A power distribution plate (PDP) sits on top of a support plate. Control rod drive mechanism (CRDM) units are mounted on top of the PDP, but the PDP is incapable of supporting the weight of the CRDM units and instead transfers the load to a support plate. The PDP has receptacles which receive cable modules each including mineral insulated (MI) cables, the MI cables being connected with the CRDM units. The PDP may further include a set of hydraulic lines underlying the cable modules and connected with the CRDM units. The cable modules in their receptacles define conduits or raceways for their MI cables and for any underlying hydraulic lines.

A power distribution plate (PDP) sits on top of a support plate. Control rod drive mechanism (CRDM) units are mounted on top of the PDP, but the PDP is incapable of supporting the weight of the CRDM units and instead transfers the load to a support plate. The PDP has receptacles which receive cable modules each including mineral insulated (MI) cables, the MI cables being connected with the CRDM units. The PDP may further include a set of hydraulic lines underlying the cable modules and connected with the CRDM units. The cable modules in their receptacles define conduits or raceways for their MI cables and for any underlying hydraulic lines.

A Control Neutron Absorber (CNA) assembly for a microreactor that produces nuclear energy is disclosed. The CNA assembly includes a housing, a CNA rod, and a burnable absorber. The housing includes an inner housing and an outer housing. The inner housing is configured to receive a CNA rod. The outer housing extends coaxially with the inner housing and is positioned radially outward and offset from the inner housing defining a cavity therebetween. The CNA rod includes a neutron absorbing rod including a first neutron absorbing material. The neutron absorbing rod is positioned within the inner housing and is configured to move axially relative to the inner housing. The burnable absorber includes a second neutron absorbing material, exhibits a neutron absorbing strength that is less than that of the neutron absorbing rod, is positioned within the inner housing, and is configured to receive the neutron absorbing rod therein.

A vessel electrical penetration assembly for a feed-through of nuclear reactor vessel, the assembly including: a docking tube to form an extension of the secondary containment barrier of the reactor, the docking tube including: a first end to be positioned in the interior of the vessel and to be mechanically and sealably connected to an actuator in the interior of the vessel, and a second end to be mechanically and sealably secured to the vessel; a seal-tight electrical bar that passes through the docking tube and having on either side seal-tight connectors ensuring an electrical link between the actuator and the exterior of the reactor; the seal-tight electrical bar including a system for limiting a leakage of primary liquid to the exterior of the vessel if the secondary containment barrier extension fails; and a mechanical maintaining system for securing, under the required pressure conditions, the electrical bar to the vessel.

A vessel electrical penetration assembly for a feed-through of nuclear reactor vessel, the assembly including: a docking tube to form an extension of the secondary containment barrier of the reactor, the docking tube including: a first end to be positioned in the interior of the vessel and to be mechanically and sealably connected to an actuator in the interior of the vessel, and a second end to be mechanically and sealably secured to the vessel; a seal-tight electrical bar that passes through the docking tube and having on either side seal-tight connectors ensuring an electrical link between the actuator and the exterior of the reactor; the seal-tight electrical bar including a system for limiting a leakage of primary liquid to the exterior of the vessel if the secondary containment barrier extension fails; and a mechanical maintaining system for securing, under the required pressure conditions, the electrical bar to the vessel.

A decommissioning method of biological shielding concrete of a nuclear power plant according to an exemplary embodiment includes: decommissioning a neutron detector positioning device installed to biological shielding concrete surrounding a nuclear reactor to form a plurality of penetrated parts in the biological shielding concrete; inserting a part of a cutting device into the plurality of penetrated parts; and decomposing the biological shielding concrete into a plurality of sub-concrete parts by using the cutting device.

A feedthrough includes: a main body having at least one passage opening that extends through the main body; at least one first functional element which is disposed within the at least one passage opening and is connected to the main body in a fluid-tight manner; and an insulation material that surrounds at least some regions of the at least one first functional element and establishes the fluid-tight connection to the main body. Within the at least one first functional element, there is a pressure-guiding channel by which pressure components that have arisen as a result of pressure are guided from within the at least one first functional element outward to the surrounding insulation material such that a pressure resistance of the fluid-tight connection of the at least one first functional element to the main body is elevated.

An apparatus having a nuclear reactor comprising a pressure vessel containing primary coolant water and further containing a nuclear reactor core comprising fissile material, a mounting/electrical distribution plate secured entirely within the pressure vessel and configured to be submerged in the primary coolant, a set of control rod drive mechanism (CRDM) units mounted directly on the mounting/electrical distribution plate, and a plurality of cable modules mounted in receptacles of the mounting/electrical distribution plate wherein each cable module includes mineral insulated (MI) cables connected with one or more of the CRDM units, the cable module including its MI cables being removable as a unit from the receptacle of the mounting/electrical distribution plate.

An apparatus having a nuclear reactor comprising a pressure vessel containing primary coolant water and further containing a nuclear reactor core comprising fissile material, a mounting/electrical distribution plate secured entirely within the pressure vessel and configured to be submerged in the primary coolant, a set of control rod drive mechanism (CRDM) units mounted directly on the mounting/electrical distribution plate, and a plurality of cable modules mounted in receptacles of the mounting/electrical distribution plate wherein each cable module includes mineral insulated (MI) cables connected with one or more of the CRDM units, the cable module including its MI cables being removable as a unit from the receptacle of the mounting/electrical distribution plate.

A vessel electrical penetration assembly for a feed-through of nuclear reactor vessel, the assembly including: a docking tube to form an extension of the secondary containment barrier of the reactor, the docking tube including: a first end to be positioned in the interior of the vessel and to be mechanically and sealably connected to an actuator in the interior of the vessel, and a second end to be mechanically and sealably secured to the vessel; a seal-tight electrical bar that passes through the docking tube and having on either side seal-tight connectors ensuring an electrical link between the actuator and the exterior of the reactor; the seal-tight electrical bar including a system for limiting a leakage of primary liquid to the exterior of the vessel if the secondary containment barrier extension fails; and a mechanical maintaining system for securing, under the required pressure conditions, the electrical bar to the vessel.