Abstract:
A device for guiding a control cluster consisting of several absorbing rods consisting of a casing in which are mounted continuous-guiding sleeves each provided with at least one cylindrical slide suitable for the vertical guiding of a rod, and each open with a vertical slot emerging in the slide. Each guiding slide (631, 641) is associated with two orifices (635, 645) forming a hollow in the two lips (633, 643) of the slot (632, 642) so that, when a rod (31) is in contact with the lips, the interior of the slide communicates with the slot.
Abstract:
Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.
Abstract:
Coupler for absorber rods being suspended during operation of nuclear reactors including a plurality of actuating elements being movable for individually and jointly releasing the coupler, the movement of each of the actuating elements for releasing the coupler being independently controllable.
Abstract:
A self-actuated mechanism within a safety assembly in a liquid metal nuclear reactor comprising sensor fuel pins located in a reactor coolant flow path, a sensor bulb containing NaK located near the upper end of the sensor fuel pins and in the reactor coolant flow path, and a sensor tube connecting the sensor bulb to a metal bellows and push rod. The motion of the push rod resulting from the temperature dependent change in the NaK volume actuates a safety rod release mechanism when a predetermined coolant temperature is reached.
Abstract:
A fluidic self-actuating control assembly for use in a reactor wherein no external control inputs are required to actuate (scram) the system. The assembly is constructed to scram upon sensing either a sudden depressurization of reactor inlet flow or a sudden increase in core neutron flux. A fluidic control system senses abnormal flow or neutron flux transients and actuates the system, whereupon assembly coolant flow reverses, forcing absorber balls into the reactor core region.
Abstract:
An illustrative embodiment of the invention provides a control rod system locking device adapted to engage an elongated extension shaft, releasably coupled at one end to the control rod assembly and releasably coupled at its other end to the control rod drive, to prevent rotation of the shaft about its longitudinal axis with respect to the control rod assembly.
Abstract:
A snubber cartridge assembly is mounted to the nozzle of a control rod drive mechanism to insure that the snubber assembly will be located within the liquid filled section of a nuclear reactor vessel whenever the control rod drive is assembled thereto. The snubber assembly includes a piston mounted proximate to the control rod connecting end of the control rod drive leadscrew to allow the piston to travel within the liquid filled snubber cartridge and controllably exhaust liquid therefrom during a "scram" condition. The snubber cartridge provides three separate areas of increasing resistance to piston travel to insure a speedy but safe "scram" of the control rod into the reactor.
Abstract:
A method of operating a nuclear power reactor is disclosed which enables an accelerated power reduction of the reactor without completely shutting the reactor down. The method includes monitoring the incidents which, upon their occurrence, would require an accelerated power reduction in order to maintain the reactor in a safe operation mode; calculating the power reduction required on the occurrence of such an incident; determining a control rod insertion sequence for the normal operation of the reactor, said sequence being chosen to optimize reactor power capability; selecting the number of control rods necessary to respond to the accelerated power reduction demand, said selection being made according to a priority determined by said control rod insertion sequence; and inserting said selected control rods into the reactor core.
Abstract:
An improved core servicing apparatus for a nuclear reactor having a vessel, a head for the vessel, one or more penetration openings in the head and a core within the vessel of the type having an array of fuel assemblies and including apertures in the array for neutron absorbers. The servicing apparatus includes a support column adapted to be supported by and depend from the head in registry with a penetration opening; a plurality of core servicing elements which may include neutron absorber actuating means and/or instrument packages are supported by the support column; and means are provided for laterally displacing at least some of the servicing elements relative to the support column between a laterally compact and a laterally expanded configuration.In one embodiment, instruments may be located at the lower end of long resilient cables and are longitudinally movable within and beyond guide channels supported by the support column. The guide channels are directed outward at their lower ends to direct a descending instrument and cable outwardly.
Abstract:
A device for gripping bundles of control bars or rods for extracting the control bars from and introducing the control bars into fuel cells of nuclear reactors in which the control bars are in bundles connected by a spider-like head at the top and the gripping device includes a plate with a perforation through which the head can pass. When the head is released from the fuel cell and lifted upwardly through the plate, the plate provides lateral guidance for the control rods thereby facilitating replacement of the control rods into a fuel cell. The gripping device includes a reciprocable gripper body in a gripper tool detachably connectable thereto and to said head and guided on said plate by guide members projecting from the plate.