Table 11: Coolant void reactivity and fuel temperature coefficient for ATF.

DescriptionEnrichment
(wt%  235U)
Fresh fuel
Fresh fuelMidburnup
CVRFTCCVRFTC
(mk)(pcm/K)(mk)(pcm/K)

UO20.711%1.11850
1.300%1.35036

UO2 + 3% SiC0.720%1.12319
1.320%1.35597

UO2 + 6% SiC0.720%1.12203

UO2 + 10% SiC0.730%1.12577

UN0.711%1.11918
1.220%1.32137

UN + 3% U3Si20.711%1.11907

UN + 6% U3Si20.711%1.11929

UN + 10% U3Si20.711%1.11905

UN + 10% ZrN0.711%1.11744

U-9Mo0.930%1.12952

UO2 FCM in SiC
35% packing fraction
1.070%1.18147
1.890%1.41177

UO2 FCM in SiC
40% packing fraction
1.010%1.17808
1.620%1.37165
1.800%1.41008

UO2 FCM in SiC
45% packing fraction
0.950%1.16881
1.430%1.33787

UO2 FCM in SiC
50% packing fraction
0.910%1.16434
1.280%1.30639

UO2 FCM in SiC
55% packing fraction
0.880%1.16149
1.160%1.27726

UO2 FCM (650 μm) in SiC
40% packing fraction
1.010%1.17804
1.620%1.37161

UO2 FCM (750 μm) in SiC
40% packing fraction
1.010%1.17809
1.620%1.37170

UN FCM in SiC
35% packing fraction
0.930%1.16290
1.280%1.29615

UN FCM in SiC
40% packing fraction
0.890%1.15883
1.130%1.25901

UN FCM in SiC
45% packing fraction
0.850%1.15066
1.020%1.22738

UN FCM in SiC
50% packing fraction
0.820%1.14447
0.930%1.19745

UN FCM in SiC
55% packing fraction
0.800%1.14123
0.970%1.17653

UN FCM in SiC
55% TRISO packing fraction
2.250%1.46143

UO2 + 3% SiC
zircaloy cladding
0.720%1.12319

UO2 + 3% SiC
SiC cladding
0.711%1.12010

UO2 + 3% SiC
zircaloy + FeCrAl cladding
0.790%1.12855