A control drum assembly may include a control drum and a control assembly coupled to the control drum through a drive shaft. The control drum assembly may also include a cage assembly. The cage assembly may include one or more structural supports and one or more modular platforms coupled to the one or more structural supports. The one or more modular platforms may be configured to support one or more components of the control assembly. The cage assembly may also include a base configured to be coupled to a surface of a core and to locate the cage assembly relative to the core.

A modular nuclear reactor system includes a lift-out, replaceable nuclear reactor core configured for replacement as a singular unit during a single lift-out event, such as rather than lifting and replacing individual fuel assemblies and/or fuel elements. The system includes a reactor vessel and a power generation system configured to convert thermal energy in a high temperature working fluid received from the reactor vessel into electrical energy. The reactor vessel includes: a vessel inlet and an adjacent vessel outlet arranged near a bottom on the vessel; a vessel receptacle configured to receive a unified core assembly; locating datums in the base of the vessel receptacle and configured to constrain a core assembly in multiple degrees of freedom; and an interstitial zone surrounding the vessel receptacle and housing a set of control or moderating drums.

An electromagnetic coil assembly for a control rod driving mechanism, comprising coils and a yoke for embedding the coils, wherein damascene holes are disposed on the yoke, the coils are installed in the damascene holes, the yoke comprises first yokes and second yokes, and the damascene holes are disposed on the first yokes; the first yokes are connected with the second yokes, and a through hole for cooperating with a sealing shell assembly is disposed on the second yokes; and a thermal conductivity of the first yokes is stronger than a thermal conductivity of the second yokes. The method is the processing method of the assembly. The coil assembly provided in technical solution or the coil assembly obtained by the method can remarkably reduce the temperature inside the coil, thereby improving the reliability of the CRDM electromagnetic coil assembly and prolonging the service life of the CRDM electromagnetic coil assembly.

An electromagnetic coil assembly for a control rod driving mechanism, comprising coils and a yoke for embedding the coils, wherein damascene holes are disposed on the yoke, the coils are installed in the damascene holes, the yoke comprises first yokes and second yokes, and the damascene holes are disposed on the first yokes; the first yokes are connected with the second yokes, and a through hole for cooperating with a sealing shell assembly is disposed on the second yokes; and a thermal conductivity of the first yokes is stronger than a thermal conductivity of the second yokes. The method is the processing method of the assembly. The coil assembly provided in technical solution or the coil assembly obtained by the method can remarkably reduce the temperature inside the coil, thereby improving the reliability of the CRDM electromagnetic coil assembly and prolonging the service life of the CRDM electromagnetic coil assembly.

Arrangements and devices for reducing and/or preventing wear of a thermal sleeve in a nuclear reactor are disclosed. Arrangements include a first structure provided on or in one the thermal sleeve and a second structure provided on or in the head penetration adapter. At least a portion of the first structure and at least another portion of the second structure interact to resist, reduce, and/or prevent rotation of the thermal sleeve about its central axis relative to the head penetration adapter. Devices include a base for coupling to a guide tube of the reactor and a plurality of protruding members extending upward from the base. Each member having a portion for engaging a corresponding portion of a guide funnel of the thermal sleeve.

A modular nuclear reactor system includes a lift-out, replaceable nuclear reactor core configured for replacement as a singular unit during a single lift-out event, such as rather than lifting and replacing individual fuel assemblies and/or fuel elements. The system includes a reactor vessel and a power generation system configured to convert thermal energy in a high temperature working fluid received from the reactor vessel into electrical energy. The reactor vessel includes: a vessel inlet and an adjacent vessel outlet arranged near a bottom on the vessel; a vessel receptacle configured to receive a unified core assembly; locating datums in the base of the vessel receptacle and configured to constrain a core assembly in multiple degrees of freedom; and an interstitial zone surrounding the vessel receptacle and housing a set of control or moderating drums.

A neutron moderator includes a porous metal hydride with channels within the porous metal hydride. Further, a method of regenerating a neutron moderator includes providing an at least partially depleted metal hydride article and introducing a hydrogen-containing gas into the at least partially depleted metal hydride article. The at least partially depleted metal hydride article includes channels. A nuclear reactor includes one or more neutron moderator regions in a core of a reactor, one or more fuel regions adjacent to the one or more neutron moderator regions, one or more heat transfer regions adjacent to the one or more fuel regions, control drums adjacent to the core, and a control rod adjacent to the core. One or more of the neutron moderator regions include a neutron moderator comprising a porous metal hydride article that has channels.

A neutron moderator includes a porous metal hydride with channels within the porous metal hydride. Further, a method of regenerating a neutron moderator includes providing an at least partially depleted metal hydride article and introducing a hydrogen-containing gas into the at least partially depleted metal hydride article. The at least partially depleted metal hydride article includes channels. A nuclear reactor includes one or more neutron moderator regions in a core of a reactor, one or more fuel regions adjacent to the one or more neutron moderator regions, one or more heat transfer regions adjacent to the one or more fuel regions, control drums adjacent to the core, and a control rod adjacent to the core. One or more of the neutron moderator regions include a neutron moderator comprising a porous metal hydride article that has channels.

Actuator of a nuclear reactor control and protection system comprises: a linear step motor comprising an armature; a rod being coaxial with and connected to the armature to enable joint vertical movement and rotation about a common vertical axis, which rod can form an L-shaped bayonet connection with a working member; and a lock to prevent spontaneous rotation of the rod. The lock comprises a guiding inside the armature and provided with a flange and longitudinal through slot; a cross-member connected to the armature, mounted in the slot and capable of vertical movement therein; a fixed ring, on which the inner surface of the flange rests; and a vertical pin. Through slots are arranged equidistantly in the outside rim of the flange, the vertical pin being mounted in one of several openings arranged equidistantly about the circumference of the fixed ring to pass through one of the through slots.

Detachable connection of a linear motor tubular armature and a vertical cylindrical rod of a nuclear reactor actuator, the rod, located in a guide pipe, is installed in the armature with an annular gap, in which a tubular fork with pins is placed. L-shaped slots are made at the end of the armature, vertical slots are made above them and the lower part of the armature is closed with a longitudinally fixed plug. On the side surface of the plug, -shaped grooves are made for the insertion or removal of the fork pins. Also, radial protrusions are made on the rod, and in the guide pipe, below the vertical slots of the armature, a bushing with -shaped grooves is fixed coaxially to the armature with the possibility of inserting the protrusions of the rod into, or removing the protrusions of the rod from, the grooves.