Annealing tests of in-pile irradiated oxide coated U–Mo/Al–Si dispersed nuclear fuel

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. a b s t r a c t U-Mo/Al based nuclear fuels have been worldwide considered as a promising high density fuel for the conversion of high flux research reactors from highly enriched uranium to lower enrichment. In this paper, we present the annealing test up to 1800 °C of in-pile irradiated U-Mo/Al-Si fuel plate samples. More than 70% of the fission gases (FGs) are released during two major FG release peaks around 500 °C and 670 °C. Additional characterisations of the samples by XRD, EPMA and SEM suggest that up to 500 °C FGs are released from IDL/matrix interfaces. The second peak at 670 °C representing the main release of FGs originates from the interaction between U-Mo and matrix in the vicinity of the cladding.

Kr implantation into heavy ion irradiated monolithic U–Mo/Al systems: SIMS and SEM investigations

“…Comparing the present results to those after thermal annealing on in-pile irradiated IRIS4 fuel [29], the following becomes evident:…”

“…In the following, the obtained results are compared to two exemplary in-pile irradiation tests, the RERTR6 test performed with monolithic layer systems [27] and the IRIS4 test realized with oxide-coated atomized UeMo powder dispersed in an Al(2.1wt%Si) matrix [28,29]. Additionally, the irradiation parameters for all these presented tests are listed in Table 3.…”

“…(B-) SEM SE image of irradiated IRIS4 fuel annealed at 500 C[29].In both tests, mm-sized porosities are found in the IDL (see red circles). Moreover, several porosities are interconnected to each other (B-).…”

Measurement of fission gas release from irradiated U–Mo monolithic fuel samples

“…Heat of reaction measurements performed on unirradiated U-10Mo fuels dispersed in an Al matrix by Ryu et al also showed an exothermic reaction occurring around 645°C that was associated with melting of the Al matrix [20]. Similarly, annealing tests performed by Zweifel et al on irradiated U-Mo fuel dispersed in an Al-Si matrix showed a high fission gas release at 670°C [21]. While neither aforementioned study contained Zr, the exothermic reaction is primarily driven by melting of the Al alloy cladding and/or matrix (in the case of dispersion fuels).…”

“…The difference with the current system is that the Zr serves as a diffusion barrier between the Al cladding and U-Mo fuel, to prevent interaction layer formation as described in Refs. [20,21]. However, an exothermic reaction is observed following the melting of the cladding despite the presence of this diffusion barrier.…”