Nuclear power valve is a special valve for power station. It refers to the valve used in nuclear island N1, conventional island CI, BOP system of power station auxiliary facilities and other thermal power plants in nuclear power plants, which plays the role of cutting off or connecting the pipeline medium. From the safety level, it is divided into nuclear safety level I, II, III and non-nuclear level. Among them, nuclear safety level I has higher requirements. Nuclear power valves are the most widely used medium transmission control equipment in nuclear power plants, and are an indispensable and important part of the safe operation of nuclear power plants.
According to statistics, there are currently 447 nuclear power units in operation around the world, with a total installed capacity of 380 million KW, accounting for about 16.2% of the world’s total power generation. There are 17 countries with installed nuclear power plants that account for more than 25% of their total electricity generation. Among them, France accounted for 77%, South Korea accounted for 38%, Japan accounted for 36%, and the United Kingdom accounted for 28%. The United States also reached 20%. Among the nuclear power units in operation, more than 50% are pressurized water reactors, followed by heavy water reactors, boiling water reactors, graphite reactors, fast breeder reactors, and high temperature gas-cooled reactors. my country’s earlier application of nuclear power technology is the military industry. In the early 1970s, the Navy’s first pressurized water reactor nuclear-powered submarine was officially put into service. Since 1985, when my country designed and built Qinshan Phase I 300,000 KW nuclear power unit, it has successively built 6 nuclear power plants in Daya Bay Qinshan Phase II, Qinshan Phase III, Ling’ao and Tianwan through independent design and construction and the introduction of foreign technologies. The installed capacity reaches 8.7 million KW. It accounts for 2% of the country’s installed power generation capacity. my country plans to increase the installed nuclear power capacity from the current 8.7 million KW to 40 million KW by 2020, which will account for about 4% of the country’s total installed power capacity. Among the nuclear power plants that have been built, all of them are pressurized water reactors except for the third phase of Qinshan which adopts the Canadian heavy water reactor type. The single-unit power parameter of Tianwan Nuclear Power Plant provided by Russia is 1.06 million KW.
Fast breeder reactors built by China Academy of Atomic Energy, Tsinghua University and other units, advanced reactors, high temperature gas-cooled reactors, etc. are still research and test reactors in China. After gaining experience, they will expand the construction of commercial reactors. It is worth noting that the super-third-generation pressurized water reactor nuclear power units AP600 and AP1000 designed by Westinghouse in the United States have higher operational safety, and their design adopts passive principles such as gravity, convection, condensation, etc. The driving force in the system greatly reduces the dynamic driving force such as electricity, hydraulic and gas. At the same time, the use of valves is reduced by 50%, the amount of pumps is reduced by 35%, the amount of cables is reduced by 80%, the number of equipment required for seismic grades is reduced by 45%, and the life of the power station can reach 60 years (currently 30 to 40 years). But this kind of nuclear power plant has not yet been built and operated in the world. my country is currently conducting research and experimental work on third-generation nuclear power plants.
The number distribution of valves in nuclear power plants takes Daya Bay Nuclear Power Station as an example. The nuclear island portion accounts for 43.5%, the conventional island portion accounts for 45%, and the auxiliary facilities account for 11.5%. There are 13,000 valves of various types used in the nuclear island part. In terms of valve configuration, globe valves account for 33.6%, diaphragm valves account for 26.2%, and ball valves account for 12.8%. These three items account for 72.6% of nuclear island valves. From the perspective of the distribution of safety levels, only 2.3% of nuclear grade I, 52% of nuclear grades II and III, and 45.7% of non-nuclear grades. The investment ratio of nuclear power valves in nuclear power plants accounts for about 1.6% of the construction price of nuclear power plants. Calculated based on the construction price of the two million-KW nuclear power plants in Lingao of US$3.5 billion, the valve investment is US$56 million, equivalent to about 460 million yuan. According to the national nuclear power development plan, by 2020, the total investment in valves in new nuclear power plants will reach more than 7 billion yuan (approximately 10 billion yuan if the price increase factors such as materials are taken into account). The maintenance and replacement costs of nuclear power valves account for about 50% of the total maintenance of nuclear power plants. The total annual maintenance cost of a nuclear power plant with two million kilowatt units will be around 135 million yuan. The cost of valve maintenance and replacement is about 67 million yuan per year. When the installed capacity of the million-kilowatt nuclear power plants operating in my country reaches 20 million KW, the annual maintenance and replacement cost of nuclear power valves will reach 670 million yuan. At present, the valves used in my country’s nuclear power plants, except for some domestic valves used in Qinshan Phase I and Phase II, almost all the valves used in other nuclear islands and conventional islands are imported. This situation and the country’s plan to develop nuclear power by 2020 provide a good development opportunity for China’s valve industry, and it is also a severe test for China’s valve industry.
