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    Fusion Engineering and Design 81 (2006) 415424

    Overview of design and R&D of test blankets in Japan

    Mikio Enoeda a,, Masato Akiba a, Satoru Tanaka b, Akihiko Shimizu c,Akira Hasegawa d, Satoshi Konishi e, Akihiko Kimura e,

    Akira Kohyama e, Akio Sagara f, Takeo Muroga f

    a Blanket Engineering Laboratory, Japan Atomic Energy Research Institute, Mukoyama 801-1,

    Naka-shi, Ibarak-ken 311-0193, Japanb The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japanc Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581, Japan

    d Tohoku University, Aoba 01, Aramaki, Aoba-ku, Sendai 980-8579, Japane Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan

    fNational Institute of Fusion Science, Oroshi 322-6, Toki 509-5292, Japan

    Received 13 May 2005; received in revised form 8 August 2005; accepted 8 August 2005

    Abstract

    Japan is performing design and technology developments for the purpose of module testing and contribution to the module

    development and testing under the framework of Test Blanket Working Group (TBWG) with involvements of all of Japan Atomic

    Energy Research Institute (JAERI) and universities and National Institute for Fusion Science (NIFS).

    As the primary blanket option, solid breeder test blanket modules (TBMs) with reduced activation ferritic steel structure is

    being developed and proposed to be delivered on the first day of ITER operation, mainly by JAERI. As for the advanced blanket

    options, mainly universities and NIFS have been performing R&D of key technologies and design concept development of solid

    breeder blanket test article made of SiC composite contained inside the ferritic steel box, liquid LiPb breeder blanket TBM

    cooled by helium and its dual-coolant option, liquid Li self-cooled blanket TBM and molten salt self-cooled TBM.

    In all necessary fields of the development of the primary blanket option, the element technology development phase has been

    almost completed and is now stepping further to the engineering test phase. The development of advanced test blankets is also

    showing steady progress to overcome key issues toward module testing.

    2006 Elsevier B.V. All rights reserved.

    Keywords: Test blanket module; Water-cooled solid breeder blanket; Helium-cooled solid breeder blanket; Liquid breeder

    Corresponding author. Tel.: +81 29 270 7588;

    fax: +81 29 270 7489.

    E-mail address: [email protected] (M. Enoeda).

    1. Strategy of blanket development of Japan

    The Fusion Council of Japan has established the

    long-term R&D program of the blanket development

    0920-3796/$ see front matter 2006 Elsevier B.V. All rights reserved.

    doi:10.1016/j.fusengdes.2005.08.097

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    in 1999. In the program, JAERI has been nominated

    as a leading institute of the development of solid

    breeder blankets, in collaboration with universities, as

    the primary candidate blanket [1] for a fusion powerdemonstration plant [2], while, universities and NIFS

    are assigned mainly to develop advanced blankets for

    future blanket options of the fusion power demonstra-

    tion plant and advanced power plants. As the basic

    strategy of blanket and material development toward

    fusion power demonstration plant in Japan, ITER test

    blanket module (TBM) testing, together with mate-

    rial development and qualification of irradiation per-

    formance by IFMIF, is regarded as one of the most

    important milestones, by which integrity of candidate

    blanket concepts and structures are qualified for evalu-

    ating blankets for the fusion power demonstration plant

    and advanced power plants. Based on the definition of

    the blankets of the fusion power demonstration plant

    and advanced power plants, Japan is performing R&Ds

    of all types of TBMs which have been proposed in Test

    Blanket Working Group (TBWG) [3], with involve-

    ments of all of JAERI and universities and NIFS [4],

    under the framework of TBWG. As the primary blanket

    option, solid breeder TBM with the structural material,

    reduced activation ferritic/martensitic steel (RAFM)

    [5], cooled either by water and helium are being devel-

    oped mainly by JAERI. Both of water-cooled solidbreeder TBM and He-cooled solid breeder TBM have

    been proposed to be delivered from the first day of

    ITER operation. In parallel, mainly universities and

    NIFS have been performing developments of key tech-

    nologies and design concepts of blankets of advanced

    blankets. Accordingly the TBMs or test articles of the

    advanced blanket concepts, such as, solid breeder blan-

    ket test article with the structure of silicon carbide

    composite (SiCf/SiC) [6] cooled by high temperature

    helium gas enveloped inside RAFM box, liquid LiPb

    breeder blanket TBM cooled by helium and its dual-coolant option, liquid Li self-cooled blanket TBM with

    vanadium alloy [7] and molten salt self-cooled blanket

    TBM, are now under consideration.

