Proceedings Proceedings Proceedings ofof the the Fifth Fifth In Internationa阻 mation a1 l SymposiumSymposiu m ono n AdvAdvance岨 ced. d Nuclear Nuclear Energy Energy RResearc曲目rch h -NEUTRONS—NEUTRON S ASA S MICROSCOPICMICROSCOPI C PROBES — 1-161-1 6

NEUTRONNEUTRO N RADIOGRAPHYRADIOGRAPHY ・- STATUSSTATUS ANDAN D INTERNATIONALINTERNATIONA L PROSPECTSPROSPECT S

JohnJoh n P. P. BARTONBARTO N

NRENR E INCINC. . 1422142 2 VueVu e DuD u BayBa y Court ,， SanSa n Diego ，, CAC A 92109 ，, USUSA A

ABSTRACTABSTRAC T

NeutronNeutro n radiography radiography (or (or radiology) radiology) is is a diverse diverse 罰fieleld d that that usesuse s neutronsneutrons ofof various various energies ,， subthermal ,， thermal thermal ，, epithermal epitherma l or or fast fas t in in either either steady steady state state or or pulsed pulsed modemod e to to to examineexamin e objects objects for for industrial ，, medical. medical , oror other other purposes ,， bothbot h microscopic microscopic andan d macroscopic.macroscopic . Th e applications applications include include engineering engineering design ，, biological biologica l studies ，, nondestructive nondestructive nondestructive inspection inspection andan d materials materials evaluation. evaluation. In In thethe pastpast decade ,， overove r 10010 0 di differen恥 rent t centers centers in in somesom e 303 0 countries countries havehav e publishedpublished reports reports of of pioneering pioneerin g activities activities using usingusing reactors ,， accelerators accelerator s andan d isotopic isotopic neutronneutron sources. sources. While While film film transparency transparency andan d electronic electronic electronic videovideo areare mostmos t ∞commommon n imagingimagin g methodsmethod s for fo r static static oror in in motionmotio n objects ,， respectively ,， there ther e areare other other important important data data gathering gathering techniques ,， including includin g track track etch ,， digital digital digital gauginggaugin g andan d computedcompute d tomography.tomography . A surveysurvey of of thethe world-wideworld-wide progress progress showshows s ththe e fielfield d tto o bbe e gainingaining g steadilsteadily y iin n itits s diversity,，批 its sophisticatiosophistication n anand d its its impoimportanceはance. . INTRODUCTIONINTRODUCTIO N

It It I t is is ana n honorhono r to to presentpresen t this this invited invited paperpape r reviewing reviewing neutron neutron radiography radiography within within this this thi s international international conferenceconferenc e entitled entitled NeutronsNeutron s asa s MicroscopicMicroscopic Probes. Probes. MostMos t ofof thethe paperspaper s in in thethe conferenceconferenc e discussdiscuss scattering scattering techniquestechniques to to studystudy microscopic microscopic details details of of of crystal crysta l structure. structure. NeutronNeutro n radiographyradiography sharesshare s a commoncommo n interest interest in in neutronneutron sourcessource s andan d neutronneutron physics ,， butbu t it it usesuse s thethe microscopically microscopically small small neutronneutron primarily primarily to toto obtain obtain macroscopicmacroscopi c information. information. TheTh e optically optically enlargedenlarged imageimag e showingshowin g individual individual boronboro n fibers fibers in in a metalmetal compositecomposit e provides provides ana n exampleexampl e of of thethe small small scale scale neutron neutron radiographyradiograph y capability. capability. A neutronneutron radiographradiograph of of a full full size size motorcyclemotorcycle hasha s beenbee n useduse d to to to iII illustrat ustrate e thethe larger larger scale scal e possibilities. possibilities. NeutronNeutro n radiographyradiography dependsdepend s ono n theth e ability ability of of neutronneutron radiation radiation to to penetrate penetrate certain certain certain materials material s (typically (typically densedens e metals) metals) moremor e readily readily thanthan enclosedenclose d elementselement s of of interest interest interes t (typically (typically thosethos e containing containing hydrogen). hydrogen). TheTh e techniquestechniques canca n sometimessometime s provide provide impoimportan同ant t information information that that cannotcanno t beb e obtainedobtained byb y conventional conventional X-radiographyX-radiography oror alternative alternative alternative inspection inspection methods.methods . In In mostmos t casescase s thethe spectrumspectru m of of predominantlypredominantly thermal thermal neutrons neutrons emergentemergen t fromfro m a moderatedmoderate d neutronneutron sourcesourc e will will provide provide thethe contrast contrast needed.needed . ofO f course ,， byb y selection selection of o f different different neutronneutron energies ，, theth e capabilities capabilities canca n beb e changedchange d significantly. significantly.

