Piping Support and Gate Valve Behavior during High Level HDR (Heissdampfreaktor) Simulated Seismic Tests

摘要

This paper describes a portion of the analysis and results to date from the SHAM seismic research program, in which the USNRC/INEL was a participant. The program was conducted by Kernforschungszentrum Karlsruhe (KfK) at the decommissioned Heissdampfreaktor (HDR) located near Frankfurt in the Federal Republic of Germany (FRG). The research program included the study of the effects of increasing levels of seismic excitation on a full scale, in situ nuclear piping system containing a naturally aged US 8-in. motor-operated gate valve. In all, 51 experiments were conducted with the piping supported by six different piping support systems, including a typical stiff US piping support system made up of snubbers and rigid struts. Earthquake-like displacement histories were input to servohydraulic shakers attached directly to the piping system. Inputs to the piping system started with a magnitude of 0.6 g ZPA and were stepped up, using the same frequency content, to a maximum of 5 g ZPA. The resulting piping system response produced overload snubber failures and local piping strains of 0.9%. The results of this testing will contribute to the technical basis used for support and development of equipment qualification standards and will help establish the seismic safety margins in piping and piping support system components. 13 figs., 3 tabs. (ERA citation 14:012928)