    With respect to the development of the primary

    candidate blanket for the fusion power demonstration

    plant, solid breeder test blankets made of RAFM are

    being developed by JAERI with cooperation of uni-

    versities, according to the stepwise development plan

    consists of elemental technology development phase,

    engineering R&D phase and ITER TBM test phase [8].

    In all essential issues of blanket development, element

    technology development has been almost completed

    and is now stepping further to the engineering R&D

    phase, in which scalable mockups of solid breeder testblanket modules will be fabricated and tested to jus-

    tify the total structure integrity and to certify the final

    fabrication specification of TBMs in the next 5 years

    [8].

    With respect to the development of the advanced

    blankets, key issues have been addressed and critical

    technologies are being developed for high temperature

    solid breeder blanket with SiCf/SiC structure, dual-

    coolant liquid LiPb breeder blanket with SiC inserts,

    liquid Li self-cooled blanket with V alloy and molten

    salt self-cooled blanket with RAFM structure by uni-

    versitiesand NIFS. The development of advanced blan-

    kets is showing steady progress toward the realization

    of the ITER TBM testing [4].

    The development of blankets in Japan is show-

    ing sound and steady progress on both of solid and

    liquid breeder blankets under coordinated domes-

    tic development strategy, for both of primary and

    advanced options. This paper presents overview of

    recent achievements in TBM designs and supporting

    R&Ds performed in Japan.

    2. Solid breeder TBMs made of RAFM

    2.1. Design of water-cooled solid breeder TBM

    Design of water-cooled solid breeder TBM has been

    performed, based on thedesign of theblanket designfor

    the fusion power demonstration plant [1]. TBM design

    conditions are seen in the reference [9]. The design

    of water-cooled solid breeder TBM has the following

    features:

    (a) First wall and side walls are fabricated by hot iso-

    static pressing (HIP) using RAFM to form built-in

    cooling channel structure.

    (b) Vertical slits were adopted to split the blanket mod-

    ule into smaller sub-modules, in less than 50 cm

    intervals, for the purpose of reducing the electro-

    magnetic force in plasma disruption events and

    increasing the endurance to internal over-pressure

    in the case of coolant ingress in the module [10].

    Sub-modules areintegratedat rear wall by welding.

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    Fig. 1. Three-dimensional view of the structure of water-cooled

    TBM.

    (c) Breeder and multiplier are packed in layered peb-

    ble beds whose partition walls are integrated with

    cooling pipes. The internal structure is designed

    accordingto thesame concept as thebreedingblan-

    ket for fusion power demonstration plant [1].

    Fig. 1 shows the schematic three-dimensional

    structure of water-cooled solid breeder TBM. The

    structure design showed sound progress to estab-

    lish detailed drawings with consideration of coolant

    route, fabrication and assembly procedures of mod-

    ules including pebble packing. Thermo-mechanical

    integrity was evaluated by FEM analysis. Thermo-

    mechanical endurance is one of the most importanttest issues. Fig. 2 shows the temperature distribution

    in the first wall of water-cooled TBM evaluated by

    two-dimensional thermo-mechanical analysis. As can

    be seen from this figure, the highest temperature of the

    structural material, 539 C, which satisfies the F82H

    design window, appeared at the most distant part of

    plasma side surface from cooling channel. By stress

    analysis, it was shown that the stress range was within

    elastic range. The highest TRESCA stress 359 MPa

    appeared at the same place as the highest tempera-

    Fig. 2. Two-dimensional temperature distribution in the cross-

    section of first wall of water-cooled TBM.

    ture appeared. This stress value was evaluated to satisfy

    3Sm value for F82H as shown in Fig. 3.

    Other important design analyses covered major

    important design issues. By neutronics analyses, neu-

    tron and gamma shielding performance of the module,

    Fig. 3. Two-dimensional stress distribution in the cross-section of

    first wall of water-cooled TBM.

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    Fig. 4. Structure of typical cross-sections of helium-cooled TBM.

    tritium production rate,time evolution of induced activ-

    ity and decay heat on nuclear performance after irra-

    diation by ITER operation [11]. By tritium control

    analysis, tritium inventory and tritium release behav-

    ior were evaluated to examine the tritium concentration

    change in the helium purge gas during the typical ITER

    operation sequence [12]. The design analyses have

    been performed based on the up-to-date achievement

    of basic investigation and R&Ds.