Comparison of domestic and foreign nuclear power valves
Compared with domestic nuclear power valves, foreign nuclear power valves have a complete range, advanced technology, excellent performance and high reliability. The United States built the world’s first experimental nuclear reactor in 1942, and the former Soviet Union built the world’s first nuclear power plant in 1954. In the development process of nuclear power technology for more than 60 years, only for nuclear power valves, a complete design, experiment, manufacturing and testing system has been formed abroad, and a large amount of experience has been accumulated. The products are mature and the technology is reliable. Western companies such as Westinghouse Company in the United States, Vilan Company in Canada, and Ferratone in France have mastered contemporary advanced nuclear power technology. Vilan’s nuclear power valves have a good supply record in almost 90% of the world’s nuclear power plants. Many important nuclear-grade and non-nuclear-grade valves in nuclear islands and conventional islands in nuclear power plants in the world, such as pilot-operated safety valves, main steam isolation valves, regulating valves, etc. The nuclear power valve technology and market are all adopted by well-known valve companies in developed countries. Monopoly and very expensive.
Major foreign companies producing nuclear power valves 1. Rockwell International Corp. Rockwell International Corp. is headquartered in Pittsburgh, Pennsylvania, USA, with more than 120,000 employees. The company has more than 200 factories and offices and more than 100 affiliates, associates and subsidiaries in more than 30 countries outside the United States. The company consists of four production departments: aerospace, automotive, electronics and general industry. With a wide range of products, a wide range of equipment and components are provided for high-precision engineering. Flow control equipment products in Rockwell International’s General Industrial segment, including valves for utilities, and valves for the oil, gas, and nuclear industries. The company produced the first metal-sealed diaphragm valve for nuclear power plants in 1974. 2. Germany’s Sulzer KSB Company The company was founded in 1871, formerly known as Frankenthal Factory. In January 1972, Switzerland’s Sulzer Company and KSB Company established Sulzer-KSB Company at the original site of the factory. And invested 340,000 marks, specializing in the design and manufacture of nuclear power plant pumps and valves. The factory covers an area of 57,400m2 and has more than 3,000 employees. The company’s main products are globe valves, globe check valves, gate valves, spring safety valves, and diaphragm valves for nuclear reactors. And chemical acid-resistant steel globe valve, gate valve, diaphragm valve, etc. 3. Canadian Velen Engineering Co. (VelenEngineeringco.ltd.) Velen Engineering Co., Ltd. was founded in 1950 and has now developed into a pioneer in the world valve industry. There are ten professional factories and more than 2000 employees. The company has representative offices in 60 countries. In addition to three of the valve manufacturing plants of Weeland Engineering Company, the remaining seven are located in the United Kingdom, the United States, France, Germany, Portugal and South Korea. As a major supplier of nuclear power valves, Weilan Engineering has established a reputation for its excellent quality. The company holds an ASME Nuclear Power Plant “N” license for three of its plants in North America. The company produces a large number of power station valves of various types and parameters, including nuclear power valves. The representative nuclear power valves are the nuclear grade I gate valve DN350, the design pressure is 17.6Mpa, and the maximum working temperature is 350 ℃; the nuclear grade II main steam isolation valve is DN800, 1500 pounds. The company’s nuclear power valves are used in 24 countries around the world. 4. British Haatterley Heaton Company (Haatterley Heaton) Haatterley Heaton Company has 60 years of experience in the production of steel valves, and is also a major supplier of valves for nuclear power plants. For more than 40 years, the company’s highly sophisticated various types of bellows-sealed valves have been widely used in nuclear power plants around the world, as well as on nuclear-powered submarines. 5. Fisher Control Company of the United States Fisher Control Company of the United States is famous for the development and production of control valves. Its pilot control valves, cage control valves, spherical control valves, pressure reducing valves and other various types of control valves are widely used in nuclear power plants in various countries. It is a type of control valve, with stable pressure or flow regulation, low noise, and sensitive actuator action.
The above has shared the relevant knowledge of nuclear power valves, from the basic overview to the comparison of nuclear power valves at home and abroad, I hope to help you.