Westinghouse Electric Corporation

The United States of America as Represented by the United States

James D Mangus

John E Sharbaugh

Robert B Tupper

Julie M Livingston

Asfandiar K Dhalla

Gedney B Brown

Steven L Schrock

Martin H Cooper

A liquid metal nuclear reactor has a sodium tank, having a closed arcuate bottom and upstanding cylindrical wall for containing a reactor core in a pool of liquid metal coolant, which is disposed in a guard tank having a bottom and upwardly extending cylindrical shell, and a support inside the guard tank adjacent the closed bottom of the sodium tank to support the two tanks in spaced relationship to each other. Support legs are also provided about the bottom periphery of the guard tank adapted to rest on a base mat of a reactor cavity. The bottom of the guard tank may be a closed arcuate shape, or the bottom may be a flat bottom wall that rests on the base mat with the cylindrical shell divided into two radially spaced sections, with a pool of lead-bismuth alloy provided on the bottom to seal the spaces between the two shell sections at the lower region thereof. The pool of lead-bismuth alloy provided on the flat bottom wall of the guard tank contacts the bottom of the sodium tank to aid in preheating the same and providing a supporting and dampening effect therefor.

Bottom supported liquid metal nuclear reactor

A liquid metal nuclear reactor has a sodium tank, having a closed arcuate bottom and upstanding cylindrical wall for containing a reactor core in a pool of liquid metal coolant, which is disposed in a guard tank having a bottom and upwardly extending cylindrical shell, and a support inside the guard tank adjacent the closed bottom of the sodium tank to support the two tanks in spaced relationship to each other. The sodium tank has an open top spaced from an overlying closure deck, with the cylindrical shell of the guard tank secured to the closure deck. The support is preferably an inner ledge. Support legs are also provided about the bottom periphery of the guard tank adapted to rest on a base mat of a reactor cavity. The bottom of the guard tank may be a closed arcuate shape, or the bottom may be a flat bottom wall that rests on the base mat with the cylindrical shell divided into two radially spaced sections, with a pool of lead-bismuth alloy provided on the bottom to seal the spaces between the two shell sections at the lower region thereof. A metal barrier may be provided between the guard tank and the reactor cavity side wall to divide the area therebetween into two annular chambers, with a thermal insulation provided on the barrier outside to form the inner chamber into an oven-like chamber.

The nuclear reactor shutdown system comprises a temperature sensitive device connected to a magnetic latch of a neutron absorbing mechanism. The temperature sensitive device is disposed in the neutron absorbing mechanism in such a manner that it is exposed to the reactor coolant so that when the reactor coolant temperature rises above a specific level, the temperature sensitive device will cause the magnetic latch to open and allow neutron absorbing material to enter the reactor core. The temperature sensitive device comprises temperature sensitive material which may be a temperature sensitive resistor sometimes referred to as a thermistor. The thermistor is a device wherein its resistivity significantly increases with increase in its temperature such that when its temperature has significantly increased, the current passing through this system substantially decreases. Therefore, when the nuclear reactor coolant temperature rises significantly, the resistivity in the temperature sensitive material significantly increases to the point where little electricity flows through the circuit thereby causing the magnetic field in the magnetic latch to fall to a level at which the magnetic latch opens thereby inserting neutron absorbing material in the reactor core.

Nuclear reactor shutdown system

A steam cycle for a nuclear power plant having two optional modes of operation. A once-through mode of operation uses direct feed of coolant water to an evaporator avoiding excessive chemical concentration buildup. A recirculation mode of operation uses a recirculation loop to direct a portion of flow from the evaporator back through the evaporator to effectively increase evaporator flow.

Low chemical concentrating steam generating cycle

A fluid circulation system for heat exchangers having two groups of tubes through which primary and secondary fluids flow, the tubes of one group being interdigitated with the tubes of the other group, and a heat transfer material interposed between the two groups of tubes, whereby heat is transferred from the primary fluid through the heat transfer material to the secondary fluid. A shell forms a closure around the tubes and the heat transfer material, and the shell has tertiary fluid inlet and outlet means. Openings in the heat transfer material form passageways through which the tertiary fluid can flow from the inlet means, through the heat exchanger, to the outlet means. Piping connects the tertiary fluid outlet means to the tertiary fluid inlet means, forming a complete cycle. Installed in this piping is a heat removal system. If the secondary fluid flow is interrupted, the tertiary fluid provides a redundant means by which the heat of the primary fluid can be removed from the heat exchanger. Monitoring means can be inserted into the piping, to detect any leakages which may occur in the primary and secondary tubes. Condensers or desiccating material can be installed in the heat removal means to remove any liquids which may leak into the tertiary fluid. Additionally, if the tertiary fluid is a gas or vapor, a turbine can be inserted into the piping and the tertiary fluid's power utilized to provide energy to power the compressor or pump which is circulating the tertiary fluid. In an emergency, this turbine can be connected to an electrical generator and provide emergency power to the rest of the plant.

Fluid circulation system for heat exchangers

A system for transporting reactor coolant in nuclear reactors using a liquid coolant. The system diverts a portion of the output from the main circulating pump in the nuclear reactor primary flow system and introduces this diverted coolant back into the system upstream of the main circulating pump. This diverted coolant compensates for any pressure drop which may occur due to the pumping action, thereby maintaining a constant head to the circulating pump.

Nuclear reactor coolant transport system

A method and apparatus for detecting a specific leaking tube or tubes and for detecting the position of a defect within a tube in a liquid metal-to-water tube type heat exchanger, generally used in a sodium cooled nuclear reactor. Subsequent to draining of the heat exchanger a solid reaction product of the liquid metal and water forms at a leak location. Introducing an inert gas to the exterior of the tubes, creating a pressure differential across the tube wherein the interior pressure is less than the exterior pressure, and heating the tube, provide dissociation and isolation of the reaction product, which, when analyzed for chemical content, indicates which tube or tubes is defective. A heat probe apparatus which traverses the interior of the tubes may be used in the heating step, which, as a result of the speed of the dissociation process at high temperatures provides a means for detecting the specific leak location within the tube. A heat apparatus which traverses the exterior of bayonet type tubes may be used in another embodiment.

Method and apparatus for locating a defective tube of a liquid

A method and apparatus for power generation from a recirculating superheat-reheat circuit with multiple expansion stages which alleviates complex control systems and minimizes thermal cycling of system components, particularly the reheater. The invention includes preheating cold reheat fluid from the first expansion stage prior to its entering the reheater with fluid from the evaporator or drum component.

Method and apparatus for thermal power generation

Apparatus as disclosed for eliminating drawdown of the level of liquid in a sump suction type of pump having a cover gas above the liquid therein. The liquid level is maintained throughout all pump operating speeds and without the need to vary the cover gas pressure of the pump. The pump includes a divider plate which separates the sump tank into upper and lower chambers. When the speed of the pump increases, the divider plate serves to limit the amount of liquid flowing therepast. An orifice flow tube connects the pump outlet to the upper chamber of the sump tank. Thus, the leakage flow past the divider plate is pumped back into the upper chamber thereby automatically compensating for the effect of pump drawdown.

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Hempfield Township, PA, United States of America

James D Mangus