Influence of steam generator plugging and break size on large-break loss-of-collant accidents

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Nuclear Safety

OSTI ID:226777

Stritar, A; Mavko, B ^[1]

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1. Jozef Stefan Institute, Ljubljana (El Salvador)

The large-break loss-of-coolant accident (LBLOCA) is the design-basis accident in the Krsko pressurized-water reactor, the only power reactor in Slovenia. Because numbers of steam generator tubes are plugged as the steam generator ages, and this directly influences the primary system behavior during an LBLOCA, this accident was re-examined assuming various proportions of blocked tube from 0 to 22%. The size of the break was changes from 25 to 45% of the initial cold-leg cross section. The analysis was made with RELAP4/MOD6 as the main code in the conservative mode rather than as the best-estimate code. The methodology separately considers the blowdown phase, the refill phase, and the reflood phase. It was found that the peak clad temperature rises as plugging increases up to about 10% plugging and tends to be constant or even decrease as the plugging increases beyond this point. It was also found that results are strongly dependent on the methodology used. 17 refs., 9 figs., 3 tabs.

• OSTI ID: 226777
• Journal Information: Nuclear Safety, Journal Name: Nuclear Safety Journal Issue: 3 Vol. 32; ISSN 0029-5604; ISSN NUSAAZ
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
CLOSURES
LOSS OF COOLANT
PWR TYPE REACTORS
STEAM GENERATORS
TUBES