remediating the safety shot sites so that radiation exposure to the public, both now and in the future, will be maintained within the established limits and be as low as reasonably achievable. Remediation requires calculation of a guideline concentration for the Pu, U, and their decay products that are present in the surface soil. This document presents the methodology for calculating guideline concentrations of weapons grade plutonium, weapons grade uranium, and depleted uranium in surface soils at the safety shot sites. Emphasis is placed on obtaining site-specific data for use in calculating dose to potential residents from the residual soil contamination.
Date: June 1, 1997
Partner: UNT Libraries Government Documents Department

Environmental surveillance at Los Alamos during 1994

Description: This report describes environmental monitoring activities at Los Alamos National Laboratory for 1994. Data were collected to assess external penetrating radiation, airborne emissions, liquid effluents, radioactivity of environmental materials and food stuffs, and environmental compliance.
Date: July 1, 1996
Partner: UNT Libraries Government Documents Department

Species for the screening assessment. Columbia River Comprehensive Impact Assessment

Description: Because of past nuclear production operations along the Columbia River, there is intense public and tribal interest in assessing any residual Hanford Site related contamination along the river from the Hanford Reach to the Pacific Ocean. The Columbia River Comprehensive Impact Assessment was proposed to address these concerns. The assessment of the Columbia River is being conducted in phases. The initial phase is a screening assessment of the risk, which addresses current environmental conditions for a range of potential uses. One component of the screening assessment estimates the risk from contaminants in the Columbia River to the environment. The objective of the ecological risk assessment is to determine whether contaminants from the Columbia River pose a significant threat to selected receptor species that exist in the river and riparian communities of the study area. This report (1) identifies the receptor species selected for the screening assessment of ecological risk and (2) describes the selection process. The species selection process consisted of two tiers. In Tier 1, a master species list was developed that included many plant and animal species known to occur in the aquatic and riparian systems of the Columbia River between Priest Rapids Dam and the Columbia River estuary. This master list was reduced to 368 species that occur in the study area (Priest Rapids Dam to McNary Dam). In Tier 2, the 181 Tier 1 species were qualitatively ranked based on a scoring of their potential exposure and sensitivity to contaminants using a conceptual exposure model for the study area.
Date: March 1, 1996
Creator: Becker, J.M.; Brandt, C.A.; Dauble, D.D.; Maughan, A.D. & O`Neil, T.K.
Partner: UNT Libraries Government Documents Department

Application of the RESRAD computer code to VAMP scenario S

Description: The RESRAD computer code developed at Argonne National Laboratory was among 11 models from 11 countries participating in the international Scenario S validation of radiological assessment models with Chernobyl fallout data from southern Finland. The validation test was conducted by the Multiple Pathways Assessment Working Group of the Validation of Environmental Model Predictions (VAMP) program coordinated by the International Atomic Energy Agency. RESRAD was enhanced to provide an output of contaminant concentrations in environmental media and in food products to compare with measured data from southern Finland. Probability distributions for inputs that were judged to be most uncertain were obtained from the literature and from information provided in the scenario description prepared by the Finnish Centre for Radiation and Nuclear Safety. The deterministic version of RESRAD was run repeatedly to generate probability distributions for the required predictions. These predictions were used later to verify the probabilistic RESRAD code. The RESRAD predictions of radionuclide concentrations are compared with measured concentrations in selected food products. The radiological doses predicted by RESRAD are also compared with those estimated by the Finnish Centre for Radiation and Nuclear Safety.
Date: March 1, 1997
Creator: Gnanapragasam, E. K. & Yu, C.
Partner: UNT Libraries Government Documents Department

Extension of UCRL-50936 (13 case studies) as requested by PNE, USAEC

Description: This report provides a reassessment of the Kra Canal Project as prepared in December 1972. This reassessment differs in that thirty- four salvos with a total yield of about 170 MT were assumed; acceptable firing days were selected from actual meteorological data when the winds at all levels up to the expected debris cloud top blew toward the west plus or minus thirty degrees; and the lead in the devices was assumed to be from monazite sand. The doses are considerably less than those estimated in the earlier assessment.
Date: January 29, 1973
Creator: Peterson, K. R.
Partner: UNT Libraries Government Documents Department

