nuclear-news

French Nuclear regulator requires more inspections of Flamanville EPR reactor pressure vessel anomaly.

ASN 28th June 2017, On 28th June 2017, ASN presented its position regarding the Flamanville EPR
reactor pressure vessel anomaly. ASN relied on the analysis of the files
transmitted by Areva NP and EDF, carried out by its nuclear pressure
equipment department and its technical support organisation IRSN, and on
the opinion of its Advisory Committee for nuclear pressure equipment.

On the basis of the technical analyses carried out, ASN considers that the
mechanical characteristics of the pressure vessel bottom head and closure
head are adequate with regard to the loadings to which these parts are
subjected, including accident situations.

However, the anomaly in the chemical composition of the steel entails a reduction in the margins with
respect to the fast fracture risk. ASN therefore considers that EDF must
implement additional periodic inspections to ensure that no flaws appear
subsequently. ASN observes that such inspections can be performed on the
vessel bottom head and therefore considers that they must be implemented.

However, the technical feasibility of similar inspections on the pressure
vessel closure head is not established. ASN therefore considers that the
use of the closure head must be limited in time. It notes that it would
take about seven years to manufacture a new closure head, which could thus
be available by the end of 2024. In these conditions, ASN considers that
the current closure head shall not be operated beyond that date.
http://www.french-nuclear-safety.fr/Information/News-releases/ASN-presents-its-position-regarding-the-Flamanville-EPR-reactor-vessel-anomaly

June 30, 2017 - Posted by Christina Macpherson | France, safety