Safety first as Mühleberg closure approaches

The power plant and dam at Mühleberg Keystone

Swiss nuclear inspectors say the Mühleberg power station must continue to invest in its long-term safety right up to its shut-down in 2019. Meanwhile, nuclear critics are starting to turn their attention to the Beznau plants, the world’s oldest.

This content was published on November 22, 2013 - 17:15

The Federal Nuclear Safety Inspectorate (ENSI) announced on Thursday that Swiss energy company BKW must meet strict long-term safety standards “until the plant’s final day” in 2019. BKW announced on October 30 that the plant is due to be taken off the grid in 2019, instead of 2022 as previously planned, because of "uncertainty surrounding political and regulatory trends”.

Five out of 18 safety measures must be implemented this year and 11 in 2014, ENSI said. The four major ones focus on stabilising the core reactor wall, as well as an earthquake- and flood-resistant system of cooling combustible fuel elements and an additional system to evacuate excessive heat.

ENSI adds that if the rest of the requirements are not implemented by 2017, Mühleberg could be taken offline early.  The inspectors are sticking to their demand for additional safety measures following the 2011 Fukushima nuclear disaster.

Environmental groups and the Green Party have meanwhile consistently demanded the site near Bern – commissioned in 1972 – be closed down immediately over safety concerns.

‘Guaranteed 100% safe’

This Jenny, a Swiss People’s Party senator from canton Glarus and a member of the Environment, Planning and Energy Commission, praised ENSI’s decision.

“ENSI has to guarantee 100% safety for Mühleberg until 2019. And if it sticks to these measures it will be the case,” he told

Jenny said claims by anti-nuclear critics that BKW and ENSI had reached a secret ‘deal’ over the safety measures was “political shadow-boxing”.

However, there was strong opposition to ENSI’s decision. The Young Greens said they were “appalled by the horse-trading between ENSI and BKW”. Florian Kasser from Greenpeace also described the retrofitting as a token gesture and said the decision was a bad signal for ENSI’s independence.

But not all opponents feel the same way.

“ENSI is not deviating too far from the long-term security measures demanded. In that sense it has acted correctly and is well-positioned,” said Social Democrat Roger Nordmann, who is also a member of the environment commission.

Swiss reactors

Switzerland currently has five nuclear reactors which account for about 40 per cent of the energy produced in the country: Beznau I (commissioned 1969), Beznau II (1972), Mühleberg (1972), Gösgen (1978) and Leibstadt (1984).
After the disaster at Fukushima in March 2011, the Swiss government decided to decommission all the nuclear power plants starting in 2019 and ending by 2034. However, no exact dates were given for the individual reactors to be shut down.

In March 2012, the Federal Administrative Court ordered the closure of Mühleberg by June 2013 for safety reasons unless the operators, BKW, could show they were prepared to invest massively in maintenance and repair.

In March 2013, the Federal Court upheld a complaint by BKW, overturning the Federal Administrative Court decision. As a result, BKW had to implement a set of safety measures demanded by the authorities based on a strict timetable.

In October 2013, BKW announced it would take its Mühleberg nuclear power station off the grid in 2019. The plant is frequently cited by opponents of nuclear energy as ready for closure.

End of insertion

‘No alternative’

Although BKW has the possibility of presenting cheaper safety solutions by next summer, Nordmann does not think the firm has any choice but to implement the main safety demands.

“I don’t see any alternatives to a more solid core reactor and the building of a separate emergency cooling system,” he said, adding that a shut-down at the end of 2017 was the most likely scenario.

“It makes no economic sense to invest CHF150 million in the plant for two more years.”

Nordman said BKW’s announcement in October to take Mühleberg off the grid in 2019 was a much more important decision than that of ENSI.

“BKW’s decision to shut down the Mühleberg plant in a reasonable time is both pioneering and courageous,” he commented.

It contradicts the nuclear lobby’s claim that a shut-down date could not be fixed in advance, he argued.

More bite

The centre-left politician is keen to build on momentum from the Mühleberg shut-down decision to push for further atomic energy phase-outs.

While he admits that his preference for a 40-year time limit on plants would not get past parliament, he believes ENSI’s idea of demanding more safety measures beyond a plant’s 40th year of service might get backing.

“It’s essential that the operators tell ENSI how long they want to run the plants so that the authorities can precisely calculate the safety measures based on the deadline,” said Nordmann.

If operators don’t comply with these wider safety margins, ENSI must be able to order their shutdown, and for this the authorities need to be better armed legally, he commented.

Beznau next

Now that tighter safety regulations are being enforced right up to the end of the operational life of a power plant, Nordmann wants to push for the closure of the Beznau I and II power plants, in canton Aargau. These are the two oldest in the world, built in 1969 and 1972, respectively. 

"In Beznau there are high risks of flooding. If radiated water were to escape from the cooling system, hundreds of millions of people would be affected along the Rhine River,” he declared.

Jenny remains unperturbed by Nordmann’s new line of attack, however. He is not worried about ENSI possibly losing public credibility. And he doesn’t believe the Mühleberg decision gives fresh impetus to the anti-nuclear brigade and their call for rules on the lifespan of nuclear plants.

"We shouldn’t get too excited by the fact that something is happening at just one out of 100 nuclear plants, “ said Jenny

In compliance with the JTI standards

In compliance with the JTI standards

More: SWI certified by the Journalism Trust Initiative

You can find an overview of ongoing debates with our journalists here. Please join us!

If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at

Sort by

Change your password

Do you really want to delete your profile?

Your subscription could not be saved. Please try again.
Almost finished... We need to confirm your email address. To complete the subscription process, please click the link in the email we just sent you.

Discover our weekly must-reads for free!

Sign up to get our top stories straight into your mailbox.

The SBC Privacy Policy provides additional information on how your data is processed.