SOURCESSOURCE S

TheTh e neutronneutron beambea m is is usually usually 号extractextracted d throughthroug h the the sourcesourc e shielding shielding usingusing a divergent divergent divergen t collimator collimator design. design. TheTh e neutronneutron f1 fluux x incident incident ono n thethe object object is is thethe f1 fluux x at at thethe

-125- collimator collimator collimator input input reducedreduce d byb y the the squaresquare of of the th e collimator collimato r ratio ratio of of length length L to to input input diameter diameter diameter D. D. Neutron Neutron Neutro sources n sources ranging ranging fromfrom very ver high y high flux flux to to relatively relatively lowlow flux flux eacheac h havehav e a role role role to to play play in in neutron neutron radiography. radiography. At At the the enden d of o f this this conferen conferenc回e wewe shall shal l visit visit the the high high high flux flux reactor reactor JRRJRR-・3 whichwhich has has three thre e operational operational neutron neutron radiography radiography systems，, oneon e for for for nuclear nuclear fuel fuel studies ,， another anothe r for for nonno n radioactive radioactive material material studies ,， andan d a cold cold neutron neutron 回capabilitypability. . 刊The reactors reactors JRRJRR-・2 (10 (10 MMW) W)， , JRRJRR-・4 (3.5 (3.5 MMWW) ) andan d NSRRNSR R (pulsed (pulsed reactor) reactor) reactor) at at JAERIJAER I havehav e also also beenbee n applied applied to to neutron neutron radiography. radiography. Saclay Saclay andan d Petten Petten are are are other other centers centers that that havehav e high high flux flux reactors reactors with wit h facilities facilities designeddesigned for for fuel ,， thermal therma l andan d cold cold neutron neutron radiography. radiography. SandiaSandia National National LaLaborator boratory y in in the the USAUS A hasha s ana n annular annular core corecore pulsed pulsed reactor reactor neutron neutron radiography radiograph y capability capability comparablecomparabl e with with NSRRNSR R (T (Tabl able e 1)1). . LowLo w cost cost reactors reactors suchsuc h asa s the the 10 10 KWKW L88L8 8 solution solution type type in in the the USA ，, the th e MIRENEMIREN E reactor reactor reactor in in France ，, andan d the the 1W W reactor reacto rat at Ki Kink nki iUnive Universit陪 ity y in inJapan Japancan can also also ~eb e use!ul useful for for fo r certain certai n applications. applications. TheTh one e one watt wat t reactor reactor provides provides a neutron neutron flux flux of of 3x1033n/cm 22--s s atυoat L/ D 22. 22 . In In Taiwan Taiwan the the sos o called called zero zero powerpowe r reactor reactor hasha s beenbee n recently recently upgradedupgrade d to to 303 0 KWK W specifically specifically to to meetmee t various variou s industrial industrial neutron neutron radiography radiography demands.demands .

TABLETABL E 1 ComparableComparabl e NRNR SystemsSystem s ・- ApproxlmateApproximate Flgures Figures

'-i 22 NRTYPENRTYP E CENTERCENTE R REACTORREACTO R L:D L:D n/cm --s s

88 ETherma皇国E盟l JAERI JAERI JRRJRR- -3 3 170 170 2x2x1010

77 PETTENPETTE N HFRHF R 40040 0 2x2x1010

77 SACLAYSACLA Y OSIRIS OSIRIS 150 150 6x6x1010

88 SANDIA SANDIASANDIA ACPRACP R 110 110 2x2x1010

88 Cold Cold Cold JAERI JRRJRR- -3 3 GUIDE GUIDE - 2x2x1010

55 PETTENPETTE N HFR-FILTER HFR-FILTER 150 150 2x2x1010

99 SACLAYSACLA Y ORPHEE-GUIDEORPHEE-GUIDE - 1x10

Pulsed Pulsed Pulsed JAERI JAERI NSRRNSR R 30 30,00，∞ o0 MWMW approx. approx.

SANDIA SANDIASANDIA ACPRACP R 30 30,00 ，000 0 MWMW approx. approx.

Accelerators Accelerators Accelerators in in useus e for for neutron neutron radiography radiography include include cyclotrons ,， vanva n ded e graaff graaff machines ，, andan d sealed sealed tubetube neutron neutron generators. generators . In In JapJapan聞， , of of twenty twenty operating operating neutron neutron radiography radiography radiography systemssystem s nine nine useus e accelerators. accelerators. HighHigh yield yield 0- D-T accelerators accelerators andan d special special radio radio radio frequency frequency quadrupolequadrupol e accelerators accelerators are are being being developeddeveloped for for neutron neutron radiography radiography applications applications applications in in EuropeEurop e andan d the the USUSA A. . Also Also Also isotopic isotopic neutron neutron sources ,， principally principall y Californium-252 Califomium-252,， are ar e being being appliedapplied. .

-126-126- ー Th e neutron neutron beambea m flux flux ofof thethe 505 0 mgmg cfCf-25・252 2 sourcesourc e in in useus e for for aircra aircraf仕t inspection inspection is is similar similar similar to to that that detailed detailed aboveabov e for for thethe 1 WattWat t reactor. reactor.

