The reactor pit liner structure, with the weight of 120 t and height of 9 m, was installed in the design position at power unit No.3 of Xudapu NPP being constructed under VVER-1200 Russian design in China.
The reactor pit liner acts as a permanent formwork during concreting for the further installation of the core catcher and the reactor vessel – key production operations during the unit construction. The reactor is installed in a concrete shaft, the equipment of which provides biological protection from the reactor core radiation, reliable fixation of the reactor taking into account seismic loads and thermal insulation along the outer surface.
“The peculiarity of the procedure was that the structure was installed in the design position with already mounted reinforcing bars for the future wall around. Due to this, it was possible to significantly accelerate the construction period”, – said Valery Kedrov, Director for Design of NPPs with VVER Reactors in China, Atomenergoproekt JSC.
The process of installing the structure of the reactor pit liner required special accuracy – the deviation from the axes of the reactor pit should not exceed 1 mm, and this is only one of a great number of strict requirements.
“Currently, despite strict restrictive quarantine measures, the works at the facility are being carried out in three shifts, in accordance with the schedule. By the end of 2021, the unit is on the way to start concreting the foundation slab of the steam chamber, the first floors of the security building and the auxiliary building, as well as pouring the lower walls of the control building”, said Aleksey Bannik, the Vice President for Projects in China of ASE JSC.
Xudapu NPP is a new project of cooperation between Russia and China in the field of nuclear energy, located in the city of Huludao (Liaoning Province). In 2019, a number of contracts were signed, including the General Contract for the construction of power units No. 3 and No. 4 of Xudapu NPP with VVER-1200 reactors, as well as a contract for the supply of nuclear fuel. In accordance with the contracts, the Russian party will design the “nuclear island” of the plant, supply key equipment for the nuclear island for both power units, provide designer supervision, installation supervision and adjustment supervision services for the equipment supplied. Commissioning of the units is scheduled for 2027-2028.