    2.2. Design of helium-cooled solid breeder TBM

    Helium-cooled solid breeder TBM is designed with

    the same concept as the water-cooled solid breeder

    TBM, since the helium cooling is the backup cooling

    system option to the water-cooled solid breeder blan-

    ket for the fusion power demonstration plant. Fig. 4

    shows the typical drawing of vertical and horizon-

    tal cross-sections of He-cooled solid breeder TBM.

    Detailed dimensions of cooling tube sizes and pitch

    sizes, the first wall configuration and thickness of inter-nal breeder and multiplier layers were decided taking

    into account the thermalhydraulic characteristics and

    nuclear characteristics of He gas coolant. In the case of

    helium-cooled solid breeder TBM, three sub-modules

    are integrated at the rear wall of the TBM. Internal

    structure of the sub-module has almost same box struc-

    ture and multi-layer internal structure as that of the

    water-cooled TBM. It is noted that there is a space of

    96 mm thickness in front of the back plate where neu-

    tron multiplier pebbles are not packed to lay coolant

    connecting pipes, helium purge gas connecting pipes

    and cable conduits for instrumentations. The similar

    important analyses on neutronics, thermo-mechanical

    and tritium generation of the helium-cooled solidbreeder TBM have been also performed to show the

    integrity and functional performance.

    2.3. R&D achievement of solid breeder TBMs

    To achieve the satisfactory integrity and functional

    performance of ITER TBM testing, the blanket devel-

    opment is programmed to follow stepwise phases:

    elemental technology phase, engineering R&D phase

    and demonstration test phases for basic options and

    advanced options of blankets [4].

    Essential issues of the solid breeder blanket devel-

    opment are: Out-pile R&D, In-pile R&D, Neutronics

    and Tritium Production Tests with 14 MeV Neutrons

    and Tritium Recovery System Development. Out-pile

    R&D consists of the development of blanket module

    fabrication and the development of thermo-mechanical

    and chemical compatibility design database of breed-

    ing region of the blanket. In-pile R&D consists of

    the development of irradiation technology for partial

    blanket mockups in fission reactor, the development

    of fabrication technology for breeder and multiplier

    pebbles, and irradiation tests of breeder and multi-plier pebble beds. Neutronics tests by 14 MeV neutron

    source consists of the precise evaluation of neutron-

    ics characteristics of the blanket materials and tritium

    production rate data with real blanket materials and

    mockups. The development of tritium recovery system

    consists of the development and basic research on the

    processes of blanket tritium recovery system.

    As the most important technology in the area of

    Out-pile R&D, fabrication technology of the first wall

    structure with built-in cooling channels by RAFM, the

    technology of hot isostatic pressing bonding methodhas shown remarkable progress. By using prelimi-

    nary selected HIP conditions, first wall panel mockup

    has been successfully fabricated and showed expected

    integrity under the heat load of 2.7 MW/m2 up to 5000

    cycles [13]. However, the grain coarsening and reduc-

    tion of fracture toughness of HIP joints by HIP heat

    treatment were identified. By the investigation of HIP

    condition improvement, the improved HIP heat treat-

    ment conditions were finally selected. Fig. 5 shows

    the typical microstructure of F82H after various heat

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    Fig. 5. Typical microstructure of post hip heat-treated F82H [12].

    treatment. As can be seen in Fig. 5, fine grained

    martensite structure, with ASTM grain size No. 7, was

    obtained in F82H homogenized at 1150 C followed by

    normalizing at 930 C. HIP process temperature should

    be as high as possible, however, to avoid segregation

    of-ferrite phase it should be done below 1200 C. It

    is possible that HIP process could be combined withhomogenizing. Thus, it was certified that the HIP pro-

    cess (HIP at 1150 C + PHHT at 930 C + tempering)

    could improve both the joining properties and the frac-

    ture toughness [14]. Also, the development of first

    wall armor joining to the first wall of RAFM has

    shown progress. As one of the candidate armor mate-

    rial for fusion power demonstration plant, solid state

    bonding of tungsten and F82H was studied by using

    Spark Plasma Sintering (SPS) method. According to

    the results of trial bonding and destructive observation,

    W and F82H could be joined by the solid state bonding

    without any insert material [15]. For the first wall armor

    of TBMs, beryllium is recommended. For Be armor

    joining for TBMs, the further R&D is needed based on

    the technique of HIP joining of Be and Cu alloys [16].

