Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Examination of Heat Transfer in Ceramic Fuel Elements at Variable Thermal Loadings

7/14/2012 2012 - #02 Thermal physics and thermal hydraulics

Popov V.V. Rumyantsev V.N. Kurina I.S. Mikheev M.V.

DOI: https://doi.org/10.26583/npe.2012.2.14

UDC: 621.039.548

The technique of measurement, under laboratory conditions, of contact pressure and heat conductance from UO2 fuel pellets to fuel cladding at power variation is described. As has been shown, from the moment as a certain level of power is achieved, fuel sleeves go on cracking, so the radial gap between their fragments and cladding is being reduced up to the mechanical contact of sleeve fragments to cladding, and the contact pressure increases with the growth of level and amount of power variation cycles. The results of the analysis of computational models for heat transfer from fuel to cladding are also presented and discussed.