European stress tests

ASN, in charge of the regulation of the French nuclear installations, requested operators on 5 May 2011 to undertake complementary safety assessments (CSA) of their installations following the accident that occurred in Japan on 11 March 2011. The process, which consists of in-depth operating experience feedback from this event, will be spread over several years, as was the case after the Three Mile Island and Tchernobyl accidents.

The assessment approach responds to both the Prime Minister's and the European Council's requests to carry out a safety audit of the country's nuclear installations; the complementary safety assessments are based on the provisions of the specifications approved by ENSREG last May. In France, these in-depth safety examinations are carried out in all installations, including research and fuel processing installations; sub-contracting has been taken into account in CSAs of French installations.

In June ASN received and examined, with its technical support organisation, IRSN, memoranda presenting the methodology selected by each operator for conducting the CSAs. 79 installations were considered high priority (including 58 nuclear reactors operated by EDF): on 15 September 2011 their operators submitted reports on the safety status of these installations in relation to the CSAs. Reports relating to other installations will be submitted to ASN no later than 15 September 2012.

When ASN, its technical support organisation IRSN and expert groups have finished analysing these reports, ASN will present its conclusions at the end of 2011. A final report will be sent to the European Commission by the French authorities no later than 31 December 2011.

Stress Test News

This section contains the latest information notices and press releases concerning the stress tests.

Published on 05/10/2012 at 11:32

European Stress Tests

ASN notes the communication of the European Commission on Thursday October 4, 2012 on “stress tests” on nuclear power plants in Europe conducted after the Fukushima disaster claims to be based on the results published in the stress tests final report adopted on April 26, 2012. ASN regrets the working methodology used by the Commission for drawing its conclusions. These conclusions ignore some important recommendations of the stress-tests final report.

Published on 28/06/2012 at 09:00

ASN's 2011 report : "there is a before and an after Fukushima"

ASN imposes large-scale safety reinforcement work on the licensees following the CSAs

Today, 28th June 2012, ASN presented its 2011 Report on the state of nuclear safety and radiation protection in France and also reviewed the follow-up to the Complementary Safety Assessments (CSAs) conducted on the nuclear facilities in the wake of the Fukushima-Daiichi accident.

Published on 04/05/2012 at 10:20

Report on the results of stress tests

The European Nuclear Safety Regulators Group (ENSREG) and the European Commission have adopted, on April 26 2012, the report on the results of the stress tests on European nuclear power plants.
This report responds to the request from the European Council on 25 march 2011 asking for the launch of stress tests on the European nuclear power plants to take account of the first lessons learned from the Fukushima accident.
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Milestones for complementary safety assessments

The 12 resolutions taken by the ASN Commission on 5 May 2011 require the various operators of nuclear installations to prepare a report in response to detailed specifications, according to the following time-line:

  • 1 June 2011: submit a memorandum presenting the selected methodology for conducting the assessment, the organisation implemented to meet the deadlines set and the detailed structure planned for the report;
  • 15 September 2011: for priority installations including nuclear power plants, the operators send a report presenting the conclusions of the assessment. This report will propose additional studies and an appropriate time-line for them;
  • 15 January 2012: submit memoranda with the methodology for lower priority installations;
  • 15 September 2012: send reports for lower priority installations.


In order to analyse the reports for priority installations, ASN referred to IRSN and two permanent expert groups (GPE) for reactors and plants. These experts worked to the following time-line:

  • 6 July 2011: meeting and opinion of GPE on methodology memoranda;
  • 19 July 2011: ASN position statement on methodology memoranda;
  • beginning of November 2011: report from IRSN on complementary safety assessments of priority installations;
  • 8-10 November 2011: GPE meeting to analyse operators' reports.

ASN will issue its report on the complementary safety assessments (CSA) at the end of 2011.

Complementary safety evaluation of French nuclear installations in the light of the accident of Fukushima

ASN believes that it is essential to learn from the accident which occurred at Fukushima-Daiichi nuclear power plant, as it has been undertaken after the Three Mile Island and the Chernobyl accidents.

The in-depth experience feedback will involve a long process stretching over several years. Some lessons, however, can already be learned.

On 5 May 2011, the ASN Commission adopted 12 decisions requiring to licensees of French nuclear installations to conduct a complementary safety evaluation of their installations in the light of the accident which occurred in Fukushima.

The French High Committee for Transparency and Information on Nuclear Security (HCTISN) has contributed to the decisions’ drafting; during its extraordinary meeting which HCTISN held on 3 May 2011, this committee approved the specifications submitted by ASN.

This complementary safety evaluation will consist in a targeted reassessment of the safety margins of nuclear installations in the light of the events which occurred in Fukushima: extreme natural conditions challenging the installation safety functions and leading to a severe accident.

Three main aspects need to be reported in this assessment :

  • Provisions taken in the installation design basis and installation compliance with its current licensing requirements;
  • Robustness of the installation beyond its design basis; the licensee shall identify scenarios leading to a sudden degradation of accidental sequences and will describe preventive measures aimed at avoiding them;
  • Any potential modification likely to improve the installation safety level .

These complementary safety evaluations will concern all French nuclear installations but will focus, first of all, on nuclear power plants.

Licensees must submit their reports to ASN by 15 September 2011.

ASN and its technical support organization, IRSN (Institute of Radiation Protection and Nuclear Safety) will review them by 15 November 2011.

This approach supplements the safety regulation currently in force. ASN is devoting significant resources to this effort.

