A visit to OL3 in 2020 (image credit: IAEA Imagebank, CC BY 2.0 license).
Incident Report: Coolant Leakage at Olkiluoto Nuclear Facility
On March 10, Teollisuuden Voima Oyj (TVO), the operator of the Olkiluoto Nuclear Power Plant located on Finland’s west coast, announced a leak of reactor coolant.
The incident involved approximately 100 cubic meters of reactor coolant leaking from the Olkiluoto 3 (OL3) reactor during filling operations for the reactor pool. Fortunately, this spillage flowed into containment areas insulated from environmental contact and into the facility’s floor drain system. TVO assured that there was no immediate threat to personnel, environmental safety, or overall nuclear safety.
Scheduled Maintenance and Incident Details
The planned maintenance outage commenced at OL3 on March 1 and is set to continue until early May. Progress in these maintenance tasks has adhered to the established timeline. However, on March 7, an unexpected event transpired when radioactive coolant was inadvertently released within some containment rooms during ongoing maintenance activities.
This particular leakage was attributed to human oversight; a hatch intended for sealing off the reactor pool had not been properly secured. In response to this occurrence, TVO stated that steps taken effectively mitigated any potential radiation safety risks.
Response Measures and Waste Management Protocols
TVO clarified via press release that contaminated wastewater will be treated according to stringent protocols utilizing designated systems for safe disposal. Immediate cleaning efforts were launched within affected containment areas while staff received guidance on necessary alterations concerning access protocols.
Understanding Reactor Coolant Systems
*Reactor coolant functions by being heated in a pressure vessel before circulating through piping systems toward steam generators where it transfers heat efficiently into a secondary circuit. Once cooled after passing through steam generators, it returns back into the pressure vessel.
