In a safety case submitted to Switzerland’s Federal Nuclear Safety Inspectorate (ENSI), NPP owner and operator Axpo said irregularities detected in early summer of 2015 have no safety impact on the material properties of the reactor pressure vessel (RPV) at unit 1 of the Beznau NPP. Axpo said the physical integrity tests confirm “an adequate safety margin for a service life of 60 years”. The extensive tests were carried out over the past months on the basis of a replica of the RPV ring. Axpo said the safety case was submitted to ENSI on 14 November and includes all the results of tests performed on the RPV, including analyses of the source and formation of inclusions in the RPV base material.
Axpo said the safety case provides “verifiable proof” that the reliability and safety of Beznau-1 is ensured “in keeping with the state of the art of science and technology, as well as national and international standards”. Axpo said it has no safety or technical concerns regarding the continued operation of the plant until about 2030. ENSI will review the safety case, together with an international review panel, and take the decision on restarting the plant. The two 365MWe Westinghouse units at Beznau NPP are the oldest power reactors in Switzerland. Unit 1 began operating in 1969, and unit 2 in 1972. In addition to providing power, both units also produce district heating.