The Blackout Accident Phenomena And Design Improvements

Station break-out (SBO) is the main initial event which results in reactor core melt down. Aiming at the evolved process of the SBO accident in the four units of Qinshan Phase II, this paper mainly discusses the particular measures in design and analyzes the effect of both the preventive and mitigative measures adopted on the SBO accident. Finally, improvement suggestions of the accident management are proposed.Through the PSA as well as the comparison with other pressurized water reactors, the statistics show that the auxiliary electrical power in and out of Qinshan Phase II is quite safe and reliable, so the chances for the SBO or the possibility of damaging the reactor core are rather low and the safe operation of the plant is well guaranteed with the improvement in design and concerned measures adopted to mitigate the serious accidents.Besides, the paper combines the discussion of serious accident planning system (including the system for SBO) with the real situation for accident managing, pointing out the key measures that target the improvement in mitigating serious accidents to prevent and mitigate the serious accidents. Meanwhile, the paper adopts and assimilates the experiences home and abroad in NP construction, putting forward route map and main task of the Serious Accident Managing Guide (SAMG), furthermore, some improvement suggestions are proposed in the light of the real situation.With the help of the discussion shown in this paper, not only can we have a clear and accurate picture of the serious consequence in case of SOB of Qinshan Phase II also the initial the settlement plans for the weakness in design and related problems, moreover, some preventive and mitigative measures aiming at the severe accidents occurred in SOB are also proposed.