>>64283660
Most of the dosimetry sources are very low energy and stored in protective containers, the more powerful ones used for scintillation spectrometry are the more dangerous ones which emit gamma even from their containment vessel so are stored in double the shielding. The one in your picture seems to be for a alpha emitting source due to the thinness and it wouldn't be soviet but western because the soviet sources are already partially decayed and useless for calibration. See pic related.