Abstract
| Translated title of the contribution | Controlled conversion of uranium carbide fission targets using water vapour |
|---|---|
| Original language | English |
| Title of host publication | 42èmes Journées des Actinides (42nd JdA) conference and 9th School on the Physics and Chemistry of the Actinides (9th SPCA), Bristol, UK |
| Editors | KR Hallam |
| Publication status | Published - 2012 |
Bibliographical note
Conference Organiser: Interface Analysis Centre, University of BristolHandle.net
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42èmes Journées des Actinides (42nd JdA) conference and 9th School on the Physics and Chemistry of the Actinides (9th SPCA), Bristol, UK. ed. / KR Hallam. 2012.
Research output: Chapter in Book/Report/Conference proceeding › Conference Contribution (Conference Proceeding)
TY - GEN
T1 - Controlled conversion of uranium carbide fission targets using water vapour
AU - Scott, TB
AU - Harker, Nicholas J
AU - Jones, CP
AU - Hallam, KR
AU - Heard, PJ
AU - Catherall, R
N1 - Conference Organiser: Interface Analysis Centre, University of Bristol
PY - 2012
Y1 - 2012
N2 - The safe disposal of radioactive waste arising from experimental fission studies at CERN is a key objective for the organisation. The current work has sought to determine a repeatable, reliable and safe method of converting UC2 fission targets into an acceptable uranium oxide waste form for subsequent disposal by the Swiss authorities. Research has drawn upon the experimental and analytical capabilities of the Interface Analysis Centre (IAC), a group specialising in nuclear materials research at the University of Bristol, England. Pills of UC2+C supplied by the ISOLDE group at CERN were oxidised in the presence of water vapour in a specialist gas exposure system at temperatures from 100 to 600°C. In all experiments the controlled oxidation of UC2 to a uranium oxide powder was observed, with x-ray diffraction analyses indicating an oxide composition between UO2 and U4O7 as the principal oxidation product. The evolving gas composition of the reaction cells indicated that two reactions occurred during water vapour exposure: (1) oxidation of UC2 to U-oxide and (2) oxidation of graphitic carbon to form CO2. The reaction rates of these two processes were observed to be significantly different, with carbide oxidation proceeding more rapidly than graphite oxidation. At elevated temperatures (≥300°C) the rate of carbide oxidation was controlled by the rate of water vapour diffusion, allowing for a controlled conversion of the target material. Stemming from the current work we will seek to upscale the experimental method and apparatus for waste conversion on a larger scale.
AB - The safe disposal of radioactive waste arising from experimental fission studies at CERN is a key objective for the organisation. The current work has sought to determine a repeatable, reliable and safe method of converting UC2 fission targets into an acceptable uranium oxide waste form for subsequent disposal by the Swiss authorities. Research has drawn upon the experimental and analytical capabilities of the Interface Analysis Centre (IAC), a group specialising in nuclear materials research at the University of Bristol, England. Pills of UC2+C supplied by the ISOLDE group at CERN were oxidised in the presence of water vapour in a specialist gas exposure system at temperatures from 100 to 600°C. In all experiments the controlled oxidation of UC2 to a uranium oxide powder was observed, with x-ray diffraction analyses indicating an oxide composition between UO2 and U4O7 as the principal oxidation product. The evolving gas composition of the reaction cells indicated that two reactions occurred during water vapour exposure: (1) oxidation of UC2 to U-oxide and (2) oxidation of graphitic carbon to form CO2. The reaction rates of these two processes were observed to be significantly different, with carbide oxidation proceeding more rapidly than graphite oxidation. At elevated temperatures (≥300°C) the rate of carbide oxidation was controlled by the rate of water vapour diffusion, allowing for a controlled conversion of the target material. Stemming from the current work we will seek to upscale the experimental method and apparatus for waste conversion on a larger scale.
M3 - Conference Contribution (Conference Proceeding)
BT - 42èmes Journées des Actinides (42nd JdA) conference and 9th School on the Physics and Chemistry of the Actinides (9th SPCA), Bristol, UK
A2 - Hallam, KR
ER -