The effect of material property variations on the failure probability of an AGR moderator brick subject to irradiation induced self stress

The failure of graphite moderator bricks in an Advanced Gascooled Reactor (AGR) is potentially a serious problem. This thesisdescribes the generation of self stress in the moderator brick during irradiation and the derivation of a simple analytical model to predict the magnitude of this stress. The magnitude of the selfstress in the brick is affected by the variations in the materialproperties of the graphite used for the brick and this is alsoexamined, developing a statistical approach to the analysis.Property variations between bricks are considered but no allowancehas been made for material property variations within a brick.Finally, the thesis compares the self stress in one of the criticalpeak rated moderator bricks to the strength of the irradiatedoxidised material on a statistical basis and predicts the failureprobability of a brick due to self stress to be extremely low at 25.5 full power years (FPY). However, the failure probability risessteeply and for the peak rated bricks at 29 FPY it approaches 100%.

Level dc:type.qualificationlevel

Doctoral (Level 8)

Year dc:date.issued

1989

Author dc:creator

• Preston, SD

Language dc:language

en

Identifier

oai:salford-repository.worktribe.com:1389518

OAI identifier oai:identifier

oai:salford-repository.worktribe.com:1389518