TRUEX flowsheet testing for the removal of the actinides from dissolved ICPP zirconium calcine using centrifugal contactors
Solid calcine is one of the wastes under evaluation for TRU removal by the TRUEX process. The calcine must first be dissolved in nitric acid prior to the removal of TRUs and fission products. Zirconium type calcine (generated from zirconium fuel reprocessing raffinates) comprises the majority of the calcine currently stored at the ICPP. The zirconium calcines average 18.3 wt% ZrO{sub 2} and are anticipated to be the most challenging to treat with regards to TRU removal because of the large zirconium content. This paper reports the results from a countercurrent flowsheet test performed with a dissolved calcine simulant in a 2-cm centrifugal contractor pilot plant. The simulant was spiked with radioactive {sup 241}Am and {sup 95}Zr to facilitate analysis and evaluate the behavior of the actinides. Flooding and precipitate formation were observed in the strip section during the flowsheet testing. It is postulated that the flooding occurred as a result of precipitate formation. The precipitate was determined to be ZrPO{sub 4} and was likely formed due the excessive amount of Zr carried into the strip section with the organic phase. Roughly 65% of the Zr in the feed was extracted. Of the extracted Zr, 15.6% reported to the strip product and 15.1% ended up in the organic effluent, indicating the strip section was ineffective at re-extracting Zr. The poor strip section performance was probably due to the precipitation and concomitant flooding problems encountered in the test, resulting in the strip section never achieving steady state operating conditions. Despite the obvious problems encountered during the test, > 99.18% of the americium was removed from the feed in the extraction section. This may be slightly lower than the anticipated 99.9% Am removal efficiency necessary to insure the < 10 nCi/g TRU content in the LLW raffinate.
- Research Organization:
- Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
- DOE Contract Number:
- AC07-94ID13223
- OSTI ID:
- 573171
- Report Number(s):
- INEEL/EXT-97-00837; ON: DE98052249; TRN: 98:009207
- Resource Relation:
- Other Information: PBD: Dec 1997
- Country of Publication:
- United States
- Language:
- English
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Baseline TRUEX Flowsheet Development for the Removal of the Actinides from Dissolved INTEC Calcine Using Centrifugal Contactors
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