INES-event
INES 1

Unplanned exposure of workers

Unit 4 of NPP Bohunice was shut down for refuelling and yearly overhaul, the fuel and all internals were out of RPV. RPV filled by pure condensate. On June 15 film dosimeters (FD) of 3 workers of a contractor making preparation of manipulator for inspection of weldings in increased values of effective doses received by those workers which were 29.48, 9.13, and 5.18 mSv. Cumulated doses shown by operational electronic dosimeters (ED) however, were 0.259, 0.225, and 0.28 mSv. Investigations of discrepancies between two kind of dosimeters revealed that the workers put off ED during non-standardized work they had to perform out of scheduled workplan. The use of ED during the work was prescribed by the Work Order issued by the Rad. Protection Dept. of the NPP operator for this particular work. The cumulated effective dose for the year 2000 in case of worker, who received maximum was 32.11 mSv. In spite of the fact the NPP yearly limit, 20 mSv per year averaged over 5 years, was exceeded, the permitted effective dose in a single year, 50 mSv, however, was not exceeded. The effective dose received by the worker was classified as an "unplanned exposure" caused by violation of both, work and radiation protection procedures. The workers in question were temporarily forbidden to enter the controlled zone of the NPP and a written notification and information on the event was sent to the company management.

Location: BOHUNICE-4
Event date: Thu, 15-06-2000
Nuclear event report
Legenda & explanation