The State Nuclear Power Technology Corporation (SNPTC), which is responsible for the development of third-generation nuclear power technology in China, has completed the preliminary designs
<正>The disposal of spent nuclear fuel is a long-standing issue in nuclear technology.Mainly,UO_2 and metallic U arc used as a fuel in nuclear reactors.Spent nuclear fuel contains fission products and transurani...<正>The disposal of spent nuclear fuel is a long-standing issue in nuclear technology.Mainly,UO_2 and metallic U arc used as a fuel in nuclear reactors.Spent nuclear fuel contains fission products and transuranium elements,which would remain radioactive for 10~4 to 10~8 years.In this brief communication,essential concepts and engineering elements related to high-level nuclear waste disposal are described.Conceptual design models are described and discussed considering the long-time scale activity of spent nuclear fuel or high level waste.Notions of physical and chemical barriers to contain nuclear waste are highiightened.Concerns regarding integrity,self-irradiation induced decomposition and thermal effects of decay heat on the spent nuclear fuel are also discussed.The question of retrievability of spent nuclear fuel after disposal is considered.展开更多
The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and...The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.展开更多
The fast growth in the size and difficulty of nuclear power plant in the 1970s produced an interest in smaller, modest designs that are intrinsically safe over the usage of design features. With the development of nuc...The fast growth in the size and difficulty of nuclear power plant in the 1970s produced an interest in smaller, modest designs that are intrinsically safe over the usage of design features. With the development of nuclear technology, there is the need for revolution in the Maritime sector, especially the advance marine propulsion. In current years, numerous reactor manufacturers are dynamically improving small modular reactor designs with even superior use of safety features. Several designs integrate the ultimate in greater safety. They totally remove specific accident initiators from the design. Other design features benefit to reduce different types of accident or help to mitigate the accident’s consequences. Although some safety features are mutual to maximum SMR designs, irrespective of the coolant technology, other features are specific to liquid-metal cooled, water, gas, or SMR designs. Results: There have been more reactor concepts investigated in the marine propulsion area by different assemblies and research laboratories than in the power generation field, and much can be learned from their experience for land applications. The extensive use of safety features in SMRs potential to make these power plants extremely vigorous, protecting both the public and the investor. Conclusion: For these two considerations, it is recognized that a nuclear reactor is the ideal engine for naval advanced propulsion. The paper will present the work to analyze the concept design of SMRs and design a modular vessel consisting of a propulsion module.展开更多
Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety impl...Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety implications of the near-fault effect on nuclear power plant facilities designed according to the Chinese code. To this end, a set of near- fault ground motions at rock sites with typical forward-directivity effect is examined with special emphasis on several key parameters and response spectra. Spectral comparison of the selected records with the Chinese and other code design spectra was conducted. The bi-normalized response spectra in terms of different comer periods are utilized to derive nuclear design spectra. It is concluded that nuclear design spectra on rock sites derived from typical rupture directivity records are significantly influenced both by the earthquake magnitude and the rupture distance. The nuclear design spectra specified in the code needs to be adjusted to reflect the near-fault directivity effect of large earthquakes.展开更多
开发具有优异综合性能的核反应堆结构材料是核能发展的基础,并且是长期以来制约核能推广的难点之一。多主元合金(multiprincipal element alloys,MEAs)因具有良好的抗辐照性能、力学性能而被认为是先进反应堆结构材料的候选材料,为新型...开发具有优异综合性能的核反应堆结构材料是核能发展的基础,并且是长期以来制约核能推广的难点之一。多主元合金(multiprincipal element alloys,MEAs)因具有良好的抗辐照性能、力学性能而被认为是先进反应堆结构材料的候选材料,为新型抗辐照材料的设计开辟了广阔空间。近年来,有关多主元合金在辐照损伤方面的研究多试图揭示多主元合金一些因素和特性对辐照过程中缺陷形成与演变的影响。例如:主元种类和数目、主元浓度、晶格畸变、化学短程序等。尽管现有的一些研究结果表明以上因素可以提高多主元合金抗辐照损伤能力,但是在不同辐照条件下,以上因素对多主元合金中缺陷形成和演变的影响机制存在较大差异,难以得出普适性的结论。本文围绕FCC和BCC系两类多主元合金的辐照肿胀、氦泡形成、辐照诱导元素偏析和相变、辐照硬化四方面内容,综述了近年来多主元合金在辐照损伤方面的研究进展,总结了多主元合金提高抗辐照性能的作用机制,并在此基础上对核电结构用多主元合金的未来研究方向做出了展望,包括短程序调控、高熵陶瓷、增材制造、高通量结合机器学习加速材料开发等。最后指出必须从合金成分设计的角度出发,基于材料服役的实际环境来设计新型抗辐照多主元合金。展开更多
