What Is a Reactor Vessel?

A reactor vessel refers to a closed vessel in which a nuclear reactor is placed and subjected to its huge operating pressure, also known as a reactor pressure shell.

The role of the reactor pressure vessel is:

1. Loads the active area and all components in the reactor, which has radiation to the reactor core

The material used to make the reactor vessel has good purity, density, composition and performance uniformity, excellent mechanical properties (strength, plasticity, impact toughness, fracture toughness, etc.), metallurgical quality and good corrosion resistance at medium and high temperatures. , Weldability and radiation resistance (low sensitivity to neutron radiation embrittlement), thermal stability, processability, etc. Among them, the material performance requirements of the barrel section facing the active area are the highest.

Internationally, large-scale forging manufacturers of reactor vessel materials mainly include Japan Steel Works (J SW), French Crusoe, and Doosan Heavy Industries of Korea. Among them, J SW leads the world in overall technical level. In 2007, it produced 87 thousand tons of forgings. It has a 600t steel ingot manufacturing capacity and is equipped with two 300t steelmaking cranes and 100t electroslag remelting furnaces. Crusoe has the manufacturing technology of hollow steel ingots, and is the leader in the manufacture of cylindrical forgings. Doosan Heavy Industries & Construction has the largest production capacity in the world. In 2007, it produced 120,000 tons of forgings. ^[2]

At present, the research hotspots of reactor pressure vessels at home and abroad mainly focus on the following aspects.

1. Initiated by the U.S. Department of Energy, under the organization of the 4th Generation Nuclear Energy System International Forum, the 4th generation advanced nuclear energy system is researching and developing in a predetermined direction, among which the reactor pressure vessel material selection, design, and manufacturing as one of the key technologies Etc. has been the focus and focus of research.

2. With the operation time of large-scale nuclear power plants built abroad in the 1960s and 1970s approaching the design life, there is an urgent need for life assessment and extended life analysis of reactor pressure vessels. Institutions such as Nuclear Industry 728 Design Institute and Nuclear Power Design Institute [37] have carried out work in this regard and have achieved staged research results. At present, the main problem of domestic reactor pressure vessel materials is the localization of material manufacturing, especially the localization of smelting and machining of large castings and forgings. Among them, China First Heavy Machinery Group has implemented the independent transformation projects of cast and forged steel bases and large castings and forgings with the strong support of the state in recent years, aiming at world-class capabilities in terms of capacity.