This paper analyzes the role of nuclear power of China's energy structure and industry system. Comparing with other renewable energy the nuclear power chain has very low greenhouse gas emission, so it will play mo...This paper analyzes the role of nuclear power of China's energy structure and industry system. Comparing with other renewable energy the nuclear power chain has very low greenhouse gas emission, so it will play more important role in China's low-carbon economy. The paper also discussed the necessity of nuclear power development to achieve emission reduction, energy structure adjustment, nuclear power safety,environmental protection, enhancement of nuclear power technology, nuclear waste treatment, and disposal, as well as nuclear power plant decommissioning. Based on the safety record and situation of the existing power plants in China, the current status of the development of world nuclear power technology, and the features of the independently designed advanced power plants in China, this paper aims to demonstrate the safety of nuclear power. A nuclear power plant will not cause harm either to the environment and nor to the public according to the real data of radioactivity release, which are obtained from an operational nuclear plant. The development of nuclear power technology can enhance the safety of nuclear power. Further, this paper discusses issues related to the nuclear fuel cycle, the treatment, and disposal strategies of nuclear waste, and the decommissioning of a nuclear power plant, all of which are issues of public concern.展开更多
Thermal cracking is broadly observed in rock engineering.A finite element numerical model which considers the heterogeneity of rock materials and the damage evolution process was used to simulate the thermal cracking ...Thermal cracking is broadly observed in rock engineering.A finite element numerical model which considers the heterogeneity of rock materials and the damage evolution process was used to simulate the thermal cracking behavior of square rock samples heated from the central borehole.The thermal and mechanical behaviors of two cases,i.e.,the case with large size but low heating rate and the case with small size but high heating rate were compared to study the crack initiation location in the models with different model sizes and heating rates.The simulated stress and temperature fields,as well as the failure pattern,were in good agreement with the experimental observations.The temperature and thermal stress distribution during the heating process in both cases indicated that high tensile stress was concentrated around the thermal gradient front,which resulted in the cracks initiating at the location with a certain distance away from the borehole.The results show that under the same heating rate,crack initiation location moves outwards with the increment of the model size then remains approximately at one location,which reflects the boundary-effect.Furthermore,the results indicate that the relative crack initiation locations in two cases are nearly the same if the ratio between the heating rate in two cases(Tx/Ty)nearly equal to the square of the inverse ratio of corresponding model side lengths((ay/ax)2).This concept is named the scale-heating rate equivalence effect in this study.It is beneficial for studying thermal cracking of rock both numerically and experimentally since the model size can be significantly decreased.展开更多
文摘This paper analyzes the role of nuclear power of China's energy structure and industry system. Comparing with other renewable energy the nuclear power chain has very low greenhouse gas emission, so it will play more important role in China's low-carbon economy. The paper also discussed the necessity of nuclear power development to achieve emission reduction, energy structure adjustment, nuclear power safety,environmental protection, enhancement of nuclear power technology, nuclear waste treatment, and disposal, as well as nuclear power plant decommissioning. Based on the safety record and situation of the existing power plants in China, the current status of the development of world nuclear power technology, and the features of the independently designed advanced power plants in China, this paper aims to demonstrate the safety of nuclear power. A nuclear power plant will not cause harm either to the environment and nor to the public according to the real data of radioactivity release, which are obtained from an operational nuclear plant. The development of nuclear power technology can enhance the safety of nuclear power. Further, this paper discusses issues related to the nuclear fuel cycle, the treatment, and disposal strategies of nuclear waste, and the decommissioning of a nuclear power plant, all of which are issues of public concern.
基金supported by the National Natural Science Foundation of China(Grant No.51874065)the National Major Scientific Instruments Development Project(Grant No.51627804).
文摘Thermal cracking is broadly observed in rock engineering.A finite element numerical model which considers the heterogeneity of rock materials and the damage evolution process was used to simulate the thermal cracking behavior of square rock samples heated from the central borehole.The thermal and mechanical behaviors of two cases,i.e.,the case with large size but low heating rate and the case with small size but high heating rate were compared to study the crack initiation location in the models with different model sizes and heating rates.The simulated stress and temperature fields,as well as the failure pattern,were in good agreement with the experimental observations.The temperature and thermal stress distribution during the heating process in both cases indicated that high tensile stress was concentrated around the thermal gradient front,which resulted in the cracks initiating at the location with a certain distance away from the borehole.The results show that under the same heating rate,crack initiation location moves outwards with the increment of the model size then remains approximately at one location,which reflects the boundary-effect.Furthermore,the results indicate that the relative crack initiation locations in two cases are nearly the same if the ratio between the heating rate in two cases(Tx/Ty)nearly equal to the square of the inverse ratio of corresponding model side lengths((ay/ax)2).This concept is named the scale-heating rate equivalence effect in this study.It is beneficial for studying thermal cracking of rock both numerically and experimentally since the model size can be significantly decreased.
