Sources of dissolved I-129 in brackish lake water during and after the operation of a spent nuclear fuel reprocessing plant

The contribution of four sources (river water, seawater, atmospheric deposition, and dissolution from sediment) to the I-129 concentration in water of a brackish lake which is adjacent to a nuclear fuel reprocessing plant in Northeast Japan was estimated using an observation dataset from 2006 to 2015, including the operation and non-operation terms of the plant (first three years: operation). The most major source of I-129 was the atmospheric deposition during and after the operation. However, the dissolution of sediment also became the significant source after the operation in summer because of the anoxic condition at the bottom of the lake.