Fukushima Fuels and Materials Department

FBR (Fast Breeder Reactor) is a fast neutron reactor designedto breed fuels by producing fissile materials.

FBR usually uses a uranium and plutonium mixed oxide(MOX) fuel core. The plutonium can be supplied from spentfuels of light-water reactor (LWR) and FBR by reprocessing.Therefore, the FBR is the key technology for Japan from theview of energy security and effective utilization of resources.

JAEA promotes R＆Ds of FBR cycle system, i.e. FBR plant,

fuels and materials for FBR, reprocessing and disposal of highlevel waste.

Outline of FBR

R＆D activity in FMD

The experimental fast reactor “JOYO”

AGF(Alpha-Gamma Facility)

Core part in JOYO

MMF(Materials Monitoring Facility)

FMF(Fuels Monitoring Facility)

PFRF(Plutonium Fuel Research Facility)

R＆Ds of the high-performance fuels (nitride fuels etc…)

Design, manufacturing and inspection of fuel pins for irradiation test in JOYO and JMTR

PIEs of fuel assemblies and fuel pins and analysis of their irradiation behavior

Material sampling from fuel assemblies for PIEs in AGF and MMF

The experimental fast reactor “JOYO” was

constructed to achieve technical experience for

future FBR. In addition, irradiation test of advanced

fuels and materials have been carried out.

Higher burn-up of nuclear fuels is required for FBR with an high economical efficiency. Since coreconditions in FBR such as temperature and neutron fluencies are much more severe than in LWR, thefuels and materials during irradiation up to high burn-up should be newly investigated.

To satisfy these needs, FMD has investigated the irradiation behaviors of fuels and materials for FBRby the various post-irradiation examinations (PIEs) of fuels and materials irradiated in experimentalreactors (JOYO, JMTR and others). FMD has achieved a lot of reliable data which can be reflected tothe nuclear design of FBR.

Based on these technology and experiences, FMD also promotes R＆Ds of the high-performancefuels and materials.

FMD has four hot laboratories ; FMF, AGF, MMF and PFRF.

R＆Ds of nuclear fuels

Fuel pellet

Fuel pin

Cladding materials

Fuel assembly

R＆D of nuclear fuels and materials for FBR in FMD*

R＆Ds of the high-performance fuels (oxide fuels)

PIEs of nuclear fuels and analysis of their irradiation behavior

※FMD：Fukushima Fuels and Materials Department

PIEs of core/structural materials and analysis of their irradiation behavior

R＆Ds of the high-performance materials

R＆Ds of materials

R＆Ds of fuel assemblies

R＆Ds of fuel pins

Outcomes from PIEs and R&D activities in FMD

Both non-destructive and

destructive tests for fuel assembly

irradiated in experimental fast

reactor, JOYO, are carried out to

evaluate the effect of irradiation.

Fuels and materials irradiated as

a fuel assembly in JOYO are

transferred for the intermediate

inspection. Irradiated specimens are

re-assembled and reloaded into

JOYO after the inspection, making it

possible to achieve higher burn-up

of fuels and obtain irradiation data

of materials at higher dose.

Post Irradiation Examination of Fuel Assembly

Cross-section image of fuel assembly taken by X-ray CT

Fuel pin

Wrapper tube

Manipulator

Irradiated

specimen

s

Assembly

Collimator

X-ray detector

Protecting tube

Absorber pinsB4C pellets

PIE of control rod is carried out for

developing long-lived control rod.

Elements of the control rod are

composed of absorber pins, B4C

pellets, and outer protecting tube.

The X –ray CT images are utilized to

understand deformation behavior of

these elements of control rod due to

irradiation.

In addition, density measurements

and microstructural observations of

B4C pellets are performed to

evaluate the irradiation behavior of

control rod.

Post Irradiation Examination of Control rod

X-ray CT image of control rod

Microstructureof B4C pellet

25nm

X-ray source

X-ray computed

tomography (X-ray CT)

provides cross-sectional

image of a fuel assembly,

configuration of fuel pins,

and also distribution of

central void formed in the

irradiated fuel pellet.

The X –ray CT images are

obtained non-destructively

and utilized for evaluating

irradiation behavior of fuel

assembly.

1nm = 1 x 10-9m

Development of MAs-containing MOX fuel

MAs recovered from spent nuclear fuels are of

special concern because of their lasting radiotoxicity.

Therefore, recovery and recycling of MAs in FBR

should be key technology for the reduction of

environmental burden and a sustainable energy

supply for the future.

