Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: Several accidents about ERHRS of CEFR

Zhang, D. (China Institute of Atomic Energy, Beijing (China))

Abstract

An analysis about several unusual accidents about Emergency Residual Heat Removal System (ERHRS) of China Experiment Fast Reactor (CEFR) is present. CEFR is a pool-type sodium-cooled fast reactor. The ERHRS of this reactor is designed in passive principle, which enhance the interior reliability of CEFR. It is consist of two sets of independent channels. Each channel is comprised of decay heat exchanger (DHX), intermediate circuit, sodium-air heat exchanger (AHX) and related auxiliary system. Both DHX are located in the hot pool of the main vessel directly, which is used to cool the hot sodium. The whole set of ERHRS is completely passive except the ventilation valves of AHX. But, as a very important set of engineered safety features which is the final way to remove the heat from the reactor core, it is necessary to pay attention to all of possibilities that may reduce this ability. Several accidents are analyzed include the ventilation valves couldn’t be opened, only one set of ERHRS could work and so on. The calculation results show that the ERHRS can keep the reactor in a safety status. Even though it is, experiments are necessary in the view of engineering yet.

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key words: after-heat removal; auxiliary systems; cefr reactor; engineered safety systems; heat exchangers; reliability; risk assessment
Reference:
Technical committee meeting on unusual occurrences during LMFR operation. Vienna (Austria) 9-13 Nov 1998
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--1180, pp:216-225