line in the emergency cooling system
Largest crack discovered on nuclear power plant in France
03/08/2023, 7:09 p.m
A crack in a French nuclear power plant is causing concern for operators, regulators and experts. In the Penly kiln on the English Channel, a line of the emergency cooling system is badly damaged. A level 2 incident is declared.
The largest corrosion damage discovered to date in a French nuclear reactor is likely to prompt thorough inspections of other nuclear power plants. The French nuclear safety authority asked the power plant operator EDF to “detect possible further cases” and “adjust its control strategy”.
The regulator announced last night that EDF had discovered an unusually long and deep crack in a pipe at the Penly nuclear power station on the English Channel, which went on stream in 1992. It is therefore a 15.5 centimeter long crack, which corresponds to a quarter of the diameter of the line. It is also 23 millimeters deep with a tube thickness of 27 millimeters. “It’s not a hairline crack (…), it’s a problem,” said agency chief Bernard Doroszczuk at a Senate hearing.
“Because of the possible consequences and the increased probability of a rupture,” the authority classified the rupture as an accident at level two on the INES scale for evaluating nuclear events. This does not endanger people or the environment. Level two incidents are relatively rare, there was just one in the past year.
“Almost a leak”
The reactor is currently shut down. It should be ramped up again in May. “The crack appeared in a place where you didn’t expect it,” said nuclear expert Yves Marignac. It is a line in the emergency cooling system through which heated water is routed in an emergency.
So far, EDF has primarily checked the lines of the emergency cooling system, through which cold water would be fed, Marignac said. The extent of the crack is worrying. “It’s almost a leak,” he said.
According to the Nuclear Safety Authority, the crack is due to an error in the construction of the nuclear power plant. “People bent the pipes to weld them, then the welds had defects and they were repaired again,” explained Doroszczuk. This is an “unacceptable course of action”.
Not the first crack
Since the end of 2021, fine cracks up to six millimeters deep have appeared in pipelines in several newer nuclear power plants in France. EDF had taken part of the reactors off the grid because of the necessary repair work. The repairs were delayed because France lacked the necessary specialists. All 56 reactors should be examined for possible corrosion damage. EDF announced at the end of last year that it had overcome the corrosion damage crisis.
According to the Nuclear Safety Agency, EDF has now also updated its information on corrosion problems in nuclear reactors in Cattenom, Civaux and Chooz. These were rated level one as “disorder” by the agency on the INES scale. Details on this are not yet known.
Due to ongoing problems with its aging nuclear park, France produced less electricity last year than it had in three decades. President Emmanuel Macron wants to lay the foundation stone for the first two of six new nuclear reactors that are to be built in Penly during his term in office.