Quantitative assessment of microbiological contributions to corrosion of candidate nuclear waste-package materials
The U.S. Department of Energy is contributing to the design of a potential nuclear-waste repository at Yucca Mountain, Nevada. A system to predict the contribution of Yucca Mountain (YM) bacteria to overall corrosion rates of candidate waste-package (WP) materials was designed and implemented. DC linear polarization resistance techniques were applied to candidate material coupons that had been inoculated with a mixture of YM-derived bacteria with potentially corrosive activities or left sterile. Inoculated bacteria caused a 5- to 6-fold increase in corrosion rate of carbon steel C1020 (to approximately 7Ð8mm/yr) and an almost 100-fold increase in corrosion rate of Alloy 400 (to approximately 1mm/yr). Microbiologically influenced corrosion (MIC) rates on more resistant materials (CRMs: Alloy 625, Type 304 Stainless Steel, and Alloy C22) were on the order of hundredths of micrometers per year (mm/yr). Bulk chemical and surfacial end-point analyses of spent media and coupon surfaces showed preferential dissolution of nickel from Alloy 400 coupons and depletion of chromium from CRMs after incubation with YM bacteria. Scanning electron microscopy (SEM) also showed greater damage to the Alloy 400 surface than that indicated by electrochemical detection methods.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Civilian Radioactive Waste Management (RW)
- DOE Contract Number:
- W-7405-Eng-48
- OSTI ID:
- 3398
- Report Number(s):
- UCRL-JC-131555; ON: DE00003398
- Resource Relation:
- Conference: Materials Research Society Fall Meeting (MRS 98) Scientific Basis for Nuclear Waste Management XXII, Boston, MA, November 30-December 4, 1998
- Country of Publication:
- United States
- Language:
- English
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