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DHC Initiation at Volumetric Flaws

Chapter
Part of the Engineering Materials book series (ENG.MAT.)

Abstract

Threshold conditions for DHC initiation at volumetric flaws—which require a different treatment than is appropriate for DHC initiation at cracks—is summarized in this chapter. The initial approach, based on a peak stress threshold criterion, resulted in this threshold decreasing with the number of reactor shutdown cycles. This was found to be too restrictive on reactor operation. Moreover, the method did not have an explicit dependence on flaw geometry (root radius) nor could it readily be used to assess the DHC initiation potential of sharp secondary flaws at the root of blunt flaws. The hydride process zone model that was developed to eliminate these deficiencies of the peak threshold stress model is described in this chapter. Details of the validation procedures of the engineering process zone model in relation to the experimental data base for DHC initiation from blunt flaws in unirradiated and pre-irradiated Zr–2.5Nb pressure tube material are given.

Keywords

Stress Intensity Factor Process Zone Threshold Stress Threshold Condition Pressure Tube 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag London 2012

Authors and Affiliations

  1. 1.MPP ConsultingOakvilleCanada

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