Based on the foregoing assumptions, operation efficiency and cycle efficiency
are determined as listed in Table 19.7, with specific heat and resulting transmutation half-life. Operation efficiency multiplied by cycle efficiency of the Pu-ADS is
the poorest, but the transmutation half-life is the shortest because of the high
specific heat. In the present study, a 30-day interval for fuel exchange is adopted
as a nominal case. The transmutation half-life of the Pu-ADS is 24.8 years in the
nominal case, which is applied to scenario analysis.
Another observation is that the impact of the out-core period on cycle efficiency
is significant. The out-core period is presumed considering the half-life of
242 Cm of
126.8 days. If a shorter out-core period is accomplished by corresponding design of
the reprocessing and fabrication plant, cycle efficiency and resulted transmutation
half-life can be improved. Table 19.8 shows comparison of a 3-year and 1-year
out-core period. An impact on the transmutation half-life of the Pu-ADS is a factor
of around 2, and the transmutation half-life becomes as short as 13.5 years.
Although 3 years of out-core period is applied as the nominal case, a shorter
out-core period should be pursued in future study.
Table 19.7 Assumption on maintenance schedule versus transmutation half-life for six-batch
design (equilibrium core)
ADS case
MA
Pu
Pu + U
Interval case 2 Â 65 days 15 Â 5
+ 60 Â 1
30 Â 5
+ 60 Â 1
60 Â 5
+ 60 Â 1
15 Â 4
+ 60 Â 2
30 Â 4
+ 60 Â 2
60 Â 4
+ 60 Â 2
Batch
1
6
6
6
6
6
6
Operation
(days)
600
a
50
50
50
100
100
100
Short interval (days)
b
15
30
60
15
30
60
Long interval
(days)
c
130
a
60
60
60
60
60
60
ε o (%)
82
69
59
45
77
71
63
In-core
period
(years)
2
1.19
1.40
1.81
2.01
2.22
2.63
Out-core
period
(years)
3
3
3
3
3
3
3
Ε c (%)
40
28
32
38
40
43
47
Ε o *ε c (%)
33
20
19
17
31
30
29
h (MW/tHM) 182
393
393
393
151
151
151
λtr (/years)
2.28E-02
2.93E02
2.79E02
2.55E02
1.78E02
1.75E02
1.68E02
Ttr (years)
30.5
23.7
24.8
27.2
39.0
39.7
41.3
a
Two times of operation for 300 days and long interval for 65 days, in real
b
Maintenance for fuel reloading of 1/6 core; short interval occurs five times for Pu-ADS and two
times for Pu+U-ADS between long intervals
c
Maintenance for accelerator and plant
216
K. Nishihara et al.
are determined as listed in Table 19.7, with specific heat and resulting transmutation half-life. Operation efficiency multiplied by cycle efficiency of the Pu-ADS is
the poorest, but the transmutation half-life is the shortest because of the high
specific heat. In the present study, a 30-day interval for fuel exchange is adopted
as a nominal case. The transmutation half-life of the Pu-ADS is 24.8 years in the
nominal case, which is applied to scenario analysis.
Another observation is that the impact of the out-core period on cycle efficiency
is significant. The out-core period is presumed considering the half-life of
242 Cm of
126.8 days. If a shorter out-core period is accomplished by corresponding design of
the reprocessing and fabrication plant, cycle efficiency and resulted transmutation
half-life can be improved. Table 19.8 shows comparison of a 3-year and 1-year
out-core period. An impact on the transmutation half-life of the Pu-ADS is a factor
of around 2, and the transmutation half-life becomes as short as 13.5 years.
Although 3 years of out-core period is applied as the nominal case, a shorter
out-core period should be pursued in future study.
Table 19.7 Assumption on maintenance schedule versus transmutation half-life for six-batch
design (equilibrium core)
ADS case
MA
Pu
Pu + U
Interval case 2 Â 65 days 15 Â 5
+ 60 Â 1
30 Â 5
+ 60 Â 1
60 Â 5
+ 60 Â 1
15 Â 4
+ 60 Â 2
30 Â 4
+ 60 Â 2
60 Â 4
+ 60 Â 2
Batch
1
6
6
6
6
6
6
Operation
(days)
600
a
50
50
50
100
100
100
Short interval (days)
b
15
30
60
15
30
60
Long interval
(days)
c
130
a
60
60
60
60
60
60
ε o (%)
82
69
59
45
77
71
63
In-core
period
(years)
2
1.19
1.40
1.81
2.01
2.22
2.63
Out-core
period
(years)
3
3
3
3
3
3
3
Ε c (%)
40
28
32
38
40
43
47
Ε o *ε c (%)
33
20
19
17
31
30
29
h (MW/tHM) 182
393
393
393
151
151
151
λtr (/years)
2.28E-02
2.93E02
2.79E02
2.55E02
1.78E02
1.75E02
1.68E02
Ttr (years)
30.5
23.7
24.8
27.2
39.0
39.7
41.3
a
Two times of operation for 300 days and long interval for 65 days, in real
b
Maintenance for fuel reloading of 1/6 core; short interval occurs five times for Pu-ADS and two
times for Pu+U-ADS between long intervals
c
Maintenance for accelerator and plant
216
K. Nishihara et al.