A combined blade guide and exchange tool, include a blade guide tool having a lower end and an upper end and a plurality of frame rails supporting a pair of lower collet housings at a lower end of the blade guide tool. A pair of fuel support grapple actuating rods are supported between the plurality of frame rails and have a first end engaging a pair of collets within the pair of lower collet housings and a second end disposed at the upper end of the blade guide tool. A blade exchange tool is releasably mounted to the upper end of the blade guide tool and includes a pair of upper collets for engaging the pair of fuel support grapple actuating rods. The blade exchange tool further including a slider and hook assembly attached to a cable guided by the blade exchange tool and adapted for engaging a control rod.

Provided are a welding apparatus and a method, including a welding torch, a wire nozzle, a support stand that supports the welding torch and the wire nozzle with a predetermined distance therebetween, and a first support mechanism that supports the support stand so that the support stand is rotatable around a first support axis that is along a direction in which the welding torch and the wire nozzle are arranged.

A reactor measurement-pipe maintenance clamp apparatus includes a first clamp mechanism and a second clamp mechanism. The first clamp mechanism includes clamps to fix the measurement pipe between the clamps, first clamp operation bolts that are allowed to be turned by remote control from above a reactor core, and wedge mechanisms to convert the turning of the clamp operation bolts to displacement of the clamps in a radial direction of the diffuser to generate clamping forces for securing the measurement pipe. The second clamp mechanism includes a support clamp to hold the support, a second clamp operation bolt that is allowed to be turned by remote control from above the reactor core, and a wedge mechanism to convert the turning of the second clamp operation bolt to displacement of the support clamp in a tangential direction of the diffuser to generate clamping force for fixing the support.

A water jet peening apparatus includes: a nozzle, which is arranged in water and has a mouth from which water is jetted out; a detecting device, which is arranged in the water and detects sound in at least a part of a period during which the water is being jetted out from the mouth; and a processing device, which determines, based on a result of the detection by the detecting device, presence or absence of abnormality in the nozzle.

Methods for nuclear power plant maintenance which reduces outage time while a polar crane is maintained. In some examples, the method includes the steps of placing an auxiliary crane on a set of rails of a polar crane, using the auxiliary crane to perform maintenance work while the polar crane is maintained, and removing the auxiliary crane after maintenance work on the polar crane is completed. In some further examples, the method includes placing a second auxiliary crane on the set of rails. Still in other example, bridge motors are used to turn the rails, allowing the auxiliary crane to reach every area of the plant floor.

Systems join with a control rod drive and expand or contract to displace elements necessary for decoupling. Joining structures affix to on sides of the control rod drive allow discriminatory jacking by a powered drive also in contact with the control rod drive. A moveable piston tube can be displaced by this jacking with hundreds or thousands of pounds of force with respect to the control rod drive. Probes and other instrumentation and sensors are useable in the systems to accurately measure any of piston tube displacement, temperature, malfunction; drive power status, displacement or speed; and communications status. Manual interaction with the systems are not required during the jacking, and installation and removal of the systems requires no tools or great amount of time or effort. Through remote operation and brief installation, human exposure to radiation about control rod drives is minimized.

A system for servicing a nuclear reactor module comprises a crane operable to attach to the nuclear reactor module, wherein the crane includes provisions for routing signals from one or more sensors of the nuclear reactor module to one or more sensor receivers.

A method whereby signals that are output by replacement SPNDs are converted into equivalent signals that would have been detected by legacy SPNDs for input to the legacy software. The replacement SPNDs have a different geometry than the legacy SPNDs and also have a different neutron sensitivity than the legacy SPNDs. The replacement SPNDs are subjected to a neutron flux in a core of a reactor and responsively output a set of signals. The set of signals and the geometry of the replacement SPNDs are employed to create a characterization of the neutron flux in the form of a curve that represents flux as a function of location along the core of the reactor. The legacy geometry of the legacy SPNDs is then employed to find the values on the curve that correspond with the positions where the legacy SPNDs had been located to create inputs for the legacy software.

A combined blade guide and exchange tool, include a blade guide tool having a lower end and an upper end and a plurality of frame rails supporting a pair of lower collet housings at a lower end of the blade guide tool. A pair of fuel support grapple actuating rods are supported between the plurality of frame rails and have a first end engaging a pair of collets within the pair of lower collet housings and a second end disposed at the upper end of the blade guide tool. A blade exchange tool is releasably mounted to the upper end of the blade guide tool and includes a pair of upper collets for engaging the pair of fuel support grapple actuating rods. The blade exchange tool further including a slider and hook assembly attached to a cable guided by the blade exchange tool and adapted for engaging a control rod.

A nuclear reactor is provided. The reactor includes a reactor pressure vessel housing plural fuel rods containing fissile material, the reactor pressure vessel having an upper, removable, vessel head. The reactor further includes control rods, each made of a neutron-absorbing material. The control rods are inserted into the reactor through the vessel head and between the fuel rods to control the rate of the fuel rods' fission reaction. The control rods are movable over a normal range of insertion positions relative to the vessel head to control the power output of the reactor when it is critical and generating useful power, and to put the reactor in a sub-critical shutdown state. The reactor further includes control rod drive mechanisms carried by the vessel head and operable to drive the movements of the control rods. The control rod drive mechanisms are controllable to release the control rods when a vessel opening operation is performed in which the reactor is in the shutdown state and the vessel head is lifted upwards from the reactor pressure vessel such that the control rods slide therethrough to remain stationary relative to the fuel rods to maintain the shutdown state. The reactor further has monitoring unit to identify whether a control rod is accidently lifting with the vessel head.