Long-term-consequence analysis of no action alternative 2

Description: This report is a supplement to the Waste Isolation Pilot Plant (WIPP) Disposal-Phase Supplemental Environmental Impact Statement. Data and information is described which pertains to estimated impacts from postulated long-term release of radionuclides and hazardous constituents from alpha-bearing wastes stored at major generator/storage sites after loss of institutional control (no action alternative 2). Under this alternative, wastes would remain at the generator sites and not be emplaced at WIPP.
Date: July 1, 1996
Creator: Buck, J.W.; Bagaasen, L.M.; Staven, L.H. & Serne, R.J.
Partner: UNT Libraries Government Documents Department

D & D screening risk evaluation guidance

Description: The Screening Risk Evaluation (SRE) guidance document is a set of guidelines provided for the uniform implementation of SREs performed on decontamination and decommissioning (D&D) facilities. Although this method has been developed for D&D facilities, it can be used for transition (EM-60) facilities as well. The SRE guidance produces screening risk scores reflecting levels of risk through the use of risk ranking indices. Five types of possible risk are calculated from the SRE: current releases, worker exposures, future releases, physical hazards, and criticality. The Current Release Index (CRI) calculates the current risk to human health and the environment, exterior to the building, from ongoing or probable releases within a one-year time period. The Worker Exposure Index (WEI) calculates the current risk to workers, occupants and visitors inside contaminated D&D facilities due to contaminant exposure. The Future Release Index (FRI) calculates the hypothetical risk of future releases of contaminants, after one year, to human health and the environment. The Physical Hazards Index (PHI) calculates the risks to human health due to factors other than that of contaminants. Criticality is approached as a modifying factor to the entire SRE, due to the fact that criticality issues are strictly regulated under DOE. Screening risk results will be tabulated in matrix form, and Total Risk will be calculated (weighted equation) to produce a score on which to base early action recommendations. Other recommendations from the screening risk scores will be made based either on individual index scores or from reweighted Total Risk calculations. All recommendations based on the SRE will be made based on a combination of screening risk scores, decision drivers, and other considerations, as determined on a project-by-project basis.
Date: September 1, 1995
Creator: Robers, S.K.; Golden, K.M. & Wollert, D.A.
Partner: UNT Libraries Government Documents Department

Assessment of activation products in the Savannah River Site environment

Description: This document assesses the impact of radioactive activation products released from SRS facilities since the first reactor became operational late in 1953. The isotopes reported here are those whose release resulted in the highest dose to people living near SRS: {sup 32}P, {sup 51}Cr, {sup 60}C, and {sup 65}Zn. Release pathways, emission control features, and annual releases to the aqueous and atmospheric environments are discussed. No single incident has resulted in a major acute release of activation products to the environment. The releases were the result of normal operations of the reactors and separations facilities. Releases declined over the years as better controls were established and production was reduced. The overall radiological impact of SRS activation product atmospheric releases from 1954 through 1994 on the offsite maximally exposed individual can be characterized by a total dose of 0.76 mrem. During the same period, such an individual received a total dose of 14,400 mrem from non-SRS sources of ionizing radiation present in the environment. SRS activation product aqueous releases between 1954 and 1994 resulted in a total dose of 54 mrem to the offsite maximally exposed individual. The impact of SRS activation product releases on offsite populations also has been evaluated.
Date: July 1, 1996
Creator: Carlton, W.H. & Denham, M.
Partner: UNT Libraries Government Documents Department

Development of a building sump database for the Y-12 Plant, Oak Ridge, Tennessee

Description: Operations at the Oak Ridge Y-12 Plant have resulted in contamination of Upper East Fork Poplar Creek (UEFPC) and shallow groundwater through soil erosion, infiltration, and outfall discharges. The contamination of groundwater has been documented for nearly two decades, largely through well monitoring efforts. This study represents the first effort to formally identify and compile location data on sumps at the Y-12 Plant, several of which are known or are suspected to pump groundwater. Operation of several of these sumps have been documented to affect groundwater hydraulics and contaminant pathways. This report presents preliminary results of an investigation attempting to identify sources of data on building sumps that have not previously been incorporated into existing Y-12 Plant groundwater databases. This investigation involved acquiring information on building sumps, such as location, building number, water source, discharge location, and availability of analytical data. This information was used to construct an ARC/INFO database capable of simultaneously storing spatial data on sump locations and attribute information concerning the operation of individual building sumps. This database will be referred to hereafter as the Y-12 Plant Building Sump Database.
Date: July 1, 1997
Creator: Sepanski, R.J. & Field, S.M.
Partner: UNT Libraries Government Documents Department