  • Resolution no. 2011-DC-0213 by the French Nuclear Safety Authority dated May 5, 2011, instructing EDF to carry out a complementary safety assessment on some of its basic nuclear installations in the light of the accident which has occurred at the Fukushima Daiichi nuclear power plant (including specifications for the complementary safety assessment of nuclear installations in the light of the Fukushima accident)
  • Specifications for the complementary safety assessment of nuclear installations in the light of the Fukushima accident: Risks of flooding, earthquake, loss of power supply and loss of cooling, in addition to operational management of accident situations
  • Annex 2 to Resolution no. 2011-DC-2013 by the French Nuclear Safety Authority dated 05/05/2011 instructing EDF to carry out a complementary safety assessment on some of its basic nuclear installations in the light of the accident which has occurred at the Fukushima Daiichi nuclear power installation

ASN resolutions

By the resolutions taken on 5 May 2011, the French Nuclear Safety Authority (Autorité de sûreté nucléaire – ASN) has required all operators of relevant basic nuclear installations, including AREVA, the French Alternative Energies and Atomic Energy Commission (Commissariat à l’énergie atomique et aux énergies alternatives – CEA), the French national power utility (Électricité de France – EDF) and the Laue-Langevin Institute (ILL[1]) to submit by 1 June 2011 at the latest, a memorandum describing the methodology they adopted in order to conduct the complementary safety assessment (évaluation complémentaire de la sûreté – ECS) for some of their installations with respect to the nuclear accident that occurred at the Fukushima-Daiichi Nuclear Power Plant (NPP) in Japan, on 11 March 2011.

Published on 01/03/2013

ASN STATUTORY RESOLUTIONS

ASN resolution 2012-DC-0305 of 26 June 2012

ASN resolution 2012-DC-0305 of 26 June 2012 instructing the AREVA NC company to comply with additional requirements applicable to basic nuclear installation (BNI) called TU5, located on the Tricastin site (Drôme département) in the light of the conclusions of the Complementary Safety Assessment (CSA)

Published on 01/03/2013

ASN STATUTORY RESOLUTIONS

ASN resolution 2012-DC-0304 of 26 June 2012

ASN resolution 2012-DC-0304 of 26 June 2012 instructing the SOCATRI company to comply with additional requirements applicable to basic nuclear installation (BNI) 138 called SOCATRI, located on the Tricastin site (Drôme département) in the light of the conclusions of the Complementary Safety Assessment (CSA)

Published on 01/03/2013

ASN REGULATORY RESOLUTIONS

ASN resolution 2012-DC-0303 of 26 June 2012

ASN resolution 2012-DC-0303 of 26 June 2012 instructing the MELOX SA company to comply with additional requirements applicable to basic nuclear installation (BNI) 151, called MELOX, located on the Marcoule site (Gard département) in the light of the conclusions of the Complementary Safety Assessment (CSA)
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ASN report

ASN published its report on the complementary safety assessments (CSA) carried out further to the Fukushima accident in Japan.
The ASN President, André-Claude Lacoste, delivered it personally to the Prime Minister on 3rd January 2012.

Following the complementary safety assessments of the priority nuclear facilities, ASN considers that the facilities examined offer a sufficient level of safety for it not to request the immediate shutdown of any of them. At the same time, ASN considers that for the continuation of their operation, an increase in the robustness of the facilities to extreme situations, beyond their existing safety margins, is necessary, as rapidly as possible.

Targeted inspections

As well as the complementary safety assessments, in 2011 ASN undertook a campaign of targeted inspections on themes linked to the Fukushima accident. These inspections were conducted on all priority nuclear installations and were intended to check the compliance of equipment and the operator's organisation, on site, compared to the existing safety reference framework.
The following themes were covered during these inspections:

  • protection against external hazards, particularly earthquake resistance and protection against flooding,
  • loss of electrical power supplies,
  • loss of cooling sources,
  • operational management of emergency situations.

38 inspections were programmed and carried out by teams including several ASN inspectors and experts from IRSN. This inspection campaign represents 110 days of on-site inspections.
The inspections were programmed between June and October 2011. For a given site, they took place in the form of in-depth inspections over several days (continuous or discontinuous), enabling all the themes listed above to be covered. They were based on a common reference framework for nuclear power plants, on one hand, and other nuclear installations, on the other hand, and favoured site visits over documentary audits.
The inspections resulted in follow-up letters sent to the operators and put online at www.asn.fr
71% of targeted inspections had been carried out by 15 September 2011. ASN will analyse the conclusions of all these inspections before the end of 2011. ASN's conclusions will be included in the report on the complementary safety assessments submitted to the Government. If it considers it necessary, ASN may decide to impose additional requirements to improve the safety of installations.

European stress tests

The European 'stress tests' exercise arose out of European Council conclusions on 24 and 25 March that, two weeks after the Fukushima accident was triggered, wanted to submit European nuclear power plants to a complementary safety assessment.

In accordance with the mandate given by the European Council, the final agreement dated 25 May 2011 between the Safety Authorities and the Commission on the specifications for 'stress tests' of these power plants sets the major steps of the process:

  • 1 June 2011 at the latest: formal launch of stress tests for European nuclear power reactors in European countries;
  • 15 September 2011: each Member State sends ENSREG and the Commission an interim 'national report';
  • 31 December 2011: each Member State sends its final national report.

Besides these time-line items, the ENSREG (European Nuclear Safety Regulators' Group) specifications also state that the final national reports will be subject to peer review, from January 2012.

It is added that the European Commission will send an 'interim report' for the European Council meeting on 9 December 2011, and a final report for the European Council meeting in June 2012.