Rapid-response analysis of the Davis-Besse loss-of-feedwater event on June 9, 1985

Conference · Wed Jan 01 00:00:00 EST 1986

OSTI ID:5664399

Lime, J F; Nassersharif, B; Boyack, B E

At the request of the US Nuclear Regulatory Commission (NRC), we performed a rapid-response analysis of the loss-of-feedwater (LOFW) event that occurred at the Toledo Edison Davis-Besse plant on June 9, 1985. The initial 831 s of the plant transient were simulated and, in addition, four postulated transients were calculated to determine how the plant would have responded if feedwater had not been restored, and how it would have responded to a feed-and-bleed (FAB) decay-heat removal procedure initiated at different times. The Transient Reactor Analysis Code was used for this analysis. We completed these calculations within a two-week period and provided a report to the NRC 30 days later. Our analysis showed that FAB was a viable decay-heat-removal procedure for the Davis-Besse plant for the initiation times analyzed. With complete LOFW and no alternate decay-heat removal procedure, we calculated that core uncovery would have occurred at about 9200 s. FAB initiated at 8 min and 13 min after complete LOFW, which in the actual LOFW transient occurred 6 min after the initiating event of a main-feedwater pump trip, was successful in that the primary system remained subcooled and water-solid throughout the transient. FAB initiated at 28 min after complete LOFW was considered successful even though it resulted in a loss of subcooling, a net loss in primary inventory, and a slow voiding of the primary system. The core would have remained covered for the nine hours that we estimated for the primary pressure to decrease to the residual-heat-removal pressure.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5664399
• Report Number(s): LA-UR-86-1782; CONF-860906-8; ON: TI86011223
• Resource Relation: Conference: Advances in reactor physics and safety meeting, Saratoga Springs, NY, USA, 17 Sep 1986
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
DAVIS BESSE-1 REACTOR
LOSS OF FLOW
DAVIS BESSE-2 REACTOR
DAVIS BESSE-3 REACTOR
AFTER-HEAT REMOVAL
FEEDWATER
HEAT TRANSFER
HYDRAULICS
US NRC
ACCIDENTS
ENERGY TRANSFER
ENRICHED URANIUM REACTORS
FLUID MECHANICS
HYDROGEN COMPOUNDS
MECHANICS
NATIONAL ORGANIZATIONS
OXYGEN COMPOUNDS
POWER REACTORS
PWR TYPE REACTORS
REACTOR ACCIDENTS
REACTORS
REMOVAL
THERMAL REACTORS
US ORGANIZATIONS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
210200 - Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled