EPR Reactor: Information Letter n°10: ASN continues inspections at the EPR Flamanville reactor construction site

Published on 10/02/2011 at 17:21

Information notice

During the second half of 2010, ASN continued its inspection activities at the Flamanville 3 EPR construction site.

Environmental inspection of the Flamanville 3 worksite

In conjunction with the DDTM[1] of the Manche department in the northwest of France, ASN performs environmental inspections at the Flamanville 3 worksite and verifies EDF’s compliance with provisions of the prefectorial order of 20 October 2006[2] which regulate water discharges and sampling at the worksite until the reactor goes into service. Several inspections are performed each year to this effect.

Thus, in 2010, several inspections by ASN confirmed that environmental management of the Flamanville 3 construction site is satisfactory. For example, the current organisation encourages enterprises at the worksite to limit water consumption and the risks of hydrocarbon pollution.

EDF has encouraged enterprises to work together to sort waste. ASN acknowledges the importance of this approach for maintaining a cleaning worksite but notes that it must nevertheless include strict identification of waste producers.

Assuming the reactor is commissioned, ASN decisions 2010-DC-0188 and 2010-DC-0189 will ultimately regulate water discharges and sampling from the Flamanville 3 reactor when it goes in operation.

Treatment of construction joints

In 2009, ASN observed construction joints[3] at the Flamanville 3 construction site whose surface roughness was inadequate and thus did not comply with ETC-C[4]. Use of a chemical product not specifically designed for treating construction joints was observed at the worksite: ASN required that its use be suspended in August 2009. At the same time, ASN requested EDF to perform further studies on the methods for treating construction joints.

EDF performed several tests on the treatments of construction joints and analysed the results. In November 2010, ASN and IRSN met with EDF so that it could present its conclusions on the testing.

The research confirms that the chemical treatment products for construction joints used today on the worksite result in concrete structures with satisfactory mechanical behaviour if they are applied in compliance with good engineering practice. ASN considers that the studies performed by EDF respond to the request made in 2009, but that they should be pursued to better take into account situations at the worksite, including difficulty with application and cleaning.

ASN is currently inspecting EDF’s organisation of training of future operating personnel at the Flamanville 3 nuclear reactor

EDF is responsible for preparing its personnel for the commissioning and operation of the Flamanville 3 reactor. Thus, apart from the 2,500-3,000 persons who are working on the construction site, nearly 350 person, employees of EDF, are working to acquire the skills necessary for the start up and operation of the nuclear reactor at the Flamanville 3 nuclear power plant (NPP). This NPP is distinct from the Flamanville NPP, which is responsible for operating reactors 1 and 2.

In November 2010, ASN made an initial inspection of the Flamanville 3 NPP by examining organisation and training of personnel, conditions for receiving qualification and the simulator and tools used for preparing operators in the control room. ASN stresses the importance of the overall procedure now implemented for creating a safety culture among teams.

ASN also examined the organisation implemented by the Flamanville 3 NPP to gradually take into account reactor systems as progress is made on the worksite. On this point, ASN has requested the Flamanville 3 NPP to monitor strict application of the order of 10 August 1984[5].


[1] Departmental Directorate for Regional and Maritime Affaires.

[2] Prefectorial order authorising EDF SA to carry out water and waste discharge sampling during the construction phase of an EPR-type nuclear power plant in Flamanville in accordance with articles L.214-1 et seq. of the Environmental Code.

[3] A construction joint is the area of contact between two layers of concrete placed at different times. Construction joint surfaces must be treated, generally by mechanical means, to provide a sufficient degree of adhesion between the two layers.

[4] EPR Technical Code for Civil Works (ETC-C): design and construction rules for civil works on the EPR.

[5] Order of 10 August 1984 relating to the quality of the design, construction and operation of basic nuclear installations.

Date of last update : 26/11/2021