A number of improvements were observed in 2022 in the field of subcontracted activities quality control, notably through the use of a new tool used to monitor the contractors. However, there are still difficulties regarding the quality of the monitoring provided (inappropriate monitoring plans, monitoring overly focused on quality assurance and safety rules, to the detriment of actual technical operations, contractors lacking certain required skills, etc.). ASN’s inspections also show a very positive move within the NPPs to improve the skills of the contractors and tangible measures such as the increase in the provision of spaces for preparation work on a mock-up. Management of operational documentation As in 2021, the significant event reports regularly point the finger at insufficient documentation quality. This is an underlying problem which has been a recurring one for a number of years. The difficulties identified are of various types (documentation not concise enough, not explicit, incomplete, or even non-existent). This has consequences for a wide range of activities, including control activities (periodic tests, lock-outs and administrative closures, line connections) and maintenance work (technical inspections, maintenance work on equipment, requalifications, local control actions). These documentation deviations remain to a large extent related to organisational malfunctions in the documentation creation and update process and they potentially compromise the documentary support line of defence. The Operating Experience Feedback process The quality and availability of the human resources assigned to the in-depth analyses of significant events are satisfactory on all the sites. The involvement of HOF skills in the analysis phase is tending to improve on most sites, which is a very positive point. ASN however finds that EDF often limits its analysis to the situations and systems involved in the events and does not learn the lessons adequately with respect to similar situations or systems. Moreover, reports presenting criteria for measuring the effectiveness and the conditions for closure of the proposed corrective measures are still rare. 2.7 Personnel radiation protection 2.7.1 Exposure of personnel to ionising radiation Exposure to ionising radiation in a nuclear power reactor comes primarily from the activation of corrosion products in the primary system and fission products in the fuel. All types of radiation are present (neutrons, α, ß and γ), with a risk of internal and external exposure. In practice, more than 90% of the doses received come from external exposure to ß and γ radiation. Exposure is primarily linked to maintenance operations during reactor outages. Despite a year 2022 marked by the work concerning the stress corrosion problem, the average collective dosimetry on all the reactors (see Graph 5), and the average dose received by the workers for one hour of work in the limited access area (see Graph 6) was down in 2022 by comparison with 2021. Graph 7 shows the breakdown of the workers according to whole body external dosimetry. In 2022, the share of workers for whom the dosimetry was below one millisievert (mSv) rose slightly (77% in 2021 as against 75% in 2021). The annual regulation limit for whole body external dosimetry (20 mSv) was exceeded on no occasion in 2022. Graph 8 shows the trend in whole body average individual dosimetry according to the categories of disciplines of the workers in the NPPs. As in previous years, the most exposed workers are the personnel responsible for heat insulation, for whom the average individual dose rose in 2022. The other categories of disciplines most exposed also remain unchanged: welders, personnel in charge of inspection, mechanical and ancillary activities. For these latter discipline categories, the average individual dose however fell in 2022. Significant contamination events EDF reported six significant contamination events concerning workers in the NPPs in 2022. For the workers concerned, these events led to exposure to a level higher than one quarter of the annual regulation limit per square centimetre of skin, and were rated level 1 on the INES scale. Unlike in 2021, no event led to exposure higher than the regulation limit for the skin. The workers concerned by these events were given care and the radioactive particles responsible for their contamination were removed, in accordance with the procedure applied by EDF. 2.7.2 Assessment of personnel radiation protection ASN monitors compliance with the regulations relative to the protection of workers liable to be exposed to ionising radiation in NPPs. In this respect, ASN is attentive to all the workers on the sites, both EDF personnel and those of contractors. This monitoring is performed during inspections once or twice per year and per NPP, specifically on the topic of radiation protection, or during reactor outages, as well as following significant events, or more occasionally in the EDF head office departments and engineering centres. It is also carried out during examination of the worker radiation protection files (significant event reports, design, maintenance or modification files, documents implementing the regulations and produced by EDF, etc.). During inspections carried out in 2022, ASN found progress in the prevention of dissemination of radioactive contamination outside the installations. ASN also examined the procedures for treatment of contaminated personnel, in order to check that the time taken to initiate treatment enables the exposure time of the workers to be reduced. On several inspected sites, this subject was considered to be satisfactory. Nonetheless, during inspections on worksites in limited access areas, the ASN inspectors continue to observe faults in the implementation of containment resources. In addition, the inspection findings and several significant events reported show difficulties with managing the processes involved in industrial radiography work and in access to the operations area. ASN will be remaining vigilant on these issues during the course of 2023. 2.7.3 The organisation of radiation protection in the Nuclear Power Plants The Order of 28 June 2021 relative to the radiation protection expertise centres requires that as of 2 January 2022, the NPP “Radiation Protection Adviser” duties of the licensees of NPPs and of the employer are no longer performed by the “Radiation Protection Expert-Officer” (RPE-O) but by the radiation protection expertise centres mentioned by the Environment Code and the Labour Code. These centres comprise persons with the skills and qualifications needed to provide advice and support on subjects concerning protection of the population and the environment from ionising radiation, as well as worker radiation protection. The Order also states that these centres require ASN approval by 2 January 2023. Pending this approval, the EDF NPPs had set up provisional expertise centres during the course of 2022. 306 ASN Report on the state of nuclear safety and radiation protection in France in 2022 • 10 • The EDF Nuclear Power Plants 10
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