Replacement vessel lids for Beznau reactors

26 January 2009

Swiss utility Nordostschweizerische Kraftwerk (NOK) plans to replace the lids of the reactor pressure vessels at the two-unit Beznau nuclear power plant as part of a programme to prolong the plant's operating life.
 

Beznau 1 and 2 (Image: Axpo)

NOK said that it will replace the two pressure vessel lids in 2013, as well as replacing the control rod drives at the plant, as part of a SFr100 million ($87 million) investment to keep the plant running safely and reliably.
 
The company said that, despite after some 40 years of operation, the existing lids show no signs of damage. However, NOK said that it would replace them "as a preventative measure." The move, the company said, was based on the operating experience of about 80 other similar plants around the world, which had shown that after extended operation, regular inspections and some repairs of the lids would likely be required.
 
The two 365 MWe Westinghouse pressurised water reactors (PWRs) at the Beznau plant are the oldest power reactors in Switzerland. Unit 1 began operating in 1969, while unit 2 entered operation in 1972. In addition to providing power, both units also produce district heating. Their operating life is expected to run until 2020. An application has already been submitted to the Swiss Federal Office of Energy for preliminary approval to construct a replacement unit at Beznau, with a capacity of 1600 MWe.
 
NOK, part of the Axpo Group, said that investing in the new pressure vessel lids would ensure that Beznau units 2 and 3 would continue operating until the planned Beznau 3 begins operation. The Beznau plant currently meets some 10% of Switzerland's electricity demand.
 

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