ISLOCA Analysis for a Typical 1000MW PWR: Accident Progression, FP Distribution, and Accident Management

An interfacing system loss of coolant accident (ISLOCA) is a loss of primary coolant outside the containment via a system that interfaces with the reactor coolant system (RCS) and for which the pressure boundary is outside the containment. The fission product behaviors with a modeling of an auxiliary building, which have not been evaluated for domestic nuclear plants in Korea, are very different from the behaviors without the modeling of an auxiliary building, and are scenario-specific. An interfacing system loss of coolant accident (ISLOCA) is a loss of primary coolant outside the containment via a system that interfaces with the reactor coolant system (RCS) and for which the pressure boundary is outside the containment. An ISLOCA is presumed to result from exposing low pressure piping of the interfacing system to the full pressure of the primary system due to failures of multiple pressure barriers. An ISLOCA will provide a direct path, which bypasses the containment, for the release of radioactive materials into the environment. The fission product behaviors with a modeling of an auxiliary building, which have not been evaluated for domestic nuclear plants in Korea, are very different from the behaviors without the modeling of an auxiliary building, and are scenario-specific. Accordingly, a scenario-specific analysis of the fission product source terms during a severe accident might be noteworthy. This paper is intended to evaluate the characteristics of a fission product source term release or distribution during an ISLOCA with the modeling of an auxiliary building in a typical 1000 MW PWR. In addition, an evaluation is included for the effectiveness of external cooling water injection strategies using fire trucks during a potential ISLOCA accident.