， IMAGINGIMAGIN G

FourmFour majo司or r categories categories of of neutronneutro n imagingimagin g technologytechnolog y havehav e beenbee n developeddevelope d sos o far. far. far. TheTh e direct direct exposureexposur e techniquetechniqu e usesuse s a neutronneutron converter ,， suchsuc h asa s vaporvapo r depositeddeposite d gadolinium ，, heldhel d byb y a vacuumvacuu m casse' cassett世e against against fine fine grain grain single single emulsionemulsio n radiographic radiographic film. film. film. A typical typical exposureexposur e requires requires 10 99n/cm 22 andan d providesprovides a -resolution resolution comparablecomparabl e in in quantity quantity quantity to to thethe finest finest grain grai n industrial industrial oror medicalmedica l X-rayX-ray film. film. ImageImag e quality quality standardsstandard s havehav e beenbee n developeddevelope d sos o that that film film neutronneutro n radiographyradiograph y canca n provideprovide approvedapprove d quality quality control control control for for inspections inspection s critical critical toto the the safety safety of of systemssystem s suchsuc h asa s aircraft ,， spacespac e rockets rockets or oror nuclearnuclear reactors. reactors. TheTh e secondsecon d categorycategor y of of neutron neutron detection detection is is thethe activation activation transfer transfer method,， wherewher e dysprosiumdysprosiu m oror indiumindiu m converter converter sheetssheet s enableenabl e a highly highly radioactive radioactive object object to to beb e neutronneutro n radiographedradiographe d without without gammagamm a radiation radiation reachingreaching andan d foggingfoggin g thethe film. film. TheTh e third third third categorycategor y is is track track etchetch imagingimagin g wherewher e a neutron neutron conveconverterはer ,， typically typically boron ，, is is exposedexpose d to to the the neutron neutron beambea m together together with with a cellulose cellulose nitrate nitrate sheesheet t. . TheTh e sheetshee t is is later later chemically chemically chemically etched. etched. ThisThis methodmetho d is is also als o insensitive insensitive to to gammagamm a rayray interference ,， andan d is is of of of particular particular valuevalue wherewher e highhigh precision precision dimensionsdimension s are are neededneede d for for nuclearnuclear fuel fuel swelling swelling swelling measurements.measurements . TheTh e fourth fourth neutron neutron imagingimagin g categorycategor y is is dynamicdynami c imagingimagin g wherewher e a scintillator scintillator andan d video video chainchain areare useduse d toto provideprovide imagesimage s ono n a television television monitor. monitor. monitor. SuchSuc h electronic electronic imagingimagin g lendslend s itself itself to to ∞computemputer r processingprocessin g andan d color color enhancemenenhancement t. . BothBot h film film andan d electronicimagingelectronic imaging techniquestechnique s havehav e beenbee n extendedextende d to to provide provideprovide neutron neutron computedcompute d tomographytomograph y for for special specia l applications. applications.

HISTORICALHISTORICA L CYCLESCYCLE S

It It It waswa s at at a neutronneutro n scattering scattering conferenceconferenc e similar similar to to this ,， but bu t in in LondonLondo n in in 1961 ，, that tha t the the ideaidea of of neutronneutro n radiographyradiography 自firsrst t occurredoccurre d to to this this author. author. Dr. Dr. Bacon ，, author autho r of of ana n early early early bookboo k ono n neutronneutro n diffraction ,， describeddescribe d howho w crystal crystal monochromatorsmonochromator s werewer e lined lined upu p with with reactor reactor beamsbeam s byb y noting noting thethe shadowshado w ono n a film. film. CouldCoul d suchsuc h neutron neutron beamsbeam s andan d imagingimagin g openope n for for medicalmedica l applications applications a wholewhol e newne w field field similar similar to to XX-radiography・radiography? ? After After After somesom e monthsmonth s of of experimentingexperimenting,， alonealon e in in EuropeEurop e at at that that time ,， it it waswa s discovered discovered that that that KallmanKallma n in in Berlin Berlin andan d ThewlisThewlis in in Harwell Harwell hadha d previo'Jsly previously written written ono n thethe subject. subject. IndependentlyIndependentl y McGonnagle ,， Watts ，, andan d BergerBerge r werewer e starting starting workwor k in in Chicago.Chicago . SinceSinc e that that that st star制 t to to overove r 303 0 yearsyear s of of continuouscontinuou s effort effort there there hasha s beenbee n Ii悦 littlle e overlapoverlap betweenbetwee n the the conferenceconferenc e schoolsschool s of of neutronneutro n scattering scattering andan d neutronneutro n radiography. radiography. It It is is appropriate appropriate appropriate thenthe n to to return retur n full full cycle cycle in in reporting reporting backbac k to to you.you. NeutronNeutro n radiographyradiograph y andan d neutronneutro n scattering scattering shareshar e manyman y commoncommo n interests interests in in addition addition toto sharedshare d utilization utilization of of neutronneutro n sources.sources. 有Th1e e history history of of neutronneutro n radiographyradiograph y developmentdevelopmen t is is recordedrecorde d in in 胎its publications. publications. In In In the the fir firs説t 3030 years ,， 19321932-196 ・1962 2 there there werewer e relatively relatively fewfe w publications publications Oust (jus t five five oror so) ,， butbu t betweenbetwee n 1963196 3 andan d 1993199 3 the th e activity activity expandedexpande d significantly significantly asa s summarizedsummarize d iiD_~n a direct direct direct mail mail neutronneutro n radiographyradiograph y newsletter newsletter'仰: 1', andan d in in a saries series of o f topical topical conferencesconferences' C2 2-8). "8'. TableTabl e 2 showsshow s the th e distribution distribution oftheo f the eighty eighty researchresearc h institutes institutes andan d industries industries in in twenty twenty

