Unplanned irradiation of employee during performance of routine walk-down in the controlled area

Nuclear Facility: Unit 5, Kozloduy NPP

Event Title: Unplanned irradiation of employee during performance of routine walk-down in the controlled area

Event description:

In accordance with the requirements of internal documents a visual inspection of the equipment in the containment of the reactor is carried out weekly. The aim of the visual inspections is to early identification of leaks from seals of pipes and equipment. For the performance of the visual inspections route-maps are developed.

On 04.11.2009 was performed a routine walk-down in the containment of Unit 5. Organizational requirements for briefing and access are met.

After completion of the walk-down the check of the individual dosimeter of one of the employees was determined that he received a dose of 2,06 mSv, which exceeds individual daily intake permitted by internal documents of the NPP. Additional measurements are made to the employee and no internal contamination was found out.

The received dose doesn’t exceed the reference value in the Regulation on basic norms of radiation protection (limit of effective dose for the staff for a year can not exceed 50 mSv).

A commission to clarify the circumstances led to the exceeding of the daily dose was designated.