MOX fuel microstructural evolution during the VERDON-3 and 4 tests

JOURNAL OF NUCLEAR MATERIALS

卷:531

Article

Le Gall, C.¹  Reboul, S.¹  Fayette, L.¹  Blay, T.¹  Zacharie-Aubrun, I¹  Felines, I¹  Hanifi, K.¹  Roure, I¹  Bienvenu, P.¹  Audubert, F.¹  Pontillon, Y.¹  Hazemann, Jean-Louis^2,3 

[1] CEA, DEC, DEN, F-13108 St Paul Les Durance, France

[2] CNRS UGA, Inst Neel, F-38041 Grenoble 9, France

[3] ESRF, CRG Fame, F-38000 Grenoble, France

关键词: MOX irradiated fuel;    Fuel behaviour;    Light water reactor (LWR);    Severe accident;    VERDON tests;    Post-test characterisations;    Fuel-cladding interaction;   

DOI  :  10.1016/j.jnucmat.2020.152015

来源: Elsevier

【 摘 要 】

The VERDON-3 and -4 tests were part of the VERDON-ISTP programme that aimed at studying the fuel and fission products (FP) behaviour in severe accident conditions. The main objective of these two complementary tests was the study of MOX fuel behaviour and FP release under oxidising (VERDON-3) and reducing (VERDON-4) conditions at very high temperature (>2300 degrees C). Complementary to the online gamma spectrometry measurements performed during the two tests, post-test characterisations were carried out in order to tackle these tasks. The two samples recovered after the VERDON-3 and -4 tests were compared to a third one extracted from the same father rod and left as irradiated. This comparison enabled to highlight the effect of temperature and atmosphere on the fuel behaviour. These three samples were characterised by several techniques available at the LECA-STAR facility of the CEA Cadarache. Experimental observations showed that an interaction between the fuel and the cladding occurred in both types of conditions by interdiffusion mainly between U and Zr. This phenomenon led to the formation of a UyZr1-yO2 +/- x cubic phase at the periphery of the fuel pellet which melted in the VERDON-4 test conditions, penetrating through the cracks of the sample and dissolving the fuel matrix. No liquid was formed during the VERDON-3 test despite the formation of a large fuel-cladding interaction zone. (C) 2020 Elsevier B.V. All rights reserved.

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