    In order to establish a reliable and efficient design

    of the blanket system, it is necessary to elucidate prop-erties of heat transfer in the breeder/multiplier pebble

    beds. During operations, deformation caused by dif-

    ferent thermal expansions between the pebble beds and

    structural materials will result in the deviation of effec-

    tive thermal conductivity of the beds. Therefore, the

    measurement of stressstrain characteristics and effec-

    tive thermal conductivity of breeder pebble bed was

    performed using newly developed measurement appa-

    ratus. The obtained data had a good repeatability and

    compressive strain of 1% gave increase of about 3% in

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    thermal conductivity. For the bed at all temperatures,

    increase in effective thermal conductivity due to the

    compressive deformation was found [17].

    In the area of In-pile R&D, the basic fabrica-tion technologies of tritium breeder pebbles and neu-

    tron multiplier pebbles have been established [18].

    Improvement of breeder pebble and development of

    advanced multiplier pebble [19], BeTi alloys [20],

    are showing progress. Irradiation performance of the

    developed breeder pebble bed has been evaluated to be

    feasible [21].

    With respect to the Neutronics and Tritium Produc-

    tion Tests with 14 MeV Neutrons, various neutronics

    experiments have been performed using the Fusion

    Neutronics Source (FNS) experimental facility. The

    experiments have been performed with the blanket

    mockups and the bulk beryllium assembly. The accu-

    racy of the Monte Carlo calculation with nuclear data

    libraries has been evaluated to minimize the uncertainty

    of the design value of tritium production rate (TPR)

    [22].

    With respect to the Tritium Recovery System Devel-

    opment, development of continuous tritium recovery

    system, usingmembrane permeation processes, such as

    palladium diffuser [23] and the electrochemical hydro-

    gen pump using proton conductor membrane [24].

    Also, the basic characteristics of enrichment of tritiatedwater by PSAmethod with synthetic zeolite packed bed

    [4].

    As overviewed above, fundamental researches and

    elemental technology developments have been com-

    pleted in four essential R&D areas. Now the develop-

    ment phase is stepping up to engineering R&D phase.

    By engineering R&D, it is planned to certify the final

    qualification of the module integrity, fabrication spec-

    ification of TBMs to be delivered to ITER and the

    relevancy to ITER safety.

    3. Test article concept of advanced solid

    breeder blanket made of SiC composites

    Helium-cooled solid breeder TBM applies inte-

    grated structure of three sub-modules. By using one

    of sub-modules, there is a possibility of testing dif-

    ferent concept of internal configuration of the solid

    breeder blankets. Fig. 6 shows a typical concept of test

    article of hightemperature solidbreeder/SiCf/SiC blan-

    Fig. 6. The concept of SiCf/SiC blanket unit tests in RAFM Struc-

    ture.

    ket cooled by He. One of Japanese commercial fusion

    plant uses solid breeder blanket with SiCf/SiC structure

    cooled by high temperature He. In this testing concept,

    it was proposed to insert a test article of a solid breeder

    blanket surrounded with the thermal insulation wall of

    SiCf/SiC inside the sub-module box structure made by

    RAFM. By adjusting the flow rate of He coolant to

    the test article, the operation temperature of the test

    article is raised to higher temperature than 550 C, for

    the purpose of testing the thermo-mechanical charac-

    teristics. The detailed structure including the support

    structure of the test article in the sub-module box will

    be investigated in future. In the latter 10-year period of

    ITER operation, the testing of TBM made of SiCf/SiC

    first wall may be also considered, depending on the

    development progress of materials and module fab-rication technology and the result of the test article

    testing.

