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| NKS Programme Area: | NKS-B | | Research Area: | Measurement Strategy, technology and QA | | Report Number: | EKO-1-R914-SV | | Report Title: | An intercomparison exercise on radionuclides in sediment samples | | Activity Acronym: | EKO-1 | | Authors: | Sven P. Nielsen | | Abstract: | An intercomparison exercise on artificial and natural radionuclides in two sediment
samples, one from the Baltic Sea and one from the Kattegat, has been carried out under
the EKO-1 project of the Nordic Safety Research Programme (NKS) for the period
1996-97. The measurement techniques have included direct gamma-ray spectrometry
with Ge and NaI detectors, and radiochemical procedures followed by beta counting
and alpha spectrometry. The participants have comprised 21 laboratories. Results
were submitted for Cs-137, Cs-134, Co-60, Sb-125, Pu-239,240, Pu-238, Am-241, Sr-
90, Ra-226, Th-232 and K-40, Pb-210, Po-210 and U-235. The analytical performance
of the participants was evaluated for those radionuclides where six or more data
sets were received. Statistical tests were made to see if individual results agreed with
overall average radionuclide concentrations in the two sediment materials within target
standard deviations. The results of these tests show that for Cs-137, Cs-134, Ra-
226, Th-232 and K-40 the analytical performance criteria were not met for 20-40% of
the data sets. For plutonium isotopes the tests show that the performance criteria were
not met for 13% of the data sets. Tests of overall analytical performance show that
61% of the data sets do not meet the combined performance criteria. This shows that
there is room for considerable improvement of analytical quality for most of the laboratories
that have participated in this intercomparison. The intercomparison exercise
has furthermore demonstrated several elementary problems in analytical work such as
interchange of samples, mistakes in calculations and correction of background levels. | | Publication date: | 01 Jul 1996 | | ISBN: | ISBN: 87-550-2227-8 | | Number of downloads: | 1768 | | Download: |  EKO-1-R914-SV.pdf |
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