Code manual for MACCS2: Volume 1, user`s guide

Description: This report describes the use of the MACCS2 code. The document is primarily a user`s guide, though some model description information is included. MACCS2 represents a major enhancement of its predecessor MACCS, the MELCOR Accident Consequence Code System. MACCS, distributed by government code centers since 1990, was developed to evaluate the impacts of severe accidents at nuclear power plants on the surrounding public. The principal phenomena considered are atmospheric transport and deposition under time-variant meteorology, short- and long-term mitigative actions and exposure pathways, deterministic and stochastic health effects, and economic costs. No other U.S. code that is publicly available at present offers all these capabilities. MACCS2 was developed as a general-purpose tool applicable to diverse reactor and nonreactor facilities licensed by the Nuclear Regulatory Commission or operated by the Department of Energy or the Department of Defense. The MACCS2 package includes three primary enhancements: (1) a more flexible emergency-response model, (2) an expanded library of radionuclides, and (3) a semidynamic food-chain model. Other improvements are in the areas of phenomenological modeling and new output options. Initial installation of the code, written in FORTRAN 77, requires a 486 or higher IBM-compatible PC with 8 MB of RAM.
Date: March 1, 1997
Creator: Chanin, D.I. & Young, M.L.
Partner: UNT Libraries Government Documents Department

Radiological dose assessment for the decontaminated concrete removed from 183-H solar evaporation basins at the Hanford site, Richland, Washington

Description: Potential maximum radiation dose rates over a 1,000-year time horizon were calculated for exposure to the decontaminated concrete removed from the 183-H Solar Evaporation Basins at the Hanford Site, Richland, Washington. The RESRAD computer code, Version 5.62, which implements the methodology described in the US Department of Energy`s manual for developing residual radioactive material guidelines, was used in this evaluation. Currently, the concrete is not being used. Four potential exposure scenarios were developed for the land area where the decontaminated concrete will be stored. In Scenario A industrial use of the land is assumed; in Scenario B recreational use of the land is assumed; in Scenario C residential use of the land is assumed; and in Scenario D (a plausible but unlikely land-use scenario), the presence of a subsistence farmer in the immediate vicinity of the land is assumed. For Scenarios A and B, water used for drinking is assumed to be surface water from the Columbia River; for Scenarios C and D, groundwater drawn from a well located at the downgradient edge of the storage area is the only source of water for drinking, irrigation, and raising livestock. Conservative parameters values were used to estimate the radiation doses. The results of the evaluation indicate that the US Department of Energy`s dose limit of 100 mrem/yr would not be exceeded for any of the scenarios analyzed. The potential maximum dose rates for Scenarios A, B, C, and D are 0.75, 0.022, 29, 29 mrem/yr, respectively. An uncertainty analysis was performed to determine which parameters have the greatest impact on the estimated doses. The doses in Scenarios C and D were found to be very sensitive to the magnitude of the irrigation rate.
Date: January 1, 1997
Creator: Kamboj, S.; Faillace, E. & Yu, C.
Partner: UNT Libraries Government Documents Department

Isotopic signatures by bulk analyses

Description: Los Alamos National Laboratory has developed a series of measurement techniques for identification of nuclear signatures by analyzing bulk samples. Two specific applications for isotopic fingerprinting to identify the origin of anthropogenic radioactivity in bulk samples are presented. The first example is the analyses of environmental samples collected in the US Arctic to determine the impact of dumping of radionuclides in this polar region. Analyses of sediment and biota samples indicate that for the areas sampled the anthropogenic radionuclide content of sediments was predominantly the result of the deposition of global fallout. The anthropogenic radionuclide concentrations in fish, birds and mammals were very low. It can be surmised that marine food chains are presently not significantly affected. The second example is isotopic fingerprinting of water and sediment samples from the Rocky Flats Facility (RFP). The largest source of anthropogenic radioactivity presently affecting surface-waters at RFP is the sediments that are currently residing in the holding ponds. One gram of sediment from a holding pond contains approximately 50 times more plutonium than 1 liter of water from the pond. Essentially 100% of the uranium in Ponds A-1 and A-2 originated as depleted uranium. The largest source of radioactivity in the terminal Ponds A-4, B-5 and C-2 was naturally occurring uranium and its decay product radium. The uranium concentrations in the waters collected from the terminal ponds contained 0.05% or less of the interim standard calculated derived concentration guide for uranium in waters available to the public. All of the radioactivity observed in soil, sediment and water samples collected at RFP was naturally occurring, the result of processes at RFP or the result of global fallout. No extraneous anthropogenic alpha, beta or gamma activities were detected. The plutonium concentrations in Pond C-2 appear to vary seasonally.
Date: December 1, 1997
Creator: Efurd, D.W. & Rokop, D.J.
Partner: UNT Libraries Government Documents Department