    4. Liquid LiPb breeder TBM cooled by helium

    and its dual-coolant option

    Liquid LiPb blanket is one of major option of the

    TBM that attracts interests of all six parties. Helium-

    cooled lithium lead (HCLL) is intended to be tested

    to acquire maximum information for DEMO designin EU, and this TBM option is developed by Euro-

    pean leadership with all other parties involvement in

    the frame work of TBWG. However, lithium lead

    has an improved option of dual-coolant lithium lead

    (DCLL) concept for higher temperature operation. The

    original EU design of the HCLL module is made of

    RAFM vessel filled with liquid lithium lead, andcooled

    with cooling panel where high-pressure helium is cir-

    culated. With SiC insert that separates lithium lead

    from RAFM structure, lithium lead can be circulated

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    at higher temperature and flow rate because of heat

    and electrical insulation. Metal surface is protected

    from corrosion or erosion. Lithium lead works as heat

    transfer media, and provides an attractive option forhigh temperature blanket above the limit of RAFM

    with ITER/TBM. Japan showed the interest and pos-

    sibility of technical contribution on the investigation

    of SiC insert and design of DCLL option. Identi-

    fied subjects to be studied includes SiC//LiPb and

    RAFM/LiPb compatibility, evaluation of MHD effect,

    and the development of SiC insert. Kyoto University

    recently started the operation of a small LiPb loop

    as a collaboration with JAERI, and will pursue above

    technical issues to be combined with their strong tech-

    nical capability of SiC research. Through the expected

    results with international efforts, original HCLL

    will elevate the operation temperature gradually as

    DCLL.

    It is pointed out that many of the advanced reac-

    tor design including Japanese applies LiPbSiCf/SiC

    blanket to provide high grade heat above 900C,

    and this DCLL option provides practical and real-

    istic technical approach toward them starting from

    the first TBM of HCLL as a conservative design.

    Because Japan has a strategy to develop economical

    fusion reactor with single step of DEMO following

    ITER, such a multiple generations of blanket to grad-ually and steadily improve the plant performance is

    important.

    5. Self-cooled Li/V TBM

    A Design Description Document was presented

    from Russia based on Li/Be/V blanket concept, in

    which Be was used for neutron multiplying purposes

    [25]. Japanese contribution in the development of this

    type of TBM, in the framework of TBWG, is technicalsupport of the Russian TBM design. In addition to that,

    Japan is examining a Li/V test module, in which Be is

    not used [26]. The Li/V concept has some advantages

    over Li/Be/V concept such as simple blanket struc-

    ture, being free from the issues of natural resource

    limit and handling safety concerning beryllium and

    no need for periodic replacement of blanket because

    of the lifetime of Be. Elimination of Be multiplier in

    the breeding blanket will give benefits of cost reduc-

    tion and safety enhancement. This aspect is also the

    Fig. 7. Theschematic view andcross-section of theLi/V test module

    [24].

    case for solid breeder TBMs, however, it is difficult to

    eliminate Be multiplier in the solid breeder blanketswith limited thickness of radial build, without avoid-

    ing insufficient tritium breeding performance. Recent

    neutronics calculations showed enough tritium self-

    sufficiency of Li/V blanket in tokamak[26] and helical

    [27] systems.

    The primary purpose of the Li/V module test was

    defined as validation of the tritium production rate pre-

    dicted based on the neutron transport calculation. For

    this purpose the module was designed to be composed

    of sectioned thick boxes which accommodate slow Li

    flow. The schematic view and cross-section of the mod-ule is given in Fig. 7. This system enables to measure

    the tritium production rate as a function of the distance

    from the first wall. The size of the four boxes was lim-

    ited (0.027 m3) so as to satisfy the introduction limit

    of liquid lithium into the ITER test port.

    The module is covered with a B4C layer for the

    purpose of shielding thermal neutrons. Fig. 8 shows

    the neutron spectra for ITER first wall, Li/V TBM with

    B4C cover of 7.5 mm thick and V/Li full blanket [26].

    With the B4C cover, the flux of low energy neutrons

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    Fig. 8. Comparison of neutron spectra for ITER first wall, Li/V TBM

    with B4C cover of 7.5 mm thick and V/Li full blanket [24].

    decreases and the spectrum approaches that of the Li/V

    full blanket.

    The plasma-facing surfaces of the module would be

    covered with W coating. The effect of tungsten coating

    on the tritium production performance was investigated

    foraLi/VDEMOblanket [27], which showeda positive

    effect of the coating thickness on the tritium production

    rate in the case using 35% enriched 6Li. The feasibility

    of the plasma spray coating of W on V4Cr4Ti was

    demonstrated [28].

    Significant progress has been made in fabrica-tion technology of vanadium alloyed with focus

    on V4Cr4Ti alloys including fabrication of large

    V4Cr4Ti ingot, manufacturing into plates, sheets,

    wires, rods and thin tubes, laser welding and so

    on [7]. Thus manufacturing the test module with

    high quality is thought to be feasible for V4Cr4Ti

    structures.

