— France’s nuclear power stations ‘at risk of catastrophic failure’ — Sizewell B and 27 other EDF nuclear plants

Global Research, October 01, 2016
The Ecologist 29 September 2016
tumblr_lvqjar7N5n1qiypiuo1_500

A new review of the safety of France’s nuclear power stations has found that at least 18 of EDF’s units are are ”operating at risk of major accident due to carbon anomalies.”

The review was carried out at the request of Greenpeace France following the discovery of serious metallurgical flaws by French regulators in a reactor vessel at Flamanville, where an EPR plant is under construction.

The problem is that parts of the vessel and its cap contain high levels of carbon, making the metal brittle and potentially subject to catastrophic failure. These key components were provided by French nuclear engineering firm Areva, and forged at its Le Creusot.

“The nature of the flaw in the steel, an excess of carbon, reduces steel toughness and renders the components vulnerable to fast fracture and catastrophic failure putting the NPP at risk of a major radioactive release to the environment”, says nuclear safety expert John Large, whose consultancy Large Associates (LA) carried out the Review.

His report examines how the defects in the Flamanville EPR reactor pressure vessel came about during the manufacturing process, and escaped detection for years after forging. It then goes on to investigate what other safety-critical nuclear components might be suffering from the same defects.

Steam generators at 28 EDF nuclear sites at risk

After several months of investigation LA found that critical components of a further 28 nuclear plants were forged by Le Creusot using the same process. These are found in the steam generators – large, pod-like boilers – that have been installed at operational EDF nuclear power stations across France.

The conclusion is based on documents provided by IRSN (the independent French Institut de Radioprotection et de Sûreté Nucléaire) that reject assurances given by both EDF and Areva that there is no safety risk from steam generators containing the excess carbon flaw.

In August 2016, IRSN warned the French nuclear safety regulator Autorité de Sûreté Nucléaire (ASN) that:

  • EdF’s submission was incomplete;
  • there is a risk of abrupt rupture which could lead to a reactor core fuel melt; and
  • immediate “compensatory” measures need to be put in place to safeguard the operational NPPs involved.

“As a result of Areva’s failures, a significant share of the French nuclear reactor fleet is at increased risk of severe radiological accident, including fuel core meltdown”, said Large. ”However, there is no simple or quick fix to this problem.

“The testing and inspection regime currently underway by Areva and EDF is incapable of detecting the extent and severity of the carbon problem and, moreover, it cannot ensure against the risk of rapid component failure. It is most certain that the IRSN finding will equally applies to replacement steam generators exported by Areva to overseas nuclear power plants around the world.”

EDF reactors face protracted closure, credit rating falls

EDF stated yesterday that it will carry out further tests on 12 nuclear reactors during their planned outages in the coming months – and that extended periods of outage are to be expected. “There are outages that could take longer than planned”, an EDF spokesman told Reuters.

“In 2015, we discovered the phenomenon of carbon segregation in the Flammanville EPR reactor. We decided to verify other equipments in the French nuclear park to make sure that other components are not impacted by the phenomenon.”

In anticipation of the nuclear closures, year-ahead electricity prices rose in the French wholesale power market, forcing power rises across Europe up to a one-year high.

Meanwhile Moody’s has downgraded EDF credit ratings across a spectrum of credit instruments. EDF’s long-term issuer and senior unsecured ratings fell from A2 to A3 while perpetual junior subordinated debt ratings fell to Baa3 from Baa2. Moody’s also  downgraded the group’s short-term ratings to Prime-2 from Prime-1.

According to Moody’s,

“the rating downgrade reflects its view that the action plan announced by EDF in April 2016, which includes government support, will not be sufficient to fully offset the adverse impact of the incremental risks associated the Hinkley Point C (HPC) project on the group’s credit profile.

“Moody’s believes that the significant scale and complexity of the HPC project will affect the group’s business and financial risk profiles. This is because the HPC project will expose EDF and its partner China General Nuclear Power Corporation (CGN, A3 negative) to significant construction risk as the plant will use the same European Pressurised reactor (EPR) technology that has been linked with material cost overruns and delays at Flamanville in France and Olkiluoto 3 in Finland. In addition, none of the four plants using the EPR technology currently constructed globally is operational yet.”

