Silicon carbide encapsulated fuel pellets for light water reactors

In this paper a new fuel element concept is proposed. In addition to the cl adding tube the fuel is encapsulated in SiC capsules. The basis of the conc ept is a bonding technique that allows to join SiC without loosing the exce llent features of the SiC base material like high mechanical strength and g ood oxidation resistance. The results of different tests and calculations p erformed in the on-going R&D program with regard to the mechanical, thermal , chemical and neutron-physical behaviour have shown that this fuel element concept fulfils the safety requirements like negative fuel temperature coe fficient and negative moderator void coefficient. Furthermore the maximum f uel temperatures can be reduced. Due to a new developed joining technique, which is one of the major topics of the R&D program the density of the cera mic encapsulation remains unchanged as well during irradiation tests as und er oxidation and thermal shock loading conditions. (C) 2001 Elsevier Scienc e Ltd. All rights reserved.