Remote examination of radioactive wastes using γ-ray spectrometry

Abstract

Places of location of some γ-ray sources on the site for temporary storage of solid radioactive wastes of SevRAO OF-2 Federal State Unitary Enterprise (Gremikha settlement, Murmansk oblast, Russia) were determined using a procedure for remote determination of radiation source coordinates with a Cartogam γ-imaging system. The γ-ray spectra from these radiation sources were recorded using the remote procedure with an ISOCS spectrometric complex. In particular, the isotope composition of γ-active containers Bet8, TK113, L18, and L20 was determined. The main technogenic γ-radiation from these objects is associated with the decay of ¹³⁷Cs and, to a lesser extent, with the decay of ⁶⁰Co, ¹⁵²Eu, and ¹⁵⁴Eu. For the Bet8 container, its activity content was estimated (∼10¹⁴ Bq). The dependence of the specific activity of the soil surface layer in the guard zone in front of the waste storage site on the distance from the site was determined with a 7 m step. The specific activity considerably decreases with an increase in the distance from the site (from 15–28 kBq kg⁻¹ at a distance of 3 m to 1–2.8 kBq kg⁻¹ at a distance of 10–24 m).