Full set of answers to questions on the review of manufacturing files by AREVA NP

  • 1. How were the deficiencies detected in the components manufactured by the Le Creusot site?

    AREVA NP launched a quality audit in April 2015 after errors were detected in the use of the tensile testing machine at the Le Creusot Laboratory. An initial analysis of these practices was conducted from April to September 2015 by AREVA NP and by an independent firm, Lloyd’s Register Apave. It led AREVA NP, at the end of 2015, to reexamine the manufacturing tracking records. This review revealed that certain information did not appear in the end-of-production reports and had not been brought to the attention of customers. For this reason, these records had been marked with one or two strokes, which is why they are referred to as the "marked records" ("dossiers barrés"). AREVA NP initially examined these dossiers in detail and then decided to extend the review to all files concerning nuclear components manufactured at Le Creusot.

  • 2. What is a manufacturing file? What is the difference with the end of manufacturing report?

    The manufacturing file tracks the chronology of the various steps in the manufacture of a part and it covers all the technical requirements to be met. The file includes all the reports relating to manufacturing operations, chemistry, heat treatments, mechanical properties, welds, etc. that attest to the conformity of the part. The manufacturing file for a forged or molded part (a shell for example) counts on average 400 pages.

    The end-of-manufacturing report (EMR) on the other hand contains all the documents attesting that the contractual requirements have been met according to the provisions agreed with the customer. As such, it does not include the entire manufacturing file. The EMR is transmitted to the customer.

  • 3. How is the information contained in the file remitted to the customer checked?

    A systematic review of the documentation is carried out both upstream and downstream of manufacturing operations. Upstream, meticulous analysis of manufacturing, inspection and procurement specifications is conducted with regard to both compliance with the current manufacturing code (the RCC-M Code for instance) and regulations. Following manufacture of the components, it is verified that all the documents required to demonstrate compliance are included in the end-of-manufacturing report (report, certificate, tracking records completed).

    This review establishes that the equipment complies with current regulations and contractual requirements. Workshop inspections are also carried out by the customer and notified bodies.

    Without this body of substantiating evidence, compiled as the manufacturing process proceeds, a piece of equipment cannot be put into service. It serves to attest to the conformity of the equipment. Under the French regulatory framework for nuclear pressure equipment effective since 2006, this certificate is a regulatory act incumbent on the notified body mandated by the ASN.

  • 4. What documents are sent to the safety authorities?

    The regulatory authorities and notified bodies authorized by them to carry out inspections have access to all the documents making up the manufacturing file.

  • 5. What is the nature of the deficiencies detected at Le Creusot and what are their impacts on the safety of the nuclear fleet?

    The deficiencies brought to light are either documentary deficiencies (missing documents, inaccurate transcriptions or missing values), or non-compliant practices during testing or manufacturing. These practices are unacceptable from the point of view of quality assurance. The analysis of these irregularities, supplemented where necessary by additional tests on representative parts or on remaining material, has demonstrated the integrity of the equipment concerned, and the ASN has confirmed the absence of any safety impact for the deficiencies examined so far.

    With the framework of the on-going audit at the Le Creusot site, only a single component of one of the steam generators in operation in the EDF fleet (Fessenheim 2) is subject to a justification and complementary test program using sacrificial parts with similar characteristics. Another shell installed on one of the steam generators belonging to the Flamanville 3 EPR is subject to a justification and complementary test program using a sacrificial part. A shell installed on a steam generator which was to be installed at Gravelines 5 will be replaced. On some parts, additional tests will be carried out to provide formal justifications.

  • 6. Can you tell us what is meant by a deficiency? A deviation report? A non conformance?

    In the audit of manufacturing files, any missing document, any incorrect transcription, any missing value or any suspicion of unacceptable practice is identified as a deviation. Their detection systematically leads to the creation of a report.

    An analysis of the report is conducted to qualify the deficiency or not. The reports are therefore classified in one of three ways:

    No deficiency

    Cases where the processing has not brought to light any deficiency with respect to internal instructions, documents pertaining to the order or to maufacturing documents, to the code or to regulations. In the case of these reports found without deficiency, all the substantiating elements required for the technical analysis are available in the file and no additional elements are necessary.

    Internal non-conformance report

    Cases where the deficiency is with respect to an internal requirement.

    Deviation report

    Case where a part is non-conforming with respect to contractual or regulatory requirements. At this stage of the audit, all deviation reports have led to conclude that the part in question can nevertheless be used as is or be restored to an acceptable condition by provisions to be established. Usage as is or provisions to be implemented require the opinion of the customer to be sought beforehand. A distinction is made between technical deviation reports (deviations from customer specifications or procurement specifications), deviation reports concerning con-conformance with respect the applicable Code, and deviation reports concerning con-conformance to current regulations.

  • 7. In what respects are the practices identified unacceptable?

    Any documentary or methodological deficiency that is not identified as such or not referred to when drawing up the documentation constitutes an unacceptable practice from the point of view of quality assurance. Since 2015, AREVA NP has deployed actions aimed at strengthening the quality and safety culture of its employees at the Creusot Forge plant. The plan currently being deployed at the le Creusot site also includes actions to strengthen control and oversight.

  • 8. In July 2016, ASN suspended the certificate corresponding to one part of a reactor at Fessenheim. Is this reactor safe?

