RELAP5 Analyses of ROSA/LSTF Experiments on AM Measures during PWR Vessel Bottom Small-Break LOCAs with Gas Inflow

Table 4

High-ranked phenomena and relevant key parameters identified.

Component	Phenomenon	Parameter
Break	Critical flow	Discharge coefficient through break
Fuel rods	Decay heat	Core decay power
Core	Two-phase mixture level	Gas-liquid inter-phase drag in core
Cold legs/ACC or LPI system	Steam condensation on ACC or LPI coolant	Gas-liquid inter-phase heat transfer in cold legs
SG U-tubes	Steam condensation under noncondensable gas accumulation	Condensation heat transfer in SG U-tubes under steam-gas mixture condition
SG valves for depressurization	Steam discharge	Discharge coefficient through SG valves