Steel supplied by Japanese manufacturers to the French nuclear program have been found to have carbon contents outside regulatory limits, with major implications for nuclear safety, including reduced toughness of the steel and increased risk of catastrophic failure. Greenpeace Japan released a report from an independent nuclear engineer last week that detailed some of the implications for the Japanese reactor fleet if it was found that there was excess carbon found in reactor pressure vessels and steam generators. “The nuclear industry in France is now in crisis as a result of the carbon test results, with 11 reactors supplied by Japanese steel ordered shutdown and under investigation by the regulator. The Japanese nuclear industry is desperate to shut the door on this issue and avoid a repeat of what is happening in France. However, it was only after the French regulator ordered non destructive and destructive testing that the true scale of the excess carbon problem was confirmed. No such testing has been done in Japan. None of the documentation released by the utilities demonstrates what the carbon concentration is in the actual installed components. And until actual testing is conducted, the NRA, and more importantly the communities living near nuclear reactors, will not know what risks the nuclear plants pose. The NRA cannot allow this to be a paper exercise on the part of the utilities. The NRA must instruct utilities to undertake non destructive and destructive testing as a matter of urgency, the priority being the Sendai-2 and Ikata-3 reactors which are the only operating plants,” said Shaun Burnie, nuclear specialist at Greenpeace Germany. Steel under investigation in the French nuclear reactor program was supplied by Japan Casting and Forging Company and Japan Steel Works. Both supplied the steel for Japanese reactors, together with JFE. The AREVA owned le Creusot steel forge is also under investigation.
Greenpeace 1st Nov 2016 read more »
The discovery of widespread carbon segregation problems in critical nuclear plant components has crippled the French power industry—20 of the country’s 58 reactors are currently offline and under heavy scrutiny. France’s nuclear safety chairman said more anomalies “will likely be found,” as the extent of the contagion is still being uncovered. With over half of France’s 58 reactors possibly affected by “carbon segregation,” the nation’s nuclear watchdog, the Autorité de Sûreté Nucléaire (ASN) has ordered that preventative measures be taken immediately to ensure public safety. As this story goes into production in late October, ASN has confirmed that 20 reactors are currently offline and potentially more will shut down in coming weeks. The massive outages are draining power from all over Europe. Worse, new questions continue to swirl about both the safety and integrity of Électricité de France SA’s (EDF’s) nuclear fleet, as well as the quality of some French- and Japanese-made components that EDF is using in various high-profile nuclear projects around the world. Excessive levels of carbon in the steel parts could make them more brittle and subject to sudden fracture or tearing under sustained high pressure, which is obviously unacceptable. Initially discovered at the troubled 1.65-GW Flamanville 3 project (Figure 1) in 2014—one of the first in the vaunted European Pressurized Reactor (EPR) nuclear plant series that EDF also plans to use at the newly approved Hinkley Point C plant in England—more flaws have since been discovered throughout the existing nuclear fleet. According to an ASN press relation’s officer, who requested anonymity in line with ASN rules, there are now a significant number of reactors offline, with more to be inspected in the next few weeks. “We are now finding carbon segregation problems from components coming from both Le Creusot and [the Kitakyushu-based Japan Casting & Forging Corp.] JCFC plant. As for now, there [are] 20 EDF reactors offline,” the official said, noting that the number will fluctuate as inspections take place.
Power Mag 1st Nov 2016 read more »