The reactor vessel metal and the in-vessel devices have been inspected at Unit 1 of the Kalinin NPP using a modular delivery manipulator and television guidance system. This was the first time when this equipment was used at Russian pressurized water reactors.
According to Maxim Milyaev, deputy head of centralized repair shop at the Kalinin NPP, this device enables all types of non-destructive testing automatically without using a polar crane and a reloader, caters for vertical and horizontal camera movement and 360-degree rotation.
‘The manipulator’s capabilities let us considerably simplify the control procedure, reduce the radiation burden on the operating staff. Its main advantage is the speed of surface scanning and excluding operations related to camera relocation, which helps to reduce the amount of time required for the unit’s maintenance and save up to 65 million rubles per year’, Mr. Milyaev noted.
The vessel reactor and welded seams inspections are designed to detect the parameters of the base metal that is exposed to high temperature, pressure and ionizing radiation for a prolonged period of time. Additionally, this is the only piece of equipment at a nuclear power plant that doesn’t have to be replaced.
‘The outcomes of the metal television-measurement and visual diagnostics demonstrate that the cylindrical belt and the reactor floor as well as in-vessel devices fully comply with the design parameters and the safety standards. This is the key factor of obtaining a license to operate the unit for an extended period of time’, Alexander Dorofeev, chief engineer at the Kalinin NPP, said.
It is important to note that Unit 1 of the Kalinin NPP was stopped in November 2019 to conduct full-scale maintenance and upgrade as a part of the industrial program of extending the unit’s lifespan. As of now, the Rostekhnadzor license lets it run on an extended timeline until 2025. Following the completion of all operations, its life spanmay be extended until 2044.