Advanced Instrumentation for Transient Reactor Testing

Integrated Research ProjectMichael Corradini

University of Wisconsin, Madison

CollaboratorsIdaho State University

Kansas State UniversityOhio State University

Suibel Schuppner, Federal POCColby Jensen, Technical POC

Project No. 14-7353

IRPFInalReport:October2014toDecember2017

DoEProject#14-7353CID#DE-NE0008305

AdvancedInstrumentationforTransientReactorTesting

PrincipalInvestigatorMichaelL.Corradini

Professor,EngineeringPhysicsUniversityofWisconsin,MadisonWI53706

Corradini@engr.wisc.eduPhone:(608)263-1648

Co-PrincipalInvestigators:

MarkAnderson,Professor,UniversityofWisconsin-MadisonGeorgeImel,Professor,IdahoStateUniversityTomBlue,Professor,OhioStateUniversity

JeremyRoberts,Professor,KansasStateUniversityKurtDavis,Scientist,IdahoNationalLaboratory

ProjectPeriod:October2014toDecember2017

ReportingPeriod:October2014toDecember2017

January2018

INTEGRATEDRESEARCHPROJECTSUMMARYTransienttestinginvolvesplacingfuelormaterialintothecoreofspecializedmaterialstestreactorsthatarecapableofsimulatingarangeofdesignbasisaccidents,includingreactivityinsertionaccidents,thatrequirethereactorproduceshortburstsofintensehigh-powerneutronfluxandgammaradiation.Testingfuelbehaviorinaprototypicneutronenvironmentunderhigh-power,accident-simulationconditionsisakeystepinlicensingnuclearfuelsforuseinexistingandfuturenuclearpowerplants.Transienttestingofnuclearfuelsisneededtodevelopandprovethesafetybasisforadvancedreactorsandfuels.Inaddition,modernfueldevelopmentanddesignincreasinglyreliesonmodelingandsimulationeffortsthatmustbeinformedandvalidatedusingspeciallydesignedmaterialperformanceseparateeffectsstudies.Thesestudieswillrequireexperimentalfacilitiesthatareabletosupportvariablescale,highlyinstrumentedtestsprovidingdatathathaveappropriatespatialandtemporalresolution.Finally,thereareeffortsnowunderwaytodevelopadvancedlightwaterreactor(LWR)fuelswithenhancedperformanceandaccidenttolerance.Theseadvancedreactordesignswillalsorequirenewfueltypes.Thesenewfuelsneedtobetestedinacontrolledenvironmentinordertolearnhowtheyrespondtoaccidentconditions.Fortheseapplications,transientreactortestingisneededtohelpdesignfuelswithimprovedperformance.Inordertomaximizethevalueoftransienttesting,thereisaneedforin-situtransientreal-timeimagingtechnology(e.g.,theneutrondetectionandimagingsystemlikethehodoscope)toseefuelmotionduringrapidtransientexcursionswithahigherdegreeofspatialandtemporalresolutionandaccuracy.Therealsoexistsaneedfornewsmall,compactlocalsensorsandinstrumentationthatarecapableofcollectingdataduringtransients(e.g.,localdisplacements,temperatures,thermalconductivity,neutronflux,etc.).PROJECTOBJECTIVESTheabilitytomonitorfuelbehaviorinreal-timeisthefocusofourIntegratedResearchProject.Ourteameffortisaimedatprovidingmoreinformationonthetimeevolutionofthefuelrodstate,whichisimportanttodevelopathoroughunderstandingoftheunderlyingscienceoffuelbehavior.Suchmeasurementscouldalsoprovidereal-timedatathatcansubstantiallycomplimentsolerelianceonpost-irradiationexamination(PIE),whichonlyprovidesdataonthefinalstateoffuelrodcomponents.Ourresearchteamseekstodevelopanddemonstratespecificnewandinnovativemeasurementdiagnosticsforreal-timein-situmonitoringtosupporttransientreactortesting.Ourobjectiveshasthreekeyprogramelements:

• Developinnovativeconceptsthatleadtothedesignofthenextgenerationfuelmotionmonitoringsystemtosupporttransienttesting,takingadvantageof‘line-of-sight’corelayouts;i.e.,advancementsinspatialandtemporalresolutionforhodoscopeimaging.

• Developnovelinstrumentationtosupportin-piletransienttestingthatincludesfastresponsedisplacementandtemperaturemeasurements,thermalconductivitymeasurements,localfastandthermalneutronfluxmeasurements.

• Demonstratethesenovelinstrumentationmeasurementmethodsinareactor

environmentusinguniversityTRIGAreactorsaswellasdesignfortheiruseinatransienttestreactor.

Asdiscussedwithinouroriginalproposal,priortransienttestingexperienceindicatesthatthesensorsandmethodsidentifiedforinvestigationwithinthisprojectareimportantforobtainingmostoftherequiredkeyparametersanddatafromtransienttestsandformeetingdatavalidationneeds

ThisAdvancedInstrumentationforTransientReactorTestingIRPcombinestheexpertiseoffouruniversitiesandaleadingnationallaboratory(anditsuniqueinstrumentationlaboratoryandstaffexpertise)withaninternationalpartnerthatprovidesinstrumentationandtestrigs.TheIRPresearchteamfunctionsasamatrixedengineeringteamthatisfocusedonourfivedistincttaskareas:

• TaskI:Developmentofinnovationsforreal-time,‘line-of-sight’imagingforatransienttestusingthecurrenthodoscopeconceptwithadvancementsindetectionandimageresolution;

• TaskII:Developmentofnovelsensorstomeasurelocaldisplacementsandtemperaturesoffuelrodundertransientconditionsaswellaslocalmeasurementsofneutronfastandthermalflux;

• TaskIII:Out-of-piletestingofthesenovelsensorsunderacommontestprotocol

andgeometry;

• TaskIV:In-piletestingoftheseinstrumentsinaTRIGAreactortodemonstratethecapabilitytomeasurethesekeyparametersinaradiationenvironmentundertransientconditions;

• TaskV:PreliminaryDesignofStandardTransientReactorExperimentTestCapsules

withAdvancedInstrumentation.

