Reference measurements of low levels of 60Co in steel

Analysis of 60Co traces in the matrix steel has recently gained in importance. This paper deals with the low-level γ-ray spectrometry measurements that were part of a recent German survey aiming at determining the present levels of artificial radionuclides in commercial steel. Specific 60Co activities in the order of 10−5 Bq g−1 were measured. To show equivalence in these measurements, a comparison exercise of European underground laboratories has been carried out, additionally.