Study of Station Blackout Accident Process in Taishan Nuclear Power Plant

According to the design features of the nuclear power plant in Taishan, a station blackout (SBO) at full power is a complex sequence, induced by the loss of offsite power (LOOP) combined with the loss of the emergency diesel generators (EDGs). This paper shall be performed the deterministic safety analysis of SBO without PSA study, and it mainly analyzes an overheating event of primary coolant resulting in the temporary unavailability of the steam generators (SGs) feeding systems during the station blackout. The analysis of this accident is carried out using the CATHARE2 thermal hydraulic code. The analysis pointed out that the final state can be reached after the operator performs the main manual actions such as startup of the SBO diesel generators from the main control room; startup of the two ASG pumps of trains 1 and 4; Local opening of the ASG header downstream the ASG pumps to enable the two power supplied ASG pumps to feed all the four SGs; initiation of a manual cooldown via the VDA in order to ensure the long term protection of the RCP pumps seals with respect to the thermal and mechanical loads. It corresponds to the achievement of a stable heat removal conditions by the emergency feedwater system (ASG) and the atmospheric steam dump system (VDA).Copyright © 2013 by ASME