Development of the severe accident management guidelines (SAMG) for Ulchin Nuclear Power Plant Unit 3, 4, 5 6

摘要

This paper describes the development process of the severe accident management guidelines (SAMG) for Units 3, 4, 5 & 6 of Ulchin Nuclear Power Plant. The units are Korean Standard Nuclear Power (KSNP) plant, 1000 MWe class pressurized water reactor (PWR) with two loops of primary coolant system. The severe accident management guidelines for the units have been completed in 2002. The generic severe accident management guidance for Korean Standard Nuclear Power Plant has been used as the basis when developing Ulchin severe accident management guideline. Result of probabilistic safety assessment (PSA) for each unit was reviewed to integrate its insight into the SAMG. It indicates that each unit has a balanced design to any specific initiating events for core damage. Seven severe accident management strategies are applied in Ulchin SAMG. Seven strategies are (1) Inject into the steam generator (2) Depressurize the RCS (3) Inject into the RCS (4) Inject into the containment (5) Control the fission product release into environment (6) Control the containment pressure and temperature and (7) Control hydrogen concentration in the containment. The range and capability of essential instrument for performing the strategies are assessed. Computational aids are developed to complement the unavailable instrument during the accident and to assist the operator's decision choosing strategies. To examine the ability of the SAMG to fulfill its intended function, small loss of coolant accident (SLOCA) with the failure of safety injection was selected as a reference scenario. The scenario was analyzed using MAAP code. The evaluation of the SAMG using this sequence has been successfully completed.