NP-237 I-129 ATOM RATIOS IN THE ARCTIC-OCEAN - HAS NP-237 FROM WESTERN-EUROPEAN AND RUSSIAN FUEL-REPROCESSING FACILITIES ENTERED THE ARCTIC-OCEAN/

Radioactive waste discharges from European nuclear fuel reprocessing f acilities have introduced a suite of radionuclides (Sr-90, Tc-99, I-12 9, Cs-134, and Cs-137) into the Arctic Ocean by advection of North Atl antic water through the Norwegian Sea and Fram Strait. Measurements ma de in 1994 of Np-237 (T-1/2 = 2.14 x 10(6) year) and I-129 (T-1/2 = 15 .7 x 10(6) year) in surface waters (0-300 m) of the Arctic Ocean show a strong linear correlation in their concentrations below the Polar Mi xed Layer (30-50 m) indicating that Np-237 discharged from these same facilities (principally Sellafield) has entered the Arctic Ocean. Budg et calculations indicate that global fallout carried with runoff plus dischargers from Russian reprocessing facilities have contributed Np-2 37 to the upper Arctic Ocean in about equal proportions, but their com bined total is less than half that from Sellafield. Fallout from the C hernobyl accident added insignificant amounts of Np-237 and I-129 to t he Arctic Ocean compared to discharges from Sellafield and La Hague. ( C) 1998 Elsevier Science Ltd. All rights reserved.