PROJECTACCOMPLISHMENTSDURINGTHEPROJECTPERIODTaskI:HodoscopeTechnologyEnhancementsHodoscopeandCollimatorSupportThisresearchtaskatISUisfocusedonsimulationofthehodoscopeandcollimatorcombination,andcalibrationsupportfortheKSUdevelopmentoftheMPFDandtheMSND.Back-to-backfissionchamber(BTBFC)supportshavebeenmadetobettercontrolpositionandorientationoftheBTBFCwhenperformingcross-calibrationmeasurementswithKansasStateUniversity(KSU)fissilesamples.Thecurrentfocusincross-calibrationmeasurementsisreproducibilitygivenvariationsthatoccurbetweenmeasurementssuchasvoltagechange,detectororientation,samplepositioning.Hornyak-buttonAlternativesThreecandidatetechnologiesweremodeled,constructed,andtestedtovaryingdegrees.Thesetechnologiesincludedvariantsofmicrostructuredneutrondetectors(MSNDs)basedonhydrogenousoractinidereactants;devicesbasedonZnS(Ag)thatrepresentevolutionsoftheoriginalHornyakbutton;andaCF4H2-based,gas-scintillatordetector.Ofthesecandidates,thetwomostpromisingtechnologiestoemergewere(1)aparaffin-loadedMSNDand(2)adeviceconsistingofalternatinglayersofZnS(Ag)andLucitewithsilicon-photomultipliers(SiPMs)attachedatthesidesforlightcollection.BothdevicesweremodeledusingMCNPandGeant4(asapplicable).ThehydrogenousMSND(h-MSND)waspredictedtohaveanefficiencygreaterthan15%formono-directional,fission-spectrumneutronsandadevicelengthof5cmalongthebeampath.ThelayeredZnS(Ag)devicewaspredictedtohaveanefficiencyofapproximately3.5%fora5cmdevice.Forcomparison,theoriginalHornyakbuttonwasreportedtoexhibitefficienciesontheorderof0.1%.Theefficienciespredictedwerebasedonlower-leveldiscriminator(LLD)settingssufficientlylargetoachievesignal-to-noiseratiosof100foranassumedgamma-raybackgroundconsistentwiththeliterature.In-beamtestsattheKSUreactorconfirmedthattheh-MSNDcandetectfastneutrons.However,futuretestingwillrequirebeamfilterstoknockdowncontributionsfromthermalneutronsandgammarays.AlayeredZnS(Ag)devicewasconstructedandtestedusingaCf-252source.ThemeasuredefficiencycompareswelltopredictedresultsandoutperformedanexistingHornyakbuttonacquiredfromIdahoNationalLaboratory.TaskIIA:Micro-PocketFissionDetectors(MPFD)Micro-pocketfissiondetectors(MPFDs)havebeenafocusorcomponentofseveralongoing,DOE-supportedprojects.Theirsmallsizeandrelativeinsensitivitymakesthemidealforin-core,real-timemonitoringatavarietyofpowerlevels.Althoughtestswere(andcontinuetobe)performedearlyintheproject,thefocusshiftedmid-waythroughtheprojectfollowingdiscussionswithothers(includingG.ImelatISU).BecauseTREAT

transientsaresolarge,theresultingfluxesand,hence,fissionratescanbecomelargeenoughtodepositlargeamountsofenergyinasmallmass.ExperimentswereperformedintheKSUTRIGAreactortounderstandhowareactorpulseaffectsanMPFDreactant.Imagesofseveralaluminadiskswithnaturaluraniumdepositsweretakenbeforeandafterthereactorpulse.TheresultsconfirmthatthesurfacemorphologyofthedepositiondoeschangeandthatstudywouldbeneededpriortodeploymentinTREAT.RelatedWorkSeveralsmallereffortshavebeenundertakeninsupportofthetwoprimarygoals.First,aseniordesignteamwastaskedwithproducingamock-uphodoscopeforinstallationperpendiculartoathepenetratingbeamportoftheKSUreactor.TheteambasedtheirdesignontheexistinghodoscopeatTREAT,andhadexistingsteelplatesmilledwith4mmsquarechannelsboltedtogethertoprovidea25-channelcollimator.Ultimately,theteammadesomepoorassumptionsandwereunabletodevelopanin-beamtargettoprovideasufficient,fast-neutronsourcefortesting.However,thecollimatorremainsinplaceforfollow-ontestingshouldsuchanappropriatesourcebeacquired.Arelatedeffortwasmadetomodelandanalyzethepenetratingbeamport.Thisbeam'sspectrumisharderthantheotherbeamsbutisstillhighlythermal.TheKSUreactormodelwasextendedtoincludethefullextentofthisbeam.Advancedvariancereductiontechniqueswereappliedtoproduceestimatesofthebeamspectrum,whicharenowbeingusedtodesignanappropriatefilterforin-beam,detectortests.Somein-beamspectroscopyhasbeenperformedusingasetofBonnerspheres.Itisexpectedthisworkwillcontinueaspartofongoingeffortstoimproveestimatesofvariouscharacteristics.TaskIIB:DiamondDiodeTemperatureSensorInthistask,wehavesuccessfullyfabricatedaworkingdiamondthermistordeviceinsideastainlesssheathtube.Theoperationrangeofthethermistordevicewasfrom350OCto920OC. This has led to a patent disclosure as well as a journal article submission. Thismaximumtemperaturewasmainlylimitedbythesilverpaste,whichwasusedtoattachNbwires to themetal pad of the diamond. Themelting point of the paste is 960 OC at thepressureofatmosphericpressure,andthesilverpasteusedforourdevicesshowsfailureofelectricalconductionabove920OC.Workisstillcontinuingtoextendthethermistoroperationclosertothetheoreticallimitofthediamondthermistortonear2000OC.ThisworkiscontinuingwithcollaborationoftheHTTLteamatINLunderaseparateLDRDeffort.Toextendthemaximumtemperatureofthe diamond thermistor, we replaced silver paste with laser welding process to attachelectricwiretothemetalpad.Laserweldingprocessisaweldingprocessusingafocusedlaserpulseataweldingspot.Thediameterof the laserspotsize is100μmandthe laserpulse time is fewmsec,whichmakes thewelding occurs instantly on the targeted spot.However,anintermediatematerialisneedbetweenthemetalwireandthediamondmetal

