Unit 4 at Russia's Rostov nuclear plant reached criticality and minimum controlled power on 29 December.
The unit is now in the final stage of commissioning, with the integrity and function of all operation and safety systems already verified and tested. Measurements of the neutron-physical characteristics of the reactor core to comply with design parameters and a full testing programme of the reactor control and protection systems. The unit will supply some electricity to the grid during these tests after which it will begin commercial operation and be handed over to nuclear utility Rosenergoatom.
Rostov 4 is a 1,000MWe MWe VVER pressurised water reactor. Construction of units 1 and 2, also VVER-1000s, began in the 1980s but construction was suspended, and they finally began commercial operation in March 2001 and October 2010. Rostov 3 was connected to the grid in December 2014. Rostov 4 is Russia's 36th reactor.
Photo: Operating staff celebrating first criticality at Rostov 4 (Credit: Rosatom)