Examination of the irradiated mixed carbide and nitride fuels as part of their safety evaluation

The NIMPHE 2 rods are fast breeder reactor fuel rods prepared together with CEA in a joint project. Sets of pins were prepared at both CEA Cadarache and at JRC-ITU Karlsruhe before being irradiated together in the Phénix reactor. The pins were then returned to their respective institutes for examination. This paper describes the full non-destructive and destructive examinations of the 25%Pu- containing carbide and nitride fuel pins prepared by JRC-ITU. They showed an excellent behaviour up the final burn-up of close to 5.8 atomic %. The fission gas release to the plenum appeared to be reasonable, in comparison with previous results. The non-destructive testing indicated a good condition and reasonable fission gas release, but suggested cladding corrosion. However the metallographic examinations of the rod indicated good performance with only traces of internal attack or external coolant attack. The porosity of both nitride and carbide fuel at the mid-height was substantial and accumulated in the centre with carbide showing a slightly greater swelling. Further detailed testing will be carried out on the fuel micro-structure, particularly to determine the distribution of retained gas in the fuel and comparison with the CEA rods behaviour.

BOTTOMLEY Paul;  PAPAIOANNOU Dimitrios;  NASYROW Ramil;  DE WEERD Wim;  RONDINELLA Vincenzo; 

2015-09-08

Deutsches Atom Forum (DAtF)

JRC95858

http://www.kernenergie.de/kernenergie/service/veranstaltungen/tagungen/2015-05-05_jahrestagung.php,    https://publications.jrc.ec.europa.eu/repository/handle/JRC95858,