With the development of nulear power industry , more and more attention has been given to the spent nulear fuel reprocessing . purex process will remain predominant in the foreseenable future . because the valence of np , one kind of transuranium elements , is easy to interchange , the route of np in purex process is difficult to be controled . a lot of work has been done on the control of neptunium way in the world 随着核电的发展，乏燃料后处理引起了人们的广泛关注。 purex流程在乏燃料后处理中一直占有主导地位。由于超铀元素np的化学价态容易相互转变，使purex流程中np的走向不易控制而倾于分散。
