The originally proposed removal process for strontium and transuranic speci
es from 241-AN-102 and 241-AN-107 Hanford waste tank supernates was a co-pr
ecipitation method. In initial testing, the slurry formed during the stront
ium and ferric nitrate co-precipitant additions was not filterable. A serie
s of statistically designed tests were performed to evaluate the variables
responsible for this poor filterability. These tests also explored strategi
es to improve the associated decontamination efficiency of the treatment pr
ocess. These tests revealed that filterability is negatively influenced by
ferric ion added to co-precipitate actinide and lanthanide species. The con
centrations of sodium and organic complexants were observed to influence de
contamination of the supernate. Furthermore, the amount of at least one org
anic complexant was correlated to the poor filterability. The americium dec
ontamination factors measured following the maximum iron nitrate addition w
ere marginal at levels of precipitant addition that are of practical intere
st. Based on these results, alternative precipitation schemes were investig
ated. Reported here is the chosen replacement process, a permanganate preci
pitation process. A statistically designed series of experiments examined t
he relationship between three responses and five precipitation parameters.
The three responses are precipitate filterability, strontium decontaminatio
n, and plutonium decontamination. The parameters varied were the initial so
dium and hydroxide concentrations of the waste, and the amount of calcium,
strontium, and permanganate introduced. The results reveal an optimum set o
f conditions for decontamination of strontium and plutonium as well as impr
oved filterability.