Equipment qualification for the Sizewell B pressurised water reactor

The programme of equipment qualification being undertaken in the United Kingdom in support of the Sizewell-B pressurized water reactor is described. The methods used are based on the Institution of Electronics and Electrical Engineers Standards developed for the United States nuclear programme. The preferred qualification method for electrical and control equipment uses type-testing and includes thermal and irradiation aging, seismic testing and harsh environment testing. Functional testing is also performed throughout the qualification programme. A typical temperature/pressure profile against time for harsh environment testing is shown. The National Nuclear Corporation's harsh environment test facility is described. (U.K.)