ABSTRACT
Severe accident management guidance (SAMG) (KAERI, 1998) which all of the Korea light water reactors have developed and implemented are aimed at a mitigation of core damage accidents. The guidance addresses various mitigation actions to return the plant to a controlled stable state following the onset of significant core damage by using plant specific safety features. For example, the cooling water can be injected into the reactor cavity to prevent a molten corium-concrete interaction, or spray systems will be operated in case of a high containment pressure. However, they do not always provide a fully meaningful diagnosis for a current accident scenario or a prediction for an expected accident progression. Under severe accident situations, operator actions, which should be executed with a stressful condition, may be very complex and difficult in the case that the diagnostic information or the tentative accident progression information is not provided. To improve this situation, a database and simulator supported accident management systems are under development.
