title: Performance study and influence of radiation emission energy and soil contamination level on γ-radiation shielding of stabilised/solidified radionuclide-polluted soils.
abstract: This work focuses on the stabilisation/solidification (S/S) of radionuclide-polluted soils at different (232)Th levels using Portland cement alone and with barite aggregates. The potential of S/S was assessed applying a full testing protocol and calculating γ-radiation shielding (γRS) index, that included the measurement of soil radioactivity before and after the S/S as a function of the emission energy and soil contamination level. The results indicate that setting processes are strongly dependent on the contaminant concentration, and for contamination level higher than 5%, setting time values longer than 72 h. The addition of barite aggregates to the cement gout leads to a slight improvement of the S/S performance in terms of durability and contaminant leaching but reduces the mechanical resistance of the treated soils samples. Barite addition also causes an increase in the γ-rays shielding properties of the S/S treatment up to about 20%. Gamma-ray measurements show that γRS strongly depends on the energy, and that the radioactivity with the contamination level was governed by a linear trend, while, γRS index does not depend on the radionuclide concentration. Results allow the calculated γRS values and those available from other experiments to be applied to hazard radioactive soil contaminations.
authors.affiliation: Department of Civil Engineering and Architecture, University of Catania, Viale A. Doria, 6, 95125 Catania, Italy. Electronic address: ppfalci@dica.unict.it.
authors.forename: Pietro P
authors.initials: PP
authors.lastname: Falciglia
authors.affiliation: Department of Civil Engineering and Architecture, University of Catania, Viale A. Doria, 6, 95125 Catania, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Puccio
authors.affiliation: Laboratori Nazionali del Sud - INFN, Via S. Sofia, 62, 95125 Catania, Italy; Department of Physics and Astronomy, University of Catania, Viale A. Doria, 6, 95125 Catania, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Romano
authors.affiliation: Department of Civil Engineering and Architecture, University of Catania, Viale A. Doria, 6, 95125 Catania, Italy.
authors.forename: Federico G A
authors.initials: FGA
authors.lastname: Vagliasindi
mesh_terms: D001466:Barium Sulfate / Q000032:analysis*; D003252:Construction Materials / Q000032:analysis*; D005720:Gamma Rays; D011850:Radioactive Waste / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D064091:Waste Disposal Facilities; D018505:Waste Management / Q000379:methods*
chemical_list: D011850:Radioactive Waste; D012990:Soil Pollutants, Radioactive; D001466:Barium Sulfate
keywords: (232)Thorium ((232)Th); Energy emission; Radionuclides; Stabilisation/solidification; γ-Radiation shielding (γRS) index