A nuclear reactor is designed to couple the load path of control elements with the reactor core, thus reducing opportunity for differential movement between the control elements and the reactor core. A core barrel can be fabricated in a manufacturing facility to include the reactor core, control element supports, and control element drive system. The core barrel can be mounted to a reactor vessel head. Movement, such as through seismic forces, transmits an equal direction and magnitude to the control elements and the reactor core, thus inhibiting the opportunity for differential movement.

A masking element with an opening is disposed on the side of a core support structure. A flow stack wall defines a plurality of inlets. At least one inlet aligns with the masking element opening when the flow stack is mated with the masking element. A flow control assembly within the flow stack is configured to restrict flow of fluid within the flow stack.

A masking element with an opening is disposed on the side of a core support structure. A flow stack wall defines a plurality of inlets. At least one inlet aligns with the masking element opening when the flow stack is mated with the masking element. A flow control assembly within the flow stack is configured to restrict flow of fluid within the flow stack.

A molten chloride fast reactor (MCFR) includes a plurality of reflectors defining a central core having a core geometric center. A flow channel fluidically connected to the central core. The flow channel includes an outlet flow channel downstream of the central core and an inlet flow channel upstream from the central core. A primary heat exchanger (PHX) disposed outside the central core and between the outlet flow channel and the inlet flow channel. The MCFR also includes a decay heat heat exchanger (DHHX). At least a portion of the DHHX is disposed above the core geometric center, and a fuel salt is configured to circulate at least partially through the outlet flow channel, the DHHX, the PHX, the inlet flow channel, and the central core.

A molten chloride fast reactor (MCFR) includes a plurality of reflectors defining a central core having a core geometric center. A flow channel fluidically connected to the central core. The flow channel includes an outlet flow channel downstream of the central core and an inlet flow channel upstream from the central core. A primary heat exchanger (PHX) disposed outside the central core and between the outlet flow channel and the inlet flow channel. The MCFR also includes a decay heat heat exchanger (DHHX). At least a portion of the DHHX is disposed above the core geometric center, and a fuel salt is configured to circulate at least partially through the outlet flow channel, the DHHX, the PHX, the inlet flow channel, and the central core.

A jet pump plug and methods of forming a seal with a plurality of nozzles of a jet pump are disclosed. The plug has a plug body and a washer embedded within and bonded to the plug body. The washer has a center opening that cooperates with the plug body to define a central bore extending through the plug and the central bore can be configured to receive a fastener. A plurality of the disclosed plugs can be positioned in alignment with a respective nozzle, with each plug being sealed to the respective nozzle to form a seal.

A jet pump plug and methods of forming a seal with a plurality of nozzles of a jet pump are disclosed. The plug has a plug body and a washer embedded within and bonded to the plug body. The washer has a center opening that cooperates with the plug body to define a central bore extending through the plug and the central bore can be configured to receive a fastener. A plurality of the disclosed plugs can be positioned in alignment with a respective nozzle, with each plug being sealed to the respective nozzle to form a seal.

A passively-cooled spent nuclear fuel pool system in one embodiment includes a containment vessel comprising a thermally conductive shell and an annular reservoir surrounding the shell that holds a liquid coolant forming a heat sink. A spent fuel pool is disposed inside the containment vessel and includes a body of water in contact with a first peripheral sidewall of the fuel pool. At least one spent nuclear fuel rod submerged in the body of water heats the water. The first peripheral sidewall of the spent fuel pool is formed by a portion of the shell of the containment vessel adjacent to the fuel pool, thereby defining a shared common heat transfer wall. The heat transfer wall operates to transfer heat from the body of water in the spent fuel pool to the heat sink to cool the body of water. The heat transfer wall comprises metal in one embodiment.

A passively-cooled spent nuclear fuel pool system in one embodiment includes a containment vessel comprising a thermally conductive shell and an annular reservoir surrounding the shell that holds a liquid coolant forming a heat sink. A spent fuel pool is disposed inside the containment vessel and includes a body of water in contact with a first peripheral sidewall of the fuel pool. At least one spent nuclear fuel rod submerged in the body of water heats the water. The first peripheral sidewall of the spent fuel pool is formed by a portion of the shell of the containment vessel adjacent to the fuel pool, thereby defining a shared common heat transfer wall. The heat transfer wall operates to transfer heat from the body of water in the spent fuel pool to the heat sink to cool the body of water. The heat transfer wall comprises metal in one embodiment.

A liquid metal-cooled nuclear reactor includes, within a reactor pressure vessel having a reactor core, a multistage annular linear induction pump (ALIP) configured to circulate liquid metal coolant through the reactor core. The multistage ALIP includes multiple sets of induction coils that at least partially define separate, respective stages of the multistage ALIP. The multiple sets of induction coils are configured to be electrically connected to separate, respective polyphase power supplies, such that the stages of the multistage ALIP are configured to be controlled independently of each other to adjustably control a flow of liquid metal coolant through the reactor core based on independent control of the multiple polyphase power supplies.