Md. Morehead et al., POTENTIAL RADIONUCLIDE TRANSPORT PATHWAYS FROM SEA-FLOOR DUMPSITES - KAMCHATKA REGION OF THE NORTH PACIFIC-OCEAN, Marine pollution bulletin, 35(7-12), 1997, pp. 353-364
Encapsulated nuclear waste materials, dumped by Russia, are present at
two deepwater seafloor locations in the offshore north-west Pacific O
cean, south-east of the Kamchatka Peninsula. This paper assesses poten
tial pathways by which these wastes might, if released from their cont
ainers, disperse away from the dumpsites and through the surrounding o
cean. A review of large-scale ocean circulation theory and of field an
d model results suggests that mean abyssal currents are north-eastward
to eastward from the dumpsite locations and would advect leaking mate
rials toward the north-eastern Pacific. Results of advective and diffu
sive horizontal plume transport models are consistent with this sense
of flow, Trajectory speeds are, however, subject to considerable uncer
tainty. Our results suggest that as little as 5 years or as long as 10
0 years might be required for material to be transported from the dump
sites to the north-east Pacific, Dilution by 4 or 5 orders of magnitu
de is predicted during this transit. Vertical mixing or upwelling are
necessary in order to transport contaminants upward from north-east Pa
cific abyssal waters to the near-surface layers before they can potent
ially impact productive coastal regions, such as those off Alaska. Inf
ormation concerning such upwelling mechanisms is inadequate for estima
tion of rates or to identify geographical areas that might be at risk,
(C) 1997 Elsevier Science Ltd. All rights reserved.