Table 1: Monju main data

1 January 2000


Reactor type: Sodium-cooled, loop-type fast breeder reactor
Purpose: Development of FBRs/power generation
No. of loops: 3
Thermal output: 714 MWt
Electrical output: 280 MWe
Reactor vessel type: Cylindrical with end plate at the bottom
Reactor vessel dimensions: Height 18m; diameter 7m
Core/fuel
Core dimensions: Height 179cm; diameter 93cm
Fuel composition: Pu-U mixed oxide
Percentage Pu enrichment (inner core/outer core): 16/21
Fuel inventory: Core (U+Pu) 5.9t; Blanket (U) 17.5t
Average fuel burnup: 80,000 MWd/t
Breeding ratio: 1.2
Fuel assemblies
No. of fuel assemblies: 198
No. of fuel pins per assembly: 169
Length of fuel pin: 2.8m
Length of fuel assembly: 4.2m
No. of blanket assemblies: 172
No. of fuel pins per blanket assembly: 61
Control rods
No. of control rods: 13 (main shutdown system); 6 (backup system)
No. of control elements per rod: 19
Effective height of absorber: 0.93m
Control element material: Boron carbide (B4C)
Primary heat transport system
Coolant: Sodium
Sodium mass: 760t
Flow rate per loop: 5.1x106 kg/hour
Flow velocity (reactor inlet/outlet): 6m/s; 4m/s
Primary sodium temperature (reactor inlet/outlet): 397/505°C
Secondary heat transport system
Coolant: Sodium
Sodium mass: 760t
Flow rate per loop: 3.7x106 kg/hour
Flow velocity: 5m/s
Secondary sodium temperature (the IHX inlet/outlet): 325/505°C
Water-steam system
Feedwater flow rate: 113.7x104 kg/hour
Steam temperature (turbine inlet): 484°C
Steam pressure (turbine inlet): 12.7MPa
Type of steam generator: Helical coil
Refuelling system
Type: Single rotating plug with fixed arm FHM
Refuelling interval: 6 months



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