An approximate-reasoning-based method for screening high-level waste tanks for flammable gas

Conference · Wed Jul 01 04:00:00 EDT 1998

DOI:https://doi.org/10.2172/290839· OSTI ID:663373

Eisenhawer, S W; Bott, T F; Smith, R E

The in situ retention of flammable gas produced by radiolysis and thermal decomposition in high-level waste can pose a safety problem if the gases are released episodically into the dome space of a storage tank. Screening efforts at Hanford have been directed at identifying tanks in which this situation could exist. Problems encountered in screening motivated an effort to develop an improved screening methodology. Approximate reasoning (AR) is a formalism designed to emulate the kinds of complex judgments made by subject matter experts. It uses inductive logic structures to build a sequence of forward-chaining inferences about a subject. AR models incorporate natural language expressions known as linguistic variables to represent evidence. The use of fuzzy sets to represent these variables mathematically makes it practical to evaluate quantitative and qualitative information consistently. The authors performed a pilot study to investigate the utility of AR for flammable gas screening. They found that the effort to implement such a model was acceptable and that computational requirements were reasonable. The preliminary results showed that important judgments about the validity of observational data and the predictive power of models could be made. These results give new insights into the problems observed in previous screening efforts.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Management and Administration, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 663373
• Report Number(s): LA-UR--98-229; CONF-980307--; ON: DE98003494
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
AMMONIA
FLAMMABILITY
HANFORD RESERVATION
HIGH-LEVEL RADIOACTIVE WASTES
HYDROGEN
MATHEMATICAL MODELS
METHANE
STORAGE FACILITIES
TANKS
UNDERGROUND STORAGE