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Title: Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2

Abstract

Three uranium hexafluoride-(UF{sub 6}-) specific models--HGSYSTEM/UF{sub 6}, Science Application International Corporation, and RTM-96; three dense-gas models--DEGADIS, SLAB, and the Chlorine Institute methodology; and one toxic chemical model--AFTOX--are evaluated on their capabilities to simulate the chemical reactions, thermodynamics, and atmospheric dispersion of UF{sub 6} released from accidents at nuclear fuel-cycle facilities, to support Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis. These models are also evaluated for user-friendliness and for quality assurance and quality control features, to ensure the validity and credibility of the results. Model performance evaluations are conducted for the three UF{sub 6}-specific models, using field data on releases of UF{sub 6} and other heavy gases. Predictions from the HGSYSTEM/UF{sub 6} and SAIC models are within an order of magnitude of the field data, but the SAIC model overpredicts beyond an order of magnitude for a few UF{sub 6}-specific data points. The RTM-96 model provides overpredictions within a factor of 3 for all data points beyond 400 m from the source. For one data set, however, the RTM-96 model severely underpredicts the observations within 200 m of the source. Outputs of the models are most sensitive to the meteorological parameters at large distances from the source and tomore » certain source-specific and meteorological parameters at distances close to the source. Specific recommendations are being made to improve the applicability and usefulness of the three models and to choose a specific model to support the intended analyses. Guidance is also provided on the choice of input parameters for initial dilution, building wake effects, and distance to completion of UF{sub 6} reaction with water.« less

Authors:
; ; ; ; ; ; ;  [1]
  1. Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis
Publication Date:
Research Org.:
Nuclear Regulatory Commission, Washington, DC (United States). Div. of Fuel Cycle Safety and Safeguards; Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis
Sponsoring Org.:
Nuclear Regulatory Commission, Washington, DC (United States)
OSTI Identifier:
569124
Report Number(s):
NUREG/CR-6481-Vol.2
ON: TI98003115; TRN: 98:003904
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Nov 1997
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; URANIUM HEXAFLUORIDE; RADIATION ACCIDENTS; FUEL CYCLE CENTERS; MATHEMATICAL MODELS; EVALUATION; SAFETY ANALYSIS; EMERGENCY PLANS; SOURCE TERMS; ENVIRONMENTAL TRANSPORT

Citation Formats

Nair, S K, Chambers, D B, Park, S H, Radonjic, Z R, Coutts, P T, Lewis, C J, Hammonds, J S, and Hoffman, F O. Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2. United States: N. p., 1997. Web. doi:10.2172/569124.
Nair, S K, Chambers, D B, Park, S H, Radonjic, Z R, Coutts, P T, Lewis, C J, Hammonds, J S, & Hoffman, F O. Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2. United States. https://doi.org/10.2172/569124
Nair, S K, Chambers, D B, Park, S H, Radonjic, Z R, Coutts, P T, Lewis, C J, Hammonds, J S, and Hoffman, F O. Sat . "Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2". United States. https://doi.org/10.2172/569124. https://www.osti.gov/servlets/purl/569124.
@article{osti_569124,
title = {Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2},
author = {Nair, S K and Chambers, D B and Park, S H and Radonjic, Z R and Coutts, P T and Lewis, C J and Hammonds, J S and Hoffman, F O},
abstractNote = {Three uranium hexafluoride-(UF{sub 6}-) specific models--HGSYSTEM/UF{sub 6}, Science Application International Corporation, and RTM-96; three dense-gas models--DEGADIS, SLAB, and the Chlorine Institute methodology; and one toxic chemical model--AFTOX--are evaluated on their capabilities to simulate the chemical reactions, thermodynamics, and atmospheric dispersion of UF{sub 6} released from accidents at nuclear fuel-cycle facilities, to support Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis. These models are also evaluated for user-friendliness and for quality assurance and quality control features, to ensure the validity and credibility of the results. Model performance evaluations are conducted for the three UF{sub 6}-specific models, using field data on releases of UF{sub 6} and other heavy gases. Predictions from the HGSYSTEM/UF{sub 6} and SAIC models are within an order of magnitude of the field data, but the SAIC model overpredicts beyond an order of magnitude for a few UF{sub 6}-specific data points. The RTM-96 model provides overpredictions within a factor of 3 for all data points beyond 400 m from the source. For one data set, however, the RTM-96 model severely underpredicts the observations within 200 m of the source. Outputs of the models are most sensitive to the meteorological parameters at large distances from the source and to certain source-specific and meteorological parameters at distances close to the source. Specific recommendations are being made to improve the applicability and usefulness of the three models and to choose a specific model to support the intended analyses. Guidance is also provided on the choice of input parameters for initial dilution, building wake effects, and distance to completion of UF{sub 6} reaction with water.},
doi = {10.2172/569124},
url = {https://www.osti.gov/biblio/569124}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1997},
month = {11}
}