Annealing of reactor pressure vessel of Armenia’s NPP in Metsamor completed

YEREVAN, August 6, /ARKA/. The annealing of the reactor pressure vessel of Armenia’s nuclear power plant in Metsamor has been completed, Russian Rosatom corporation, the main contractor of the operation, said today.

It said the annealing is a key stage of the scheduled preventive maintenance of the facility to extend its service life.

“The annealing process took place in the reactor hall of the plant with the reactor remaining in its original place. The annealing installation was delivered to the nuclear power plant disassembled, then assembled and installed in the reactor vessel. The reactor pressure vessel was heated to 475 degrees Celsius using an annealing unit and kept in that state for 150 hours and then allowed to cool slowly. Direct heat treatment of the reactor pressure vessel metal took a week,” Rosatom said.

The annealing has recovered the operational characteristics of the metal shell of the reactor to its original state by 80-85%. The implementation of this procedure will enable to operate the Armenian NPP until 2036, according to Rosatom.

The CEO of the nuclear power plant Eduard Martirosyan noted that the Armenian NPP is a guarantee of security and development of the Armenian economy.

“The reliability and serviceability of the reactor pressure vessel largely determines the safety of NPP operation as a whole. Thanks to the experience and high competencies of Russian specialists, the key work for the extension of the plant’s life was quite successful,” he said.

The annealing was handled by JSC Rosatom Service, a division of the Russian State Atomic Energy Corporation Rosatom in cooperation with Armenian and Russian specialists.

According to Yuri Sviridenko, the project manager, this became possible only thanks to the well-coordinated work of the Armenian and Russian scientists. And we hope that the result of our joint efforts will further improve the safety of the nuclear power plant and extend it until 2026, and in the future for another 10 years,” he stressed.

Annealing is recognized all over the world as an effective way to ensure the safe and reliable operation of reactor facilities. For the first time this procedure was applied in 1987 at the third power unit of the Novovoronezh NPP in Russia.

Annealing has already been carried out at VVER-440 reactors Kola NPP (Russia), Rovno NPP (Ukraine), Kozloduy NPP (Bulgaria) and Loviisa NPP (Finland).

The Armenian NPP was brought to a halt for preventive maintenance on May 15. It will last 141 days, as part of a project designed to modernize and extend its service life.

The Armenian nuclear power plant, the only one in the South Caucasus region, is located near the town of Metsamor, about 30 km west of Yerevan. It annually generates up to 40% of all electricity in Armenia. -0-