A new large-volume metal reference standard for radioactive waste management

A new large volume metal reference standard has been developed. The intended use is for calibration of free release radioactivity measurement systems and is made up of cast iron tubes placed inside a box of the size of a Euro-pallet (80×120 cm2). The tubes contain certified activity concentrations of 60Co, (0.290±0.005) Bq/g, and 110mAg (3.05±0.06) Bq/g (Reference date: September 30, 2013). They were produced using centrifugal casting from a smelt into which 60Co was first added and then one piece of neutron irradiated silver wire was progressively diluted. The iron castings were machined to the desirable dimensions. The final material consists of 12 iron tubes of 20 cm outer diameter, 17.6 cm inner diameter, 40 cm length/height and 245.9 kg total mass. This paper describes the reference standard and the process of obtaining the reference activity values.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

The CCRI(II)-K2.Fe-55.2019 key comparison of activity concentration measurements of a 55^{55}Fe solution

International audienceA comparison of the activity concentration of an 55 Fe solution was organized by the POLATOM under the auspices of the CCRI(II). The solution was sent to thirteen laboratories; ready-to-measure sources were also prepared using the same 55 Fe solution in diffusive (polyethylene) vials and sent to twelve laboratories. Twelve measurement reports were received. The results, as well as relevant information on the measurement techniques, are presented and analysed in this paper. The differences in the results obtained from measurements in non-diffusive (glass) and diffusive vials are indicated. To reach the main text of this paper, click on Final Report . Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/ . The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA)

Results of an international comparison of activity measurements of 68 Ge

Proceedings of the 21st International Conference on Radionuclide Metrology and its Applications (ICRM), May 15-19, 2017, Buenos Aires, Argentina. Organizer: Argentinian National Atomic Energy CommissionInternational audienceAn international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11) kBq g−1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6 mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence