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Summary of MATHEW/ADPIC model evaluation studies

Description: This report summarizes model evaluation studies conducted for the MATHEW/ADPIC transport and diffusion models during the past ten years. These models support the US Department of Energy Atmospheric Release Advisory Capability, an emergency response service for atmospheric releases of nuclear material. Field campaigns involving tracer releases used in these studies cover a broad range of meteorology, terrain and tracer release heights, the three most important aspects of estimating air concentration values resulting from airborne releases of toxic material. Results of these studies show that these models can estimate air concentration values within a factor of 2, 20% to 50% of the time and a factor of 5, 40% to 80% of the time. As the meteorology and terrain become more complex and the release height of the tracer is increased the accuracy of the model calculations degrades. This band of uncertainty appears to correctly represent the capability of these models at this time. 13 refs., 8 figs.
Date: October 1, 1985
Creator: Dickerson, M.H.
Partner: UNT Libraries Government Documents Department

Generating color terrain images in an emergency response system

Description: The Atmospheric Release Advisory Capability (ARAC) provides real-time assessments of the consequences resulting from an atmospheric release of radioactive material. In support of this operation, a system has been created which integrates numerical models, data acquisition systems, data analysis techniques, and professional staff. Of particular importance is the rapid generation of graphical images of the terrain surface in the vicinity of the accident site. A terrain data base and an associated acquisition system have been developed that provide the required terrain data. This data is then used as input to a collection of graphics programs which create and display realistic color images of the terrain. The graphics system currently has the capability of generating color shaded relief images from both overhead and perspective viewpoints within minutes. These images serve to quickly familiarize ARAC assessors with the terrain near the release location, and thus permit them to make better informed decisions in modeling the behavior of the released material. 7 refs., 8 figs.
Date: August 1, 1985
Creator: Belles, R.D.
Partner: UNT Libraries Government Documents Department

MESOI Version 2. 0: an interactive mesoscale Lagrangian puff dispersion model with deposition and decay

Description: MESOI Version 2.0 is an interactive Lagrangian puff model for estimating the transport, diffusion, deposition and decay of effluents released to the atmosphere. The model is capable of treating simultaneous releases from as many as four release points, which may be elevated or at ground-level. The puffs are advected by a horizontal wind field that is defined in three dimensions. The wind field may be adjusted for expected topographic effects. The concentration distribution within the puffs is initially assumed to be Gaussian in the horizontal and vertical. However, the vertical concentration distribution is modified by assuming reflection at the ground and the top of the atmospheric mixing layer. Material is deposited on the surface using a source depletion, dry deposition model and a washout coefficient model. The model also treats the decay of a primary effluent species and the ingrowth and decay of a single daughter species using a first order decay process. This report is divided into two parts. The first part discusses the theoretical and mathematical bases upon which MESOI Version 2.0 is based. The second part contains the MESOI computer code. The programs were written in the ANSI standard FORTRAN 77 and were developed on a VAX 11/780 computer. 43 references, 14 figures, 13 tables.
Date: November 1, 1983
Creator: Ramsdell, J.V.; Athey, G.F. & Glantz, C.S.
Partner: UNT Libraries Government Documents Department

Lower limit of detection: definition and elaboration of a proposed position for radiological effluent and environmental measurements

Description: A manual is provided to define and illustrate a proposed use of the Lower Limit of Detection (LLD) for Radiological Effluent and Environmental Measurements. The manual contains a review of information regarding LLD practices gained from site visits; a review of the literature and a summary of basic principles underlying the concept of detection in Nuclear and Analytical Chemistry; a detailed presentation of the application of LLD principles to a range of problem categories (simple counting to multinuclide spectroscopy), including derivations, equations, and numerical examples; and a brief examination of related issues such as reference samples, numerical quality control, and instrumental limitations. An appendix contains a summary of notation and terminology, a bibliography, and worked-out examples. 100 references, 10 figures, 7 tables.
Date: September 1, 1984
Creator: Currie, L.A.
Partner: UNT Libraries Government Documents Department

Laboratory research on tailings stabilization methods and their effectiveness in radiation containment. [Uranium, reduction of radon exhalation]

