ANALISIS POTENSI PROSES CREEP (PEMULURAN) TEHADAP BAHAN BAKAR UJI AKIBAT DISTRIBUSI STRAIN (KETEGANGAN) DENGAN MENGGUNAKAN PROGRAM FEMAXI

Abstract

Analysis of creep process potential of test fuel due to strain distribution has been carried out using FEMAXI program. The purpose of this study is to predict the possibility of creep of test fuel due to circumocular distribution of axial and radial strain at certain operating temperatures and times and to provide information on quality standards during production and operation of pin tests in the reactor core. This analysis is important because cladding is a barrier to the pressure release of fission gas products produced when the fuel is irradiated. The phenomenon of the total creep process on pin cladding is assumed to be caused by the effect of burn-up on the release of fission gas products, which results in pressure induced by strain of cladding at relatively high temperatures. The creep rate will increase with increasing strain. The total mechanical analysis of the top  and inner  part of fuel pins at steady operating conditions shows that there is an increase in creep depending on the LHR (linear heat rate) and operating pattern on the reactor core. For transient operating conditions, it shows an increase in stable creep. In ramp operating conditions or sudden LHR change operations, it indicates an increase in creep processes due to difference in strain pressures between steady operation patterns, transients and ramps during the process of creep on pellets and cladding. This is due to fission gas products, but the final results of the total pin condition calculation indicate that the pin products are still considered as safe in terms of both thermal and mechanical processes with various patterns of LHR changes.