Safety systems, built on state-of-the-art technology, are essential for achieving acceptable levels of plant safety to minimize hazards to the reactor and the general public. The second shutdown system(SSS) as an engi...Safety systems, built on state-of-the-art technology, are essential for achieving acceptable levels of plant safety to minimize hazards to the reactor and the general public. The second shutdown system(SSS) as an engineered safety feature and a part of the reactor protection system(RPS) is a means for rapidly shutting down a nuclear reactor, keeping it in a subcritical state and serving as a backup to the first shutdown system(FSS). In this research, one SSS with two types of optimum chamber designs is proposed that take into account the main current characteristic features of the Tehran research reactor with improvements over earlier designs. They are based on a liquid neutron absorber injection that is preferably different, diverse, and independent from the FSS based on the rod drop mechanism. The major design characteristics of this SSS with two different chambers were investigated using MCNPX 2.6.0 code. The performed calculations showed that the designed SSS is a reliable shutdown system, assuring an appropriate shutdown margin and injection time, with no significant effects on the effective delayed neutron fraction while causing minimal variations to the core structure. Further, the reasonable financial cost and the prolongation of the operation cycle are additional advantages of this design.展开更多
In order to realize rapid response to performance-driven design for nuclear valve products, a rapid design platform is constructed by combining the structural features with the multi-characteristic optimization requir...In order to realize rapid response to performance-driven design for nuclear valve products, a rapid design platform is constructed by combining the structural features with the multi-characteristic optimization requirement, which integrates parametric design, multi-characteristic simulation, and multidisciplinary design optimization of nuclear power valves together. Through the integration of heterogeneous CAX/MDO software, such as UG, ANSYS and iSIGHT, the analytical efficiency is enhanced by coupling respective and unique advantage of various software systems, and the mutual coordination and information sharing are realized between the heterogeneous systems. The application example shows that the system is convenient operation that improves the automation in design and analysis on nuclear valves. The results can provide a practical and effective development method and technical reference of the integrated design system for valve products.展开更多
Consideration of the dynamic effects of the site and structural parameter uncertainty is required by the standards for nuclear power plants (NPPs) in most countries. The anti-seismic standards provide two basic meth...Consideration of the dynamic effects of the site and structural parameter uncertainty is required by the standards for nuclear power plants (NPPs) in most countries. The anti-seismic standards provide two basic methods to analyze parameter uncertainty. Directly manually dealing with the calculated floor response spectra (FRS) values of deterministic approaches is the first method. The second method is to perform probability statistical analysis of the FRS results on the basis of the Monte Carlo method. The two methods can only reflect the overall effects of the uncertain parameters, and the results cannot be screened for a certain parameter's influence and contribution. In this study, based on the dynamic analyses of the floor response spectra of NPPs, a comprehensive index of the assessed impact for various uncertain parameters is presented and recommended, including the correlation coefficient, the regression slope coefficient and Tornado swing. To compensate for the lack of guidance in the NPP seismic standards, the proposed method can effectively be used to evaluate the contributions of various parameters from the aspects &sensitivity, acuity and statistical swing correlations. Finally, examples are provided to verify the set of indicators from systematic and intuitive perspectives, such as the uncertainty of the impact of the structure parameters and the contribution to the FRS of NPPs. The index is sensitive to different types of parameters, which provides a new technique for evaluating the anti-seismic parameters required for NPPs.展开更多
文摘The State Nuclear Power Technology Corporation (SNPTC), which is responsible for the development of third-generation nuclear power technology in China, has completed the preliminary designs
文摘<正>The disposal of spent nuclear fuel is a long-standing issue in nuclear technology.Mainly,UO_2 and metallic U arc used as a fuel in nuclear reactors.Spent nuclear fuel contains fission products and transuranium elements,which would remain radioactive for 10~4 to 10~8 years.In this brief communication,essential concepts and engineering elements related to high-level nuclear waste disposal are described.Conceptual design models are described and discussed considering the long-time scale activity of spent nuclear fuel or high level waste.Notions of physical and chemical barriers to contain nuclear waste are highiightened.Concerns regarding integrity,self-irradiation induced decomposition and thermal effects of decay heat on the spent nuclear fuel are also discussed.The question of retrievability of spent nuclear fuel after disposal is considered.
