India’s Kudankulam Nuclear Power Project (KNPP) in Tamil Nadu will use the new TVS-2M nuclear fuel and an elongation of the fuel cycle from 12 to 18 months for both its operating VVER-1000 reactors, according to an announcement made by the Russian state atomic energy corporation Rosatom subsidiary. the TVEL Fuel Company.
Rosatom is the equipment supplier and technical consultant for KNPP being operated by the state-run Nuclear Power Corporation of India Ltd (NPCIL). As per an intergovernmental agreement, Rosatom is similarly collaborating in the construction four more units at Kudankulam – 3, 4, 5 and 6 – of 1,000 MW each. Units 1 and 2 were commissioned in 2014 and 2017, respectively.
A TVEL statement said a supplementary agreement to the fuel supply contract has been signed with NPCIL to implement a comprehensive engineering project, including introduction of the new TVS-2M nuclear fuel and elongation of the fuel cycle from 12 to 18 months for both the operating VVER-1000 reactors of Kudankulam NPP.
As compared to the UTVS fuel model, which is currently supplied to 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 depressurisation), and the additional spacer grid makes fuel assemblies more vibration-resistant. Secondly, the new fuel has increased uranium capacity – one TVS-2M assembly contains 7.6 per cent more fuel material as compared to UTVS,” it added.
“Everything that we offer to our Indian partners is focused on obtaining economic benefits from nuclear power units operation. The efficiency is achieved due to the increased uranium content in a fuel bundle, reducing the amount of spent nuclear fuel and increasing duration of the fuel campaign from three to four and a half years,” said TVEL Fuel President Natalia Nikipelova.
According to the statement, TVEL has successfully implemented similar projects of replacement UTVS with TVS-2M fuel and an extension of the fuel cycle from 12 to 18 months at the Tianwan Nuclear Power Project in China.
With the the original 10-year fuel supply agreement for KNPP a few years back, TVEL Vice President (R&D) Alexander Ugryumov had earlier told Nuclear Asia that at the time of negotiating for KNPP units 1 and 2, the company only had the international licence for the UTVS fuel loaded into the VVER-1000 type reactors.
“The UTVS fuel was applied to all international projects of Rosatom, including units 1 and 2 of the Tianwan Nuclear Power Plant in China and unit 1 of the Bushehr NPP in Iran. We now have the licence to sell TVS-2M, which is the reference solution for all power units with VVER-1000 reactors which Rosatom builds abroad. From the very beginning, TVS-2M will be loaded into the reactors of the Kudankulam units 3, 4, 5 and 6,” he had said.
Ugryumov also said the TVS-2M fuel assembly offers increased uranium capacity, improved heat reliability and enhanced operational safety, while supply agreements had already been reached in principle.
“Upgrading to TVS-2M will help improve efficiency of the Indian VVER units as well as reduce the cost of electricity. Being more robust, with higher stiffness, this fuel bundle does not bow in the reactor and preserves its initial shape, making operations safer and reliable,” he said. “While UTVS are packed with 490 kg of enriched uranium pellets, TVS-2M bundles weigh 527 kg. For a nuclear plant operator it gives a lot of options in terms of an extension of a fuel cycle length from 250 up to 510 effective full-power days,” he added.
The new solution is also more efficient in terms of economy. “This is because you save the amount of money spent on the scheduled outages, while still providing the highest safety standards. Secondly, with more uranium mass you will need less fuel bundles to generate electricity, so after the end of the operation there will be less spent nuclear fuel”, Ugryumov said.
The advanced TVS-2M fuel assembly can be used for three cycles lasting a total of 54 months, instead of the current duration of 36 months.