MS38 Reliability Reseach on the Hardware for Smart Isolation in NPPs

Associate Prof. Naxin Dai: nxdai@guet.edu.cn

Session Chairs:
Naxin Dai, Associate Prof.,University of South China, nxdai@guet.edu.cn

Abstract of the special session:
This Special Session concentrates on the seismically super-reliable smart isolation system for Nuclear Power Plants(NPPs) based on the existing Reactor Scram Control System (RSCS), which can continuou operation 24 hours in a day without stopping machines, can work with high reliability under earthquakes and can supply ultra-high electric power without time delay for the semi-active control, to realize Seismic Probabilistic Risk Assessment (SPRA) and seismic margins studies. These advantages would be almost a perfect solution for the question of unreliability to the semi-active control system, because this system requires the real-time feedback of signals such as drifts, velocity and acceleration in buildings and bridges, where the ultra-high electricty supply is very difficult and astable.
Through the parallel access of the seismically smart isolation system to the existing reactor scram control system, Super-reliability of smart system would been studied; The research on reducing large displacement for smart system in the isolation story, which induced that the anti-seismic capacity of vessels system is becoming strong, would also be done; Another research is that the long period ground motion would be finished in order to compare seismic response between the smart isolation and the passive;Due to this smart isolation, the degree of enlarging the seismic margin would also be investigated. In other words, how much can the maximum ground motion(SSE) run up to? These findings of smart system would be also compared with passive isolation; At the same time, the research and development would be done for a novel complex dampers, which includes two smart materials, namely MR and PZT, in order to enlarge the damping force and adjustable coefficient for the smart isolation for the overweighted equipments in NPPs. The parameters of nature ruber bearings (NRB) would be changed after these bearings suffered from nuclear radiation, and the seismic isolation performance of bearings system would also to be degrated. The knowedges of this reducing performance would help to understand the reliablilty for this seismic isolation. The purpose of performing a seismic PRA is to estimate the probability of core melt and radioative release from a nuclear plant due to earthquakes.
The results and findings of this project are of basic/enough theoretical and practical significance for being a pioneer of a new domain of research on the seismically smart isolation for NPPs.