摘要:
A nuclear reactor fuel assembly including: an upper tie plate having apertures to receive and support fuel rods of a fuel bundle; the fuel bundle includes an array of the fuel rods mounted and housed in the walls of a channel, and a load bearing or non-load bearing debris shield may be mounted in the upper tie plate, wherein the debris shield is porous to prevent the passage of debris. The debris shield is mounted in the frame of the upper tie plate. The debris shield can be either a removable unit, or it can be attached as a permanent integrated structure within the upper tie plate. The upper tie plate frame is also porous, e.g., has small vertical openings to allow fluid to pass through the frame and block passage of debris. The openings in the frame increase the effective flow area of passages through the upper tie plate and thereby compensate or offset any flow restrictions due to the debris shield. Preventing debris falling into the fuel bundle is expected to assure the operational life of the fuel assembly by reducing the risk of fuel rod failure and premature discharge from the reactor core.
摘要:
A method to capture, retain and remove debris falling into a nuclear reactor fuel bundle assembly including a bundle of fuel rods mounted below an upper tie plate and housed in a hollow metal channel, the method includes: inserting a debris shield in the upper tie plate; maintaining the shield in the upper tie plate and above the fuel rods, and water rods, while the fuel bundle assembly is in an operating nuclear reactor core; capturing debris falling in the fuel assembly on the debris shield; after capturing the debris, removing the fuel bundle assembly with the inserted debris shield from the nuclear reactor core to a maintenance/fuel inspection pool and thereafter removing the debris shield from the upper tie plate, cleaning and then reinserting the cleaned debris shield back into the upper tie plate, and moving the fuel bundle assembly from the maintenance/fuel inspection pool back into the nuclear reactor core.
摘要:
A method to capture, retain and remove debris falling into a nuclear reactor fuel bundle assembly including a bundle of fuel rods mounted below an upper tie plate and housed in a hollow metal channel, the method includes: inserting a debris shield in the upper tie plate; maintaining the shield in the upper tie plate and above the fuel rods, and water rods, while the fuel bundle assembly is in an operating nuclear reactor core; capturing debris falling in the fuel assembly on the debris shield; after capturing the debris, removing the fuel bundle assembly with the inserted debris shield from the nuclear reactor core to a maintenance/fuel inspection pool and thereafter removing the debris shield from the upper tie plate, cleaning and then reinserting the cleaned debris shield back into the upper tie plate, and moving the fuel bundle assembly from the maintenance/fuel inspection pool back into the nuclear reactor core.
摘要:
A method to prevent debris falling into a nuclear reactor fuel assembly including a bundle of fuel rods mounted below an upper tie plate and housed in a channel including: inserting a debris shield in the upper tie plate; maintaining the shield in the upper tie plate and above the fuel rods, while the fuel assembly is in an operating nuclear reactor core; flowing coolant through the bundle and the debris shield during operation of the nuclear reactor core, and capturing or deflecting debris falling in the fuel assembly with the debris shield.
摘要:
A nuclear reactor fuel bundle assembly including: a fuel bundle including an array of fuel rods and water rods mounted in an upper tie plate and housed in walls of a channel, and a pore type debris shield mounted at least partially in the channel, above or below the upper tie plate, the shield extending to or over the walls of the channel, whereby deflecting and/or capturing falling debris from entering the fuel assembly, wherein the shield is design to be durable, yet flexible, and porous.
摘要:
A nuclear reactor fuel bundle assembly including: a fuel bundle including an array of fuel rods and water rods mounted in an upper tie plate and housed in walls of a channel, and a pore type debris shield mounted at least partially in the channel, above or below the upper tie plate, the shield extending to or over the walls of the channel, whereby deflecting and/or capturing falling debris from entering the fuel assembly, wherein the shield is design to be durable, yet flexible, and porous.
摘要:
A rod assembly for a fuel bundle of a nuclear reactor may include an upper end piece, lower end piece and a plurality of rod segments attached between the upper and lower end pieces and to each other so as to form an axial length of the rod assembly. The rod assembly may include an adaptor subassembly provided at given connection points for connecting adjacent rod segments or a given rod segment with one of the upper and lower end pieces. The connection points along the axial length of the rod assembly may be located where the rod assembly contacts a spacer in the fuel bundle. One (or more) of the rod segments may include an irradiation target therein for producing a desired isotope when a fuel bundle containing one (or more) rod assemblies is irradiated in a core of the reactor.
摘要:
In a method of producing isotopes in a light water power reactor, one or more targets within the reactor may be irradiated under a neutron flux to produce one or more isotopes. The targets may be assembled into one or more fuel bundles that are to be loaded in a core of the reactor at a given outage. Power operations in the reactor irradiate the fuel bundles so as to generate desired isotopes, such as one or more radioisotopes at a desired specific activity or stable isotopes at a desired concentration.
摘要:
A mower blade bracket apparatus for safely changing mower blades includes a bracket body comprising a first half adjustably coupled to a second half to adjust for a distance between a first distal end and a second distal end. The first distal end and the second distal end have a first mounting aperture and a second mounting aperture extending therethrough, respectively. A pair of mounting bolts is coupled to the bracket body. The pair of mounting bolts is engaged with the first mounting aperture and the second mounting aperture to selectively engage a skirt of a lawn mower. A blade sleeve is coupled to the bracket body. The blade sleeve slidingly receives a blade of the lawn mower.
摘要:
Methods and devices are provided for manipulating the glymphatic system to improve cognitive and other cranial or brain functions of a subject. In particular, pressure is alternately applied to the jugular veins on either side of the subject's neck to generate a to and fro movement of cranial fluids.