Westinghouse Electric Corporation

Howard L Ott

Robert M Wepfer

Robert M Wilson

Steven A Palm

Tod H Baker

James X Jenko

A pressurizer tank in a pressurized water nuclear reactor is mounted between structural walls of the reactor on a substructure of the reactor, the tank extending upwardly from the substructure. For bearing lateral loads such as seismic shocks, a girder substantially encircles the pressurizer tank at a space above the substructure and is coupled to the structural walls via opposed sway struts. Each sway strut is attached at one end to the girder and at an opposite end to one of the structural walls, and the sway struts are oriented substantially horizontally in pairs aligned substantially along tangents to the wall of the circular tank. Preferably, eight sway struts attach to the girder at 90.degree. intervals. A compartment encloses the pressurizer tank and forms the structural wall. The sway struts attach to corners of the compartment for maximum stiffness and load bearing capacity. A valve support frame carrying the relief/discharge piping and valves of an automatic depressurization arrangement is fixed to the girder, whereby lateral loads on the relief/discharge piping are coupled directly to the compartment rather than through any portion of the pressurizer tank. Thermal insulation for the valve support frame prevents thermal loading of the piping and valves. The girder is shimmed to define a gap for reducing thermal transfer, and the girder is free to move vertically relative to the compartment walls, for accommodating dimensional variation of the pressurizer tank with changes in temperature and pressure.

Pressurizer tank upper support

Vessel structural support system for laterally and vertically supporting a vessel, such as a nuclear steam generator having an exterior bottom surface and a side surface thereon. The system includes a bracket connected to the bottom surface. A support column is pivotally connected to the bracket for vertically supporting the steam generator. The system also includes a base pad assembly connected pivotally to the support column for supporting the support column and the steam generator. The base pad assembly, which is capable of being brought to a level position by turning leveling nuts, is anchored to a floor. The system further includes a male key member attached to the side surface of the steam generator and a female stop member attached to an adjacent wall. The male key member and the female stop member coact to laterally support the steam generator. Moreover, the system includes a snubber assembly connected to the side surface of the steam generator and also attached to the adjacent wall for dampening lateral movement of the steam generator. In addition, the system includes a restraining member of 'flat' attached to the side surface of the steam generator and a bumper attached to the adjacent wall. The flat and the bumper coact to further laterally support the steam generator.

Vessel structural support system

A steam generator upper support arrangement provides restraint to the steam generator during operating and non-operating conditions, for loading forces resulting from seismic and postulated accident conditions, while allowing for free thermal expansion of the steam generator in the radial, lateral, and vertical directions. Four embodiments of the present invention are described. In a first embodiment, inclined bumpers are placed at predetermined angles with respect to the load path, such that as the steam generator is thermally displaced the placement and incline angles of the bumpers will compensate for the expansion and maintain a nominal gap therebetween. In a second embodiment, the variable shim mechanism comprised of cams, bumper rods, and a pivoted linkage between the steam generator and the building structure maintains the nominal gap for the required support. In the third embodiment, a single small snubber is utilized. A pair of opposed, pivotally mounted rigid links arranged in a V-shaped manner are connected between the steam generator and the building structure, their respective apexes joined by the ends of the snubber to resist the loading forces. In the fourth embodiment, a pair of frustoconical sliding shims are disposed between support blocks which are correspondingly slanted to provide a tapered opening for the sliding shims. The shims are pivotally connected to a driveshaft also pivotally connected to the steam generator such that the mechanism maintains a nominal gap between the generator support and the building structure at all times.

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Kiski Township, Westmoreland County, PA, United States of America

Howard L Ott