A probabilistic analysis of rapid boron dilution scenarios

Conference · Fri Jan 01 04:00:00 EST 1993

OSTI ID:6843661

Kohut, P; Diamond, D J

A probabilistic and deterministic analysis of a rapid boron dilution scenario related to reactor restart was performed. The event is initiated by a loss of off-site power during the startup dilution process. The automatic restart of the charging pump in such cases may lead to the accumulation of a diluted slug of water in the lower plenum. The restart of the reactor coolant pumps may send the diluted slug through the core, adding sufficient reactivity to overcome the shutdown margin and cause a power excursion. The concern is that the power excursion is sufficient in certain circumstances to cause fuel damage. The estimated core damage frequency based on the scoping analysis is 1.0--3.0E-05/yr for the plants analyzed. These are relatively significant values when compared to desirable goals. The analysis contained assumptions related to plant specific design characteristics which may lead to non-conservative estimates. The most important conservative assumptions were that mixing of the injected diluted water is insignificant and that fuel damage occurs when the slug passes through the core.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: NRC; Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6843661
• Report Number(s): BNL-NUREG-48227; CONF-930116--36; ON: DE93006388
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200 -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
BORON
COOLING SYSTEMS
DAMAGE
DILUTION
ELEMENTS
ENRICHED URANIUM REACTORS
EXCURSIONS
HYDROGEN COMPOUNDS
OPERATION
OXYGEN COMPOUNDS
POWER REACTORS
PROBABILISTIC ESTIMATION
PUMPS
PWR TYPE REACTORS
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR CORES
REACTOR OPERATION
REACTOR START-UP
REACTORS
SEMIMETALS
START-UP
THERMAL REACTORS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS