Russia has completed the loading of 163 fuel assembly simulators (ITVS) into unit 4 of the Rostov nuclear power plant, a VVER-1000 under construction at the Rostov site, which is near the city of Volgodonsk.

The ITVS simulate the geometry of the core of the reactor, confirm the hydraulic characteristics of the reactor installation in the case of circulation washing and for cold and hot testing of the reactor.

Unit 3 was connected to the grid in December 2014, while the reactor pressure vessel was installed at unit 4 in December 2015.
Source: World Nuclear News