15.4 Developed Uranium-Free TRU Metallic Core
This chapter describes specifications for selection of a uranium-free TRU metallic
core and performance of the uranium-free TRU metallic core. Then, the core and
fuel are developed on the basis of those results and the feasibility of the developed
core is evaluated.
15.4.1 Specification Selected for Uranium-Free TRU
Metallic Core
On the basis of the results of the parametric surveys, the uranium-free TRU burning
core was specified as shown in Table 15.3 and Fig. 15.5. TRU-Zr alloy fuel pins and
BeO pins were employed to enhance the Doppler coefficient. The reason for
adopting the TRU-Zr alloy fuel is to use a simpler fuel fabrication method, that
is, injection casting, in contrast to a TRU-Zr particle fuel in a zirconium metal
matrix. Then, the zirconium content in TRU-Zr alloy was assumed to be limited
below 35 wt% to keep the melting point of the TRU-Zr alloy below 1,200
C to
prevent Am vaporization during injection casting [19]. The fuel pins and the BeO
pins were separately located in the fuel subassemblies (Fig. 15.6). The diameter of
fuel pins was reduced from 0.65 to 0.48 cm to compensate for the increase of the
average linear heat rate caused by employment of the BeO pins. Core height is
65 cm to reduce burn-up reactivity swing, whereas the core diameter was increased
from 180 to 250 cm to keep the linear heat rate of the fuel pin similar to the 93-cmheight core. The operation cycle length is 150 days, which can be controlled by
conventional control rods and fixed neutron absorbers.
Table 15.3 Specification of the uranium-free TRU metallic core
Items
Value
Reactor thermal power
714 MW
Operation cycle length
150 days
Fuel type
TRU-Zr alloy
Number of fuel pins per S/A
135
Fuel pin diameter
0.48 cm
Core diameter
250 cm
Core height
65 cm
Spectrum moderator
BeO pins in Fuel S/A (number of pins, 196)
TRU composition
LWR discharged
10 years cooled
15 Development of Uranium-Free TRU Metallic Fuel Fast Reactor Core
163
This chapter describes specifications for selection of a uranium-free TRU metallic
core and performance of the uranium-free TRU metallic core. Then, the core and
fuel are developed on the basis of those results and the feasibility of the developed
core is evaluated.
15.4.1 Specification Selected for Uranium-Free TRU
Metallic Core
On the basis of the results of the parametric surveys, the uranium-free TRU burning
core was specified as shown in Table 15.3 and Fig. 15.5. TRU-Zr alloy fuel pins and
BeO pins were employed to enhance the Doppler coefficient. The reason for
adopting the TRU-Zr alloy fuel is to use a simpler fuel fabrication method, that
is, injection casting, in contrast to a TRU-Zr particle fuel in a zirconium metal
matrix. Then, the zirconium content in TRU-Zr alloy was assumed to be limited
below 35 wt% to keep the melting point of the TRU-Zr alloy below 1,200
C to
prevent Am vaporization during injection casting [19]. The fuel pins and the BeO
pins were separately located in the fuel subassemblies (Fig. 15.6). The diameter of
fuel pins was reduced from 0.65 to 0.48 cm to compensate for the increase of the
average linear heat rate caused by employment of the BeO pins. Core height is
65 cm to reduce burn-up reactivity swing, whereas the core diameter was increased
from 180 to 250 cm to keep the linear heat rate of the fuel pin similar to the 93-cmheight core. The operation cycle length is 150 days, which can be controlled by
conventional control rods and fixed neutron absorbers.
Table 15.3 Specification of the uranium-free TRU metallic core
Items
Value
Reactor thermal power
714 MW
Operation cycle length
150 days
Fuel type
TRU-Zr alloy
Number of fuel pins per S/A
135
Fuel pin diameter
0.48 cm
Core diameter
250 cm
Core height
65 cm
Spectrum moderator
BeO pins in Fuel S/A (number of pins, 196)
TRU composition
LWR discharged
10 years cooled
15 Development of Uranium-Free TRU Metallic Fuel Fast Reactor Core
163