20 May (NucNet): Belgium’s nuclear safety regulator has given approval for GDF Suez to restart two nuclear reactors closed last year over safety concerns, it said in a statement.
The Federal Agency for Nuclear Control (FANC) said it considers that Doel-3 and Tihange-2, both pressurised water reactor units, can be restarted safely.
The statement added that all of the safety concerns had been resolved satisfactorily “after a thorough review” of safety case documents provided by operator Electrabel, a subsidiary of France’s GDF Suez.
In January 2013, FANC formulated 11 requirements that had to be fulfilled before a possible restart, as well as five “post-restart requirements” covering five areas: in-service ultrasonic inspection techniques; the origin and evolution of the flaws; the characterisation of material properties; the structural integrity of the reactor pressure vessels (RPVs); and load tests.
Checks were carried out on the two units after indications of flaws were found in the units’ RPVs in 2012 using an improved testing technology.
The flaws in the Doel-3 RPV were originally suspected in August 2012 and at that point the unit was shut down for inspection.
As a precaution, Belgium’s six other commercially operational reactors were also checked for RPV flaws. In September 2012, FANC said there were indications of similar flaws in the Tihange-2 RPV, but not in any other reactors.
In December 2012, Electrabel said results of tests carried out to confirm the structural integrity of the reactors showed that both were safe for immediate restart and operation.
The company said the tests demonstrated that the RPVs’ structural integrity meets “within significant margins” all safety criteria. The investigations and calculations carried out were subjected to “a stringent control procedure” that was validated by outside experts, Electrabel said.
However, FANC decided that while tests showed nothing that would require a permanent shutdown of the units, supplementary tests were needed.
Doel-3 is scheduled to be decommissioned in 2022 and Belgium plans to close all its nuclear power stations by 2025.
There are seven reactor units in commercial operation in Belgium: four at Doel and three at Tihange. Together, they generate about 55 percent of the country’s electricity.
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