Combustion Engineering, Inc.

Richard C Noyes

Shakir U Zaman

Clive Frederick Dupen

Nicholas Giuggio

Edward A Siegel

Christo Andrea

Donald Martin Barrus

Douglas W Stuteville

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.

Temperature sensitive self-actuated scram mechanism

A poison bundle release mechanism within a safety assembly of a liquid metal nuclear reactor. A baffle consisting of a plate with recesses in fluid communication with low pressure coolant is formed in the upper portion of the safety assembly. A plug attached to the upper end of the poison bundle fits snugly against the recesses and is held up against the plate by the coolant pressure difference acting on the lower and upper sides of the plug. A conduit and valve arrangement is provided within the plug whereby the actuation of the valve permits high pressure coolant to enter the recessed region, reducing the pressure difference across the plug and producing rapid disengagement thereof from the plate.

Hydraulic latch scram release mechanism

A sensor chamber having one cavity containing coolant separated by a diaphragm from another cavity containing a fixed mass of inert gas is located within a safety assembly of a liquid metal-cooled nuclear reactor. The liquid cavity is in fluid communication with the coolant outside the chamber through a flow limiting orifice. An actuating bellows in fluid communication with the gas cavity is in contact with coolant outside the chamber and is connected to a push rod, which serves as a trigger for a poison bundle release mechanism. During slow changes in reactor coolant pressure experienced under normal operation, the diaphragm moves to equalize the gas cavity and liquid cavity pressures with the coolant pressure outside the chamber. The actuating bellows does not move because it is biased so that a threshold pressure difference is required before it will expand. Under a more rapid drop in coolant pressure, such as is associated with a loss of forced flow, the threshold is overcome and the actuating bellows will also move, thereby triggering the release mechanism to shut down the reactor. In an alternate embodiment, the actuating bellows is connected to the liquid cavity rather than to the gas cavity.

Self-actuated rate of change of pressure scram device for nuclear

An apparatus for holding, releasing, and resetting a multiplicity of neutron absorbing balls within a safety assembly of a liquid metal nuclear reactor comprising vertically hinged trap doors resting on the shoulders of a generally cylindrical release valve, the actuation of which disengages the doors, permitting the poison balls above the doors to drop into the core. In the reset mode of operation a platform is raised, lifting the balls from the bottom of the core and swinging the trap doors upward until the balls are above the door hinges. The release valve is reset and the platform is lowered to reset the doors against the valve shoulders. In the disclosed embodiment, the valve is operated by a self-actuated, temperature responsive scram mechanism.

Scram device having a multiplicity of neutron absorbing masses

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.

Control rod and/or instrument tree assembly

A fuel handling machine for a liquid metal cooled nuclear reactor in which a retractable handling tube and gripper are lowered into the reactor to withdraw a spent fuel assembly into the handling tube. The handling tube containing the fuel assembly immersed in liquid sodium is then withdrawn completely from the reactor into the outer barrel of the handling machine. The machine is then used to transport the spent fuel assembly directly to a remotely located decay tank. The fuel handling machine includes a decay heat removal system which continuously removes heat from the interior of the handling tube and which is capable of operating at its full cooling capacity at all times. The handling tube is supported in the machine from an articulated joint which enables it to readily align itself with the correct position in the core. An emergency sodium supply is carried directly by the machine to provide make up in the event of a loss of sodium from the handling tube during transport to the decay tank.

Growing community of inventors

New Britain, CT, United States of America

Richard C Noyes