Operating experience of the EBR-II intermediate heat exchanger and the steam generator system

Experimental Breeder Reactor-II (EBR-II) is an experimental liquid metal fast breeder reactor located at the Idaho National Engineering Laboratory. It consists of an unmoderated, heterogeneous, sodium-cooled reactor with a nominal thermal power output of 62.5 MW; an intermediate closed loop of secondary sodium coolant; and a steam plant that produces 20 MW of electrical power through a conventional turbine generator. The EBR-II heat transport system continues to operate satisfactorily after 18 years. This represents about 89,000 hours of steaming, which results in a total integrated thermal power production of about 215,000 MWd. In this time, the steam generator has experienced over 580 plant startups and 349 reactor scrams. The plant capacity factor for the past five years has been in excess of 70%, and in fact has averaged almost 60% over the last thirteen years. This excellent record is partly attributable to the trouble-free operation of the steam generator which, aside from an initial construction tube-to-tubesheet weld defect, has had a plant availability of 100%.