Patent Number: 040242099
Section: summary

This invention relates to the manufacture of nuclear fuel rods and, more particularly, to an improved method for making nuclear fuel rods wherein nuclear fuel particles are embedded within solid binder material. Nuclear reactors are sometimes constructed in a configuration wherein the fissionable material or nuclear fuel is formed into or contained in rods held within the reactor core in a desired relationship. One particular rod design which has been found useful is that wherein the nuclear fuel is in particulate form and is held suspended within a solidified binder material molded into the rod form. A convenient way of manufacturing nuclear fuel rods of the foregoing type is to provide a mold into which fuel particles are loaded and into which a plasticized binder fluid material is injected and then solidified in situ. Unfortunately, there have been problems associated with this particular procedure. One problem is that efficiency, materials-use considerations an proper reactor design make it desirable that the fuel particles be densely distributed throughout such fuel rods. To this end, mold cavities are typically filled to the top with nuclear particles prior to injection of the binder. Vibration and shock, however, can cause overspill of the particles from the molds, creating unevenness in fuel loading and a situation in which expensive techniques must be employed to retrieve overspilled nuclear fuel particles. Another problem associated with fuel rods of the type under consideration is that partial settling of the fuel bed may occur as a result of the pressure during injection. This can leave a region within a fuel rod deficient of fuel particles. A final problem is a result of underfilled molds which can result in voids or in creating undesirable end caps of substantially only binder. It is an object of the present invention to provide an improved method for making nuclear fuel rods comprising nuclear fuel particles held together by a binder material. It is another object of the invention to provide a method for manufacturing a nuclear fuel rod in which problems of overspill, particle breakage, and voids are avoided.