Westinghouse Electric Corporation

Paul H Dawson

John J Wilhelm

Robert H Sturges, Jr

Gregory L Calhoun

Arthur W Kramer

Roger Graham Byford

Joseph J Birsa

A nozzle dam for providing a fluid-tight seal across a primary fluid nozzle in the plenum of a nuclear steam generating vessel includes an elongated shaft coupled at one end thereof to an anchor assembly frictionally engageable with the inner surface of the nozzle to anchor the dam in place and a fluid-impermeable seal apparatus coupled to the shaft and closing the nozzle and frictionally engageable with the inner surface thereof to form a fluid-tight seal. The seal apparatus includes a circular plate disposable in wedging frictional engagement with a frustoconical portion of the nozzle inner surface. The shaft extends through a central aperture in the plate and is threadedly engaged with a nut which holds the plate in place. The anchor assembly includes a foldable tripod arrangement coupled to the shaft in such a way that movement of the shaft toward the seal plate effects an increase in the frictional anchoring force. The seal assembly also includes an inflatable portion. In one embodiment this inflatable portion extends around the perimeter of the seal plate and is readily expandable. In another embodiment the inflatable portion includes inflatable pillows disposed between the seal plate and the anchor assembly and inflatable for completely closing the nozzle. A foldable tripod centering mechanism and a shaft tensioning tool are also disclosed.

Non-bolted ringless nozzle dam

A manipulator control system uses a microprocessor to compute appropriate control parameters in order to maintain constant tangential velocity of a spray nozzle in relation to the inside surface of a spherical portion of a nuclear steam generator. The microprocessor also computes, in one of the three modes of operation, of the control system, appropriate control parameters for maintaining a predetermined distance between the nozzle and the center of the spherical enclosure.

Manipulator control system and apparatus for decontaminating nuclear

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Plum Borough, PA, United States of America

Paul H Dawson