Annual outages brought forward in Olkiluoto due to fuel damage

29.4.2019

Annual outages at the operational plant units in Olkiluoto will be started four days earlier than originally planned. The reason for this is the need for procedures needed at the unit Olkiluoto 2 to remove damaged fuel from the reactor. Some amount of radioactive substances are released from damaged fuel into reactor water. This does not cause any risk to the environment.

The annual outages will start on Wednesday, May 1st while original plan was to begin on Sunday, 5 May. The plant shutdown procedures will begin on Wednesday at 21:00 and the plant unit will be disconnected from electricity production at 23:00. According to the schedule, OL2 annual outage will be completed on Sunday, May 26th.

In addition to refuelling, significant works include the pressure test of primary circuit, renewal of the heat exchanger in the purification system of reactor water, the renewal of the low voltage bushings in the containment and the renewal of the 400 kV switchgear. Damaged fuel assemblies will be removed from the reactor and replaced with fresh fuel.

The annual outage carried out at the OL1 plant unit is a refuelling outage. It will start on Sunday, 2 June, and is scheduled to complete on Tuesday, 11 June. Refuelling is the most important activity for this outage.

Olkiluoto nuclear power plants are kept in good condition all the time by means of annual refuelling and maintenance outages carried out in turns at the plant units.

For more information, please contact:
Marjo Mustonen, Senior Vice President, Electricity Production,
tel. +358 2 8381 2100.

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