China's First Large Commercial Nuclear Power Plant Containment Capacity Is 15 Times That Of Fukushima.

Japan Fukushima nuclear power plant Mainland China's nuclear power plants have also been concerned after the nuclear leak. Recently, the reporter came to Dapeng Peninsula, located in Longgang District of Shenzhen City, Guangdong Province, and visited the Dayawan nuclear power base, which has been completed and running for 17 years.

The Dayawan nuclear power station, which is named after the Dayawan coast, actually includes three nuclear power stations, namely, the Dayawan nuclear power station, which was launched in 1987, and was put into operation in 1994, the first phase of the Lingao nuclear power plant which was launched in 1997 and the commercial operation in 2003, and the No. two unit of Lingao nuclear power plant, which was put into operation in 2005 and was put into operation in 2010.

The Dayawan nuclear power plant and Lingao nuclear power station jointly form a large nuclear power base, which is often referred to as the Dayawan nuclear power base. The installed capacity of Dayawan nuclear power base increased progressively from the initial 1 million 968 thousand kilowatts to 3 million 948 thousand kilowatts in 2003, and then to 5 million 28 thousand kilowatts in 2010. After the commissioning of unit 2 of Lingao Nuclear Power Plant Phase Two this year, the installed capacity will reach 6 million 100 thousand kilowatts.

Dayawan nuclear power station is the epitome of China's nuclear power development history. The Dayawan nuclear power plant is the first million kilowatt class large commercial nuclear power plant built in mainland China. From the introduction of foreign advanced technology to the "introduction, digestion, absorption and re innovation", China's improved pressurized water reactor nuclear power technology with its own brand has been formed. According to the international advanced standards, adhering to the policy of "safety first, quality first", adhering to conservative decision-making and adopting proven mature technology has been the key to the development of Dayawan nuclear power base. In May 13, 2006, the Dayawan nuclear power plant unit 1 completed its first 10 year overhaul. It became the first nuclear power plant in China to run all nuclear power plants during the design period except for decommissioning.

At present, the Dayawan nuclear power base has become the cradle of China's nuclear power, and is an important base for R & D, experience accumulation and personnel training in China. The nuclear power construction team from here has undertaken the construction of Yangjiang nuclear power station, Taishan nuclear power plant phase I, Hongyanhe Nuclear Power Station and Fangchenggang nuclear power station. {page_break}

　 The past and present of Dayawan nuclear power station construction

The Dayawan nuclear power plant is China's largest Sino foreign joint venture project in the initial stage of reform and opening up. After 17 years of commercial operation, the annual power generation capacity has reached 15 billion kilowatt hours. 7 of the output power is exported to Hongkong, which accounts for about 1/4 of the total electricity consumption in Hongkong. One household in every 4 households in Hongkong comes from Dayawan.

Even so, in the course of the preparatory process of the year, the Hongkong community paid great attention to it.

Dayawan is located on the coast of Dayawan, 7 kilometers east of Dapeng, Shenzhen, about 52 km from the center of Shenzhen and about 54 km from Tsim Sha Tsui, Hongkong. Shortly after China decided to build a nuclear power plant in Dayawan, Shenzhen, in April 1986, the Soviet Union had an accident of the Chernobyl nuclear power plant, which shocked the whole world. For a time, people's confidence in the safety of nuclear power plants dropped to the bottom. Some Hongkong citizens and social organizations have launched protests against the signing campaign. The sound of "stop building" and "slow build" the Dayawan nuclear power plant has been heard. After hearing this news, comrade Xiaoping firmly put forward that after careful consideration, the central leadership has not changed or built the Dayawan nuclear power station, and the central government has fully paid attention to the safety of nuclear power plants.

