US 12,410,766 B1
Radial in-flow particle bed nuclear rocket engine and method
Gregory George Loboda, Huntington Beach, CA (US); Fred George William Kennedy, III, Hillsboro, VA (US); and Michael Gordon Jacox, Magnolia, TX (US)
Assigned to Dark Fission Space Systems Inc., Huntington Beach, CA (US)
Filed by Dark Fission Space Systems Inc., Huntington Beach, CA (US)
Filed on Aug. 14, 2023, as Appl. No. 18/233,554.
Claims priority of provisional application 63/371,492, filed on Aug. 15, 2022.
Int. Cl. G21D 5/02 (2006.01); B64G 1/40 (2006.01); B64G 1/42 (2006.01); F02K 9/64 (2006.01); G21C 7/28 (2006.01); G21C 15/06 (2006.01); G21C 15/08 (2006.01); G21C 15/10 (2006.01); G21C 1/06 (2006.01)
CPC F02K 9/64 (2013.01) [B64G 1/408 (2013.01); B64G 1/422 (2013.01); G21C 7/28 (2013.01); G21C 15/06 (2013.01); G21C 15/08 (2013.01); G21C 15/10 (2013.01); G21D 5/02 (2013.01); F05D 2260/20 (2013.01); G21C 1/06 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a pump configured to pump a propellant;
a set of fuel elements, each fuel element of the set of fuel elements comprising:
a set of low enriched uranium fuel particles defining a set of interstitial volumes through which the pump pumps the propellant;
a moderator:
defining a set of fuel bores, each fuel bore in the set of fuel bores:
fluidly coupled to a warm propellant inflow manifold;
occupied by a fuel element; and
configured to direct warm propellant axially downward from the warm propellant inflow manifold along a length of the fuel element; and
defining a set of moderator coolant channels, each moderator coolant channel:
fluidly isolated from the set of fuel bores;
defining a set of moderator coolant inlets fluidly coupled to a thrust-coolant valve;
defining a set of moderator coolant outlets fluidly coupled to a pump bypass valve; and
configured to pass propellant through the moderator to cool the moderator;
a reflector arranged on a perimeter of the moderator:
comprising:
a neutron-reflecting material; and
a reflector coolant channel arranged within the reflector and configured to exchange thermal energy with propellant pumped through the reflector coolant channel;
operable in:
a first position, the reflector defining a first cross-section of the neutron-reflecting material facing the set of fuel elements in the first position and reflecting incident neutrons toward the set of fuel elements at a first rate;
a second position, the reflector defining a second cross-section of the neutron-reflecting material facing the set of fuel elements in the second position and reflecting incident neutrons toward the set of fuel elements at a second rate, the second cross-section less than the first cross-section, the second rate less than the first rate; and
a thrust nozzle configured to outlet propellant to produce thrust; and
comprising a nozzle coolant channel arranged within a wall of the thrust nozzle and configured to exchange thermal energy with propellant pumped through the nozzle coolant channel.