基金funded by the Basic Science Research Foundation of IEM(Grant No.2006A02)the National Natural Sciences Foundation of China (90715038)
文摘The main technical backgrounds and requirements are introduced with regard to earthquake ground motion design parameters in several domestic and American standards,codes and guides involved in the seismic analysis and design activities of nuclear power plants in China.Based on the research results from site seismic safety evaluation of domestic nuclear power plant projects in the last years,characteristics and differences of site specific design spectra are analyzed in comparison with standard response spectra,and the suitability of standard response spectra for domestic nuclear power plant projects is discussed.
文摘The fast growth in the size and difficulty of nuclear power plant in the 1970s produced an interest in smaller, modest designs that are intrinsically safe over the usage of design features. With the development of nuclear technology, there is the need for revolution in the Maritime sector, especially the advance marine propulsion. In current years, numerous reactor manufacturers are dynamically improving small modular reactor designs with even superior use of safety features. Several designs integrate the ultimate in greater safety. They totally remove specific accident initiators from the design. Other design features benefit to reduce different types of accident or help to mitigate the accident’s consequences. Although some safety features are mutual to maximum SMR designs, irrespective of the coolant technology, other features are specific to liquid-metal cooled, water, gas, or SMR designs. Results: There have been more reactor concepts investigated in the marine propulsion area by different assemblies and research laboratories than in the power generation field, and much can be learned from their experience for land applications. The extensive use of safety features in SMRs potential to make these power plants extremely vigorous, protecting both the public and the investor. Conclusion: For these two considerations, it is recognized that a nuclear reactor is the ideal engine for naval advanced propulsion. The paper will present the work to analyze the concept design of SMRs and design a modular vessel consisting of a propulsion module.
基金National Natural Science Foundation of China Under Grant No.50808168Ministry of Science and Technology of Weihai Under Grant No.2008087Beijing Natural Science Foundation Under Grant No.8092029
文摘Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety implications of the near-fault effect on nuclear power plant facilities designed according to the Chinese code. To this end, a set of near- fault ground motions at rock sites with typical forward-directivity effect is examined with special emphasis on several key parameters and response spectra. Spectral comparison of the selected records with the Chinese and other code design spectra was conducted. The bi-normalized response spectra in terms of different comer periods are utilized to derive nuclear design spectra. It is concluded that nuclear design spectra on rock sites derived from typical rupture directivity records are significantly influenced both by the earthquake magnitude and the rupture distance. The nuclear design spectra specified in the code needs to be adjusted to reflect the near-fault directivity effect of large earthquakes.
