A feedwater sparger repair assembly includes a cover plate having a partial cylindrical shape and having a nozzle opening and a pair of bolt openings extending through the cover plate. A nozzle is attached to the cover plate and surrounds the nozzle opening. A pair of T-bolts extend through a respective one of the pair of bolt openings and each include a shank having a threaded portion extending from an exterior side of the cover plate and a partial cylindrical head portion disposed at an end of the shank on an interior side of the cover plate. A pair of nuts are engaged with the threaded portion of the pair of T-bolts. The feedwater sparger repair assembly is adapted to be mounted to an opening that is cut into a core spray pipe in order to repair/replace a sparger that becomes cracked.

A feedwater sparger repair assembly includes a cover plate having a partial cylindrical shape and having a nozzle opening and a pair of bolt openings extending through the cover plate. A nozzle is attached to the cover plate and surrounds the nozzle opening. A pair of T-bolts extend through a respective one of the pair of bolt openings and each include a shank having a threaded portion extending from an exterior side of the cover plate and a partial cylindrical head portion disposed at an end of the shank on an interior side of the cover plate. A pair of nuts are engaged with the threaded portion of the pair of T-bolts. The feedwater sparger repair assembly is adapted to be mounted to an opening that is cut into a core spray pipe in order to repair/replace a sparger that becomes cracked.

A nuclear fuel powder production plant comprises a conversion installation (2) for the conversion of uranium hexafluoride (UF.sub.6) into uranium dioxide (UO.sub.2) having a hydrolysis reactor (4) for the conversion of UF.sub.6 into uranium oxyfluoride powder (UO.sub.2F2) and a pyrohydrolysis furnace (6) for converting the UO.sub.2F2 powder into UO.sub.2 powder. The nuclear fuel powder production plant also includes a packaging unit (20) for the UO.sub.2 powder comprising a filling station (22) having a chamber (26) for receiving a container (24) to be filled, a filling duct (28) supplied from the furnace (6) and a suction system (32) comprising a suction ring (34) disposed at the outlet (30) of the filling duct (28) for sucking an annular air flow (A) around a stream (P) of UO.sub.2 powder falling from the outlet (30) from the filling duct (28) into the container (24).

A nuclear fuel powder production plant comprises a conversion installation (2) for the conversion of uranium hexafluoride (UF.sub.6) into uranium dioxide (UO.sub.2) having a hydrolysis reactor (4) for the conversion of UF.sub.6 into uranium oxyfluoride powder (UO.sub.2F2) and a pyrohydrolysis furnace (6) for converting the UO.sub.2F2 powder into UO.sub.2 powder. The nuclear fuel powder production plant also includes a packaging unit (20) for the UO.sub.2 powder comprising a filling station (22) having a chamber (26) for receiving a container (24) to be filled, a filling duct (28) supplied from the furnace (6) and a suction system (32) comprising a suction ring (34) disposed at the outlet (30) of the filling duct (28) for sucking an annular air flow (A) around a stream (P) of UO.sub.2 powder falling from the outlet (30) from the filling duct (28) into the container (24).

The present disclosure is directed to systems and methods useful for the construction and operation of a Modular Integrated Gas High-Temperature Reactor (MIGHTR). The MIGHTR includes a reactor core assembly disposed at least partially within a core baffle within a first high-pressure shell portion, a thermal transfer assembly disposed at least partially within a flow separation barrel within a second high-pressure shell portion. The longitudinal axes of the first high-pressure shell portion and the second high-pressure shell portion may be collinear. The reactor core assembly may be accessed horizontally for service, maintenance, and refueling. The core baffle may be flexibly displaceably coupled to the flow separation barrel. Coolant gas flows through the reactor core assembly and into the thermal transfer assembly where the temperature of the coolant gas is reduced. A plurality of coolant gas circulators circulate the cooled coolant gas from the thermal transfer assembly to the reactor core assembly.

The present disclosure is directed to systems and methods useful for the construction and operation of a Modular Integrated Gas High-Temperature Reactor (MIGHTR). The MIGHTR includes a reactor core assembly disposed at least partially within a core baffle within a first high-pressure shell portion, a thermal transfer assembly disposed at least partially within a flow separation barrel within a second high-pressure shell portion. The longitudinal axes of the first high-pressure shell portion and the second high-pressure shell portion may be collinear. The reactor core assembly may be accessed horizontally for service, maintenance, and refueling. The core baffle may be flexibly displaceably coupled to the flow separation barrel. Coolant gas flows through the reactor core assembly and into the thermal transfer assembly where the temperature of the coolant gas is reduced. A plurality of coolant gas circulators circulate the cooled coolant gas from the thermal transfer assembly to the reactor core assembly.

A pressurized water reactor (PWR) includes a vertical cylindrical pressure vessel having a lower portion containing a nuclear reactor core and a vessel head defining an integral pressurizer. A reactor coolant pump (RCP) mounted on the vessel head includes an impeller inside the pressure vessel, a pump motor outside the pressure vessel, and a vertical drive shaft connecting the motor and impeller. The drive shaft does not pass through the integral pressurizer. The drive shaft passes through a vessel penetration of the pressure vessel that is at least large enough for the impeller to pass through.

A pressurized water reactor (PWR) includes a vertical cylindrical pressure vessel having a lower portion containing a nuclear reactor core and a vessel head defining an integral pressurizer. A reactor coolant pump (RCP) mounted on the vessel head includes an impeller inside the pressure vessel, a pump motor outside the pressure vessel, and a vertical drive shaft connecting the motor and impeller. The drive shaft does not pass through the integral pressurizer. The drive shaft passes through a vessel penetration of the pressure vessel that is at least large enough for the impeller to pass through.

Fission reactor has a shell encompassing a reactor space within which are a central longitudinal channel, a plurality of axially extending rings with adjacent rings defining an annular cylindrical space in which a first plurality of primary axial tubes are circumferential located. Circumferentially adjacent primary axial tubes are separated by one of the plurality of secondary channels and a plurality of webbings connects at least a portion of the plurality of primary axial tubes to adjacent structure. A fissionable nuclear fuel composition is located in at least some of the plurality of secondary channels and a primary coolant passes thorough at least some of the primary axial tubes. Additive and/or subtractive manufacturing techniques produce an integral and unitary structure for the fuel loaded reactor space. During manufacturing and as-built, the reactor design can be analyzed using a computational platform that integrates and analyzes data from in-situ monitoring during manufacturing.

A tubular component for a pressurised-water nuclear reactor, has the following composition by weight: 0.8%≤Nb≤2.8%; traces≤Sn≤0.65%; 0.015%≤Fe≤0.40%; preferably 0.020%≤Fe≤0.35%; traces≤C≤100 ppm; 600 ppm≤O≤2300 ppm; preferably 900 ppm≤O≤1800 ppm; 5 ppm≤S≤100 ppm; preferably 8 ppm≤S≤35 ppm; traces≤Cr+V+Mo+Cu≤0.35%; traces≤Hf≤100 ppm; F≤1 ppm; the remainder being zirconium and impurities resulting from production. The tubular component has an outer surface with a roughness Ra less than or equal to 0.5 μm, obtained following a final mechanical polishing step. The outer surface has a roughness Rsk≤1 in absolute value and a roughness Rku≤10.