Reference material for natural radionuclides in glass designed for underground experiments

A reference material designed for the determination of natural radionuclides in solid samples (glass pellets) is described and the results of certification are presented. The material has been certified for 7 natural radionuclides ( 40 K, 226 Ra, 228 Ra, 228 Th, 232 Th, 235 U and 238 U). An information value is given for 210 Pb. Radon ( 222 Rn) emanation experiments showed results comparable within participating laboratories, however, the number of data and precision was too low to carry out a certification process. The reference material may be used for quality management of analytical laboratories engaged in the high-sensitive analysis of radionuclides in the construction materials of detectors placed in ultra low background underground laboratories.