Actinides recovery

Gray, L. W. Radke, J. H., in "Actinide Recovery from Waste... 

Bray, L. A. Ryan, J. L. in "Actinide Recovery From Waste... 

Mullins, L.J. Christensen, D.C. Babcock, B.R. "Fused Salt Processing of Impure Plutonium Dioxide to High Purity Metal", Los Alamos Nat. Lab. Report LA-9154-MS also Symposium on Actinide Recovery from Waste and Low Grade Sources, ACS, New York City August 23-28, 1981 (in press). 

Adnet, J.M., Miguirditchian, M., Hill, C. et al. 2005. Development of new hydromet-allurgical processes for actinide recovery GANEX concept. Proc GLOBAL 2005, Tsukuba, Japan, October 9-13. Paper No. 119. 

Fujii, T., Yamana, H., Moriyama, H. 2002. Decontamination study of some noticeable fission products in the actinides recovery by TRUEX process. 7th Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation, October, Jeju, Republic of Korea. 

Nakahara, M., Sano, Y., Koma, Y., Kamiya, M., Shibata, A., Koizumi, T., Koyama, T. 2005. Actinides recovery by solvent extraction in NEXT process. Global 2005 Nuclear Energy System for Future Generation and Global Sustainability, October, Tsukuba, Japan. 

During the aging of the HLLW solution from a Purex plant insoluble precipitates are known to form, which could endanger the operation of any actinide recovery process and increase actinide losses. It is therefore believed that an actinide separation process must use the HLLW solution as soon as possible after it is... 

Membrane technology may become essential if zero-discharge mills become a requirement or legislation on water use becomes very restrictive. The type of membrane fractionation required varies according to the use that is to be made of the treated water. This issue is addressed in Chapter 35, which describes the apphcation of membrane processes in the pulp and paper industry for treatment of the effluent generated. Chapter 36 focuses on the apphcation of membrane bioreactors in wastewater treatment. Chapter 37 describes the apphcations of hollow fiber contactors in membrane-assisted solvent extraction for the recovery of metallic pollutants. The apphcations of membrane contactors in the treatment of gaseous waste streams are presented in Chapter 38. Chapter 39 deals with an important development in the strip dispersion technique for actinide recovery/metal separation. Chapter 40 focuses on electrically enhanced membrane separation and catalysis. Chapter 41 contains important case studies on the treatment of effluent in the leather industry. The case studies cover the work carried out at pilot plant level with membrane bioreactors and reverse osmosis. Development in nanofiltration and a case study on the recovery of impurity-free sodium thiocyanate in the acrylic industry are described in Chapter 42. 

Gupta, SK. Actinides Recovery Using Membrane Based Extraction Technique, MSc thesis (Research), University of Mumbai, 2003. Gupta, SK. et al. Non-dispersive extraction of Am(III) using PC-88A as an extractant, at DAE Symposium on Nuclear and Radiochemistry (NUCAR-2003) BARC Trombay, Mumbai, February 10-13, p. 133, 2003. 

Table III. Composition of High-Level Waste from Reprocessing LWR Fuel, and Actinide Recovery Factors Required"...

The purpose of this Symposium has been to bring together information concerning actinide recovery, partition, and purification on an international basis from various disciplines and viewpoints. The result of this interchange, it is hoped, will be to spark ideas for improvement and development of new separation techniques and methods for all aspects of actinide technology. 

Each process step is being investigated for fission product behavior and distribution with respect to the desired actinide recovery. The effect of added constituents on the behavior of actinide and fission-product compounds in molten nitrates will be studied. Soluble species in molten nitrates are to be identified and a determination made as to whether fission product elements are present, either as soluble species or solids, as anionic or cationic species. 

Choose processing systems that complement each other and provide actinide recovery opportunities in depth. 

Actinide Recovery Area. Both WTFs require an Actinide Recovery Area where actinides are recovered from the liquors being produced in the above-mentioned treatment areas. The WTF supporting the fuel reprocessing plant (see Figure 3) requires both a TBP and CMP extraction cycle, but the WTF supporting the fuel refabrication plant can be operated with a CMP extraction cycle alone and by utilizing the existing, on-site TBP scrap recovery system. 

Solvent Cleanup and Recycle. Both TBP and CMP solvents can be cleaned up with simple water and dilute sodium carbonate washes. The conceptual flowsheets also include preequilibration of the solvents with acid before they are recycled to the extraction columns. This treatment helps to maintain high acid concentrations in the extraction column raffinates. For the CMP extractant, equilibration with high acid also helps to strip the ruthenate and pertechnetate anions from the solvent. Activity levels in the Actinide Recovery Area are further controlled by bleeding a fraction of its CMP solvent to the CMP Solvent Recycle... 

Gel-type cation exchange resins were therefore compared with a macroporous resin for the recovery of plutonium and americium from molten salt residues. The effects on actinide recovery of loading and eluting in the downflow mode, and loading in the upflow, eluting in the downflow mode were also determined. 

Seven ion exchange tests were made in the downflow loading and elution mode. The amount of actinides fed to the column and the percent actinide recovery obtained with 4.2 column volumes of 7M HNO3 elutriant are shown in Table II. 

Type of Resin MSE Waste Actinide in Feed Actinide Recovery+... 

As a result of this preliminary work it was concluded that the increased actinide capacity, faster elution kinetics, and better decontamination properties of macroporous resins justify additional work to further evaluate Bio-Rad AG MP-50 and other macroporous resins for the MSE cation process macroporous resins do appear to be better for actinide recovery from molten salt residues than gel-type resins. 

Only three of many commercially available resins were tested in this preliminary work. Other macroporous resins will be tested. Loading and elution kinetics, breakthrough capacities, actinide recovery and radiation stability will be evaluated for candidate resins. 

---