Provided is an apparatus for generating electricity, mechanical energy, and/or process and district heat using a gas propellant chamber fueled with fissile material and enclosed in a sealed containment vessel which also contains an operating gas. The system allows for the operating gas to be compressed as it enters the nuclear fuel chamber where it is heated. As the operating gas exits the nuclear fuel chamber, the kinetic energy of the gas is converted to rotational energy by a variety of methods. The rotational energy is further converted to electricity, mechanical energy, and/or process and district heat. The operating gas circulates in the containment vessel and is cooled prior to re-entering the gas propellant chamber. The apparatus thereby provides a simpler and safer design that is both scalable and adaptable. The apparatus is easily and safely transportable and can be designed to be highly nuclear-proliferation-resistant.

A fusion drive magnetically confining a plasma in a stable plectonemic minimum-energy Taylor states formed from the merging of a plurality of plectonemic Taylor states. Magnetic reconnection converts magnetic energy into ion heating to attain high temperatures before compression. The plasma configuration is then compressed to net gain in a peristaltic magnetic nozzle arrangement. The fusion drive supports generation of electrical power with inductive direct electric or thermal conversion methods.

To reduce size and mass of a nuclear reactor system, an integrated in-vessel shield separates the role of a neutron reflector and a neutron shield. Nuclear reactor system includes a pressure vessel including an interior wall and a nuclear reactor core located within the interior wall of the pressure vessel. Nuclear reactor core includes a plurality of fuel elements and at least one moderator element. Nuclear reactor system includes a reflector located inside the pressure vessel that includes a plurality of reflector blocks laterally surrounding the plurality of fuel elements and the at least one moderator element. Nuclear reactor system includes the in-vessel shield located on the interior wall of the pressure vessel to surround the reflector blocks. In-vessel shield is formed of two or more neutron absorbing materials. The two more neutron absorbing materials include a near black neutron absorbing material and a gray neutron absorbing material.

A control rod assembly for a nuclear reactor having a reactor core and a pressurized fluid source, including a control rod disposed within a control rod sleeve, a lead screw that is selectively secured to the control rod, a trip latch that is secured to a bottom end of the lead screw, the trip latch being selectively securable to a top end of the control rod, a control rod drive motor that is operably connected to the lead screw, and a valve that is in fluid communication with the pressurized fluid source of the nuclear reactor and is movable between a first position and a second position, wherein in the second position of the gas valve the trip latch is in an open position.

A reactor core block is disclosed including a fuel channel, a heat pipe, a primary moderator matrix configured to encompass the fuel channel and the heat pipe, and a secondary moderator channel configured to at least partially surround the fuel channel, the heat pipe, and the primary moderator matrix. The secondary moderator channel is comprised of metal hydride.

A reactor core block is disclosed including a fuel channel, a heat pipe, a primary moderator matrix configured to encompass the fuel channel and the heat pipe, and a secondary moderator channel configured to at least partially surround the fuel channel, the heat pipe, and the primary moderator matrix. The secondary moderator channel is comprised of metal hydride.

A method for generating a fissile material is described. The method includes positioning a fertile, non-fissile material within outer space, the position within an area of proton or other high energy particle radiation, rather naturally or artificially occurring, allowing the high energy particle radiation to impinge the fertile but non-fissile material over a time, the time based on amount of high energy particle radiation at the position, such that the non-fissile material gradually transmutes into a fissile material due to the impingement, and deploying the fissile material within a spacecraft.

A passive waste heat removal system on the secondary side of a marine environmental reactor. The system includes a containment, an airtight water tank, and a steam generator. The containment is partially or fully immersed in seawater. The airtight water tank is disposed on the inner wall surface of the containment, the airtight water tank being provided with a water tank inlet and a water tank outlet. The steam generator is placed in the containment, the steam generator having a steam outlet and a feedwater inlet. The water tank inlet of the airtight water tank communicates with the steam outlet of the steam generator by means of a first pipe, and the water tank outlet of the airtight water tank communicates with the feedwater inlet of the steam generator by means of a second pipe.

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.