Appearances and ceramograph

image of Am-containing MOX fuels

Microstructure of

Am-containing

Inert matrix fuel

Thermal ionization mass

spectroscopy (TIMS) partially

installed in glove box

The fuel burn-ups of MOX fuels have been determined with

a high degree of accuracy by the measurements of uranium,

plutonium and Neodymium isotopes in irradiated fuels. The

transmutation behaviors of minor actinides (MAs: Np, Am and

Cm) have been also experimentally investigated.

Separated isotope solution

from irradiated nuclear fuel

solutions

PIEs of nuclear fuel

Melting temperature and source term of irradiated MOX

fuels have been investigated for the evaluation of fuel

behaviors under normal and accident conditions. The phase

relation, elements distribution and microstructure changes of

irradiated MOX fuels have been also investigated to

understand the mechanisms of the irradiation behavior.

Elemental distribution of Pu,

Am in irradiated MOX fuel

High frequency induction

furnace in shielded cell

Microstructure of

irradiated MOX fuel

Outcomes from PIEs and R&D activities in FMD

PIEs of uranium-plutonium mixed oxides (MOX) fuels for a

FBR are carried out, and their irradiation behavior are

evaluated for a fuel design.

The R&D of MAs-containing fuels, i.e. Am-

containing MOX fuel and inert matrix fuel such as

Cercer and Cermet fuels, have been carried out.

The MAs-containing fuels with good characteristics,

i.e. having no defects, a high density and a

homogeneity, were successfully fabricated by a

remote handling system.

Based on a concept of grain-boundary

engineering, the R&D of high performance

cladding materials are carried out for the

purposes of expanding its application areas

and improving properties of the existing core

structural materials.

Developmental austenitic steels with

extremely high density of coincidence site

lattice (CSL) boundary are successfully

fabricated by the modification of former

thermo-mechanical processing.

Influence of fast neutron irradiation and irradiation

environment on mechanical properties/microstructure

of core structural materials developed for Japan

sodium-cooled fast reactor (JSFR) are evaluated.

Tensile properties for cladding tube specimens

irradiated at systematic irradiation condition are

investigated using tensile test machine, and irradiation

data of cladding tube materials have been

accumulated for the core materials design of JSFR.

In addition direct observation of lattice image of

precipitate with the size of a few nanometer is

conducted using field emission transmission electron

microscope (FE-TEM) and utilized for the evaluation of

phase stability under irradiation.

3nm

0.278nm

0.275nm

72°

(222)

Post Irradiation Examination of core materials

Development of High Performance fuel cladding by optimizinggrain-boundary-character distribution (GBCD)

FE-TEM (JEM 2010F) equipped with energy dispersive X-ray spectrum (EDS)

High resolution image of oxide dispersoid

EBSPs* of cladding material before and after

optimizing GBCD; Black and gray lines indicate

random and CSL boundaries, respectively.

Tensile test for tube specimen

After TestBefore Test

Outcomes from PIEs and R&D activities in FMD

*EBSP : Electron Back Scattering Pattern

Glove box

Hot cell

A glove box has a highly air-tightness.Examinations of low-level radioactivefuels and materials can be carried outwith relative ease in a glove box throughthe acrylic window.

Equipments in hot laboratory

Examinations by glove box

Examinations by remote access

A cask is a shield-flask. FMD has thevarious cask specified based on weight,size and radioactive levels of specimens.Irradiated fuels and materials can besafely transported between the facilitiesby using the appropriate cask.

Concrete, iron and lead have the

shielding capability for radioactivity.

※

Transportation of irradiated specimens by using a cask

cask

Shield wall

The thick wall made of

concretes, iron or lead

which prevents

operators from exposure

Shielding window

The window made of

glass contained lead to

monitor the inside of cell

Master slave manipulator (MS)

Robotic arms to handle

specimens in the cell

Power manipulator

Robotic arms capable

to lift heavy objects

Overhead crane

Crane to deliver the

heavy objects

Testing device

The devices designed from

the viewpoint of resistance

to irradiation and remote

handling performance

The shield-cell is made of heavy concrete, iron or lead. It can keep radioactive materialsinside by means of controlling the inside atmosphere on negative-pressure. Since FMD has alot of the shield-cell, irradiated fuels and materials which have high radioactivity can behandled in it. The examinations and machine operations are carried out using remotehandling equipments such as power/master slave manipulators and overhead cranes.

Cask

Research facilities of fuels and materials

department (FMD) have been utilized by internal

/external researchers and engineers.

In Plutonium Fuel Research Facility (PFRF), one

of FMD facilities, R&D has been progressing on a

nitride fuel and a metallic fuel for fast reactor

application. In addition, fundamental studies on

transmutation target for long-lives minor actinides

and on pyrochemical reprocessing using molten

salt have been carried out.

Although nitride fuel and a metallic fuel have

several advantages compared with oxide fuel in

terms of elemental density of heavy metal and

thermal conductivity, they easily react with oxygen

and moisture.

In PFRF, fabrication and preparation of fuels are

carried out in glove boxes with high-purity argon

(Ar) gas atmosphere. Advanced fuels with

fascinating properties and experimental samples

for physical property measurement can be

manufactured. In addition, microstructure

observations at high magnification and elemental

analyses of fuels have been performed to

determine the chemical morphology by Scanning

Electron Microscope（SEM）connected with a

glove box .

Facility sharing/Human resource development

TIG welder for fabrication of fuel pin

High-purity Ar gas glove boxes

FMD have received visiting researchers

from various oversea institutes (including

graduate students of domestic university) in

the frameworks of joint research program.

These frameworks offer active supports

for human resources development in the

research field of nuclear energy. Experimental scenery with visiting researchers

Joint Research with visiting researcher

SEM connected with a glove box

Outcomes from facility sharing with internal/external users

Time-line of FMD

Japan Atomic Energy Agency

Fukushima Fuels and Materials Department、O-arai Research and Development Center

South gate

PFRF

Adress ； 〒311-1393

4002, Narita-cho, O-arai-machi,

Higash-ibaraki-gun, Ibaraki

TEL ； (029)267-4141

URL ； http://www.jaea.go.jp

AGFFMF

MMF

JOYO

In 2006・Start PIEs of fuels (Am-1 fuels)

irradiated at MK-ⅢCore of JOYO

In 1969・Completion of the AGF

In 1971 ・Start hot testing in the AGF

In 1972 ・Start PIEs of irradiated fuels from

Rapsodie

In 1977・Completion of the additional AGF

In 1979・Start PIEs of irradiated fuels from

Rapsodie, a French FBR

In 1980・Start hot testing in the additional

AGF

In 1983・Start PIEs of fuels irradiated at

MK-ⅡCore of JOYO

In 1994・Start installation of the remote

fuel fabrication equipments

In 1972・Completion of the MMF

In 1973 ・Start hot testing in the MMF

In 1980 ・Received irradiated specimen

from Phenix, a French FBR

・Start PIEs of materials irradiated

at MK-ⅡCore of JOYO

In 1982・ Completion of the additional MMF

In 1984・Start hot testing in the MMF-2

・Start PIEs of materials irradiated

at MK-ⅡCore of JOYO

In 1987・Received the first specimen from

the ATR confirmation test

In 2002・Success of high-resolution imaging

of irradiated materials by the Field

Emission Transmission Electron

Microscope (FE-TEM)

In 2005・Start PIEs of materials irradiated by

CMIR rig at MK-ⅢCore of JOYO

Establishment of Japan Atomic Energy Agency in 2005

In 1974・Completion of the PFRF

In 1977 ・Start hot testing in the PFRF

・Start use of plutonium

In 1982 ・Manufacturing carbide fuel pins

mixed U-Pu for irradiation test in

JMTR

In 1989 ・Manufacturing nitride fuel pins

mixed U-Pu for irradiation test in

JMTR

In 1993・Manufacturing nitride fuel pins

mixed U-Pu for irradiation test in

JOYO

In 2006・Assembling of fuel assemblies contained MA

(reload into MK-ⅢCore)

In 1972・Completion of the FMF

In 1978・Start of hot testing in the FMF

・Start PIEs of fuel assemblies

irradiated at MK-ⅠCore of JOYO

In 1983・Start PIEs of fuel assemblies

irradiated at MK-ⅡCore of JOYO

In 1993・Completion of the additional FMF

In 1999・Start hot testing in the additional

FMF

・Success of imaging of irradiatedfuel assemblies by X-ray CT

testing

In 2004・Start PIEs of fuel assemblies

irradiated at MK-ⅢCore of JOYO

Plutonium Fuel Research Facility

燃料研究棟

In 1998・Establishment of the method of

molten salt electrolysis of Pu nitride

and Np nitride

In 2000・Success of simultaneous recovery

of U and Pu at the liquid Cd

electrode by molten salt electrolysis

In 2010・Completion of U-Pu-Zn alloy fuel

pins used to irradiation test in

JOYO

In 1999・Start fabrication tests of Am-MOX fuels by the remote handling

system

In 2003・Establishment of fabrication process of Am-MOX fuels by the

remote handling system