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of exposed workers( classified in category A or B, exposed to radon at more than 6 mSv / year, or identified as responders in a radiological emergency situation) must be recorded in SISERI. Some establishments belonging to the field of medical, dental and veterinary activities, where many workers are not classified( more than a third of the workforce), have begun to take this article of the Labor Code into account and no longer register these workers in the new SISERI portal.
With around 60 % of all monitored workers, the medical, dental, and veterinary fields are the most important field, followed by the nuclear field( around 25 %). About 6 % of monitored workers are exposed to natural radiation.
Besides workers without assigned activity, the“ Others” category includes activities of inspection and control organizations, activities of transport of radioactive material whose used is not specified, foreign activities, management of the crisis situations( fire brigade, civil protection) and the external dosimetry laboratories. The number of monitored workers in the“ Others” category has fallen since 2015, which can be explained by the fact that the activities of workers are increasingly better informed within SISERI. The“ Others” category represented 13 % and 5 % respectively of the total number of monitored workers in 2015 and 2023( Fig. 3f).
Exposed workers are the monitored workers having received a dose above the dosimeter recording threshold. The proportion of the exposed workers has been relatively stable since 2015( between 23 % and 25 %). The proportion of exposed workers in 2023 is the most important in the natural radioactivity exposure field( around 97 %), followed by the nuclear field( 39 %) and the non-nuclear industry field( around 16 %)( Figs. 3e, 3b and 3c). It is relatively low in the research activities and in the medical and veterinary activities( resp. 8 % and 13 %)( Figs. 3a and 3d). In the research activity field, the proportion of exposed workers is relatively stable, except in 2023, when it decreases slightly( Fig. 3d).
3.2 Average annual dose
The average annual dose is calculated from data of exposed workers( workers having received a dose above the dosimeter recording threshold), taking into account the various components of ionizing radiation( gamma, beta, neutrons).
Between 2015 and 2020, the average dose increases, except in 2020( Fig. 2). Forthesame reason indicated about thedecrease of the monitored workers number in 2020, the average dose also decreases in 2020. The average dose increases again between 2021 and 2023. It is, however, less than the years before COVID-19. The increase of average dose observed since 2021 is partly due to a resurgence of activities in all fields, but it is mainly due by the increase in maintenance works in nuclear field, such as ten-yearly inspections of reactors, or activities in relation with the treatment of the stress corrosion phenomenon on reactors, etc.( in 2021 and 2023) and the increase in air traffic in the natural radioactivity exposure field( in 2022).
In the medical, dental and veterinary activities, the average dose is globally stable through the 2015 – 2022 period, except in 2020 where it decreases( Fig. 3a). The decrease in 2020 is due to COVID-19, causing the activity decrease in medical and veterinary fields. The average dose in 2023 in this field is 0.29 mSv( as in 2022).
After an increase in 2018 and 2019, the average dose in the nuclear field decreases in 2020 and increases in 2021( Fig. 3b). It is followed by a decrease in 2022 and an increase in 2023. In 2023, the average dose in the nuclear field is 1.35 mSv, an increase of 7 % compared to 2022. As written before, the increase is due to the increase in maintenance works in relation to the ten-yearly inspections on reactors, the treatment of the stress corrosion phenomenon on reactors, etc.
In the non-nuclear industry field, the average dose fluctuates through the 2015 – 2023 period, with a downward trend until 2022 and a significant increase in 2023( Fig. 3c). The average dose recorded in 2023 is 1.42 mSv( compared with 0.97 mSv in 2022). The increase in the average dose in 2023 in this field is partly due to a case where the regulatory limit for effective dose was exceeded, but this has still not been confirmed by occupational medicine. The average dose in the non-nuclear industry would be 1.21 mSv if this case of exceeding the effective dose regulatory limit is not considered.
Through the 2015 – 2023 period, the average dose in the research activities increases since 2017( except in 2020 and 2023 where it decreases( Fig. 3d). Unlike other fields of activity, the average dose in 2023 in the research activities is down 21 % compared to 2022.
The average dose in the natural radioactivity exposure field increases between 2015 and 2019. It fluctuates between 2020 and 2023( Fig. 3e). The increase of average dose in this field in 2021 and 2022 is mainly due to a resurgence of activities in air traffic after the period of COVID-19. In 2023, the average dose recorded in this field is 1.17 mSv( 1.41 mSv in 2022). The decrease of the average dose in 2023 compared to 2022 is perhaps due to an improvement in the alternation of the aircrews between the long-haul / medium-haul flights and the short-haul flights, the latter leading to a lower exposure. Most monitored workers in the natural radioactivity exposure field have received more than 0.1 mSv( threshold applied for the flight aircrews to be homogeneous with the workers using the dosimeters), except in 2021.
In 2023, distribution of monitored workers across activities fields is stable compared to the previous years( Fig. 4). Among the 360,743 workers monitored in 2023, medical, dental and veterinary activities remain the majority( 58 % of the workforce). The nuclear industry still represents around a quarter of the workforce. The natural sector represents around 6 % of the workforce. The non-nuclear industry and research represent 4 % and 3 % of the total monitored workforce, respectively. In terms of collective dose, the two main contributors are the nuclear domain with 54 % of the total collective dose and the natural domain with 31 % of the total collective dose. Medical, dental and veterinary activities contribute approximately to 9.5 % of the total collective dose. As regards the average annual individual doses on the exposed workforce, differences between the fields of activity remain since, as in previous years, the nuclear sector is among the fields with one of the highest values.
3.3 Cases of annual effective dose exceeding the regulatory limit of 20 mSv / year( 2015 – 2023)
Figure 5 presents the number of workers whose the annual effective dose exceeds the regulatory limit of 20 mSv per year by activities field, through the 2015 – 2023 period.