Development of Kinetics Model for BWR Core Simulator AETNA

An adiabatic kinetics model has been developed for a BWR core simulator AETNA. A few-energy-group analytic polynomial nodal diffusion method consistent with its steady-state solution has been adopted for spatial solution. The frequency transform method has been introduced to reduce computing time during the transient. The AETNA solution efficacy has been evaluated through comparison of the results with other codes using established benchmark problems. In particular, AETNA has shown a good agreement with QUANDRY, i.e., almost the same accuracy as other codes with regard to power or power density, peak time and fuel temperature. The computing time is reduced to less than one-ninth in no feedback cases and less than one-third in a Doppler feedback case when applying the frequency transform method.