1 Introduction
Nuclear safety plays an important role in the national security system, which is an important support for other securities, such as territorial security, national defense security, and economic security. Nuclear safety work has high professional and technical characteristics, and the occurrence of serious nuclear accidents historically is related to a defect or lack of nuclear safety technology
[1]. Therefore, making continuous innovation in science and technology, improving the nuclear safety technology system, boosting the nuclear safety level in essence, and preventing a nuclear accident are important and meaningful for ensuring national defense security, thereby realizing the healthy and ordered development of the nuclear industry, promoting the construction of an ecological civilization, supporting the high-quality development of the economy and society, and satisfying the modern living needs of residents.
Nuclear safety technology is a scientific theory and technical method to ensure nuclear and radiation safety, prevent nuclear accidents, and reduce and relieve the damage caused by nuclear accidents
[2]. Increasing attention has been paid to nuclear safety technology after nuclear accidents occurred at Chernobyl, Three Mile Island, and Fukushima. Compared with powerful nuclear countries, China’s nuclear safety technology started relatively late, and its foundation is weak. Thus, a number of policy documents have been issued, and relevant work in the nuclear safety technology field has been deployed comprehensively in recent years to strive for advanced international levels as soon as possible. China has made significant progress in nuclear safety law and regulation systems, nuclear safety supervision systems, nuclear safety software, equipment independence, and nuclear safety culture construction, which lay a solid foundation for the globalization of the nuclear power.
To continuously improve the level of China’s nuclear safety technology and achieve the long-term goal of becoming a powerful nuclear country, strategic research and top-level design regarding nuclear safety development have been carried out energetically with the support of the “Research on the Development Strategy of China’s Nuclear Science and Technology (Phase II)” project of the Chinese Academy of Engineering, including analysis of the nuclear safety technology development of nuclear powerful countries, research on the macro demand of nuclear safety technology for modernized construction in the current era, summary of achieved accomplishments, refinement of existing problems, and proposals for the key direction and research path. Then, suggestions are proposed to provide a reference for China’s nuclear safety technology development and management.
2 Developing status of nuclear safety technology abroad
2.1 Nuclear safety standard system improved continuously and regulation operated clearly
Safety standards were formulated in the 1970s by the International Atomic Energy Agency (IAEA) and were massively sorted out in the middle of the 1990s. Subsequently, a high-level nuclear safety standards system was formed by continuous updates and improvements. With the rapid development of the nuclear power industry worldwide, the nuclear safety standards formulated by the IAEA have been an important method to ensure that nuclear power development is safe, efficient, and sustainable. The standards have been adopted by many countries, such as the United States and France, which possess the most nuclear power facilities
[3].
Based on the domestic industrial foundation and technical system, an independent nuclear power standards system in line with national conditions was established by the United States and France by consulting the standards system of IAEA. As the nuclear power technologies of the United States and France did not develop simultaneously, their formulating models for nuclear safety standards are different. Independent, complete, and operable nuclear power standards systems were established in the United States and France. With the continuous and intensive development of nuclear safety technology, the relevant nuclear safety standards systems have been updated and improved constantly, which provides a good foundation for the export of nuclear power equipment from the United States and France.
The United States has the advantage of early development in nuclear power technology, and its nuclear standards are the most complete, covering the entire nuclear industry chain. The number of nuclear standards exceeds 1000, and most of them are original
[4]. As an import country of nuclear power technology, France has adopted the efficient development path of “introduction–transformation–re-innovation.” On the basis of the relevant standards systems of the United States, a special standardization organization was established by France fully considering the influence of domestic laws and industrial foundation, which is responsible for the formulation and unified management of nuclear safety systems. Although the centralized management mode weakens the potential of standards to guide the innovation and development of technology to some extent, it provides great convenience for accelerating the application of industrial systems, reducing the qualification requirements of users reasonably, solidifying the standards contents, and forming a high-quality standards system steadily
[4].
2.2 Fundamental research improved and reactor numerical simulation capability enhanced continuously
Nuclear safety analysis software is an important support for the design, construction, and operation of nuclear power plants. Powerful nuclear countries have paid significant attention to the research on nuclear safety analysis software in the process of developing nuclear power technology and have developed nuclear safety analysis software suitable for various scenarios. To verify the effectiveness of nuclear safety analysis software, large-scale integrated performance test platforms have been established (such as the BETHDY test platform of France, ROSA test platform of Japan, and APEX test platform of the University of Oregon in the United States
[5]); these play an important role in the application and promotion of relevant software.
