摘要:
A fuel assembly for a boiling water reactor has a plurality of fuel rods which are mounted in a plurality of spacers disposed at a spacing distance from each other in the axial direction of the fuel element. At least one of the fuel rods has a reduced length. Deflection elements are arranged at least in the upper region of the fuel element in order to improve the dry-out behavior of the assembly. The fuel assembly further includes measures that reduce a loss of pressure caused in the upper region by the deflecting elements so as to improve thermo-hydraulic stability and the shutdown behavior.
摘要:
A fuel element for a nuclear reactor has fuel rods with nuclear fuel guided through spacers. The spacers are equipped with devices that exert a swirling impulse upon a coolant flowing along the fuel rods. In order to present as little flow resistance as possible for the coolant, these swirl-introducing devices have the form of a vane with a spoonlike or bladelike shape and they extend into the coolant flow. Owing to the shape—here the vane is curved in the longitudinal and in the transverse directions—practically all cross sections of the vane have such a high geometrical moment of inertia that even a vane made of a thin sheet metal is sufficiently rigid. Fuel elements configured according to the invention are particularly suitable for use in boiling water nuclear reactors.
摘要:
A hydraulic control rod drive for a nuclear reactor, with a a reactor plenum enclosing the drive, comprises first and second hollow bodies together forming a cylinder and a hollow piston. Working fluid is supplied through one of the hollow bodies. The first hollow body is stationary and the second hollow body is disposed coaxially around the first hollow body. The two hollow bodies define an annular gap therebetween so as to allow axial reciprocating movement of the second hollow body, which forms a carrier body for control elements of the control rod. The second hollow body can be lifted, lowered or suspended by feeding working fluid. A portion of the fluid is removed from the inner space via a throttle passage. A positional measurement system determines the relative displacement of the second hollow body by measuring an ultrasonic measurement path. The system includes an ultrasound reflector and an ultrasonic transducer rigidly mounted remote from the ultrasound reflector. Provisions are made for venting the inner space through venting channels which open into the reactor plenum at a security distance from the measurement path so as not to adversely affect the ultrasonic measurement.
摘要:
A nuclear reactor includes a pressure vessel enclosing a plenum, a core in the pressure vessel, a pressure-tight encapsulation in the pressure vessel communicating with the plenum, and control members passing through the encapsulation and having first and second control member segments. The second control member segment has an absorber part to be at least partly inserted into and retracted out of the core for controlling reactivity. The first control member segment has an outer drive part. A control drive is associated with the outer drive part for adjusting the control member along the longitudinal direction thereof. An antieject device for restraining ejection of the control member out of the pressure vessel due to a leak at the encapsulation includes a rod coupling having a disengageable coupling catch interconnecting the first and second control member segments and remaining in engagement during normal control motion of the control member and means for unlocking the coupling catch. After disconnection the second control member segment and the absorber part remain in the core for assuming a position fully inserted into the core.
摘要:
A nuclear reactor fuel assembly includes a fuel assembly base, a fuel assembly head and mutually parallel fuel rods containing nuclear fuel and extending between the fuel assembly head and the fuel assembly base. A water tube having first and second open ends extends parallel to the fuel rods. The first end of the water tube grips and is held at the fuel assembly base. An elongated extension body has first and second ends. The second end of the extension body grips and is held at the fuel assembly head. The second end of the water tube is screwed into the first end of the elongated extension body, or the first end of the elongated extension body is screwed into the second end of the water tube. The elongated extension body has two mutually coaxially disposed partial bodies. One of the partial bodies has the second end of the extension body and the other of the partial bodies has the first end of the extension body. One of the partial bodies is screwed into the other of the partial bodies. A check nut may be seated on the one partial body which is screwed into the other partial body and the check nut is braced against the other partial body.
摘要:
A fuel assembly for a boiling water reactor includes approximately mutually parallel fuel rods in a bundle having upper and lower ends. A skeleton holding the bundle has a handle, an upper tie plate retained on the handle at the upper end of the bundle, a lower tie plate at the lower end of the bundle, and at least one support element joining together the lower tie plate and the upper tie plate. The skeleton and the bundle are inserted in a fuel assembly case. A redundant support device holds the lower tie plate, the fuel assembly case and the upper tie plate together, when the handle is lifted.
摘要:
Disclosed are immunogenic Nogo receptor-1 polypeptides, Nogo receptor-1 antibodies, antigen-binding fragments thereof, soluble Nogo receptors and fusion proteins thereof and nucleic acids encoding the same. Also disclosed are Nogo receptor antagonist polynucleotides. Also disclosed are compositions comprising, and methods for making and using, such Nogo receptor antibodies, antigen-binding fragments thereof, soluble Nogo receptors and fusion proteins thereof, nucleic acids encoding the same and antagonist polynucleotides.
摘要:
A lower nozzle for use in a nuclear fuel assembly provided. The lower nozzle is of the type having an axis and comprising a transverse lower tie plate for channelling the coolant through the lower tie plate and a tubular skirt extending axially from the periphery of the lower tie plate, the skirt delimiting an axial housing closed at one end by the lower tie plate and open at the opposite end, a debris filter configured for axial insertion in the housing and snap-fit springs for retaining the debris filter in the housing after insertion. The springs are configured to shift the debris filter axially towards the lower tie plate.
摘要:
Disclosed are immunogenic Nogo receptor-1 polypeptides, Nogo receptor-1 antibodies, antigen-binding fragments thereof, soluble Nogo receptors and fusion proteins thereof and nucleic acids encoding the same. Also disclosed are Nogo receptor antagonist polynucleotides. Also disclosed are compositions comprising, and methods for making and using, such Nogo receptor antibodies, antigen-binding fragments thereof, soluble Nogo receptors and fusion proteins thereof, nucleic acids encoding the same and antagonist polynucleotides.
摘要:
In order to obviate the use of supporting rods, an upper end piece of a coolant tube penetrates a fuel assembly head of a nuclear reactor fuel assembly and is supported on the fuel assembly head. A lower end piece of the coolant tube is fastened to and supported by a fuel assembly foot, in particular with rods of partial lengths. A supporting skeleton therefore includes the foot and the coolant tube with spacers. The fuel assembly head and a handle are placed on the skeleton and screwed onto the coolant tube after fuel rods are pushed into meshes of the spacer.