Recent Developments In Nuclear Fuel Reprocessing

摘要

PUREX process employing TBP as extractant has been successfully ensiloyed for the commercial production of Pu from the spent fuels emanating from variety of thermal reactors. Radiochemists and Nuclear Technologists have met the challenges presented due to the limitations of TBP with distinction. Continuous improvements in the D.F. values, the quantitative recoveries of Pu and U and the reduction in the waste volumes have been accomplished due to their R&D efforts. There is however only a limited experience in therecovery of ~(233)U using THOREX process. Nuclear Industry has to prepare itself for the new challenges of reprocessing spent fuels discharged from Pu based fast reactor fuels or Th based advanced heavy water reactor fuels. Existing processes may have to be further modified to meet the demands of larger Pu content; larger radiation damage to the solvent, larger inventory of fission products and above all the complex situation of dealing with a Th-Pu-U based ternary system. In view of its excellent track record, TBP continues to be the prime choice of separation scientists and technologists. However, large secondary waste volumes are a cause of concern to the waste management personnel. As the stake in the success of reprocessing programme is high, there is a need to develop alternate extractants, which are efficient, versatile and are environmentally friendly. N, N dialkyl amides are potential candidates to be explored towards this end. Advanced reprocessing incorporating actinide partitioning is a major innovation aimed at reducing the cost of disposal and surveillance of high-level liquid waste. It will help a great deal in achieving better public understanding and acceptance of nuclear energy programmes all around the world.