At the construction site of Russia’s Kursk II nuclear power plant, the truss console has been installed under the reactor shaft of unit 2. This component, weighing 145 tons and with a diameter of more than 9 metres, is the second part of the core melt trap, Kursk NPP said.

With this achievement, one of the two tasks for 2020 has been completed. “We are continuing to build the safety system at the second power unit of the replacement station,” said Kursk NPP director Vyacheslav Fedyukin. “The melt trap is a domestic technology that relates to beyond design basis accident management systems.”

The melt trap has three parts: a body, a truss console, and a guide plate. The reactor building already houses the body, which is filled with unique material, consisting mainly of iron and aluminium oxides, which, when dissolved in molten fuel will reduce its energy release.

The truss console was installed on a 7m-high reactor shaft. Its main purpose is to organise communications – water supply, steam removal, ventilation, and routes to enable measuring instruments for examining the melt localisation device.

Once pipes and service corridors have been welded, the builders will install the guide plate, which is intended to protect the entire structure from the thermal effects of corium.

General contractor ASE also announced in June that the reinforced block of the reactor shaft at Kursk II-2 had been mounted and concreted in position. The weight of the block after concreting amounted to more than 90 tons, and its diameter is almost 12 metres. Concreting work was carried out by employees of the Kursk branch of Trest RosSEM.

“After concreting is completed, we will begin to carry out the following work on preparing for the most important stage of construction – installing the reactor vessel,” said Maxim Latyshev, deputy director of  ASE IC for the construction of Kursk II.

In mid-May, builders also finished concreting the foundation slab of the turbine building for unit 2, and started building the underground part of the columns of the foundation of the turbine unit.

“Work on the construction site is on schedule,” said Igor Kuzmenko, chief engineer of the capital construction department at Kursk II. “Compliance with the construction schedule is assessed by the execution on time of work called key events. In total, five key events have been completed since the beginning of 2020.”

Kursk II is a replacement station for the current Kursk nuclear plant. Commissioning of the first two units with the new design VVER-TOI reactors will be synchronised with the decommissioning of Kursk 1&2 of the operating plant.

Photo: The truss is installed at Kursk II  (Credit: Rosenergoatom)