Recently, the reactor pressure vessel C sealing ring (hereinafter referred to as "C-ring") of PWR nuclear power plant, which was jointly developed by Shougang Beiye Company, Suzhou BMC and China Guangdong Nuclear Power Group (CGNPC) for 10 years, has been appraised by the Expert Review Committee and received unanimous acknowledgement. This marks that Inconel X750 wire and Inconel 600 strip, the key sealing materials for first-class nuclear equipment initiated by Shougang Beiye Company, have completely broken the material monopoly of foreign countries for more than half a century, realized commercial application, helped "C-ring" to achieve full localization, and become another major breakthrough in the localization of nuclear power equipment in China.

A small sealing ring is relevant to the development of China's nuclear power plants. Previously, although our country has developed our own reactor pressure vessels, regulators, steam generators, etc., as the key components of reactor pressure vessels, "C-ring" was still heavily dependent on imports. The main reasons lie in the high requirements for the material quality, strict parts processing technology, and lack in domestic production. In order to thoroughly break the foreign monopoly and remove the potential threat to the sustained safety of nuclear power equipment, Shougang Beiye Company undertakes the localization development project of "C-ring" materials by forming a joint development team with CGNPC and Suzhou BMC. Shougang Beiye has the courage to take on, innovate and finally overcome the difficulties. It has become the "pioneer" and "icebreaker" of the "C-ring" material.

The "C-ring" evaluation was jointly organized by China General Machinery Industry Association and China Machinery Industry Federation. The evaluation committee is led by Ye Qizhen, academician of the Chinese Academy of Engineering, and Huang Bingchen, deputy director of the Nuclear and Radiation Safety Center of the Ministry of Ecological Environment. The project was evaluated by a review committee composed of 16 experts from Nuclear Power Institute of China, CGNPC, and other institutions. Experts of the evaluation committee agreed that "the product has been successfully applied in the first cycle of commercial operation of Yangjiang No. 5 unit after the water pressure test of reactor pressure vessel, the cold and hot state function test of unit and the successful application of the product. The effort proves that the product has mature manufacturing technology, stable performance and reliable quality, and can be popularized in the new construction and operation of nuclear power plants."