A new nuclear fuel reprocessing method based on the anodic dissolution of s
pent fuels in aqueous alkaline solutions (Na2CO3-NaHCO3) has been proposed.
Experiments of the anodic dissolution were performed by using a simulated
spent fuel in a Na2CO3-NaHCO3 solution. Uranyl ions produced anodically wer
e present in the solution as stable carbonato complexes, and at the same ti
me, most of the simulated fission products (FP) were precipitated as hydrox
o or carbonate compounds. Under this condition, Cs of an alkali metal group
was dissolved in the solution and precipitated by adding sodium tetrapheny
lborate. Uranyl ion was recovered as hydroxo compounds by adding NaOH to th
e solution after removing precipitates of the simulated FP. In view of wast
e disposal, Tc-99 having a long half-life should be removed. Precipitation
behavior of Tc(VII) was examined by using Re(VII) as a simulant of Tc(VII).
It was found that Re(VII) species are completely removed as a precipitate
by adding tetraphenylphosphonium chloride. A large amount of Na used in the
present method was recovered as NaHCO3 by blowing CO2 into alkaline soluti
ons. As a result, it was clarified that the proposed method is fundamentall
y possible as a new reprocessing method.