-127-- 127- TABLTABLE E 2

CenterCenters s Reportin Reporting g aat t ththe e FourtFourth h WorlWorJd d ConferenceConferenc e oon n NeutroNeutron n Radiography,， MaMay y 1991992 2

USUSA A JAPAJA?AN N WW. . EUROPEURO?E E OTHEOTHER R

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-128- three threthree e countriecountries s reportinrepo 凶ng g iin n ththe e FourtFourth h WorlWorld d ConferencConference e oon n NeutroNeutron n RadiographyRadiograph y currently currentlcurrently y iin n ththe e publicatiopublication n processprocess. .

ENERGENERGV Y APPAPPLICATIONLl CATIONS S

ThThe e valuvalue e oof f neutroneutron n radiographradiography y researcresearch h anand d developmendevelopment t iis s realizerealized d whenwhe n it iit t leadleads s tto o applicatioapplication n fofor r importanimportant t problemsproblems. . IIn n thithis s reviereview w wwe e wilwill l starstart t witwith h thethe contribution contributiocontribution n oof f neutroneutron n radiographradiography y tto o ththe e fielfield d oof f nucleanuclear r energyenergy. . NeutronNeutro n radiography radiographradiography y oof f highlhighly y radioactivradioactive e nucleanuclear r 伽fueel l specimenspecimens s cacan n bbe e performepe 斤Ormed d using using massivmassive e shippinshipping g caskcasks s witwith h externaexternal l reactoreactor r beambeams s or,， mormore e conveniently ,， underwateunderwater r systemsystems s sucsuch h aas s aat t ththe e SaclaSaclay y OsiriOsiris s reactor,， wherwhere e ftωJe fue創l1 specimenspeci 耐加mens s canca n bbe e easileasily y movemoved d frofrom m ththe e corcore e irradiatioirradiation n positioposi 比削 t討ion n ωto i川inspectionspe 凶 。n anand d backback. . ThThe e importancimportance e oof f neutroneutron n radiographradiography y fofor r studiestudies s oof f nucleanuclear r fuefuel l beforbefore e oor r afteafter r irradiation irradiation hahas s beebeen n sucsuch h thathat t severaseveral l nucleanuclear r reactorreactors s havhave e beebeen n builbuilt t especiallespecially y fofor r 伽fueel l neutronneutron radiography. radiographyradiography. . ExampleExamples s arare e aat t CadarachCadarache e iin n France,， anand d aat t ththe e ArgonnArgonne e HoHot t CelCell l complecomplex x iin n ththe e USAUSA. . SomSome e exampleexamples s oon n neutroneutron n radiographradiography y applicationapplications s tto o nucleanuclear r fuefuel l studies studies include include includ e identification identification of of clad cla d failure failure byb y waterwater ingress ，, measurementmeasuremen t of of external external fuel fuel pellet pellet pellet dimensional dimensional changes ,， andan d examination examination of o f fuel fue l internal internal changeschange s using using epithermal epithermal neutrons. neutrons. neutrons. AccidentAccident behavior behavior studies studies suchsuc h asa s loss loss of of coolant coolant simulations simulations areare also also evaluated evaluated evaluated usingusing neutronneutron radiography. radiography. TheTh e plansplans in in JapanJapa n concerningconcerning fast fast breeder breeder powerpowe r reactors ,， highlighted highlighte d recently recently recently byb y a majormajo r shipmentshipmen t of of plutonium plutonium fromfro m France ，, invites invite s mentionmentio n of of the th e ability ability of of of neutronsneutrons for for studies studies of of plutonium plutonium fue fuel l. . TheTh e freshly freshly manufacturedmanufacture d mixedmixe d oxide oxide fuel fuel for for for thethe FastFast Flux Flux TestTest FacFacilit日比 y at at HanfordHanfor d waswa s inspected inspected oneon e hundredhundre d percentpercent byb y a specially specially speciall y installed installed Triga Triga reactor reactor using using a large large areaare a vertical vertica l collimator. collimator. This This canca n provide provide checkscheck s against against misplacedmisplace d blanket blanket pellets ，, unacceptableunacceptable pellet pellet vOids voids，, andan d unacceptableunacceptabl e size size of of plutonium plutonium oxide oxide agglomerations. agglomerations. Studies Studies of of plutonium plutonium fuel fuel behavior behavior behavior in in accident accident conditions conditions provide provide results results that that canca n beb e eveneve n moremor e dramatic. dramatic. Technologies Technologies applicable applicable to to fast fast breeder breeder reactor reactor developmentdevelopmen t include include computedcompute d tomographytomograph y of of fuel fuel bundles ，, andan d useus e of of the the fast fast neutron neutron hodoscopehodoscop e at at the the ArgonneArgonn e Treat Treat Treat reactor reactor to to imageimag e the the fission fission neutron neutron papatter枕:ern n emergingemergin g fromfro m a fuel fuel assemblyassembl y in in test test test conditions. conditions. NeutronNeutro n radiography radiography evaluation evaluation of of rawra w zirconium zirconium required required for for manufacturemanufactur e of o f fuel fuel rod rod cladding cladding hasha s beenbee n undertaken undertaken ono n a massivemassiv e scale. scale. ByB y useus e of of subthermal subthermal neutronsneutrons the the cryst crystallin剖line e zirconium zirconium is is rendered rendere d relatively relatively transparent transparent andan d small small smal l impurities impurities suchsuc h asa s hafnium hafnium canca n beb e detected. detected. A special special cold cold neutron neutron source source systemsyste m uusin g liquid methane was installed on a Mark F Triga reactor at the General Atomics Company for this application.

