A neutron detector is disclosed herein. The neutron detector can include a housing defining a cavity, wherein the housing is configured to permit an amount of neutrons emitted from a core of a nuclear reactor to enter the cavity. The neutron detector can also include an amount of a neutron sensitive material dispositioned within the cavity, wherein the neutron sensitive material is configured to generate and emit gamma rays upon interacting with the amount of neutrons. The neutron detector can further include an amount of electron emissive material configured to generate and emit a current of electrons upon interacting with the emitted gamma rays, wherein the current of electrons is indicative of the amount of neutrons emitted from the core of the nuclear reactor.

A hybrid nuclear reactor that is operable to produce a medical isotope includes an ion source operable to produce an ion beam from a gas, a target chamber including a target that interacts with the ion beam to produce neutrons, and an activation cell positioned proximate the target chamber and including a parent material that interacts with the neutrons to produce the medical isotope via a fission reaction. An attenuator is positioned proximate the activation cell and selected to maintain the fission reaction at a subcritical level, a reflector is positioned proximate the target chamber and selected to reflect neutrons toward the activation cell, and a moderator substantially surrounds the activation cell, the attenuator, and the reflector.

A hybrid nuclear reactor that is operable to produce a medical isotope includes an ion source operable to produce an ion beam from a gas, a target chamber including a target that interacts with the ion beam to produce neutrons, and an activation cell positioned proximate the target chamber and including a parent material that interacts with the neutrons to produce the medical isotope via a fission reaction. An attenuator is positioned proximate the activation cell and selected to maintain the fission reaction at a subcritical level, a reflector is positioned proximate the target chamber and selected to reflect neutrons toward the activation cell, and a moderator substantially surrounds the activation cell, the attenuator, and the reflector.

A target irradiation system for irradiating a radioisotope target in a vessel penetration of a fission reactor, includes a target delivery assembly with a body defining a central bore, a basket that is slidably receivable within the central bore of the body, and a winch that is connected to the basket by a cable. The target delivery assembly is affixed to the vessel penetration of the reactor; and a target passage is in fluid communication with the target delivery assembly. The basket is configured to receive a radioisotope target therein via the target passage and be lowered into the vessel penetration of the reactor when irradiating the radioisotope target. The target delivery system forms a portion of the pressure boundary of the reactor when in fluid communication with the reactor.

A hybrid nuclear reactor that is operable to produce a medical isotope includes an ion source operable to produce an ion beam from a gas, a target chamber including a target that interacts with the ion beam to produce neutrons, and an activation cell positioned proximate the target chamber and including a parent material that interacts with the neutrons to produce the medical isotope via a fission reaction. An attenuator is positioned proximate the activation cell and selected to maintain the fission reaction at a subcritical level, a reflector is positioned proximate the target chamber and selected to reflect neutrons toward the activation cell, and a moderator substantially surrounds the activation cell, the attenuator, and the reflector.

A hybrid nuclear reactor that is operable to produce a medical isotope includes an ion source operable to produce an ion beam from a gas, a target chamber including a target that interacts with the ion beam to produce neutrons, and an activation cell positioned proximate the target chamber and including a parent material that interacts with the neutrons to produce the medical isotope via a fission reaction. An attenuator is positioned proximate the activation cell and selected to maintain the fission reaction at a subcritical level, a reflector is positioned proximate the target chamber and selected to reflect neutrons toward the activation cell, and a moderator substantially surrounds the activation cell, the attenuator, and the reflector.

An aqueous assembly has a negative coefficient of reactivity with a magnitude. The aqueous assembly includes a vessel and an aqueous solution, with a fissile solute, supported in the vessel. A reactivity stabilizer is disposed within the aqueous solution to reduce the magnitude of the negative coefficient of reactivity of the aqueous assembly during operation of the aqueous assembly.

An aqueous assembly has a negative coefficient of reactivity with a magnitude. The aqueous assembly includes a vessel and an aqueous solution, with a fissile solute, supported in the vessel. A reactivity stabilizer is disposed within the aqueous solution to reduce the magnitude of the negative coefficient of reactivity of the aqueous assembly during operation of the aqueous assembly.

A neutron detector is disclosed herein. The neutron detector can include a housing defining a cavity, wherein the housing is configured to permit an amount of neutrons emitted from a core of a nuclear reactor to enter the cavity. The neutron detector can also include an amount of a neutron sensitive material dispositioned within the cavity, wherein the neutron sensitive material is configured to generate and emit gamma rays upon interacting with the amount of neutrons. The neutron detector can further include an amount of electron emissive material configured to generate and emit a current of electrons upon interacting with the emitted gamma rays, wherein the current of electrons is indicative of the amount of neutrons emitted from the core of the nuclear reactor.

A neutron detector is disclosed herein. The neutron detector can include a housing defining a cavity, wherein the housing is configured to permit an amount of neutrons emitted from a core of a nuclear reactor to enter the cavity. The neutron detector can also include an amount of a neutron sensitive material dispositioned within the cavity, wherein the neutron sensitive material is configured to generate and emit gamma rays upon interacting with the amount of neutrons. The neutron detector can further include an amount of electron emissive material configured to generate and emit a current of electrons upon interacting with the emitted gamma rays, wherein the current of electrons is indicative of the amount of neutrons emitted from the core of the nuclear reactor.