Progress of a research program on seismic base isolation of nuclear components Original Research Article

Development of an evaluation code and related test program have been conducted to provide the technical base of the seismic base isolation of nuclear components. In the Phase I (FY1991–FY1995) of the research, a methodology and a computer code Ver.1 for evaluating the effect of seismic base isolation of nuclear components were developed. Case study was carried out on the effectiveness of base isolation of emergency transformer. Difference of input earthquake motion, type of isolation device and influence of the soil property were studied. Case study of a cost/benefit analysis in introducing the base isolation to emergency transformer was tried as an application of the computer code. As the Phase II (FY1996–FY2000), in order to obtain the test data of component base isolation systems, a verification test program, in which the test utilizing the real earthquake and the test by a shaking table are to be carried out, has been initiated since FY1996. In the tests, dynamic response and failure mode of base isolation systems will be examined. This paper overviews the progress of Phase I and II researches.