TRANSPORTTRANSPOR T APPAPPLICATIONLl CATIONS S

TheTh e safety safety of of eacheac h jet je t aircraft aircraf t flight flight dependsdepend s ono n thousandsthousand s of of turbine turbine blades blades makingmakin g millions millions of o f revolutions revolutions without withou t failure. failure. ToT o eliminate eliminate the the risk risk of of a turbine turbine bladeblade coolant coolant coolant channel channel being being blockedblocke d at at manufacture，, every ever y bladeblade is is inspected inspected using using neutron neutron radiography. radiography. radiography. NeutronNeutro n radiography radiography of of thesethese expensive expensive but but impoimportan同:ant t turbine turbine bladesblades is is a major majo r international international business business involving involving nuclear nuclear reactors reactors in in Asia Asia，, EuropeEurope ，, andan d North North

-129-- 129- America. America.America. In In addition addition to to routine routine inspection inspection for for blockageblockag e of of coolant coolant channels ，, special specia l interests interests interests could could include include hydride hydride embrittlement embrittlement of of thethe titanium-aluminum titanium-aluminum alloy alloy in in jet jet engine fan fa blades. n blades. NeutronNeutro n computedcompute d tomographytomograph y hasha s beenbee n indicated indicated asa s a tool tool in in crashedcrashe d aircraft aircraf t investigations investigations involving involving failed failed jet jet engines. BecauseBecaus e critical critica l control control panelspanels of of modernmode m aircraft aircraft areare constructed constructed of of paperpape r thin thin aluminum ,， andan d becausebecaus e this this aluminumaluminu m canca n corrodecorrod e if if mOistmoist,， maintenancemaintenanc e inspections inspections for for for hydrogenhydroge n aluminumaluminu m corrosion corrosion canca n beb e important important to to ensureensur e air air worthiness worthiness overover airframe airframe airfram e lifetimes lifetimes that that mayma y exexcee回阿部d 20 years. years. TheTh e aluminumaluminu m corrosion corrosion product product contains contains hydrogenhydroge n that that canca n beb e revealed revealed byb y neutronneutron radiography. radiography. AnA n Air Air ForceForc e maintenancemaintenanc e center center center in in thethe USAUS A hasha s recently recently constructed constructed twotw o neutronneutron radiographyradiography systems ,， oneon e using usingusing a maneuverablemaneuverabl e californium-252 californium-252 neutronneutron sourcesourc e together together with with robotics robotics to to obtain obtain scansscan s ofo f intact intact aircraft ,， andan d thethe other other a higher higher flux flux Triga Triga reactor reactor neutronneutron sourcesourc e for for higher higher highe r sensitivity sensitivity inspection inspection of of detacheddetache d pal1s. pads. HiddenHidde n moisturemoisture andan d honeycombhoneycom b corrosion corrosion corrosion that that cannotcanno t beb e detecteddetected byb y X-rays X-rays is is clearly clearly seensee n usingusing this this neutron neutron radiography. radiography. radiography. OneOn e of of theth e first first types types of o f aircraft aircraft inspected inspected hasha s beenbee n thethe F-15 ,， ana n aircraft aircraft that that tha t is is also also of o f interest interest to to thethe Mitsubishi Mitsubish i aircraft aircraft maintenancemaintenanc e division division in in Nagoya ，, Japan. Japan . TheTh e question question of o f applicability applicability of of neutronneutron radiography radiography to to commercialcommercia l aircraft aircraft maintenancemaintenanc e is is a subject subject for for future future study. study.

