Phase Equilibria of Uranium Trioxide and Aqueous Hydrofluoric Acid in Stoichiometric Concentrations¹

Phase Equilibria in Binary and Ternary Hydrothermal Systems

“…The existence of experimental evidences of two versions of immiscibility region of type d in the systems PbBr 2 - (Benrath et al, 1937), PbI 2 -H 2 O (Benrath et al, 1937;Valyashko and Urusova, 1996) and UO 2 F 2 -H 2 O (Marshall et al, 1954a), BaCl 2 -H 2 O (Valyashko et al, 1983). In the PbBr 2 -H 2 O, PbI 2 -H 2 O phase diagrams the stable immiscibility regions originate in solid saturated solutions L 1 -L 2 -G-S (point L), transform into three-phase equilibrium L 1 -L 2 -G and terminate in the critical endpoints R (L 1 = G-L 2 ) with increasing temperature.…”

“…(Schneider, 1978)); type 1b (2-butanol -H 2 O, 2-methylpyridine -D 2 O, 2-butanone -H 2 O (Schneider, 1978)); type 1b¢ (CO 2 -octane (Schneider, 1978), H 2 O -HgI 2 (Benrath et al, 1937;Valyashko and Urusova, 1996); type 1c¢ (CH 4 -1-hexene, CH 4 -2-methyl-1-pentene, CH 4 -3.3-dimethylpentane, CH 4 -2.3-dimethyl-1-buten (Schneider, 1978)); type 1d (CO 2 -nitrobenzene, CH 4 -hexane (Schneider, 1978), H 2 O -UO 2 SO 4 (Marshall and Gill, 1963;, H 2 ONa 2 B 4 O 7 (Urusova and Valyashko, 1990)); type 1d¢ (CH 4 -methylcyclopentane, CO 2 -hexadecane, CO 2 -H 2 O (Schneider, 1978), H 2 O -PbBr 2 , H 2 O -PbI 2 (Benrath et al, 1937;Valyashko and Urusova, 1996); type 1d≤ H 2 O -UO 2 F 2 (Marshall et al, 1954a)). …”

“…The system UO 2 F 2 -H 2 O [Marshall et al, 1954a] with some reservations can be related to type 1d≤, since the experimental studies are limited by temperature of the critical point "p" (L = G-S B ) and it is not clear whether or not there is the supercritical fl uid region at higher temperatures as in the case of type 2d≤ or this region is absent as in type 1d≤.…”

Verwendung von Uran als Kernbrennstoff

“…"Angepaßtes" Uranmetall mit 250 ppm Fe, 800 ppm AI, 350 ppm Si und 600 ppm C wurde im Reaktor CI R EN E (Schwerwasser-Druckwasser-Reaktor) in Italien als Brennstoff eingesetzt [18,19]. Bozzola u.a.…”

“…Bozzola u.a. [19] beschreiben Brennstäbe mit Zircaloy-2-Hüllen (11.4 mm Außendurchmesser, 0.64 mm oder 1.28 mm Wanddicke) und angepaßtem Uranmetall als Brennstoff. Ein innerer Hohlraum von 5%, 10% oder 20% des Volumens dient zur Aufnahme des Schwellens.…”