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.

Provided is an apparatus for evaluating a response time of a plant protection system. The apparatus includes: a classification module classifying a design process related to a response time requirement of each channel performing a safety function into four operations of a safety analysis operation, a system design operation, a response time analysis operation, and a response time test operation; and an integrated evaluation module determining whether a response time evaluation is proper based on a time t1 derived in the safety analysis operation, a time t2 derived in the system design operation, a time t3 derived in the response time analysis operation, and a time t4 derived in the response time test operation.

Provided is an apparatus for evaluating a response time of a plant protection system. The apparatus includes: a classification module classifying a design process related to a response time requirement of each channel performing a safety function into four operations of a safety analysis operation, a system design operation, a response time analysis operation, and a response time test operation; and an integrated evaluation module determining whether a response time evaluation is proper based on a time t1 derived in the safety analysis operation, a time t2 derived in the system design operation, a time t3 derived in the response time analysis operation, and a time t4 derived in the response time test operation.

A damping area or “dash pot” on the upper ends of control rods absorb energy from dropped control rod assemblies without narrowing the diameter of guide tubes. As a result, coolant can freely flow through the guide tubes reducing boiling water issues. The dampening area reduces a separation distance between an outside surface of the control rod and an inside surface of the guide tubes decelerating the control rods when entering a top end of the guide tubes. In another example, the dampening area may be located on a drive shaft. The dampening area may have a larger diameter than an opening in a drive shaft support member that decelerates the drive shaft when dropped by a drive mechanism.

A boiling water reactor system includes a reactor vessel including a reactor core. A steam line is in communication with the reactor core and a turbine that is connected to an electrical generator. A dry standby liquid control system includes a standby vessel containing dry powder containing boron and including a high pressure water supply in communication with the standby vessel via a first closed valve, wherein the standby vessel is in communication with the reactor vessel via a second closed valve.

A boiling water reactor system includes a reactor vessel including a reactor core. A steam line is in communication with the reactor core and a turbine that is connected to an electrical generator. A dry standby liquid control system includes a standby vessel containing dry powder containing boron and including a high pressure water supply in communication with the standby vessel via a first closed valve, wherein the standby vessel is in communication with the reactor vessel via a second closed valve.

A rotation apparatus is usable with a control drum in a nuclear environment. The control drum is situated on a shaft that is rotatable about a horizontal axis of rotation, and the control drum includes an absorber portion and a reflector portion. The rotation apparatus includes a rotation mechanism that is structured to apply to the shaft in an operational position a force that biases the shaft to rotate toward a shutdown position, with the force being resisted by a motor to retain the shaft in the operational position when the motor is powered. The force is not resisted when the motor is unpowered. The rotation apparatus further includes a rotation management system that controls the rotation of the shaft.

A rotation apparatus is usable with a control drum in a nuclear environment. The control drum is situated on a shaft that is rotatable about a horizontal axis of rotation, and the control drum includes an absorber portion and a reflector portion. The rotation apparatus includes a rotation mechanism that is structured to apply to the shaft in an operational position a force that biases the shaft to rotate toward a shutdown position, with the force being resisted by a motor to retain the shaft in the operational position when the motor is powered. The force is not resisted when the motor is unpowered. The rotation apparatus further includes a rotation management system that controls the rotation of the shaft.

A nuclear plant includes a nuclear reactor, a containment structure that at least partially defines a containment environment of the nuclear reactor, and a passive containment cooling system that causes coolant fluid to flow downwards from a coolant reservoir to a bottom of a coolant channel coupled to the containment structure and rise through the coolant channel toward the coolant reservoir due to absorbing heat from the nuclear reactor. A check valve assembly, in fluid communication with the coolant reservoir, selectively enables one-way flow of a containment fluid from the containment environment to the coolant reservoir, based on a pressure at an inlet being equal to or greater than a threshold magnitude. A fusible plug, in fluid communication with the coolant reservoir at a bottom vertical depth below the bottom of the coolant reservoir, enables coolant fluid to flow into the containment structure based on at least partially melting.