Comparison of phosgene, chlorine, and hydrogen chloride as reagents for converting molten CaO. CaCl/sub 2/ to CaCl/sub 2/

One method at Los Alamos for preparing impure plutonium metal from the impure oxide is by batch reduction with calcium metal at 850/sup 0/C in a CaCl/sub 2/ solvent. The solvent salt from this reduction is currently discarded as low-level radioactivity waste only because it is saturated with the CaO byproduct. We have demonstrated a pyrochemical technique for converting the CaO to CaCl/sub 2/ thereby incorporating solvent recycling into the batch reduction process. We will discuss the effectiveness of HCl, Cl/sub 2/, and COCl/sub 2/ as chlorinating agents and recycling actual spent process solvent salts. 6 refs., 8 figs

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

Plutonium metal preparation and purification at Los Alamos, 1984

Plutonium metal preparation and purification are well established at Los Alamos. Metal is prepared by calcothermic reduction of both PuF/sub 4/ and PuO/sub 2/. Metal is purified by halide slagging, casting, and electrorefining. The product from the production sequence is ultrapure plutonium metal. All of the processes involve high temperature operation and all but casting involve molten salt media. Development efforts are fourfold: (1) recover plutonium values from residues; (2) reduce residue generation through process improvements and changes; (3) recycle of reagents, and (4) optimize and integrate all processes into a close-loop system. Plutonium residues are comprised of oxides, chlorides, colloidal metal suspensions, and impure metal heels. Pyrochemical recovery techniques are under development to address each residue. In addition, we are looking back at each residue generation step and are making process changes to reduce plutonium content in each residue. Reagent salt is the principle media used in pyrochemical processing. The regeneration and recycle of these reagents will both reduce our waste handling and operating expense. The fourth area, process optimization, involves both existing processes and new process developments. A status of efforts in all four of these areas will be summarized

Evaluation of the neutron self-interrogation approach for assay of plutonium in high-. cap alpha. ,n materials

Neutron self-interrogation is a proposed method for assay of plutonium in bulk materials with very high ..cap alpha..,n activity. The simple assay approach assumes that neutron multiplication for the calibration standards is the same as that for the bulk items. Efforts to use bulk properties to determine corrections to the calibration for changing multiplication have been initiated. Self-interrogation assays of bulk pyrochemical residues have been performed. Comparison with tag values obtained by difference gives poor agreement. Comparison with tag values obtained by dissolution and destructive analysis gives agreement at the 10% (1sigma) level with no corrections for changing package dimensions or matrix amounts. The agreement improves by a factor of 2 or more if a bulk correction factor (derived from a packaging/matrix study with standards) is applied