Long Term Field Leaching Studies of Simulated Nuclear Waste Glass in Granite and Salt

1991 ◽  
Vol 257 ◽  
Author(s):  
R.L. Schulz ◽  
D.E. Clark ◽  
A.R. Lodding ◽  
G.G. Wicks
Keyword(s):  
New Mexico ◽  
Nuclear Waste ◽  
Waste Isolation Pilot Plant ◽  
Study Results ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Interaction Test ◽  
Glass Compositions ◽  
Term Field

ABSTRACTField leaching studies were carried out in granite at the Stripa site in Sweden and also in salt in the Materials Interface Interaction Test at the Waste Isolation Pilot Plant (MIIT/WIPP) in New Mexico. The goal of these studies is to assess the durability of various glass compositions engineered to isolate high-level nuclear waste from the biosphere. An additional goal of the MIIT study is to determine how the glasses interact with a wide array of proposed materials that may be a part of the multi-barrier waste package. These substances include metals, geological host specimens,, as well as engineered backfill and overpack materials.Two year data on the SRLY (165/TDS) glass compositions has been extracted from both studies (Stripa and WIPP/MIIT) and five year data has recently become available from the MIIT study. Results from SEM/EDS, SIMS and FTIRRS analyses on glass/glass interfaces are presented in this paper.

Comparison of Granite, Tuff, and Basalt as Geologic Media for Long-Term Storage of High-Level Nuclear Waste

1990 ◽  
Vol 212 ◽  
Author(s):  
D. E. Grandstaff ◽  
V. J. Grassi ◽  
A. C. Lee ◽  
G. C. Ulmer
Keyword(s):  
Nuclear Waste ◽  
Nuclear Waste Repository ◽  
Long Term Storage ◽  
Hydrothermal Experiments ◽  
Ion Activity ◽  
Activity Ratios ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Term Storage

ABSTRACTSystematic differences in pH, cation/proton ion activity ratios, and redox have been observed between solutions produced in rock-water hydrothermal experiments with tuff, granite, and basalt. Stable pH values in tuff-water experiments may be as much as 1.5 pH units more acidic than basalt-water experiments at the same temperature and ionic strength. Redox (log fO2) values in 300°C tuff experiments are 4–7 orders of magnitude more oxidizing than basalt experiments and ca. 4 log units more oxidizing than the magnetite-hematite buffer. Such fluid differences could significantly affect the performance of a high-level nuclear waste repository and should be considered in repository design and siting.

Nepheline Crystallization in High-Alumina High-Level Waste Glass

2015 ◽  
Vol 1744 ◽  
pp. 85-91 ◽  
Author(s):  
José Marcial ◽  
John McCloy ◽  
Owen Neill
Keyword(s):  
Nuclear Waste ◽  
Waste Glass ◽  
High Alumina ◽  
High Level Waste ◽  
Interfacial Conditions ◽  
Waste Vitrification ◽  
Cooling Schedules ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Glass Compositions

ABSTRACTThe understanding of the crystallization of aluminosilicate phases in nuclear waste glasses is a major challenge for nuclear waste vitrification. Robust studies on the compositional dependence of nepheline formation have focused on large compositional spaces with hundreds of glass compositions. However, there are clear benefits to obtaining complete descriptions of the conditions under which crystallization occurs for specific glasses, adding to the understanding of nucleation and growth kinetics and interfacial conditions. The focus of this work was the investigation of the microstructure and composition of one simulant high-level nuclear waste glass crystallized under isothermal and continuous cooling schedules. It was observed that conditions of low undercooling, nepheline was the most abundant aluminosilicate phase. Further undercooling led to the formation of additional phases such as calcium phosphate. Nepheline composition was independent of thermal history.

scholarly journals Transporting and Storing High-Level Nuclear Waste in the U.S.—Insights from a Mathematical Model

2019 ◽  
Vol 9 (12) ◽  
pp. 2437 ◽  
Author(s):  
Sebastian Wegel ◽  
Victoria Czempinski ◽  
Pao-Yu Oei ◽  
Ben Wealer
Keyword(s):  
Nuclear Waste ◽  
The United States ◽  
Nuclear Industry ◽  
High Level Waste ◽  
Geological Repository ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Interim Storage ◽  
Storage Facilities

The nuclear industry in the United States of America has accumulated about 70,000 metric tons of high-level nuclear waste over the past decades; at present, this waste is temporarily stored close to the nuclear power plants. The industry and the Department of Energy are now facing two related challenges: (i) will a permanent geological repository, e.g., Yucca Mountain, become available in the future, and if yes, when?; (ii) should the high-level waste be transported to interim storage facilities in the meantime, which may be safer and more cost economic? This paper presents a mathematical transportation model that evaluates the economic challenges and costs associated with different scenarios regarding the opening of a long-term geological repository. The model results suggest that any further delay in opening a long-term storage increases cost and consolidated interim storage facilities should be built now. We show that Yucca Mountain’s capacity is insufficient and additional storage is necessary. A sensitivity analysis for the reprocessing of high-level waste finds this uneconomic in all cases. This paper thus emphasizes the urgency of dealing with the high-level nuclear waste and informs the debate between the nuclear industry and policymakers on the basis of objective data and quantitative analysis.

