Counter current studies on actinide partitioning from sulphate bearing simulated high level waste using CMPO

摘要: High level wastes< HLW> arising from fuel reprocessing plants contain small quantities of actinides like plutonium, uranium and americium in addition to fission products. Removal of these ace in idea prior to vitrification of HLW can effectively reduce the active surveillance period. Counter current studies using indigeneously synthesised octyl (phenyl)-N, N-diisobutylcarbamoylmethylphosphine o:< ide (CP1PQ) were taken up as a follow up of successful batch extraction and stripping of actinides from high active waste (HAW) and high level waste (HLW) concentrates. Simulated HLW of equivalent composition was used in these experiments. After an initial uranium removal step using a four stage mixer settler, the raffinate was spiked with plutonium, americium and fission product activities. For extraction and stripping of actinides, a six stag* mixer settler was used. A mixture of 0.2 M CMPO and 1.2 M TBP in dodecane was used as the extractant. Complete extraction of uranium, plutonium and americium was achieved in six stages. Almost 1OOJ4 of cerium and 61% of ruthenium were also extracted. Stripping of americium was about 60% by 0.04 M HN09. Almost 100% of plutonium and all residual americium could be stripped by 0.01 MH2c20* from the loaded organic phase. Na2CO3 stripped uranium and residual fission product activities completely and made the organic phase suitable for recycle. These runs proved the process feasibility for removal of actinides from HLW to near background level.70 Keywords/Descriptors: URANIUM; PLUTONIUM; AMERICIUM; RUTHENIUM; HIGH-LEVEL RADIOACTIVE WASTES; COUNTER CURRENT …