Multiple independent pipe support motions

Efforts under the Mechanical Piping Benchmarks Program have continued through FY 83. Major work areas during this period were the investigation of multiple independent support motion (ISM) analysis methods and the confirmation of analysis methods by the consideration of and comparison to piping test results (physical benchmarks). In the study of ISM analysis methods, response predictions based on ISM response spectrum methods and alternate seismic anchor movement (SAM) analysis methods are compared to ISM time history results for various nuclear power plant piping configurations. Two physical benchmark confirmatory evaluations, the Indian Point Rigid Strut configuration and the Extended Z Bend ANCO test T6R1R, were completed. The former involved the analytical simulation of a snap back test of a feedwater line in the Indian Point Nuclear Power Plant Unit 1. The latter involved the blind prediction of the response of a simple pipe configuration seismically excited by three pipe mounted actuators. The correspondence of results achieved for the snap back test were only fair. The correspondence of results for the Z bend, as assessed by an alternate NRC contractor, were good. The physical benchmarking is being extended to the evaluation of larger and branched systems subjected to multiple independent excitations in a cooperative program between NRC, EPRI and ANCO Engineers, Inc