Super-DIREX:Supercritical fluid
Direct Extraction

Mitsubishi Activities for Nuclear
Fuel Cycle Development

TBP Nitric
Acid Complex
Conditioner

Stripping Column

Direct Extraction Column

Solvent Washing
Equipment
CO2CO2
Liquefier Stripping Solution Purifier(Nitric Acid)
Spent
NuclearFuel

HIROSHI SAGAWA*1

YUKIHIDE MORI*1

1

TATSUHIRO YOSHIZU*1

KAZUHIKO KURODA*L

SpentSolvent
Extraction Sump Tank
Device Unit

Extraction
TBP Nitric
Residue
Acid Complex(FP)
Regulating Tank
Vitrification
CanisterU-Pu Solution Tank

In October 2005, the basic targets under the Framework for Nuclear Energy Policy1 of this country were approved in a Cabinet
meeting and the nation is proceeding with the steadfast promotion of the light water reactor fuel cycle and the research anddevelopment of the fast breeder reactor fuel cycle (FBR fuel cycle)2 aiming at full production around 2050. MHI has contributed
greatly to the design, construction and commissioning of facilities related to the light water reactor fuel cycle including the Rokkasho
Reprocessing Plant, and is involved proactively in the R&D of the FBR fuel cycle, as typified by its initiative role in the promotion ofthe basic design of the Recycle Equipment Test Facility proposed by the Independent Administrative Institution Japan Atomic Energy
Agency (JAEA), thus contributing to the stability of energy supplies in this country as well as a reduction of the environmental
burden.

of radioactive waste3 are made possible by virtue of this cyclicsystem.
To be more specific:
a. Although uranium will not last for 100 years from now if
continuously used at the current pace, the utilization ofplutonium by means of FBRs could dramatically improvethe utilization efficiency of uranium resources, thereby
making a significant contribution to the stable supply ofenergy.
b. If spent nuclear fuels are recycled, the volume of high-level
radioactive waste could be reduced to approximately 1/3
compared to direct disposal, thereby contributing to the
reduction of the environmental burden.

1. What is the nuclear fuel cycle?
The nuclear fuel cycle refers to the reuse of the remaining
non-fissioned uranium and newly produced plutonium after
extracting them from the spent nuclear fuels released from
nuclear power plants by means of reprocessing processes(Fig. 1). 2 Both the effective use of uranium and the reduction

NaturalUranium Ore

Uranium FuelUraniumFuel
Mine Manufacturing
Process(enrichment, etc.)

NuclearPower Plants(LWRs)

Nuclear Power Plants(FBR)

2. MHI’s activities for promoting the nuclear fuel cycle

Uranium-Plutonium
Mixed Fuel

2.1 Activities toward establishing the LWR fuel cycle(1) Rokkasho Reprocessing Plant
Japan Nuclear Fuel Ltd. is currently implementing
active tests using spent LWR fuels aiming at completing
construction in 2008. MHI has participated in the projectfrom the basic design phase and has taken charge of thedesign, manufacture and commissioning of the headend facilities for shearing and disssolution of the fuelassemblies under license from France as well as analytic
facilities for analyzing the samples transferred from theoverall plant.
(2) Plutonium utilization in LWRs
Plutonium ut ilizat ion in LW Rs is mak ing steadyprogress as epitomized by the prior understanding andapproval gained from local people in the Genkai Power

Plutonium Utilization in LWRs
FBR
Cycle

Present MOX Fuel Plant

Fuel Plantfor FBRs

U-Pu
Reprocessing
Plant
High-Level
Radio-active Waste

FutureFBR Spent FuelInterimStorage
Facility

Spent Nuclear FuelMOX Fuel
LWR
Cycle

U-Pu

High-Level
Reprocessing
Radio-activePlant
Waste Ultimate- for FBRs
Disposal Facility

Fig. 1 Nuclear fuel cycle2

Mitsubishi Heavy Industries, Ltd.
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2010

Feasibility Studyof Production
Fast Reactor
Cycle Systems (FS)(1999-2006)
Clarification of theconcept candidate
for production
Check& Review
Experimental
Joyo FR

Review by the government/basic policy

20052015

Fast Reactor Cycle Technology Development Project (FaCT)
Selection of innovativetechnology (2010)

Confirmation of engineering
feasibility (2015)

Elemental R&D of innovative technology
Conceptual design of commercial& demonstration FR cycle facilities(JFY)

Around 2050

Introduction of FBR cycle
on a commercial basis
Demonstration
Validationof economy and reliabilityof technology on anengineering level
Around 2025
Operation of demonstration reactor (2025 -)Design, construction and operationof fuel cycle demonstration facilities

Commercial
FBR cycle
Around 2015

Basic design and constructionof demonstration reactor

Conceptual design and R&D programfor demonstration reactor and fuel cycle demonstration
facilities and commercial facilities

PrototypeMonju FBR
Demonstrate reliability as an operation power plant
R&Dat Monju Establish sodium handling technology
Cooperation with domestic organizations

Field for demonstration of innovative technology
such as irradiation application at a real plant

International cooperation (GNEP, GEN-IV, INPRO, etc.)

