Research output: Contribution to conference - Without ISBN/ISSN › Conference paper › peer-review
Publication date | 1/01/2020 |
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Number of pages | 10 |
Pages | 983-992 |
<mark>Original language</mark> | English |
Event | 14th International Nuclear Fuel Cycle Conference, GLOBAL 2019 and Light Water Reactor Fuel Performance Conference, TOP FUEL 2019 - The Westin Seattle, Seattle, United States Duration: 22/09/2019 → 26/09/2019 http://globaltopfuel.ans.org/ |
Conference | 14th International Nuclear Fuel Cycle Conference, GLOBAL 2019 and Light Water Reactor Fuel Performance Conference, TOP FUEL 2019 |
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Country/Territory | United States |
City | Seattle |
Period | 22/09/19 → 26/09/19 |
Internet address |
Simple hydroxamic acids such as acetohydroxamic acid (AHA) have the ability to strip Pu(IV) and Np(IV) from tri-butyl phosphate into nitric acid by forming strong complexes with these ions. AHA has thus been identified as a suitable reagent for the control of Pu and Np in advanced separation processes for nuclear fuel reprocessing, such as the Advanced PUREX (Plutonium URanium EXtraction) and the Grouped ActiNide Extraction (GANEX) recycle processes. It is known that both free and complexed AHA undergo an acid catalysed hydrolysis reaction at low pH to form hydroxylamine (NH2OH) and acetic acid (CH3COOH), but the kinetics of this process is not fully understood in these systems. In this work, we have used Fe(III) as a non-active analogue for Pu(IV) and Np(IV) to investigate the hydrolysis kinetics of both free and complexed AHA by utilizing ion chromatography to measure the ingrowth of the acetate ion over time. In contrast to previous studies, our results show that the rate of AHA hydrolysis is inhibited in the presence of Fe(III). From our data we obtain an Arrhenius factor (A) of 1.25 x 10 11 dm 3.mol -1.s -1 and 3.71 x 10 18 dm 3.mol -1.s -1, and an activation energy (Ea) of 89.0 kJ.mol -1 and 137.4 kJ.mol -1 for the hydrolysis of the free and complexed AHA respectively.