The Use of Natural Analogues in the Long-Term Extrapolation of Glass Corrosion Processes

1987 ◽  
pp. 142-152 ◽  
Author(s):  
W. Lutze ◽  
B. Grambow ◽  
R. C. Ewing ◽  
M. J. Jercinovic
Keyword(s):  
Glass Corrosion ◽  
Natural Analogues

scholarly journals Comparison of the Corrosion Behavior of Tank 51 Sludge-Based Glass and a Nonradioactive Homologue Glass

1996 ◽  
Vol 465 ◽  
Author(s):  
L. Nuñez ◽  
W. L. Ebert ◽  
S. F. Wolf ◽  
J. K. Bates
Keyword(s):  
Corrosion Behavior ◽  
Lower Solution ◽  
Solution Ph ◽  
Consistency Test ◽  
Glass Corrosion ◽  
Dissolution Tests ◽  
One Year ◽  
The Relationship ◽  
Solution Volume

ABSTRACTWe are characterizing the corrosion behavior of the radioactive glass that was made with sludge from Tank 51 at the Defense Waste Processing Facility (DWPF) and a nonradioactive glass having the same composition, except for the absence of radionuclides. Static dissolution tests are being conducted in a tuff groundwater solution at glass surface area/solution volume ratios (S/V) of 2000 and 20,000 m−1. These tests are being conducted to assess the relationship between the behavior of this glass in a 7-day Product Consistency Test and in long-term tests, to assess the effects of radionuclides on the glass corrosion behavior, and to measure the disposition of radionuclides that are released as the radioactive glass corrodes. The radioactive glass reacts slower than the nonradioactive glass through the longest test durations completed to date, which are 140 days for tests at 2000 m−1 and about 400 days for tests at 20,000 m−1. This is probably because radiolysis results in lower solution pH values being maintained in tests with the radioactive glass. Rate-affecting alteration phases that had formed within one year in tests with other glasses having compositions similar to the Tank 51 glass have not yet formed in tests with either glass.

Natural Analogues: Alamosa River Monzonite Intrusive into Tuffaceous and Andesitic Rocks

1982 ◽  
Vol 15 ◽  
Author(s):  
D. G. Brookins ◽  
M. S. Abashian ◽  
L. H. Cohen ◽  
A. E. Williams ◽  
H. A. Wollenberg ◽  
...  
Keyword(s):  
Fission Product ◽  
Conceptual Models ◽  
Laboratory Data ◽  
Hydrothermal Systems ◽  
Rock Matrix ◽  
Natural Processes ◽  
Natural Analogues ◽  
Time Periods ◽  
Over Time

This project encompasses investigations of selected natural analogues of minerals and rocks containing radioelements and fission-product elements, to ascertain how radionuclides and their daughter elements may migrate from sites of origin in response to long-term natural processes such as heating due to an igneous intrusion, circulating hydrothermal systems, diffusion through the rock matrix, weathering and erosion. Comparison of natural occurrences with conceptual models based on laboratory data will furnish a test of such models over time periods comparable to or longer than those expected for a repository.

Phase Relations of the Uranyl Oxide Hydrates and their Relevance to the Disposal of Spent Fuel

1990 ◽  
Vol 212 ◽  
Author(s):  
R. J. Finch ◽  
R. C. Ewing
Keyword(s):  
General Formula ◽  
Phase Relations ◽  
Molecular Water ◽  
Spent Fuel ◽  
Geologic Repository ◽  
Structural Sheet ◽  
Natural Analogues ◽  
Ph Conditions ◽  
Image Position

ABSTRACTUranyl oxide hydrates, formed by the alteration of uraninite, are natural analogues for the long-term corrosion products of spent fuel in a geologic repository under oxidizing conditions. The uranyl oxide hydrates may be represented by the general formula:Pb-bearing hydrates require the addition of a neutral uranyl group into the structural sheet (UO2(OH)2) for each interlayer Pb ion. Distortion of the structure associated with the additional uranyl groups is reduced by replacing two structural hydroxyls with a structural oxygen and a molecular water. The general formula for the Pb-uranyl oxide hydrates is:This hypothesis explains the paragenetic sequences:1) schoepite ➛ billietite ➛ protasite ➛ bauranoite2) schoepite ➛ vandendriesscheite ➛ fourmarierite ➛ masuyite ➛ wölsendorfite3) schoepite ➛ vandendriesscheite ➛ fourmarierite ➛ ± masuyite ➛ sayrite ➛ curite, and indicates that, under relatively high pH conditions, schoepite will not be the long-term solubility-controlling phase for uranium in uranium-rich groundwaters.

