[3J12-14] Criticality Safety

[3J13] Effect of Gd₂O₃ to a fission number in the first pulse of a postulated nuclear excursion

*Irwan Liapto Simanullang¹, Yuichi Yamane¹, Kotaro Tonoike¹ (1. JAEA)

Keywords:burnable poison, temperature coefficient, fission number, Nordheim-Fuchs model

In criticality safety design, UO₂ fuel models without burnable poison (BP) are generally used, which gives higher keff values and is conservative. In the current study of criticality accident analysis, BP has been taken account into calculations, which decreases reactivity temperature coefficients and increases fission numbers.