Mechanism of Plutonium Transport in a Shallow Aquifer in Mortandad Canyon, Los Alamos National Laboratory, New Mexico
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- 作者：Richard C. Marty ; Deborah Bennett ; and Philip Thullen
- 刊名：Environmental Science & Technology
- 出版年：1997
- 出版时间：July 1997
- 年：1997
- 卷：31
- 期：7
- 页码：2020 - 2027
- 全文大小：244K
- 年卷期：v.31,no.7(July 1997)
- ISSN：1520-5851
文摘
Potential environmental effects of radioactive isotopes areof great public concern. Fortunately most long-livedisotopes have strong affinities for solids and limitedmobilityunder natural conditions. It recently has beenproposedthat some isotopes may form colloids that move withgroundwater. The detection of plutonium ingroundwatersome 3400 m down Mortandad Canyon at the Los AlamosNational Laboratory is cited widely as an example of suchtransport. The current work re-examines data fromthiscanyon to evaluate the significance of such transport.239Pu entering the canyon increased sharply inthe early1980s. Routine monitoring during this period shows thatisotopically distinct plutonium appeared in one downgradientwell before it appeared in wells closer to the source.Ifthis is ignored, plutonium moved at least twice as fast asgroundwater flow and easily outdistanced a tritium peak.Isotopically heavy plutonium arrived simultaneously insurfacealluvium and groundwater, and the isotopic compositionof plutonium in alluvium and groundwater are identical.Plutonium clearly did not move down-canyon via groundwater. The potential for plutonium movement throughgroundwater on colloids may be overstated at this andother sites.