    In the course of the quality audit launched at the Le Creusot plant, in May 2016 AREVA NP detected a deviation in the manufacture of the lower shell of a steam generator installed on the No. 2 reactor at the Fessenheim power plant. At that point AREVA NP opened a deviation report and informed EDF and the nuclear safety authority. On July 18, 2016, ASN decided as a precautionary measure to suspend the test certificate for the secondary part of this component. Initial technical analyses conducted in 2016 by AREVA NP experts concluded that the deviation detected did not compromise operational safety. However, to be absolutely sure of the robustness of the shell component, similar parts were cast and forged at Le Creusot in order to substantiate its characteristics and chemical properties. AREVA NP is continuing its analysis in order to specify appropriate measures to secure the lifting of this suspension. The analysis of this file by ASN should take place by the autumn of 2017.

  • 9. How are you going about the examination of the manufacturing files at the Le Creusot site?

    To carry out this project, we have set up a dedicated team. Following a ramp up phase in early 2017, the team now numbers 170 staff. This team is contributing to the page-by-page inspection of the records, bringing its technical expertise to bear on the deviations found, and processing the deficiencies in coordination with the customers and authorities concerned. More than 2.4 million pages will be digitized and analyzed running into 2018. Each page is analyzed in detail in order to identify deficiencies both in the transcription and in the execution of operations. A file may contain several discrepancies. The inspection of one file represents of the order of two to three days of work.

     

    Revue Qualité - Rappel du processus FR

  • 10. How much progress has been made on the 6,000 manufacturing files from Le Creusot? 

    In September 2016, AREVA NP opted to extend the quality review in progress at its Le Creusot site to encompass all of the records relating to nuclear components manufactured at the site. The review was also extended to the group's manufacturing sites at Saint-Marcel and Jeumont. To date, the audit is progressing according to the schedule established with the customers concerned and the competent regulators, world-wide.

    In order to analyze the 6,000 production files at the Creusot site, a dedicated team has been ramping up since autumn 2016. By May 2017, it counted over 170 members. This team is contributing to the page-by-page inspection of the records, bringing its technical expertise to bear in classifying and characterizing the deficiencies found, processing them (justification, issuance of the deficiency sheet) and keeping the customers concerned informed. More than 2.4 million pages are being digitized and analyzed by this team. Priority is being given to the parts equipping reactors in service, as well as the EPR reactors under construction.

    The deficiencies identified undergo a characterization and are then dealt with in coordination with the customers and safety authorities concerned. These deficiencies correspond to either documentary anomalies (transcribing errors, missing records, etc.) or practices that do not conform to the plant's quality assurance system, to the technical specifications of the customers or to regulations. In a file containing an average of around 400 pages, several deficiencies may be identified.

  • 11. On January 10, the U.S. Nuclear Regulatory Commission (NRC) published a list of reactors with components forged at Le Creusot. Where is the audit up to with regard to components supplied to customers abroad?

    The NRC has published a list of 17 reactors in the USA for which parts were forged at Le Creusot. The US safety authority has indicated in its various communications that the evaluations conducted up until this stage have confirmed there is no reason to call the safety of US reactors into question. In general, since the launch of the audit in 2015, AREVA NP has always been in contact with the customers and regulators concerned, keeping them informed of the deficiencies identified and their handling.

  • 12. How do you explain that fact that these deviations were not detected during manufacture and, in particular, through checking and inspection procedures?

    Based on the information gathered during the audits carried out at its manufacturing sites, AREVA NP is conducting in depth analysis of the causes of the occurrence and non-detection of irregularities in past production. This work is feeding into the improvement plan being deployed at the Le Creusot site, notably through a component on strengthening the safety and quality culture.

    Moreover, more than 2,700 inspections have been carried out over the last 10 years. This confirms the need for a change in our oversight and inspection practices. This is one of the key areas of the improvement plan at the Le Creusot site.

  • 13. How is the quality and safety of manufacturing in progress being safeguarded?

    As soon as the first anomalies were discovered at the Le Creusot site, AREVA NP reinforced the control and the traceability of the manufacturing in progress. AREVA NP has implemented a process which involves the double-checking of documentation and strictly limits the copying of test reports, which is a source of transcription errors. We have also instigated third party oversight.

    The improvement plan is currently being deployed and we are planning to invest in new production equipment. Once this work is complete, we will have at Le Creusot a production facility and a quality management system which meet the most stringent worldwide standards.

    The production, starting March 2017, of test pieces - including an EPR type primary leg and a 1300 MWe type SG nozzle shell - will serve to substantiate the operational, organizational and technical effect of the actions decided under the plan.

  • 14. What is a tensile test?

    A tensile test consists in stretching a representative piece of metal, commonly referred to as a sample, measuring approximately 12 cm, on a test bench, until it fractures. A sensor (extensometer) is fastened to the sample to measure changes in length as a function of the force exerted on the piece at a constant speed. The data recorded in this way make it possible to determine the yield point of the material and its tensile strength.

    The test is carried out at different temperatures according to the applicable codes and standards and the customer's specific requirements: at ambient temperature or under temperatures (ranging from 150° C to 350° C).

    Four values are recorded:

    • Yield point: maximum tensile force beyond which the sample or test piece cannot regain its initial shape when the traction ceases
    • Tensile strength: maximum stress sustained by the sample or test piece before fracture
    • Elongation: measurement of the stretch of the sample or test piece at breaking point
    • Reduction in area: measures the reduction in cross section of the sample or test piece after fracture, relative to the initial section.
  • 15. What was the deficiency in the tensile tests at Le Creusot identified during the 2015-2016 audits?

    The analysis of the records from the tensile testing machine used at Le Creusot revealed a problem with how the tests at the Le Creusot laboratory were run. In particular, digitized data showed that the deformation rates applied to the samples or test pieces were non-compliant in certain phases of the tests.