Demonstration of Hollow Fiber Membrane Technique for the Recovery of Plutonium from Analytical Laboratory Waste

Abstract

Laboratory-scale studies were carried out to develop an analytical methodology for the processing of plutonium-bearing analytical laboratory waste at liter scale using hollow fiber–supported liquid membrane (HFSLM) technique by selective recovery of plutonium from uranium, americium, and other laboratory chemicals. In the first stage, uranium and plutonium were selectively transported from the feed to the receiver phase using 30% tri-n-butyl phosphate/n-dodecane which was used as the carrier in HFSLM. From the thus separated uranium and plutonium mixture, Pu(III) was selectively precipitated as ammonium plutonium(III)-oxalate [NH₄Pu(C₂O₄)₂ · 3H₂O], leaving most of the uranium in the supernatant solution. A combination of HFSLM method followed by ammonium plutonium–oxalate precipitation is faster, gives lower radiation exposure to working personnel, and generates lesser volume of secondary waste as compared to traditional precipitation/ion-exchange technique. Furthermore, the present methodology signifies its importance in providing a very good yield of Pu recovery (>99%) from waste solution.

Keywords:

• Hollow fiber–supported liquid membrane
• tri-n-butyl phosphate
• plutonium
• precipitation, separation

Acknowledgments

The authors are thankful to P. K. Pujari, associate director, RC&I Group of BARC, and S. Kannan, head, Fuel Chemistry Division, for their keen interest in this work.