Solvent Purex

S. B. Watson md R. H. Rmney, Modfcations of the SEPHIS Computer Code for Calculating the Purex Solvent Extraction System, ORNL/TM-5123, Oak Ridge National Laboratory, Oak Ridge, Term., 1975. 

Figure 11 Radiolysis products in Purex solvents (TBP, w-dodecane or kerosene, and HNO3). (From Ref. 137.)...

Dietz, M. L., Horwitz, E. P, Rogers, R. D., Extraction of strontium from acidic nitrate media using a modified purex solvent, Solv. Extr. Ion Exch., 13, 1-17,1995. 

Mitchell, A.D. 1979. SEPHIS-MOD4 A user s manual to revised model of the Purex solvent extraction system. ORNL-5471. 

The ZEALEX Process Researchers from KRI have shown that the zirconium salt of dibutyl phosphoric acid (ZS-HDBP) was soluble in Isopar-L in the presence of 30% TBP. This super PUREX solvent, known as ZEALEX, extracts actinides (Np-Am) together with lanthanides and other fission products, such as Ba, Cs, Fe, Mo, and Sr from nitric acid solutions. The extraction yields depend on both the molar ratio between Zr and HDBP in the 30% TBP/Isopar-L mixture and the concentration of HN03 (232). Trivalent transplutonium and lanthanide elements can be stripped together from the loaded ZEALEX solvent by a complexing solution, mixing ammonium carbonate, (NH4)2C03, and ethylenediamine-N.N.N. N -tetraacetic acid (EDTA). An optimized version of the process should allow the separation of... 

Horwitz, E.P., Kalina, D.G., Diamond, H Vandegrift, G.F., Schulz, W.W. The TRUEX process - a process for the extraction of the transuranic elements from nitric acid wastes utilizing modified Purex solvent. Solvent Extr. Ion Exch. (1985), 3 (1 2), 75-109. 

Flash point and fire point. An increase in irradiation leads to a lowering of the flash point and fire point of PUREX solvent (146). For example, after an absorbed dose of 300 W h L, the flash point of 30% TBP-dodecane was about 16°C lower than that of fresh solvent. 

To limit the radiolytic degradation of extractants, the influences of free-radical inhibitors have been measured. The addition of dimethoxybenzaldehydes (DMBA), particularly 3,5- and 3,4-DMBA, to the PUREX solvent could improve its stability and decrease its contamination (307). DMBA has a double effect, including a protective effect for the excited molecules of TBP (because of its low ionization potential), and the aldehyde radiolysis products could react with the HDBP present and therefore inhibit its complexing properties. 

Mailen, J.C. 1988. Secondary Purex solvent cleanup Laboratory development. Nucl. Technol. 83 182-189. 

Banko, K., Nowak, M. 1986. The effect of some aromatic aldehydes on stabilization of extractives properties of PUREX-solvent. Nukleonika 31(10-12) 325-343. 

Horwitz, E. P., D. G. Kalina, H. Diamond, et al. 1985. The TRUEX Process - A Process for the Extraction of the Transuranium Elements from Nitric Acid Wastes Utilizing Modified PUREX solvent. Solvent Extr. Ion Exch. 3, 75-109. 

Waste Compositions Selected for Study in the WFP. The major source of high-level wastes is the raflBnate or aqueous waste stream from the first cycle of the Purex solvent extraction process. The stream is a nitric acid solution containing over 99.9% of the nonvolatile fission... 

Large-scale purification of americium, curium, and californium with pressurized cation exchange has been planned at SRP for many years (1). Initial work involved SRP batch extractions to isolate a crude actinide-lanthanide fraction followed by solvent extraction and ion exchange in the SRL high level caves (1J. For large-scale purification, a single step was substituted for batch extraction and solvent extraction. Plant Purex solvent (30 vol % tri-n-butyl phosphate in n-paraffin) was used to minimize flush time and cross-contamination of solvent. 

Wymer, R.G. Vondra, B.L. PUREX solvent extraction chemistry. In Light Water Reactor Nuclear Fuel Cycle CRC Press, Inc. Boca Raton, FL, 1981 103-162. 

G6. Groenier, W. S. Calculation of the Transient Behavior of a Dilute-Purex Solvent... 

Hydrazoic acid HN3 is a volatile, potentially explosive compound, but it is extracted by Purex solvent and can be removed safely in the solvent wash system. 

Wagner, R M. Investigation of Explosive Characteristics of Purex Solvent Decomposition Products Red Oil, Report HW-27492, Mar. 1953. 

Geldard, J. and A. Beyerlein. 1985. PUBG PUREX solvent extraction process model. Report JkNL/ NESC-959. Argonne, IL Argonne national laboratory. 

Me Kibben, J.M. and J.E. Bercaw, 1971. Hydroxylamine nitrate as a plutonium reductant in the PUREX solvent extraction process. Report DP-1248. Aiken, SC Savannah River Laboratory. 

---