Resumption of Olkiluoto 2 nuke plant delays until Dec 20

The Olkiluoto nuclear power plant Unit 2, which was scheduled to resume operation early Monday now will be delayed until December 20, according to a press release issued by the owner of the plant TVO on Sunday.

A severe abnormal disturbance occurred at the Olkiluoto nuclear power plant Unit 2 on December 10, which led to shut down of the reactor.

Now the TVO needs permission from the Finnish Radiation and Nuclear Safety Authority (STUK) to resume the operation.

Prior to start-up, thorough inspections, maintenance and repair measures are carried out ensuring the function of all the systems.

The authority confirmed that the situation was caused due to hot water moving into the filters of the reactor water clean-up system.

Due to the water spraying of the containment, the equipment and systems inside it may be wet or may have been exposed to water.

Therefore, the important equipment and systems inside the containment are inspected especially carefully.

The authority will check electrical motors, sensors, connectors, transmitters, and limit switches.

It will inspect insulation, penetrations, and the cleanliness of the water in the suppression pool.

The company will do operational tests on the valves of the containment, in which the valves are moved and will test the maneuvering devices of the control rods and the reactor trip function.

Before restarting the plant unit, TVO will do a detailed investigation on the progression of events, as well as the necessary immediate measures to avoid a similar disturbance.

The STUK will give the permit for restarting the plant unit after completion of the measures.

TVO is preparing the application for the restart permit for STUK. The application includes a comprehensive report of the actions required before the restart and a safety evaluation.