Environmental tritium in the areas adjacent to Wolsong nuclear power plant

The distribution of environmental tritium and the correlation coefficients between tritium concentrations in several environmental samples and the emissions of tritiated water vapor from Wolsong NPP 1 were studied. The annual mean concentrations of atmospheric HTO were in the range 1•31–29•2 Bq m-3 and the long-term atmospheric dilution factors were in the range 10-7–10-6 s m-3. Annual mean concentrations of tritium in ground water were in the range 19•2–27•9 Bq l-1 at N-1 and 64•1–189 Bq l-1 at S-2, and were generally less than 0•2% of MPCw (222 kBq l-1). The concentrations of tritium in precipitation decreased exponentially with distance from Wolsong NPP 1, falling to current global levels at about 25 km off-site. The highest concentration of tritium in soil moisture was observed in May and June, when the relative humidity was high. The concentrations of tritium in soil moisture were higher than those in precipitation.