Application of a γRS index-based method and techno-economic analysis for in situ treatment of 137Cs-contaminated soils by cement-barite based stabilisation/solidification

Gamma ray spectrometer measurements indicate that γRS index increases with increasing barite percentage up to a maximum level of 50%; however a further increase results in a worsening of the shielding performances. A maximum γRS variation of 46.5% was recorded with grout percentage increasing from 16.6 to 50%. At the photon energy of 662 keV (137Cs), the maximum grout amount results in the possibility to shield up to 24.1% of γ-rays emitted. The effective dose reduction achievable by the investigated S/S allows a maximum 137Cs-soil contamination in the range 2.94-14.55 kBq kg−1 successfully treatable employing a soil: grout ratio of 1: 1 (C: Ba = 1:1). Technical data, jointly with economic analysis findings, make cement-barite based-S/S very competitive in cost-effectiveness and could provide a basis for decision-making of 137Cs-contaminated site remediation.