A new certified reference material IAEA-465 for radionuclides in Baltic Sea sediment.

Certified reference material (CRM) for natural (K,Pb,Po,Ra,Ra,Th,Th,Th,U,U, andU) and anthropogenic (Cs,Pu, andAm) radionuclides in marine sediment from the Baltic Sea (IAEA-465) has been developed. Information values are given for Pu,Pu andPu. Altogether 27 laboratories participated in this exercise.

Intercomparison exercises as a tool for improving the quality of radiochemical measurements in drinking waters - Radon-222 determinations.

The results of a European intercomparison on Rn in water were analyzed to evaluate the performances of standard and non-standard methods. Then, results obtained with a specific LSC method (ISO 13164-4) based on two-phase liquid scintillation counting which has been employed by a considerable number of participants were examined in detail. This ISO LSC method was proved to be accurate, reliable and its reproducibility has been also sufficient.

Performance evaluation of a European wide proficiency test on gross alpha/beta activity determination in drinking water.

JRC-Geel organised a Europe-wide proficiency test on gross alpha/beta activity concentration measurements in water with 154 participants from the field of environmental radioactivity monitoring. The performance of the participants was evaluated by comparing their results to the reference value using percentage deviation, z-score and zeta-score. Many of the participants' results deviated several orders of magnitude from the reference values regardless of the techniques used suggesting that the radioactivity monitoring of drinking water using gross-counting in Europe needs improving.

Performance evaluation of a European scale proficiency test on radon-in-water measurements in Europe.

In 2018, a Europe wide proficiency test (PT) on measurements of the massic activity of Rn in drinking water was organised with the participation of 101 European environmental radioactivity monitoring laboratories. The performance of the participating laboratories was evaluated by comparing submitted results to the reference value using percentage deviation, z-score and zeta-score. It was found that 84% of the participants' results were within the ±20% reference range.

Alpha-particle emission probabilities of Pa derived from first semiconductor spectrometric measurements.

The nuclide Pa is a member of the U decay chain. It is a complex alpha emitter with 25 identified alpha emissions. Formerly published alpha-particle emission probabilities were derived from measurements taken with magnetic spectrometers.