Additional data for the deliverable "D1: Inter-laboratory comparison report for low-level radionuclide detection by mass spectrometry"

This dataset describes the results of an interlaboratory comparison exercise, focusing on comparing the capabilities of different mass spectrometers for low-level radioactivity measurement. Participating labs around Europe were asked to determine activity levels for a range of actinides (²³⁴U, ²³⁶U, ²³⁷Np, ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Am, NatU and ²³⁹/²⁴⁰Pu) and ⁹⁰Sr. Standards were prepared from starting materials at NPL through a series of dilutions using a dedicated source preparation facility and characterised for their activity per unit mass and impurities using a combination of decay counting and mass spectrometric techniques. Standards were distributed to participating laboratories along with a form for submitting the results and details of the measurements made. There were delays in sending of the materials to the participating laboratories, however, results were submitted for all radionuclides using multiple techniques. This provides valuable information on the capabilities of mass spectrometry for low-level radionuclide measurement and can inform the development of future standards and comparison exercises.