The OL3 plant unit’s boron pumps were turned on when driving down the plant unit

Report this content

The OL3 plant unit was driven down in accordance with the test production programme today at approximately 11 a.m. In connection with the planned shutdown, the boron pumps were turned on unexpectedly. The plant unit is in a safe state, and the reason for the boron pumps turning on is being investigated. The boron pumps’ function is to regulate the chain reaction.

The situation did not cause any harm to people or the environment.

During the test production phase of a nuclear power plant, the plant unit and its safety systems are tested to verify that the plant operations comply with design. The production tests also comprise planned reactor trips. The production forecast for the test production phase can be followed online at

For further information, please contact:
Johanna Aho, Head of Communications, Tel. +358 (0)40 729 0822


Teollisuuden Voima Oyj has produced electricity for its shareholders, Finnish industrial and energy companies, safely and reliably for over 40 years. Nuclear electricity generated at TVO's Olkiluoto plant covers approximately one sixth, increasing to nearly one third once Olkiluoto 3 is completed, of the electricity consumption in Finland. Climate-friendly nuclear electricity not only benefits society but also reduces the environmental impact of energy production. Moreover, the world's first final disposal facility for spent nuclear fuel is under construction in Olkiluoto.