At power unit No. 4 of the Beloyarsk NPP, where the BN-800 reactor operates, the modernization of the protection system for the evaporative modules of steam generators has been successfully completed. As part of the work, modern impulse safety devices manufactured in Russia were installed. The work was carried out by specialists from the Beloyarsk NPP with the participation of the Chekhov Energy Engineering Plant.
Evaporative modules of the steam generator are a key component of the station: it is here that steam is generated, which rotates the turbogenerator and generates electricity. Every second, 292 kilograms of steam pass through the equipment under a pressure of 13.7 megapascals, which is 135 times higher than normal atmospheric pressure. The new safety valves are designed to operate reliably in such extreme conditions.
Previously, the design of the impulse safety devices was horizontal and under constant pressure, which could cause leaks when closing. Now, engineers have switched to a vertical layout and changed the principle of operation: the valve opens by a steam impulse, and not by releasing internal pressure.
The replacement of 42 valves was carried out in stages. The first devices were installed back in 2019, and over the years of trial operation, they have confirmed high reliability. This gave the green light for a complete modernization of the system, which has now been completed. The expected service life of the new impulse safety devices is 45 years.