ASN Report 2018

(the collective dose is the sum of the individual doses received by a given group of persons) and the number of times the annual limit of 20 mSv was exceeded. They clearly show a significant disparity in the breakdown of doses depending on the sector. For example, the medical and veterinary activities sector, which comprises a significant share of the population monitored (close to 58%), only accounts for about 18% of the collective dose; on the other hand, the nuclear industry however, which represents about 20% of the headcount, accounts for more than 70% of the collective dose. The industrial sector, which represents 4% of the headcount, accounts for 5% of the collective dose. Table 3 shows that the total number of workers monitored by passive external dosimetry has increased by 1% since 2015. In 2017, the collective dose reached 53.5 man-Sv, a value that is about 20% lower than in 2016. This reduction is linked essentially to a drop in activity in the nuclear sector. The volume of maintenance activities at EDF in particular is lower than it was in 2016. The number of monitored workers whose annual effective dose exceeded 20 mSv has been stable since 2015 (1 to 2 exceedances per year); two cases exceeding the effective annual dose were observed in 2017 (an effective dose of 40.7 mSv for a worker in the non-destructive testing sector and an effective dose of 43.7 mSv for a medical worker) (see Diagram 2). With regard to the dosimetry of the extremities (fingers and wrist), 27,949 workers were monitored in 2017 (i.e. 8% of the total number of persons monitored). Out of all the persons monitored, there were four cases where the 500 mSv regulatory equivalent dose limit at the extremities was exceeded, all in the interventional radiology sector (the exceedances are situated between 510 mSv and 1,270 mSv). For the second year running, data relative to monitoring of the lens of the eye are available. Two thousand five hundred and five people were subject to monitoring of lens of the eye exposure. The maximum dose recorded is 44.1 mSv and concerns the area of medical applications. This value should be compared with the new regulatory dose limit for the lens of the eye: cumulative value of 100 mSv over five years, without exceeding 50 mSv in a given year (20 mSv/year as from 2023). The results of dosimetric monitoring of worker external exposure in 2017 published by IRSN in June 2018 show on the whole that the prevention system introduced in facilities where sources of ionising radiation are used is effective, because for 96% of the population monitored, the annual dose remained lower than 1 mSv (effective annual dose limit for the public as a result of nuclear activities). Exceeding the regulatory limit values remains exceptional. Sources and routes of exposure to ionising radiation External irradiation Internal contamination by inhalation of radioactive substances Skin contamination External irradiation Internal contamination through ingestion of contaminated foodstuffs Skin contamination and involuntary ingestion 98  ASN report on the state of nuclear safety and radiation protection in France in 2018 01 – NUCLEAR ACTIVITIES: IONISING RADIATION AND HEALTH AND ENVIRONMENTAL RISKS