Task 2.1: Ensuring traceability of the secondary thoron reference instruments used in the experimental research to the primary thoron measurement system at IRSN

The aim of this task is to calibrate the secondary thoron reference instruments used in the laboratories at IRSN, BEV-PTP, SUBG and STUK against the existing primary thoron measurement system at IRSN and thus to ensure traceability to the IRSN primary system of the thoron measurements made by the partners. These calibrated instruments will be used in Task 2.2 to investigate the influence of thoron on radon measurement devices.