The final physical start-up stage of the innovative power unit 6 with a VVER-1200 reactor was launched at Leningrad NPP (part of the Rosatom State Corporation Electric Power Division). Power unit 6 has been brought to the minimum controllable power level for the first time.

This means that neutron flux control equipment recorded steady neutron power and a self-sustaining controlled nuclear chain reaction has started in the reactor core for the first time.

“The minimum controlled power level will allow us to safely perform a number of tests and verify that the physical characteristics of the reactor core meet project requirements. Once we complete these operations and Rostekhnadzor receives the calculations, we will only need to obtain a permit for the power start-up and begin the gradual power ascension,” Leningrad NPP-2 Chief Engineer Alexander Belyaev said.

Within a week more than 50 tests will be conducted on the unit in accordance with the physical start-up program. These tests will allow to verify the neutronics characteristics of the first reactor fuel charge obtained through the calculations as well as to confirm the reliability of functioning of protection features, interlocks and the entire nuclear physics monitoring and nuclear safety systems of the reactor.

The commissioning of the VVER-1200-enabled unit 6 is carried out in stages and started on July 19, 2020, when the first fuel assembly with fresh nuclear fuel was loaded into the reactor. At the subsequent stages, during the power start-up, trial operation and integrated testing of the unit, all equipment will undergo final inspection at operational parameters, with the delivery of electrical and thermal energy.

The power unit 6 with VVER-1200 reactor is scheduled to be commissioned in 2021. It will replace the RBMK-1000 reactor-equipped power unit 2 of Leningrad NPP-1, which will be shut down at the end of this year after 45 years of service.