Abstract: A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

Abstract: A hydrogen permeation resistant barrier is formed by diffusing aluminum into an iron or nickel alloy and forming an intermetallic aluminide layer.

Abstract: The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.

Abstract: The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, filling the tubing with fine alumina particles, flattening and coiling and pressing an upper portion of the tubing at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed lower portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, uniformly filling a normally upper portion of the tubing with a predetermined thickness layer of fine alumina particles, flattening and doubly folding and pressing the upper portion of the tubing at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed normally lower portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, filling the tubing with fine alumina particles, flattening and coiling and pressing an upper portion of the tubing at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed lower portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, placing a predetermined number of strands of stabilized zirconium oxide yarn of predetermined diameter longitudinally into one end of the tubing a predetermined distance therein, flattening and coiling and pressing the end portion of the tubing containing the yarn at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed (normally lower) portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.This is a division of application Ser. No. 376,527, filed July 5, 1973, now U.S. Pat. No. 3,803,816.

Abstract: A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, filling the tubing with fine alumina particles, flattening and coiling and pressing an upper portion of the tubing at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed lower portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin.