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D2O-moderated 235UO2-ThO2 critical lattices (Th5-HW/CRITD2O)

9.01) Th5HW-AECLZED2

Analysis of Lattice Experiments with 19-rod Clusters with ThO2-UO2 Fuel

Measurements were made with ThO2 fuel containing 1.5 w% enriched UO2 (93.02 atm % U235)
using heavy water and air coolants. Buckling measurements were performed at four triangular
lattice pitches of 22, 24, 28 and 32 cm and detailed reaction rate measurements were carried out
at 22 and 28 cm only.

Pitch (cm) zed2t4d22,a22: 22.0
zed2t4d28,a28: 28.0
Lattice geometry Hexagonal
Coolant zed2t4d22,d28: D2O
zed2t4a22,a28: Air
Moderator D2O
Number of rods 19 (1/6/12)
Radius of rod centers (cm) 0.0/1.468/2.837
Fuel material [ThO2(98.5w%)]-[UO2-93at%(1.5w%)]
Density of fuel material (g/cm3) 9.33
Radius of fuel rods (cm) 0.5765
Sheath material Zry-2
Density of sheath material (g/cm3) 6.55
Internal radius of sheath (cm) 0.5815
Thickness of sheath (cm) 0.0406
Material of coolant tube Alcan 6068 Al alloy
Density of coolant tube (g/cm3) 2.7
Internal radius of coolant tube (cm) 3.683
Thickness of coolant tube (cm) 0.127
Temperature (K) 294.8
Experimental bucklings
zed2t4d22: 0.00024
zed2t4a22: 0.00023
zed2t4d28: 0.00015
zed2t4a28: 0.00016


[1] OKAZAKI, A., DURRANI, S.A., AECL-2778,1967.

[2] OKAZAKI,A., AECL- 2779,1968.

[3] KRISHNANI, P.D., Analysis of Lattice Experiments with ThO2-UO2 Fuel using WIMS

Library, Ann.nucl.Energy,Vol.16,No.3,pp.151-155,1989.