padsincethethicknessofthediamondmetalpadisonly300nm.Toprotectthediamondfromthelaserpulse,wechoseNifortheintermediatematerial.ThemeltingpointoftheNiis 1455 OC, which is expected to increase the maximum temperature of the diamondthermistor operation. To deposit thick Ni pad on top of the diamond metal pads, weplannedtouseelectrolyticNiplatingprocessandsimulatedtheoptimumthicknessoftheNilayerrequiredforthelaserweldingprocess.Thelaserparameteris0.39Jforthelaserenergy,4msecoflaserpulsetimewhichresults97.5Watthe100μmdiameterofthelaserspot. The maximum temperature is over 9000 OC at the center of the spot. We furtherchanged Ni layer thickness to simulate the temperature at the interface between thediamondandtheNipad.Theinterfacetemperatureshowstemperaturesof96,127,172,250,415,575OCrespectivelyforNipadthicknessesof250μm,200μm,150μm,100μm,50μm,and25μm,respectively.AsthethicknessoftheNilayerincreases,thetemperatureattheinterfaceshowedless,whichhaslesschancetodamagethediamond.DuringtheNiplatingprocesstodepositthickNipad,werealizedNipadonlydepositsonthebacksideofthediamond,whichhadroughsurfaces.Thefrontsideofthediamondhassmoothsurface,whichdecreased the adhesionofmetal pad to thediamond.We intentionally roughenedthe front side of the diamond to make rough surface to increase the bonding area toimprovetheadhesion.Wehavemeasuredtheroughnessof thediamondsurfacewith3DopticalsurfaceprofilertoensurethesurfaceisroughenoughfortheNiplatingprocess.Theaveragesurfaceroughnesswas1nmbeforegrindingprocessand theaverageroughnessincreased to 240 nm after grinding. With roughened diamond samples, Ni pads weredeposited on both sides of the diamond for the laserwelding process toweld electricalwires.Forourfutureworkonthisthermistordevelopment,wewillcollaboratewiththeHTTLresearchteam.UsingtheINL’sfabricationprocess,wewillcharacterizethediamondthermistoroperationsathightemperatureranges.Anotherpromisingmethodtoreplacesilverpasteisusingdiffusionbondingprocess,whichcanreplacelaserweldingmethodaswell.Weareunderpreparingstageforthediffusionbondingprocessexperiments.TaskIIC:FiberOpticTemperatureSensorsFiber-optic sensors are being developed by both Ohio State (OSU) andWisconsin (UW).ThetechnologyleadwasOhioStateandWisconsinimplementedtheFiberOpticSensorsinout-of-pile and in-pile test vehicles and conducted integral experiments (Task III and IVsummarybelow).OhioStateresearchedthefeasibilityofusingfiberopticsasameansoftemperaturesensingin reactor transient environments. Ohio State investigated twodifferent typesof opticalfiber,silicaglass fibers(SiO2)andsapphiresinglecrystal fibers(Al2O3), foruse inTREATforthisIRPproject.SilicaOpticalFibersForsilicaglassopticalfibers,OSUfirsttestedcommercialsilicaopticalfibers(CorningSMF-28)tohightemperaturestodeterminethetemperaturelimitofdistributedsensinginthefiber. Experiments revealed that the commercial fiber had a distributed temperature

sensinglimitofaround700C.Abovethe700Cmark,variouseffectssuchasannealingofthe glass, atmospheric effects, and devitrification started to cause sensing failure in thefiber. By heat treating the fiber, the temperature range for distributed temperaturemeasurementsincommercialopticalfibercouldbeextendedto800Cforcontinuoususeand 900 C for short periods of time. Various microscopy techniques and numerousexperiments determined that the silica fiber was most affected by the atmospheresurrounding the fiber at high temperatures. By placing the silica fiber in an inert orvacuumenvironmentandhavingthefibersupportedwithamicrocapillarytubeorahightemperaturecoating,thedistributedtemperaturemeasurementrangeofcommercialsilicaopticalfibercanbeextendedto950C. For implementation into theTREATreactor, researchwasdoneonruggedizing thesilicaoptical fibers. Metal coated fiberswere experimentedwith, but unfortunately exhibitedstructuralfailureattemperaturesaround900C,duetothethermalmismatchbetweenthemetalandthefiber. Stainlesssteelcapillarytubeswerealsoinvestigatedasamethodforruggedizing the fiber, but the stainless steel oxidized at 800 C causing the fiber to fail.Usingadoubletubesetup,inwhichasilicamicrocapillarytubewasplacedinbetweenthefiber and the stainless steel capillary tube, enabled the fiber to produce distributedtemperaturemeasurementsupto950C.Thesilicamicrocapillarytubehadatightenoughtolerance with the fiber that airflow to the fiber was sufficiently reduced creating aneffective ‘inert/vacuum’ atmosphere around the fiber. The ‘inert’ atmosphere, combinedwith the extra strengthof the tube, enabledmeasurements tobemadewith commercialfiberto950C,whilealsoruggedizingthefiber. Silica optical fibers were also tested in a reactor environment (the Ohio State ResearchReactor) to determine the radiation hardness of the optical fibers. It was found thatdistributed temperature sensing fails in commercial optical fibers in a nuclear reactorenvironmentafteraneutronfluenceofaround1018n/cm2.OSUdiscoveredthatradiationhardnesscanbeaddedtothedistributedsensingabilityof the fibersby inscribingBragggratingsintothem.Type-IBragggratingswereshowntosurviveandproducetemperaturemeasurements for the entire duration of the reactor experiments conducted in theOhioStateResearchReactor,whichresultedinaneutronfluenceofaround2x1018n/cm2andagammadoseof2GRad.Type-IIBragggratingshavethemostpotentialforlongtermuseinanuclearreactor,sincetheywereshowntosurvivelongperiodsofhightemperatureandhighradiationfluencewithoutdegradation.InQ11,OSUwasinviteduptotheUniversityofWisconsintoparticipateinaheatedreactortransient experiment to test the optical fibers ability to survive in a TREAT likeenvironment. This experiment was designed to imitate the temperatures and radiationfluence that the fibers would experience in a TREAT experiment. To achieve theenvironmentofthisscenario,theWisconsinTRIGAReactorwasrampedquicklyto1MW,whilesimultaneouslyheatingthefibersinanenclosedtestvehicle.ThetestvehiclewasawatertighthousingthatwasbackfilledwithHeliumandcontainedaSiCheatertosimulatethehightemperaturesthatwouldnormallybeseeninaTREATtest.Thetestvehiclewasloweredintoabasketinthecoregridontheperipheryofthecore. Oncethetestvehicle