    In Li layer (1), MHD insulator coating is necessary,

    and the test of the coating is one of the objectives of the

    layer. Current options of the coating would be (a) PVD

    coating of Er2O3 or Y2O3, (b) two-layer coating withEr2O3 (or Y2O3) covered by vanadium alloys, and (c)

    in situ coating of Er2O3 by reaction of pre-doped Er in

    Li and pre-doped O in V4Cr4Ti structural materials

    [29].

    As to the tritium recovery from Li, feasibility of

    gettering tritium by yttrium was demonstrated [30].

    Although tritium recovery technology from tritiated

    yttrium is not verified, this method seems to be feasi-

    ble to the module test where limited amount of tritium

    needs to be recovered.

    6. Molten salt TBM

    One of the candidate liquid breeder blankets applies

    molten salt, Flibe, as the self-cooling breeder [31].It has been designed for Force-Free Helical Reac-

    tor, FFHR, which is a demo-relevant helical-type D-

    T fusion reactor based on the great amount of R&D

    results obtained in the LHD project. It features the

    reduced activation ferritic steel, JLF-1, or vanadium

    alloy, V4Cr4Ti, as the structural material and Be

    pebble bed as the neutron multiplier and redox con-

    troller to reduce corrosive F radicals. To enhance the

    shielding ability, C and B4C are placed in the rear side

    region of the Flibe blanket.

    Investigation of key technologies of the Flibe blan-

    ket have been performed on the thermo-fluid study

    using Tohoku-NIFS Thermo-fluid Loop for molten

    salt (TNT Loop) built in Tohoku University (Fig. 9)

    [32], redox control technology to reduce F radi-

    cals, tritium inventory and disengaging technology

    of molten salt Flibe partly in the frame of Japan-

    US collaboration program, JUPITER-II. Flibe chem-

    istry experiments and TBM neutronics calculations

    are on going in Universities and NIFS. In parallel,

    Fig.9. Tohoku-NIFSThermo-fluid Loop for molten salt(TNT Loop)

    built in Tohoku University [30].

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    the development of structural materials and structure

    fabrication technology are being performed. Japanese

    universities and NIFS are cooperating to support the

    activity related to molten salt TBM concept in theframeworks of TBWG and JUPITER-II program. The

    technology of thermohydraulics of Flibe can be cov-

    ered by the scale of TNT Loop. The further R&D

    achievements are expected to be obtained by TNT

    Loop.

    7. Conclusions

    (1) Japan is performing design and technology devel-

    opmentof breeding blanketswith the aim of testing

    TBMs and contributing to all types of TBMs under

    the framework of TBWG with involvements of all

    of JAERI, universities and NIFS.

    (2) For the primary blanket option, development

    of solid breeder blankets has been pursued.

    Elemental technology development has been

    almost completed on all of necessary technolo-

    gies, fabrication of module structure, irradia-

    tion performance tests, fabrication technology

    development for breeder and multiplier peb-

    bles, neutronics tests by 14 MeV neutron source

    and tritium recovery system for blanket tritiumpurge gas. Now the engineering R&D phase

    is starting for the purpose of determination of

    the fabrication specification of TBMs, in four

    major R&D areas, Out-pile R&D, In-pile R&D,

    Neutronics and Tritium Production Tests with

    14 MeV Neutrons and Tritium Recovery System

    Development.

    (3) For advanced options of blankets, key issues have

    been addressed and the development of criti-

    cal technologies are showing remarkable progress

    for high temperature solid breeder blanket withSiCf/SiC structure, liquid LiPb breeder blanket

    with SiC inserts as its dual-coolant option, liquid

    Li self-cooled blanket with V alloy and molten salt

    self-cooled blanket with RAFM structure by uni-

    versities and NIFS.

    (4) For Li self-cooled blanket development, new con-

    cept of TBM without Be multiplier was proposed.

    Fabrication technology of vanadium alloy in large

    scale has been demonstrated. Also, development

    of insulation coating has shown progress.

    (5) For molten salt self-blanket development, thermo

    hydraulics technology of Flibe has shown remark-

    able progress by using TNT Loop.

    References

    [1] M. Enoeda, Y. Kosaku, T. Hatano, T. Kuroda, N. Miki, T.

    Honma, et al., Design and technology development of solid

    breeder blanket cooled by supercritical water in Japan, Nucl.

