On March 21, 2018, the lifting of the dome of the reactor plant of Fuqing Nuclear Power Unit 6 was completed. Photo courtesy CNNC Group
22.3 MPa: The atmospheric pressure we are exposed to daily is 0.1 MPa, while the primary circuit operating pressure of Fuqing Nuclear Power Unit 5 is 15.5 MPa. According to the design, the primary circuit design pressure is about 17 MPa. But the peak of the cold test is 22.3 MPa, which is equivalent to the weight of 10 fully loaded cars on a large palm area. 
< p class = "image_desc"> Image source: China Nuclear Group Science and Technology Daily WeChat public account May 26 news, at 5:00 on May 13th, Hualong No. 1 world’s first reactor-China Nuclear Group Fuqing Nuclear Power Unit 5 ( Hereinafter referred to as Fuqing Nuclear Power Unit 5) The pressure in the containment plant drops to atmospheric pressure. Under the common attention of all the test participants, the gate to the inner containment was slowly opened, which marked the successful completion of the integrity test of the inner containment of Unit 5 of Fuqing Nuclear Power!
Containment integrity test including containment and strength test is a large-scale comprehensive test before machine assembly, which aims to verify the third course of Hualong No. 1 in the world ’s first pile The integrity and reliability of the safety barrier. The test lasted 9 days, the safety and quality of the test process were controllable and unbiased, and the containment leak rate verification test was carried out for the first time and qualified once.
On May 23, Gu Jun, deputy to the National People ’s Congress, general manager of China National Nuclear Corporation, and deputy secretary of the party group revealed in an interview with the media that Hualong No. 1 The No. 5 generating unit of Duifing Nuclear Power Plant is expected to be put into operation before the end of this year.
After optimization, the construction difficulty doubled
After optimization, the construction difficulty doubled
In December 2016, Fuqing Nuclear Power Unit 5 began the installation of stainless steel pool.
For the nuclear power plant, the pool is of great significance. It undertakes the functions of waste heat extraction, emergency cooling, and radiation protection of the nuclear power unit.
However, unlike one of the most common reactor types in domestic nuclear power plants-the M310 reactor type, Hualong No. 1 has the original reactor cavity pool and stainless steel pool in the fuel plant in the M310 reactor type On the basis of the two large ponds, four new ponds were added: internal displacement feed water tank, auxiliary feed water tank, passive heat export pool and passive reactor cavity injection tank. Among them, the reactor cavity pool has a larger volume than the M310 reactor type, and the weight of the reactor cavity gate is more than twice that of the M310 reactor type. In addition, Hualong No. 1 has also set up a waste liquid collection system and a medium and low radioactive waste liquid treatment and storage facility in the nuclear island plant.
These optimizations mean that the workload of the stainless steel pool of Unit 5 of Fuqing Nuclear Power has suddenly doubled, greatly increasing the construction period and difficulty.
In order to ensure the orderly construction of the stainless steel pool of Unit 5 of Fuqing Nuclear Power, under the deployment of China Nuclear Power Engineering Co., Ltd., Fuqing Nuclear Power Project Department organized the construction of China ’s nuclear industry Co., Ltd. and the participating units set up a special team for stainless steel cladding construction to coordinate and coordinate the construction of stainless steel pools. Due to the complex design and huge engineering volume, it took 3 years and 4 months before and after the manufacture and inspection of the pool.
The welding volume of the Hualong No. 1 single-unit stainless steel pool is about 6 times that of the M310 stack, and the amount of flaw detection is about 15 times that of the M310 stack. The stainless steel pool sealing test is to verify the quality of the welds of all pools and the tightness of the pool. The total weld length of the six pools is about 13,000 meters, and the number of flaw detection films is about 28,000. If the average number of film shots per day is 40, the flaw detection process lasts about 700 days.
“In the final sprint stage, we encountered a new coronary pneumonia epidemic. On the premise of doing a good job in the prevention and control of the epidemic, the construction special team actively promoted the resumption of production, ensuring Fuqing Nuclear Power The successful completion of the sealing test of the stainless steel pool of Unit 5 has laid the foundation for the important loading node of Unit 5 of Fuqing Nuclear Power. “Ni Haitao, the relevant person in charge of the project department of China Nuclear Power Corporation Nuclear Power Engineering Corporation
Various tests to ensure safety
Various tests to ensure safety
If the power station is likened to a huge charging treasure, then Hualong No. 1 is a huge nuclear fuel charging treasure -“Nuclear Power Po”. When considering a nuclear power plant, one of the most important indicators is safety and reliability.
Xinhua News Agency reporter Wei Peiquan The construction of a nuclear power plant has gone through several stages of R & D and design, civil construction, equipment installation and commissioning.
The commissioning phase includes cold test, hot test, charging, grid connection and other nodes.
On April 27, 2019, the primary circuit hydraulic test of Fuqing Nuclear Power Unit 5 was officially launched, marking the unit ’s plan to start a cold test 50 days in advance, from the installation stage Fully transferred to the debugging stage.
The cold test is a large-scale comprehensive special commissioning test for nuclear power plants. It is considered as a “warm-up” before the hot test. The main purpose is to verify the primary circuit systems and equipment and their auxiliary pipelines The pressure bearing capacity and leakage rate under high pressure, and the related tests of the main system and auxiliary system under each pressure platform are the first comprehensive “physical examination” of the entire reactor performance.
It is also considered to be the first step in testing this “nuclear power treasure”, which can verify the integrity of each system and whether it can maintain normal pressure under the design basis . Whether the first pile can be pushed forward as scheduled, the “Physical Examination” report is critical.
Stress is one of the first indicators to be evaluated in the cold test. The atmospheric pressure we are exposed to daily is 0.1 MPa, while the primary circuit operating pressure of Fuqing Nuclear Power Unit 5 is 15.5 MPa. According to the design, the primary circuit design pressure is about 17 MPa. But the peak of the cold test is megapascals, which is equivalent to the weight of 10 fully loaded cars on a large palm area.
On April 28, 2019, the primary circuit hydraulic pressure test of Fuqing Nuclear Power Unit 5 was successful. This marks that Hualong No. 1 is the first in the world to withstand the “high pressure” and successfully passed a “big test” to check the performance of the unit, and a hot test can be carried out.
The hot test is the abbreviation of the hot state performance test. Compared with the cold test temperature of 35-70 degrees Celsius, the hot test temperature is as high as 300 degrees Celsius. During the hot test, the staff will try to simulate the actual operating conditions of the nuclear power plant as much as possible to verify whether the system performance is consistent with the design requirements, and further verify the reliability of the nuclear power plant, including whether the system parameters meet the design requirements. In addition,To verify the reliability of the instrument and equipment at high temperature, check whether the measurement parameters such as temperature, pressure, flow, vibration, and gap meet the design value requirements.
For this reason, compared with the cold test, the hot test is a relatively long process. It is not a single test, but the sum of a series of tests.
Depending on the unit, the heat test can range from tens of days to more than a few months. During the thermal test, the operating rules of the nuclear power plant will be comprehensively verified, the functions of the nuclear power plant will be fully tested, and the operation team of the nuclear power plant will also be trained.
On March 2, the thermal test of Fuqing Nuclear Power Unit 5 was basically completed, which laid a solid foundation for the follow-up machine assembly materials, grid-connected power generation and other work.
Collaborate on design work in different places
Collaborate on design work in different places
After the hot test, according to the plan, the No. 5 unit of Fuqing Nuclear Power Plant will be charged for the first time. The first charge is the beginning of the operation of a nuclear power plant and is of great significance.
Before the first charge, Fuqing Nuclear Power Company, which is responsible for the operation of Fuqing Nuclear Power Unit 5, needs to submit the “Application for the First Loading of Fuqing Nuclear Power Plant Unit 5” to the National Nuclear Safety Administration .
According to China ’s Civil Nuclear Facilities Safety Supervision and Management Regulations and their implementation rules and safety regulations and guidelines for nuclear power plants, the National Nuclear Safety Administration is reviewing the application documents submitted by the company , And after on-site inspection, if it is considered that the unit construction meets the basic requirements of nuclear safety, there are sufficient safety measures to ensure that its operation will not cause excessive radiation hazards to the plant area, the public and the environment, meet the basic requirements of nuclear safety regulations, and have the first loading conditions , The first loading approval will be issued for the unit.
After the loading is completed, Fuqing Nuclear Power Unit 5 will usher in formal grid-connected power generation and put into operation.
Since the start of work on May 7, 2015, Fuqing Nuclear Power Unit 5 has progressed smoothly, and construction according to the planned progress has become an important label.
“Hualong No. 1 is a complex system engineering and an innovation process from scratch.” Xing Ji, chief designer of China Nuclear Group Hualong No. 1 said, Fuqing Nuclear Power One of the key issues of Unit 5 is to complete the construction drawing design of the first pile project on schedule.
By continuing to promote “Internet +”, CNNC Group has combined the design of nuclear power, application software integration with Internet and other technologies, and established a comprehensive remote collaborative design platform. Connect and use various terminal devices to carry out collaborative design work in different places on the same platform. The number of collaborative design platform terminals reaches 500, and can be expanded as needed.
On this platform, nearly a thousand Hualong No. 1 field engineers and designers realized the timely communication and sharing of information, accelerated the transfer of design data, and reduced the design exchange Process, effectively improving design efficiency. 
Xinhua News Agency reporter Wei Peiquan While carrying out the design work, CNNC took full advantage of the design information platform ’s efficient and convenient features and aggregated technical problems encountered in the construction of the demonstration project in time to form big data in the design field , Not only feedback to equipment manufacturers and engineering construction parties, but also passed to subsequent nuclear power projects.
“This has laid the technical foundation for the standardized design and batch construction of the Hualong No. 1 nuclear power project and improved the economics of construction and operation.” Xing Ji said.
(Originally titled “Hualong 1 first reactor put into production at the end of the year, China’s nuclear power submersible” Dragon “vacates”)