Taishan Nuclear Power Plant

Taishan nuclear power plant is near the coast in Guangdong Province in China. That’s about 60km west of Macau, and about 120km west of Hong Kong. It is 50km south of Taishan itself, a city with a population of 500,000.

On about the 15th June, various news sources reported on an incident at the plant. Fuel rods were damaged and gas released. The suggestion was that the gas was released as a way to deal with the problem. Or perhaps the release or escape of the gas was as part of the problem.

A New York Times article of 16th June states that “Nuclear scientists in the United States and Europe said in interviews this week that a buildup of radioactive gas in the water surrounding the fuel rods, while not uncommon at reactors elsewhere, was often a sign of poor design, manufacturing or management.”

Given the context, that comment at least raises the possibility that poor design, manufacturing or management is widespread worldwide.

That aside, which way do the prevailing winds blow in that part of Guangdong? An article as recent as the 13 May in the journal Nature states that “The region is influenced by the East Asian monsoon system, which is characterized by prevailing northeasterly and southwesterly winds in winter and summer, respectively.”

So if there was a major problem at this time of year, the wind would carry towards Macau and Hong Kong.

Update 20 June 2021

On 17 June, The International Atomic Energy Agency (IAEA) reported that “The China Atomic Energy Authority (CAEA) informed the IAEA yesterday that a minor fuel cladding failure  had occurred at the Taishan Nuclear Power Plant.”

The article goes on to explain that cladding failures are not uncommon. But it doesn’t explain what the cladding is beyond the obvious that it clads the fuel rods.

The glossary in the United States Nuclear Regulatory Commission website (US.NRC) states that cladding is “The thin-walled metal tube that forms the outer jacket of a nuclear fuel rod. It prevents corrosion of the fuel by the coolant and the release of fission products into the coolant. Aluminum, stainless steel, and zirconium alloys are common cladding materials.”

I guess that if the cladding is damaged then coolant can reach the fuel rods. If that happens, then the fuel rods can release fission products into the coolants.

I understand that Taishan has about 60,000 fuel rods in its construction. The reports state that ‘about’ five rods were damaged. Why don’t they know the exact number that were damaged?

What causes a cladding tube to fail? Is it a mechanical failure when it hits against something? Is it a chemical failure because the heat generated in the rod punctures it? And how much radioactive gas was released to deal with the problem?

Update 21 June 2021

A report on the incident on June 16 by Reuters mentioned that another incident was reported by the Chinese National Nuclear Safety Administration (NNSA) in April. A burst of radioactive gas unexpectedly entered a pipe at Unit 1’s waste gas treatment system just as workers were trying to seal it, triggering an alarm.

Several outlets report that a Zhang Zhijian, a professor at the College of Nuclear Science and Technology at Harbin Engineering University died in what is described as mysterious circumstances. He is reported to have fallen off a building at 9.34 am on June 17, 2021. It is inevitable that some news reports will see his death as linked to Taishan incident, whether that is the case or not. What strikes me is Harbin University reporting the time of death so precisely.

Update 30 July 2021

The Financial Times reported on 30 July that the French nuclear operator EDF had recommended that the reactor be shut down because of a build-up of inert gases in the primary water circuit.

Also on 30 July, China General Nuclear Power Corp (CGN) issued a statement on its website at cgnpc.com that after consultation they had shut down the reactor to find the cause of fuel damage, and replace the damaged fuel and that the reactor is safe and controllable.

The Sunday Times on 30 July reported that following an increase in radiation levels that had prompted warnings from its French designers of an “imminent radiological threat”, the authorities had shut down the reactor.