FOODFOO D ANDAN D SHELTERSHELTE R APPAPPLICATIONLl CATIONS S

ResearchResearc h that that improvesimprove s foodfoo d production production mayma y rankrank in in importanceimportanc e alongalon g with with energyenerg y andan d transpotranspor同t in in viewvie w of of thethe increasing increasing worldworld population. population. NeutronNeutro n radiographyradiography canca n provideprovide agronomistsagronomist s andan d soil soi l scientists scientists with with a uniqueuniqu e methodmetho d for for sequential sequential studies studies studies of of undistu undisturbe巾 ed d seedsee d germination ,， plant plan t root root growth ,， andan d moisture moisture uptake in in controlled controlled controlled conditions conditions suchsuc h asa s simulation simulation of o f frosts frosts andan d droughts. droughts. Valuable Valuable workwor k in in this this area area hasha s beenbee n performedperforme d recently recently at at thethe University University of of TokyoToky o in in collaboration collaboration with with RikkyoRikky o Universi University恥, in in addition addition toto workwor k in in several several other other countries. countries. NeutronNeutro n radiographic radiographic methodsmethod s areare also also being being developeddevelope d to to improveimprov e building building methodsmethod s with with porousporou s materials materials suchsuc as h as concreteconcrete andan d brick. brick. WaterWate r permeability permeability of of importanceimportanc e to to dams ,， bridgesbridge s andan d other other building building foundations foundations hasha s beenbee n studied studied this this waywa y in in bothbot h Austria Austria andan d China. China. NeutronNeutro n radiographyradiography hasha s beenbee n developeddevelope d in in GermanyGerman y to toto study study cementcemen t andan d plastic plastic behavior behavior inside inside concrete. concrete. MethodsMethod s toto evaluate evaluate concreteconcrete microcracking microcracking microcracking havehav e beenbee n useduse d in in thethe USUSA A. . In In CzechoslovakiaCzechoslovaki a neutronneutron radiographic radiographic methodsmethod s are are officially officially standardized standardized for fo r testing testing water wate r protective protective agents agent s in i n building buildin g materials. materials.

HEALTHHEALT H ANDAN D CONSUMERCONSUME R PRODUCTPRODUC T APPAPPLICATIONLl CATIONS S

Several Several Several centers centers havehav e reported reported thethe useus e of of neutronneutron radiographic radiographic techniquestechniques for for research researchresearch in in medicinemedicin e andan d biology. biology. OneOn e application ,， for fo r example ,， involved involve d ana n operation operation ono n a personperso n to to removeremov e sections sections of of jawja w bonebon e containing containing hiddenhidde n cancer. cancer. AnotherAnothe r study study in in in JapanJapa n providedprovided information information ono n thethe causescause s of of gallstone gallstone formation. formation. NeutronNeutro n radiography radiographyradiography is is also also being being developeddevelope d asa s a tool tool in in dentistry dentistry research. research. NeutronsNeutron s can ，, for fo r example ,， penetrate penetrat e metal metal crownscrown s to to reveal revea l internal internal dental dental defects. defects. Also ，, becausebecaus e neutrons neutronsneutrons penetrate penetrat e relatively relatively densedens e tooth tooth material material andan d reveal revea l soft internal internal soft tissue ,， neutron neutronneutron radiography radiography canca n help help developdevelo p root root canal canal andan d other other endodonticsendodontic s technology. technology.

