Natural background radiation at Lab 2 of Callio Lab, Pyhäsalmi mine in Finland

Characterization of natural radioactivity in the BSUIN and EUL underground laboratories based on the developed standard scheme

“…However, for the PH-500907 sample, it was 6.5 ± 0.7 mBq/L. The mean concentration of 238 U was 4.9 ± 0.7 mBq/L, 0.8 ± 0.2 mBq/L, and 11.1 ± 0.9 mBq/L for the PH-102, PH-103, and PH-500907 samples, respectively [4].…”

“…For concrete sample taken from the floor was 24.1 ± 1.5 Bq/kg and 25.8 ± 1.6 Bq/kg for 234 U and 238 U, respectively. On the other hand, the concentration of uranium isotopes for four rock samples taken from the corridor was on average 7.1 ±0.8 Bq/kg and 7.0 ± 0.5 Bq/kg for 234 U and 238 U, respectively [4].…”

“…The mean concentration of the 226 Ra isotope in the tested samples was: 116.6 ± 2.7 mBq/L, 15.1 ± 0.4 mBq/L, and 54.9 ± 1.3 mBq/L for PH-102, PH-103, and PH-500907, respectively. The mean concentration of the 228 Ra isotope was: 10.7 ± 4.5 mBq/L, 6.1 ± 0.9 mBq/L, and 36.0 ± 2.8 mBq/L for PH-102, PH-103, and PH-500907, respectively [4].…”

“…The agreement between measurements in laboratory conditions and Monte Carlo calculations at the level of a few percent was achieved. The thermal neutron measurement was 45.5 h, the average neutron counting rate was 14.78 ± 0.6, while the calculated neutron flux was (1.73 ± 0.10) × 10 −5 cm -2 s -1 [4].…”

“…The two water samples came from two pipes which collect the water seeping through the rocks behind Hall 2 of Lab 2 (PH-102 and PH-103), while the third sample was collected directly from the rock outside Lab 2 in its nearby (PH-500907) . Samples were taken directly into polyethylene bottles [4].…”