Germany’s environment minister has asked Belgium to take its Tihange-2 and Doel-3 pressurised water reactor (PWR) units offline for further investigations into their safety, the German federal ministry for the environment, nature conservation, building and nuclear safety (BMUB) said in a statement.
The statement came after the German Reactor Safety Commission (Reaktorsicherheitskommission, or RSK) – an independent expert group of the BMUB – said it could not confirm that the two PWRs are safe. RSK said this was the result of discussions with Belgian nuclear safety experts.
According to the minister, Barbara Hendricks, taking the reactors offline would be a “strong sign of precaution” and would show that Belgium “takes the worries of its German neighbour seriously”.
A newly formed Belgian-German bilateral expert group met on 5 and 6 April to discuss the issue of hydrogen flakes found in the wall material of the Tihange-2 and Doel-3 reactor pressure vessels (RPVs), the BMUB said.
Tihange-2 and Doel-3 were shut down in 2012 after the RPV flaws were discovered. In June 2013 the units were restarted, but were shut down again in March 2014 after unexpected results from additional tests.
In May 2015, operator Electrabel postponed the restart of the units following an announcement by the Belgian Federal Agency for Nuclear Control (Fanc) that it would take “several months” to analyse the safety case put forward by Electrabel related to the hydrogen flakes.
Fanc said at the time that it had submitted the results of tests on the RPVs to “numerous national and international experts”, including Oak Ridge National Laboratory in the US. It said it had gathered and analysed the reports and opinions to consolidate its own conclusions.
In November 2015, Fanc authorised the restart of both Tihange-2 and Doel-3 based on satisfactory results from structural assessments. Tihange-2 was restarted on 14 December 2015 and Doel-3 on 22 December 2015.
As a result of the April bilateral meeting, the BMUB said initial proposals for further testing of the two reactors have already been drawn up by the Belgian side. The BMUB said the German ministry welcomed this initiative and was willing to support the inspection programme.
In response to the comments made by Ms Hendricks, Fanc said today it was “surprised to learn” of Germany’s calls to shut down Tihange-2 and Doel-3.
According to Fanc, points raised by the German side during the April bilateral meeting “did not compromise” Belgium’s point of view and Fanc “remains convinced” that the two reactors comply with international safety standards, making a shutdown unnecessary.
Fanc said it hosted a two-day workshop on the RPV problem in Brussels in January 2016 for its foreign safety authority counterparts. All questions raised by German delegates received a written answer in February 2016, Fanc said.
Jan Bens, Fanc’s director-general, said German experts asked many questions during the April bilateral meeting, but did not raise any new issues which Fanc might have failed to take into account during the Tihange-2 and Doel-3 review process.
Based on a collection of “objective data”, test results, reports and opinions from various international experts and laboratories, Fanc said it is “convinced” that the two reactors are safe for operation despite the presence of hydrogen flakes in the RPV walls.
Fanc said it is willing to organise further cooperation initiatives with its German counterparts if they “are willing to collaborate in a constructive fashion”.
There are seven reactor units in commercial operation in Belgium, four at Doel and three at Tihange. Together, they generate about 55 percent of the country’s electricity.