TerraPower, LLC

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.

An anti-proliferation technique is disclosed to reduce the likelihood of nuclear proliferation due to the use fissionable fuel salts. The technique includes doping the fuel salt with one or more elements (referred to herein as activation dopants) that, upon exposure to neutrons such as would occur in the fuel salt when a reactor is in operation, undergo a nuclear reaction to, directly or indirectly, form highly active “protecting isotopes” (of the same element as the activation dopant or a different element). A sufficient mass of activation dopants is used so that the Figure of Merit (FOM) of the fuel salt is decreased to below 1.0 within some target number of days of fission. This allows the FOM of the fuel salt to be controlled so that the fuel becomes too dangerous to handle before to the creation of a significant amount of weaponizable isotopes.

Embodiments of methods for improving mesophase pitch for carbon fiber production using supercritical carbon dioxide are described. The methods improve the relative amount and quality of mesophase pitch in feedstocks, such as coal tar, already having at least some mesophase pitch. One particular method includes performing a sCO2/toluene extraction on the coal tar to obtain a toluene insoluble fraction of the coal tar; mixing the toluene insoluble fraction with sCO2 to obtain a sCO2/toluene insoluble fraction mixture; and extruding the sCO2/toluene insoluble fraction mixture, thereby separating the sCO2 from the toluene insoluble fraction to obtain fibers of mesophase pitch.

Targetry coupled separation refers to enhancing the production of a predetermined radiation product through the selection of a target (including selection of the target material and the material's physical structure) and separation chemistry in order to optimize the recovery of the predetermined radiation product. This disclosure describes systems and methods for creating (through irradiation) and removing one or more desired radioisotopes from a target and further describes systems and methods that allow the same target to undergo multiple irradiations and separation operations without damage to the target. In contrast with the prior art that requires complete dissolution or destruction of a target before recovery of any irradiation products, the repeated reuse of the same physical target allowed by targetry coupled separation represents a significant increase in efficiency and decrease in cost over the prior art.

This document describes a method for reducing the corrosivity of certain magnesium salts. The salt product resulting from the method exhibits reduced corrosion of steels that come into contact with the salt relative to salt compositions that are not so treated. This makes such treated salts more efficient coolant salts as they will require less equipment replacement over time. The method uses magnesium metal to reduce unwanted impurities in the salts the reduced impurities are then removed as either gas or precipitate from the now purified salt. Without being bound to one particular theory, it is believed that the reduction of the level of impurities in the salt results in a salt with substantially reduced corrosiveness to steel.

An in-vessel fuel transfer machine may be permanently affixed to a nuclear reactor and remain in place during power operations. The in-vessel fuel transfer machine may include a pantograph machine that positions a grapple in order to access any fuel socket location within the core and move any of the core assemblies between the core, an in-vessel fuel storage area, and a fuel elevator. The grapple may be positioned through a combination of movements, such as, rotating a rotating plug assembly, rotating the in-vessel fuel transfer machine, extending the pantograph arms, and shuttling the grapple along a leg. The grapple may be compliant to accommodate deformed core assemblies and may be configured to pivot to more closely align to an eccentric core assembly handling socket or be moveable in a horizontal plane to accommodate a deformed core assembly during insertion or withdrawal.

A nuclear reactor is constructed in sub-modules and super modules which are manufactured, packaged, and shipped to a construction site. At least some of the modules are packaged in suitable shielding containers or portions of containers, which may be steel. The modules are assembled on-site, and some of the modules remain within their respective shipping containers after assembly. One or more of the shipping containers may be used as concrete forms to support the pouring of concrete in between selected modules. The concrete may be used for structural support, shielding, or both.

A vaporizer includes an outer tube configured to receive a flow of heated gas and an inner tube disposed at least partially within the outer tube. The inner tube is spaced apart from the outer tube such that the flow of heated gas is channeled through an annular space therebetween. The vaporizer also includes a crucible disposed at least partially within the inner tube. The crucible is extendable and retractable relative to the inner tube and within the outer tube. The crucible is configured to hold a molten metal such that a surface area of the molten metal exposed to the flow of heated gas is adjustable based on the position of the crucible relative to the inner tube. A heater is configured to vaporize the molten material and the vapor mixes with the flow of heated gas.

A failed fuel pin emits cesium into the primary sodium coolant and xenon into the cover gas in a reactor vessel. A pipe containing radioactive liquid sodium accepts flowing primary sodium from the reactor vessel. A radiation detector is positioned adjacent the pipe such that gamma radiation emitted from the pipe can be measured. The pipe may be isolated to increase detection limits by allowing short-lived isotopes to decay. The isotopic ratio of 137 Cs/ 134 Cs can be measured, which can be used to determine the burnup of a fuel assembly from within the core, and therefore, the failed fuel assembly can be identified based at least in part on the burnup. Further, mass spectrometry may be used to measure the ratio of a stable and unstable xenon isotope. The identification techniques may be used in conjunction to quickly identify a failed fuel assembly in-situ and during reactor operation.

In a sodium fast reactor, a bypass pipe is fluidly coupled to the primary sodium pump discharge and diverts a portion of the primary sodium coolant to an instrument assembly. The bypass pipe routes flowing sodium upward toward the reactor head where it fluidly couples to the instrument assembly. The instrument assembly includes an instrument tank and selectively swappable instrument modules. The instrument modules can be configured to measure flow, pressure, temperature, and fluid level, among other things. The instrument assembly is located relatively close to the reactor head and close to the sodium level in the sodium pool and is accessible from above the reactor head for quick and efficient removal and replacement of the entire instrument assembly or individual instruments.