Fundamental research on accident phenomena, mechanisms, and algorithm theory has been significantly enhanced with more intensive studies on nuclear safety analysis software in recent years. By implementing successive projects such as NURESIM, SURISP, and NURESAFE, the European Union has improved the research level of advanced algorithm/modeling and supercomputer platform applications and formed a nuclear safety analysis software system with higher time and space precision with respect to reactor core physics, thermohydraulics, fuel performance, and irradiation performance of materials. In addition, the relevant institutes of the United States have completed the research and development (R&D) of high-precision nuclear safety analysis software with the support of the CASL program and the NEAMS project [6,7]. Benefiting from the accumulation of R&D experience and knowledge achievements in the past decades, the technology state and capacity of the nuclear safety analysis software have tended to be mature, and they play a key role in the design, safe operation, and accident prevention of nuclear power plants.
2.3 Innovation capacity of nuclear safety equipment enhanced continuously and gaining the initiative in the market of advanced-precise-top nuclear safety equipment
Based on the strong industrial base and the advantage of early development in nuclear power technology, the powerful nuclear countries represented by the United States have mastered a series of advanced technologies in R&D, design, production, verification, and maintenance of nuclear safety equipment and formed a complete nuclear safety equipment system by constant accumulation and expansion of independent intellectual property rights and key technologies. Through continuous optimization and improvement, the performance of equipment products has been improved significantly, and the accuracy and reliability have an absolute advantage, which enables these powerful nuclear countries to have the initiative in the market for precision instruments and key equipment. Taking nuclear instruments in a reactor as an example, U.S. and French enterprises have covered various subdivision directions after long-term development. Thermo Fisher has provided more than 650 neutron flux monitors for more than 130 nuclear power reactors in 16 countries or regions, and more than 130 neutron flux monitors for more than 30 research reactors worldwide
[8].
3 Achievements of nuclear safety technology in China
3.1 Good performance in nuclear safety and nearly international advanced level in nuclear safety technology
At present, the overall safety situation of China’s nuclear power is stable, with a good safety record. No nuclear accidents of Class 2 or above have occurred in operating nuclear power units. The main operating performance has maintained an advanced level worldwide, and some components of safety indicators have reached the international leading level. The designed performance indicators of newly built nuclear power units satisfy the latest international nuclear safety standards. The quality of the nuclear power units under construction can be controlled. The potential safety hazards associated with research reactors and nuclear fuel cycle facilities have been eliminated, and safety risks have further decreased. The decommission and waste management of nuclear facilities have been continuously promoted. The utilization and management of nuclear technologies has become more standardized. Notable progress has been made in radiation environmental risk management in the mining and smelting of uranium. The ability to resist extreme natural disasters such as floods and earthquakes and the prevention and relief of serious accidents have been further improved, and emergency preparedness and response have been continuously enhanced
[9].
3.2 Establishment of a standard nuclear safety laws and regulations system in line with international standards and national conditions
China’s policy and law system has been improved continuously, and nuclear safety has been brought into the overall national security system and written into the
National Security Law of the People’s Republic of China. The
Nuclear Safety Law of the People’s Republic of China has been promulgated and implemented, and the legislative deliberation of the
Atomic Energy Law of the People’s Republic of China (Draft for Comments) has been promoted. A white paper on Nuclear Safety in China was published for the first time; it describes the construction route map for the relevant regulations and standards. According to the latest international standards, nuclear safety department regulations have been revised, and the nuclear and radiation safety management system has been improved
[8]. Some key components (such as high-performance detectors and photomultiplier tubes used for the production of radiation detection equipment) depend on imports
[18]. In addition, many domestic manufacturing enterprises have stayed in the imitation stage, so product performance is not advanced. Taking nickel-based welding rods as an example, the performance of domestic rods is similar to that of foreign countries only in terms of chemical composition and mechanical properties, but the welding operation performance is obviously weaker, with issues such as arc instability, poor slag removal ability, and poor current adaptability.
Third, the construction of a quality culture and nuclear safety culture for nuclear safety equipment is insufficient. The construction of a quality assurance system and nuclear safety culture has not kept pace with the breakthrough of new equipment and technology, and as a result, the implementation of process discipline is not strict enough, low-level errors frequently occur, and the overall quality of equipment is not rigorously controlled. Taking the Sanmen nuclear power plant as an example, many quality problems occurred in the manufacturing process of the AP1000 nuclear island main equipment in phase I, which had detrimental effects on the manufacturing period and cost of the equipment
[19].
5 Key directions and development steps of nuclear safety technology in China
5.1 Nuclear safety standards system
By 2025, nuclear safety standards of important areas such as nuclear facility decommission and small reactor management should be improved gradually to form a system, and the quality of standards should be constantly enhanced. An independent, unified, coordinated, and advanced nuclear safety standards system compatible with the development level of nuclear power will be formed.
