Belgian utility Electrabel has extended the period of unavailability of Doel 3 and Tihange 2 to November 2015. The plant operator had previously said the reactors might be able to return to service in July.
Electrabel said its update follows information from the Federal Agency for Nuclear Control, which together with its technical subsidiary Bel V, AIB Vincotte, and International Review Board and an external research team is analysing the safety case for reactor vessels of Doel 3 and Tihange 2.
A panel of international experts of the IRB met for three days in April and discussed the results of mechanical tests were carried out on specimens containing hydrogen flakes that had been previously irradiated in the BR2 research reactor. The board is now expected to issue an opinion on the methodology that must be used by the licensee Electrabel to write this specific chapter of its Safety Case.
FANC said it would gather opinions from IRB and the other parties and take them into account to decide whether Electrabel is allowed to restart the Doel 3 and Tihange 2 units. The process is expected to take another few months. As a result, Electrabel considers that the period of unavailability has to be reviewed.
Both Doel 3 and Tihange 2 have been offline since March 2014, after inspections revealed thousands of tiny flaws in the steel of the reactor pressure vessels. The regulator ordered further investigations, including irradiation of similar material. Electrabel says that to date more than 1500 tests have been carried out, involving 100 people.