유일용  김태우

Vol. 40,  No. 1, pp. 81-87, Feb.  2025
10.14341/JKOSOS.2025.40.1.81

SBLOCA with HPSI Fail SPACE code OPR1000 safety analysis

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After the Fukushima nuclear accident of 2011 (which was classified as a Level 7 accident on the International Nuclear and Radiological Event Scale (INES standard), the Korean nuclear regulatory body began to contemplate the possibility of accidents more serious than the design-basis accidents (DBA) that have been applied to the country’s nuclear power plants. This led to the revision of the Korean Nuclear Safety Act, which expanded the scope of accident management from DBA to multiple-failure accidents. A Small-Break Loss-of-Coolant Accident (SBLOCA) concurrently occurring with safety injection or recirculation failure is defined as an accident in which a small loss of coolant is followed by the failure of either the safety injection system or the recirculation operation, leading to further escalation of the situation. This type of accident falls within the category of nine multiple-failure accidents, with the allowable criterion being that the accident causes no significant damage to the fuel inside the reactor or spent fuel storage facility. This study utilizes a proprietary safety analysis code, SPACE (Safety and Performance Analysis CodE for Nuclear Power Plants), which is based on the OPR1000 model, to analyze the scenario of an SBLOCA that is simultaneously accompanied by a high-pressure safety injection failure at an operational power plant. To verify their validity, the results obtained from the SPACE code are compared to those from the RELAP5 code in the multiple-failure accident capability assessment report of the accident management plan.