Abstract: The thermochemical conversion of biomass material to one or more reaction products includes generating thermal energy with at least one heat source, providing a volume of feedstock, providing a volume of supercritical fluid, transferring a portion of the generated thermal energy to the volume of supercritical fluid, transferring at least a portion of the generated thermal energy from the volume of supercritical fluid to the volume of feedstock, and performing a thermal decomposition process on the volume of feedstock with the thermal energy transferred from the volume of supercritical fluid to the volume of the feedstock in order to form at least one reaction product.

Abstract: 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.

Abstract: Configurations of molten fuel salt reactors are described that allow for active cooling of the containment vessel of the reactor by the primary coolant. Furthermore, naturally circulating reactor configurations are described in which the reactor cores are substantially frustum-shaped so that the thermal center of the reactor core is below the outlet of the primary heat exchangers. Heat exchanger configurations are described in which welded components are distanced from the reactor core to reduce the damage caused by neutron flux from the reactor. Radial loop reactor configurations are also described.

Abstract: This disclosure describes systems and methods for using pyrolysis tail gas as the source for additional hydrogen to be used in the pyrolysis reaction. Tail gas is separated from the pyrolysis products and a portion of the tail gas is converted into formic acid (HCOOH). The formic acid is then injected into the pyrolysis reactor where it becomes the donor of two monohydrogen atoms and is ultimately converted into CO2 under reaction conditions. In this fashion, a closed loop pyrolysis hydrogen donor system may be created utilizing a generally non-toxic intermediary derived from the pyrolysis reaction products. This disclosure also describes using a ruthenium catalyst supported on particles of activated carbon to improve the yield of pyrolysis reactions.

Abstract: A rod transfer assembly has an outer rotating plug. A pick-up arm assembly extends from the outer rotating plug and includes a pivoting arm. An inner rotating plug is disposed off-center from and within the outer rotating plug and is rotatable independent of a rotation of the outer rotating plug. An access port rotating plug is disposed off-center from and within the inner rotating plug and is rotatable independent of rotation of the outer and inner rotating plugs. A pull arm extends from the access port rotating plug.

Abstract: Sodium-cesium trap systems and methods for the simultaneous removal of both sodium (Na) and cesium (Cs) in gas are provided. The trap system includes a contacting vessel having an inlet and an outlet with carrier gas channeled therethrough. A heating system maintains a temperature gradient across the contacting vessel between a first temperature at the inlet and a second temperature at the outlet such that sodium and cesium contained within the carrier gas are condensed into liquid and the carrier gas exiting the vessel is substantially free of sodium and cesium.

Abstract: Configurations of molten fuel salt reactors are described that include an auxiliary cooling system which shared part of the primary coolant loop but allows for passive cooling of decay heat from the reactor. Furthermore, different pump configurations for circulating molten fuel through the reactor core and one or more in vessel heat exchangers are described.

Abstract: This disclosure describes methods for improving the performance and consistency of steels by closely controlling the initial homogenization of steel compositions prior to hot working. Experimental data is provided illustrating that the traditional austenitization techniques do not take into account diffusion of the various components within a steel composition and, as such, may not completely homogenize the steel composition. In the methods described in this disclosure, the initial step of austenitizing the steel ingot is altered to achieve a more homogenous distribution of the different components throughout the ingot. The improved method includes heating the steel composition to a temperature within the upper half of the pure austenitic phase temperature range and maintaining the steel composition at that temperature for a period of time determined based on the diffusivity in the austenitic phase of the steel composition of at least one constituent of the steel.

Abstract: This disclosure describes systems and methods for synthesizing UCl3 from UCl4. These systems and methods may also be used to directly synthesize binary and ternary embodiments of uranium salts of chloride usable as nuclear fuel in certain molten salt reactor designs. The systems and methods described herein are capable of synthesizing any desired uranium chloride fuel salt that is a combination of UCl4, UCl3 and one or more non-fissile chloride compounds, such as NaCl. In particular, the systems and methods described herein are capable of synthesizing any UCl3—UCl4—NaCl or UCl3—NaCl fuel salt composition from UCl4—NaCl.