Once rating agencies have had time to evaluate the seriousness of EDF’s current problems with reactors packed with unsafe crirical components, further downgrades may follow. “The ratings could be downgraded if (1) credit metrics fall below Moody’s guidance for the A3 rating; or (2) EDF were to be significantly exposed to AREVA NP’s liabilities”, the agency warns.

Flamanville EPR heading for the scrapheap

The Review also shows that the reactor pressure vessel of the Flamanville EPR, which is already installed, does not have a Certificate of Conformity issued by ASN. This means that it does not comply with the European Directive on Pressure Equipment, nor does it meet the mandatory requirement of the ASN, which since 2008, stipulates that any new nuclear reactor coolant circuit component has to have a Certificate of Conformity before its production commences.

“Without a Certificate of Conformity the reactor pressure vessel and steam generators currently installed in Flamanville 3 will almost certainly have to be scrapped”, said Roger Spautz, responsible for nuclear campaign at Greenpeace France.

The review, he added, ”reveals evidence that at the Creusot Forge plant, Areva did not have the technical qualifications required to meet exacting nuclear safety standards. The plant was not under effective control and therefore had not mastered the necessary procedures for maintaining the exacting standards for quality control in the manufacture of safety-critical nuclear components.”

Areva has now acknowledged that ineffective quality controls at le Creusot Forge were mainly responsible not only for the flaws in the Flamanvile 3 EPR, but across other operational nuclear power plans – and that the technical failures date back to 1965.

Moreover, ASN has indicated that in the nuclear components supply chain three examples of Counterfeit, Fraudulent and Substandard Items (CFSI) have occurred in the year ending 2015.

The recent ASN publication (24th September 2016) of a list of the NPPs affected by the AREVA anomalies and irregularities demonstrates that the phenomenon not only has reached alarming proportions but is continuing to grow under scrutiny.

The number of components affected by irregularities and installed in NPPs in operation increased by 50 in April 2016 from 33 to 83 by 24th September this year. Irregularities affecting the Flamanville EPR increased from two to 20 over the same period.

Also at risk: Sizewell B, Hinkley C finance, Taishan EPRs

LA’s Review also relates these developments in France to the UK, specifically: the currently operating Sizewell B NPP in Suffolk; and the now contracted construction programme for the Hinkley Point C NPP.

Sizewell B which includes a number of components sourced from Le Creusot which need urgent examination and / or replacement in order to prevent unsafe operation. The fact that this could escape the UK’s nuclear regulators also indicates, says Large, that “the Office for Nuclear Regulation (ONR) did not delve deep enough into the situation as now revealed by ASN.”

As for For Hinkley Point C, it now appears inevitable that the Flamanville reactor will not be completeted by its target date of the end of 2020, indeed it may very well never be completed at all. Under the terms of agreement for the plant’s construction accepted by the European Commission, this would render the UK government unable to extend promised credit guarantees to HPC’s financial backers.

“Now that ASN has deprioritized efforts on the under-construction Flamanville 3 NPP because of its pressing urgency to evaluate the risk situation for the operating NPPs”, says Large, ”there is a greater likelihood that Flamanville 3 will not reach the deadline for operation and validation of its technology by the UK Credit Guarantee cut-off date of December 2020.”

Also at risk are the two EPRs that Areva and EDF are currently constructing at Taishan in China. These are now at the most advanced stage of any EPR projects in the world, however there are increasing fears that they contain faulty components.

The vessels and domes at Taishan were also supplied by Areva, and manufactured by the same process as that utilised by Le Creusot. It is suspected that Chinese nuclear regulators may have decided to overlook this problem and hope for the best. However if they discover that the steam generators, which along with the reactor vessels have already been installed, are also at risk of catastrophic failure, that might prove a risk too far – even for China.

The danger for EDF and Areva is that the massive commercial liabilities they may be accruing for faulty reactors supplied to third parties, together with the tens of billions of euros of capital write-downs for projects they have to abandon, and the loss of generation revenues due to plant outages, could easily exceed their entire market capitalisation.

