Comparison of 131 I activity measurements at the NCBJ RC POLATOM and the ENEA-INMRI linked to the BIPM SIR system.

A bilateral comparison between ENEA-INMRI (Italy) and NCBJ RC POLATOM (Poland) of 131 I-solution activity measurements was organized in the year 2015 and piloted by POLATOM, which provided the sources for the comparison. The 131 I master solution was standardized independently at both institutes by using Liquid Scintillation Counting and ionization chamber techniques. The 131 I master solution was then sent by POLATOM to the BIPM International Reference System (SIR). The comparison was registered as an EURAMET.RI(II)-K2.I-131 key comparison allowing the ENEA-INMRI result to enter in the SIR database.