CHEMICAL PROCEDURES AND COUNTING TECHNIQUES
i i itil
Strontium-90
is separated by the fuming nitric acid precipitation
and then purified through hydroxides and chromates precipitations,
The activity of the final strontium carbonate and yttrium oxalate
precipitates is measured in low level anticoincidence beta counters,
Cesium-137 is measured by direct gamma spectrometry on the unprocessed or dried samples and, whenever it is necessary, by
gamma spectrometry after chemical separation. This is performed ©
by filtration of the solution, obtained dissolving the sample, through
a thin AMP (ammonium molybdophosphate) layer, by which cesium
is retained,
Details of this procedure may be found in the paper
by E. Van der Stricht issued ‘on "Radiochemical Acta" 3, 193-199
(1964),
Gamma emitting nuclides
are measured by direct gamma spectro~
metry, using, also the spectrum stripping technique.
is separated by anion exchange and electro-
deposition; details of the procedure may be found in the paper by
M.C. de Bortoli: "Radiochemical determination of plutonium in
soil and other environmental samples", Anal, Chem, 39, 375
(March 1967).
The activity is measured in a Frish grid ionisation chamber connected to a multichannel analyser,
Oe AE pe UHI, TMI ie ARR RRC
Plutonium-239+240
_EXTRAPOLATION OF THE DATA
extrapolated to the last day of the collecting period,
peg
are
samen yum dag ee
Except when otherwise stated, the data presented in this report
TII
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