A nuclear reactor seismic isolation assembly includes an enclosure that defines a volume; a plastically-deformable member mounted, at least in part, within the volume; and a stretching member moveable within the enclosure to plastically-deform the plastically-deformable member in response to a dynamic force exerted on the enclosure.

A nuclear reactor seismic isolation assembly includes an enclosure that defines a volume; a plastically-deformable member mounted, at least in part, within the volume; and a stretching member moveable within the enclosure to plastically-deform the plastically-deformable member in response to a dynamic force exerted on the enclosure.

A securing device is installable on an outer circumferential surface of a nuclear reactor core shroud and in contact with an inner circumferential surface of a pressure vessel. The securing device includes a base configured for contacting the outer circumferential surface of the nuclear reactor core shroud. The securing device also includes a radial extender including an actuator, a stationary support section fixed to the base and a movable contact section. The radial extender is configured such that the movable contact section is movable along the stationary support section by the actuator to force the movable contact section radially into the inner circumferential surface of the pressure vessel.

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.

The invention relates to the field of thermonuclear fusion and can be used in devices for electrically connecting internal elements of the reactor chamber to the vacuum vessel of the nuclear fusion reactor. The present device for electrically connecting elements inside the chamber of a reactor to the vacuum vessel of the nuclear fusion reactor comprises lamellar electrically conductive elements with surface portions oriented in different directions, said elements being stacked between flanges. The device is made as an integral unit, where profiled slots are formed with connecting walls therebetween. The connecting walls constitute the electrically conductive elements and have profiled sections of an increased thickness between the differently oriented surface portions at transition areas to the flanges provided at the end parts of the integral unit. The technical effect of the present invention is an increase in the cyclic strength of the electrically conductive elements at the transition areas between the elements and the flanges and between the differently oriented surface portions (at bends) of the elements. The invention also provides that the electrically conductive elements have similar technical characteristics.

The invention relates to the field of thermonuclear fusion and can be used in devices for electrically connecting internal elements of the reactor chamber to the vacuum vessel of the nuclear fusion reactor. The present device for electrically connecting elements inside the chamber of a reactor to the vacuum vessel of the nuclear fusion reactor comprises lamellar electrically conductive elements with surface portions oriented in different directions, said elements being stacked between flanges. The device is made as an integral unit, where profiled slots are formed with connecting walls therebetween. The connecting walls constitute the electrically conductive elements and have profiled sections of an increased thickness between the differently oriented surface portions at transition areas to the flanges provided at the end parts of the integral unit. The technical effect of the present invention is an increase in the cyclic strength of the electrically conductive elements at the transition areas between the elements and the flanges and between the differently oriented surface portions (at bends) of the elements. The invention also provides that the electrically conductive elements have similar technical characteristics.

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.

Clamps can be secured to a slip joint and limit flow through the same by seating on a diffuser axially regardless of wear and damage in the slip joint. An extension from the clamp seats to the inlet mixer. These extensions can be adjusted from outside the clamp to achieve an individual preload or flow limitation through the slip joint. The extension may be an O-ring or other shape. A biasing drive may connect to and move the extension from an outside surface of the clamp. The biasing drive may include a threaded cap in an outer groove that is linked to a plunger via a spring. Clamps are fabricated of materials that maintain their physical properties when exposed to an operating nuclear reactor environment and may be relatively rigid and resilient metals.

Clamps can be secured to a slip joint and limit flow through the same by seating on a diffuser axially regardless of wear and damage in the slip joint. An extension from the clamp seats to the inlet mixer. These extensions can be adjusted from outside the clamp to achieve an individual preload or flow limitation through the slip joint. The extension may be an O-ring or other shape. A biasing drive may connect to and move the extension from an outside surface of the clamp. The biasing drive may include a threaded cap in an outer groove that is linked to a plunger via a spring. Clamps are fabricated of materials that maintain their physical properties when exposed to an operating nuclear reactor environment and may be relatively rigid and resilient metals.

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.