Approaches to the Management of Severe Accidents in SFP at Armenian NPP

The nuclear energy sector of Armenia includes one nuclear power plant — Armenian NPP (ANPP). ANPP consists of two units with Soviet design WWER-440/270 model reactor that is a version of the WWER-440/230 serial model with special seismic considerations in the design. Unit 1 started its commercial operation in 1976 and the Unit 2 in 1980. Both units were shut down shortly after the earthquake of December 7th, 1988. Following the completion of repair and safety upgrading activities Unit 2, after 6.5 years of shutdown, restarted operation in 1995 and it has been operational since then. Unit 1 reactor plant remains in long-term shutdown condition (with no fuel in the core). The Spent Fuel Pools (SFPs) of both units are currently in operation — the fuel discharged from the operating unit 2 reactor core is put first in the SFP of that unit, then, after several years of storage, is transferred to the SFP of the unit 1. When the decay heat is low enough the spent fuel assemblies are moved from the SFP of the unit 1 to the spent fuel interim 'dry' storage facility (Dry Casks for long term Storage of Spent Nuclear Fuel).