wassecureinthecorebasket,theheaterwasturnedupto400Cinsideofthetestvehicle.Shortlyafterreachingasteadystatetemperatureof400C,thereactorwasquicklyrampedto1MW. After 10minutes, the reactorpowerwasdroppedback to300watts and thisprocess was repeated at increasing temperature increments of 100 C until a 1000 Ctemperaturewasreached.Twodifferenttypesofopticalfiberwereusedinthisexperiment,CorningSMF-28fiberandType-I Bragg grating optical fiber with gratings every 1 cm. The temperaturemeasurements of the SMF-28 fiber seem to follow the temperature of the furnace veryaccuratelyuntilthereactorpowerwasrampedup.Duringreactorirradiation,thefiberhadnullmeasurementsabouteveryothermeasurement,whichresulted inameasurementofzeroforthetemperature.Oncethereactorwasturnedbackoff,themeasurementsofthefiber continued without the null measurements. This phenomenon occurred at eachtemperaturestepoverthedurationoftheexperimentuntil thetemperatureofthevesselhit900Catwhichpoint, the fiber failedcompletely. TheBraggGrating fiber,performedmuchbetterduringreactor irradiationcompared to thatof theSMF-28 fiber. TheBragggrating fiber did not produce the null measurements that the SMF-28 fiber producedduringreactorirradiation,andwasabletomaintainaconstanttemperaturemeasurementuntilthefibertemperaturehit800C.At800C,theBragggratingspartiallyannealedoutinthefiber,causingthefibertoproducenullmeasurementsduringreactorirradiation. TheBragg grating fiberwas able tomeasure temperatures up to 900C, before finally failingafter the second to last reactor transient. The optical fiber and thermocouplemeasurementsshowedgreatcorrelation(within5C)untilthetemperaturereached900C(at900C the fibermeasurements failed).Thehighaccuracyof theoptical fiberwith thethermocouple indicates that the use of optical fibers for temperature instrumentation intransientreactorenvironmentsisplausible.When the reactor was ramped up to full power, the SMF-28 experienced difficulties inmeasuringthetemperature.Weconcludethatthiswasduetotheneutronandgammafluxofthereactor,sincethetemperaturemeasurementsstabilizedoncethereactorwasturnedoff. The combination of high temperature and irradiation must have caused themeasurementsignaltoskewaswehaveneverseenthisbehaviorbeforewhenconductingroom temperature reactor experiments. The Bragg grating fiber was able to provide aconstantmeasurement,evenduringreactorirradiation,duetothehighsignaltonoiseratioof the reflections off of the Bragg gratings in the fiber. The Bragg gratings eventuallydegraded and annealed at temperatures of 800 C and so future experiments shouldinvestigate Type-II Bragg grating fiber. Type-II Bragg gratings have shown thermalstability up to 1000 C and would thus provide the temperature range along with theconstantsignalduringreactorirradiation.Inconclusion,forsilicaglassfibers,OSUfoundthatnormalSMF-28fiberhasatemperaturelimitofaround900Candaradiationfluenceofaround8x1017n/cm2.ForsilicafiberwithinscribedType-IIBragggratings, the temperature limitsarearound1000Candwehavenotfoundaradiationfluencehighenough(>2x1018n/cm2)todisruptsensinginthefiber.When combining temperature and radiation, SMF-28 fiber provides null data when thereactorisathighpower,whileBragggratingfiberprovidesasteadymeasurementsignal.

Inconjunctionwiththetesting,wehavealsofoundwaystoruggedizeandpackagethefibersensorforinstrumentationintotheTREATreactor.SapphireOpticalFiberForsapphirefibers,wehavemadesignificantprogressinmakingthesapphirefiberabletoproduce temperature measurements. Using sapphire fiber for sensing has been nearlyimpossible due to themultimodal nature of the fiber. The highlymultimodal nature ofsapphireisduetothelargecoresizeofthefiberandthelackofareflectivecladdinginthefiber. OSUhasinventedawaytocreateareflectivecladdinginsapphirefiber,whilealsoreducingthecoresizeofthefiber.Thisnewcladdingtechniquereducedthelightmodesinthe fiber, enabling the sapphire optical fiber to produce distributed temperaturemeasurements. Thisnewsapphirefiberwastestedtohightemperatures(1000C)andinradiationenvironmentsandshowedzerodegradationineither.OSU developed a method of creating a near single mode sapphire optical fiber whichenabledthesapphireopticalfibertoproducedistributedtemperaturemeasurementsusingthe OFDR sensing technique. With a singlemode sapphire fiber created, OSU inscribedBragggratingsevery6cmalongtheentirefibertoactashightemperaturesensors.Thesesapphire sensors were tested under the following environments: during heating in theabsenceofradiationupto1000°C,duringCo-60gammairradiationatroomtemperatureandfinallyduringreactorirradiationatroomtemperature.The sapphire Bragg grating sensorswere ramped to 1000 °C, in 100 °C steps, in a tubefurnace. The sapphire Bragg gratings were able to produce stable and accuratetemperature measurements at every temperature tested. The gratings showed zerodegradationinregardstotheirreflectedbackscatteramplitudetotemperaturesupto1000C. The sapphire Bragg grating sensors have great potential for producing accuratetemperature measurements at temperatures higher than a 1000 C, unfortunately, timerestrictionscausedareductioninthescopeofourtesting.TeststohighertemperaturesofthesapphireBragggratingsisrecommendedforfuturework.Following the high temperature tests, the cladded sapphire fiber with inscribedfemtosecond Bragg gratings was tested for its radiation survivability. The radiationsurvivability tests consisted of two tests: a gamma ray only irradiation and a reactorirradiation(neutronsandgammarays). TheOhioStateReactorLabwasusedforbothofthesetestsasthefacilitycontainsa450kWresearchreactorandaCo-60irradiator. ThesapphirefibersensorswereplacedintotheCo-60irradiatorandirradiatedforatotalof5fulldays.Thegammadoseoftheirradiatorisapproximately23.1kRadperhour.Overthe5 days of irradiation, the sapphire sensors accumulated approximately 2.82MRads. ThesapphireBragggratingswereunaffectedbythegammaraysastheirreflectiveamplitudenever changed over the course of the experiment and the gratings produced a constanttemperaturemeasurement.Following the irradiations in the gamma irradiator, the sapphire fiber sensors weretransferred into the Central Irradiation Facility (CIF) dry tube located in the Ohio State

ResearchReactor.TheCIFtubeisanopenairdrytubethatissituatedinthemiddleoftheOSURRcore. ThisexperimentoccurredduringtheOSUReactorLab’sbusyseasonandsounfortunately,we had reduced hours for 3 of the 4 days of irradiation.Nonetheless, thesapphire Bragg gratings appeared to have survived the irradiations in the OSURR andproducedreasonable temperaturemeasurements.ThesapphireBragggratingswereableto survive1GRadof gammadose andaneutron fluenceof1018n/cm2without showingdegradation of the gratings. The survivability testing of the sapphire sensors wassuccessfulbuttheaccuracyandprecisionofthesesensorsisrecommendedforfuturework.TaskIID,E,F:FabricateandcharacterizeHTTLSensorsfortestinginrodgeometryTheINLHTTLlabteamfabricatedandcharacterizedtheHTIRtemperaturemeasurementsensors(fourdevicesspecifically)andsentthemtotheUWfortestingintheout-of-pilecapsuleasplannedandhasdeliveredthethermalconductivityprobeandultrasonictemperature(UT)sensorthisyearforout-of-pileandin-piletesting.Alltheseinstrumentsaredescribedbelow.InanefforttodevelopadvancedfuelsforLWRsaswellastechnologydevelopmentforadvancedreactors,transienttestingisneededtodevelopanddemonstratethesafetybasisoftheseadvancedsystems.Compactsensorscapableofcollectingdataduringtransienttesting(e.g.,temperatures,thermalconductivity,etc.)weredevelopedinthisproject.Specifically,theHighTemperatureTestLaboratory(HTTL),locatedatIdahoNationalLaboratory(INL),developedandprovidedthreespecificinstrumentsforuseduringthisproject.Thethreeinstrumentsprovidedwerethermocouples,thermalconductivityprobesandultrasonictemperatureprobes.Thedevelopmentandconstructionofeachinstrumentisdiscussedbelow.Fourhigh-temperatureirradiation-resistantthermocouples(HTIR-TCs)wereprovidedtosupportin-piletestingconductedintheUniversityofWisconsinreactor.ThedesignandfabricationofHTIR-TCswascompletedatINLasshowninFigure1.Thedesignincorporatedfeaturestoaccommodatetestconditionsandgeometryforthein-pile testing. Specifically, INLequipmentwas configured to fabricateHTIR-TCs foruse intheexpectedtemperaturegradient.TheprimarytemperaturegradientfortheTCdecreasesfrom1500 °C to~100 °C in an18 inch length extending from theTC tip. Hafnia (HfO2)insulation was used in this 18inch region. The remainder of the metallic sheath wasinsulatedusingalumina[Al2O3].Heattreatmentwasachievedusingalargehorizontaltubefurnace. DuringheattreatmenttheTCtipwasheatedto1650°C. Calibrationto1550°CwascompletedinthesametubefurnaceusingaNIST-traceableTypeSTCasthereference.Unique geometry limitations required an innovative solution to ensure water-tightintegrity of the HTIR-TCs. A minimum metallic sheath length of 22 ft. was originallyspecifiedtoextendfromthetipoftheTCtoanacceptablepositionabovethereactortankwaterlevel.However,asinglemetallicsheathofsufficientlengthwasnotavailableandthepool-to-test pass-through could not accommodate a splice sleeve. For those reasons, adecisionwasmadetofabricatetheTCusingametallicsheathforthefirst12ft.Apottingcup was then designed to transition from the metallic sheath to soft extension cable –belowthewaterlevel.Toensurewater-tightintegrity,thepottingcupalsoincludedbarbs

