Enumeration of microbial populations in radioactive environments by epifluorescence microscopy
- and others
Epifluorescence microscopy was utilized to enumerate halophilic bacterial populations in two studies involving inoculated, actual waste/brine mixtures and pure brine solutions. The studies include an initial set of experiments designed to elucidate potential transformations of actinide-containing wastes under salt-repository conditions, including microbially mediated changes. The first study included periodic enumeration of bacterial populations of a mixed inoculum initially added to a collection of test containers. The contents of the test containers are the different types of actual radioactive waste that could potentially be stored in nuclear waste repositories in a salt environment. The transuranic waste was generated from materials used in actinide laboratory research. The results show that cell numbers decreased with time. Sorption of the bacteria to solid surfaces in the test system is discussed as a possible mechanism for the decrease in cell numbers. The second study was designed to determine radiological and/or chemical effects of {sup 239}Pu, {sup 243}Am, {sup 237}Np, {sup 232}Th and {sup 238}U on the growth of pure and mixed anaerobic, denitrifying bacterial cultures in brine media. Pu, Am, and Np isotopes at concentrations of {le}1x10{sup -6} M , {le}5x10{sup -6} M and {le}5x10{sup -4}M respectively, and Th and U isotopes {le}4x10{sup -3}M were tested in these media. The results indicate that high concentrations of certain actinides affected both the bacterial growth rate and morphology. However, relatively minor effects from Am were observed at all tested concentrations with the pure culture.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 459916
- Report Number(s):
- BNL-64029; CONF-961201-102; ON: DE97004072; TRN: 97:007843
- Resource Relation:
- Conference: 82. scientific assembly and annual meeting of the Radiological Society of North America (RSNA) and the American Association of Physicists in Medicine, Chicago, IL (United States), 1-6 Dec 1996; Other Information: PBD: Jan 1997
- Country of Publication:
- United States
- Language:
- English
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