Joint Recovery of f-Elements Using Solvent Based on Carbamoyl-phosphine Oxides Heading Toward ORGA-Process
- 4002 Narita-cho, Japan Atomic Energy Agency, O-arai-machi, Ibaraki-ken, Post No. 311-1393 (Japan)
- 2nd Murinsky Avenue, RPA V.G.Khlopin Radium Institute, 194021, Saint-Petersburg, 28 (Russian Federation)
Development of the recovery system which allows realizing joint recovery of all the actinides from the HLW is one of the relevant questions in radiochemistry. Carbamoyl-phosphine oxides (CMPO) were proposed and studied as extractant for rare-earth and transplutonium elements (RE and TPE) recovery from HLW with high acidity, for example TRUEX- and SETFICS-process. Organic system CMPO with TBP in kerosene is usually used as a solvent. However, low solubility of actinide adducts with CMPO results in third phase formation when the actinides concentration in organic phase is high. Application of fluorinated polar diluents increases the solubility of CMPO adducts with actinides in organic phase. It was shown that solvent based on carbamoyl-phosphonate in fluorinated polar diluents allows to recover both uranium and minor actinides concurrently, and there was no precipitation or third phase formation even at high uranium concentration in organic phase. The f-elements joint recovery process based on this solvent was proposed. Solvent containing octyl-phenyl-N,N-di-isobutyl-carbamoyl-methylene-phosphine oxide (O{phi}D[iB]CMPO) in polar diluent meta-nitro-benzo-trifluoride (fluoro-pole-732) was screened out for these studies. And, combined use of them with TBP modifier allows to provide uranium and europium (americium) high recovery characteristics concurrently with an opportunity of attainment of f-elements high concentration in organic phase. As it was indicated, precipitates or third phase was absent even when uranium content in organic phase was 100 g/l. Recovery efficiency to europium remained sufficiently high for its effective recovery. Organic phase saturation about 100% from theoretical attains in europium recovery with this system. Increasing of (O{phi}D[iB]CMPO) concentration in recovery system from 0.2 to 0.8 M results in europium content increasing in organic phase, but no third phase formation is observed. The highest possible europium content in organic phase is about 30 g/l for system with 0.2 M O{phi}D[iB]CMPO and 60- 65 g/l for system with 0.8 M O{phi}D[iB]CMPO. Proposed mixture solvent can be used in joint recovery of all f-elements directly from the dissolver solution of nuclear spent fuel - ORGA-process (abbreviation of Organo-phosphoryl-fluoro-pole solvent for Recovery of Group of Actinides). The ORGA flowsheet is expected to be highly proliferation-resistant, because TRU group and U will separately be recovered by proposed aqueous, salt-free complexants. (authors)
- Research Organization:
- American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
- OSTI ID:
- 20979670
- Resource Relation:
- Conference: Advanced nuclear fuel cycles and systems (GLOBAL 2007), Boise - Idaho (United States), 9-13 Sep 2007; Other Information: Country of input: France; 9 refs; Related Information: In: Proceedings of GLOBAL 2007 conference on advanced nuclear fuel cycles and systems, 1873 pages.
- Country of Publication:
- United States
- Language:
- English
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