Plutonium and americium in Lake Michigan sediments
The vertical distributions of $sup 239$$,$$sup 240$Pu, $sup 238$Pu, and $sup 137$Cs have been measured in sediment cores taken from Lake Michigan. Sections from a limited number of cores have been analyzed for $sup 241$Am. In addition, grab samples from ten locations in the southern basin of the lake have been analyzed for phase distribution of $sup 239$$,$$sup 240$Pu using a sequential extraction technique. The results indicate that the $sup 239$$,$$sup 240$Pu, $sup 238$Pu, and $sup 137$Cs from weapons testing, and the $sup 241$Am formed in situ are concentrated in the sediments. A comparison of the total deposition of $sup 239$$,$$sup 240$Pu and $sup 137$Cs indicates that $sup 137$Cs may be valuable as a monitor for $sup 239$$,$$sup 240$Pu deposition in the sediments. Values of the $sup 238$Pu/$sup 239$$,$$sup 240$Pu ratio are in agreement with values reported in Lake Ontario sediments (and Lake Michigan plankton) and show little variation with depth. $sup 241$Am data support the concept of in situ production with little preferential mobility after formation. Studies of sedimentary phase distributions show that $sup 239$$,$$sup 240$Pu is associated with hydrous oxide phases which are chemically stable under the prevailing conditions in lake sediments. Since Lake Michigan sediments remain aerobic, relatively little $sup 239$$,$$sup 240$Pu is available for chemical mobilization from the hydrous oxide or organic phases present in the sediments. (auth)
- Research Organization:
- Argonne National Lab., Ill. (USA)
- DOE Contract Number:
- W-31109-ENG-38
- NSA Number:
- NSA-33-009258
- OSTI ID:
- 4130003
- Report Number(s):
- CONF-751105--9; SM--199/47
- Country of Publication:
- United States
- Language:
- English
Similar Records
Plutonium and americum concentration along fresh water food chains of the Great Lakes, U. S. A. General summary of progress, 1975--1976
Distribution of plutonium in Lake Michigan sediments
Related Subjects
*CESIUM 137-- RADIATION MONITORING
*LAKE MICHIGAN-- RADIOECOLOGICAL CONCENTRATION
*PLUTONIUM 238-- RADIATION MONITORING
*PLUTONIUM 239-- RADIATION MONITORING
*PLUTONIUM 240-- RADIATION MONITORING
*SEDIMENTS-- RADIOACTIVITY
520300* --Environmental Sciences
Aquatic--Radioactive Materials Monitoring & Transport
N44300* --Environmental & Earth Sciences--Radioactivity Monitoring & Transport