Nuclear reactor system arranged to inject material into heat pipes to suppress a fire
A system for mitigating and/or preventing potential fire hazards in a nuclear reactor including a heat pipe reactor core is provided. The system further comprises a plurality of heat pipes, the heat pipe reactor core engaging the plurality of heat pipes between first and second ends of each respective heat pipe. A heat exchanger device defining an enclosed gas chamber annularly surrounds at least a portion of at least one heat pipe. The system further comprises a first valve and a second valve positioned proximate the first end of the at least one heat pipe, the first valve fluidly coupling the at least one heat pipe to a first suppressant chamber and the second valve fluidly coupling the enclosed gas chamber to a second suppressant chamber. Each of the first and second valves is movable between open and closed positions to regulate the flow of fire suppressant material from the first and second suppressant chambers, respectively.
1 . A system comprising:
a nuclear reactor comprising a heat pipe reactor core;
a plurality of heat pipes, wherein each respective heat pipe comprises an elongated body defining a first end of the respective heat pipe and a second end opposite the first end and an interior cavity therebetween, and wherein the first end and the second end of each respective heat pipe are positioned externally of the heat pipe reactor core such that the heat pipe reactor core engages the plurality of heat pipes between the first end and the second end of the respective heat pipe;
a heat exchanger device, the heat exchanger device defining an enclosed gas chamber annularly surrounding at least a portion of at least one heat pipe, the enclosed gas chamber comprising an inert gas; and
a first suppressant chamber and a second suppressant chamber, each suppressant chamber containing a fire suppressant material,
wherein a first valve is positioned proximate the first end of at least one heat pipe of the plurality of heat pipes, the first valve fluidly coupling the at least one heat pipe to the first suppressant chamber,
wherein the first valve is movable between open and closed positions to regulate a flow of the fire suppressant material from the first suppressant chamber into the interior cavity of the at least one heat pipe,
wherein a second valve is positioned proximate the first end of the at least one heat pipe of the plurality of heat pipes, the second valve fluidly coupling the enclosed gas chamber to the second suppressant chamber, and
wherein the second valve is movable between open and closed positions to regulate the flow of the fire suppressant material from the second suppressant chamber into the enclosed gas chamber.
2 . The system of claim 1 , wherein the fire suppressant material comprises boron.
3 . The system of claim 1 , wherein the nuclear reactor is a molten-salt cooled reactor and further comprises an auxiliary pump configured to pump molten salt through a molten-salt cooled reactor core and the at least one heat pipe is configured to assist in regulating a temperature of the auxiliary pump.
4 . The system of claim 1 , the system further comprising:
at least one sensor; and
a controller communicably coupled with the at least one sensor, the controller configured to:
receive sensed temperature data from the at least one sensor, the sensed temperature data indicative of a temperature of at least a portion of the system;
determine whether the sensed temperature data satisfies a first predefined threshold; and
in response to determining that the sensed temperature data satisfies the first predefined threshold, activate the first valve such that the first valve is in the open position and the flow of the fire suppressant material from the first suppressant chamber is injected into the interior cavity of the at least one heat pipe.
5 . The system of claim 4 , wherein the at least one sensor is located proximate an exit of the heat pipe reactor core.
6 . The system of claim 4 , wherein the system further comprises: a third suppressant chamber,
wherein a third valve is positioned proximate the second end of at least one heat pipe of the plurality of heat pipes, the third valve fluidly coupling the at least one heat pipe of the plurality of heat pipes to the third suppressant chamber, and
wherein the third valve is movable between open and closed positions to regulate a flow of fire suppressant material from the third suppressant chamber into the interior cavity of the at least one heat pipe or regulate a flow of working fluid from the interior cavity into the third suppressant chamber.
7 . The system of claim 6 , wherein the third suppressant chamber contains the fire suppressant material, and wherein the controller is further configured to:
determine whether the sensed temperature data satisfies a second predefined threshold; and
in response to determining that the sensed temperature data satisfies the second predefined threshold, activate the first valve and the third valve such that each of the first and third valves is in the open position and the flows of the fire suppressant material are simultaneously injected into the interior cavity of the at least one heat pipe via the first and second ends of the at least one heat pipe.
8 . The system of claim 6 , wherein the controller is further configured to:
determine whether the sensed temperature data satisfies a second predefined threshold; and
in response to determining that the sensed temperature data satisfies the second predefined threshold, activate the third valve such that the third valve is in the open position to evacuate at least a portion of a working fluid from the interior cavity of the at least one heat pipe through the third valve.
9 . The system of claim 8 , wherein the evacuation of the at least a portion of the working fluid through the third valve is configured to occur simultaneously with the injection of the fire suppressant material from the first suppressant chamber into the interior cavity of the at least one heat pipe via the first valve.
10 . The system of claim 8 , wherein the controller is configured to activate the third valve such that the third valve is in the open position to evacuate the at least a portion of the working fluid through the third valve prior to activating the first valve to inject the fire suppressant material from the first suppressant chamber into the interior cavity of the at least one heat pipe via the first valve.
11 . The system of claim 10 , wherein the controller is further configured to:
subsequent to activating the first valve, activate the second valve such that the second valve is in the open position and the flow of the fire suppressant material from the second suppressant chamber is injected into the enclosed gas chamber.
12 . The system of claim 6 , wherein the system further comprises:
a fourth suppressant chamber,
wherein a fourth valve is positioned proximate the second end of the at least one heat pipe of the plurality of heat pipes, the fourth valve fluidly coupling the enclosed gas chamber to the fourth suppressant chamber, and
wherein the fourth valve is movable between open and closed positions to regulate a flow path from the fourth suppressant chamber into the enclosed gas chamber.
13 . The system of claim 1 , wherein the heat exchanger device comprises a layer of phase change material disposed on an outer surface of the enclosed gas chamber.
14 . The system of claim 13 , wherein the phase change material is a salt.
15 . The system of claim 13 , wherein the phase change material is an alkali metal fire retardant.
16 . The system of claim 13 , wherein the layer of phase change material is partitioned by one or more partition components, the one or more partition components extending from the outer surface of the enclosed gas chamber, through the layer of phase change material, to an outer surface of the layer of phase change material.
17 . The system of claim 16 , wherein the heat exchanger device comprises at least one heat dissipating surface disposed on the outer surface of the layer of phase change material, the at least one heat dissipating surface comprising one or more fin components.
18 . The system of claim 1 , wherein the heat pipe reactor core further comprises a plurality of gaps between a plurality of fuel rods and the plurality of heat pipes, and wherein a neutron absorber material is disposed in the plurality of gaps.
19 . The system of claim 18 , wherein the neutron absorber material comprises cadmium.
20 . The system of claim 1 , wherein the fire suppressant material in the second suppressant chamber differs from the fire suppressant material in the first suppressant chamber.