A Method for In Situ Test and Analysis of Nuclear Plant Equipment

Requalification of equipment in operating nuclear power plants to present-day criteria can be an expensive undertaking; however in situ measurements and data analysis procedures can be used to significantly reduce these costs. The procedures necessary to develop a required response spectrum for an instrument located at an elevated position within a base-fixed enclosure from modal analysis parameter measurements on the enclosure while installed in operating nuclear plant is addressed. Several examples are given to demonstate the ability of the procedures to develop the parameters necessary to predict component elevated responses from postulated enclosure base motion without recourse to analytical structural modeling of the base-fixed structure.