Comparative Analysis Of The Safety Of Nuclear Safety Related Concrete Structures In Pressurized Water Reactor Nuclear Power Plant In Chinese And American Code

Nuclear safety-related concrete structures and concrete containments are the most important civil structures in nuclear power plant.To ensure the safe production as well as to prevent large-scale nuclear leakage under extreme design conditions,it deserves a high degree of attention when designing nuclear power plant civil structures.Therefore,according to the demands in the compilation process of the new national standard " Technical Standard for Concrete Structures in nuclear power plant",this paper compares the safe degree of Chinese and American design specifications of the nuclear safety related concrete structures and containment structures.The main contents and conclusions are as follows:(1)Put forward the comprehensive safety factor to compare different specifications.Taking into account differences in test methods and guaranteed rate,convert the material strength.According to the computed results,the concrete strength in American code is higer than that in Chinese code,the specified steel strength in American code is equal to the standard steel strength in Chinese code.(2)Compare the degree of security of the axial tensile,axial compression,flexural,out of plane shear,punching,eccentric compression,local compression,torsion,deeply-bending,as well as bracket and prestressed concrete members in nuclear safety related concrete structures.Studies showed that compared with the American specifications,the local compression,punching,prestressed concrete in axial tensile and flexural have a higher degree of security in Chinese code.Bracket's safe degree is lower in Chinese code when compared with the simplified method in American code,and is of same safe degree when compared with the strut-and-tie method in American code.The safe degree of the other components is very close in the two specifications.(3)Calculate and compare the reliability index of structural members of nuclear safety-related concrete structures in bending,shearing,axial compression,axial tension and eccentric compression under normal operating conditions and accident conditions.In both conditions there are some differences in reliable indicators of different members,but the overall average reliability index is of little differences between the two specifications in both normal and accident conditions.(4)Compare the the non-structural provisions of aseismatic nuclear safety related concrete structures,the results shows that the non-structural requirements of beam,column and node in anti-seismic first class frame in Chinese code is close to the requirements in American code.Especially,in Chinese code,the minimum stirrup reinforcement ratio of beam and the ability to ensure “strong column and weak beam” is higher than that in American code.Most of the other non-structural requirements of seismic frames in other anti-seismic class is lower than the requirements in the American code.(5)Compare the safe degree of specifications for the containment structures in China and America.The results showed that,for the design of normal sections,the compressive stress limit value in American code under factored load is higher than that in the Chinese code,steel stress limit value is of little differences in Chinese and American code;for service load design,the concrete compression stress limit value is higher than the value in American code when primary force acts alone,and is lower than the value when primary and secondary force acts at the same time.As to the inclined section design,the safe degree of radial shear without axial lod,radial shear with axial compressive force,torsion,tangential shear is of little differences between two specifications.The safe degree of radial shear with axial tensile force or prestress is higher in Chinese code than that in American code.Compared with the American code,the safe degree of peripheral shear is lower in Chinese code.