-130- 130-ー ExamplesExample s of of general general consumerconsume r productproduct industry industry applications applications for for neutron neutron radiography radiographyradiography include studies include studies of of solders ,， brazing brazin g andan d welding. welding. AnotherAnothe r exampleexampl e is is the the developmdevelopmen己nt t of of tennis tennis racket racket technologytechnology wherewher e neutronsneutrons havehav e theth e ability ability to to seese e boronboro n fiber fiber fiber delaminations delaminations in in a graphite graphite matrix. matrix. OneOn e major majo r application application for for neutronneutron radiography radiography is is is monitoring monitoring of o f cigarette cigarette manufacturemanufactur e procedures. procedures. NeutronNeutro n radiographyradiography techniquestechniques havehav e beenbee n developeddevelope d andan d applied applied for for studies studies of of o f archeological archeological objects objects andan d other other museummuseu m treasures. treasures. OneOn e techniquetechnique for for paintings paintings iis s to to to imageimag e the the ionizing ionizing radiation radiation resulting resulting fromfro m neutron neutro capture n capture，, a methodmetho d whichwhic h canca n reveal reveal reveal hiddenhidde n layers layers of of the the artists artists workwor k andan d help hel p differentiate differentiate forgeries. forgeries. Forensic Forensic science sciencescience andan d security security systemsyste m supportsupport to to complementcomplemen t thermal thermal neutron neutron activation activation are are other other other areasareas that that are are beingbeing considered. considered. DynamicDynami c imagingimagin g neutronneutron radiography radiography 1s is beingbeing developeddevelope d for for numerousnumerou s industrial industrial industria l applications. applications. In In EnglandEnglan d cold cold neutronneutron dynamicdynami c imagingimagin g waswa s useduse d to to studystudy oil oil oil flow flow in in operating operating jet je t aircraft aircraft engines. engines. CompaniesCompanie s in in HungaryHungar y that that designdesign improvedimprove d absorption absorption andan d compressioncompressio n refrigerators refrigerators refrigerators havehav e useduse d neutronsneutrons to to studystudy the the behavior behavior of o f lubrication lubrication andan d cooling cooling oil oil asa s pressure ,， temperature ,， flow flo w rate rate andan d other other parametersparameter s are are varied. varied. In In FranceFranc e designdesign workwor k ono n hydrocarbonshydrocarbon s (HFC)(HFC ) to to replace replace the the stratospheric stratospheric polluting polluting chloro-fluoro ・- carbonscarbon s (CFC)(CFC ) in in compressorcompresso r typetype automotive automotive air air conditioner conditioner hasha s relied relied ono n neutron neutron radiography radiographyradiography to to evaluate evaluate problemsproblem s suchsuc h asa s nonno n miscible miscibl e oil-liquid oil-liquid refrigeran refrigerantt.判. Th1eliquid e liquid flow , ， liquid liqui d evaporation ,， andan d thermal thermal exchangesexchange s are are seriously seriously altered altered byb y anyan y oil oil separation. separation. separation. AlsoAlso oil oil accumulation accumulation in in the the evaporator evaporator endangersendanger s theth e lubrication lubrication of of the the compressor.compressor . TheTh e mostmos t extensive extensive workwor k ono n dynamicdynami c imagingimagin g neutron neutron radiographyradiography is is beingbeing carried carried carried outout in in Japan.Japan. TeamsTeam s at at MusashiMusash i Institute Institute of of TechnologyTechnolog y andan d the the University University of of TokyoToky o havehav e workedworke d ono n systemssystem s development ,， andan d scientists scientists at at KyotoKyot o University University havehav e studied studied studied boiling boiling two-phasetwo-phas e flow flow in in narrownarro w channelschannels related related to to nUClear nuclear fusion fusion reactor reactor blanket blanket blanke cooling t cooling design. design. 50meSom of e of this this workwor k hasha s useduse d thethe NuclearNuclear 5afety Safety ResearchResearc h Reactor ReactorReactor 内'NSRR5RR) ) at at JAERIJAER I in in pulsedpulsed modemod e with with a videovideo cameracamer a operableoperable to to 10100∞0 framesframe s per per second.second . 5tudies Studies include include gas-solid gas-solid spoutedspoute d bedsbed s suchsuc h asa s are are useduse d for for driers driers driers of of foodfoo d grains ,， andan d liquid liquid solid solid spoutedspoute d bedsbed s that that havehav e application application in in high high heatheat transfer transfer transfer systems.systems. A team at at KobeKob e University University hasha s studied studied multiphase multiphase flow flow andan d void void fri fri fraction in water-aluminum systems, and visualization of streak lines for thermal hydraulic design of lead-bismuth eutectic.

HIGHHIG H TECHNOLOGYTECHNOLOG Y APPLICATIONSAPPLICATION S

A typical typical blockblock valve valve hasha s a bodybod y of of aluminumaluminu m with with telescoping telescoping slip slip rodsrods of of steel steel steel andan d a set set of of nylon nylon gaskets gaskets or o r o-rings. o-rings. NeutronNeutro n radiography ,， unlike unlik e X-rays ，, canca n reliably reliably reliably showsho w if if a vital vital "0" "o" ring is is missing. missing. AII Al l pilot pilot ejection ejection mechanismsmechanism s in i n military military aircraft aircraft aircraft are are inspected inspected using using neutron neutron radiography. radiography. OneOn e papar同t is is the the explosive explosive train train encasedencase d in in silver silver wherewher e anyan y gapga p couldcould causecaus e a failure. failure. Ot Othe her r critical critica l pyrotechnical pyrotechnical items items items areare inspected inspected for for missing missing explosive explosive charge. charge. RocketsRocket s useduse d for for communicationscommunication s or oro r military militar y satellites satellites canca n require require neutron neutron radiography radiography ono n overover 505 0 different different items items for for eacheac h launch. launch. TheTh e explosive explosive bolts bolts are are oneon e exampleexampl e werewer e bothbot h neutronneutron radiographyradiography andan d X radiographyradiography areare neededneede d to to provide provide a thoroughthoroug h examination. examination. TheTh e complementarycomplementar y

-131-- 131- nature nature nature of of N-rayN-ray andan d X-raX-ray y iis s also also apparent apparent fofor r thethe probingprobing of of detonatordetonators s andan d fusesfuses. . Automotive air air bagba g mechanismsmechanism s andan d commercialcommercia l aircraft aircraft escapeescap e devices devices areare examplesexample s of of of items items that that mustmus t workwor k ono n demand ,， andan d therefore therefore ∞coul uld d justify justify both both N-rayN-ray andan d X-ray X-ray inspection. inspection. inspection. For For manyman y detonators detonators andan d relays relays a comparisoncompariso n of of X-ray ，, thermal therma l N-ray N-ray，, andan d cold cold cold neutronneutron radiograph radiograph hasha s provenprove n valuable. valuable.

