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

26.4.2022

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 www.tvo.fi/ol3forecast.

* Update 4/26/2022 at 9:20 PM

In connection with the planned shutdown, the boron pumps (safety system) were turned on unexpectedly because of falsely tripped signal. The error in the automation system signal will be repaired and the commissioning program will continue as shown here: www.tvo.fi/ol3forecast.