Earthquake resistance problems of electric equipment

Earthquake resistance of electric equipment of nuclear power plants is assessed by calculation, this in cases where it is possible to easily model the assessed equipment on a mechanical system. If this is not so it will be necessary to make experimental verifications, this either by proof testing for equipment designed for single use or by fragility testing of standard equipment. Briefly discussed are the specificities of evaluating earthquake resistance of electric equipment of nuclear power plants according to regulations valid in western countries and in the USSR. In Czechoslovakia there is no legal standard for such testing and therefore the Soviet experience is of special value, mainly because the reactor type is the same and also with respect to the experimental equipment available. (Z.M.)