SUMMARYSUMMAR Y

NeutronNeutro n radiographyradiography methodsmethod s that that areare beingbeing pioneeredpioneered at at the the JapaneseJapanes e AtomicAtomi c EnergyEnerg y ResearchResearc h Institute ,， andan d that tha t will will beb e visited visited asa s paparはt of o f this this conference ,， include: include : (1) (1) (1) thermal thermal andan d epithermal epithermal neutron ，, gammagamm a insensitive insensitive imaging ,， for fo r developmentdevelopmen t of of powerpowe r reactor reactor nuclear nuclea r tuels; fuels; (2) (2) thermal thermal neutron neutron radiographyradiography for for direct direct 制film imaging imaging of of of non-radioactive non-radioactive objects; objects; (3) (3) cold cold neutron neutron radiographyradiography for for evaluation evaluation of of non-non­ radioactive radioactive radioactive objects; objects ; (4) (4) pulsedpulsed reactor reacto r applications applications for for neutronneutron radiographyradiography requiring requiring very very very highhigh flux; flux; (5) (5) videovideo methodsmethod s of o f electronic electronic imagingimagin g for for dynamicdynami c studies studies with with neutron neutronneutron radiography; radiography; (6) (6) computedcompute d tomographytomograph y methodsmethod s for for neutronneutron radiographyradiography of of either either eithe r radioactive radioactive or or non-radioactive non-radioactive objects. objects. 判官The techniquestechniques canca n help help meetmee t needsneed s in in fields fields asa s impoimportanはant t andan d diverse diverse asa s energyenerg y supply ,， transpotransport 同， , foodfoo d andan d shelter ,， medicine ,， consumerconsume r products ,， andan d various various high high high technologies. technologies. In In eacheac h casecas e twotw o distinct distinct roles roles should should beb e considered: considered: (1(1) ) nondestructive nondestructive nondestructive testing testing ono n thethe finished finished product product andan d (2) (2) useus e of of neutronneutron radiographyradiography to to help help help design design improvedimprove d products. products.

REFERENCESREFERENCE S

1. 1. 1. Neutron Neutron Radiography Radiograph y Newsletter Newsletter 1964 1964-77・77. . Compilation ，, J.P. J.P . Barton Barto n Editor. Editor . Distributed Distributed byb y the the AmericanSAmerican Societ∞ iety y of of Nondestructive Nondestructiv e Testing Testing (214 (21 4 pages). pages). 2. 2. 2. Radiography Radiography with with Neutrons ,， Conference ,， SepSe p 1973. 1973. M. M.R R. . Hawkesworth Hawkeswort h Editor. Editor . Published Published by by the the th e British British Nuclear Nuclear Energy Energy SSociety∞陶ty ,， 1975197 5 (167 (16 7 pages). pages). 3. 3. 3. Neutron Neutron Radiography Radiography andand Gaging ，, Conference ,， FebFe b 1975. 1975. H. H. Berger Berger EdEditor仕or. . Published Published by by American American American SSociet∞ iety y for for T. Testin田 ting g 釦and Materials ，, 1976197 6 (319 (319 pa! pages)伊 s). . 4. 4. 4. Neutron Neutron Radiography ,， FirsFirst t World World ConferenceConfl 自rence ,， DeDec c 19811981. . J.PJ.P. . BartoBarton n AI et et Al EditorsEd 柱。 rs. . Published Published by by by D. D . Reidel Reide l Publishing Publishing CompanyCompan y 1982198 2 (1072 (107 2 pages). pages). 5. 5. 5. Neutron Neutron Radiography ,， SecondSecon d World World Confer Conference自nce ,， Jun Jun 1986. 1986 . J.P. J.P. Barton Barton et et AI Al Editors. Editors. Published Published Published by by D. D . Reidel Reidel Publishi Publishin咽g CompanyCompany 1987198 7 (928 (92 8 pages). pages). 6. 6. 6. Neutron Neutron Radiography ,， ThThir ird d World World COnference Conference，, MayMa y 1989. 1989 . S. S. Fujine Fujine 倒et AI Al Editors. Editors . Published Published byb y KI Kluwe脚 er r Academic Academic Publish Publishers的，, 1987198 7 (928 (928 pagpages)同.. 7. 7. 7. Neutron Neutron Radiography ,， Fourth Fourt h World World Conference ,， MayMa y 1992. 1992 . J.P. J.P. Barton Barton Editor ,， to to beb e published. published. published. 8. 8. 8. Neutron Neutron Radiography Radiograph y Specialists Specialists Meeting Meeting in in Japan Japan 1992. 1992 . S. S. Fujine ,， H.H . Kobayashi Kobayash i Editors. Editors. Published Published Published by by Kyoto Kyot o University University KURRI KURRI-TR-359,1993・TR -3 59 ， 1993. .

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