Back to Main

Sediment pretreatment

• 0.25 g of sediment sample is weighed into a beaker
243Am and 242Pu yield determinant tracers are added (2-3 dpm)
• 15 ml of concentrated HNO3 and 5 ml of concentrated HCl is added and the mixture is gently heated on a hot plate for 2 h
• The solution is filtered through a glass fibre filter and the solution is evaporated to dryness

Separation of Pu and Am from U and Th

• The evaporation residue is dissolved in 10 ml of 3 M HNO3 + 1.0 M Al(NO3)3
• 2 ml of 0.6 M ferrous sulfamate is added and the solution is stirred (reduces Pu)
• 200 mg of ascorbic acid is added under stirring (Fe stays as Fe2+), waiting for 10 min., filtering if any solid matter
• UTEVA column is pretreated with 5 ml of 3 M HNO3
• The sample is loaded into the UTEVA column and the Pu and Am containing eluate is collected
• Rinse the beaker with 2x5 ml of 3 M HNO3 and pour the rinses to the column and collect the eluate in the beaker where the eluate above was collected

Separation of Plutonium and Americium from each other

• TRU column is pretreated with 5 ml of 2 M HNO3
• The sample collected from previous separation (UTEVA) is loaded into the TRU column
• The beaker is rinsed with 5 ml of 2 M HNO3 and added to the column
• The column is treated with 5 ml of 2 M HNO3 + 0.1 M NaNO2 (Pu is oxidized)
• The column is rinsed with 5 ml of 0.5 M HNO3
• Am is elute first with 3 ml of 9 M HCl and then with 20 ml of 4 M HCl
• The column is rinsed with 25 ml of 4 M HCl+0.1 M HF
• Pu is eluted with 10 ml of 0.02 M TiCl3 + 4 M HCl into Daniel tube

Co-precipitations for counting source preparations

• Am-bearing eluate is evaporated into dryness and again twice heated to dryness after addition of 3 ml of HCl + 1 ml of HNO3 to destroy residues of resin (heat aqua regia carefully!)
• Two additional heating to dryness will be made with a few milliliters of with concentrated HNO3. Am is then dissolved into 3 ml of 1 M HNO3 and poured in a Daniel tube, the beaker is rinsed with 2 ml of 1 M HNO3 and the rinses is added to the Daniel tube
• 0.5 ml of NdCl3 solution (0.1 g/l) carrier (50 µg of Nd) is added to Pu and Am solutions
• 0.6 (Am) and 1.0 (Pu) ml of concentrated HF is added to samples
• Samples are kept in a cold place at least for 30 min
• The Pu and Am -bearing NdF3 precipitate is filtered on 0.1µm filters in the following way:
  1. first 5 ml of water is added through the filter (to observe possible leakage of the filtering system)
  2. then 2 x 5 ml of NdCl3 solution (0.1 g/l) is added
  3. then the sample solution is added
  4. then the precipitation tubes are rinsed with 2 x 5 ml of water and poured onto the precipitate
  5. The filters are dried at room temperature for 0.5-1 hour and glued onto a plastic disc.
  6. The filters are measured for their Pu and Am activities with alpha spectrometry