In-vessel melt retention as a severe accident management strategy for the Loviisa Nuclear Power Plant
- IVO International Ltd., Vantaa (Finland)
- Univ. of California, Santa Barbara, CA (United States)
The concept of lower head coolability and in-vessel retention of corium has been approved as a basic element of the severe accident management strategy for IVO`s Loviisa Plant (VVER-440) in Finland. The selected approach takes advantage of the unique features of the plant such as low power density, reactor pressure vessel without penetrations at the bottom and ice-condenser containment which ensures flooded cavity in all risk significant sequences. The thermal analyses, which are supported by experimental program, demonstrate that in Loviisa the molten corium on the lower head of the reactor vessel is coolable externally with wide margins. This paper summarizes the approach and the plant modifications being implemented. During the approval process some technical concerns were raised, particularly with regard to thermal loadings caused by contact of cool cavity water and hot corium with the reactor vessel. Resolution of these concerns is also discussed.
- Research Organization:
- US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Office of Nuclear Regulatory Research; Brookhaven National Lab. (BNL), Upton, NY (United States)
- OSTI ID:
- 467946
- Report Number(s):
- NUREG/CP-0157-VOL.2; CONF-9610202-Vol.2; ON: TI97004274; TRN: 97:008412
- Resource Relation:
- Conference: 24. water reactor safety information meeting, Bethesda, MD (United States), 21-23 Oct 1996; Other Information: PBD: Feb 1997; Related Information: Is Part Of Proceedings of the twenty-fourth water reactor safety information meeting. Volume 2: Reactor pressure vessel embrittlement and thermal annealing; Reactor vessel lower head integrity; Evaluation and projection of steam generator tube condition and integrity; Monteleone, S. [comp.] [Brookhaven National Lab., Upton, NY (United States)]; PB: 443 p.
- Country of Publication:
- United States
- Language:
- English
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