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Synthesis and feasibility studies of doping U at Ti site of YTiO as a radioactive waste immobilization matrix
In pursuit of clean and green nuclear energy one of the major challenges is to effectively immobilize the nuclear waste. In this context A 2 B 2 O 7 type pyrochlore owing to its structural flexibility, ability to accommodate ions at both A/B-sites and high radiation tolerance has demonstrated excell...
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| Published in: | Dalton transactions : an international journal of inorganic chemistry 2023-10, Vol.52 (39), p.1417-14181 |
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| Main Authors: | , , , , , , |
| Format: | Article |
| Language: | |
| Online Access: | Get full text |
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| Summary: | In pursuit of clean and green nuclear energy one of the major challenges is to effectively immobilize the nuclear waste. In this context A
2
B
2
O
7
type pyrochlore owing to its structural flexibility, ability to accommodate ions at both A/B-sites and high radiation tolerance has demonstrated excellent capability to store highly radioactive actinide ions. To fill the major gap area of actinide doping at the B site we have taken up the challenge of doping uranium ions at the Ti site of Y
2
Ti
2
O
7
type pyrochlore. An yttria titanate (Y
2
Ti
2−
x
U
x
O
7
;
x
= 0.05, 0.075, 0.1, 0.2, and 0.3) based matrix with uranium doped at the Ti site was synthesized using a simple gel combustion route under an air atmosphere. Rietveld refined X-ray diffraction (XRD) demonstrated that Y
2
Ti
2
O
7
can accommodate U up to 5 mol% in the Ti site without any phase separation, which was further confirmed using Raman spectroscopy. Y
2
Ti
2
O
7
based matrices are found to be radiation stable up to 1000 kGy and at the same time they are moderately thermally stable and on a par with the values reported for pyrochlores. Uranium in Y
2
Ti
2
O
7
stabilizes in +6 oxidation state in the form of uranyl ion distributed near and far off from titanium vacancies with distinct excited state lifetime. This work could provide a smart and strategic way for selecting a suitable advanced ceramic matrix for immobilization of high level waste with additional and important information on solubility limit, actinide speciation, radiation/thermal stability, actinide concentration,
etc
.
The article summarieses the crystal chemistry of Y
2
Ti
2
O
7
for the Incorporation of U at Ti site as nuclear waste host matrix for nuclear industry. |
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| ISSN: | 1477-9226 1477-9234 |
| DOI: | 10.1039/d3dt02727a |