Russia’s Siberian Chemical Combine (part of the Fuel Company TVEL) has developed an alloy and manufactured components for a metrological fuel assembly (MFA) for the fast neutron reactor BN-800 at unit 4 of the Beloyarsk NPP. "The MFA will be used during first power of BN-800 to calibrate measurement channels of the reactor sector system," according to a FC TVEL statement of 7 April. The MFA is similar in appearance to the existing FAs for the BN-800. However, it holds fuel rod dummies instead of standard fuel rods. These dummies make it possible to evaluate how the standard fuel assembly would behave in normal operation.
Several enterprises participated in the development and manufacture of the MFA. SCC was charged with development of the metallic alloy production technology for its components and their manufacture. It took about two years to develop the assembly and seven months were needed for manufacture (September 2015 – March 2016).
Experts estimate that the alloy produced by SCC’s chemical and metallurgical plant "can impart structural strength and necessary chemical inertness to the MFA components". The alloy was used to make 37 components, and they were sent to the Research Institute of Atomic Reactors (NIIAR) in Dimitrovgrad where the MFA was put together.
Meanwhile, Beloyarsk 4’s BN-800 reactor has been shut down for final repairs before ramping up to its rated power, the plant said. The BN-800 was first connected to the grid in December 2015 after which power was gradually increased. In March it was operating at 85% power and tests were carried out on 2 April before the unit was shut down. Commercial operation is planned by the end of 2016.