THE RADIOCHEMISTRY OF PLUTONIUM - Sciencemadness.org

Preparation of a - counting plates. An aliquot containing about 50 pg of U
was transferred to a stainless steel source tray in the usual manner. The micropipette
used was then washed three times with a solution of tetraethylene glycol (TEG) in dilute
nitric acid (4 drops of TEG in 10 ml of 1 ~ nitric acid). The solution on the source
tray was then evaporated to dryness under an infrared lamp and the disc was ignited
to redness. The evaporation must take place very slowly to avoid decomposition of
TEG by hot nitric acid. Two to three hours are necessary for the drying.
Separation procedure
(1) The aliquot, in 7-11 ~ nitric acid, was passed through a l-ml column
of 250-mesh Dowex 1 in the nitrate form to absorb tbe anionic Pu
nitrate complex.
(2) The uranium and fission products were washed through the column
with 20 ml of 7.5 ~ nitric acid. The strong acid was then displaced
with 1 ml of 1 M nitric acid.
.
(3) An aliquot of the effluent containing -40 mg of U was retained for U
isotopic analysis and the remainder was discarded.
(4) The Pu was eluted from the column with 4 ml of 1.0 ~ hydroxylamine
nitrate.
(5) The PU solution was extracted five times with 2 ml portions of 30%
TBP-soltrol to remove any U left with the Pu.
(6) The PU was precipitated from the aqueous phase with concentrated
ammonium hydroxide, dissolved in 100 k of concentrated nitric acid,
diluted to 0.5 rd and extracted with two O. 5-ml portions of 31)~0TBP-
soltrol.3
(7) The RI was then backwashes from the organic phase with 3 half-volume
1~ hydroxylamine nitrate washes, precipitated with ammonium hydro-
xide, washed once with water, and dissolved in 20 h of concentrated
nitric acid. The solution was then diluted to 1001 with 1 ~ nitric
acid.
3 The TBP extraction is necessary to separate the plutotium from resin decompo-
sition products.
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