Concreting of the structural contour walls for the reactor building at unit 2 of Russia’s Kursk II NPP has begun a month early, the plant announced on 9 August. Kursk II is a replacement station comprising two units with a capacity of 1255MWe each using VVER-TOI reactors. The general designer is Atomenergoproekt (part of the ASE Group) and the general contractor is the ASE Group. VVER-TOI is an evolutionary development based on the generation VVER-1200 reactor. “The experience gained at the first power unit helped save time. It acted as a template enabling us to make the right decisions,” explained chief engineer Alexey Volnov. “We managed to optimise the processes, remove all the flaws. As a result, we finished concreting the foundation slab two weeks earlier. And we’re now ahead with the contour walls.” Contour walls support of the entire power unit. “We have a double wall. It is designed to protect against both internal and external influences,” he added. “The thickness of the outer wall is 1200 millimetres, and of the inner wall is 400 and 600 millimetres. At the moment, we have already laid over 800 cubic meters of concrete.” In total, more than 1,400 cubic metres of concrete will be laid in the structural walls. Builders plan to finish them in October.