Abstract: A dynamic neutron reflector assembly for a “breed-and-burn” fast reactor incrementally adjusts neutron spectrum and reactivity in a reactor core. The composition of materials in the dynamic neutron reflector may be adjusted to change neutron reflectivity levels, or to introduce neutron moderating or absorption characteristics. The dynamic neutron reflector may contain a flowing reflecting liquid of adjustable volume and/or density. Submergible members may be selectively inserted into the flowing reflecting liquid to alter its volume and introduce other neutron modifying effects such as moderation or absorption. Selective insertion of the submergible members allows for concentration of the neutron modifying effects in a selected portion of the reactor core. The flowing reflecting liquid may also act as a secondary coolant circuit by exchanging heat with the molten fuel salt.

Abstract: Exemplary embodiments provide automated nuclear fission reactors and methods for their operation. Exemplary embodiments and aspects include, without limitation, controlling a propagating nuclear deflagration wave within a burning wavefront heat generating region, moveable neutron modifying structures, variable burn-up, programmable nuclear thermostats, fast flux irradiation, temperature-driven surface area/volume ratio neutron absorption, low coolant temperature cores, refueling, and the like.

Abstract: 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.

Abstract: A getter element includes a getter material reactive with a fission product contained within a stream of liquid and/or gas exiting a fuel assembly of a nuclear reactor. At least one transmission pathway passes through the getter element that is sufficiently sized to maintain a flow of the input stream through the getter element at above a selected flow level. At least one transmission pathway includes a reaction surface area sufficient to uptake a pre-identified quantity of the fission product.

Abstract: This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor in which one or more primary heat exchangers are located above the reactor core of the nuclear reactor.

Abstract: Configurations of molten fuel salt reactors are described that utilize neutron-reflecting coolants or a combination of primary salt coolants and secondary neutron-reflecting coolants. Further configurations are described that circulate liquid neutron-reflecting material around an reactor core to control the neutronics of the reactor. Furthermore, configurations which use the circulating neutron-reflecting material to actively cool the containment vessel are also described.

Abstract: This document describes methods for pretreating coal to create either a dried coal or a char product that is stable in the outdoor environment and is more efficient as a feedstock for gasification or other processes than the original coal. Embodiments of the methods include pulverizing and pelletizing the coal, and pretreating the coal pellets to obtain a stable pellet of either dried coal or a stable pellet of chared coal (coal char). The pellets created by the described methods have undergone deoxygenation and carbonization improving their handling and storage properties and, in some cases, energy density. Pore structures within the pellets are stabilized physically and chemically so that the uptake of moisture into dry coal, that leads to internal heat generation, is greatly reduced. Chars are also, therefore, stable against transitions from a dry state to a wet state and less prone to self-ignition.

Abstract: 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.

Abstract: Sodium-cesium trap systems and methods for the simultaneous removal of both sodium (Na) and cesium (Cs) in gas are provided. The trap system includes a contacting vessel having an inlet and an outlet with carrier gas channeled therethrough. A heating system maintains a temperature gradient across the contacting vessel between a first temperature at the inlet and a second temperature at the outlet such that sodium and cesium contained within the carrier gas are condensed into liquid and the carrier gas exiting the vessel is substantially free of sodium and cesium.

Abstract: A molten salt reactor includes a nuclear reactor core for sustaining a nuclear fission reaction fueled by a molten fuel salt. A molten fuel salt control system removes a volume of the molten fuel salt from the nuclear reactor core to maintain a reactivity parameter within a range of nominal reactivity. The molten fuel salt control system includes a molten fuel salt exchange system that fluidically couples to the nuclear reactor core and exchanges a volume of the molten fuel salt with a volume of a feed material containing a mixture of a selected fertile material and a carrier salt. The molten fuel salt control system can include a volumetric displacement control system having one or more volumetric displacement bodies insertable into the nuclear reactor core. Each volumetric displacement body can remove a volume of molten fuel salt from the nuclear reactor core, such as via a spill-over system.

Abstract: 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.