Gamma Assay of Uranium and Plutonium 5 v. Analytical Methods and Automated Instruments for the Determination of Plutonium and Uranium

Progress continued on method development for the dissolution of difficult-to-dissolve materials, the automated analysis of plutonium and uranium, the preparation of plutonium materials for the Safeguard Analytical Laboratory Evaluation (SALE) Program, and the analysis of HTGR fuel and SALE uranium materials. The previously developed Teflon-container, metal-shell apparatus was applied to the dissolution of various nuclear materials. Gas-solid reactions, mainly using chlorine at elevated temperatures, are promising for separating uranium from refractory compounds. An automated spectrophotometer designed for determining plutonium and uranium has been tested successfully by the New Brunswick Laboratory. Procedures were developed for this instrument to analyze uranium-plutonium mixtures and the effects of diverse ions upon the analysis of plutonium and uranium were further established. A versatile apparatus was assembled to develop electrotitrimetric methods that will serve as *he basis for precise automated determinations of plutonium. Progress with the first of these methods is reported. Plutonium materials prepared for the SALE Program were plutonium oxide, uranium-plutonium mixed oxide, and plutonium metal. Improvements were made in the methods used for determining uranium in HTGR fuel materials and SALE uranium materials. Plutonium metal samples were 'prepared, characterized, and distributed, and half-life measurements were in progress as part of an inter-ERDAlaboratory program to measure accuracy the half-lives of longlived plutonium isotopes.