A nuclear reactor scram control system for a nuclear reactor includes a solenoid pilot valve (SSPV). The SSPV includes a solenoid indicator light electrically coupled to an SSPV solenoid of the SSPV. The solenoid indicator light may be selectively activated based on an energization state of the SSPV solenoid, thereby providing an immediate and visually observable indication of the SSPV energization state. The immediate and visually observable indication of the SSPV energization state may enable quicker and more reliable verification of SSPV solenoid energization state. As a result, operator radiation exposure associated with verification may be reduced, and a risk of inadvertent nuclear reactor scram based on a de-energized SSPV solenoid may be reduced, thus streamlined nuclear reactor operations.

A nuclear reactor scram control system for a nuclear reactor includes a solenoid pilot valve (SSPV). The SSPV includes a solenoid indicator light electrically coupled to an SSPV solenoid of the SSPV. The solenoid indicator light may be selectively activated based on an energization state of the SSPV solenoid, thereby providing an immediate and visually observable indication of the SSPV energization state. The immediate and visually observable indication of the SSPV energization state may enable quicker and more reliable verification of SSPV solenoid energization state. As a result, operator radiation exposure associated with verification may be reduced, and a risk of inadvertent nuclear reactor scram based on a de-energized SSPV solenoid may be reduced, thus streamlined nuclear reactor operations.

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.

To provide a control rod drive system and an inspection method of the control rod drive system capable of performing inspection safely and effectively. A control rod drive system controlling operation by supplying a hydraulic pressure to control rod drive mechanisms includes a plurality of first hydraulic control units supplying the hydraulic pressure to corresponding given control rod drive mechanisms and a second hydraulic control unit supplying the hydraulic pressure to corresponding given control rod drive mechanisms of the first hydraulic control unit as an inspection target instead of the first hydraulic control unit as the inspection target selected from the respective first hydraulic control units.

To provide a control rod drive system and an inspection method of the control rod drive system capable of performing inspection safely and effectively. A control rod drive system controlling operation by supplying a hydraulic pressure to control rod drive mechanisms includes a plurality of first hydraulic control units supplying the hydraulic pressure to corresponding given control rod drive mechanisms and a second hydraulic control unit supplying the hydraulic pressure to corresponding given control rod drive mechanisms of the first hydraulic control unit as an inspection target instead of the first hydraulic control unit as the inspection target selected from the respective first hydraulic control units.

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.

An internal control rod drive mechanism (CRDM) including an electric motor is disposed in a nuclear reactor and further includes a support surface with sealed electrical connectors electrically connected with the electric motor power the motor. The internal CRDM is disposed on a support element secured inside the nuclear reactor. The support element includes sealed electrical connectors mating with the sealed electrical connectors on the support surface of the internal CRDM to power the electric motor. The sealed electrical connectors may be sealed glass, ceramic, or glass-ceramic connectors welded onto the ends of the MI cables extending from the motor. Springs, are disposed between the mating sealed electrical connectors of the support element and the support surface. A purge line is integrated with each mated connection.

An internal control rod drive mechanism (CRDM) including an electric motor is disposed in a nuclear reactor and further includes a support surface with sealed electrical connectors electrically connected with the electric motor power the motor. The internal CRDM is disposed on a support element secured inside the nuclear reactor. The support element includes sealed electrical connectors mating with the sealed electrical connectors on the support surface of the internal CRDM to power the electric motor. The sealed electrical connectors may be sealed glass, ceramic, or glass-ceramic connectors welded onto the ends of the MI cables extending from the motor. Springs, are disposed between the mating sealed electrical connectors of the support element and the support surface. A purge line is integrated with each mated connection.

A standoff supporting a control rod drive mechanism (CRDM) in a nuclear reactor is connected to a distribution plate which provides electrical power and hydraulics. The standoff has connectors that require no action to effectuate the electrical connection to the distribution plate other than placement of the standoff onto the distribution plate. This facilitates replacement of the CRDM. In addition to the connectors, the standoff has alignment features to ensure the CRDM is connected in the correct orientation. After placement, the standoff may be secured to the distribution plate by bolts or other fasteners. The distribution plate may be a single plate that contains the electrical and hydraulic lines and also is strong enough to provide support to the CRDMs or may comprise a stack of two or more plates.

A standoff supporting a control rod drive mechanism (CRDM) in a nuclear reactor is connected to a distribution plate which provides electrical power and hydraulics. The standoff has connectors that require no action to effectuate the electrical connection to the distribution plate other than placement of the standoff onto the distribution plate. This facilitates replacement of the CRDM. In addition to the connectors, the standoff has alignment features to ensure the CRDM is connected in the correct orientation. After placement, the standoff may be secured to the distribution plate by bolts or other fasteners. The distribution plate may be a single plate that contains the electrical and hydraulic lines and also is strong enough to provide support to the CRDMs or may comprise a stack of two or more plates.