MELCOR analyses of drywell flammability

Conference · Sun Jan 01 04:00:00 EST 1989 · Transactions of the American Nuclear Society; (USA)

OSTI ID:6529354

Dingman, S E; Kelly, J E ^[1]

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1. Sandia National Lab., Albuquerque, NM (USA)

The MELCOR computer code, which has been developed at Sandia National Laboratories for the US Nuclear Regulatory Commission as a tool for calculating realistic estimates of severe-accident consequences and source terms, has been used to analyze a series of containment issues for station blackout sequences for the Grand Gulf nuclear power plant. Grand Gulf is a boiling water reactor-6 reactor with a Mark-III containment. Unless the suppression pool is bypassed in a severe accident, the source terms following containment failure will be relatively low for the Grand Gulf Mark-III containment design. Consequently, failure of the drywell wall is a very important issue. In station blackout sequences the igniters, which would provide controlled burning in other sequences, will not be operable, and the drywell wall could be threatened by containment burns. Hence, determining the distribution of hydrogen between the drywell and outer containment is important for the Grand Gulf plant because it affects the containment pressure rise during burning. In addition, if significant hydrogen is present in the drywell at vessel breach, the additional pressurization from burning the hydrogen could result in drywell wall failure. The likelihood of forming a flammable mixture in the drywell during a station blackout was examined with MELCOR. The results of the MELCOR calculations addressing drywell flammability are summarized in this paper.

• OSTI ID: 6529354
• Report Number(s): CONF-891103--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (USA) Journal Volume: 60
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
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220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
BLACKOUTS
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COMBUSTION PROPERTIES
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HYDROGEN
IGNITION
M CODES
MOLTEN METAL-WATER REACTIONS
NATIONAL ORGANIZATIONS
NONMETALS
POWER REACTORS
PRESSURE SUPPRESSION
PRESSURE VESSELS
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RADIOACTIVITY TRANSPORT
REACTOR ACCIDENTS
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SOURCE TERMS
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