Description: This report describes a study of various methods, techniques, and materials for stabilizing uranium mill tailings to reduce radon exhalation. Radon emanation from tailings particles, radon exhalation from tailings, and methods that could be used to reduce radon exhalation from tailings piles are discussed. Surface radon flux and soil gas concentrations were measured in experiment chambers or columns consisting of uranium tailings and various types and thicknesses of cover materials. The applicability of diffusion theory was examined and effective diffusion coefficients were determined for clay, soil, and sand. The variation of radon flux with atmospheric effects and moisture also was investigated. The effectiveness of several types of chemical stabilizers for both volumetric and surface application in reducing radon exhalation is reported. Some volumetric stabilizers reduced radon flux by 90 percent or more. Radon flux was determined through the use of charcoal gas mask canisters, and flux accumulation chambers sampled by Lucas cells. Both of these techniques are described. Soil gas concentration was sampled with Lucas cells and counted with a sodium iodide scintillation spectrometer system. Emanating power of uranium tailings was measured for several particle sizes and found to be relatively constant at about 20 percent. Two types of grasses were found that would grow in tailings if sufficient water and fertilizer were provided. The effect of vegetation on radon exhalation was not determined.
Date: April 1, 1978
Creator: Macbeth, P.J.; Jensen, C.M.; Rogers, V.C. & Overmyer, R.F.
Partner: UNT Libraries Government Documents Department

Computer code to assess accidental pollutant releases

Description: A computer code was developed to calculate the cumulative frequency distributions of relative concentrations of an air pollutant following an accidental release from a stack or from a building penetration such as a vent. The calculations of relative concentration are based on the Gaussian plume equations. The meteorological data used for the calculation are in the form of joint frequency distributions of wind and atmospheric stability.
Date: July 1, 1980
Creator: Pendergast, M.M. & Huang, J.C.
Partner: UNT Libraries Government Documents Department

ARAC: a centralized computer assisted emergency planning, response, and assessment system for atmospheric releases of toxic material

Description: The Atmospheric Release Advisory Capability (ARAC) is an emergency planning, response, and assessment service, developed by the US Departments of Energy and Defense, and focused, thus far, on atmospheric releases of nuclear material. For the past 14 years ARAC has responded to over 150 accidents, potential accidents, and major exercises. The most notable accident responses are the COSMOS 954 reentry, the Three Mile Island (TMI-2) accident and subsequent purge of /sup 85/Kr from the containment vessel, the recent UF/sub 6/ accident at the Kerr-McGee Plant, Gore, Oklahoma, and the Chernobyl nuclear reactor accident in the Soviet Union. Based on experience in the area of emergency response, developed during the past 14 years, this paper describes the cost effectiveness and other advantages of a centralized emergency planning, response, and assessment service for atmospheric releases of nuclear material.
Date: October 1, 1986
Creator: Dickerson, M.H. & Knox, J.B.
Partner: UNT Libraries Government Documents Department

RETADDII: modeling long-range atmospheric transport of radionuclides

Description: A versatile model is described which estimates atmospheric dispersion based on plume trajectories calculated for the mixed layer. This model allows the treatment of the dispersal from a source at an arbitrary height while taking account of plume depletion by dry and wet deposition together with the decay of material to successor species. The plume depletion, decay and growth equations are solved in an efficient manner which can accommodate up to eight pollutants (i.e. a parent and seven serial decay products). The code is particularly suitable for applications involving radioactive chain decay or for cases involving chemical species with successor decay products. Arbitrary emission rates can be specified for the members of the chain or, as is commonly the case, a sole emission rate can be specified for the first member. The code, in its current configuration, uses readily available upper-air wind data for the North American continent.
Date: January 1, 1982
Creator: Murphy, B.D.
Partner: UNT Libraries Government Documents Department

Improved capabilities for area environmental monitoring at Oak Ridge National Laboratory

Description: Recent increased concern for environmental safety hazards resulting from releases of radioactivity and other hazardous materials have necessitated the installation of improved monitoring instruments and methods at Oak Ridge National Laboratory (ORNL). Over the past several years a number of important instrument projects have been initiated to improve plant monitoring systems (both inside the Laboratory and in adjacent East Tennessee areas) and to enhance operational capabilities for detecting releases of hazardous and/or radioactive materials. These measures will significantly modernize and increase the number of monitoring stations measuring activity levels in (1) plant effluent gases, (2) plant effluent liquid wastes, and (3) local streams and rivers. Monitoring instruments within the operating buildings of the Laboratory are being upgraded, and three instrumented meteorological towers are in service to provide information for calculating deposition patterns over surrounding areas. Advanced, on-line central data collection systems supply continuous information for programmable alarm-level circuits, for display at remote terminals throughout ORNL, and for scientific long-term data base purposes. When these improvements are completed in about two years, the number of environmentally derived signals will significantly exceed 750 monitored values.
Date: January 1, 1986
Creator: Morris, A.C. Jr.; Bauer, M.L. & Pudelek, R.E.
Partner: UNT Libraries Government Documents Department

