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

Journal Article · · Nuclear Technology
OSTI ID:20067742

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 the Hanford site have been directed at identifying tanks in which this situation could exist. Problems encountered in screening motivated an effort to develop and 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. Approximate-reasoning 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. In a pilot study to investigate the utility of AR for flammable gas screening, the effort to implement such a model was found to be acceptable, and computational requirements were found to be 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 (US)
OSTI ID:
20067742
Journal Information:
Nuclear Technology, Vol. 130, Issue 3; Other Information: PBD: Jun 2000; ISSN 0029-5450
Country of Publication:
United States
Language:
English