Reference

Use of a method for the selective dissolution of zirconium and titanium during the study of corrosion processes

Use of a method for the selective dissolution of zirconium and titanium during the study of corrosion processes. Polyak, E. A.; Yut, M. K.; Rodionova, L. A. (Sverdl. Nauchno-Issled. Inst. Khim. Mashinostr., Sverdlovsk, USSR). Zh. Prikl. Khim. (Leningrad), 50(3), 678-80 (Russian) 1977. CODEN: ZPKHAB. DOCUMENT TYPE: Journal CA Section: 56 (Nonferrous Metals and Alloys) The selective dissoln. of metallic Zr or Ti in a solvent of citric acid [77-92-9] and NH4F [12125-01-8] was employed to study the high-temp. oxidn. and the corrosion of these metals in molten phosphates. The metallic matrix of Zr or Ti dissolves completely in the solvent with a F--to-citric ion ratio 3:1, whereas oxides remain undissolved. Thus, the corrosion of Zr held for 5 h in molten Na metaphosphate at 800.degree. was 30.5 g/m2, whereas that in metaphosphoric acid at 500.degree. was 9.1 g/m2. The P1/P2 values (P1 and P2 are the O contents in the oxide film and metallic matrix, resp.) after holding Zr in air at 600 and 800.degree. were 7.0 and 2.2, resp.

Flowsheets [for Zircaloy conversion to inert mass]

Flowsheets [for Zircaloy conversion to inert mass]. Kearsey, H. A.; Mercer, A. C. (UK). Comm. Eur. Communities, [Rep.] EUR, EUR 9363, Convers. Zircaloy Massive Chem. Inert Form, 195-220 (English) 1985. CODEN: CECED9. DOCUMENT TYPE: Report CA Section: 71 (Nuclear Technology) Section cross-reference(s): 56 A block diagram of the overall process for the conversion of Zircaloy [12742-60-8] to a massive inert form, showing the alternative immobilization routes is given. The immobilization process options considered are: (a) hot-pressing following countercurrent washing; (b) hot-pressing following dewatering of the washed zirconia; (c) incorporation with cement following countercurrent washing; and (d) incorporation into cement of unwashed hydrous zirconia. Although the same basic stages are used for conversion to oxide, the need to reduce the fluoride content of the oxide to different levels affects the quantity of recycled NH4F [12125-01-8] and therefore sep. flowsheets are required for each option. Each flowsheet is based on a PWR fuel reprocessing plant to facilitate the iterative calcns. required due to the recycle of the NH4F soln., a computer program was written for a CBM 8032 microcomputer which can be used to produce a detailed flowsheet for any required process option.