• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.29 no.3
• /
• pp.245-252
• /
• 2016

The development of Top-Mounted In-Core Instrumentation(TM-ICI) is an ongoing project to reduce the risk due to severe accidents by inserting the instrumentation into a reactor closure head instead of a reactor bottom head. As part of this project, environmental fatigue analyses for TM-ICI nozzle have been performed using two methods of NUREG/CR-6909 and Code Case N-761. TM-ICI nozzle is subjected to transient loads for level A, level B and test conditions that should be evaluated for a fatigue analysis. It is found that a cumulative usage factor considering reactor coolant environment for TM-ICI nozzle is evaluated as less than 1, which is ASME Code allowable criteria of a fatigue analysis.