Numerical Simulations and Design Optimization of the PHT Loop of Natural Circulation BWR

Table 3

Design parameters at minimum material condition.

Parameter	Design 1	Design 2	Design 3
Pressure	70 bar	70 bar	70 bar
Power	220 MW	220 MW	220 MW
Core inlet enthalpy	1204.8 kJ/kg	1204.8 kJ/kg	1204.8 kJ/kg
Factor of safety	1.4	1.4	1.5
Mass flux	1000 kg/m^2-s	800 kg/m^2-s	1000 kg/m^2-s
Coolant channel diameter	0.1076 m	0.1128 m	0.1105 m
Active core length	3.8262 m	3.389 m	6.1964 m
Riser diameter	0.1018 m	0.1063 m	0.1277 m
Riser length	27.5323 m	20.0 m	28.3428 m
Area of the downcomer	0.1007 m^2	0.1011 m^2	0.1381 m^2
Diameter of the fuel rod	0.011 m	0.011 m	0.011 m
Number of coolant channels	113	113	113
Number of fuel rods	54	54	54
Volume of material	4.0 m^3	3.1138 m^3	5.9441 m^3
Core exit void fraction	0.8034	0.8025	0.778
Stability margin	0.0902 s^−1	0.1069 s^−1	0.1481 s^−1