The event at Olkiluoto nuclear power plant yesterday caused no threat to the safety of people or environment

The Radiation and Nuclear Safety Authority (STUK) has continued the oversight of the situation during the night. The radiation situation at the plant and in the environment is normal. No radioactivity was  released  that would have had any impact on people or environment. The plant personnel have neither been exposed to radiation.

The cause for the event yesterday was a fault in the purification system for the reactor cooling water. Contaminated filter material got into the cooling circuit and caused a temporary rise of the radiation levels in the circuit. The fuel was not damaged, consequently there was no risk of harmful radioactive release.

The increased radiation levels in the cooling circuit initiated the automatic safety systems. The staff started in accordance with the instruction measures for protecting people and to sort out the situation.

STUK will continue the enhanced oversight of the corrective actions at Olkiluoto unit 2. Teollisuuden Voima has ended the emergency standby and is working according to standard procedures.