Portsmouth Gaseous Diffusion Plant annual site environmental report for 1993

Description: This calendar year (CY) 1993 annual report on environmental monitoring of the US Department of Energy`s (DOE`s) Portsmouth Gaseous Diffusion Plant (Portsmouth) and its environs consists of three separate documents: a summary pamphlet for the general public; a more detail discussion and of compliance status, data, and environmental impacts (this document); and a volume of detailed data that is available on request. The objectives of this report are to report compliance status during 1993; provide information about the plant site and plant operations; report 1993 monitoring data for the installation and its environs that may have been affected by operations on the plant site; document information on input and assumptions used in calculations; provide trend analyses (where appropriate) to indicate increases and decreases in environmental impact, and provide general information on quality assurance for the environmental monitoring program.
Date: November 1, 1994
Creator: Horak, C.M.
Partner: UNT Libraries Government Documents Department

Radionuclide concentrations in soils and produce from Cochiti, Jemez, Taos, and San Ildefonso Pueblo Gardens

Description: Radionuclide ({sup 3}H, {sup 90}Sr, {sup 137}Cs, {sup 238}Pu, {sup 239}Pu, and total uranium) concentrations were determined in soils and produce collected from Cochiti, Jemez, Taos, and San Ildefonso Pueblo gardens. All radionuclides in soils from Pueblo areas were within or just above regional statistical (natural and/or worldwide fallout) reference levels. Similarily, the average levels of radionuclides in produce collected from Cochiti, Jemez, Taos, and San Ildefonso Pueblo gardens were not significantly different in produce collected from regional (background) locations. The effective (radiation) dose equivalent from consuming 352 lb of produce from Cochiti, Jemez, Taos, and San Ildefonso, after natural background has been subtracted, was 0.036 ({+-}0.016), 0.072 ({+-}0.051), 0.012 ({+-}0.027), and 0.110 ({+-}0.102) mrem/yr, respectively. The highest calculated dose, based on the mean + 2 std dev (95% confidence level), was 0.314 mrem/yr; this was <0.4% of the International Commission on Radiological Protection permissible dose limit for protecting members of the public.
Date: May 1, 1995
Creator: Fresquez, P.R.; Armstrong, D.R. & Salazar, J.G.
Partner: UNT Libraries Government Documents Department

Computed isotopic inventory and dose assessment for SRS fuel and target assemblies

Description: Past studies have identified and evaluated important radionuclide contributors to dose from reprocessed spent fuel sent to waste for Mark 16B and 22 fuel assemblies and for Mark 31 A and 31B target assemblies. Fission-product distributions after a 5- and 15-year decay time were calculated for a ``representative`` set of irradiation conditions (i.e., reactor power, irradiation time, and exposure) for each type of assembly. The numerical calculations were performed using the SHIELD/GLASS system of codes. The sludge and supernate source terms for dose were studied separately with the significant radionuclide contributors for each identified and evaluated. Dose analysis considered both inhalation and ingestion pathways: The inhalation pathway was analyzed for both evaporative and volatile releases. Analysis of evaporative releases utilized release fractions for the individual radionuclides as defined in the ICRP-30 by DOE guidance. A release fraction of unity was assumed for each radionuclide under volatile-type releases, which would encompass internally initiated events (e.g., fires, explosions), process-initiated events, and externally initiated events. Radionuclides which contributed at least 1% to the overall dose were designated as significant contributors. The present analysis extends and complements the past analyses through considering a broader spectrum of fuel types and a wider range of irradiation conditions. The results provide for a more thorough understanding of the influences of fuel composition and irradiation parameters on fission product distributions (at 2 years or more). Additionally, the present work allows for a more comprehensive evaluation of radionuclide contributions to dose and an estimation of the variability in the radionuclide composition of the dose source term that results from the spent fuel sent to waste encompassing a broad spectrum of fuel compositions and irradiation conditions.
Date: June 19, 1995
Creator: Chandler, M.C.; Ketusky, E.T. & Thoman, D.C.
Partner: UNT Libraries Government Documents Department

An exposure assessment of radionuclide emissions associated with potential mixed-low level waste disposal facilities at fifteen DOE sites

