The rail for polar crane has been installed at unit 3 of China’s Xudabao NPP in Liaoning province, according to China National Nuclear Corporation’s China Nuclear Industry 23 Construction Company Limited. The crane is located under the dome of the containment on the cart, which moves 360 ° along a circular rail over the reactor, which allows transport operations to be carried out anywhere in the central hall of the reactor building. It can be used to install large equipment, such as a reactor vessel and steam generators, as well as during maintenance and transportation of fuel.

Russia and China in 2018 signed agreements for the construction of two VVER-1200 reactors as units 3&4 for Xudabao NPP. Rosatom would design the nuclear island and supply key equipment, as well as providing field supervision. China would provide turbine generators and balance of plant. Construction of unit 3 began in July 2021 and unit 4 in May 2022. The units are expected to be commissioned in 2027-2028.

Meanwhile, the Atommash production site of AEM-Technologies (part of Rosatom’s mechanical engineering division Atomenergomash) has completed hydraulic tests of the reactor pressure vessel (RPV) for Xudabao 3. The tests were carried out in a three-level underground caisson – a special hermetic shaft designed for such work. With the help of a crane with a lifting capacity of 600 tonnes, the support ring was first lowered into the stand, then an 11-meter VVER-1200 reactor vessel was installed on it with an accuracy of 0.5 mm. To create a complete seal, plugs and a cover were used, which were connected to the RPV using 54 pins of the main connector.

During the tests, the product was filled with distilled water, heated to 100 degrees and created a maximum pressure (24.5 MPa) – this is 1.4 times higher than the working pressure. As a result, the equipment confirmed the strength of the base metal and welded joints.

The reactor is a vertical cylindrical vessel with an elliptical bottom, inside which the active zone and internal devices are located. From above, the equipment is hermetically sealed with a lid with drives of mechanisms and control and protection organs installed on it, branch pipes for outputting cables of in-reactor control sensors.


Image: The polar crane rail being lowered into place at Xudabao 3 (courtesy of CNI23)