Release of 3H and 14C during sampling and speciation in activated concrete

• Published in: Journal of radioanalytical and nuclear chemistry 2022, Vol.331 (2), p.859-865
• Main Authors: Leskinen, Anumaija, Hokkinen, Jouni, Kärkelä, Teemu, Kekki, Tommi
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Diagnostic Radiology; Hadrons; Heavy Ions; Inorganic Chemistry; Low temperature; Nuclear Chemistry; Nuclear Physics; Oxidation; Physical Chemistry; Radioisotopes; Sampling methods; Sampling techniques; Scintillation counters; Speciation
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-021-08144-6

Characterisation of contaminated and activated decommissioning waste require sampling of the studied material for the analysis of different radionuclides. The volatility of 3 H and 14 C can lead to the loss of the analytes in sampling of solid materials since most often at least some heat is involved in the sampling technique. Especially 3 H can be lost in cases when it is present as tritiated water (HTO) due to the evaporation of water even at low temperatures. Therefore, in this study, the 3 H and 14 C speciations are discussed. Consequently, a drilling sampling technique was developed in order to capture the released 3 H and 14 C in absorption solutions and measured using liquid scintillation counting. The sampling technique was tested on an activated concrete core. The collected samples were analysed for 3 H and 14 C (activity concentration and speciation) using a thermal oxidation technique. The results showed that a significant amount of 3 H was released during sampling even though the majority of 3 H was strongly bound in the activated concrete. The studied activated concrete did not contain measurable amount of 14 C and therefore speciation studies were not possible.