Description: A screening method was developed to compare the doses received via the atmospheric pathway at 15 potential DOE MLLW (mixed low-level waste) sites. Permissible waste concentrations were back calculated using the radioactivity NESHAP (National Emissions Standards for Hazardous Air Pollutants) in 40 FR 61 (DOE Order 5820.2A performance objective). Site-specific soil and meteorological data were used to determine permissible waste concentrations (PORK). For a particular radionuclide, perks for each site do not vary by more than one order of magnitude. perks of {sup 14}C are about six orders of magnitude more restrictive than perks of {sup 3}H because of differences in liquid/vapor partitioning, decay, and exposure dose. When comparing results from the atmospheric pathway to the water and intruder pathways, {sup 14}C disposal concentrations were limited by the atmospheric pathway for most arid sites; for {sup 3}H, the atmospheric pathway was not limiting at any of the sites. Results of this performance evaluation process are to be used for planning for siting of disposal facilities.
Date: May 1, 1996
Creator: Lombardi, D.A. & Socolof, M.L.
Partner: UNT Libraries Government Documents Department

Focused feasibility study for surface soil at the main pits and pushout area, J-field toxic burning pits area, Aberdeen Proving Ground, Maryland

Description: The Environmental Management Division of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). J-Field is located within the Edgewood Area of APG in Harford County, Maryland. Since World War II, activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning/open detonation. Portions of J-Field continue to be used for the detonation and disposal of unexploded ordnance (UXO) by open burning/open detonation under authority of the Resource Conservation and Recovery Act.
Date: June 1, 1996
Creator: Patton, T.; Benioff, P.; Biang, C. & Butler, J.
Partner: UNT Libraries Government Documents Department

RESRAD-ECORISK: A computer code for ecological risk assessment

Description: RESRAD-ECORISK is a PC-based computer code developed by Argonne National Laboratory (ANL) to estimate risks from exposure of ecological receptors at sites contaminated with potentially hazardous chemicals. The code is based on and is consistent with the methodologies of RESRAD-CHEM, an ANL-developed computer code for assessments of human health risk. RESRAD-ECORISK uses environmental fate and transport models to estimate contaminant concentrations in environmental media from an initial contaminated soil source and food-web uptake models to estimate contaminant doses to ecological receptors. The dose estimates are then used to estimate a risk for the ecological receptor and to calculate preliminary soil guidelines for reducing risks to acceptable levels. Specifically, RESRAD-ECORISK calculates (1) a species-specific applied daily dose for each contaminant (using species-specific life history information and site-specific environmental media concentrations), (2) an ecological hazard quotient (EHQ) for each contaminant and species, and (3) preliminary soil cleanup criteria for each contaminant and receptor. RESRAD-ECORISK incorporates a user-friendly menu-driven interface, databases and default values for a variety of ecological and chemical parameters, and on-line help for easy operation. The code is sufficiently flexible to simulate different contaminated sites and incorporate site-specific ecological data.
Date: December 1, 1995
Creator: Cheng, J.J.
Partner: UNT Libraries Government Documents Department

Derivation of guidelines for uranium residual radioactive material in soil at the former Baker Brothers, Inc., Site, Toledo, Ohio

Description: Residual radioactive material guidelines for uranium in soil were derived for the former Baker Brothers, Inc., site in Toledo, Ohio. This site has been identified for remedial action under the U.S. Department of Energy`s (DOE`s) Formerly Utilized Sites Remedial Action Program (FUSRAP). Single-nuclide and total-uranium guidelines were derived on the basis of the requirement that following remedial action, the 50-year committed effective dose equivalent to a hypothetical individual living or working in the immediate vicinity of the site should not exceed a dose constraint of 30 mrem/yr for the current use and likely future use scenarios or a dose limit of 100 mrem/yr for less likely future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation; RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines. Three scenarios were considered; each assumed that for a period of 1,000 years following remedial action, the site would be used without radiological restrictions. The three scenarios varied with regard to the type of site use, time spent at the site by the exposed individual, and sources of food and water consumed. The evaluation indicates that the dose constraint of 30 mrem/yr would not be exceeded for uranium (including uranium-234, uranium-235, and uranium-238) within 1,000 years, provided that the soil concentration of total combined uranium (uranium-234, uranium-235, and uranium-238) at the former Baker Brothers site did not exceed 710 pCi/g for Scenario A (industrial worker, current use) or 210 pCi/g for Scenario B (resident - municipal water supply, a likely future use). The dose limit of 100 mrem/yr would not be exceeded at the site if the total uranium concentration of the soil did not exceed 500 pCi/g for Scenario C (subsistence farmer - on-site well water, a plausible but unlikely future ...
Date: April 1, 1995
Creator: Nimmagadda, M.; Kamboj, S. & Yu, C.
Partner: UNT Libraries Government Documents Department

