The Petrozavodskmash plant (part of Rosatom’s Mechanical Engineering Division) has begun shipping main circulation pump casings (GTsN – Glavnikh Tsirculyatsionnikh Nasosov) for unit 8 of China’s Tianwan NPP.
Mechanical engineers have manufactured and shipped to the construction site the first of four pumping units that will be installed in the reactor hall. During the manufacturing process, the pump casings undergo all necessary types of quality control, including x-rays, and various tests, the most important of which are hydraulic tests with excess pressure (24.5 MPa). After receiving acceptance based on the results of these inspections, the equipment is considered ready for shipment.
Rosatom is implementing two nuclear power plant construction projects in China – two VVER-1200 units at the Tianwan NPP (7&8) and the Xudabao NPP (units 3&4). Almost all enterprises of the Mechanical Engineering Division are involved in this work. Equipment for the reactor and turbine rooms is manufactured at various production sites. To date, all reactor vessels for the new units of the Tianwan and Xudabao NPPs have been shipped from the Atommash production site in Volgodonsk, and a complete set of main circulation pumps for Tianwan 7 has been shipped from Petrozavodsk. The production of steam generators for Xudabao 4, main circulation pump units for the Tianwan NPP, and other equipment for the two NPPs is underway.
The main circulation pump is an important and integral part of the reactor installation: it provides intensive circulation of coolant in the primary circuit of the reactor and operates under a pressure of about 160 atmospheres and at a temperature of 300 degrees Celsius. The safety of any nuclear power plant directly depends on its reliable and uninterrupted operation. GTsN casing is made of special steel. The weight of the equipment exceeds 31 tonnes, its height is 3.5 metres and width more than 3 metres. Each reactor requires four such casings.
The agreement for construction of Tianwan 7&8 was signed by Russia and China in 2018 and commissioning is scheduled for 2026-2027. Construction of units 7&8, equipped with VVER-1200 reactors began in May 2021. Units 1-4, with VVER-1000 reactors commissioned between 2007 to 2018 are already in operation. Units 5&6 with Chinese ACPR-1000s were commissioned in 2020 and 2021. Tianwan NPP is owned and operated by the Jiangsu Nuclear Power Corporation, whose shareholders are CNNC (50%), China Power Investment Corporation (30%) and Jiangsu Guoxin Group (20%).
