Russia’s Novovoronezh NPP has completed a pilot 18-month fuel cycle industrial operation at unit 6 and has submitted the relevant documents to the Federal Service for Environmental, Technological & Nuclear Supervision (Rostechnadzor). After receiving an expert opinion and changing the terms of the licence, unit 6 will now be transferred to commercial operation of an 18-month fuel cycle.
Since the unit was commissioned in 2016 it has carried out three fuel campaigns in a 12-month cycle with some used fuel being replaced with new assemblies once a year. In August 2020, pilot production began with an 18-month fuel cycle for the fourth and fifth campaigns. The plant said equipment at unit 6 and the nuclear fuel produced by TVEL proved to be reliable, safe and efficient.
Novovoronezh NPP was the first nuclear plant in Russia to host VVER-type reactors (light water-cooled pressurised reactors) and its reactors are leading VVER prototypes. Unit 1 was commissioned in 1964 (VVER-210), unit 2 in 1969 (VVER-365), unit 3 in 1971 (VVER-440), unit 4 in 1972 (VVER-440), and unit 5 in 1980 (VVER-1000). Units 1&2 were shut down in 1984 and 1990 and unit 3 in 2016. Unit 1 of Novovoronezh II (a VVER-1200, also known as Novovoronezh 6) began commercial operation in February 2017 and unit 2 (Novovoronezh 7) in November 2019.
“The design of units 6&7 at Novovoronezh NPP made it possible to improve the fuel cycle,” said Plant Director Vladimir Povarov. “This makes it possible to significantly reduce the duration of repairs, ensure an increase in electricity generation, and also increase the efficiency of the power unit as a whole,” he added.
Increasing the duration of the fuel cycle was made possible by increasing the average enrichment of nuclear fuel and using more gadolinium oxide as a neutron absorber in the fuel assemblies for the VVER-1200 reactor plant.
“We work not only on design changes, but also on increasing the efficiency of the fuel cycle, without lowering the safety bar,” noted Alexander Shutikov, General Director of nuclear utility Rosenergoatom. “The experience Novovoronezh workers gained during the implementation of the 18-month fuel cycle at a unit with a VVER-1200 reactor, will be used on units of a similar design both in Russia and abroad.” Similar work is being carried out at power unit 7 and its transition to an 18-month fuel cycle is scheduled for March 2024. As a result of introducing modern fuel with increased uranium content, all VVER-1000 reactors are already operating at 104% of the nominal power in extended 18-month fuel cycles.
Image: Novovoronezh unit 6 previously operated in a 12-month fuel cycle (courtesy of Rosatom)
