1 Scope of Seismic Evaluation Test for Nuclear Equipment
In nuclear power plant, all equipment classified as seismic category I shall be carried out with seismic evaluation. The equipment classified as seismic category I include all the fluid pressure system mechanical equipment of safety levels 1, 2 and 3, the safety-level nonpressure mechanical equipment, the electrical equipment of Class 1E as well as a few equipment that are classified as non-safety level ones but will perform some safety functions during earthquake. Moreover, some overhead equipment, like crane and ventilation duct, that do not perform safety function but may drop during earthquake and influence other safety-level equipment also shall be carried out with seismic checking. The equipment classified as seismic category I shall be able to bear SL1 and SL2 loads and also shall be ensured of performing their safety functions during or (and) after the earthquake. These safety functions are:
① Maintaining and ensuring the completeness of the pressure boundary of reactor coolant system;
② Achieving the safe shutdown of reactor and also maintaining it at the safe shutdown state;
③ Exhausting the residual heat in reactor core;
④ Being able to reduce and avoid the release of radioactive substances to the environment and also ensuring not exceeding the specified limit.
See appendix for the examples of equipment classified as seismic category I in pressurized water reactor nuclear power plant.
As for the seismic evaluation of equipment, the analysis method, the test method or the combination of analysis and test methods may be adopted, and additionally experience feedback method may be adopted to reason and demonstrate.
If the analysis is inadequate to reasonably and credibly verify the completeness and performability of the equipment classified as seismic category I, e.g. control rod drive line, pump, valve, relay, electrical equipment and measuring instrument, the test method must be adopted to evaluate.
Generally speaking, as for the motile (realizing safety function through mechanical motion) mechanical equipment and the Class 1E electrical equipment, test method should be adopted in the first time of seismic evaluation. In addition, as for some complicated equipment, it is difficult to reasonably and credibly verify their seismic performance (performability) by analysis and calculation method, or in order to verify their mathematical models, the test method may also be adopted for seismic evaluation.
2 Purpose of Seismic Evaluation
The vibration parameters such as natural vibration frequency, vibration mode and damping, and (or) seismic response of the equipment shall be determined through seismic test so as to assess the rigidity (deformation), strength and displacement of equipment and verify whether the equipment is able to work normally, maintain its completeness and performability and also perform its safety function under the action of seismic load.
1 Scope of Seismic Evaluation Test for Nuclear Equipment
2 Purpose of Seismic Evaluation
3 Requirements for the Vibrostand (or other Shock Excitation Equipment) and Peripheral Equipment Used for Seismic Evaluation
4 Ordering of Equipment Seismic Evaluation Test in the Acceptable Quality Evaluation of Equipment
5 Installation Requirements of Test Piece and Arrangement of Measuring Points
5.1 Installation Requirements
5.2 Arrangement of Measuring Points
6 Selection of Test Pieces
7 Procedures of Seismic Evaluation Test
8 Seismic Evaluation Test Procedures
8.1 Dynamic Characteristics Exploratory Test
8.1.1 Purpose of Dynamic Characteristics Exploratory Test
8.1.2 Methods of Dynamic Characteristics Exploratory Test
8.2 Seismic Performance Test
8.2.1 Requirements on Equipment Performance in Seismic Performance Test
8.2.2 Seismic Performance Test Method
8.2.3 Limitation of Single-direction Test Method
8.2.4 Limitation of Single Frequency Test
8.2.5 Requirements for Seismic Performance Test
8.2.6 Single-frequency Wave Method
8.2.6.1 Requirements for Single-direction Test
8.2.6.2 Seismic Performance Test of Valve
8.2.7 Multi-frequency Wave Method
8.2.8 Time Interval for Loading
8.2.9 Limit Test
8.3 Final Inspection
9 Critical Damping Ratio
10 Evaluation Test Report
Appendix Examples of Equipment Classified as Seismic Category I in Pressurized Water Reactor Nuclear Power Plant
Bibliography