The location of nuclear power plants has been fully considered. According to Li Zhongcheng, an expert in the national energy and nuclear power engineering research and development center, the site of the Dayawan nuclear power base is a nuclear power plant site selected from more than 10 selected sites in the coastal area of Guangdong. It is located in the southeast coastal area of the Eurasian plate, far away from the North South structural belt with strong structural deformation and the subduction zone of the Philippines Sea plate. There is no fracture zone near the site, the crust is safe and stable, and no more than 5 magnitude earthquakes have occurred in history.

The formation of tsunamis is usually caused by a deep-sea earthquake with a scale of more than 6.5 on the Richter scale, and the depth of the ocean reaches 1000 meters. The depth of the coastal waters in Guangdong is relatively shallow, and the depth of the sea in Dayawan is only 20~30 meters, so it is difficult to form a large-scale tsunami. At the seaside nuclear power station, there are breakwaters in design. In addition, a breakwater with a height of 16 meters and a length of 556 meters is built on the periphery of the nuclear power plant. The irregular concrete blocks ranging from 14 tons to 40 tons are stacked under the embankment. Once the tsunami hits, the breakwater will play a role of breaking waves.

It is reported that the largest natural disaster risk in China's coastal nuclear power plant is actually a super typhoon. The Dayawan nuclear power station is located in areas where thermal typhoons frequently occur. The design base flood control level is the astronomical high tide rate exceeding 10%, the maximum storm surge and the sea level rise.

In the process of building the whole project, the builders are filled with a strong sense of mission and responsibility, a firm belief that only succeeds, no failures, and great achievements. Because of this, thousands of builders at home and abroad joined together and formed a tremendous force. Although there are many construction teams and many interfaces between the construction teams on the construction site of the Dayawan project, during the 8 years of construction, we all cooperate with each other sincerely. There are few wrangling and prevarication. There are no common engineering headquarters in Dayawan, but all work is carried out in an orderly way, creating a model for international cooperation.

Dayawan project is an international project. In order to build it into a world-class project, Dayawan began to adopt the international common management mode. Its core lies in strict scientific management, strictly carrying out the work according to the rules, and taking the textual basis and written records as working evidence. To monitor the safety of the Dayawan nuclear power station, Hongkong also has a monitoring and warning system. The Hongkong Observatory has 10 radiation monitoring stations to monitor the level of environmental gamma radiation. If the reading exceeds the preset level, the alarm will be issued. {page_break}

　　 Containment capacity It's 15 times more than Fukushima.

According to Pu Jilong, an expert of the national nuclear power special committee, unlike the Fukushima nuclear power plant using old single stage circulating boiling water reactor technology, the Dayawan nuclear power plant uses pressurized water reactor technology.

Fukushima nuclear power plant uses cooling water to directly introduce seawater to cool the primary loop. The boiling water reactor does not have a steam generator and directly uses steam generated from boiling water to promote the steam turbine. It belongs to the early nuclear power technology built in the late 1960s and early 1970s.

Dayawan has fully absorbed the experience of the Three Mile Island nuclear power plant accident in 1979 and the experience of the former Soviet Union's Chernobyl nuclear power plant accident in 1986. It has been greatly improved in technology, and has the characteristics of high security, advanced technology and reliable maturity. It belongs to the more advanced and mature nuclear power plant built after 1990s. At present, more than 70 similar units have been built in the world, and the operation experience of more than 1000 types of nuclear power units has been accumulated.

Pu Jilong said that Fukushima nuclear power plant used 40 years ago technology, reactor containment space is relatively small, only about 3400 cubic meters of space, in the case of severe accidents, the process of boosting is faster, prone to hydrogen explosions. The containment of the Dayawan nuclear power plant consists of a reinforced concrete cylinder with 49000 cubic meters of space. It can effectively reduce and dilute the hydrogen concentration and delay the containment boost time. At the same time, the hydrogen elimination system is installed in the containment. Dozens of passive hydrogen combiner which can deal with the risk of hydrogen can resolve the risk of hydrogen explosion caused by hydrogen accumulation in the containment under severe accidents.