    Fusion 43-12 (2003) 18371844.

    [2] S.Konishi, S. Nishio, K. Tobita,The Demo designteam, DEMO

    plant design beyond ITER, Fusion Eng. Des. 6364 (2002)

    1117.

    [3] L. Giancarli, V. Chuyanov, M. Abdou, M. Akiba, B.G. Hong,

    R. Lasser, et al., Breeding blanket modules testing in ITER: an

    international program on the way to DEMO, Fusion Eng. Des.

    81 (2006) 393405.[4] M. Enoeda, M. Akiba, S. Tanaka, A. Shimizu, A. Hasegawa,

    S. Konishi, et al., Plan and strategy for ITER blanket testing in

    Japan, Fusion Sci. Technol. 47-4 (2005) 10231030.

    [5] S. Jitsukawa, M. Tamura, B. van der Schaaf, R.L. Klueh,

    A. Alamo, C. Petersen, et al., Development of an extensive

    database of mechanical and physical properties for reduced-

    activation martensitic steel F82H, J. Nucl. Mater. 307311

    (2002) 179186.

    [6] B. Riccardi, L. Giancarli, A. Hasegawa, Y. Katoh, A. Kohyama,

    R.H. Jones, et al., Issues and advances in SiC f/SiC composites

    developmentfor fusion reactors,J. Nucl. Mater.329333 (2004)

    5665.

    [7] T. Muroga, T. Nagasaka,K. Abe,V.M. Chernov, H. Matsui, D.L.

    Smith, et al., Vanadium alloysoverview and recent results, J.Nucl. Mater. 307311 (2002) 547.

    [8] M. Enoeda, T. Hatano, K. Tsuchiya,K. Ochiai, Y. Kawamura, K.

    Hayashi, et al., Development of solid breeder blanket at JAERI,

    Fusion Sci. Technol. 47-4 (2005) 10601067.

    [9] V. Chuyanov, ITER International Team, Interface of blanket

    testing and ITER design, Fusion Sci. Technol. 47-3 (2005)

    469474.

    [10] Y. Nomoto, S. Suzuki, K. Ezato, T. Hirose, D. Tsuru, H. Tani-

    gawa, et al., Design of solid breeder test blanket modules in

    Japan, in press.

    [11] D.Tsuru, T. Hatano, M.Enoeda,T.Kuroda,N. Miki,T.Homma,

    et al., Proceedings of the 11th International Workshop on

    Ceramic Breeder Blanket Interactions, December 1517, 2003,Tokyo, Japan, JAERI-Conf 2004-012, 2004, pp. 3539.

    [12] T. Kinjyo, M. Nishikawa, T. Tanifuji, M. Enoeda, Introduction

    of tritium transfer step at surface layer of breeder grain for mod-

    eling of tritium release behavior from solid breeder materials,

    Fusion Eng. Des. 81 (2006) 573577.

    [13] T. Hatano, T. Kuroda, M. Enoeda, S. Suzuki, K. Yokoyama,

    et al., High heat flux test of a HIP-bonded first wall panel of

    reduced activation ferritic steel F-82H, J. Nucl. Mater. 283287

    (2000) 685.

    [14] T. Hirose, K. Shiba, T. Sawai, S. Jitsukawa, M. Akiba, Effects

    of heat treatment process for blanket fabrication on mechanical

    properties of F82H, J. Nucl. Mater. 329333 (2004) 324327.

  • 7/27/2019 Overview of Design and R&D of Test Blankets in Japan

    10/10

    424 M. Enoeda et al. / Fusion Engineering and Design 81 (2006) 415424

    [15] T. Hirose, S. Suzuki, K. Shiba, T. Sawai, S. Jitsukawa, M. Akiba,

    Proceedings of the 11th International Workshop on Ceramic

    Breeder Blanket Interactions, December 1517, 2003, Tokyo,

    Japan, JAERI-Conf 2004-012, 2004, pp. 203208.

    [16] T. Hatano, T. Kuroda, V. Barabash, M. Enoeda, Developmentof Be/DSCu HIP bonding and thermo-mechanical evaluation,

    J. Nucl. Mater. 307311 (2002) 15371541.

    [17] H. Tanigawa, T. Hatano, M. Enoeda, M. Akiba, Effective ther-

    mal conductivity of a compressed Li2TiO3 pebble bed, in:

    Proceedings of 23rd SOFT in Venice, Italy, 2004. Fusion Eng.

