India’s Kudankulam nuclear power plant (KNPP) in Tamil Nadu has been supplied the first batches of the new TVS-2M nuclear fuel, enabling an elongation of the fuel cycle from 12 to 18 months for its operating Russian designed VVER-1000 reactor units 1 and 2, according to an announcement made by the Russian state atomic energy corporation Rosatom subsidiary, TVEL Fuel Company.
A TVEL statement last week said that after refueling in July 2022, the KNPP unit 1 will start operating in the 18-month cycle, instead of the 12-month cycle permitted by the currently used UTVS fuel.
“With this, TVEL will be fulfilling the agreement with India’s Department of Atomic Energy / Nuclear Power Corporation of India Limited (NPCIL) on implementation of TVS-2M nuclear fuel with 18-month operating cycles for KNPP”, the statement said.
Rosatom is the equipment supplier and technical consultant for the KNPP being operated by the state-run NPCIL. As per an intergovernmental agreement, Rosatom is similarly collaborating in the construction of four more units at Kudankulam – 3, 4, 5 and 6 – of 1,000 MW capacity each. Units 1 and 2 were commissioned in 2013 and 2017, respectively.
As compared to the UTVS fuel earlier supplied for the two operating Kudankulam reactors, the TVS-2M fuel assemblies have a number of advantages, making them more reliable and cost-effective, the statement said.
“First, it is the rigidity of a bundle — because of the welded frame, the fuel assemblies in the reactor core retain their geometry, the spacer grids protect the fuel rod cladding from fretting wear (preventing from depressurization), and the additional spacer grid makes fuel assemblies more vibration-resistant”, the statement said.
“Secondly, the new fuel has increased uranium capacity — one TVS-2M assembly contains 7.6 percent more fuel material as compared to UTVS. Besides, the special feature of the Kudankulam fuel in particular is the new generation anti-debris filter ADF-2, efficiently protecting fuel assemblies”, it added.
According to TVEL, operation in longer fuel cycles also enhances the economic efficiency of a plant since reactors have to undergo stoppage and refueling less frequently, allowing the power units to produce more electricity. Moreover, the power plant needs to purchase less fresh fuel, and as a result, has to deal with smaller amounts of spent nuclear fuel.
“We offer to our foreign clients the solutions which have proved successful at the Russian nuclear power plants. TVS-2M fuel is efficiently operated in 18-month fuel cycles at Rostov NPP and Balakovo NPP in Russia, as well as at Tianwan NPP in China”, TVEL’s Senior Vice President for Research and Development, Alexander Ugryumov, said in a statement
“Fuel bundles with ADF-2 anti-debris filters have also shown good results at Rostov NPP. Besides, all VVER-1000 reactors in Russia operate at higher capacity, 104 percent of the nominal, and this experience is also a matter of interest for nuclear power plants operators abroad”, he added.
Ugryumov had earlier told Nuclear Asia that the TVS-2M fuel assembly offers increased uranium capacity, improved heat reliability and enhanced operational safety. While UTVS are packed with 490 kg of enriched uranium pellets, the TVS-2M bundles weigh 527 kg, allowing a nuclear plant operator a lot of options in terms of an extension of a fuel cycle length from 250 up to 510 effective full-power days, he had said.
