The Influence of Gamma Irradiation on the Leaching Behavior of a Modified Synroc-B Ceramic Waste Form

1981 ◽  
Vol 6 ◽  
Author(s):  
A. G. Solomah
Keyword(s):  
Waste Form ◽  
Leaching Behavior ◽  
Acid Base ◽  
Γ Irradiation ◽  
Ph Measurements ◽  
Ceramic Waste ◽  
Acid Generation ◽  
Leaching Experiments ◽  
High Level ◽  
Base Formation

ABSTRACTThe leaching behavior of a sintered Modified SYNROC-B ceramic waste form containing l0wt% simulated high level radioactive waste, under the influence of γ-irradiation, has been investigated. Similar leaching experiments have been carried out in the absence of γ-irradiation, and the leach rates of Ba and Cs are presented for comparison studies. Acid/Base formation has been monitored through pH measurements of the leachants. A decrease in pH is found with γ-irradiation due to radiolytic nitric acid generation. Higher initial leach rates with a more pronounced subsequent drop in the case of Ba and Cs were observed with γ-irradiation than without irradiation. The results of the study are presented and discussed.

scholarly journals Characterization of Composite Ceramic High Level Waste Forms

1997 ◽  
Vol 481 ◽  
Author(s):  
S. M. Frank ◽  
K. J. Bateman ◽  
T. DiSanto ◽  
S. G. Johnson ◽  
T. L. Moschetti ◽  
...  
Keyword(s):  
Spent Nuclear Fuel ◽  
Argonne National Laboratory ◽  
Fission Products ◽  
Composite Ceramic ◽  
Waste Form ◽  
High Level Waste ◽  
Ceramic Waste ◽  
Chloride Form ◽  
Physical Measurements ◽  
High Level

ABSTRACTArgonne National Laboratory has developed a composite ceramic waste form for the disposition of high level radioactive waste produced during electrometallurgical conditioning of spent nuclear fuel. The electrorefiner LiCl/KCl eutectic salt, containing fission products and transuranics in the chloride form, is contacted with a zeolite material which removes the fission products from the salt. After salt contact, the zeolite is mixed with a glass binder. The zeolite/glass mixture is then hot isostatic pressed (HIPed) to produce the composite ceramic waste form. The ceramic waste form provides a durable medium that is well suited to incorporate fission products and transuranics in the chloride form. Presented are preliminary results of the process qualification and characterization studies, which include chemical and physical measurements and product durability testing, of the ceramic waste form.

scholarly journals Development of a ceramic waste form for high-level waste disposal

1999 ◽  
Vol 556 ◽  
Author(s):  
D. W. Esh ◽  
K. M. Goff ◽  
K. T. Hirsche ◽  
T. J. Battisti ◽  
M. F. Simpson ◽  
...  
Keyword(s):  
Spent Nuclear Fuel ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Fission Products ◽  
Waste Form ◽  
High Level Waste ◽  
Durability Test ◽  
Ceramic Waste ◽  
High Level ◽  
The Impact

AbstractA ceramic waste form is being developed by Argonne National Laboratory* (ANL) as part of the demonstration of the electrometallurgical treatment of spent nuclear fuel [1]. The halide, alkaline earth, alkali, transuranic, and rare earth fission products are stabilized in zeolite which is combined with glass and processed in a hot isostatic press (HIP) to form a ceramic composite. The mineral sodalite is formed in the HIP from the zeolite precursor. The process, from starting materials to final product, is relatively simple. An overview of the processing operations is given. The metrics that have been developed to measure the success or completion of processing operations are developed and discussed. The impact of variability in processing metrics on the durability of the final product is presented. The process is demonstrated to be robust for the type and range of operation metrics considered and the performance metric (PCT durability test) against which the operation metrics are evaluated.

