Abstract: Packaging structures and systems are used for handling components for use in a nuclear reactor. The packaging protects the component during transport and handling and then dissolves in liquid in the nuclear reactor or fuel pool. The packaging need not be removed and may block flow paths or otherwise interfere with operability were it not for its dissolution. The packaging may include shock absorbers in a fuel assembly or a seal on a water rod in the assembly. Mechanical, frictional, or chemical retaining materials may be used to secure the packaging and may also dissolve in the liquid. For a light water reactor, polymers, protein gels, and plastics can all be used where they will dissolve in the water and are otherwise compatible with reactor chemistry and neutronics. Materials with higher temperatures for solubility may be used because they will dissolve when reactor operations commence.

Abstract: Packaging structures and systems are used for handling components for use in a nuclear reactor. The packaging protects the component during transport and handling and then dissolves in liquid in the nuclear reactor or fuel pool. The packaging need not be removed, as so can block flow paths or otherwise interfere with operability were it not for its dissolution. The packaging may include shock absorbers in a fuel assembly or a seal on a water rod in the assembly. Mechanical, frictional, or chemical retaining materials may be used to secure the packaging and may also dissolve in the liquid. For a light water reactor, polymers, protein gels, and plastics can all be used where they will dissolve in the water and are otherwise compatible with reactor chemistry and neutronics. Materials with higher temperatures for solubility may be used because they will dissolve when reactor operations commence.

Abstract: Methods and materials for preparing investment molds useful in pressure infiltration casting of near net-shape metal or metal matrix composite (MMC) components. One embodiment of the invention includes disposing a slurry of an appropriately sized refractory material and a vehicle around a preform or fugitive pattern, removing the bulk of the vehicle, then curing/drying the refractory material to create an investment mold of the invention. Subsequently, pressure infiltration casting with a molten infiltrant using the investment mold permits infiltration of the mold cavity and/or preform without infiltration of the investment mold. As a result, the investment mold readily is removed to provide the near net-shape metal or MMC component. In other embodiments of the invention, a non-fugitive pattern is used, typically with a modified refractory cement of the invention.