IMPROVEMENT OF ISOTOPIC COMPOSITION MEASUREMENTS OF PLUTONIUM BY THE USE OF CALIBRATION SAMPLES FOR GAMMA SPECTROMETRY
The PuO-2 pilot reference samples from CBNM Geel with isotopic compositions corresponding to different burn-up conditions (84, 70 and 61 % of 239-Pu) are almost infinite thick (> 99.9 %) for gamma rays up to 165 keV and allow thus the application of the enrichment meter technique for the determination of the isotope abundances by comparing the gamma peak intensities of the reference samples to those of sufficiently thick plutonium samples with unknown isotopic composition but with specified cladding conditions. The same reference samples have also shown to be helpful for complementary calibrations when high resolution gamma ray spectroscopy is used in conjunction with the intrinsic calibration technique in order to obtain isotope ratios of Pu and 241-Am. These complementary calibrations concern: + The testing and correction of the procedures for the determination of the overall relative efficiency curve for the lower energy gamma rays of interest. + The derivation of correction factors for the calculation of isotopic ratios from characteristic (preferentially close-lying) gamma lines. By this, subpercent accuracies for the determinations of Pu isotopic ratios are obtained for Pu samples of different burn-up and cladding conditions.
Bibliographic Reference: INTERNATIONAL SYMPOSIUM ON NUCLEAR MATERIAL SAFEGUARDS, WIEN (AUSTRIA), NOV. 10-14, 1986 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 32888 ORA
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Record Number: 1989125029500 / Last updated on: 1987-03-01
Available languages: en