Discussion

J.F.W. BISHOP UKAEA In addition to the inforamtion in the paper I am able to inform you that among our recent irradiations in DFR we now have three experimental subassemblies with more than 10% peak burnup. Also recently a trefoil rig with three pins at 14|% burnup is apparently in good condition.

K.KUMMERER GkF Karlsruhe Was UO2 swelling observed in the adjacent axial breeder pellets due to caesium migration into the axial blanket?

J.F.W. BISHOP Instances of reaction involving swelling of dense U0 pellets in direct contact with mixed oxide

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have been seen on a few occasions, particularly when the fuel rating has been high. Our PFR irradiations will cover both direct breeder/core fuel contact and a spacer separating the two