T03_P11
Simple method for analyses of total radiocarbon in water samples using wet chemical oxidation at HEKAL AMS Laboratory
Molnár A1,2, Molnár M1,3, Veres M2, Czébely A2, Rinyu L2,3, Rozmanitz P4, Janovics R2,3
1University of Debrecen, Doctoral School of Physics, Debrecen, Hungary, 2Isotoptech Zrt., Debrecen, Hungary, 3INTERACT Centre, Institute for Nuclear Research, Debrecen, Hungary, 4Paks Nuclear Power Plant, Paks, Hungary
The ¹⁴C is the one of the most important radionuclides released from the nuclear facilities to the environment. Currently, the inorganic ¹⁴C is checked during regular environmental monitoring as part of the groundwater monitoring programme of the Paks Nuclear Power Plant.
One of disadvantages of the only inorganic carbon determination is that the DIC concentration has a significant dilution effect by the natural radiocarbon content of the groundwater on any discharged pollution surrounding the power plant.
For this reason, a wet oxidation method was developed for AMS ¹⁴C measurement technique to determine the ¹⁴C activity concentration of the total dissolved carbon content of water samples, coming from environmental monitoring wells. The typical ¹⁴C background is (1-2 pMC) obtained by preparation of blank samples, which allows a detection level of around 5·10-5 Bq L-1. The activity of the organic fraction can be calculated using the formula presented in the study. The method was applied for water samples deriving from environmental monitoring wells around Paks Nuclear Power Plant (pressurized-water reactors (PWR)). The results of our investigations over the 14 different water samples around the Paks NPP show that DO¹⁴C contribution to the total ¹⁴C activity concentration was between 5-25%.
The elaborated method may be useful mostly upon the environmental monitoring analyses of nuclear facilities and radioactive waste disposal facilities, as with the help of this method, the total radiocarbon activity of groundwater can be determined as easily, as the commonly applied DI¹⁴C analyses.