China's Ministry of Ecology & Environment (MEE) said on 16 June that there had been no leak at the Taishan NPP in Guangdong Province and rejected allegations by CNN that the National Nuclear Safety Administration (NNSA) had raised the permitted radiation levels near the plant. NNSA had reviewed specifications for noble gases used in the reactor coolant at Taishan, but this had "nothing to do with the detection of any radiation outside the nuclear plant”, MEE said.
An increase in radiation levels had been detected in the primary circuit at unit 1 of the Taishan plant, but was within the parameters for safe operations. The increase was caused by damage to the cladding in a small number of fuel rods, which is normal during the production, transportation and loading of fuel, MEE noted on its WeChat social media account. "Environmental monitoring in the vicinity of the Taishan plant found no abnormal parameters ... showing no leak has occurred at all," the Ministry affirmed. It estimated that around five of more than 60,000 fuel rods in the Taishan 1 reactor core had been damaged, amounting to less than 0.01% of the total, far below the maximum design level of 0.25%.
The Ministry added that it will closely monitor radioactivity levels at the reactor and also maintain communications with the International Atomic Energy Agency (IAEA) as well as France's regulator.
IAEA said on 16 June that the China Atomic Energy Authority (CAEA) had p[rovided an “about an issue at the Taishan Nuclear Power Plant”. CAEA said the plant is in normal condition and that operational safety is guaranteed. Unit 1 of the plant recently experienced a minor fuel rod cladding failure, which resulted in increased radioactivity in the unit’s primary reactor coolant, it said. CAEA said that this situation, as a common phenomenon in NPP operations, is dealt with in accordance with accepted standards and procedures. According to on-site monitoring and an expert assessment, the unit’s performance indicators, including the radioactivity of the primary reactor coolant, remain within the range of normal conditions and technical specifications, CAEA said. It also said the reactor unit’s coolant system pressure boundary is intact and that containment integrity is maintained. Continuous environmental radiation monitoring confirms that there has been no radiation release and that there is no environmental concern, CAEA said. The IAEA said it remains in contact with CAEA.
Two days earlier, Framatome said it was “supporting resolution of a performance issue with the Taishan Nuclear Power Plant” but that “according to the data available, the plant is operating within the safety parameters”, adding: “Our team is working with relevant experts to assess the situation and propose solutions to address any potential issue.” The same day, EDF said it had “been informed of the increase in the concentration of certain noble gases in the primary circuit of reactor 1 of the Taishan nuclear power plant, belonging to and operated by TNPJVC, a joint-venture of CGN (70%) and EDF (30%)”. It added: “The presence of certain noble gases in the primary circuit is a known phenomenon, studied and provided for in the reactor operating procedures.” EDF requested an extraordinary TNPJVC board of directors meeting “for management to present all the data and the necessary decisions”. An EDF spokesman told Reuters that the build-up of inert gases at EPR reactor seemed to be due to issue with some fuel rods but that measurements were below maximum levels authorised in China.
These statements were prompted by a CNN alleging report that Framatome had contacted the US Department of Energy (DOE) concerning a "potential issue" at the Taishan plant. The two 1750MWe EPR units at the Taishan plant (1&2) are the first two reactors based on the EPR design to begin operation. Their construction followed a €8.0 billion ($9.7bn) contract signed by Areva and China General Nuclear Power Corporation (CGN) in November 2007. The Taishan project is owned by TNPJVC and Chinese utility Guangdong Energy Group (19%). Unit 1 began construction in 2009, and unit 2 in 2010. They entered commercial operation in December 2018 and September 2019, respectively. The EPR design used in Taishan was developed by Framatome.
CNN had reported that Framatome had warned DOE of an “imminent radiological threat” and accused NNSA of raising acceptable limits for radiation outside the plant to avoid having to shut it down. The report prompted a flurry of alarmist press reports worldwide and a series of discussions within the US administration, at the end of which a US official told CNN that the administration did not think the facility was at "crisis level". Citing a “source familiar with the situation”, CNN concluded: “While there is a chance the situation could become a disaster, US officials currently believe it is more likely that it will not become one”.
On 16 June, NNSA’s South China Nuclear and Radiation Safety Supervision Station said on 9 June it had carried out a "Nuclear Safety Culture Promotion Team" activity at Taishan to “maintain integrity and innovate, and jointly build a strong nuclear safety defence line. It noted: “Nuclear safety is the cornerstone and lifeblood of the operation of nuclear power plants, and every staff member directly related to safety and quality is a guardian of nuclear safety.”
Image: Taishan nuclear power plant (Credit: EDF)