The Scientific Basis for Long-Term Prediction of Waste-Form Performance Under Repository Conditions

1982 ◽  
Vol 15 ◽  
Author(s):  
John E. Mendel
Keyword(s):  
Nuclear Waste ◽  
Waste Disposal ◽  
Scientific Basis ◽  
Future Generations ◽  
Waste Form ◽  
Flow Paths ◽  
Performance Requirements ◽  
Long Term Prediction ◽  
The Impact

The reason for making long-term predictions of waste-form performance under repository conditions is to assess the impact of nuclear waste disposal upon the safety of future generations. Assessment of repository safety can be approached in two ways. One method is to define an acceptable release of radioactivity to the accessible environment, and to work back from that point to determine what kind of performance requirements are placed on the waste form. When this is done, it is found that the performance requirements for the waste form are not very restrictive. The waste form can dissolve completely in 100 to 10,000 years without affecting safety [1,2], because the repositories will be 300 meters or more underground. Radionuclide retardation on repository rocks and overburden and dilution during the long flow paths to the accessible environment become the controlling parameters.

Materials Interactions Relating to Long-Term Geologic Disposal of Nuclear Waste Glass

1986 ◽  
Vol 84 ◽  
Author(s):  
Ned E. Bibler ◽  
Carol M. Jantzen
Keyword(s):  
Nuclear Waste ◽  
Review Paper ◽  
Waste Glass ◽  
Waste Form ◽  
Glass Waste ◽  
Waste Package ◽  
Geologic Disposal ◽  
Nuclear Waste Glass ◽  
Backfill Materials

AbstractIn the geologic disposal of nuclear waste glass, the glass will eventually interact with groundwater in the repository system. Interactions can also occur between the glass and other waste package materials that are present. These include the steel canister that holds the glass, the metal overpack over the canister, backfill materials that may be used, and the repository host rock. This review paper systematizes the additional interactions that materials in the waste package will impose on the borosilicate glass waste form-groundwater interactions. The repository geologies reviewed are tuff, salt, basalt, and granite. The interactions emphasized are those appropriate to conditions expected after repository closure, e.g. oxic vs. anoxic conditions. Whenever possible, the effect of radiation from the waste form on the interactions is examined. The interactions are evaluated based on their effect on the release and speciation of various elements including radionuclides from the glass. It is noted when further tests of repository interactions are needed before long-term predictions can be made.

Monitoring deep subsurface microbiota for assessment of safe long-term nuclear waste disposal

1996 ◽  
Vol 42 (4) ◽  
pp. 375-381 ◽  
Author(s):  
David C. White ◽  
David B. Ringelberg
Keyword(s):  
Nuclear Waste ◽  
Waste Disposal ◽  
Nuclear Waste Disposal ◽  
Physiological Status ◽  
Deep Subsurface ◽  
Long Term Storage ◽  
Lipid Biomarker ◽  
Potential Problems

Microbes with their resistance to heat and radioactivity, if present and metabolically active, could have major effects on the safety of nuclear waste disposal by posing potential problems in long-term containment. This paper reviews the applicability of the signature lipid biomarker (SLB) analysis in the quantitative assessment of the viable biomass, community composition, and nutritional/physiological status of the subsurface microbiota as it exists in situ in subsurface samples. The samples described in this review are not unlike those expected to be recovered from proposed deep subsurface disposal sites. Assessment of the microbial community ecology using SLB analysis can be utilized to predict potential problems engendered by microbial metabolic activities of these communities in breaching containment by microbially facilitated corrosion and in the potential for subsequent facilitated transport of nuclides into the environment. SLB analysis of the in situ microbial ecology can be utilized to monitor the feasibility of containment options in modeling tests at the specific disposal sites.Key words: nuclear waste, deep subsurface, microbiota, microbial corrosion, safe long-term storage, signature lipid biomarkers.

Natural Analogues: Their Application to the Prediction of the Long-Term Behavior of Nuclear Waste Forms

1986 ◽  
Vol 84 ◽  
Author(s):  
Rodney C. Ewing ◽  
Michael J. Jercinovic
Keyword(s):  
Nuclear Waste ◽  
Borosilicate Glass ◽  
Large Scale ◽  
Laboratory Data ◽  
Waste Form ◽  
Long Time ◽  
Natural Analogues ◽  
Long Term Behavior ◽  
Nuclear Waste Forms

AbstractOne of the unique and scientifically most difficult aspects of nuclear waste isolation is the extrapolation ofshot-term laboratory data (hours to years) to the long time periods (103-105 years) required by regulatory agencies for performance assessment. The direct verification of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural analogues of both the repository environment (e.g. radionuclide migration at Oklo) and nuclear waste form behavior (e.g. alteration of basaltic glasses and radiation damage in minerals) have been used to demonstrate the long-term behavior of large scale geologic systems and, on a smaller scale, waste form durability. This paper reviews the use of natural analogues to predict the long-term behavior of nuclear waste form glasses. Particular emphasis is placed on the inherent limitations of any conclusions that are based on “proof” by analogy. An example -- corrosion of borosilicate glass -- is discussed in detail with specific attention to the proper and successful use of natural analogues (basaltic glass) in understanding the long-term corrosion behavior of borosilicate glass.

Evaluation of the Localised Corrosion of Carbon Steel Overpacks for Nuclear Waste Disposal in Granite Environments

1985 ◽  
Vol 50 ◽  
Author(s):  
G. P. Marsh ◽  
K. J. Taylor ◽  
I. D. Bland ◽  
C. Westcott ◽  
P. W. Tasker ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Mathematical Modelling ◽  
Nuclear Waste ◽  
Waste Disposal ◽  
Experimental Approach ◽  
Steel Corrosion ◽  
Spent Fuel ◽  
Corrosion Attack ◽  
Metal Thickness

AbstractThe application of carbon steel corrosion allowance containers for the long term encapsulation of HLW or spent fuel requires data on the likely rates of corrosion attack so that the metal thickness needed to prevent penetration can be estimated. This paper describes a joint mathematical modelling and experimental approach to the evaluation of the rate of localised corrosion.

Impact of microbial activity on the radioactive waste disposal: long term prediction of biocorrosion processes

2014 ◽  
Vol 97 ◽  
pp. 162-168 ◽  
Author(s):  
Marie Libert ◽  
Marta Kerber Schütz ◽  
Loïc Esnault ◽  
Damien Féron ◽  
Olivier Bildstein
Keyword(s):  
Radioactive Waste ◽  
Microbial Activity ◽  
Waste Disposal ◽  
Radioactive Waste Disposal ◽  
Term Prediction ◽  
Long Term Prediction
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