Analysis of the SPERT-III E-Core Using ANCK Code with the Chord Weighting Method

ANCK/MIDAC is a three-dimensional (3D) code system that has been developed, which couples the 3D nodal kinetic code ANCK and the 3D drift flux thermal-and-hydraulics (T/H) code MIDAC. The adequacy of the ANCK feedback model was confirmed by analysis of the SPERT-III E-core reactivity accident tests. The chord weighting method was adopted in the effective fuel temperature (Teff) calculation model of ANCK and ANCK/MIDAC since it provides results that are in good agreement with those of a Monte Carlo calculation. The adequacy of the Teff model was also confirmed. The calculation results for hot startup and hot standby conditions using the ANCK code showed excellent agreement for the main parameters such as peak power, peak time, and behavior of reactor power. It was also confirmed that the ANCK feedback model with the chord weighting method was applicable to the reactivity-initiated accident (RIA) calculation for the case of 4.8 wt% UO2 core.