Chromium-51 as a Radioactive Tracer of Columbia River Water at Sea

Abstract

The plume of the Columbia River was followed 350 kilometers to sea by measurement of its chromium-51 content. This radioactive tag, introduced into the river by nuclear reactors at Hanford, Washington, promises to provide a useful oceanographic tool for determining rates of transport and mixing, and for identifying plume waters in the presence of other sources of fresh water.

Nutrient and phytoplankton dynamics in a coastal lagoon strongly affected by coastal upwelling

“…Furthermore, during the 1960s and up to 1971, the Columbia River estuary was a major source of radioactivity, carrying some 25,000 curies per month to the sea, due to the operation of nine plutonium reactors at Hanford. The radioactive plume could be clearly traced in the ocean 350 km to the southwest of the river mouth with 51 Cr (Osterberg et al, 1965). The half-life of 51 Cr is only 0.08 years, but some radioisotopes of large half-life (such as 6°C o) may have reached the sediments of San Quintin Bay.…”

“…Ademas, durante la dec ada de los sesenta y hasta 1971, el estuario del Rio Columbia fue una fuente mayor de radioactividad, transportando unos 25,000 curies por mesal mar, debido ala operacion de nueve reactores de plutonio en Hanford. La lengi.ieta radiactiva se podia trazar claramente en el oceano hasta 350 km al suroeste de la desembocadura del rio con 51 Cr (Osterberg et al, 1965). La vida media del 51 Cr es de tan solo 0.08 aiios, pero algunos radioisotopos de vida media larga (como el 6°C o) pueden haber llegado a los sedimentos de Bahia San Quintin.…”