Russian reactor shell with 120 years life may be used in Kudankulam

Chennai: Russia has developed an extra strong nuclear power reactor shell that can increase the reactor life up to 120 years and which can also be used in reactors to be set up in Tamil Nadu`s Kudankulam.

"After a considerable research effort, the Central Research Institute for Machine Building Technology (a subsidiary of Atomenergomash, Rosatom`s nuclear engineering division) has developed a new, ultra-pure steel grade for the VVER-TOI core shell," Russian nuclear power corporation Rosatom said in a statement on Monday. 

"The pilot shell was produced at OMZ SpetsStal with technological support from OMZ Izhora, which also did the testing of the new material," it added.

The extra-strong shell for the VVER-TOI reactor has been for the first time produced in Russia to increase the reactor vessel life up to 120 years.

The extra strength of the reactor shell is attributed to a new nickel-alloy steel grade, said Alexander Romashkin, the acting deputy director of the Metallurgy and Engineering Institute affiliated with the Central Research Institute for Machine Building Technology.

To manufacture the shell, a 420-ton ingot was cast for the first time after the collapse of the Soviet Union.

The ingot was then forged into a record-large shell, 6m high and 4.5m in diameter. As it has no weld seams, it will be used as a part of the reactor vessel which is most intensively bombarded by neutrons.

Extension of the reactor vessel life is a key trend in the nuclear power industry.

While the reactors operated in Russia have a service life of 60 years, new VVER-1200 reactors to be installed at Novovoronezh NPP and Leningrad NPP-2 will work for 100 years.

Achievements of the Central Research Institute for Machine Building Technology will make reactors live more.

"Development of the new steel grade proves that OMZ SpetsStal, supported by the Central Research Institute for Machine Building Technology, is now able to produce reactor shells of required dimensions and properties," Romashkin was quoted as saying in the statement.

No decision has been made yet where to use the reactor shell.

"It can be used in any VVER-TOI reactor vessel, including those to be installed at Akkuyu and Kudankulam nuclear power plants", he adds.

In Russia, VVER-TOI reactors will be installed at Kursk NPP-2 (by 2020-2022) and Smolensk NPP-2 (by 2027). VVER-TOI reactors will give Rosatom a competitive advantage over its global peers.

The next step will be to set up production of reactor shells at Energomashspetsstal (a subsidiary of Atomenergomash, Rosatom`s nuclear engineering division). This is a plant where a pilot VVER-TOI shell was produced a year ago. The pilot shell was shipped to Atommash in Volgodonsk.