European measurement comparison of <Superscript>137</Superscript>Cs, <Superscript>40</Superscript>K and <Superscript>90</Superscript>Sr in milk powder

Recently, the Institute for Reference Materials and Measurements (IRMM) has assumed responsibility for organizing regular measurement comparisons among those laboratories which provide radioactivity monitoring data from their country to authorities of the European Commission (EC) under various EC legislation articles. The most recent exercise under this International Comparison Scheme for Radioactivity Environmental Monitoring (ICS-REM) in measuring the ¹³⁷Cs, ⁴⁰K and the ⁹⁰Sr activity concentration in milk powder is presented here. The complete cycle of the comparison is described, including the establishment of reference values traceable to SI units, the demonstration of the homogeneity of the distributed samples, the treatment and measurement of samples in the participating laboratories, and the evaluation of the results.     

Characterization of the NIST shellfish Standard Reference Material 4358

A new shellfish Standard Reference Material 4358 was developed by the National Institute of Standards and Technology through an international interlaboratory comparison that involved twelve laboratories-participants from nine countries. The results from the participants were statistically evaluated, and the most robust certified values were based on the median of laboratories’ reported means and the uncertainties derived using the bootstrap method. Massic activity certified values were established for fourteen radionuclides, five activity ratios, and informational massic activity values for eight more radionuclides and two activity ratios.     

Standardisation of 241Am activity for a key comparison

Journal of Radioanalytical and Nuclear Chemistry - The JRC applied six measurement techniques to standardise the activity of an 241Am solution in the frame of the 2003 key comparison...     

Current radioactivity content of wild edible mushrooms: A candidate for an environmental reference material

The paper presents the results of radiological investigation of several mushroom samples collected in the fall of 2004 in different parts of Europe. The work was performed in order to support decision making to develop and produce a certified reference material for quality assurance of radionuclide measurements in environmental samples. The levels of ¹³⁷Cs in mushrooms varied widely ranging from 0.6 to 4300 Bq/kg on dry mass basis, while those of natural ⁴⁰K were relatively constant. In one sample ⁶⁰Co of unknown origin was detected (25±2 Bq/kg dry mass), while ⁹⁰Sr concentrations were usually below the detection limit (<150 mBq/kg dry mass).