Passive decay heat removal in advanced LWR concepts

Abstract This paper explores the possibilities of developing a passive LWR design concept which could ensure sufficient decay heat removal in the absence of emergency primary coolant supply without exceeding the safe temperature limit on cladding, and which could achieve large nominal operating power output in the range 600–1000 MWe. Various possibilities of passive decay heat removal in LWR concepts are assessed and choke points limiting the heat transfer from the fuel to the ultimate heat sink are identified. To eliminate these choke points, new core configurations are studied. The most promising concept appears to be a pressure tube reactor with fueled solid matrix and a separate moderator as a heat sink.