Incident at Olkiluoto 3 nuclear power plant in Finland exposed personnel to radiation

In June, an incident involving radiation exposure occurred at the Olkiluoto 3 nuclear power plant. Teollisuuden Voima (TVO) reported that four personnel were briefly exposed to high radiation dose rates during maintenance work on a lifting device. Fortunately, there were no injuries resulting from the incident.

The test fuel assembly used for the operation contained no nuclear fuel but included a control rod that had been used in the reactor and was radioactive. The investigation identified several contributing factors to the incident, including unclear responsibilities, insufficient administrative procedures and guidelines, as well as communication failures. There were also no technical barriers to prevent the test assembly from being lifted above the water surface.

In response to the incident, TVO initiated measures to prevent similar occurrences in the future. Moving forward, all work involving the handling of test assemblies will be governed by the same administrative requirements as those for actual fuel handling. TVO has submitted a report on the incident to the Radiation and Nuclear Safety Authority (STUK).