Rosenergoatom already learning from BN-800

The BN-800 fast-neutron reactor at Beloyarsk unit 4, which is scheduled to begin commercial operation by the end of this year, is already providing operating and technological experience of value to the development of the planned BN-1200 fast-neutron reactor at Beloyarsk unit 5, according to Michael Bakanov, director of the Beloyarsk plant.

Beloyarsk 4 is fuelled by a mix of uranium and plutonium oxides arranged to produce new fuel material as it burns. Its capacity exceeds that of the world's second most powerful fast reactor - 560 Mwe Beloyarsk 3. Russia plans to build a BN-1200 fast reactor power unit at Beloyarsk to start up by 2020.

"BN-800 is the successor to the BN-350 and BN-600 reactor units," Bakanov said. "But the fact it has a large number of structural and technological improvements means it has trial status, like all the previous BNs. The priority of the BN-800 then is not so much the production of electricity."

"It's a commonly known fact that the economics of a trial design are inferior to a serial product, in this case a commercial VVER. The main objective of the BN-800 is [to provide] operating experience and technological solutions that will be applied to the BN-1200."

The 789 MWe BN-800 is also providing valuable information and data for the development of fast-neutron reactor coolant and fuel, Valery Shamanskiy, deputy chief engineer at the plant, added in the same statement issued by Rosenergoatom last week. Rosenergoatom is the civilian nuclear power plant operating subsidiary of Russian state nuclear corporation Rosatom.

These potential improvements are already underway, Shamanskiy said. "Literally from the day of its inception, the Beloyarsk 4 fast-neutron reactor has provided a large amount of knowledge and experience that has no parallel anywhere else in the world."

The Beloyarsk nuclear power station, which is in the Sverdlovsk region in central Russia, has two shut down reactors and one in commercial operation - Beloyarsk-3. The Beloyarsk-5 BN-1200 will use larger fuel elements than the BN-600 and BN-800 and have a simplified refuelling procedure.

Fundamental features of the BN-800 reactor include an active reactor protection system with a passive system that works automatically in the event of loss of sodium-cooling liquid pressure, Rosenergoatom said. During normal operation, the reactor's control rods float in the cooling liquid on top of the reactor core. If the pressure of the cooling liquid dropped, the rods would fall into vertical control rod channels in the reactor core and stop a chain reaction by absorbing neutrons. It also has a passive supplementary air cooling system, used to remove of residual decay heat.

Researched and written
by World Nuclear News