Validation of Turner Workbook normalized air exposure predictions for surface level releases using Hanford dispersion data. [R]

Description: In general, the methods used to determine atmospheric stability in assessment models depend upon the personal needs of the assessor. However, the results of this study indicate that for conditions similar to those prevailing during the Hanford tests and for the assumptions used with the Turner Workbook calculations, a method of atmospheric stability determination based on the vertical temperature gradient should be used if the assessor desires to insure some conservatism in his calculations of Eu/Q. On the other hand, a more realistic estimate of Eu/Q can be obtained using a method based on sigma/sub theta/, recognizing that a tendency still exists to overpredict Eu/Q. An additional approach to improve model predictions would be to apply the linear regression parameters shown in Table 4 to predictions based on the vertical temperature gradient methods. Application of the regression parameters to adjust the predictions is feasible because of the relatively high correlation between measured and predicted value exhibited by all three methods of stability determination.
Date: January 1, 1979
Creator: Miller, C.W.; Little, C.A. & Hoffman, F.O.
Partner: UNT Libraries Government Documents Department

Real time quality control of meteorological data used in SRP's emergency response system

Description: The Savannah River Laboratory's WIND minicomputer system allows quick and accurate assessment of an accidental release at the Savannah River Plant using data from eight meteorological towers. The accuracy of the assessment is largely determined by the accuracy of the meteorological data; therefore quality control is important in an emergency response system. Real-time quality control of this data will be added to the WIND system to automatically identify inaccurate data. Currently, the system averages the measurements from the towers to minimize the influence of inaccurate data being used in calculations. The computer code used in the real-time quality control has been previously used to identify inaccurate measurements from the archived tower data.
Date: May 1, 1980
Creator: Pendergast, M.M.
Partner: UNT Libraries Government Documents Department

CRRIS: a methodology for assessing the impact of airborne radionuclide releases

Description: The Computerized Radiological Risk Investigation System (CRRIS) consists of six fully integrated computer codes which calculate environmental transport and resulting doses and risks to individuals or populations exposed to atmospheric radionuclide releases. The individual codes may be used alone for various assessment applications or may be run as a system. This presentation provides an overview and introduction to this system of computer codes and their use in conducting nuclear assessments. Radionuclides are handled by CRRIS either in terms of the released radionuclides or in terms of exposure radionuclides which consist of both the released nuclides and all (or a subset of) the decay daughters that grow in during environmental transport. The capability of CRRIS to handle radionuclide chains is accomplished through PRIMUS which serves as a preprocessor by accessing a library of radionuclide decay data and sets up matricies of decay constants which are used by the other CRRIS codes in all calculations involving transport and decay. PRIMUS may also be run independently by the user to define the decay chains, radionuclide decay constants, and branching ratios.
Date: January 1, 1983
Creator: Baes, C.F. III & Miller, C.W.
Partner: UNT Libraries Government Documents Department

Optimization aspects of the ARAC real-time radiological emergency response system

Description: The Atmospheric Release Advisory Capability (ARAC) project at the Lawrence Livermore National Laboratory responds to radiological emergencies throughout the Continental United States. Using complex three-dimensional dispersion models to account for the effects of complex meteorology and regional terrain, ARAC simulates the release of radioactive materials and provides dispersion, deposition, and dose calculations that are displayed over local geographic features for use by authorities at the accident/release site. ARAC's response is ensured by a software system that (1) makes optimal use of dispersion models, (2) minimizes the time required to provide projections, and (3) maximizes the fault-tolerance of the system. In this paper we describe ARAC's goals and functionality and the costs associated with its development and use. Specifically, we address optimizations in ARAC notifications, meteorological data collection, the determination of site- and problem-specific parameters, the generation of site-specific topography and geography, the running of models, and the distribution of ARAC products. We also discuss the backup features employed to ensure ARAC's ability to respond.
Date: July 1, 1985
Creator: Taylor, S.S. & Sullivan, T.J.
Partner: UNT Libraries Government Documents Department

Radioactivity in gaseous waste discharged from the separations facilities during fourth quarter of 1979

