PROCEEDINGS OF IBRAE RAS, ISSUE 5: MODELS FOR FISSION PRODUCTS RELEASE FROM IRRADIATED UO2 FUEL

Ed. by L.A. Bolshov, R.V. Arutyunyan

The main models of the mechanistic code MFPR are described. Exhaustive description of fissiongas behaviour in grain and out of grain is given in relation with individual validation results on analytical experiments under various conditions (steady irradiation, transient, post-irradiation annealing).
It is shown that microscopic defects in the UO2 crystal structure can strongly influence fissiongas transport out of grains and release from fuel pellets.

The mechanistic description of chemicallyactive-elements behaviour is also presented. It is based on complex association of diffusionvaporization
mechanism involving multi-phase and multi-component thermo-chemical equilibrium at the grain boundary with accurate calculation of fuel oxidation. Examples of application to integral experiments performed at high temperatures in oxidising and oxidising/reducing gas atmospheres, show the possibilities of the code in the frame of severe-accident interpretation. 

The assumed target for the issue are students and specialists in nuclear materials research and NPP safety analysis.

Bibliographical reference

Nuclear Safety Institute (IBRAE) RAS. — Moscow: Nauka, 2007— .Issue 5 : Models for Fission Products Release from Irradiated UO2 Fuel / Ed. by R.V. Arutyunyan. — 2008. — 157 p. : ill. — ISBN 978-5-02-036951-1 (bound).