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Thermal oxidation of nuclear graphite: A large scale waste treatment option

This study has investigated the laboratory scale thermal oxidation of nuclear graphite, as a proof-of-concept for the treatment and decommissioning of reactor cores on a larger industrial scale. If showed to be effective, this technology could have promising international significance with a conside...

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Detalles Bibliográficos
Autores principales: Theodosiou, Alex, Jones, Abbie N., Marsden, Barry J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5549958/
https://www.ncbi.nlm.nih.gov/pubmed/28793326
http://dx.doi.org/10.1371/journal.pone.0182860
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author Theodosiou, Alex
Jones, Abbie N.
Marsden, Barry J.
author_facet Theodosiou, Alex
Jones, Abbie N.
Marsden, Barry J.
author_sort Theodosiou, Alex
collection PubMed
description This study has investigated the laboratory scale thermal oxidation of nuclear graphite, as a proof-of-concept for the treatment and decommissioning of reactor cores on a larger industrial scale. If showed to be effective, this technology could have promising international significance with a considerable impact on the nuclear waste management problem currently facing many countries worldwide. The use of thermal treatment of such graphite waste is seen as advantageous since it will decouple the need for an operational Geological Disposal Facility (GDF). Particulate samples of Magnox Reactor Pile Grade-A (PGA) graphite, were oxidised in both air and 60% O(2), over the temperature range 400–1200°C. Oxidation rates were found to increase with temperature, with a particular rise between 700–800°C, suggesting a change in oxidation mechanism. A second increase in oxidation rate was observed between 1000–1200°C and was found to correspond to a large increase in the CO/CO(2) ratio, as confirmed through gas analysis. Increasing the oxidant flow rate gave a linear increase in oxidation rate, up to a certain point, and maximum rates of 23.3 and 69.6 mg / min for air and 60% O(2) respectively were achieved at a flow of 250 ml / min and temperature of 1000°C. These promising results show that large-scale thermal treatment could be a potential option for the decommissioning of graphite cores, although the design of the plant would need careful consideration in order to achieve optimum efficiency and throughput.
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spelling pubmed-55499582017-08-15 Thermal oxidation of nuclear graphite: A large scale waste treatment option Theodosiou, Alex Jones, Abbie N. Marsden, Barry J. PLoS One Research Article This study has investigated the laboratory scale thermal oxidation of nuclear graphite, as a proof-of-concept for the treatment and decommissioning of reactor cores on a larger industrial scale. If showed to be effective, this technology could have promising international significance with a considerable impact on the nuclear waste management problem currently facing many countries worldwide. The use of thermal treatment of such graphite waste is seen as advantageous since it will decouple the need for an operational Geological Disposal Facility (GDF). Particulate samples of Magnox Reactor Pile Grade-A (PGA) graphite, were oxidised in both air and 60% O(2), over the temperature range 400–1200°C. Oxidation rates were found to increase with temperature, with a particular rise between 700–800°C, suggesting a change in oxidation mechanism. A second increase in oxidation rate was observed between 1000–1200°C and was found to correspond to a large increase in the CO/CO(2) ratio, as confirmed through gas analysis. Increasing the oxidant flow rate gave a linear increase in oxidation rate, up to a certain point, and maximum rates of 23.3 and 69.6 mg / min for air and 60% O(2) respectively were achieved at a flow of 250 ml / min and temperature of 1000°C. These promising results show that large-scale thermal treatment could be a potential option for the decommissioning of graphite cores, although the design of the plant would need careful consideration in order to achieve optimum efficiency and throughput. Public Library of Science 2017-08-09 /pmc/articles/PMC5549958/ /pubmed/28793326 http://dx.doi.org/10.1371/journal.pone.0182860 Text en © 2017 Theodosiou et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Theodosiou, Alex
Jones, Abbie N.
Marsden, Barry J.
Thermal oxidation of nuclear graphite: A large scale waste treatment option
title Thermal oxidation of nuclear graphite: A large scale waste treatment option
title_full Thermal oxidation of nuclear graphite: A large scale waste treatment option
title_fullStr Thermal oxidation of nuclear graphite: A large scale waste treatment option
title_full_unstemmed Thermal oxidation of nuclear graphite: A large scale waste treatment option
title_short Thermal oxidation of nuclear graphite: A large scale waste treatment option
title_sort thermal oxidation of nuclear graphite: a large scale waste treatment option
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5549958/
https://www.ncbi.nlm.nih.gov/pubmed/28793326
http://dx.doi.org/10.1371/journal.pone.0182860
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