In other words: for EDF, Areva, their shareholders and the entire French nuclear industry, the end really could be nigh.

Oliver Tickell is contributing editor at The Ecologist.

Advertisements

Belgian nuclear reactors riddled with 16,000 unexplained cracks

From the Ecologist
by Oliver Tickell
18th February 2015

The discovery of over 16,000 cracks in two Belgian reactor vessels may have global implications for nuclear safety, says the country’s nuclear safety chief. He and independent experts are calling for the immediate checks of nuclear reactor vessels worldwide.

The safety of every nuclear reactor on the planet could be significantly compromised … What we are seeing in Belgium is potentially devastating for nuclear reactors globally due to the increased risk of a catastrophic failure.

Thousands of cracks have been found in the steel reactor pressure vessels in nuclear reactors Doel 3 and Tihange 2 in Belgium – vessels contain highly radioactive nuclear fuel cores.

The failure of these components can cause catastrophic nuclear accidents with massive release of radiation.

The pervasive – and entirely unexpected – cracking could be related to corrosion from normal operation, according to leading material scientists Professor Walter Bogaerts and Professor Digby MacDonald.

Speaking on Belgian TV, Professor MacDonald said:

“The consequences could be very severe … like fracturing the pressure vessel, loss of coolant accident. This would be a leak before break scenario, in which case before a fracture of a pipe occurred … you would see a jet of steam coming out through the insulation.

“My advice is that all reactor operators, under the guidance of the regulatory commissions should be required to do an ultrasonic survey of the pressure vessels. All of them.”

Professor Bogaerts added:

“If I had to estimate, I would really be surprised if it … had occurred nowhere else … I am afraid that the corrosion aspects have been underestimated.”

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

An unexplained embrittlement

The problem was 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.

At the time the reactors’ operator, Electrabel, dismissed the cracks as being the result of manufacturing problems during construction in the late 1970’s in the Netherlands – but provided no supporting evidence.

FANC also stated that the most likely cause was manufacturing – but added that it could be due to other causes. Following the further tests FANC has now issued a statement confirming that the additional 2014 tests revealed 13,047 cracks in Doel 3 and 3,149 in Tihange 2.

“In carrying out tests related to theme 2 during the spring of 2014, a fracture toughness test revealed unexpected results, which suggested that the mechanical properties of the material were more strongly influenced by radiation than experts had expected. As a precaution both reactors were immediately shut down again.”

As nuclear reactors age, radiation causes pressure vessel damage, or embrittlement, of the steel mostly as a result of the constant irradiation by neutrons which gradually destroys the metal atom by atom – inducing radioactivity and transmutation into other elements.

Another problem is that hydrogen from cooling water can migrate into reactor vessel cracks. “The phenomenon is like a road in winter where water trickles into tiny cracks, freezes, and expands, breaking up the road”, says Greenpeace Belgium energy campaigner Eloi Glorieux.

“It appears that hydrogen from the water within the vessel that cools the reactor core is getting inside the steel, reacting, and destroying the pressure vessel from within.”

He adds that the findings mean that “the safety of every nuclear reactor on the planet could be significantly compromised … What we are seeing in Belgium is potentially devastating for nuclear reactors globally due to the increased risk of a catastrophic failure.”

Immediate action needed to prevent another catastrophe

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.

Electrabel’s findings will be submitted to FANC which will organize a new meeting of the international panel of experts to obtain their advice on the results of the new material tests and on the new data.

According to Electrabel, the findings constitute a “Level 1 occurrence on the International Nuclear Event Scale (INES)” but the company emphasises that the event “has no impact whatsoever on the wellbeing or health of the employees, the local residents, or the surrounding area.”

But Glorieux dismisses such complacency:

“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.

“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. Anything less would be insane given the risk of a severe nuclear accident”

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.

Oliver Tickell edits The Ecologist.

http://www.theecologist.org/News/news_round_up/2758982/belgian_nuclear_reactors_riddled_wi%20th_16000_unexplained_cracks.html