In order to identify the concentration of tritium (3H) in areas of fresh, brackish and sea water, bordered by nuclear fuel facilities at Rokkasho-Village, Aomori, Japan, water
samples were collected from 2001 to 2004 at six points in those areas. Concentration ranges of tritium in fresh river water,
brackish lake and seawater samples were 0.60 to 1.1 Bq. l-1(mean value 0.79 Bq. l-1), 0.20 to 0.87 Bq. l-1(mean value 0.41 Bq. l-1), and 0.08 to 0.25 Bq. l-1(mean value 0.15 Bq. l-1), respectively. Relationships between tritium concentrations and salinity in the samples showed a clear negative correlation.
Moreover, the seasonal variation of tritium in water from Rokkasho-Village was high in spring and low in fall.