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Title: An approximate-reasoning-based method for screening flammable gas tanks

Abstract

High-level waste (HLW) produces flammable gases as a result of radiolysis and thermal decomposition of organics. Under certain conditions, these gases can accumulate within the waste for extended periods and then be released quickly into the dome space of the storage tank. As part of the effort to reduce the safety concerns associated with flammable gas in HLW tanks at Hanford, a flammable gas watch list (FGWL) has been established. Inclusion on the FGWL is based on criteria intended to measure the risk associated with the presence of flammable gas. It is important that all high-risk tanks be identified with high confidence so that they may be controlled. Conversely, to minimize operational complexity, the number of tanks on the watchlist should be reduced as near to the true number of flammable risk tanks as the current state of knowledge will support. This report presents an alternative to existing approaches for FGWL screening based on the theory of approximate reasoning (AR) (Zadeh 1976). The AR-based model emulates the inference process used by an expert when asked to make an evaluation. The FGWL model described here was exercised by performing two evaluations. (1) A complete tank evaluation where the entire algorithm ismore » used. This was done for two tanks, U-106 and AW-104. U-106 is a single shell tank with large sludge and saltcake layers. AW-104 is a double shell tank with over one million gallons of supernate. Both of these tanks had failed the screening performed by Hodgson et al. (2) Partial evaluations using a submodule for the predictor likelihood for all of the tanks on the FGWL that had been flagged previously by Whitney (1995).« less

Authors:
; ;
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Assistant Secretary for Management and Administration, Washington, DC (United States)
OSTI Identifier:
290839
Report Number(s):
LA-UR-98-1207
ON: DE99000571; TRN: 99:002277
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Mar 1998
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; HIGH-LEVEL RADIOACTIVE WASTES; RADIOACTIVE WASTE STORAGE; TANKS; DEGASSING; FLAMMABILITY; HANFORD RESERVATION; SAFETY ANALYSIS; COMPUTERIZED SIMULATION

Citation Formats

Eisenhawer, S W, Bott, T F, and Smith, R E. An approximate-reasoning-based method for screening flammable gas tanks. United States: N. p., 1998. Web. doi:10.2172/290839.
Eisenhawer, S W, Bott, T F, & Smith, R E. An approximate-reasoning-based method for screening flammable gas tanks. United States. https://doi.org/10.2172/290839
Eisenhawer, S W, Bott, T F, and Smith, R E. 1998. "An approximate-reasoning-based method for screening flammable gas tanks". United States. https://doi.org/10.2172/290839. https://www.osti.gov/servlets/purl/290839.
@article{osti_290839,
title = {An approximate-reasoning-based method for screening flammable gas tanks},
author = {Eisenhawer, S W and Bott, T F and Smith, R E},
abstractNote = {High-level waste (HLW) produces flammable gases as a result of radiolysis and thermal decomposition of organics. Under certain conditions, these gases can accumulate within the waste for extended periods and then be released quickly into the dome space of the storage tank. As part of the effort to reduce the safety concerns associated with flammable gas in HLW tanks at Hanford, a flammable gas watch list (FGWL) has been established. Inclusion on the FGWL is based on criteria intended to measure the risk associated with the presence of flammable gas. It is important that all high-risk tanks be identified with high confidence so that they may be controlled. Conversely, to minimize operational complexity, the number of tanks on the watchlist should be reduced as near to the true number of flammable risk tanks as the current state of knowledge will support. This report presents an alternative to existing approaches for FGWL screening based on the theory of approximate reasoning (AR) (Zadeh 1976). The AR-based model emulates the inference process used by an expert when asked to make an evaluation. The FGWL model described here was exercised by performing two evaluations. (1) A complete tank evaluation where the entire algorithm is used. This was done for two tanks, U-106 and AW-104. U-106 is a single shell tank with large sludge and saltcake layers. AW-104 is a double shell tank with over one million gallons of supernate. Both of these tanks had failed the screening performed by Hodgson et al. (2) Partial evaluations using a submodule for the predictor likelihood for all of the tanks on the FGWL that had been flagged previously by Whitney (1995).},
doi = {10.2172/290839},
url = {https://www.osti.gov/biblio/290839}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Mar 01 00:00:00 EST 1998},
month = {Sun Mar 01 00:00:00 EST 1998}
}