文摘开发具有优异综合性能的核反应堆结构材料是核能发展的基础,并且是长期以来制约核能推广的难点之一。多主元合金(multiprincipal element alloys,MEAs)因具有良好的抗辐照性能、力学性能而被认为是先进反应堆结构材料的候选材料,为新型抗辐照材料的设计开辟了广阔空间。近年来,有关多主元合金在辐照损伤方面的研究多试图揭示多主元合金一些因素和特性对辐照过程中缺陷形成与演变的影响。例如:主元种类和数目、主元浓度、晶格畸变、化学短程序等。尽管现有的一些研究结果表明以上因素可以提高多主元合金抗辐照损伤能力,但是在不同辐照条件下,以上因素对多主元合金中缺陷形成和演变的影响机制存在较大差异,难以得出普适性的结论。本文围绕FCC和BCC系两类多主元合金的辐照肿胀、氦泡形成、辐照诱导元素偏析和相变、辐照硬化四方面内容,综述了近年来多主元合金在辐照损伤方面的研究进展,总结了多主元合金提高抗辐照性能的作用机制,并在此基础上对核电结构用多主元合金的未来研究方向做出了展望,包括短程序调控、高熵陶瓷、增材制造、高通量结合机器学习加速材料开发等。最后指出必须从合金成分设计的角度出发,基于材料服役的实际环境来设计新型抗辐照多主元合金。
文摘Safety systems, built on state-of-the-art technology, are essential for achieving acceptable levels of plant safety to minimize hazards to the reactor and the general public. The second shutdown system(SSS) as an engineered safety feature and a part of the reactor protection system(RPS) is a means for rapidly shutting down a nuclear reactor, keeping it in a subcritical state and serving as a backup to the first shutdown system(FSS). In this research, one SSS with two types of optimum chamber designs is proposed that take into account the main current characteristic features of the Tehran research reactor with improvements over earlier designs. They are based on a liquid neutron absorber injection that is preferably different, diverse, and independent from the FSS based on the rod drop mechanism. The major design characteristics of this SSS with two different chambers were investigated using MCNPX 2.6.0 code. The performed calculations showed that the designed SSS is a reliable shutdown system, assuring an appropriate shutdown margin and injection time, with no significant effects on the effective delayed neutron fraction while causing minimal variations to the core structure. Further, the reasonable financial cost and the prolongation of the operation cycle are additional advantages of this design.
基金Sponsored by International Science & Technology Cooperation Program of China (Grant No.2009DFA71860)Key Project of Chinese Ministry of Education (Grant No.210058)
文摘In order to realize rapid response to performance-driven design for nuclear valve products, a rapid design platform is constructed by combining the structural features with the multi-characteristic optimization requirement, which integrates parametric design, multi-characteristic simulation, and multidisciplinary design optimization of nuclear power valves together. Through the integration of heterogeneous CAX/MDO software, such as UG, ANSYS and iSIGHT, the analytical efficiency is enhanced by coupling respective and unique advantage of various software systems, and the mutual coordination and information sharing are realized between the heterogeneous systems. The application example shows that the system is convenient operation that improves the automation in design and analysis on nuclear valves. The results can provide a practical and effective development method and technical reference of the integrated design system for valve products.
基金the State Key Program of the National Natural Science Fundation of China under Grant No.51138001the Science Fund for Creative Research Groups of the National Natural Science Foundation of China under Grant No.51421064+2 种基金the State Key Laboratory of Coastal and Offshore Engineering Young Scholars Innovation Fund(LY1609)the Fundamental Research Funds for the Central Universities under Grant No.DUT15TD17the Open Research Fund of Hunan Province Key Laboratory of Key Technologies for Water Power Resources Development under Grant No.PKLHD20130
文摘Consideration of the dynamic effects of the site and structural parameter uncertainty is required by the standards for nuclear power plants (NPPs) in most countries. The anti-seismic standards provide two basic methods to analyze parameter uncertainty. Directly manually dealing with the calculated floor response spectra (FRS) values of deterministic approaches is the first method. The second method is to perform probability statistical analysis of the FRS results on the basis of the Monte Carlo method. The two methods can only reflect the overall effects of the uncertain parameters, and the results cannot be screened for a certain parameter's influence and contribution. In this study, based on the dynamic analyses of the floor response spectra of NPPs, a comprehensive index of the assessed impact for various uncertain parameters is presented and recommended, including the correlation coefficient, the regression slope coefficient and Tornado swing. To compensate for the lack of guidance in the NPP seismic standards, the proposed method can effectively be used to evaluate the contributions of various parameters from the aspects &sensitivity, acuity and statistical swing correlations. Finally, examples are provided to verify the set of indicators from systematic and intuitive perspectives, such as the uncertainty of the impact of the structure parameters and the contribution to the FRS of NPPs. The index is sensitive to different types of parameters, which provides a new technique for evaluating the anti-seismic parameters required for NPPs.