Long-Term Radioactivity Release From Solidified High-Level Waste -Part I: An Approach To Evaluating Experimental Data

1981 ◽  
Vol 11 ◽  
Author(s):  
Friedrich K. Altenhein ◽  
Werner Lutze ◽  
Rodney C. Ewing
Keyword(s):  
Source Term ◽  
Elevated Temperatures ◽  
Relative Sensitivity ◽  
Reaction Rates ◽  
Waste Form ◽  
High Level Waste ◽  
Leach Rate ◽  
Leaching Experiments ◽  
High Level

Safety and risk analyses for the isolation of radioactive waste in a repository must begin with a source term to quantify the amount of radioactivity released from the waste form under a specific set of conditions. The interaction of the waste form with aqueous solutions is the most important mechanism to consider, as any material released may be dissolved and reach the biosphere. In this regard the behaviour of heat generating high-level waste is of particular importance, because reaction rates are higher at elevated temperatures. A long-term leach rate was derived from previous and continuing experimental work. The purpose of this paper is not to describe the “real case” release but rather to provide guidelines for the design of leaching experiments and determine the required precision for the data. This can be derived from the relative sensitivity of extrapolated leach rates for various parameters measured in laboratory experiments.

Study of Natural Minerals of U-Ryrochlore-Type Structure as Analogues of Plutonium Ceramic Waste-form

2002 ◽  
Vol 713 ◽  
Author(s):  
Roman V. Bogdanov ◽  
Yuri F. Batrakov ◽  
Elena V. Puchkova ◽  
Andrey S. Sergeev ◽  
Boris E. Burakov
Keyword(s):  
Chemical Shifts ◽  
Pyrochlore Structure ◽  
Type Structure ◽  
Waste Form ◽  
X Ray ◽  
Ceramic Waste ◽  
Natural Minerals ◽  
The Us ◽  
Pyrochlore Type

ABSTRACTAt present, crystalline ceramic based on titanate pyrochlore, (Ca,Gd,Hf,Pu,U)2Ti2O7, is considered as the US candidate waste form for the immobilization of weapons grade plutonium. Naturally occuring U-bearing minerals with pyrochlore-type structure: hatchettolite, betafite, and ellsworthite, were studied in orders to understand long-term radiation damage effects in Pu ceramic waste forms. Chemical shifts (δ) of U(Lδ1)– and U(Lβ1) – X-ray emission lines were measured by X-ray spectrometry. Calculations were performed on the basis of a two-dimensional δLá1- and δLδ1- correlation diagram. It was shown that 100% of uranium in hatchettolite and, probably, 95-100% of uranium in betafite are in the form of (UO2)2+. formal calculation shows that in ellsworthite only 20% of uranium is in the form of U4+ and 80% of the rest is in the forms of U5+ and U6+. The conversion of the initial U4+ ion originally occurring in the pyrochlore structure of natural minerals to (UO2)2+ due to metamict decay causes a significant increase in uranium mobility.

First-principles investigation of the Lewis acid–base adduct formation at the methylammonium lead iodide surface

2018 ◽  
Vol 20 (16) ◽  
pp. 11183-11195 ◽  
Author(s):  
Giacomo Giorgi ◽  
Koichi Yamashita ◽  
Hiroshi Segawa
Keyword(s):  
Lewis Acid ◽  
First Principles ◽  
Adduct Formation ◽  
Lead Iodide ◽  
Acid Base ◽  
Methylammonium Lead Iodide ◽  
Base Formation

Theoretical insights into the mechanism of Lewis acid–base formation at the surface of methylammonium lead iodide (MAPbI3).

Study of simulated HLW-glass leaching behavior under low oxygen repository condition

2006 ◽  
Vol 932 ◽  
Author(s):  
Zhang Hua ◽  
Luo Shanggeng
Keyword(s):  
Glass Surface ◽  
Diffraction Peak ◽  
Ambient Atmosphere ◽  
Low Oxygen ◽  
Secondary Products ◽  
Leaching Behavior ◽  
Geologic Disposal ◽  
Oxygen Condition ◽  
High Level ◽  
Glass Leaching

ABSTRACTMany countries have recognized vitrification as the suitable solidification method for conditioning high level radioactive waste before they are isolated from biosphere in geologic disposal. This paper studies the leaching behavior of a simulated HLW-glass (90Nd/10) under low oxygen repository condition during 1.5 years. The leaching results showed that the glass was corroded less under low oxygen condition than under ambient atmosphere. XRD analyses showed some little diffraction peak appeared on the leached glass surface at 150°C. At the same time, no diffraction peak appeared on the leached glass surface at 90°C. The secondary products formed on the surface of the leached glass contained mainly Si, Al, Ca and Fe.

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