Hybrid microscopic depletion model in nodal code DYN3D

Abstract

 A new hybrid method of accounting for spectral history effects is proposed.  Local concentrations of over 1000 nuclides are calculated using micro depletion.  The new method is implemented in nodal code DYN3D and verified.

Explicit decay heat calculation in the nodal diffusion code DYN3D

“…history of the local temperatures, power and control rod insertion during the fuel burnup). To account for the actual local nodal nuclide content, a hybrid microscopic depletion method was recently developed and implemented in DYN3D (Bilodid et al, 2016). DYN3D obtains the local nuclide content for each node at the end of each time step ∆ by solving the full set of Bateman equations in matrix form by computing the matrix exponential:…”

“…The power history and variation of coolant density is shown in Fig. 7 (top were performed employing the pre-generated macro-and microscopic XS corrected using the hybrid micro-depletion method (Bilodid et al, 2016).…”