World February 17, 2015 | 12:01 pm

Thousands more cracks found in Belgian nuclear reactors

Brussels.– Following the discovery of thousands of additional cracks in critical components of two Belgian nuclear reactors, Greenpeace today called for immediate checks of nuclear power plants worldwide.

The cracks were found in the steel nuclear reactor pressure vessels in nuclear reactors Doel 3 and Tihange 2 in Belgium. The vessels contain highly radioactive nuclear fuel cores. The failure of these components can cause catastrophic nuclear accidents. On February 13th, two leading material scientists announced that the pervasive and unexpected cracking could be related to corrosion from normal operation, with potential implications for reactors worldwide.

Greenpeace Belgium energy campaigner, Eloi Glorieux, said: “What we are seeing in Belgium is potentially devastating for nuclear reactors globally due to the increased risk of a catastrophic failure. Nuclear regulators worldwide must require reactor inspections as soon as possible, and no later than the next scheduled maintenance shutdown. If damage is discovered, the reactors must remain shut down until and unless safety and pressure vessel integrity can be guaranteed. The nuclear industry, already in crisis, is faced with an ageing nuclear reactor fleet at increasing risk of severe disaster.”

In reaction to the findings, the Director-General of the Belgian nuclear regulator of the Federal Agency for Nuclear Control (FANC), Jan Bens, has said that this could be a problem for the entire nuclear industry globally. He added that the solution is to begin the careful inspection of 430 nuclear power plants worldwide.

The problem was initially discovered in the summer of 2012. Both the Doel 3 and Tihange 2 reactors have been shut down since March 24th, 2014 after additional tests revealed an unexplained advanced embrittlement of the steel of the test sample. The integrity of the pressure vessel must be absolute due to the radioactive releases that would result if this component were to fail.

As nuclear reactors age, radiation causes pressure vessel damage, or embrittlement, of the steel. According to the statements of the two materials scientists on Feb 13th, the damage in the Belgian reactors may be partially caused by a problem resulting from the migration of hydrogen into cracks in the steel liner of the vessel – exacerbating and expanding that cracking. The phenomenon is like a road in winter where water trickles into tiny cracks, freezes, and expands, breaking up the road; it appears that hydrogen from the water within the vessel that cools the reactor core is getting inside the liner, reacting, and destroying the pressure vessel from within.

FANC has subsequently issued a statement confirming that the additional tests conducted in 2014 revealed 13,047 cracks in Doel 3 and 3,149 in Tihange 2. On February 15th the nuclear reactor operator, Electrabel (GDF/Suez parent company) announced that it would be prepared to ‘sacrifice’ one of its reactors to conduct further destructive tests of the reactor pressure vessel in order to study this poorly understood and extremely concerning damage phenomenon.

In 2012, the operator of the reactors, Electrabel, dismissed the cracks as being the result of manufacturing problems during construction in the late 1970’s in the Netherlands, but still failed to table evidence for this assumption. The Belgian regulator also stated that the most likely cause was manufacturing – but could not prove it and added that it may be due to other causes.

The recent announcements of the materials scientists, whose concerns were echoed by Director-General Bens, indicate that this problem could be far beyond manufacturing. If confirmed, it means that the safety of every nuclear reactor on the planet could be significantly compromised.

There are 435 commercial nuclear reactors worldwide, with an average age of 28.5 years in mid 2014. Of these, 170 reactors (44 percent of the total) have been operating for 30 years or more and 39 reactors have operated for over 40 years.

As of 2015, Doel 3 has been operating for 33 years; Tihange 2 for 32 years.

“As we approach the fourth anniversary of the Fukushima-daiichi nuclear disaster, evidence has emerged that demands immediate action to prevent another catastrophe. Thousands of previously unknown cracks in critical components of two reactors point to a potentially endemic and significant safety problem for reactors globally. Continuing to operate any reactor with such cracking would be an absolutely unacceptable risk to public safety. Greenpeace demands detailed inspections of all nuclear reactors worldwide, as conducted in Belgium, and the public release and scrutiny of the results. Any reactor with such cracking must be kept offline, until and unless the cracking is understood and safety is guaranteed. Anything less would be insane given the risk of a severe nuclear accident,” continued Glorieux.

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