Fig. 2 FBR Fuel Cycle Technology Development Project3

Plant of Kyushu Electric Power Co., Inc. and the Ikata
Power Plant of Shikoku Electric Power Co., Inc. MHI iscommitted to promoting plutonium utilization in LWRs
over a wide range of fields related to mixed oxide fuels(MOX fuels) such as design, safety evaluation, reactor
core design, impact assessment of plant equipment,
transpor t- container design and conditioning of f uelfabrication.

(2) Participation in the design of Recycle Equipment Test Facility
MHI is proactively involved in the development ofmachines and equipment for practical use, while taking
an initiative role in the basic design of the Recycle
Equipment Test Facility implemented in JFY 2006 and2007.
(3) Development of supercritical direct-extraction method(Super - DIREX method)M H I h a s b e en en g a ge d i n t he develop ment oftechnology to extract uranium and plutonium directlyfrom spent nuclear fuels by applying supercritical fluid
since 1997. In May 2004 it succeeded in the world’s
first direct extraction of uranium and plutonium fromfragments of MOX fuel pellets in cooperation with theformer Japan Nuclear Cycle Development Institute and

2.2 Activities toward the early production of the FBR
fuel cycle(1) Conceptual road map toward a commercial FBRFBR cycle technology is an energy technology forthe effective utilization of limited uranium resourceswhich will reduce the environmental burden to support
a sustainable society, and accordingly its development
w ill need large - scale and long-term suppor t by thenation and is hence ranked as an Essential National
Technolog y. 4 M E X T decided t he combi nat ion of a
sodium-cooled fast breeder reactor, advanced aqueous
reprocessing and simplified pellet fuel fabrication5 as themain concepts to be developed intensively in the future
based on the outcome of the JFY 2006 Feasibility Studyof Commercialized Fast Reactor Cycle Systems (FS)Phase II. 5 In response, JAEA plans 3 to take a step-by-step
approach toward promoting the FBR fuel cycle throughinnovative technology, systematization of the preparations
for recycling equipment radioactive tests and an overview
of the results of R&D on the transition from the LWR fuelcycle to the FBR fuel cycle until 2010. It also proposes
conceptual design and R&D programs from 2015 onward
for commercial and demonstrative facilities in 2015, forcheck and review by the state (Fig. 2).

Fig. 3 Outward Appearance of Direct Extraction Test Equipment7Former JNC/Test equipment installed inside the CPF glove box

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54

Nagoya University (Fig. 3).6
With this technology, the simplification of the mainprocesses in aqueous reprocessing was attained, and thereduction of high-level radioactive liquid waste was madepossible owing to minimizing the quantity of nitric acidrequired for extraction, thus the possibility of improved
economic efficiency of reprocessing facilities increased.

References
1. Japan Atomic Energy Commission, “Framework for Nuclear
Energy Policy” (2005)
2. Nuclear Energ y Subcommit tee of the Elect r icit y Indust r y
Com m it tee, A dv isor y Com m it tee on Energ y a nd Nat ura lResources, “Nuclear Energy National Plan” (2006)
3. Japan Atomic Energy Agency, “Collection of FaC T Seminar
Materials” (2007)
4. Council for Science and Technology Policy “Promotion Strategies
Classified by Field” (2006)
5. Japan Atomic Energy Agency, Japan Atomic Power Company, Ltd.,“Phase II Final Report of Feasibility Study on Commercialized
Fast Breeder Reactor Cycle Systems” (2006)
6. Tomozo Koyama, Yukihide Mori, et al., “Study of Direct Extraction ofU, Pu from Spent Nuclear Fuels by Super-DIREX Reprocessing
Method”
7. Technical Development Relating to the Direct Extraction of U, Pu
from Spent Nuclear Fuels by Super-DIREX Reprocessing Method(19) - Summary of the Achievements -, Atomic Energy Society ofJapan, Annual Meeting in Spring 2005 (2005)

3. Conclusion
MHI recognizes the importance of the nuclear fuel cycle
which is a national project and has been proactively involvedin that program from the initial stage of the development. In
response to the recent Cabinet approval of the Framework
for Nuclear Energy Policy,1 the government, JAEA, electricpower utilities and plant makers are requested to promoteincreased development through mutual coordination andcombined efforts, and MHI also is prepared to work actively
to contribute its share to this important project.

Hiroshi Sagawa

Yukihide Mori

Kazuhiko Kuroda

Tatsuhiro Yoshizu

Mitsubishi Heavy Industries, Ltd.
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