Abstract: Criticality safety is a major concern for nuclear safety in new fuel storage. Double contingency accident of new fuel criticality safety analysis must be considered for new fuel storage. SCALE was used for the criticality analysis of new fuel stored in cask washdown pit in Sanmen Nuclear Power Plant in this paper. The results show that plans for new fuel storage in cask washdown pit in Sanmen Nuclear Power Plant are safe even when two independent abnormal events occur simultaneously.

Key words: AP1000 new fuel, cast washdown pit, criticality safety analysis