3 Sep (NucNet): The cause of a small leak in the emergency cooling water circuit of the Doel-1 nuclear power reactor in Belgium has not yet been determined and the unit will remain offline until tests and repairs are concluded, the nuclear regulator said.
The Federal Agency for Nuclear Control (Fanc) said inspections and pipe replacement work would also be carried out on the Doel-2 plant, which has been shut down for the checks.
“The cause of this event has not yet been determined and no conclusion can be drawn for the moment,” Fanc said. “Operations to replace the part of the pipe concerned are being prepared.”
Fanc said operator Engie-Electrabel has removed the part of the pipe from Doel-1 and is carrying out analysis in a laboratory.
Doel-1 and Doel-2 are both 433-MW pressurised water reactor units. The other two units at the Doel site, Doel-3 and Doel-4, are different models of power reactor and are not affected by the problem.
In April 2018, Engie-Electrabel pinpointed the source of the leak using an endoscope. It was caused by a crack in a weld on a reserve line connected to the primary circuit that serves to feed the reactor with cooling fluid in certain emergency situations.
In May 2018 Engie-Electrabel said the leak was “a few litres per minute”. However, the leak is in a difficult location for repairs and the company said at the time that Doel-1 was likely to be offline until 1 October 2018.
Fanc said the incident had been classified as Level 0 on the International Atomic Energy Agency’s International Nuclear and Radiological Event Scale. Level 0 on the seven-level scale means the incident was a “below scale” event of no safety significance.
Fanc said Engie-Electrabel will need its approval to restart the units.