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.

scholarly journals Laboratory Testing of Waste Glass Aqueous Corrosion; Effects of Experimental Parameters

1993 ◽  
Vol 333 ◽  
Author(s):  
W.L. Ebert ◽  
J.J. Mazer
Keyword(s):  
Ion Exchange ◽  
Corrosion Rate ◽  
Laboratory Tests ◽  
Water Diffusion ◽  
Waste Glass ◽  
Solution Chemistry ◽  
Exchange Reactions ◽  
Glass Corrosion ◽  
Hydrolysis Reactions

ABSTRACTA literature survey has been performed to assess the effects of the temperature, glass surface area/leachate volume ratio, leachant composition, leachant flow rate, and glass composition (actual radioactive vs. simulated glass) used in laboratory tests on the measured glass reaction rate. The effects of these parameters must be accounted for in mechanistic models used to project glass durability over long times. Test parameters can also be used to highlight particular processes in laboratory tests. Waste glass corrosion results as water diffusion, ion exchange, and hydrolysis reactions occur simultaneously to devitrify the glass and release soluble glass components into solution. The rates of these processes are interrelated by the effects of the solution chemistry and glass alteration phases on each process, and the dominant (fastest) process may change as the reaction progresses. Transport of components from the release sites into solution may also affect the observed corrosion rate. The reaction temperature will affect the rate of each process, while other parameters will affect the solution chemistry and the particular processes that are observed during the test. The early stages of corrosion will be observed under test conditions which maintain dilute leachates and the later stages will be observed under conditions that generate more concentrated leachate solutions. Typically, water diffusion and ion exchange reactions dominate the observed glass corrosion in dilute solutions, while hydrolysis reactions are dominant in more concentrated solutions. Which process controls the long-term glass corrosion is not fully understood, and the long-term corrosion rate may be either transport- or reaction-limited.

scholarly journals Applying laboratory methods for durability assessment of vitrified material to archaeological samples

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Lorena Nava-Farias ◽  
James J. Neeway ◽  
Michael J. Schweiger ◽  
José Marcial ◽  
Nathan L. Canfield ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Iron Age ◽  
Test Methods ◽  
Durability Test ◽  
Laboratory Methods ◽  
Near Surface ◽  
Glass Corrosion ◽  
Durability Assessment ◽  
Nuclear Waste Forms

AbstractLaboratory testing used to assess the long-term chemical durability of nuclear waste forms may not be applicable to disposal because the accelerated conditions may not represent disposal conditions. To address this, we examine the corrosion of vitrified archeological materials excavated from the near surface of a ~1500-year old Iron Age Swedish hillfort, Broborg, as an analog for the disposal of vitrified nuclear waste. We compare characterized site samples with corrosion characteristics generated by standard laboratory durability test methods including the product consistency test (PCT), the vapor hydration test (VHT), and the EPA Method 1313 test. Results show that the surficial layer of the Broborg samples resulting from VHT displays some similarities to the morphology of the surficial layer formed over longer timescales in the environment. This work provides improved understanding of long-term glass corrosion behavior in terms of the thickness, morphology, and chemistry of the surficial features that are formed.

Formation of secondary phases after long-term corrosion of simulated HLW glass in brine solutions at 190 °C

2002 ◽  
Vol 90 (9-11) ◽  
Author(s):  
P. Zimmer ◽  
E. Bohnert ◽  
Dirk Bosbach ◽  
Jae-Il Kim ◽  
E. Althaus
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Glass Powder ◽  
High Level Waste ◽  
Secondary Phases ◽  
Batch Experiments ◽  
Salt Solutions ◽  
Glass Corrosion ◽  
High Level

SummaryThe behavior of rare earth elements (REE) as chemical analogues for actinides during glass corrosion was studied with static long-term batch experiments (7.5 years) at 190 °C. Corrosion tests were carried out using a simulated inactive high level waste (HLW) glass powder. Two different highly concentrated salt solutions (NaCl-rich and MgCl

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