Creep of the copper canister in the Swedish program

2006 ◽  
Vol 932 ◽  
Author(s):  
William H Bowyer
Keyword(s):  
Nuclear Waste ◽  
Strengthening Mechanism ◽  
Test Results ◽  
Short Life ◽  
Iron Load ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Life Predictions ◽  
Good Agreement

ABSTRACTThe Swedish programme for disposal of high level nuclear waste includes the development of a container which comprises a cast iron load bearing canister contained in a 50 mm thick copper corrosionshield.The temperature of the outside of the canister is likely be up to 100°C, and repository processes may lead to long term loads of up to 50MPa. Creep of the copper is therefore an issue. SKB (The Swedish Nuclear Fuel and Waste Management Co.) have been conducted tests on three materials, OF copper containing 10ppm sulphur (OF1), OF copper containing 6ppm sulphur (OF2) and OF copper containing 6ppm sulphur and 50ppm phosphorus (OFP). In order to improve confidence in extrapolation of test results to practical temperatures and stresses, it is desirable to support the extrapolation procedures with a physical model.Life predictions made using the Frost and Ashby model [5] together with a simplification of the Cocksand Ashby model [6] provide good agreement with published experimental data for OF2 and OFPmaterials. Extrapolation of this data using the model leads to life predictions of 12,000 years for the OF2material and 120,000 years for OFP material. The prediction for OFP depends on an assumption that an observed strengthening mechanism conferred by phosphorus at high stresses and temperatures, is equally as effective under repository conditions.OF1 material fails after a relatively short life and by a different mechanism to OF2 and OFP. The changein mechanism may be explained, using the model [6], for cases where segregating species reduce surface energy of grain boundary voids. It is suggested that in this case the segregating species is sulphur.

scholarly journals Science and Licensing: Let's Get off the Collision Course

1993 ◽  
Vol 333 ◽  
Author(s):  
R. A. Van Konynenburg
Keyword(s):  
Nuclear Waste ◽  
Waste Disposal ◽  
Scientific Method ◽  
Scientific Evidence ◽  
Limiting Factors ◽  
Future Behavior ◽  
Scientific Approach ◽  
High Level Nuclear Waste ◽  
High Level

ABSTRACTThe best possibility for gaining an understanding of the likely future behavior of a high level nuclear waste disposal system is use of the scientific method. However, the scientific approach has inherent limitations when it comes to making long-term predictions with confidence. This paper examines these limiting factors as well as the criteria for admissibility of scientific evidence in the legal arena, and concludes that the prospects are doubtful for successful licensing of a potential repository under the regulations that were binding until recently. Suggestions are made for remedying this situation.

Non-Linearity in Glass Composition Dependence of Dissolution Rates: Effect of Solution pH

1993 ◽  
Vol 333 ◽  
Author(s):  
Shi-Ben Xing ◽  
Isabelle S. Muller ◽  
Ian L. Pegg
Keyword(s):  
Nuclear Waste ◽  
Glass Composition ◽  
Ph Dependence ◽  
Solution Ph ◽  
Ph Values ◽  
Waste Vitrification ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Soluble Components ◽  
Glass Compositions

ABSTRACTIn our previous studies on the optimization of glass compositions for high-level nuclear waste vitrification it was found that, over certain composition ranges, PCT leachate concentrations increased dramatically with very small changes in glass composition. The large differences that are observed between the leachate pH values for the “durable” and the “less-durable” glasses is one possible cause for this strongly non-linear glass composition effect; conversely, the pH difference may be merely another symptom. In this study, four simulated nuclear waste glasses (two of the less-durable and two of the durable types), were leached in both zwitterionic and inorganic buffer solutions, at fixed pH-values in the ranges of 7 to 12. The very different leaching behaviors of the two types of glasses persisted and, furthermore, different pH-dependence was found despite their very similar glass composition. This study suggests that the leachate pH difference observed between the less-durable and the durable glasses under uncontrolled pH conditions is not the major cause of the large difference of leaching behavior between those glasses. The normalized release ratios of soluble components (B, Li, Na) to Si show significant differences for the two types of glasses.

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