French nuclear regulators have approved Areva’s proposed program of tests to investigate the mechanical properties of the vessel head and vessel bottom of Flamanville 3’s reactor pressure vessel.
The ASN (Autorité de Sûreté Nucléaire) said yesterday that it considered Areva’s proposed testing program to be “acceptable in principle” and had no objections to the start of the new series of tests.
The ASN released information in April about the discovery of anomalies in the composition of the steel in certain parts of the reactor vessel of the EPR under construction at Flamanville. The anomalies related to zones of high carbon concentration, which can affect the mechanical properties of the material. Both affected components – the vessel head and the vessel bottom – were manufactured at Areva’s Chalon/Saint-Marcel plant in France.
Areva notified ASN of its proposed approach to demonstrate that the material used in the components is mechanically adequate in May. The program will involve a series of mechanical and chemical tests.
ASN said it has based its decision on the opinion and recommendations from the Permanent Expert Group for nuclear pressure vessels (GP ESPN).
The results of the testing program will be an essential consideration for ASN in its decision making about the fitness for service of the affected components, the regulator said. The tests will take several months to complete.
Source: World Nuclear News