Abstract: A method and apparatus for a boiling water reactor (BWR) jet pump inlet mixer compliant stop. The inlet mixer compliant stop may be installed in a pocket area between a riser pipe and an inlet mixer of a BWR jet pump assembly. The inlet mixer compliant stop includes a main body and a foot that are separated via the tightening of one or more jacking bolts used to connect the main body and the foot. A cold spring attached to the main body provides a lateral force that is imparted on the inlet mixer, to force the inlet mixer away from a centerline of the riser pipe. A precise lateral force may be imparted on the inlet mixer by gauging a width of a gap between opposing bosses on a front face of the main body and a distal end of the cold spring. The inlet mixer compliant stop imparts a greater lateral force on the inlet mixer as the jacking bolts are tightened, further separating the main body from the foot, as the gap between the opposing bosses is reduced.

Abstract: A remote pulse TDR liquid level measurement system and method may include inserting a probe into a body of water. The probe has a probe/air interface, and the body of water includes an air/water interface. A narrow pulse is remotely transmitted to the probe via a coaxial cable. A first impedance mismatch is received from the probe/air interface in a form of a positive reflected pulse, and a second impedance mismatch is received from the air/water interface in a form of a negative reflected pulse. A time between the positive reflected pulse and the negative reflected pulse is calculated, and the time is converted to a distance, the distance being indicative of the water level.

Abstract: A method and apparatus for securely fastening a pipe collar or a bracket to a riser pipe of a boiling water reactor (BWR) jet pump assembly. A pipe plug assembly includes an angled pipe plug that acts as a wedge to expand a bushing assembly as the pipe plug is drawn into the overall pipe plug assembly. Expansion of the bushing assembly allows a tight tolerance to exist between an outer diameter of the pipe plug and an inner diameter of the collar/bracket and riser pipe. Expansion of the bushing assembly allows a straight hole to be match drilled into the collar/bracket and riser pipe, thereby avoiding a more complicated tapered hole to be drilled into the collar/bracket and riser pipe. An ensuing tight fit between the pipe plug assembly, the collar/bracket and the riser pipe mitigates vibration of components and minimizes leakage to acceptable levels for use in the flooded environment of the annulus region where the jet pump assembly exists in the BWR.

Abstract: A method and apparatus for repairing and/or reinforcing a Boiling Water Reactor (BWR) jet pump riser pipe. The repair includes attaching two collars to the riser pipe using match drilling to drill holes through the collars and the riser pipe and plugging the holes with expandable plugs. Support columns are attached to the collars. Brace supports are slideably attached to the support columns. Gaps between each brace support and its respective collar are then narrowed as ratchet bolts may apply a force that pulls downward on an upper collar and pulls upward on a lower collar, thereby exerting a compression force on the riser pipe. A clamp assembly may also be located between the two collars that applies a hoop force on the riser pipe.

Abstract: A remote pulse TDR liquid level measurement system and method may include inserting a probe into a body of water. The probe has a probe/air interface, and the body of water includes an air/water interface. A narrow pulse is remotely transmitted to the probe via a coaxial cable. A first impedance mismatch is received from the probe/air interface in a form of a positive reflected pulse, and a second impedance mismatch is received from the air/water interface in a form of a negative reflected pulse. A time between the positive reflected pulse and the negative reflected pulse is calculated, and the time is converted to a distance, the distance being indicative of the water level.

Abstract: An assembly for securing a riser brace to a riser pipe includes brackets configured to engage a yoke of the riser brace and clamp bands that are configured to extend around the riser pipe and connect to the brackets. The assembly also includes a connection that connects the assembly as a unit and is configured to adjust the tightness of the assembly around the riser pipe and riser brace.

Abstract: An embodiment of the present invention takes the form of an apparatus or system that may reduce the level of vibration experienced by an inlet riser or other similar object within a reactor pressure vessel. An embodiment of the present invention may eliminate the need for welding the riser brace to the inlet riser. An embodiment of the present invention provides at least one riser brace clamp that generally clamps the riser brace to the inlet riser. After installation, the riser brace clamp may lower the amplitude of, and/or change the frequency of, the vibration experienced by the inlet riser.

Abstract: A method and apparatus for a boiling water reactor (BWR) jet pump inlet mixer compliant stop. The inlet mixer compliant stop may be installed in a pocket area between a riser pipe and an inlet mixer of a BWR jet pump assembly. The inlet mixer compliant stop includes a main body and a foot that are separated via the tightening of one or more jacking bolts used to connect the main body and the foot. A cold spring attached to the main body provides a lateral force that is imparted on the inlet mixer, to force the inlet mixer away from a centerline of the riser pipe. A precise lateral force may be imparted on the inlet mixer by gauging a width of a gap between opposing bosses on a front face of the main body and a distal end of the cold spring. The inlet mixer compliant stop imparts a greater lateral force on the inlet mixer as the jacking bolts are tightened, further separating the main body from the foot, as the gap between the opposing bosses is reduced.

Abstract: A method and apparatus for securely fastening a pipe collar or a bracket to a riser pipe of a boiling water reactor (BWR) jet pump assembly. A pipe plug assembly includes an angled pipe plug that acts as a wedge to expand a bushing assembly as the pipe plug is drawn into the overall pipe plug assembly. Expansion of the bushing assembly allows a tight tolerance to exist between an outer diameter of the pipe plug and an inner diameter of the collar/bracket and riser pipe. Expansion of the bushing assembly allows a straight hole to be match drilled into the collar/bracket and riser pipe, thereby avoiding a more complicated tapered hole to be drilled into the collar/bracket and riser pipe. An ensuing tight fit between the pipe plug assembly, the collar/bracket and the riser pipe mitigates vibration of components and minimizes leakage to acceptable levels for use in the flooded environment of the annulus region where the jet pump assembly exists in the BWR.

Abstract: A method and apparatus for repairing and/or reinforcing a Boiling Water Reactor (BWR) jet pump riser pipe. The repair includes attaching two collars to the riser pipe using match drilling to drill holes through the collars and the riser pipe and plugging the holes with expandable plugs. Support columns are attached to the collars. Brace supports are slideably attached to the support columns. Gaps between each brace support and its respective collar are then narrowed as ratchet bolts may apply a force that pulls downward on an upper collar and pulls upward on a lower collar, thereby exerting a compression force on the riser pipe. A clamp assembly may also be located between the two collars that applies a hoop force on the riser pipe.

Abstract: An embodiment of the present invention takes the form of an apparatus or system that may reduce the level of vibration experienced by an inlet riser or other similar object within a reactor pressure vessel. An embodiment of the present invention may eliminate the need for welding the riser brace to the inlet riser. An embodiment of the present invention provides at least one riser brace clamp that generally clamps the riser brace to the inlet riser. After installation, the riser brace clamp may lower the amplitude of, and/or change the frequency of, the vibration experienced by the inlet riser.

Abstract: An assembly for securing a riser brace to a riser pipe includes brackets configured to engage a yoke of the riser brace and clamp bands that are configured to extend around the riser pipe and connect to the brackets. The assembly also includes a connection that connects the assembly as a unit and is configured to adjust the tightness of the assembly around the riser pipe and riser brace.

Abstract: An embodiment of the present invention takes the form of an apparatus or system that may reduce the level of vibration experienced by an inlet riser or other similar object within a reactor pressure vessel. An embodiment of the present invention may eliminate the need for welding the riser brace to the inlet riser. An embodiment of the present invention provides at least one riser brace clamp that generally clamps the riser brace to the inlet riser. After installation, the riser brace clamp may lower the amplitude of, and/or change the frequency of, the vibration experienced by the inlet riser.