Description: This document is issued quarterly for the purpose of summarizing the radioactive gaseous wastes that are discharged from the facilities of the Rockwell Hanford Operations (Rockwell). Data on alpha and beta emissions during 1979 are presented where relevant to the gaseous effluent. Emission data are not included on gaseous wastes produced within the 200 areas by other Hanford contractors.
Date: February 22, 1980
Creator: Sliger, G. J.
Partner: UNT Libraries Government Documents Department

Diffusion rates for elevated releases

Description: A search of the literature related to diffusion from elevated sources has determined that an adequate data base exists for use in developing parameterizations for estimating diffusion rates for material released from free standing stacks at nuclear power plants. A review of published data analyses indicates that a new parameterization of horizontal diffusion rates specifically for elevated releases is not likely to significantly change the magnitudes of horizontal diffusion coefficients on the average. However, the uncertainties associated with horizontal diffusion coefficient estimates under any given set of atmospheric conditions could be reduced by a new parameterization. Similarly, a new parameterization of vertical diffusion rates would be unlikely to significantly alter the magnitudes of diffusion coefficients for unstable atmospheric conditons. However, for neutral and stable atmospheric conditions, a new parameterization of vertical diffusion rates might increase vertical diffusion coefficients significantly. The increase would move ground-level time-integrated concentration maxima closer to the plant and would increase the maxima. 55 references, 2 figures, 4 tables.
Date: November 1, 1983
Creator: Ramsdell, J.V.
Partner: UNT Libraries Government Documents Department

Background information on sources of low-level radionuclide emissions to air

Description: This report provides a general description and reported emissions for eight low-level radioactive source categories, including facilties that are licensed by the Nuclear Regulatory Commission (NRC) and Agreement States, and non-Department of Energy (DOE) federal facilities. The eight categories of low-level radioactive source facilities covered by this report are: research and test reactors, accelerators, the radiopharmaceutical industry, source manufacturers, medical facilities, laboratories, naval shipyards, and low-level commercial waste disposal sites. Under each category five elements are addressed: a general description, a facility and process description, the emission control systems, a site description, and the radionuclides released to air (from routine operations).
Date: September 1, 1983
Creator: Corbit, C.D.; Herrington, W.N.; Higby, D.P.; Stout, L.A. & Corley, J.P.
Partner: UNT Libraries Government Documents Department

Evaluation of the Split-H approach to modeling non-buoyant releases from vent stacks

Description: Position C.2.b of Regulatory Guide 1.111 describes an approach to modeling the diffusion of effluents from roof top vents and short stacks using an elevated plume model under some conditions and using a ground-level source building wake model under other conditions. The approach is sometimes called a Split-H model. This report presents the results of an evaluation of the technical basis for and utility of the concept behind the Split-H model, outlines the devlopment of an upgraded model with those estimated using the Regulatory Guide Split-H model and a ground-level building wake model, and discusses alternatives to the Regulatory Guide position that the NRC may wish to consider. Concentration comparisons are made using model results for meteorological data from 18 nuclear power plant sites.
Date: April 1, 1983
Creator: Ramsdell, J.V.
Partner: UNT Libraries Government Documents Department

Atmospheric Release Advisory Capability (ARAC): update 1977. [Atmospheric monitoring of effluents from DOE nuclear facilities]

Description: The Atmospheric Release Advisory Capability (ARAC) is a service to facilities requiring a means of realtime prediction of the extent of health hazards that may result from a release of radionuclides or other toxic materials. The ARAC system, sponsored by the Department of Energy (DOE), consists of a network of serviced facilities and a central facility at the University of California, Lawrence Livermore Laboratory (LLL). Since 1973, when the concept was initiated, a joint feasibility study of the ARAC system has been conducted by LLL and the Savannah River Laboratory (SRL) and research and development was initiated to implement this service for DOE nuclear facilities. The present system of three sites (LLL, Savannah River Plant and the Rocky Flats Plant) is now being tested and evaluated with the Mound Laboratory scheduled to join the network in the fall of 1977. Plans are presently being formulated to implement the ARAC service for additional DOE sites during the next several years. This article briefly describes the ARAC concept, discusses progress to date and outlines future plans for completing the system's development and operating the service.
Date: October 1, 1977
Creator: Dickerson, M.H.
Partner: UNT Libraries Government Documents Department

Filter testing and development for prolonged transuranic service and waste reduction

