Plutonium and americium in anoxic marine sediments: Evidence against remobitization

Computer Science

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

4

Scientific paper

239 + 240 Pu activities of 100-450dpm/kg are found down to 15-18 cm in anoxic Saanich Inlet sediments, with a subsurface maximum in undisturbed deposits. Integrated 239 + 240 Pu inventories which overlap delivery estimates are present both in two cores of anoxic sediments from Saanich Inlet and in one core of oxic sediments 65 km away in Dabob Bay, Washington. 241 Am / 239 + 240 Pu ratios in Saanich Inlet sediments overlap ratios in unfractionated midnorthern latitude fallout, in oxic sediments from the Washington continental shelf, and in anoxic sediments from two basins off southern California and Mexico. The 239 + 240 Pu / 137 Cs ratios in three intervals of Saanich Inlet sediments are also in agreement with ratios previously reported for oxic coastal marine sediments. The Pu inventories, the Am / Pu and Pu / Cs ratios, and the Saanich Inlet Dabob Bay comparison all argue that Pu is not rapidly remobilized in anoxic sediments. The subsurface 239 + 240 Pu activity maximum is not in agreement with the historical record of peak Pu fallout in 1963-1964 unless our 210 Pb-derived sedimentation rates are incorrectly high. However, they are in good agreement with previous 210 Pb and varve chronologies in Saanich Inlet, and also give reasonable dates for times when 239 + 240 Pu and SNAP-9A supplied 238 Pu first appear in the sediments. We conclude they properly date the maximum in sedimentary 239 + 240 Pu activity at 1970-1973, and seek explanations for the 7-10yr time lag after peak fallout. 239 + 240 Pu inventories in one core from the eastern basin of the Cariaco Trench and in two cores from Golfo Dulce. an anoxic basin off the Pacific coast of Costa Rica, are also in reasonable agreement with fallout delivery to these latitudes when excess 210 Pb inventories and fluxes are used to verify recovery of at least a major fraction of the most recently deposited sediments.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Plutonium and americium in anoxic marine sediments: Evidence against remobitization does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Plutonium and americium in anoxic marine sediments: Evidence against remobitization, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plutonium and americium in anoxic marine sediments: Evidence against remobitization will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1469204

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.