for attaching aTygonPVC tube to the soft extension end of the cupwithout requiring aclamp. TheTygon tube,which contains the soft extension cable, extendswell above thewater level. (See Figure 1.) (Note that thewater-tight integrity of the potting cupwithTygontubewasverifiedinahydrostatictestoveraperiodexceeding2weeks.)

Figure1.HTIR-TCdesign.Pre-irradiationtestingconductedattheUW-MexposedcalibrationandconstructionprocessweaknessintheHTIR-TC.Temperatureerrorsinexcessof2%werefoundanditwassuspectedthatoxygenconcentrationlevelsof1ppmduringtheheattreatandcalibrationprocessesmayhavecontributedtothiserror.TheTCsweresentbacktoINLforre-heattreatandcalibration.Changesweremadetothecalibrationandheattreatmentprocessthatdrasticallyreducedoxygenconcentrationlevels(1x10-15ppm).Figure2showstwoniobiumtubesthatweresubjectedtoheattreatmentprocesses.Thetoptubewasheattreatedusingtheoldprocesswhiletobottomwasheattreatedusingthenewprocess.Afterheattreatmenteachtubewassubjectedtoabendingtest.Thetoptubefailedwithabrittlefracturewhilethebottomtubewasfoundtomaintainitsductility.ApronouncedbenefitofthischangeisthatHTIR-TCcannowbemanufacturedtobeductile.Thisgreatlyenhances

installationoffutureHTIR-TCs,makingitpossibletoinstallitintesttrainsthatrequirebendingofthethermocouple.

Figure2.BendingofNiobiumsheath(top)subjectedtoheattreatmentprocessat(1ppm

O2)andNiobiumsheath(bottom)subjectedtoimprovedheattreatmentprocess.Twotransienthotwiremethod(THWM)thermalconductivityprobeswerealsoconstructedatINL(SeeFigures3and4).Theprobesarecapableofmeasuringthermalconductivityupto1100°C.The1100°CratingisbasedontheuseofatypeKthermocoupleintheheatedsectionoftheprobe.Thefirst100mmoftheextensionsectioniscapableofwithstandingtemperaturesupto800°C.Thislimitwasestablishedthroughperformancetestingoftheheaterextensionwireweld.Nondestructiveevaluationsoftheweldswerealsoperformedusing3Dcomputedtomography.

Figure3.SchematicoftheTHWMthermalconductivityprobe.

Figure4.PhotoofPrototype1withpennyforopticalscale.Inadditiontotheweldevaluations,3Dcomputedtomographywasusedtoevaluateotherportionsoftheprobes.Figure5showsacutawayimageofprototypeprobe3fortheareabetweenA-AandB-BshowninFigure1.Computedtomographyfoundcontactbetweenthesensewireandtheheaterextensioninalloftheprobesscanned,seeFigure6.Thelengthofcontactcanbeasmuchas30mm.Thiscontactregioncanaffectthepowerdistributioninthe probe. To accommodate for the contact, a correction factor was applied to themathematicalmodel.

Figure5.Computedtomographyscanofprototypeprobe3.

Figure6.Computedtomographyscanofprototypeprobe3showingthecontactbetween

thesensewireandtheheaterextensionwire.Prototypeprobe3was tested in fused silica at20°Cand250°C. Figure7 showsProbe3insertedinthefusedsilica(b)whichwastheninsertedinthefurnace(a).Figure8isaplotof the thermal response of Probe 3. An input power of 4Wwith an initial steady statetemperatureof~240°Cwasused.Usingthemathematicalmodelwiththecorrectionfactorandthedatafromthistest,thecalculatedthermalconductivityshowedgoodagreement(<8%error)withpublisheddata.

(a)

(b)Figure7.Performancetestingoftheprobeat250°C.

Figure5.Thermalresponseofprototypeprobe3infusedsilicawithaninitialsteadystate

temperatureof~240°C.Aspartofthisproject,anewcontrolandanalysissoftwarepackageprovidedbytheFrenchAtomicEnergyCommission(CEA)wasimplemented.Figure8showsascreencaptureoftheanalysisinterface.Thisnewsoftwareprovidedenhancedpowercontrolandatimesavinguserinterface.ConstructionandtestingoftheTHWMthermalconductivityprobewascompletedatINLanddeliveredtotheUW-M.Trainingonthesystemwasalsoprovided.Figure9showsthecomponentsdeliveredtotheUWandisstillbeingtested.

Figure8.ScreenshotofthetestusingCEAsoftwarewithfusedsilicaat20°C.

Figure9.ThermalconductivityprobecomponentsdeliveredtoUW-M.Threeultrasonicthermometers(UTs)wereconstructedatIdahoNationalLaboratory(INL)anddeliveredtoUW-Malongwithapulser/receiversystem.Trainingwasalsoprovided.AschematicofatypicalUTisprovidedinFigure10.

Figure10.Typicalrepresentationofanultrasonicthermometer.TheUT construction process is relatively complicated. Figure 11 shows aUT at severalstepsinthefabricationprocess.

Figure11.FabricationstepsandelectronicequipmentforUltrasonicThermometer.

