Two group, three dimensional diffusion theory coupled with single heated channel model: A study based on xenon transient simulation of Tehran research reactor

In this work xenon transient analysis of the Tehran research reactor (TRR) core from hot full power without poisoning to xenon saturation is carried out using neutronic and thermal hydraulic coupling. A complete two group, three dimensional neutronic model coupled with one dimensional single phase heat transfer model has been developed and applied to power distribution calculations. We used the WIMS-D5 cell calculation code in order to find a linear relation between important parameters (fuel temperature, moderator temperature and density, and xenon concentration) and group constants of different fuel assemblies. In this way, WIMS running will be bypassed at each time step. We developed and used the ANOMOS code that solves three dimensional diffusion equations using analytic nodal method by transverse leakage approximation in order to find the effective multiplication factor as well as flux and power distributions. Also, we developed and used a SHC code that solves the conservation equations for one dimensional axial homogeneous downward flow through channel using single heated channel model to find the assembly-wise fuel temperature, moderator temperature and density profiles versus generated power. The results have a good agreement with the safety analysis report of the TRR.