Development of the hybrid safety systems for next generation PWR

Mitsubishi has developed a new concept of safety systems for next generation PWR which is called the Hybrid Safety Systems. They consist of the optimum combination of active and passive safety systems, to achieve enhanced safety, higher reliability, and better economy. The basic design of the systems, safety analyses and some design tests have been performed to confirm the propriety of the design. The applicability of the new concept to a large-scale PWR has been confirmed. The concept, system configurations and features of the systems will be described in this article. (author)