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From the source to the dosimetric impact assessment

The different monitoring programs for workers

​Different monitoring programs allow verifying that the required protection level for exposed personnel is well respected.

Published on 17 March 2015
This is why they are integrated into the radiological safety program, which begins with the identification of normal working conditions.
Collective monitoring, which includes the monitoring of workplaces, provides the estimate of doses for a group of workers from the same workplace, i.e. those that are exposed to the same risks.
Individual monitoring provides the data necessary to assess the exposure of a single worker, by wearing a passive or operational dosimeter and measuring selected activities or excreta.
Routine monitoring (systematic) is set up during continuous operations under normal conditions. It is based on the assumption that work conditions and the associated risk remain constant.
Special monitoring is required to quantify significant exposures following suspected abnormal events. The date and circumstances of the event are known.
A control monitoring may be required to verify the assumptions made relating to specific sites. It is limited by time.

These different monitoring programs are based on:

  • technical controls: inspections of facilities, ventilation, surface and volume contamination,
  • dosimetric monitoring: passive or operational dosimeters, radiotoxicological doses on bioassays or in vivo exams,
  • medical monitoring by searching for the occurrence of undesirable events.

Tests for non-contamination of the body and clothing are mandatory when leaving the controlled zone: SIRIUS (inspection of hands, feet and clothing).

In case of contamination, an audible and visible alarm alerts the agent, who immediately activates the adjacent ‘contamination call button’ (BAC) and warns the SPR agent.

Inspection when leaving the zone,
Photo credit: C.Dupont/CEA
External exposures are monitored by wearing dosimeters that are specific to the manipulated compound. In case of an event, a dosimetric reconstruction must be performed using all available items (detectors, metal or jewelry, blood, hair, teeth, cell phones, etc.) depending on the circumstances.
Internal exposures are monitored by measuring the presence of radioactive substances in the body (in vivo) or by measuring their elimination from the body (in vitro), through routine or special monitoring after an event, and under the responsibility of the occupational physician.
The services and laboratories that quantify the analyses, dosages and inspections of these monitoring operations are certified and licensed.