Recovery of noble metals from HLLW using photocatalytic reduction

Conference · Thu Jan 01 04:00:00 EST 1987 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:6925936

Nishi, T; Uetake, N; Kawamura, F; Yusa, H

In high-level liquid waste (HLLW) from fuel reprocessing plants, noble metals (palladium, rhodium, and ruthenium), which account for approx. 10 wt% of fission products, exist as ions. These metals are very useful as catalytic material in automobile exhaust systems and other chemical processes, but they are rare in nature, making their recovery from fission products highly desirable. The ions of noble metals in solution have the feature that their reduction potential from ion to metal is relatively high compared with that of other fission product ions, so they can be selectively separated as a metal by a reduction process. The authors think a photoreduction process using a photocatalysts, which functions as photon-electron conversion agent, is suitable for the recovery of noble metals from HLLW for three reasons: (1) this process uses no reduction agents, which usually degrade the nitric acid, so that coprecipitation of other fission products does not occur. (2) The reactions are induced by light, which does not contaminate the reaction system, and in contrast with ordinary photo-redox reactions, the quantum yield is quite high. (3) As the photocatalyst does not change in the reaction, it can be used again and again. The report shows the results of fundamental experiments on the application of photocatalytic reduction to the recovery of noble metal ions in nitric acid solution.

• OSTI ID: 6925936
• Report Number(s): CONF-8711195-
• Conference Information: Journal Name: Trans. Am. Nucl. Soc.; (United States) Journal Volume: 55
• Country of Publication: United States
• Language: English

Related Subjects

052001 -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400703* -- Radiochemistry & Nuclear Chemistry-- Radioisotope Production
CHEMICAL REACTIONS
FISSION PRODUCTS
HIGH-LEVEL RADIOACTIVE WASTES
ISOTOPES
MANAGEMENT
MATERIALS
PALLADIUM ISOTOPES
PHOTOCHEMICAL REACTIONS
PROCESSING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTES
RECOVERY
REDUCTION
RHODIUM ISOTOPES
RUTHENIUM ISOTOPES
WASTE MANAGEMENT
WASTE PROCESSING
WASTES