Determination of tritium levels in tap waters collected from various regions in Thailand using liquid scintillation counting

Tritium can replace a hydrogen atom in water molecules since oxygen atom can react with tritium atoms to form water molecules the same way as for hydrogen atoms, potentially posing hazardous to consumers. This study aims to measure tritium activity concentrations in tap water samples collected from different regions in Thailand, (Phayao, Srisaket, Chanthaburi, Trang and Bangkok) in November 2018. The measurements of tritium activity concentrations were carried out by using electrolytic enrichment and low background liquid scintillation counting (AccuFLEX LSC-LB7), which had a sensitivity of less than 1 Bq/L. The data results of regional distribution of a tendency were discussed according to latitudes and longitudes of the collecting location. The measured tritium concentrations in tap water were in the range of 0.41 – 0.75 Bq/L. Specifically, the results showed that the tritium activity concentrations depended on location, with the highest value obtained from a tap water sample collected from the northern part of Thailand (Phayao). The results could be used as the baseline of tritium levels in tap water in each region of Thailand before building or operating the nuclear facilities such as the first nuclear power plant, fuel reprocessing or heavy water production facilities in the future. (paper)