Abstract: 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.

Abstract: 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 137Cs/134Cs 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Sodium-cesium detection systems and methods for the simultaneous detection of both sodium (Na) and cesium (Cs) in gas are provided. The detection systems include two non-identical ionization chambers each having an anode and a cathode that ionize Na and Cs in gas. Each ionization chamber generates a current proportional to the Na and Cs concentration and based on the current, Na concentration and Cs concentration in the gas is determined.

Abstract: Sodium-cesium detection systems and methods for the simultaneous detection of both sodium (Na) and cesium (Cs) in gas are provided. The detection systems include two non-identical ionization chambers each having an anode and a cathode that ionize Na and Cs in gas. Each ionization chamber generates a current proportional to the Na and Cs concentration and based on the current, Na concentration and Cs concentration in the gas is determined.