Three differentUTswere constructed. TheUTs delivered are identified asMolybdenum,Inconel and InconelMulti-Segment. The InconelMulti-Segment contained 4 temperaturesensingsegmentswhiletheothertwocontainedonlyone.Duringthecalibrationprocess,themaximumtemperaturewasestablishedduetosignalattenuation.Table1givessensortemperaturelimits.Figure12presentsthenormalizedcalibrationdataforeachsensor.Thecalibration data was found to be acceptable, with the exception of the Inconel Multi-

Segment 3. Poor calibration was the result of low signal amplitude caused by amanufacturingflaw.UWsuccessfullytestedtheseinout-of-pileandin-pileexperiments.Table1.Sensortemperaturelimitsestablishedduringcalibration.

Sensor

Configuration

MaximumTemperature

Molybdenum

Singletemperaturesensor

1500°C

Inconel

Singletemperaturesensor

900°C

InconelMulti-Segment

Fourtemperaturesensors

900°C

Figure12.NormalizedcalibrationdatafortheUTs.

Summary:FourHTIR-TCs, twoTHWMthermalconductivityprobesandthreeUTswereprovidedtosupport in-pile testing conducted in the University of Wisconsin reactor. A pronouncedbenefitofthisprojectisthatHTIR-TCscannowbemanufacturedtobeductile.ThisgreatlyenhancesinstallationandfutureuseofHTIR-TCs,makingitpossibletoinstallthemintesttrainsthatrequirebendingofthethermocouple.AnotherbenefitresultingfromthisprojectisthenewcontrolandanalysissoftwarepackageprovidedbyCEAfortheTHWMthermalconductivityprobe.Thisnewsoftwareprovidesenhancedpowercontrolandatimesaving

user interface. Finally, this project provided advancements in the development of UTsensorswithnewmaterialchoicescapableofmeasuringtemperaturesto1500°C.TaskIIIandIVarecoveredinthetestingprogramforthesensorsasnotedabove:Bothout-of-pileandin-pileexperimentswerecompleted.AdetailedreportofthisworkhasbeenuploadedtoourPICSwebsite.Thisworkprovidesademonstrationbyexperimentandsupportinganalysisofthecapacityofseveraladvancedtemperaturesensortomakelocaltemperature measurements during transients in a radiation environments, as would befound in a light water nuclear reactor environment. This work has also quantitativelycharacterized several specifications of the sensors, such as precision and accuracy oftemperaturemeasurements,measurementofthetimeresponseforthesensor,effectofthefiber sheath used on the sensor, and theminimumneutron fluence values for sustainedsensorfunctionality.The testingof thearrayofsensors iscomplimentedwith the in-depth investigations intothe chief causes of limitation and failure of the fiber optic sensor and subsequentimprovements to the sensor design. The currently available set of local temperaturesensing instrumentation brings with it limitations that are a major hindrance to thedevelopment and potential of advanced reactor designs. From the inability of hightemperatureRTDstobedeployedinahighradiationenvironmenttothepoortemperaturemaxima of 1200oC for radiation hard thermocouples to the cripplingly low spatialresolutionofbothtypes,advancedsensorsareamuchneededdevelopmenttosupportthegrowthandprogresstobemadeinmanyotherareasofthenuclearindustry.

The fiber optic distributed temperature sensor has proven resilient in radiationenvironments,functioningwithstandarddeviationsunder3oCregardlessofradiationfluxsizeortotalfluencereceived.Thoughsufferingfromaslightlylowerprecisioncomparedtoothertemperaturesensors,thefibersensorofferstheincrediblyhighspatialresolutionofa0.64mmsensorspacingandtotalsensing lengths inexcessof tensofmeters.This thesishasdemonstratedthevalueofvariousaspectsoffabricationconcerningthefibersensors(heattreatments,steelsheaths,inertgaseousenvironments,etc.)aswellassuggestionsforthebettermethods to employwhen implementing them.Thisworkpresents thedata tosupportthetheorythathydrogenisthemainchemicalagentresponsiblefordegradationofthe fiber’s ability to transmit light both at high temperatures and in radiationenvironments.Italsoshowstheefficaciousnatureofthesolutionsprovidedtocombatthismodeofsensor failure.By incorporatingthe inertsheathandremovingthe fibercoating,hydrogen-caused attenuation of the fiber signal is limited to less than 2 dB/m for allcombinedhigh temperature and radiation induced effects.Measurement of the temporalimpactthesheathandcovergashasonthesensorismeasuredtobe0.237secondsandthepositiveproofof the fibersensor’sabilityto function insideofanuclearresearchreactorwithoutsignsofdeteriorationisdefinitivelydisplayedattemperaturesupto900oC.

ThesensorsfromourINLHTTLteamshowedpromisingresults.TheHTIR-TCperformedwellbothinandoutofradiationenvironmentsshowingnoobservabledrift,impairmentofprecision,or signal lossasa resultof irradiation. It alwaysmaintainedamarginoferrorbelow2%thoughwas found tobehighlysensitive toeven theslightest tracesofoxygen

(showing severe signal drift for O2 levels as low as 1ppm). The HTIR- TC also has acalibration issue,whichmay result in an offset in the accuracy of its readings stemmingfromanunidentifiedcause.TheUTsensorsdidnotperformaswellinthattheonlyoneofthe three sensors which functioned properly had standard deviations from ±14.3oC attemperatures above 400oC but dropping to ±35.56oC for the broader 0-850oC range. Thetotalfailureofthehightemperaturemolybdenumsensorasaresultofinternalmechanicalinterference fromfabricationerrormakesclear theneed to improveupontheprocessofinsulatingthewaveguidewire.Similarly,thelackofapropertransformationequationforthe otherwise seemingly functionalmulti-segment Inconel sensor indicates an additionalneed for standardization of the calibration process and improvement in data acquisitionsoftware.Nevertheless, thesingle-segmentInconelUTdidshowitscapacitytoaccuratelymeasurelocaltemperaturesthroughatemperaturetransientupto850oC.

Allofthesesensorshavehadtheirtheoreticaltemperaturesensingcapabilitiesvalidatedsothat thenext steps tobe takenareas imminentas theyare important.Opportunities forimprovingourunderstandingofthefibersensorsparticularlyincludeanadvancedstudyofthe impact that the termination has on the fiber sensor and then how to optimize theaddition of that component. Another topic regarding the futurework of the fibers is theimpact that keying the fibers at an elevated temperature may have on the measurabletemperature range. Both of these are topics about which little is well documented butwhichmayhaveasubstantialinfluenceonthefunctionalityofthefibers.

Regarding the HTIR-TC, further investigation is needed into the cause(s) of the offsetsometimesobservedinthesensors.Testingthesensortohigherandhighertemperaturesuntil failure to discover the true maximum temperature the HTIR-TC can withstand isanotherworthwhilecourseofstudy.Finally,theUTsensorsdesperatelyneeddevelopmentof data acquisition and processing software. Currently, the data is simply read from anoscilloscopeandallpost-processingmustbedonemanually.Thisismostlyahindranceintheefficientuseoftimeandsoinhibitstheamountoftestingwiththesensorthatcanbeeffectivelycompleted.This improvement isnecessary to facilitatedtesting thatwillallowustounderstandhowtheUTbehavesunderconditionslikethermaltransientsandotherdynamicprocesses.

