Unit VI of the Kozloduy NPP enters scheduled annual overhaul on October 18 and nuclear refueling. During this period, an attempt will again be made to examine all problem tubes in the third steam generator of the unit. This became clear during a press conference organized by the Nuclear Regulatory Agency (NRA).
The analysis, which is done with special probes, is ordered for the second year under the NRA program, and the goal is to investigate the facts about the leaks. Last year, the regulator tried again to pinpoint exactly where the problem was, but research failed to find the problems, and a different drilling technology will now be used.
With the analysis, the NRA wants to understand which mechanisms influence the pipes to crack – vibrations, heat movement or others. – and to detect the defect before it developed into a crack, explained the chairman of the Agency Tsanko Bachiiski.
Leaks from the steam generator have been repeated several times in recent years and raise the question whether unit 6 needs a new steam generator, as well as whether the equipment for the “Belene“ to be used for which will be a legal analysis.
According to official information, there is currently less than 1% clogging, and the project documentation says that everything is fine up to 5% clogging of the pipes.