Hanford low-activity waste vitrification: A review.

This paper summarizes the vast body of literature (over 200 documents) related to vitrification of the low-activity waste (LAW) fraction of the Hanford tank wastes. Details are provided on the origins of the Hanford tank wastes that resulted from nuclear operations conducted between 1944 and 1989 to support nuclear weapons production. Waste treatment processes are described, including the baseline process to separate the tank waste into LAW and high-level waste fractions, and the LAW vitrification facility being started at Hanford.

Dechlorination Apparatus for Treating Chloride Salt Wastes: System Evaluation and Scale-Up.

This paper describes an apparatus used to remove chlorine from chloride salt-based nuclear wastes from electrochemical reprocessing and/or chloride-based molten salt reactors (MSRs) through dechlorination by reacting the salts with ammonium dihydrogen phosphate (NHHPO or ADP) at temperatures up to 600 °C to produce NHCl as a byproduct. The benefits of removing the Cl from these salts include Cl recovery from Cl-based MSR salts, formation of UCl from the NHCl, as well as removal of Cl from the salts and conversion of the salt cations to oxides to allow for immobilization in a chemically durable iron phosphate waste form. This generation-2 system is an improvement over the generation-1 system and provides a means for scaling up salt throughput as well as NHCl recovery.

Ultralow Dispersion Multicomponent Thin-Film Chalcogenide Glass for Broadband Gradient-Index Optics.

A novel photothermal process to spatially modulate the concentration of sub-wavelength, high-index nanocrystals in a multicomponent Ge-As-Pb-Se chalcogenide glass thin film resulting in an optically functional infrared grating is demonstrated. The process results in the formation of an optical nanocomposite possessing ultralow dispersion over unprecedented bandwidth. The spatially tailored index and dispersion modification enables creation of arbitrary refractive index gradients.