TaskV:DesignofaTransientReactorTestwithAdvancedInstrumentation:Wehavedevelopedwhitepapers,thesesandshortresearchpaperstodescribeourdevelopmentsforuseintheTREATandothertransientandsteadystatetestprograms.ThesehavebeenuploadedtoourPICSwebsiteforDOEuseasappropriate.

COSTSTATUS:TheIRPcontractwasdelayedinitplacementatUW-Madisonbytwomonths.Inaddition,thesubcontractstoIdahoState,KansasStateandOhioStateweredelayeduntilJanuary2015.Thusexpenditureshavelagged.Asoftheendofcalendaryear2017wehaveexpended96%ofobligatedfunds.FinalexpendituresbyouruniversityteamarebeingSCHEDULESTATUS:Therearenosignificantchangesintheschedule(seebelow) Task IA: Hodoscope Technology Enhancements Task IA – 1: Collimator-based Hodoscope design, enhanced data-acquisition detector arrays Task IA – 2: Cloud-chamber testing at ISU and based on results concept is not feasible Task IA – 3: Modified Hornyak button concept that uses optical fibers for more light collection

Task Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Task IA-1 Task IA-2 Task IA-3 Quarterly, Annual, and Final Reports

Task IB: High-Efficiency Neutron Detector Array Task IB – 1: Design of the HENDA for use in the KSU TRIGA beamport Task IB – 2: Fabricate HENDA and test with fuel pin motion in TRIGA Task IB – 3: Efforts moved to MPFD work for out-of-pile and in-pile testing (Task IIA)

Task Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Task IB-1 Task IB-2 Task IB-3 Quarterly, Annual, and Final Reports

Task IIA: Micro-pocket Fission Detectors Task IIA – 1: High-temperature testing of MPFD at HTTL out-of-pile facility Task IIA – 2: Optimize MPFD design for in-pile testing in KSU TRIGA reactor Task IIA – 3: Continue to test MPFD in KSU TRIGA in collaboration with UW

Task Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Task IIA-1 Task IIA-2 Task IIA-3 Quarterly, Annual, and Final Reports

Task IIB: Diamond Diode Temperature Sensor Task IIB – 1: Fabrication & Characterization of diamond sensor for fuel rod application Task IIB – 2: Out-of-Pile testing of diamond temperature sensor (revised thermistor design) Task IIB – 3: In-pile testing of diamond temperature sensor in UW TRIGA reactor

Task Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Task IIB-1 Task IIB-2 Task IIB-3 Quarterly, Annual, and Final Reports

Task IIC: Fiber Optic Temperature Sensors Task IIC – 1: Fabrication and calibration of fiber optic sensor Task IIC – 2: Out-of-Pile testing of fiber optic sensor Task IIC – 3: In-pile testing of fiber optic sensor in UW TRIGA reactor

Task Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Task IIC-1 Task IIC-2 Task IIC-3 Quarterly, Annual, and Final Reports

Task IID: HTIR-TC Fabrication for testing (Yr 1) and in-pile transient testing (Yr 2-3) Task IIE: Ultrasonic Thermometer Fabrication, out-of-pile and in-pile transient testing Task IIF: THWM-NP Fabrication for out of pile and in-pile transient testing

Task Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Task IID: Task IIE: Task IIF: Quarterly, Annual, and Final Reports

TaskIIIandIVarecoveredinthetestingprogramforthesensorsasnotedabove: Out-of-pileTesting:TaskIA-2,TasksIIB-2andIIC-2,TaskIID,TaskII-E,TaskIIF In-pileTesting:TasksIA-3andIB-2,3,TasksIIA-3,IIB-3,IIC-3,II-D,II-E,II-FTaskV:DesignofaTransientReactorTestwithAdvancedInstrumentation:Tobegininthefirstyearoftheprojectwithinputfromouradvisorycommitteegroupontestingneeds.Designofthetransienttestwillbeaccomplishedattheendofthefinalyear.

CHANGESINSCOPE:Therehavebeennochangesinscope.PROBLEMSENCOUNTERED:Therehavebeennomajorproblemsordelaysencountered.PERSONNELandCHANGES:Prof.JeremyRobertshasassumedCo-PIroleatKSU.ISUPersonnel: GeorgeImel,PI;

Students:HarishchandraAryal;CodyWomak

KSUPersonnel: JeremyRoberts,PI;D.McGregor,M.Harrison,Co-PIsStudents:D.Nichols,R.Ghosh,W.Fu

OSUPersonnel: TomBlue,PI,Students:B.Wilson,K.McCary,R.Palmer

UWPersonnel: M.Corradini,PI;M.Anderson,Co-PI,PaulBrooks,Students:J.Bredemann,T.Kim

INLPersonnel: KurtDavis(PI),JoshDaw,TroyUnruh(D.Knudson–retired)RESEARCHPRODUCTS:Patents:3patentdisclosure(KSU,OSU,UW)ReviewedPublications:Published/AcceptedA.Birri,KellyMcCary,BrandonWilson,ThomasE.Blue,"ThermallyInducedBendLossAnalysisforDistributedOpticalSensinginNuclearReactors",TransactionsoftheAmericanNuclearSociety117(2017)JohnC.Boyington,RichardL.Reed,RyanM.Ullrich,JeremyA.Roberts.“Gamma-RayandThermal-NeutronFilterDesignforaTRIGAPenetratingBeamPort.”TransactionsoftheAmericanNuclearSociety,117.1162—1165(2017)J.Daw,etal.,“UltrasonicTransducerIrradiationTestResults,”10thInternationalTopicalMeetingonNuclearPlantInstrumentation,Control,andHumanMachineInterfaceTechnologies(NPIC&HMIT2017),SanFrancisco,CA,June11-15,2017.J.Daw,etal.,“UpdateonUltrasonicThermometryDevelopmentatIdahoNationalLaboratory,”10thInternationalTopicalMeetingonNuclearPlantInstrumentation,Control,andHumanMachineInterfaceTechnologies(NPIC&HMIT2017),SanFrancisco,CA,June11-15,2017.

