China Nuclear Plant Under Scrutiny Was Built to Showcase Nation’s Prowess

Its two reactors, which its owners say are the most powerful in the world, join 49 others that China has in operation. While the plant, its construction ridden with delays, took about a decade to enter commercial operation, the new-generation reactors boast improved fuel technology, greater thermal efficiency, and enhanced safety systems, making the project a linchpin of China’s efforts to reduce reliance on fossil fuels.

U.S. officials are monitoring the potential for accidents at the site, after the French co-owner, EDF, said it had requested a meeting with Chinese managers over the buildup of gases inside one of the plant’s reactors.

EDF said the plant was operating within safety parameters according to available data. Authorities in China and Hong Kong also said there have been no radioactive incidents threatening public safety or the environment.

China’s National Nuclear Safety Administration reported elevated background gamma radiation levels in the plant’s vicinity on Monday, in some cases nearly twice those at monitoring posts farther inland. However, such levels were similar to or lower than readings reported for stretches last year in China’s southeast, and crop up as well without incident in other parts of the world.

“You have to remember there is a certain amount of background radiation level,” said David Fishman, manager at energy-focused consulting firm Lantau Group. “Nothing I’ve seen so far is very concerning.”

The main theories of what might have happened at the plant, Mr. Fishman said, are a cracked fuel rod or perhaps a failed water seal, resulting in a small release of gas. “Either of those things are extremely, extremely minor events,” he added.

The Taishan Nuclear Power Joint Venture Co. said regulatory monitoring of environmental data at the plant and surroundings shows normal levels. China’s Foreign Ministry made similar comments Tuesday and cited the country’s strong nuclear-safety record to date.

In successive economic-development blueprints, Beijing has called for cuts to coal capacity, pivoting power production to cleaner resources such as natural gas, hydropower and wind power.

“China has shown unprecedented eagerness to achieve the world’s best standards in nuclear safety,” the London-based World Nuclear Association said in a June report, pointing to Beijing hosting operational safety review missions from the International Atomic Energy Agency, and forming information exchange networks with neighboring nations.

Beijing slowed its approval process to review safety standards in the wake of Japan’s 2011 Fukushima disaster. In a bid to improve the transparency of nuclear regulation, Chinese authorities conducted a rare invitation of public comment on its nuclear-safety plan, setting goals tailored to international standards to ensure no serious incident at its reactors.

Nuclear power remains the smallest piece of China’s energy resources by production, about 5% in 2020. But actual nuclear-power capacity has nearly quintupled in the last decade. China is the most active builder of nuclear reactors in the world, with some 11 more reactors under construction, according to the International Atomic Energy Agency.

China’s hunger for nuclear power remains a business driver for the companies that build the plants. In technology-transfer agreements that accompany such facilities, Chinese state research institutes and machinery companies have gradually learned to replicate the production of sensitive nuclear equipment, with the aim of limiting the scope of work for overseas component suppliers, analysts and executives say.

Framatome, the EDF subsidiary in the Taishan joint venture, at the project’s inception called it “quite simply the largest civil nuclear agreement in history.” It said the plant gave it “an even stronger foothold in China, one of the most promising markets.”

In the process, China has made strides toward attaining self-sufficiency in reactor design and construction, though it continues to use, adapt and improve Western technology, the World Nuclear Association said in a June report.

Framatome’s agreement with China, which gave EDF a 30% stake, comprises four components, including engineering, procurement, fuel core supply, and technological transfers, Framatome said.

Officials in Hong Kong, which gets most of its power from mainland China, said in an email that two notifications were received from mainland authorities on the Taishan plant separately in February and April. They related only to “Level 0 deviations,” meaning incidents that don’t affect the plant’s safe operation, workers’ health, members of the public, or the environment. Environmental radiation levels in Hong Kong have remained normal in the past year, officials said.

At some 154 nanograys per hour, a measure of gamma radiation, the level reported by China’s nuclear-safety association on Monday still is a tiny fraction of readings above 10,000 nGy/h around the Fukushima Daiichi plant in Japan in 2011.

Issues such as cracked fuel rods in nuclear plants “normally would be handled by client operational procedures without anyone even knowing anything had ever happened,” Mr. Fishman said. In this case, an application by Framatome to seek help from its U.S.-based colleagues drew media attention, he said.

Framatome sent a letter to the U.S. Department of Energy outlining unspecified issues relating to a potential incident at the plant, triggering discussions inside the U.S. administration. Framatome said it is “supporting resolution of a performance issue” with the Taishan nuclear power plant. It said the plant was operating within safety parameters according to available data.

—Alex Leary and Liyan Qi contributed to this article.

Write to Chuin-Wei Yap at [email protected]