Seismic Test Result of Motor-Operated Valve Actuators for Nuclear Power Plant

Functional requirements of motor-operated valves provided in nuclear power plants during an earthquake have been previously evaluated via seismic tests and so forth; however, since the response acceleration has increased in line with a recent reassessment of standard earthquake ground motions, it is necessary to evaluate functional maintenance with respect to high acceleration. From the viewpoint of equipment fragility in seismic Probability Risk Assessment (PRA) also, it is necessary to determine practical functionality. Here, we used a resonant shaking table (see Ref. [1]) in the Central Research Institute of the Electric Power Industry (CRIEPI), which is capable of seismic tests at acceleration levels that have been unachievable until now, and in seismic tests carried out on motor-operated valve actuators, we obtained results confirming that operability of active components used with an existing design was achieved even at large accelerations exceeding 20×9.8 m/s²,. The results of seismic operability of motor-operated valve actuators will be applied to a fragility analysis of seismic PRA.