A neutron transport and thermal hydraulics coupling scheme to study xenon induced power oscillations in a nuclear reactor

A multi-physics computational methodology to analyze xenon induced power oscillations in a nuclear reactor is developed and presented. The methodology development takes into account both neutron transport and thermal hydraulics behaviors and their inter-dependent feedbacks in a nuclear power reactor as a function of fuel burn-up. The methodology uses the Monte Carlo N-Particle radiation transport computational code (MCNP6) along with its fuel transmutation module (CINDER90), a semi-analytic single channel analysis tool for thermal hydraulics and the SIGACE code suite for temperature dependent neutron interaction cross section processing. A Python script developed couples the physics codes for full automation. The accuracy of the multi-physics computational methodology developed was verified through a benchmark calculation for the published core parameters of a startup test performed at Yonggwang Power Reactor Unit No. 3. The power axial offset and xenon axial offset parameters were calculated for this benchmark case and used to quantify the oscillatory behavior observed, the results of this benchmark study is also presented here. The results showed that the developed methodology was able to capture the underlying phenomena governing xenon induced power oscillations in a nuclear reactor.