Modelling the Kinetics of Hydrogen Evolution on Metals for Nuclear Applications

Author(s):  
Kenneth R. Trethewey

It is well known that some metals suffer damage caused by the evolution of hydrogen in certain conditions in nuclear applications. Of particular current interest is the use of alloys for use in containers for the long-term storage of high level nuclear waste. Calculations for the rates of corrosion of metals where hydrogen evolution is possible rely upon measurements of the reaction kinetics, but it is difficult to obtain reliable and accurate values for the kinetic constants. Standard electrochemical tests can be used, but the analysis of the results is complex because of the need to deconvolute the curves. This paper presents a computer model for the analysis of the data that is checked by its use on experimental data from a number of nuclear materials.

1990 ◽  
Vol 212 ◽  
Author(s):  
D. E. Grandstaff ◽  
V. J. Grassi ◽  
A. C. Lee ◽  
G. C. Ulmer

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.


2006 ◽  
Vol 932 ◽  
Author(s):  
Damien Féron ◽  
Digby D. Macdonald

ABSTRACTThe corrosion resistance of container materials in underground repositories is an important issue for the safe disposal of High Level Nuclear Waste (HLNW). The reliable prediction of container degradation rate and engineering barrier integrity over extended periods, up to several thousands years or even several hundreds of thousands of years, represents one of the greatest scientific and technical challenges. The first and the second International Workshops on Prediction of Long Term Corrosion Behaviour in Nuclear Waste Systems, which were held in 2001 (Cadarache) and 2004 (Nice), sought to compare the scientific and experimental approaches that are being developed in various organisations worldwide for predicting long term corrosion phenomena, including corrosion strategies for interim storage and geological disposal. The lessons learned during these Workshops, include the necessity of developing two approaches based on semi-empiricism and determinism in a complementary manner for effective prediction. The use of archaeological artefacts to demonstrate the feasibility of long term storage and to provide a database for testing and validating modelling work was also emphasized.


1990 ◽  
Vol 212 ◽  
Author(s):  
Charles G. Interrante ◽  
Carla A. Messina ◽  
Anna C. Fraker

ABSTRACTThe work reported here is part of a program conducted by the Nuclear Regulatory Commission on the efficacy of proposed plans for radionuclide containment for long-term storage of high-level nuclear waste (HLW). An important element of that program is the review and evaluation of available literature on components of a waste package. A review process and a database have been developed and tailored to provide information quickly to an individual who has a question about a particular material or component of a waste package. The database is uniquely suited to serve as a guide to indicate special areas where data and information needs exist on questions related to radionuclide containment. Additions to the database are made as information becomes available, and this source is as current as the published literature. A description of the review process and the database is given.


Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 326 ◽  
Author(s):  
Olga Senko ◽  
Marina Gladchenko ◽  
Olga Maslova ◽  
Elena Efremenko

The aim of this paper is to demonstrate the possibilities of anaerobic sludge cells immobilized into poly(vinyl alcohol) cryogel for the methanogenic conversion of various lignocellulosic waste and other media containing antibiotics (ampicillin, kanamycin, benzylpenicillin) or pesticides (chlorpyrifos or methiocarb and its derivatives). It was established that the immobilized cells of the anaerobic consortium can be stored frozen for at least three years while preserving a high level of metabolic activity. The cells after the long-term storage in an immobilized and frozen state were applied for the methanogenesis of a wide number of wastes, and an increase in both methane yield and methane portion in the produced biogas as compared to the conventionally used suspended anaerobic sludge cells, was ensured. It was shown that the “additional” introduction of bacterial Clostridium acetobutylicum, Pseudomonas sp., Enterococcus faecalis cells (also immobilized using same support) improves characteristics of methanogenesis catalyzed by immobilized anaerobic sludge.


2014 ◽  
Vol 670-671 ◽  
pp. 376-381 ◽  
Author(s):  
Aleksey Adamtsevich ◽  
Aleksey Eremin ◽  
Andrey Pustovgar ◽  
Stanislav Pashkevich ◽  
Sergey Nefedov

This article is a stage of the author’s research into the impact of different factors on the hydration of mineral binders. The problem of cement activity decrease due to adsorption moisture influence during long-term storage in normal conditions (20°C and 50% RH) was examined. The influence of storage period in airtight and non-airtight conditions on the kinetics of heat evolution during hydration as well as on phase composition of Portland cement was characterized using experimental methods.


1997 ◽  
Vol 120 (1) ◽  
pp. 19-40 ◽  
Author(s):  
Carl A. Beard ◽  
John J. Buksa ◽  
J. Wiley Davidson ◽  
Stacey L. Eaton ◽  
John J. Park ◽  
...  

2010 ◽  
Vol 1265 ◽  
Author(s):  
Odile Majerus ◽  
Daniel Caurant ◽  
Ning Li ◽  
Jean-Baptiste Baudouin ◽  
Gabriela Manolescu ◽  
...  

AbstractThe high level nuclear waste load is likely to increase in the future containment glasses, rising new questions about their long-term chemical durability. In this study sodium borosilicate compositions with Si substituted for RE (RE = rare earth) are altered under static conditions at fixed pH (8.5). The Na and B leached fractions reached just after the rate drop increase with the RE2O3 content. Part of the RE ions remain in the altered layer which is significantly de-polymerised (IR-ATR and NMR results). Their environment is reorganized and adopts a more centrosymetrical character. The higher leached fractions are attributed to rapid hydrolysis of Si/B-O-RE bonds with respect to Si-O-Si bonds.


PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262275
Author(s):  
Stephan Hilpmann ◽  
Miriam Bader ◽  
Robin Steudtner ◽  
Katharina Müller ◽  
Thorsten Stumpf ◽  
...  

The safe disposal of high-level radioactive waste in a deep geological repository is a huge social and technical challenge. So far, one of the less considered factors needed for a long-term risk assessment, is the impact of microorganisms occurring in the different host rocks. Even under the harsh conditions of salt formations different bacterial and archaeal species were found, e. g. Halobacterium sp. GP5 1–1, which has been isolated from a German rock salt sample. The interactions of this archaeon with uranium(VI), one of the radionuclides of major concern for the long-term storage of high-level radioactive waste, were investigated. Different spectroscopic techniques, as well as microscopy, were used to examine the occurring mechanisms on a molecular level leading to a more profound process understanding. Batch experiments with different uranium(VI) concentrations showed that the interaction is not only a simple, but a more complex combination of different processes. With the help of in situ attenuated total reflection Fourier-transform infrared spectroscopy the association of uranium(VI) onto carboxylate groups was verified. In addition, time-resolved laser-induced luminescence spectroscopy revealed the formation of phosphate and carboxylate species within the cell pellets as a function of the uranium(VI) concentration and incubation time. The association behavior differs from another very closely related halophilic archaeon, especially with regard to uranium(VI) concentrations. This clearly demonstrates the importance of studying the interactions of different, at first sight very similar, microorganisms with uranium(VI). This work provides new insights into the microbe-uranium(VI) interactions at highly saline conditions relevant to the long-term storage of radioactive waste in rock salt.


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