International Conference on the Physics of Reactors “Nuclear Power: A Sustainable Resource” Casino-Kursaal Conference Center, Interlaken, Switzerland, September 14-19, 2008
A semi-analytic solution of the P3 equation is obtained employing the two-node configuration for use in the
solution of the axial angular flux variation in a whole core transport calculation scheme. For the semi-analytic
solution, all the source terms are moved to the right hand side and then approximated by a quartic Legendre
polynomial so that the analytic solution is represented by exponential and polynomial functions. It turns out that
the exponential shape captures very well the severe variation of the second angular flux moment near the
interfaces of different materials which would not be possible with the nodal expansion method solution. On the
other hand, the coarse mesh finite difference formulation which is applicable for the P3 equation without causing
the instability associated with largely fluctuating variation of the second angular moment flux with alternating
signs is proposed. The performance of the proposed SANM-CMFD solution scheme is examined for simplified
model problems constructed using the L336 C5 MOX and UOX cross sections.