Aiming at the accident of core meltdown, Naka Hiro's nuclear power station has set up multiple safety barriers and a number of safety systems specially designed for accidents. The safety system adopts redundancy design, that is, a component failure does not affect the safety function. Even if all the power inside and outside the factory is lost, steam supplied by the two loop can be driven through the core waste heat to drive the nuclear safety related steam feed water pump to the steam generator. At the same time, the two loop has an air discharge system. After the power failure, the heat can be discharged into the atmosphere through the natural circulation cooling core, so that the temperature and pressure in the reactor pressure vessel will continue to rise. In addition, the Dayawan nuclear power station has two emergency diesel engines, each with fifth diesel engines for stand-by.

The Dayawan nuclear power plant is also equipped with sand filter. Under extreme conditions, if the containment pressure exceeds the design value, the sand filter can discharge the gas in the containment to the atmosphere. The sand filter can hold most of the radioactive nuclides in the gas, so that the radioactive substances in the primary loop can not be directly out of control and released to the environment.

That is to say, the Dayawan nuclear power plant reactor has at least three protective barriers: first, nuclear fuel pellets and cladding, effectively preventing radioactive substances from escaping; second, 20 centimeters thick steel pressure shells will seal the primary loop system; third, containment capacity of 49000 square meters, 15 times the Fukushima Daiichi nuclear power station. {page_break}

　 The new site of nuclear power plant will be re screened.

Reporters in Dayawan nuclear power station interview, every moment can feel the safety culture of nuclear power in Dayawan. According to reports, in September 1987, shortly after the start of the Dayawan nuclear power plant, quality inspectors found some steel bars on the nuclear island raft foundation. In order to ensure the quality of the project, the Dayawan nuclear power plant has been rectified for one month with a cost of 1 million US dollars per day.

After putting into commercial operation, it is also strengthened the safety consciousness. In February 1995, when the reactor control rod drop rod test of unit 1 of Dayawan nuclear power plant was conducted, the staff found that a few control rods drop time compared with the design standard. Although the test results were within the margin of safety and did not affect the operation of the unit, the Dayawan nuclear power plant still decisively stopped the unit and opened the reactor pressure vessel for 5 times. The cause of the deviation was thoroughly identified and properly improved before starting the unit operation. The incident took 5 months to deal with, although it has paid enormous economic costs, but in return for the good reputation of Dayawan nuclear power station.

　　 gnps Its reputation in the world is very high. Since the commissioning of the unit, it has been maintaining safe and stable operation. Since 1999, the Dayawan nuclear power plant has won the first prize in 21 entries in the 64 international similar unit's safety performance challenge.

After the strong earthquake and tsunami triggered the Fukushima nuclear power plant accident, in March 13th, Dayawan's central Guangdong Nuclear Power Group held an emergency meeting in a timely manner to deploy safety assessments for the construction and operation of the nuclear power station. In March 16th, the State Council held a standing meeting to make important arrangements for China's nuclear power safety work. After the spirit of the State Council executive meeting reached the group, the central Guangdong Nuclear Power Group immediately implemented the spirit of the meeting. The general manager's department immediately made the deployment. At present, 6 inspection teams have been set up to carry out the nuclear power safety inspection of the group under construction and operation of the nuclear power station.

For the running Dayawan nuclear power station and Lingao nuclear power station, the contents of this inspection are mainly the safety situation of the power station under the influence of extreme weather such as super typhoon, earthquake, storm surge (tsunami), safety condition of the unit, emergency system and exercise, fire protection system, radiation protection system and equipment aging management.

For the construction of nuclear power plants, the main contents of the inspection are the unit's aseismic design standard, the safety status of the plant, the possibility of extreme natural disasters near the site, and the effectiveness evaluation of the new project's emergency system. For the new site of the nuclear power plant, we shall organize safety assessments for all new nuclear power plant sites and re screen the site.