Speciation of 137Cs and 90Sr in discharges from the pulp industry and the marine recipient

The concentrations and size distribution pattern of radionuclides in waste-water discharges from a pulp industry located at the Oslo fjord, Norway, have been studied. The annual discharge to the fjord amounts to about 1.9 GBq for 137Cs and 2.7 G Bq 90Sr. Information on the size-distribution pattern of 137Cs and 90Sr in discharge waste water and the marine recipient was obtained using tangential cross-flow ultrafiltration technique. Caesium-137 was measured with Ge-detectors, while 90Sr was determined using a low-level scintillation spectrometer. Almost all 137Cs in discharge waste water was found to be present in the low molecular weight fraction. The major fraction of 90Sr in discharge waste water was present in the low molecular weight fraction, while a significant fraction was found as colloids. Almost all 90Sr in seawater was present in the low molecular weight fraction. Due to transporting currents and dilution, no radiological impact on the receiving coastal waters could be observed.