Go to ScienceDirect® Home Skip Main Navigation Links
 
Home
Browse
Search
My Settings
Alerts
Help
 Quick Search   Title, abstract, keywords   Author e.g.  j s smith
 Search tips (Opens new window)   Journal/book title   Volume   Issue   Page     Clear all fields    
Journal of Environmental Radioactivity
Volume 53, Issue 1, 2001, Pages 9-25

Abstract PDF (404 K)
Add to my quick links    Cited by    E-mail article    Save as citation alert    Export citation + link   
Abstract + References in Scopus
Cited By in Scopus (12)

doi:10.1016/S0265-931X(00)00100-4    How to Cite or Link Using DOI (Opens New Window)  
Copyright © 2000 Elsevier Science B.V. All rights reserved.

Size-fractionated plutonium isotopes in a coastal environment

M. H. DaiCorresponding Author Contact Information, E-mail The Corresponding Author, a, b, K. O. Buesselera, J. M. Kelleyc, J. E. Andrewsa, S. Pikea and J. F. Wackerc
a Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
b Ministry of Education, Marine Environmental Laboratory, Xiamen University, Xiamen, 361005, People's Republic of China
c Pacific Northwest National laboratory, PO Box 999, Richland, WA 99352, USA
Received 1 August 1999; revised 20 March 2000; accepted 25 March 2000. Available online 22 September 2000.



Abstract

We have examined the distribution of individual Pu isotopes (239Pu, 240Pu, and 241Pu) in seawater from the Gulf of Maine (GOM). Samples were size-fractionated with a 1 kD cross-flow ultrafiltration (CFF) membrane. Subfractioned samples were radiochemically purified and Pu isotopes were analyzed using a three-stage thermal ionization mass spectrometer (TIMS). To our knowledge, this is the first time that both size class and Pu isotopic data have been obtained for seawater samples. Within measurement uncertainties a single 240Pu/239Pu atom ratio of 0.18 was found for all sample collection depths and sample size fractions. This signifies a current, single Pu source in GOM waters, namely global fallout, and suggests that no measurable isotopic fractionation occurred during CFF processing. The majority of Pu was found in the low molecular weight fraction (<1 kD). Colloidal Pu varied from 8% of the total in surface waters to <1% in the deepest (250 m) seawater sample. Evidence suggests that the vertical distribution of Pu in GOM is primarily controlled by conservative mixing processes. The high Pu fraction found in the low molecular size fraction implies that most of the Pu is in the non-particle-reactive oxidized fraction, and is consistent with the conservative Pu behavior. The activity levels are in agreement with other studies which show a slow decrease in Pu with time due to continued mixing and relatively slow particle removal.

Author Keywords: Plutonium; Isotopes; Colloids; Cross-flow ultrafiltration; Gulf of Maine


Corresponding Author Contact Information Correspondence address: Clark 4, MS 25, WHOI, Woods Hole, MA 02543, USA. Tel.: +508-289-3466; fax: +508-457-2193; email: mdai@whoi.edu



Journal of Environmental Radioactivity
Volume 53, Issue 1, 2001, Pages 9-25
 
Home
Browse
Search
My Settings
Alerts
Help
Elsevier.com (Opens new window)
About ScienceDirect  |  Contact Us  |  Terms & Conditions  |  Privacy Policy
Copyright © 2007 Elsevier B.V. All rights reserved. ScienceDirect® is a registered trademark of Elsevier B.V.