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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Accommodation of helium in PuO
AU - Neilson, William D
AU - Steele, Helen
AU - Kaltsoyannis, Nikolas
AU - Murphy, Samuel T
PY - 2022/4/14
Y1 - 2022/4/14
N2 - The high alpha-activity of plutonium dioxide (PuO ) results in significant ingrowth of radiogenic helium (He) in the aged material. To safely store/dispose PuO or use in applications such as space exploration, the impact of He accumulation needs to be understood. In this work, defect energies obtained using a density functional theory (DFT) + + D3 scheme are used in a point defect model constructed for PuO to predict the method of He incorporation within the PuO lattice. The simulations predict that the preferred incorporation site for He in PuO is a plutonium vacancy, however, the point defect model indicates that helium will be accommodated as an interstitial irrespective of He concentration and across a wide stoichiometric range. By considering the charge imbalance that arises due to incorporation of Am ions it is shown that He accommodation in oxygen vacancy sites will dominate in PuO as the material ages.
AB - The high alpha-activity of plutonium dioxide (PuO ) results in significant ingrowth of radiogenic helium (He) in the aged material. To safely store/dispose PuO or use in applications such as space exploration, the impact of He accumulation needs to be understood. In this work, defect energies obtained using a density functional theory (DFT) + + D3 scheme are used in a point defect model constructed for PuO to predict the method of He incorporation within the PuO lattice. The simulations predict that the preferred incorporation site for He in PuO is a plutonium vacancy, however, the point defect model indicates that helium will be accommodated as an interstitial irrespective of He concentration and across a wide stoichiometric range. By considering the charge imbalance that arises due to incorporation of Am ions it is shown that He accommodation in oxygen vacancy sites will dominate in PuO as the material ages.
U2 - 10.1039/d1cp05570d
DO - 10.1039/d1cp05570d
M3 - Journal article
C2 - 35319031
VL - 24
SP - 2845
EP - 8250
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
SN - 1463-9076
ER -