1 Subject Content and Application Scope
This standard specifies the methods for stress analysis and seismic analysis of PWR nuclear power plant valve and the criteria for stress assessment to ensure the integrity of valve structure including pressure boundary.
The valve stress analysis rules proposed by this standard are applicable to standard Grades 1, 2 and 3 valves with nominal diameter DN≥ 25mm. The seismic analysis rules are applicable to seismic Categories I valve and also applicable to non-seismic Categories I valves with seismic requirements.
The valve stress analysis rules proposed in this standard are inapplicable to safety valve and pressure relief valve.
2 Normative References
GB/T 16702-1996 Design Rules for Mechanical Components of PWR Nuclear Islands
EJ/T 1022.1-96 PWR Nuclear Power Plant Valve - General Standard for Design and Manufacture
3 Terms
3.1 Operational safety ground motion (SL1)
It is generally the maximum ground motion that the nuclear power plant may suffer from during operation. In case of such ground motion, to make the nuclear power plant run continuously, those necessary facilities that cause no serious danger to public health and safety must maintain their functional capabilities.
3.2 Ultimate safety ground motion (SL2)
It is the maximum credible ground motion that the plant may suffer from; where probability method is adopted, it is the maximum ground motion that the plant may suffer from with the annual exceedance probability not lower than 10-4.
1 Subject Content and Application Scope
2 Normative References
3 Terms
4 General Rules
5 Analysis Rules of Standard Grade 1 Valve
6 Analysis Rules of Standard Grade 2 Valve
7 Analysis Rules of Standard Grade 3 Valve
8 Seismic Analysis of Valve with Protruding Structure
Appendix A Determination of Permissible Stress Intensity and Permissible Stress of Valve Materials (Supplement)
Appendix B Fatigue Curve (Supplement)
Appendix C Wall Thickness Series of Grade 40 Pipes (Supplement)
Additional Explanation:
