The Hybrid Safety Features of The APR

Current Advanced Light Water Reactors (ALWRs) can be divided into two categories; active ALWRs and passive ALWRs. APR1400, EPR, and APWR belong to active ALWR, and AP1000 and ESBWR belong to passive ALWR. Each concept has its own pros and cons. Active safety system can provide highly efficient cooling ability and they use proven technologies. On the other hand, they require many equipment and components, so they are expensive in general. And they require external electrical source to actuate. Passive safety systems, on the other hand, are very simple and they require many equipment and components, so they are expensive in general. And they require external electrical source to actuate. Passive safety systems, on the other hand, are very simple and they do not require external electrical source. However, their cooling intensity is relatively low. In order to choose advantages of both concepts, Advanced Power Reactor Plus (APR+) adopts hybrid safety concept. The reference design of APR+ is APR1400, which is active ALWR developed in Korea. Based on safety system design of APR1400, we have adopted passive safety system, selectively. The selection criteria are safety, economics, and performance. The performance should be equal to or better than that of APR1400 and both safety and economics should be enhanced. Based on these criteria, APR+ adopts passive safety systems such as the advanced safety injection tank with fluidic device+, the passive aux. feedwater system, and the passive in-vessel retention system. Each passive feature contributes the enhancement of safety and economics. For example, the core damage frequency and the construction cost are reduced as much as 30% and 20 million dollars, respectively