AP600 wins good grades in containment cooling tests

Westinghouse's response to the need for simpler reactors that produce power more cheaply and improve public confidence in their safety is the AP600, an advanced passive PWR. The AP600 is based on Westinghouse's two loop PWR, but the design has been simplified considerably. The operating systems are simpler, and safety systems rely predominantly on gravity, convection and natural circulation. The simplified systems increase availability and reduce equipment and seismic building volume, reducing capital costs and construction time. The passive core cooling and passive containment cooling systems (PCCS) are the keystones on which the design is built. The first level of defence - proven conventional systems - is backed up by passive safety systems that protect the plant even in remote cases where operator actions are not possible or not appropriate. Westinghouse has submitted the Standard Safety Analysis Report on AP600 to the US Nuclear Regulatory Commission (NRC). The report is supported by a series of tests aimed at confirming the design's passive cooling capability which is described in this article. (author)