Electric Power Research Institute Incorporated

Robert A Lee

Stephen C Jens

Paul F Viola

Christos Athanassiu

Paul R Belkus

Michael W Osborne

Bernard Sawaf, Deceased

Boyd P Brooks

A sliding lance guide flexible lance system (10) is attached to a hand hole (12) of a nuclear power plant steam generator by means of flange (14) of tilt module (16). A rail (18) extends from the tilt module (16) to a support stand (20) and is attached to the stand (20) by a pivot (22) so that the rail (18) is free to rotate with the tilt module (16). A tilt drive motor (24) is attached to the tilt module (16). A flexible lance (26) extends into the rail (18) for extension through a lance guide shoe (27). The lance guide shoe (27) deflects the lance from the rail (18) into the tube gap of the steam generator. The lance guide shoe (27) is slideably mounted in the rail (18), and is attached to a lance guide belt (30), which extends within and along the rail (18). Similarly, the flexible lance (26) extends within and along the rail (18). A lance guide belt sprocket drive (40) is mounted on support (33) to engage the lance guide belt (30). A similar flexible lance sprocket drive (42) is mounted on the support (33) to engage the flexible lance (26).

Sliding lance guide flexible lance system

An apparatus (10) for the location and removal of foreign objects from a difficult to access geometry utilizes a flexible lance (12) formed of individual hose bar segments (14) strung on cables (16) to give a structure that is flexible along its length and fairly rigid in a direction transverse to its length. Extending from working channels (18) of nozzle block (20) of the lance (12) are a pair of multi-prong retrievers (22). A miniaturized Videoprobe camera (24) is provided in the nozzle block (20) between the two retrievers (22). The retrievers are each connected to an actuating cable (26), which extends through the flexible lance (12) to a manual control (28). The camera (24) is connected by a cable (30) to suitable video processing circuits for generation of images on a video display (32). The cable (30) also houses a fiber optic bundle which conveys light to the area being serviced by the lance (12). The flexible lance (12 ) extends through a transporter (34), which positions the nozzle block end of the lance (12) opposite a portion of a steam generator or other difficult to access geometry. The transporter (34) moves along a transport rail (36) to move the nozzle block end of the lance (12) into position. The lance (12) is then advanced through the transporter (34) to move the nozzle block end into the difficult to access geometry and retracted to withdraw the nozzle block end from the difficult to access geometry.

In bundle foreign object search and retrieval apparatus

A system (10) for lancing sludge deposits (12) from within a bundle (14) of vertically extending steam generator tubes (16) of a PWR steam generator secondary side assembly (18) has a flexible lance (28) mounted in a lance guide/housing transporter (30). The transporter (30) is movable along blowdown lane (20) to position end (32) of the flexible lance opposite one of the inter-tube lanes (26) so that the flexible lance (28) may be inserted along the selected inter-tube lane (26). A rigid lance guide (34) on the transporter (30) has a curved end (36) configured to turn the flexible lance (28) at a chosen angle, such as 90.degree., so that the flexible lance (28) will be fed into the selected inter-tube lane (26). The transporter has a drive (37) for advancing the flexible lance (28) through end (36) of the lance guide (34) and into the inter-tube lane (26). The flexible lance (28) includes a flexible plastic extrusion (38) with a plurality of hollow, flexible metal conduits (40) within the plastic extrusion (38) to extend lengthwise along the lance (28). The nozzle block (44) has nozzles 48, 50 and 52 so that all portions of the sludge deposits (12) adjacent to the selected inter-tube lane (26) can be reached by the flexible lance (28).

Flexible lance for steam generator secondary side sludge removal

A system (10) for lancing sludge deposits (12) from within a bundle (14) of vertically extending steam generator tubes (16) of a PWR steam generator secondary side assembly (18) has a flexible lance (28) mounted in a lance guide/housing transporter (30). The transporter (30) is movable along blowdown (20) to position end (32) of the flexible lance opposite one of the inter-tube lanes (26) so that the flexible lance (28) may be inserted along the selected inter-tube lane (26). A rigid lance guide (34) on the transporter (30) has a curved end (36) configured to turn the flexible lance (28) at a chosen angle, such as 90.degree., so that the flexible lance (28) will be fed into the selected inter-tube lane (26). The transporter has a drive (37) for advancing the flexible lance (28) through end (36) of the lance guide (34) and into the inter-tube lane (26). The flexible lance (28) includes a flexible plastic extrusion (38) with a plurality of hollow, flexible metal conduits (40) within the plastic extrusion (38) to extend lengthwise along the lance (28). The nozzle block (44) has nozzles b 48, 50 and 52 so that all portions of the sludge deposits (12) adjacent to the selected inter-tube lane (26) can be reached by the flexible lance (28).

Flexible lance for steam generator secondary side sludge removable

A microprocessor-based valve motor control system which provides control, predictive control and diagnostic functions for a motor operated valve. A microprocessor periodically tests the status of the motor operated valve, and turns off the valve's motor if certain predefined criteria for the valve stem position and the valve stem load are satisfied. The periodic testing by the microprocessor includes the testing of a position criterion (comparing both the current valve stem position signal and a predicted stem position with a preselected target position); and a stem load criterion (comparing both the current valve stem load and a predicted stem load with a preselected maximum desirable stem load). When the control system is being used with a gate valve for fully opening and fully closing a valve, the control logic can use either a predicted position criterion or a predicted stem load criterion to determine when to turn off the valve motor. When the control system is being used with a flow control valve, the use of a predicted position criterion minimizes overshoot problems which cause the motor to be reversed one or more times while moving to a target position. Motor overload protection is provided by periodically measuring the actual load on the motor and turning off the motor if the measured motor load exceeds any one of a plurality of preselected maximum motor load values for a corresponding period of time.

Microprocessor-based control and diagnostic system for motor operated

There is described a microprocessor-based valve motor control system which provides control, predictive control and diagnostic functions for a motor operated valve. A valve stem position sensor measures the stem position and a load sensor measures the load on the valve stem. When the valve is being opened, the system predicts the position of the valve stem at a predefined time in the future and turns off the motor if the predicted valve stem position is beyond a preselected open valve position. When said valve is being closed, the system predicts the load on the valve stem at a predefined time in the future and turns off the motor if the predicted load value exceeds a preselected maximum desirable stem closing load.

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Stoneham, MA, United States of America

Robert A Lee