Description: The life of High Efficiency Particulate Air (HEPA) filters used in transuranic service is influenced greatly by the gaseous and particulate matter to which the filters are exposed. The most severe conditions encountered at Rocky Flats are at the ventilation systems serving the plutonium recovery operations in Bldg. 771. A project of filter testing and development for prolonged transuranic service and waste reduction was formally initiated at Rocky Flats on July 1, 1975. The project is directed toward improving filtration methods which will prolong the life of HEPA filter systems without sacrificing effectiveness. Another important aspect of the project is to reduce the volume of HEPA filter waste shipped from the plant for long-term storage. Progress to September 30, 1976, is reported.
Date: February 1, 1977
Creator: Geer, J. A.; Buttedahl, O. I.; Skaats, C. D.; Terada, K. & Woodard, R. W.
Partner: UNT Libraries Government Documents Department

User's guide to the MESOI diffusion model: Version 1. 1 (for Data General Eclipse S/230 with AFOS)

Description: MESOI is an interactive, Langrangian puff trajectory model. The model theory is documented separately (Ramsdell and Athey, 1981). Version 1.1 is a modified form of the original 1.0. It is designed to run on a Data General Eclipse computer. The model has improved support features which make it useful as an emergency response tool. This report is intended to provide the user with the information necessary to successfully conduct model simulations using MESOI Version 1.1 and to use the support programs STAPREP and EXPLT. The user is also provided information on the use of the data file maintenance and review program UPDATE. Examples are given for the operation of the program. Test data sets are described which allow the user to practice with the programs and to confirm proper implementation and execution.
Date: September 1, 1982
Creator: Athey, G.F. & Ramsdell, J.V.
Partner: UNT Libraries Government Documents Department

XOQDOQ: computer program for the meteorological evaluation of routine effluent releases at nuclear power stations. Final report

Description: Provided is a user's guide for the US Nuclear Regulatory Commission's (NRC) computer program X0QDOQ which implements Regulatory Guide 1.111. This NUREG supercedes NUREG-0324 which was published as a draft in September 1977. This program is used by the NRC meteorology staff in their independent meteorological evaluation of routine or anticipated intermittent releases at nuclear power stations. It operates in a batch input mode and has various options a user may select. Relative atmospheric dispersion and deposition factors are computed for 22 specific distances out to 50 miles from the site for each directional sector. From these results, values for 10 distance segments are computed. The user may also select other locations for which atmospheric dispersion deposition factors are computed. Program features, including required input data and output results, are described. A program listing and test case data input and resulting output are provided.
Date: September 1, 1982
Creator: Sagendorf, J.F.; Goll, J.T. & Sandusky, W.F.
Partner: UNT Libraries Government Documents Department

Estimating radionuclide air concentrations near buildings: a screening approach

Description: For some facilities that routinely release small amounts of radionuclides to the atmosphere, such as hospitals, research laboratories, contaminated clothing laundries, and others, it is necessary to estimate the dose to persons very near the buildings from which the releases occur. Such facilities need simple screening procedures which provide reasonable assurance that as long as the calculated dose is less than some fraction of a relevant dose limit no individual will receive a dose in excess of that limit. Screening procedures have been proposed for persons living within hundreds of meters to a few kilometers from a source of radioactive effluent. This paper examines a screening technique for estimating long-term average radionuclide air concentrations within approximately 100 m of a building from which the release occurs. The technique is based on a modified gaussion plume model (HB model) which considers the influence of the tallest building within 100 m and is independant of atmospheric stability and downwind distance. 4 references, 2 tables.
Date: January 1, 1984
Creator: Miller, C.W. & Yildiran, M.
Partner: UNT Libraries Government Documents Department

Critique of methods for estimating plume depletion and deposition of airborne radionuclides

Description: A comparison is made between the methods for estimating plume depletion and deposition contained in Meteorology and Atomic Energy-1968 and the methods contained in United States Nuclear Regulatory Commission Regulatory Guide 1.111. Although Regulatory Guide 1.111 is intended only for use in determining compliance with 10 CFR 50, Appendix I requirements for light-water-cooled nuclear reactors, the methods contained in the Guide have the potential of being used for other types of nuclear facilities. Therefore, a comparison of methodologies is in order to identify any potential discrepancies. This comparison of the two approaches has highlighted three major concerns with regard to the Regulatory Guide 1.111 methods: (1) the dry deposition estimates derived from curves in the Regulatory Guide are not dependent on calculations of air concentration (2) for elevated releases estimates of dry deposition are too large close to the source; and (3) the plume depletion curves presented in the Guide are inconsistent with the results that would be expected for a surface depletion model.
Date: January 1, 1978
Creator: Miller, C.W. & Hoffman, F.O.
Partner: UNT Libraries Government Documents Department