26.08.2015   Study on Neutron Spectrum of Pulsed Neutron Reactor

Result of LWR-OT

Figure 19.5 illustrates a result of the LWR-OT scenario where time evolution of electricity generation, Pu inventory, and MA inventory are shown. The peak of 50 GWe appears in 2010 and decreases because of the Fukushima accident and closure after 40-year operations. All LWRs will be shut down in 2055. The Rokkasho reprocessing plant (RRP) will not be operated, but 7,100 tHM spent fuel has been reprocessed, mainly overseas. The year of reprocessing is not clear

Table 19.9 Scenarios

Scenario

Pu

MA

Conventional

LWR-OT (once-through)

Waste

Waste

LWR-PuT

LWR

Waste

Transmutation

FR (Pu+MA15 %)

FR

FR

ADS (TRU)

ADS

ADS

FR (Pu+MA5 %)+ADS (TRU)

Mainly, FR

Mainly, ADS

Table 19.10 Characteristics of transmutation systems

FR

Pu-ADS

MA-ADS

Power (thermal/electric)

GWe

1.6/0.6

0.8/0.264

Pu ratio (in/out)

%

37.5/45

~100

~35

MA/HM ratio

%

<5

—

~65

Batch number

4

6

1

Operation period

Day

183

50

600

Operation efficiency

%

84 %

59 %

82 %

In-core period

Year

2.39

1.40

2.00

Out-core period

Year

3.00

3.00

3.00

Cycle efficiency

%

44 %

32 %

40 %

Burn-up

GWd/tHM

58.56

120

108

Specific heat

MW/tHM

80

400

180

^tr

/year

1.13E-02

2.84E-02

2.25E-02

Ttr

Years

61.3

24.4

30.9

Initial inventorya

t/unit

45.1

6.3

11.1

aInitial inventory involves fuel in core and in fuel cycle (cooling, reprocessing, and fabrication)

but assumed to be in the 1990s. A small amount of MOX fuel from this reprocessing will be utilized in LWRs.

Pu inventory mainly exists in UO2-SF. “Pu” in the figure is not “separated” Pu, but Pu in MOX fresh fuel in this scenario. The total of plutonium is 350 t that is gradually disposed of to a repository from 2043 until 2105. The trend of MA inventory is almost the same, but it continues to increase after 2040 because 241Pu becomes 241Am with a half-life of 14.35 years.