Hostname: page-component-848d4c4894-x5gtn Total loading time: 0 Render date: 2024-05-10T01:44:28.432Z Has data issue: false hasContentIssue false

A Procedure to Evaluate the Potential for Microbially Influenced Degradation of Cement-Solidified Low-Level Radioactive Waste Forms

Published online by Cambridge University Press:  15 February 2011

R. D. Rogers
Affiliation:
Idaho National Engineering Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-2203
M. A. Hamilton
Affiliation:
Idaho National Engineering Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-2203
R. H. Veeh
Affiliation:
Idaho National Engineering Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-2203
J. W. Mcconnell Jr.
Affiliation:
Idaho National Engineering Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-2203
Get access

Abstract

Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. An environmentally mediated process that could affect cement stability is the action of naturally occurring microorganisms. The U.S. Nuclear Regulatory Commission (NRC), recognizing this eventuality, stated in their Technical Position on Waste Form, Revision 1, that the effects of microbial action on waste form integrity must be addressed. This paper provides recent results from a program that examined the effects of microbially influenced degradation (MID) on cement-solidified LLW. Data are provided which were obtained during the development of an evaluation method using acid-producing bacteria. Results presented here are from work with one type of these bacteria, the sulfur-oxidizing Thiobacillus. Commercially prepared, cement-solidified, low-level radioactive waste form samples made from power reactor wastes were evaluated using a new biodegradation test developed for the NRC. Testing demonstrated that MID has the potential to severely compromise the structural integrity and nuclide retentiveness of ion-exchange resin and evaporator-bottoms wastes that have been solidified with cement. It was found that the waste form specimens physically deteriorated after 60 days of exposure to the thiobacilli. Also, the data show that significant amounts of Cs-137, Cs-134, Co-60, C-14, Tc-99, and Sr-90 contained in the waste forms were leached in the presence of Thiobacillus.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Rogers, R.D., Hamilton, M.A., and McConnell, J.W. Jr. in The Possibility for Microbially Influenced Degradation of Cement Solidified Low-Level Radioactive Waste Forms, edited by Interrante, C.G. and Pabalan, R.T. (Mater. Res. Soc. Proc. 294, Boston, MA 1993), pp. 261266.Google Scholar
2. Nuclear Regulatory Commission, Technical Position on Waste Form, Rev. 1, Low-Level Waste Management Branch, Washington, D.C., January 1991.Google Scholar
3. Nuclear Regulatory Commission, Proceedings of the Workshop on Cement Stabilization of Low-Level Radioactive Waste, NRC publication NUREG/CR-0103 (1989).Google Scholar
4. Rogers, R.D., Hamilton, M.A., and McConnell, J.W. Jr. in Development of Methodology to Evaluate Microbially Influenced Degradation of Cement-Solidified Low-Level Radioactive Waste Forms, edited by Barkatt, A. and Konynenburg, R.A. Van (Mater. Res. Soc. Proc. 333, Boston, MA 1994), pp. 349356.Google Scholar
5. Francis, A.J., Dobbs, S., and Nine, R.J., “Microbial Activity of Trench Leachates from Shallowland Low-level Radioactive Waste Disposal Sites,” App. of Environ. Micro. 40, pp. 108113 (1980).Google Scholar
6. Rogers, R.D. and McConnell, J.W. Jr., Biodegradation Testing of TMI-2 EPICOR-II Waste Forms, NRC publication NUREG/CR-5137 (1988).Google Scholar
7. Rogers, R.D., Hamilton, M.A., Veeh, R.H., and McConnell, J.W. Jr., Microbial Degradation of Low-Level Radioactive Waste, Annual Report for FY 1994, NRC publication NUREG/CR-6188, Vol.2 (1994).Google Scholar
8. Sand, W. and Bock, E., “Biogenic Sulfuric Acid Attack in Sewage Systems,” in Seventh International Biodeterioration Symposium: Cambridge, England, edited by Houghton, D.R., Smith, R.N., and Eggins, H.O.W., pp. 113117 (1988).Google Scholar
9. Islander, R.L., Devinny, J.S., Mansfeld, R., Postyn, A., and Shih, H., “Microbial Ecology of Crown Corrosion in Sewers,” J. Env. Eng. 26, pp. 751770 (1991).Google Scholar
10. Mori, T., Nonada, T., Tazake, K., Koga, M., Hikosaka, Y., and Hoda, S., “Interactions of Nutrients, Moisture, and pH on Microbial Corrosion of Concrete Sewer Pipes,” Water Resources Research 26, pp. 2937 (1992).Google Scholar