Field vibration test results and design for reactor coolant piping systems of ATR 'Fugen'

In most Japanese Nuclear Power Plants, the field vibration test on the important piping systems has been performed to verify the appropirateness of the seismic design and the integrity of the pipe work. For a prototype Heavy-Water Reactor 'FUGEN' (165-MWe heavy-water-moderated, boiling light-water-cooled pressure tube reactor, developed along one of the Japan's national projects, and reached criticality on March, 1978), the reactor coolant piping systems are connected with the pressure tube, the steam drums and the recirculation pumps. The steam drums are set in the top level and the recirculation pumps in the bottom level. This layout is complicated in comparing with other type of Reactors. The seismic analysis of the main piping systems in the FUGEN was performed by means of the model analysis method using the floor response spectrum. (orig.)