Ohma full-MOX reactor starting in 2014 in this analysis can be operated only by
MOX fuel. Because the RRP is operated after all LWRs are closed, part of the
separated Pu cannot be burned. The total amount of Pu is reduced to 250 t, but that
of MA is increased to 100 t.
19.4.3 Result of FR
In the FR scenario as well as other transmutation scenarios, Pu from the RRP is at
first fabricated as LWR-MOX fuel and burned in LWR. Pu is co-extracted with
same content of U in the current RRP, although MA is vitrified as waste. MA
partitioning is assumed to be introduced in 2025 and stored until 2045. In 2045,
before introduction of transmuters in 2050, reprocessing of LWR-MOX spent fuel
will begin and provide Pu to the transmuters.
FRs are to be introduced in 2050 when 250 t plutonium and 100 t MA remains.
MA of 20 t is vitrified by the RRP before 2025 and is not available for transmutation. Available TRU is 330 t. The required TRU to introduce an FR is approximately 25 t, if we assume 41 % of Pu content and 15 % of MA content and employ
45.1 t from Table 19.10. Theoretically, 14 (¼350/25) FRs can be introduced in
2050, but only 8 can be deployed in practice because the plant life of an FR is
assumed to be 60 years and sufficient TRU must be kept until 2110. Available TRU
gradually decreases to 200 t in 2110 by transmutation. After 2110, FRs are replaced
and reduced to 3 units corresponding to available TRU of 200 t that decreases to
130 t in 2170. Then, 2 FRs from 2170 to 2230 and 2 FRs from 2230 to 2290 will be
deployed. After four generations of transmutation, the amounts of Pu and MA are
reduced to 40 and 30 t, respectively.
MA content of FR is as high as 15 % (Fig. 19.7), which is above the design limit
of 5 % in Wakabayashi et al. [1]. In the usual design of FBRs, MA accumulation is
mitigated by a supply of fresh Pu from the blanket. Moreover, high Pu content of FR
burner contributes to high MA content. High MA content generally causes deterioration of safety parameters (beta, Doppler coefficient, void reactivity) and difficulty in a reprocessing and fabrication plant.
19.4.4 Result of ADS
In the ADS scenario, transmuter is changed from FR to ADS. ADS can accept
both Pu and MA; distribution is shown in Fig. 19.8. In 2050, 22 ADSs are to be
introduced, corresponding to 140 t available TRU. Then, 7 and 3 ADSs are
operated respectively from 2110 to 2170 and 2170 to 2230. After three generations, Pu and MA are reduced to 10 t and 3 t, respectively, excluding 16 t MA in
vitrified waste.
19 Transmutation Scenarios after Closing Nuclear Power Plants
221
MOX fuel. Because the RRP is operated after all LWRs are closed, part of the
separated Pu cannot be burned. The total amount of Pu is reduced to 250 t, but that
of MA is increased to 100 t.
19.4.3 Result of FR
In the FR scenario as well as other transmutation scenarios, Pu from the RRP is at
first fabricated as LWR-MOX fuel and burned in LWR. Pu is co-extracted with
same content of U in the current RRP, although MA is vitrified as waste. MA
partitioning is assumed to be introduced in 2025 and stored until 2045. In 2045,
before introduction of transmuters in 2050, reprocessing of LWR-MOX spent fuel
will begin and provide Pu to the transmuters.
FRs are to be introduced in 2050 when 250 t plutonium and 100 t MA remains.
MA of 20 t is vitrified by the RRP before 2025 and is not available for transmutation. Available TRU is 330 t. The required TRU to introduce an FR is approximately 25 t, if we assume 41 % of Pu content and 15 % of MA content and employ
45.1 t from Table 19.10. Theoretically, 14 (¼350/25) FRs can be introduced in
2050, but only 8 can be deployed in practice because the plant life of an FR is
assumed to be 60 years and sufficient TRU must be kept until 2110. Available TRU
gradually decreases to 200 t in 2110 by transmutation. After 2110, FRs are replaced
and reduced to 3 units corresponding to available TRU of 200 t that decreases to
130 t in 2170. Then, 2 FRs from 2170 to 2230 and 2 FRs from 2230 to 2290 will be
deployed. After four generations of transmutation, the amounts of Pu and MA are
reduced to 40 and 30 t, respectively.
MA content of FR is as high as 15 % (Fig. 19.7), which is above the design limit
of 5 % in Wakabayashi et al. [1]. In the usual design of FBRs, MA accumulation is
mitigated by a supply of fresh Pu from the blanket. Moreover, high Pu content of FR
burner contributes to high MA content. High MA content generally causes deterioration of safety parameters (beta, Doppler coefficient, void reactivity) and difficulty in a reprocessing and fabrication plant.
19.4.4 Result of ADS
In the ADS scenario, transmuter is changed from FR to ADS. ADS can accept
both Pu and MA; distribution is shown in Fig. 19.8. In 2050, 22 ADSs are to be
introduced, corresponding to 140 t available TRU. Then, 7 and 3 ADSs are
operated respectively from 2110 to 2170 and 2170 to 2230. After three generations, Pu and MA are reduced to 10 t and 3 t, respectively, excluding 16 t MA in
vitrified waste.
19 Transmutation Scenarios after Closing Nuclear Power Plants
221