Thin metal encapsulation of fission foils and oxide discs by resistance welding

Abstract

The Interlaboratory LMFBR Reaction Rate (ILRR) Program was established in 1971 by the U.S. Atomic Energy Commission, Division of Reactor Research and Development. The objective of this program was the development of the capability to precisely measure neutron-induced reaction rates of LMFBR fuels and related materials. The Isotope Research Materials Laboratory of the Oak Ridge National Laboratory has been actively involved in development and fabrication of various types of dosimeters to meet the demands of this program since its inception. One type of dosimeter utilized in this program has been thin metallic and oxide discs of uranium, plutonium, and neptunium isotopes. Because of the extreme reactivity and radiotoxicity of these materials, it has been necessary to fabricate these dosimeters with a welded closure. The stringent dimensional specifications and the extreme thinness of the container materials precluded the use of conventional welding techniques. This report describes the equipment and procedures employed to attain the welded closures required to hermetically seal these thin metal containers.