Radionuclides in transport in the Columbia River from Pasco to Vancouver, Washington

The radionuclide discharges in the cooling-water effluent of the reactors on the U.S. Atomic Energy Reservation at Hanford, Wash., were formed by neutron activation of: (1) impurities in the Columbia River water used to cool the reactors, (2) corrosion products from the reactor components, and (3) chemicals used in the water-treatment process. Until all the eight reactors that were cooled by once-through flow were shut down, their cooling-water effluents were the main source of dissolved and particulate radionuclides in the Columbia River. Concentrations and discharges of 13 dissolved and particulate radionuclides were observed at Pasco and Vancouver, Wash., for all or parts of the period from January 1964 to September 1966, and at Umatilla, Oreg., from May 1965 to September 1966.