Experimental investigation on the causes for pellet fragmentation under LOCA conditions

JOURNAL OF NUCLEAR MATERIALS

卷:465

Article

Bianco, A.^1,2  Vitanza, C.³  Seidl, M.^1,2  Wensauer, A.¹  Faber, W.¹  Macian-Juan, R.² 

[1] E ON Kernkraft GmbH, D-30457 Hannover, Germany

[2] Tech Univ Munich, Lehrstuhl Nukl Tech, D-85748 Garching, Germany

[3] Inst Energiteknikk, NO-1777 Halden, Norway

关键词: Nuclear fuel;    LOCA;    Fragmentation;    Fission gas release;    Halden Reactor Project;   

DOI  :  10.1016/j.jnucmat.2015.05.035

来源: Elsevier

【 摘 要 】

This paper addresses a separate effect experiment performed with irradiated fuel to study fuel fragmentation and fission gas release during a loss of coolant accident (LOCA). The paper presents a qualitative and quantitative investigation of the effects of the removal of the geometrical constraint provided by the cladding and the removal of the constraint given by the rod internal pressure in determining the extent of fuel fragmentation and fission gas release during a LOCA for fuel segments with a burnup of approximately 52 MWd/kgU. A review of previous LOCA tests was the starting point for the identification of these constraints and for the selection of the fuel rod burnup, the experiment's procedure and the boundary conditions. An out-of-pile test was considered representative for the scope, and the experiment was performed at the Halden Reactor Project hot cell in Kjeller (Norway) with heat provided by an electric oven. Three fuel rod segments were studied: 1) a fuel segment that experienced only ballooning without burst, 2) a fuel segment that experienced ballooning and burst and 3) a fuel segment that experienced neither ballooning nor burst. The neutron radiography and fuel fragment sifting showed that both cladding constraint and internal pressure play a role in the formation of fuel cracks and fragmentation, and the study of the fission gas release during the transient showed that removing the cladding constraint or the internal pressure increased the amount of fission gas release. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free