Systems, devices, and methods include a valve actuator to open and close a valve in fluid communication with a fluid control system. The valve actuator includes a motor having windings of wire. The wire includes insulating material disposed over a conductor.

A method of operating a nuclear reactor includes operating a valve actuator to open and close a valve in fluid communication with a nuclear reactor fluid control system. The valve actuator includes a motor having windings of magnet wire. The magnet wire includes a layer of insulating material disposed over a conductor. The layer of insulating material comprises polyetheretherketone (PEEK) and has a thickness between about 0.025 mm and about 0.381 mm. A method of replacing a valve actuator motor with such a motor having windings formed of PEEK-insulated magnet wire is also disclosed. A method of coupling a valve actuator with such a motor having windings formed of PEEK-insulated magnet wire to a valve is also disclosed.

A method of operating a nuclear reactor includes operating a valve actuator to open and close a valve in fluid communication with a nuclear reactor fluid control system. The valve actuator includes a motor having windings of magnet wire. The magnet wire includes a layer of insulating material disposed over a conductor. The layer of insulating material comprises polyetheretherketone (PEEK) and has a thickness between about 0.025 mm and about 0.381 mm. A method of replacing a valve actuator motor with such a motor having windings formed of PEEK-insulated magnet wire is also disclosed. A method of coupling a valve actuator with such a motor having windings formed of PEEK-insulated magnet wire to a valve is also disclosed.

A method for in-situ subsurface isolation of nuclear material at a nuclear power or nuclear waste facility during an emergency includes a borehole located in close proximity and at a depth sufficient to safely isolate the radioactive material. A gravity fracture in the surrounding rock formation is located at the bottom end of the borehole, with the radioactive material entering the gravity fracture. A dense slurry or fluid could be mixed with the radioactive material to create and propagate the gravity fracture.

A gas supply apparatus of the present invention includes a gas discharge line of a first electromagnetic valve having s a switching valve placed therein, and a second electromagnetic valve placed between the switching valve and a gas supply source. The switching valve switches between a gas discharge from the first electromagnetic valve and a gas supply to the first electromagnetic valve. At the time of a normal operation, the second electromagnetic valve opens a gas discharge line side and closes a switching valve side, and when the power source is lost, the second electromagnetic valve opens the switching valve side and closes the gas discharge line side. In this way, even when the power source is lost, an operating valve can not only be operated remotely but also be operated safely by a remote operator.

A gas supply apparatus of the present invention includes a gas discharge line of a first electromagnetic valve having s a switching valve placed therein, and a second electromagnetic valve placed between the switching valve and a gas supply source. The switching valve switches between a gas discharge from the first electromagnetic valve and a gas supply to the first electromagnetic valve. At the time of a normal operation, the second electromagnetic valve opens a gas discharge line side and closes a switching valve side, and when the power source is lost, the second electromagnetic valve opens the switching valve side and closes the gas discharge line side. In this way, even when the power source is lost, an operating valve can not only be operated remotely but also be operated safely by a remote operator.

A nuclear reactor includes a reactor core disposed in a reactor pressure vessel. A radiological containment contains the nuclear reactor and includes a concrete floor located underneath the nuclear reactor. An ex vessel corium retention system includes flow channels embedded in the concrete floor located underneath the nuclear reactor, an inlet in fluid communication with first ends of the flow channels, and an outlet in fluid communication with second ends of the flow channels. In some embodiments the inlet is in fluid communication with the interior of the radiological containment at a first elevation and the outlet is in fluid communication with the interior of the radiological containment at a second elevation higher than the first elevation. The radiological containment may include a reactor cavity containing a lower portion of the pressure vessel, wherein the concrete floor located underneath the nuclear reactor is the reactor cavity floor.

A nuclear reactor includes a reactor core disposed in a reactor pressure vessel. A radiological containment contains the nuclear reactor and includes a concrete floor located underneath the nuclear reactor. An ex vessel corium retention system includes flow channels embedded in the concrete floor located underneath the nuclear reactor, an inlet in fluid communication with first ends of the flow channels, and an outlet in fluid communication with second ends of the flow channels. In some embodiments the inlet is in fluid communication with the interior of the radiological containment at a first elevation and the outlet is in fluid communication with the interior of the radiological containment at a second elevation higher than the first elevation. The radiological containment may include a reactor cavity containing a lower portion of the pressure vessel, wherein the concrete floor located underneath the nuclear reactor is the reactor cavity floor.

A curvilinear electromagnetic pump is configured to follow a curve, such as by coupling multiple linear pump segments together that are offset by an angle with respect to each other. The curvilinear electromagnetic pump can curve within two dimensions, or within three dimensions. The curvilinear electromagnetic pump allows for more efficient arrangement of components and systems within a nuclear reactor vessel and allows a significantly reduced reactor vessel height as compared to a linear pump arranged vertically. The curvilinear electromagnetic pump may follow the curvature of the reactor vessel wall and may be entirely disposed near the bottom of the reactor vessel.

A system for attenuating seismic forces includes a reactor pressure vessel containing nuclear fuel and a containment vessel that houses the reactor pressure vessel. Both the reactor pressure vessel and the containment vessel include a bottom head. Additionally, the system includes a base support to contact a support surface on which the containment vessel is positioned in a substantially vertical orientation. An attenuation device is located between the bottom head of the reactor pressure vessel and the bottom head of the containment vessel. Seismic forces that travel from the base support to the reactor pressure vessel via the containment vessel are attenuated by the attenuation device in a direction that is substantially lateral to the vertical orientation of the containment vessel.