    Des., in press.

    [18] H. Kawamura, E. Ishitsuka, K. Tsuchiya, M. Nakamichi, M.

    Uchida, H. Yamada, et al., Development of advanced blanket

    materials for solid breeder blanket of fusion reactor, FT/P1-

    09, Fusion Energy 2002 (Proceedings of the 19th International

    Conference, Lyon, 2002) (Vienna: IAEA) CD-ROM file FT/P1-

    9 and http://www.iaea.org/programmes/ripc/physics/fec2002/

    html/fec2002.htm.

    [19] K. Tsuchiya, H. Kawamura, S. Tanaka, Evaluation of contact

    strength of Li2TiO3 pebbles with different diameters, Fusion

    Eng. Des. 81 (2006) 10671071.

    [20] T. Hoshino, M. Yasumoto,K. Tsuchiya,A. Suzuki, K. Tsuchiya,

    K. Hayashi, et al., Vapor species evolved from Li2TiO3 heated

    at high temperature under various conditions, Fusion Eng. Des.

    81 (2006) 555559.

    [21] K. Tsuchiya, A. Kikukawa, T. Hoshino, M. Nakamichi, H.

    Yamada, D. Yamaki, et al., In situ tritium recovery behavior

    fromLi2TiO3 pebble bed underneutronpulse operation, J. Nucl.

    Mater. 329333 (2004) 12481251.

    [22] S. Sato, Y. Verzilov, K. Ochiai, M. Nakao, M. Wada, N. Kub-

    ota, et al., Progress in the blanket neutronics experiments at

    JAERI/FNS, Fusion Eng. Des. 81 (2006) 11851195.

    [23] Y. Kawamura, M. Enoeda, T. Yamanishi, M. Nishi, Feasibility

    study on the blanket tritium recovery system using the palla-

    dium membrane diffuser, Fusion Eng. Des. 81 (2006) 801

    814.

    [24] Y. Kawamura, S. Konishi, M. Nishi, Extraction of hydrogenfrom water vapor by hydrogen pump using ceramic protonic

    conductor, Fusion Sci. Technol. 45-1 (2004) 3340.

    [25] I.R. Kirillov, G.E.Shatalov,Y.U.S.Strebkov,the RF TBM team,

    RF TBMs for ITER tests, Fusion Eng. Des. 81 (2006) 425432.

    [26] T. Muroga, T. Tanaka, Neutronics investigation into

    lithium/vanadium test blanket modules, Fusion Sci. Technol.

    47-3 (2005) 540543.

    [27] T. Tanaka, T. Muroga, A. Sagara, Tritium self-sufficiency and

    neutron shielding performance of self-cooled liquid blanket,

    Fusion Sci. Technol. 47-3 (2005) 530534.

    [28] T. Nagasaka,T. Muroga, N. Noda, M. Kawamura, H. Ise, Tung-

    sten coating on low activation vanadium alloy by plasma spray

    process, Fusion Sci. Technol. 47-4 (2005) 876880.

    [29] B.A. Pint, P.F. Tortorelli, A. Jankowski, J. Hayes, T. Muroga, A.

    Suzuki, et al.,Recent progress in the development of electrically

    insulating coating for a liquid lithium blanket, J. Nucl. Mater.

    329333 (2004) 119124.

    [30] M. Kinoshita, S. Fukada, N. Yamashita, T. Muroga, M.

    Nishikawa, Experimental study of tritium recovery from liq-

    uid lithium by yttrium, Fusion Eng. Des. 81 (2006) 567571.

    [31] A. Sagara, T. Tanaka, T. Muroga, H. Hashizume, T. Kunugi,

    S. Fukada, et al., Innovative liquid blanket design activities in

    Japan, Fusion Sci. Technol. 47-3 (2005) 524529.

    [32] S. Chiba,M. Omae, K. Yuki, H. Hashizume, S. Toda, A. Sagara,

    et al., Experimental research on heat transfer enhancement for

    high Prandtl-number fluid, Fusion Sci. Technol. 47-3 (2005)

    569573.

    http://www.iaea.org/programmes/ripc/physics/fec2002/html/fec2002.htmhttp://www.iaea.org/programmes/ripc/physics/fec2002/html/fec2002.htmhttp://www.iaea.org/programmes/ripc/physics/fec2002/html/fec2002.htm