Proposal for Increase of Thermal Margin in COLSS

One of the moot important constants to be Installed In COLSS, a monitoring system in CE typed reactors, is ROPM which would limit the operating space. This static ROPM was calculated from digital transient analysis assuming that every design basis transient was initiated from the most severe initial condition combination (LCO). Once It could be assured that core condition would not be located at none other than LCO, this static ROPM could be replaced with dynamic ROPM calculated at that condition and the dynamic ROPM would be definitely less than the static ROPM. In order to do, It must be required to calculate the transient discrete sensitivity parameters and parameters change distribution. The purpose of this report is just to propose the enlargement method for thermal margin.