Nonaqueous processing methods

A high-temperature process utilizing molten salt extraction from molten metal alloys has been developed for purification of spent power reactor fuels. Experiments with laboratory-scale processing operations show that purification and throughput parameters comparable to the Barnwell Purex process can be achieved by pyrochemical processing in equipment one-tenth the size, with all wastes being discharged as stable metal alloys at greatly reduced volume and disposal cost. This basic technology can be developed for large-scale processing of spent reactor fuels. 13 references, 4 figures

Applications of molten salts in plutonium processing

Plutonium is efficiently recovered from scrap at Los Alamos by a series of chemical reactions and separations conducted at temperatures ranging from 700 to 900/sup 0/C. These processes usually employ a molten salt or salt eutectic as a heat sink and/or reaction medium. Salts for these operations were selected early in the development cycle. The selection criteria are being reevaluated. In this article we describe the processes now in use at Los Alamos and our studies of alternate salts and eutectics

Recovery of plutonium by pyroredox processing

Using pyrochemical oxidation and reduction, we have developed a process to recover the plutonium in impure scrap with less than 95% plutonium. This plutonium metal was further purified by pyrochemical electrorefining. During development of the procedures, depleted electrorefining anodes were processed, and over 80% of the plutonium was recovered as high-purity metal in one electrorefining cycle. Over 40 kg of plutonium has been recovered from 55 kg of impure anodes with our procedures. 6 refs., 2 figs., 5 tabs

Preparation of fused chloride salts for use in pyrochemical plutonium recovery operations at Los Alamos

The Plutonium Metal Technology Group at Los Alamos routinely uses pyrochemical processes to produce and purify plutonium from impure sources. The basic processes (metal production, metal purification, and residue treatment) involve controlling oxidation and reduction reactions between plutonium and its compounds in molten salts. Current production methods are described, as well as traditional approaches and recent developments in the preparation of solvent salts for electrorefining, molten salt extraction, lean metal (pyroredox) purification, and direct oxide reduction

Wastes from plutonium conversion and scrap recovery operations

This report deals with the handling of defense-related wastes associated with plutonium processing. It first defines the different waste categories along with the techniques used to assess waste content. It then discusses the various treatment approaches used in recovering plutonium from scrap. Next, it addresses the various waste management approaches necessary to handle all wastes. Finally, there is a discussion of some future areas for processing with emphasis on waste reduction. 91 refs., 25 figs., 4 tabs

Coordinated safeguards for materials management in a nitrate-to-oxide conversion facility

The conceptual design of a materials management system for safeguarding special nuclear materials in a plutonium nitrate-to-oxide conversion facility is developed and evaluated. Dynamic material balances are drawn from information provided by nondestructive-analysis techniques, process-control instrumentation, and conventional chemical analyses augmented by process-monitoring devices. Powerful statistical methods, cast in the framework of decision analysis and applied to unit-process accounting areas, ensure adequate spatial and temporal quantification of possible diversion with minimal process disruption. Modeling and simulation techniques assist in evaluating the sensitivity of the system to various diversion schemes and in comparing safeguards strategies. Features that would improve the safeguardability of the conversion process are discussed