Applying RESRAD-CHEM for chemical risk assessment

Description: RESRAD-CHEM is a multiple pathway analysis computer code to evaluate chemically contaminated sites; it was developed at Argonne National Laboratory for the US Department of Energy. The code is designed to predict human health risks from exposure to hazardous chemicals and to derive cleanup criteria for chemically contaminated soils. It consists of environmental fate and transport models and is capable of predicting chemical concentrations over time in different environmental media. The methodology used in RESRAD-CHEM for exposure assessment and risk characterization follows the US Environmental Protection Agency`s guidance on Human Health Evaluation for Superfund. A user-friendly interface is incorporated for entering data, operating the code, and displaying results. RESRAD-CHEM is easy to use and is a powerful tool to assess chemical risk from environmental exposure.
Date: July 1, 1995
Creator: Cheng, J.J. & Yu, C.
Partner: UNT Libraries Government Documents Department

Hanford Site Long-term Surface Barrier Development Program: Fiscal year 1994 highlights

Description: The Hanford Site Surface Barrier Development Program was organized in 1985 to test the effectiveness of various barrier designs in minimizing the effects of water infiltration; plant, animal and human intrusion; and wind and water erosion on buried wastes, plus preventing or minimizing the emanation of noxious gases. A team of scientists from the Pacific Northwest Laboratory (PNL) and engineers from Westinghouse Hanford Company (WHC) direct the barrier development effort. ICF Kaiser Hanford Company, in conjunction with WHC and PNL, developed design drawings and construction specifications for a 5-acre prototype barrier. The highlight of efforts in FY 1994 was the construction of the prototype barrier. The prototype barrier was constructed on the Hanford Site at the 200 BP-1 Operable Unit of the 200 East Area. Construction was completed in August 1994 and monitoring instruments are being installed so experiments on the prototype barrier can begin in FY 1995. The purpose of the prototype barrier is to provide insights and experience with issues regarding barrier design, construction, and performance that have not been possible with individual tests and experiments conducted to date. Additional knowledge and experience was gained in FY 1994 on erosion control, physical stability, water infiltration control, model testing, Resource Conservation and Recovery Act (RCRA) comparisons, biointrusion control, long-term performance, and technology transfer.
Date: August 1, 1995
Creator: Petersen, K. L.; Link, S. O. & Gee, G. W.
Partner: UNT Libraries Government Documents Department

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

Description: This paper describes a multilaboratory research program that is directed toward addressing many questions that analysts face when performing air cleaning accident consequence assessments. The program involves developing analytical tools and supportive experimental data that will be useful in making more realistic assessments of accident source terms within and up to the atmospheric boundaries of nuclear fuel cycle facilities. The types of accidents considered in this study includes fires, explosions, spills, tornadoes, criticalities, and equipment failures. The main focus of the program is developing an accident analysis handbook (AAH). We will describe the contents of the AAH, which include descriptions of selected nuclear fuel cycle facilities, process unit operations, source-term development, and accident consequence analyses. Three computer codes designed to predict gas and material propagation through facility air cleaning systems are described. These computer codes address accidents involving fires (FIRAC), explosions (EXPAC), and tornadoes (TORAC). The handbook relies on many illustrative examples to show the analyst how to approach accident consequence assessments. We will use the FIRAC code and a hypothetical fire scenario to illustrate the accident analysis capability.
Date: January 1, 1982
Creator: Andrae, R.W.; Bolstad, J.W. & Gregory, W.S.
Partner: UNT Libraries Government Documents Department

Parameter uncertainty and model predictions: a review of Monte Carlo results

Description: Studies of parameter variability by Monte Carlo analysis are reviewed using repeated simulations of the model with randomly selected parameter values. At the beginning of each simulation, parameter values are chosen from specific frequency distributions. This process is continued for a number of iterations sufficient to converge on an estimate of the frequency distribution of the output variables. The purpose was to explore the general properties of error propagaton in models. Testing the implicit assumptions of analytical methods and pointing out counter-intuitive results produced by the Monte Carlo approach are additional points covered.
Date: January 1, 1979
Creator: Gardner, R.H. & O'Neill, R.V.
Partner: UNT Libraries Government Documents Department