ASN Report on the State of Nuclear Safety and Radiation Protection in France in 2017

Published on 13/04/2018 • 09:21 am

Information notice

A satisfactory year on the whole: the situation is less worrying, but several issues require particular attention

ASN considers that in 2017 the operating safety of the large nuclear facilities and radiation protection in the industrial and medical sectors were maintained at a satisfactory level on the whole. Nevertheless, for the EDF nuclear fleet, continued vigilance is required: the control of equipment conformity and the detection, notification and handling of deviations must be improved.

The general situation appears in other respects to be less worrying:

  • The anomaly relative to the carbon-rich segregate zones in steels has been widely dealt with, particular as regards the EPR reactor pressure vessel and the steam generators of the reactor fleet in service;
  • The review of all the manufacturing files of the Creusot Forge plant is progressing satisfactorily;
  • The industrial reorganisations and recapitalisations of EDF and Areva have been carried out.

The scale of the safety and radiation protection issues, however, is unprecedented. These issues will necessitate the maintaining of a high level of vigilance:

  • To better prevent and detect irregularities such as those found at the Creusot Forge plant, ASN in 2017 looked into ways to improve the oversight and monitoring system. The full plan of action will be finalised in the first half of 2018, but steps have already been taken in this direction.
  • The essential question of the extension of the service life of the oldest nuclear facilities is posed. ASN plans giving an overall opinion on the continued operation of the 900 MWe reactors beyond their fourth 10-yearly outage in 2020. In this context, ASN will make a statement on the safety improvements it deems necessary. The public will have the opportunity to participate in the development of this overall opinion. The continued operation of each of the reactors will then, after public inquiry, form the subject of an ASN authorisation; conformity of the reactors with their original baseline requirements will be examined on that occasion.
  • The nuclear facilities under construction (Flamanville EPR; Jules Horowitz reactor; Iter project at Cadarache) are experiencing significant delays and numerous difficulties due primarily to the loss of experience in design and construction. With regard to the EPR, ASN underlines that EDF still has a considerable amount of work ahead of it to substantiate the fitness of the nuclear pressure equipment for service. Moreover, ASN shall be particularly attentive to the performance of the pre-startup tests, which are of major importance in the verification of conformity of the facility with its baseline safety requirements. On 10th April ASN conducted an inspection of the welds of the main secondary systems of the Flamanville EPR reactor following the detection of defects by EDF, defects which were not seen during the first inspections performed during production.
  • The management of radioactive waste constitutes a major safety issue. A public debate on the National Plan for Radioactive Materials and Waste Management (PNGMDR) should be held at the end of 2018.
  • The continuation of the post-Fukushima work: despite having introduced numerous reinforcements on the facilities, major works still have to been carried out.
  • In the area of radiotherapy, ASN still observes shortcomings in certain departments, particularly in the management of technological and organisational changes. Vigilance must therefore be maintained, especially given that seven incidents were rated level 2 on the ASN-SFRO scale in 2017 (in external-beam radiotherapy, brachytherapy and interventional imaging). The overexposure of a pregnant woman during a computed tomography examination at the Le Mans hospital, recently notified to ASN, confirms the need for heightened vigilance.

ASN is currently contributing to the finalisation of the regulations on the security of radioactive sources. The first ASN inspections in this area are planned for the second half of 2018. This will be a first step in the field of security for ASN.

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ASN wishes to convey two messages concerning issues to address in the medium term:

  • The national electrical power system must have adequate margins to cope with a generic anomaly affecting the nuclear fleet.
  • The highest level waste (HLW and ILW-LL) must have a long-term management solution. The Cigéo project, for which the safety options constitute a significant step forward, is intended to meet this requirement.

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When the ASN report was presented to the OPECST, the exchanges with members of parliament more specifically concerned:

  • The rating of the nuclear power plants: some sites stand out positively, such as Fessenheim in the area of nuclear safety and protection of the environment, and Chinon in the area of radiation protection, as in 2016. Other sites however have substandard ratings, particularly Belleville-sur-Loire in the area of nuclear safety, Nogent-sur-Seine in radiation protection and Dampierre-en-Burly and Nogent-sur-Seine in environmental protection. The Belleville-sur-Loire NPP was placed under tightened surveillance in 2017.
  • The deviations detected in certain welds on the main steam transfer pipes of the Flamanville EPR: inspections conducted during in-plant production and on-site assembly showed that some welds do not have the required mechanical properties. Tightened requirements (for the mechanical properties in particular) had been adopted for these pipes in order to attain a high standard of production quality. However, these tightened requirements were not specified to the subcontractor responsible for these welding operations on site and in the factory.
  • Flamanville EPR reactor: the welding defects on the main secondary systems which were not detected during production: inspections were undertaken in early March 2018 as part of the "complete initial inspection" prior to commissioning provided for in the regulations governing nuclear pressure equipment. They revealed weld defects which had not been detected during the end-of-production inspections performed by a Framatome subcontractor. This finding led EDF to rapidly conduct inspections on all the welds in these systems. On 10th April 2018, ASN carried out an on-site inspection to examine the conditions of performance of this inspection campaign and to seek the causes of the failure to detect the defects during the end-of-production inspections. ASN will make a position statement on the corrective actions proposed by EDF in the light more specifically of the inspection results which will be communicated to it next month.

Compliance with these tightened requirements contributes to the quality of manufacture, which constitutes a prerequisite for considering that rupture of these pipes is extremely improbable and hence exempts the need to study the consequences of such rupture in the safety case of the facility.

ASN has asked EDF for a complete file on the history of the detection of this anomaly and the possibilities of dealing with it.

Contact: Evangelia Petit, Head of the Press Department, tel: (+33) 1 46 16 41 42 evangelia.petit@asn.fr

 

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Date of last update : 13/04/2018