A feasibility study of using CeO₂ as a surrogate material during the investigation of UO₂ thermal conductivity enhancement

ABSTRACT

A possible substitution of UO₂ for research purposes is the cerium dioxide (CeO₂) owing to its chemical and physical properties. Neutronic properties are different and fission is absent in the case of CeO₂; however, similarities were studied recently to have a possibility to compare the neutronic influence of secondary additives into the matrix. This paper deals with increasing the thermal conductivity of UO₂ nuclear fuel on surrogate material (CeO₂); the main focus of the research is given on the sintering behaviour of CeO₂. The incorporation of highly thermally conductive material (SiC) is the investigated concept of thermal conductivity enhancement. Conventional sintering and spark plasma sintering (SPS) were applied to compare the behaviour of CeO₂ and UO₂ reported in the literature. High temperature thermal conductivity measurements did not confirm the positive influence of SiC additive inside the CeO₂ matrix mainly due to grain boundary disruptions. Similar behaviour was also previously reported for UO₂ pellets with SiC.

KEYWORDS:

• CeO₂
• SiC
• nuclear fuel surrogate material
• thermal conductivity enhancement
• spark plasma sintering

ORCID

Štěpán Foral http://orcid.org/0000-0002-9606-7167

Karel Katovský http://orcid.org/0000-0001-9335-8199

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Czech Science Foundation (GACR) project no. P108/13-02476S; Ministry of Education, Youth and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601).