VALIDATION OF COSTA ON PREDICTING CORE DAMAGE ACCIDENT PROGRESSION WITH THE TMI-2 ACCIDENT DATA

摘要

COSTA (A Computerized Support System for the Emergency Technical Advisory Body in Japan) has been developed by the Japan Atomic Energy Research Institute to provide national response capability during radiological accident emergencies. COSTA can be used to identify plant status and predict accident progression based on emergency data reported by the utility of an affected plant. To assess the capability of COSTA, it was applied to the TMI-2 accident progression in the reactor cooling system during the period that neither the emergency core cooling system nor the auxiliary feed water system was available. Although there are some differences in the steam generator between the TMI-2 plant and Japanese PWR plants, these differences would not significantly affect the accident progression of interest. A case study was also made by altering the amount and content of emergency data, as well as the timing of reporting. This study was performed to investigate the dependency of the COSTA predicted results upon the emergency data. This study showed that COSTA predicted results were reasonable when accurate emergency data were reported a few times an hour. [References: 13]