Russia’s Novovoronezh NPP (NVNPP) has received permission from the Federal Service for Ecological, Technological and Nuclear Supervision (Rostekhnadzor) for the final stage of work to transfer VVER-1200 reactor at unit 6 to an 18-month fuel cycle, Rosatom’s fuel company TVEL has said. Novovoronezh 6 will be the world’s first VVER-1200 to make this transition, which will significantly reduce the duration of repairs, boost electricity generation, and increase overall efficiency. The unit is currently operating on an 18-month fuel cycle as part of a pilot programme.

“The innovative design of unit 6 makes it possible to implement more efficient fuel cycles,” explained Evgeny Golubev, head of NVNPP’s Nuclear Safety and Reliability Department. “Almost immediately after the commissioning of these new VVER-1200 power units, Rosatom began to develop the justification for the safety of their operation in an 18-month fuel cycle. We started work in this area at Novovoronezh NPP back in 2017.”

He said unit 6 has already completed four 18-month fuel campaigns since. “The equipment of the power unit and the nuclear fuel manufactured by TVEL Fuel Company have proved to be satisfactory during this time. Rostekhnadzor confirmed the reliable and safe operation of the unit and approved the licence change for continued pilot operation,” he added.

The move to an 18-month fuel cycle involves a phased transition (pilot operation) to a special version of VVER-1200 fuel for extended cycles (it differs in the level of uranium enrichment, as well as profiling for a burnable gadolinium absorber). Over several fuel campaigns, specialists gradually remove old fuel and load new fuel. Each of these stages is monitored by Rostekhnadzor.

Now the fifth and last pilot fuel campaign in the 18-month fuel cycle has begun, after which another report will be submitted to Rostechnadzor. Provided this is completed successfully, unit 6 will then move to a permanent 18-month fuel cycle.

Image: Novovoronezh 6 will be the world's first VVER-1200 to move to an 18-month fuel cycle (photo courtesy of Rosenergoatom)