Russian regulator Rostekhnadzor on 6 November issued a permit for the start of the pilot operation of unit 2 of the Leningrad-II NPP (also known as Leningrad 6), according to nuclear utility Rosenergoatom. Specialists will now begin a phased increase in the reactor power. “Pilot operation is the final and longest test of a power unit before commissioning. It will last about four months,” Rosenergoatom explained.
During this time, the specialists will increase the power of the reactor plant to 40%, 50%, 75%, 90% and 100% and will carry out almost 200 tests of the unit's technological systems and safety systems. "After reaching 100% capacity, completing all the prescribed tests at each power level, flawless and continuous operation for at least 15 days, the power unit will be shut down to check the equipment and prepare it for commercial operation, after checking by the state commission," explained the chief engineer of Leningrad NPP-II Alexander Belyaev .
The first fuel assemblies were loaded into the reactor core in July after which the unit was brought to the minimum controlled power, and was submitted to a series of tests. The unit was connected to the grid on 22 October. Formal commissioning is scheduled for 2021.
Leningrad 2 RBMK reactor is shut down
The existing Leningrad NPP in Sosnovy Bor with four RBMK-1000 units is to be replaced by Leningrad-II with four VVER-1200 units. Leningrad unit 1 was shut down for decommissioning on in December 2018 after Leningrad-II unit 1 was connected to the grid in March 2018.
Leningrad-II 2 is replacing Leningrad 2, which was closed down on 10 November after being in operation for 45 years. However, in line with Russian regulations, the RBMK unit will considered to be in operation without generation until all its fuel has been removed, which will take approximately four years. During this time, a project for the decommissioning of the unit will be prepared.
Leningrad 2 will undergo regular maintenance similar to unit 1. “In fact, the procedures performed practically do not differ from ordinary repairs,” said plant director Vladimir Pereguda. “Now our task is to also reliably and safely service the shutdown units, unload nuclear fuel from reactors, prepare them for transfer to the specially created enterprise, Experimental Demonstration Engineering Centre (ODIC RBMK).”
The change over to the new generation plants has gone smoothly with no loss of power production. “The replacement of retired capacities will be imperceptible for electricity consumers,” noted Rosenergoatom General Director Andrey Petrov.
The Leningrad NPP was the first plant with RBMK-1000 reactors (uranium-graphite channel reactors). The decision to build it was made in September 1966. The design life of the RBMK-1000 was initially 30 years, but after a large-scale programme of inspections, justifications, and upgrades, the service life of each of the four Leningrad units was extended for another 15 years. The modernisation involved 90% of the systems and equipment of RBMK-1000s, and, in terms of safety, they fully comply with international requirements, Rosenergoatom said.
