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

Preston, SD

Abstract

The failure of graphite moderator bricks in an Advanced Gas
cooled Reactor (AGR) is potentially a serious problem. This thesis
describes 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 self
stress in the brick is affected by the variations in the material
properties of the graphite used for the brick and this is also
examined, developing a statistical approach to the analysis.
Property variations between bricks are considered but no allowance
has been made for material property variations within a brick.
Finally, the thesis compares the self stress in one of the critical
peak rated moderator bricks to the strength of the irradiated
oxidised material on a statistical basis and predicts the failure
probability of a brick due to self stress to be extremely low at 25.5 full power years (FPY). However, the failure probability rises
steeply and for the peak rated bricks at 29 FPY it approaches 100%.

Citation

Preston, S. The effect of material property variations on the failure probability of an AGR moderator brick subject to irradiation induced self stress. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Jul 14, 2017
• Publisher URL: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261920
• Related Public URLs: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261920
• Award Date: Apr 1, 1989