The ageing Beznau nuclear power station is not a safety risk and ‘irregularities’ found in the reactor’s pressure vessel are insignificant and small clusters of contaminated material and not hundreds of tiny holes, the plant operator Axpo insists.
“It’s not about ‘holes’, as Swiss newspaper Tages-Anzeiger reported, but very small amounts of material contaminations,” Axpo spokesperson Tobias Kistner told swissinfo.ch in an emailed statement on Thursday.
“When it comes to the reactor safety, these irregularities do not represent a problem.”
Axpo’s reply came the day after the German-language newspaper reported that the pressure vessel inside the Beznau I reactor contained around 1,000 holes of half a centimetre in diameter, citing two independent sources that were not identified.
According to one of the sources, the situation at Beznau I may be far worse than Axpo had declared in July when it first detected “irregularities” in the reactor’s pressure vessel during its annual resting period.
Kistner replied that the small irregularities date back to the production process of the vessel and seven "clusters" of contaminated material in the pressure vessel were being examined in detail.
“Nevertheless, after what we have found out so far, we still do not think that there might be any safety problem with Beznau I,” he declared.
The Swiss Federal Nuclear Safety Inspectorate (ENSI) has nonetheless asked Axpo to carry out further tests and measurements, Kistner said.
Back on the grid?
Built in 1969, Beznau I is the oldest working nuclear reactor in the world. It is located in canton Aargau on an artificial island on the Aare River, 40km northwest of Zurich near the German border.
Annual maintenance work stopped the Beznau 1 reactor in March. On July 16, Axpo said the plant would resume operating at the end of October. Kistner said it was now more likely to be “the end of February 2016”.
Florian Kasser, from Greenpeace Switzerland, criticised Axpo by saying the ageing plant should “never be reconnected to the grid”.
“Continuing to operate the plant would be completely irresponsible and negligent,” he said in a statement, adding that Axpo should end this “game of hide and seek”.
After the Fukushima disaster in 2011, the Swiss government decided to decommission all five of Switzerland’s nuclear power plants between 2019 and 2034, but gave no exact dates for shutting down the individual reactors.