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Title: Role of Microbes as Biocolloids in the Transport of Actinides from a Deep Underground Radioactive Waste Repository

Role of Microbes as Biocolloids in the Transport of Actinides from a Deep Underground Radioactive Waste Repository We investigated the interaction of dissolved actinides Th, U, Np Zgpu, and Am, with a pure and a mixed culture of halophilic bactezia isolated from the Waste Isolation H.Iot Plant repository under anaerobic conditions to evaluate their potentiaI transport as biocolloids from the waste site. The sizes of the bacterial cells studied ranged from ().54 x 0.48 pm to 7.7 x 0.67pm Using sequential mimofiltration, we determined the ~~ation of actinides with fi-ee-living (mobile) bacterial cells suspended in a fluid medium containing. NaCl or M=W12 brine, at various phaes of their growth cycIes. The number of suspended kcteria rangy-d born 106 to 109 cells ml-*. Tine amount of actinide associatd with the wspend~ cell fraction (cakzdated & mol cell-*) was very Iow: Th, 10-*2; U, 10-1s - 10-lS; - ~ Np, 1o-15- 10-19; Pu, 10-ls -10-21 ; and h, 10-1* - 10-*9 ; and it varied with the bacteihl - CUIture studied. l%e differe&es in the asswiation are amibuted to the extent of bioamxmdation and biosorption by the bacteria pH, the compo&on of the brine, and the speziation and bioavaiIability of the actinides.
Authors: ; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:2439
Report Number(s):SAND98-0370J
ON: DE00002439
DOE Contract Number:AC04-94AL85000
Resource Type:Journal Article
Data Type:
Resource Relation:Journal Name: Radiochemeca Acta
Research Org:Sandia National Laboratories, Albuquerque, NM, and Livermore, CA
Sponsoring Org:USDOE
Country of Publication:United States
Language:English
Subject: 05 NUCLEAR FUELS; 55 BIOLOGY AND MEDICINE, BASIC STUDIES; Microorganisms; Microorganisms; Actinides; Actinides; Radioactive Wastes; Radioactive Wastes