TY - JOUR
T1 - Thermal expansion of the nuclear fuel-sodium reaction product Na3(U0.84(2),Na0.16(2))O4 - Structural mechanism and comparison with related sodium-metal ternary oxides
AU - Illy, Marie Claire
AU - Smith, Anna L.
AU - Wallez, Gilles
AU - Raison, Philippe E.
AU - Caciuffo, Roberto
AU - Konings, Rudy J.M.
PY - 2017/7/1
Y1 - 2017/7/1
N2 - Na3.16(2)UV,VI 0.84(2)O4 is obtained from the reaction of sodium with uranium dioxide under oxygen potential conditions typical of a sodium-cooled fast nuclear reactor. In the event of a breach of the steel cladding, it would be the dominant reaction product forming at the rim of the mixed (U,Pu)O2 fuel pellets. High-temperature X-ray diffraction measurements show that a distortion of the uranium environment in Na3.16(2)UV,VI 0.84(2)O4 results in a strongly anisotropic thermal expansion. A comparison with several related sodium metallates Nan-2Mn+On-1 - including Na3SbO4 and Na3TaO4, whose crystal structures are reported for the first time - has allowed us to assess the role played in the lattice expansion by the Mn+ cation radius and the Na/M ratio. On this basis, the thermomechanical behavior of the title compound is discussed, along with those of several related double oxides of sodium and actinide elements, surrogate elements, or fission products.
AB - Na3.16(2)UV,VI 0.84(2)O4 is obtained from the reaction of sodium with uranium dioxide under oxygen potential conditions typical of a sodium-cooled fast nuclear reactor. In the event of a breach of the steel cladding, it would be the dominant reaction product forming at the rim of the mixed (U,Pu)O2 fuel pellets. High-temperature X-ray diffraction measurements show that a distortion of the uranium environment in Na3.16(2)UV,VI 0.84(2)O4 results in a strongly anisotropic thermal expansion. A comparison with several related sodium metallates Nan-2Mn+On-1 - including Na3SbO4 and Na3TaO4, whose crystal structures are reported for the first time - has allowed us to assess the role played in the lattice expansion by the Mn+ cation radius and the Na/M ratio. On this basis, the thermomechanical behavior of the title compound is discussed, along with those of several related double oxides of sodium and actinide elements, surrogate elements, or fission products.
KW - Crystal structures
KW - Sodium-cooled fast reactors
KW - Thermal expansion
UR - http://www.scopus.com/inward/record.url?scp=85018510214&partnerID=8YFLogxK
U2 - 10.1016/j.jnucmat.2017.03.045
DO - 10.1016/j.jnucmat.2017.03.045
M3 - Article
AN - SCOPUS:85018510214
SN - 0022-3115
VL - 490
SP - 101
EP - 107
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
ER -