Abstract
Acoustic emission (AE) responses from unirradiated nuclear graphites subject to cyclic loading have been shown to exhibit the Felicity effect, i.e., AE is detected at stresses below the previous peak stress. This has been attributed to time dependent recovery processes which occur upon unloading and at zero stress [1]. This paper describes work comparing similar unirradiated and irradiated nuclear sleeve graphites. The number of AE event counts from irradiated graphite was shown to be greater than that from unirradiated graphite, subjected to similar stresses. This effect was attributed to the increase in porosity caused by radiolytic oxidation. A Felicity effect was observed on cyclic loading of irradiated graphite, but no evidence for a Kaiser effect was found for irradiated graphite loaded monotonically to failure. The absence of a Kaiser effect can be attributed to relaxation and recovery processes that occur in the considerable time interval between removing the irradiated graphite from the reactor and post-irradiation examination. Therefore, it was concluded that AE monitoring is not a suitable technique for measuring internal stresses in irradiated graphites.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