By 2035, bilateral and multilateral cooperation mechanisms among nuclear power trade countries should be established and continuously promoted. Standardization research and scientific research achievement transformation will be comprehensively launched. The mutual recognition of standards, standards co-construction, and technology exchange and cooperation should be promoted steadily, which can enhance China’s discourse power in the formulation of international nuclear safety standards.
By 2050, the nuclear safety standards system should reach the world-leading level and ensure the safe and sustainable development of nuclear power both in China and abroad.
5.2 Independent software for nuclear safety analysis
By 2025, a national-level laboratory for nuclear safety analysis software should be established based on the major demands of nuclear safety, and research on nuclear safety software R&D strategy and policy should be carried out. Breakthroughs in basic research such as phenomena, mechanisms, and algorithm theories should be achieved by concentrating the advantages of scientific research institutions, universities, and enterprises, which will support the independence of nuclear safety analysis software in key directions. Independent software should be demonstrated and applied in various nuclear power enterprises and research institutions, initially achieving the development of test–feedback–improvement and promoting the globalization of domestic nuclear power.
By 2035, independent nuclear safety analysis software should be realized completely, and the level should meet or partially exceed that of foreign nuclear safety analysis software in key directions. The capability of the experimental verification platform should be continuously improved, and a part of the key platforms should gain international recognition.
By 2050, independent nuclear safety software should be extensively applied and verified in engineering, which should reach the world-leading level and be applied widely in the international market.
5.3 Key nuclear safety equipment
By 2025, the long-term sustainable cooperation mode between domestic nuclear power owners (including nuclear facility operation departments) and suppliers should be formed. On the premise of nuclear power safety operations, domestic equipment should gradually replace foreign equipment.
By 2035, nuclear power equipment enterprises should cooperate with nuclear power owners to maintain high-quality development of domestic equipment, and a stable and efficient nuclear power equipment supply chain should be formed. The problems should be found and solved continually by an empirical feedback system, and R&D ability should be accumulated. The market competitiveness of domestic suppliers should be increased, and they should be encouraged to participate in international market competition and cooperation. The cost of nuclear power construction should be reduced significantly, and domestic nuclear power equipment should be recognized by the international market.
By 2050, key nuclear safety equipment, parts, and materials should meet or partially exceed the international leading level. The cost of nuclear power construction should be further reduced, and domestic nuclear power equipment should occupy a large share of the international market.
6 Countermeasures and suggestions
6.1 Improvement of nuclear safety standards system
In view of the current lack of nuclear safety standards in some fields and a lack of independent and unified systems, the following suggestions are provided. The relevant supporting documents of the Nuclear Safety Law of the People’s Republic of China should be formulated as soon as possible, which can provide the top-level basis for the construction of nuclear safety governance systems. The top-level design of nuclear safety system construction should be given sufficient attention, and the relationship between power and responsibility of the relevant administrative departments should be clarified to outline the division of responsibility. The overall framework system, basic connotation, and development roadmap of nuclear safety technology should be formulated. Basic research on nuclear safety standards should be reinforced. In the process of research and formulation of standards, quantitative indicators should be defined to improve operability.
6.2 Coordinating resources and tackling key problems to enhance the development of independent nuclear safety software with high quality
To solve the problems of imperfect sharing mechanisms, weak basic research, and insufficient verification and confirmation of independent nuclear safety software, there should be unified organization and coordination, systematic and scientific planning demonstration, comprehensive and strict quality assurance standards, scientific and reasonable platform validation, and authoritative and fair confirmation institutions. It is suggested to maintain the unified management of R&D for independent nuclear safety software and coordinate the research sources and factor allocations of the relevant R&D entities to establish a sharing mechanism for the experimental platform and basic data. Basic research on software algorithms, mechanisms, and phenomena should be enhanced, and a solid foundation for the improvement of independent nuclear safety software should be laid. The construction of a quality assurance system for nuclear safety software should be completed, and the demonstration, application, and promotion of independent nuclear safety software should be carried out.
6.3 Paying more attention to the basic research of nuclear power equipment and conducting the quality construction of domestic equipment
In view of the insufficient independence and control of sophisticated equipment, key components, and materials, the following suggestions are provided. Basic research on the processing and manufacturing technology of nuclear-grade equipment, components, and raw materials should be carried out. Based on the institutional advantages, the superiority entities should be arranged to solve the basic, strategic, and bottleneck problems by giving consideration to planning and the market. The problem of equipment independence should be solved precisely and effectively by giving full play to the regulation and leading effects of the market, supplemented by policy guidance and resource support. The quality standard system of nuclear safety equipment should be improved, and the nuclear safety construction of manufacturing enterprises should be enhanced.
PDF
(433KB)
