Study of heterogeneity effects on the sodium void coefficients (2)

Kobayashi, Takatoshi*; Sugawara, Akira*; Seki, Yuji*; Ikezawa, Hiroko*

As a continuation of the previous research, heterogeneity effects of neutron spectra and axial leakage have been examined. Spectra in a two-region cell were computed by a collision probability method and the heterogeneity effect was found to be small. The analysis of the axial leakage was carried out with the benoist's directional collision probability method and it turned out that the heterogeneity has negative contribution to the sodium void coefficient. Combining the results of the previous research and the current one, the heterogeneous void coefficient in a prototype fast reactor moves towards the positive direction from the homogeneous result.