[en] Short communication

[en] Three processes are discussed for separating tritium from gaseous and aqueous effluent systems: separation in the gas phase using Pd-25 wt percent Ag alloy diffusion membranes; electrolytic separation in the aqueous phase using ''bipolar'' electrodes; and the countercurrent exchange of tritium-containing hydrogen gas with water on catalytic surfaces combined with separation by direct electrolysis

[en] The history of the preparation of targets is summarized. The activities at different institutions, such as ORNL, Atomic Energy Commission, Central Bureau of Nuclear Measurements are highlighted. An annual international meeting has served as an important information interchange. The International Nuclear Target Development Society appears to have answered the need for technology, publication and information transmittal

No abstract available

No abstract available

[en] Because isotopes in metal form provide physicists with mononuclidic targets essentially void of extraneous or interfering nuclei in two-body experiments, conversions of compounds to metals warrant extensive study. Furthermore, having isotopes in pure metallic form permits (in many cases) physical manipulations to be performed so as to convert bulk material into suitable target configurations: thin foils, wires, castings, spheres, and even colloidal suspensions. Physical properties of metals are extensively influenced by small impurity concentrations; therefore, whatever conversion method is applied, it must preserve and/or create an ultrapure product. This paper discusses the application of the reduction of a solid compounded isotope, followed by metal distillation into a noncontaminating collector vessel. A variety of isotope metal vapor condensation-collection methods and subsequent treatment of the product to form various physical forms are discussed. Unfortunately, no single collection technique is applicable to all elements. Limitations of this technique with regard to reducible cations other than those noted earlier are discussed, together with the consequences of volatilization of some metal suboxides in this process. 11 figures

No abstract available

No abstract available

[en] Cermet materials are currently under investigation as an alternate for the primary containment of high level wastes. The cermet in this study is an iron--nickel base metal matrix containing uniformly dispersed, micron-size fission product oxides, aluminosilicates, and titanates. Cermets possess high thermal conductivity, and typical waste loading of 70 wt % with volume reduction factors of 2 to 200 and low processing volatility losses have been realized. Preliminary leach studies indicate a leach resistance comparable to other candidate waste forms; however, more quantitative data are required. Actual waste studies have begun on NFS Acid Thorex, SRP dried sludge and fresh, unneutralized SRP process wastes

[en] Cermets designed to isolate high-level wastes in a solid form are a composite consisting of various ceramic phase particles uniformly dispersed in and microencapsulated by an iron-nickel base alloy matrix. The metal matrix provides this waste form with many advantageous features including excellent thermal conductivity and mechanical strength. These cermets are formed by first dissolving the waste in molten urea, precipitating and calcining all the constituents, compacting the calcine, and sintering and reduction to form the final product. The exact formulation of cermets through additions to the waste is designed to fix most of the fission products in stable, leach resistant ceramic phases which are subsequently microencapsulated by an alloy matrix. The alloy matrix, which is derived primarily from the waste itself and includes the reducible fission and activation products from the waste, can be compositionally adjusted through additions to optimize its corrosion resistance under conditions existing in various disposal environments. The processes by which cermets are formed include several new and unique materials preparation options that are being developed to permit engineering scale-up and to be compatible with remote operations. Cermets formed by alternate processing methods are being characterized. Initially, cermet samples were prepared using a laboratory scale, batch process developed for the preparation of special ceramics having high compositional uniformity and excellent sinterability. The modification of this batch process to one suitable for scale-up and remote operation is the subject of this paper. Cermet characterization is also discussed