UO2 samples doped with the strong α-emitter 238Pu were periodically characterised to study the potential effects of α-self-irradiation on spent nuclear fuel during storage. The degradation of the thermal properties and microstructure of the samples were monitored using the Laser Flash technique (LAF), X-Ray Diffraction (XRD), and Scanning and Transmission Electron Microscopy (SEM, TEM). The thermal conductivity decreased with a non-linear behaviour as a function of the α-dose. Three clearly different stages in the thermal conductivity degradation could be detected, and saturation was reached at relatively low doses (0.035 dpa). In combination with analyses of the microstrain measured by XRD, and TEM images, these three phases could be attributed to three stages of radiation-induced defect generation and clustering. SEM inspection showed the thermal conductivity degradation cannot be due to loss of integrity or grain boundary opening. The radiation damage produced resulted in the formation of dislocation loops as observed by TEM.
Radiation effects in alpha-doped UO2 / De Bona, E.; Benedetti, A.; Dieste, O.; Staicu, D.; Wiss, T.; Konings, R. J. M.. - In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION B, BEAM INTERACTIONS WITH MATERIALS AND ATOMS. - ISSN 0168-583X. - 468:(2020), pp. 54-59. [10.1016/j.nimb.2020.01.024]
Radiation effects in alpha-doped UO2
De Bona, E.Primo
;Benedetti, A.Secondo
;
2020-01-01
Abstract
UO2 samples doped with the strong α-emitter 238Pu were periodically characterised to study the potential effects of α-self-irradiation on spent nuclear fuel during storage. The degradation of the thermal properties and microstructure of the samples were monitored using the Laser Flash technique (LAF), X-Ray Diffraction (XRD), and Scanning and Transmission Electron Microscopy (SEM, TEM). The thermal conductivity decreased with a non-linear behaviour as a function of the α-dose. Three clearly different stages in the thermal conductivity degradation could be detected, and saturation was reached at relatively low doses (0.035 dpa). In combination with analyses of the microstrain measured by XRD, and TEM images, these three phases could be attributed to three stages of radiation-induced defect generation and clustering. SEM inspection showed the thermal conductivity degradation cannot be due to loss of integrity or grain boundary opening. The radiation damage produced resulted in the formation of dislocation loops as observed by TEM.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione
