An analysis of risk reduction methods for interfacing system LOCAs at PWRs

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5226322

Kohut, P; Bozoki, G; Fitzpatrick, R

Interfacing system loss-of-coolant accidents (ISLs) refers to events where the integrity of the Reactor Coolant System (RCS) pressure boundary is breached through failure of isolation valves which separate a support system of lower design pressure. The overpressurization of the support system will affect its availability and may further affect the availability of various safety systems required to mitigate the accident. In addition, it may result in a scenario where primary coolant is directly discharged into the outside environment by passing the containment. The Reactor Safety Study (WASH-1400) predicted that ISL events were significant contributors to risk even though they were calculated to be relatively low frequency events. However, there are substantial uncertain involved in determining the probability and consequences of the ISL sequences. For example, the assumed valve failure modes, common cause contributions and the location of the break/leak are all uncertain and can significantly influence the predicted risk from ISL events. The present study was performed to investigate the vulnerability of pressurized water reactor designs to ISLs and identify any improvements that could significantly reduce the frequency of these events.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5226322
• Report Number(s): BNL-NUREG-40756; CONF-880601-15; ON: DE88006295
• Country of Publication: United States
• Language: English

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