M.J.Harrison,MichaelA.Reichenberger,DanielM.Nichols,DouglasS.McGregor,JeremyA.Roberts.“PreliminaryAnalysisofDamagetoMPFDsCausedbyReactorPulses.”TransactionsoftheAmericanNuclearSociety.116.(2017)P.Ghosh,WenkaiFu,RyanFronk,DouglasS.McGregor,JeremyA.Roberts.“EvaluationofMSNDsforFast-NeutronDetectionandtheTREATHodoscope.”TransactionsoftheAmericanNuclearSociety.115.109—112(2016)T.J.Kim,M.Anderson,Z.Ma,M.Corradini,“"HighTemperatureDiamondThermistorforNuclearReactor”,TransactionsoftheAmericanNuclearSociety116(2017)D.M.Nichols,MichaelA.Reichenberger,SarahStevenson,TannerSwope,CadenHilger,JeremyA.Roberts,NathanielEdwards,DouglasS.McGregor.“CharacterizationofArgon,P-10,andNeonIonizationGasesforUseinModularMicro-PocketFissionDetectorArrays.”InternationalConferenceonAdvancementsinNuclearInstrumentationMeasurementMethodsandtheirApplications,Liege,Belgium,June19—23(2017)R.K.Palmer,KellyM.McCary,ThomasE.Blue,"TimeConstantsforOpticalFiberTemperatureSensingusingaThermalResistanceApproach",TransactionsoftheAmericanNuclearSociety115(2016).R.K.Palmer,K.M.McCaryandT.E.Blue,"AnAnalyticalModelfortheTimeConstantsofOpticalFiberTemperatureSensing,"inIEEESensorsJournal,vol.17,no.17,pp.5492-5502,Sept.1,12017.R.K.Palmer,KellyM.McCary,ThomasE.Blue,"TimeConstantsforOpticalFiberTemperatureSensingusingaThermalResistanceApproach",TransactionsoftheAmericanNuclearSociety115(2016).V.K.Patel,MichaelA.Reichenberger,JeremyA.Roberts,TroyC.Unruh,DouglasS.McGregor.“SimulatedPerformanceofMicro-PocketFissionDetectors(MPFDs)intheTransientREActorTest(TREAT)FacilityusingMCNP6.”AnnalsofNuclearEnergy.104.191—196(2017)M.A.Reichenberger,TroyC.Unruh,PhilipB.Ugorowski,TakashiIto,JeremyA.Roberts,SarahR.Stevenson,DanielM.Nichols,DouglasS.McGregor.“Micro-PocketFissionDetectors(MPFDs)forIn-CoreNeutronDetection.”AnnalsofNuclearEnergy.87.318—323(2016)M.A.Reichenberger,JeffreyA.Geuther,DanielM.Nichols,TimothyJ.Sobering,JeremyA.Roberts,PhilipB.Ugorowski,DouglasS.McGregor.“ElectronicSupportSystemEnhancementsforMicro-PocketFissionDetectors(MPFDs).”ProceedingsoftheIEEENuclearScienceSymposiumandMedicalImagingConference,Seattle,WA,November8—14(2016)

M.A.Reichenberger,DanielM.Nichols,SarahStevenson,TannerSwope,CadenHilger,JeremyA.Roberts,TroyUnruh,DouglasS.McGregor.“FabricationandTestingofaModularMicroPocketFissionDetectorInstrumentationSystemforNuclearTest,Research,andTrainingReactors.”InternationalConferenceonAdvancementsinNuclearInstrumentationMeasurementMethodsandtheirApplications,Liege,Belgium,June19—23(2017)J.A.Roberts,MarkHarrison,WenkaiFu,PriyarshiniGhosh,DouglasS.McGregor,“StatusofFast-NeutronDetectorDevelopmentatKSUfortheTREATHodoscope.”InIRRMA10.Chicago,IL,July9—13(2017)B.A.Wilson,TonyBirri,ThomasE.Blue,"EvaluationofOpticalFiberBraggGratingsinaNuclearReactor"TransactionsoftheAmericanNuclearSociety116(2017)B.A.Wilson,KellyM.McCary,ThomasE.Blue,"OptimizationofSilicaOpticalFiberforHighTemperature,RadiationEnvironments",TransactionsoftheAmericanNuclearSociety116(2017)TobePublished/SubmittedA.Birri,KellyMcCary,BrandonWilson,ThomasE.Blue,"ThermallyInducedBendLossofSilicaOpticalFiber",IEEESensorsJournal,tobepublishedW.Fu,P.Ghosh,M.J.Harrison,D.S.McGregor,J.A.Roberts.“AGeant4EvaluationoftheHornyakButtonandTwoConceptualZnS(Ag)-BasedDetectorsfortheTREATHodoscope.”NIMA.tobepublishedW.Fu,P.Ghosh,M.J.Harrison,D.S.McGregor,J.A.Roberts.“Geant4andMCNP6EvaluationsofFastSensitiveMicrostructuredSemiconductorNeutronDetectorsfortheTREATHodoscope.”NIMA.M.J.Harrison,D.S.McGregor,J.A.Roberts.“RadiationHardnessofSiliconPhotomultipliersinFast-NeutronApplications.”NIMA.tobepublishedT.J.Kim,K.Davis,M.Anderson,Z.Ma,M.Corradini,“"HighTemperatureDiamondThermistorforNuclearReactor”,ReviewofScientificInstruments,submitted2017R.S. Skifton, Palmer, A. J., Calderoni, P., “The Development of Calibration Procedures forHigh Temperature Irradiation Resistant Thermocouples,” Instrumentation Science andTechnology,2017[accepted,inpreparation]B.A.WilsonandThomasE.Blue,"CreationofanInternalCladdinginSapphireOpticalFiberEnabling It to Produce Distributed Temperature Measurements by Optical FrequencyDomainReflectometry",IEEESensorsJournal,tobepublished

B.A. Wilson, Thomas E. Blue, "Effect of Gamma-Ray and Neutron Heating as InterferingInput for the Measurement of Temperature Using Optical Fiber Sensor System", IEEESensorsJournal,tobepublishedB.A.Wilson,ChristianM.Petrie,ThomasE.Blue,"HighTemperatureEffectsontheLightTransmissionthroughSapphireOpticalFiber",JournaloftheAmericanCeramicSociety,tobepublishedINLReportRichard Skifton, Joe Palmer, Brian Jaques, Pattrick Calderoni and Troy Unruh.,“PerformancereviewofHighTemperatureIrradiationResistantThermocouples(HTIR-TC)inOut-of-pileandIn-pileTests,”INL/INT-17-43511,September2017.

Theses

J.Bredemann,“AdvancedTemperatureSensorsforLocalMeasurementsduringTransientsinaRadiationEnvironment”,M.S.Thesis,UniversityofWisconsin-Madison,December2017

S.Mikael,“CarbonMaterialGrowth,CharacterizationandDeviceFabrication”,Ph.D.Thesis,UniversityofWisconsin–Madison,January2016B.Wilson,"EvaluationofOpticalFiberSensorsinHighTemperatureandNuclearReactorEnvironments"Ph.D.Thesis,TheOhioStateUniversity,Columbus,OH,2017C.A.Womack,“TheConstructionandCharacterizationofaLargeVolumeWilsonCloudChamberUtilizingOrthogonalCamerasforImageCapture”,M.S.Thesis,IdahoStateUniversity,December2015IRPWebsite:https://sites.google.com/a/wisc.edu/treat-restart-project/home