2013–2023 年 II 期与 III 期临床试验终止情况分析 Analysis of phase II and phase III clinical trial terminations from 2013 to 2023

WHENTRUSTMATTERS

DNV

MARITIMENUCLEARPROPULSION

Technologies,commercialviability,andregulatorychallengesfornuclear-poweredvessels

WHITEPAPER

Maritimenuclearpropulsion

Contents

Foreword3

Executivesummary4

1

.Introduction

6

2

.Civilianmaritimenuclearpropulsion:Backagain?

8

2.1Themaritimenuclearfuelcycle–inperspective9

2.2Arenon-civilianmarinenuclearvesselsrelevant?13

3

.Civiliannuclearpropulsiontechnologyreadiness14

3.1Whatarethepreferredproperties?15

3.2Candidatetechnologiesandprojects17

4

.Internationalandnationalagreementsandregulations20

4.1Existingregulatoryframeworks23

4.2Regulatoryroadmaps–themaritime-nuclearregulatorynexus24

5.Businessmodelsandcosts28

5.1Howtooperatemaritimenuclearinstallations?30

5.2Whatdoesnuclearpropulsioncost?31

6.Simulatingnuclearpropulsioninmerchantshipping36

Annex:Investmentassumptionsfornuclearandconventionalvessels40

Listofabbreviations42

References43

Projectteam

Disclaimer

Independence,impartiality,andadvisorylimitations

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ThisreportisgeneratedbyDNVinitsadvisorycapacity,subsequenttocon-

flict-of-interestassessments.ItisseparatefromDNV’sresponsibilitiesasathird-

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ThecontentinthisdocumentwillnotobligateorinfluenceDNV’sindependentandimpartialjudgementinanyfuturethird-partyassuranceactivitieswithDNV.

Compliancereview

DNV’scompliancewithethicalandindustrystandardsintheseparationofDNV’srolesissubjecttoperiodicexternalreviews.

2

OleChristenReistad,EirikOvrum,ErikStensrud,AnneSophieSagbakkenNess

Photocredits:

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Authors

Maritimenuclearpropulsion

FOREWORD

Asthedrivefordecarbonizationbecomesmoreurgent,theworldstandsinneedofsolutionsthatcanmeetthemoment.Thisextendstoshipping–anindustrywhich

providesthebackbonetoworldtradebutwhereambi-tiousdecarbonizationtargetshavebeensetandincreas-inglyproactiveregulationsarebeingimplemented.

Decarbonizationisnolongeradistantambitionbutan

immediatenecessity,anobligation,andaformallyagreedobjective.Everyviablepathwaymust,therefore,be

carefullyconsidered,includingthosepreviouslydeemedimprobable.

Nuclearpropulsion,onceregardedasadistantprospect,isnowunderactiveconsiderationasarealoptionforthecommercialmaritimefleet.Shipyardsandshipowners

areexploringitspotentialandweighingthepromiseofvirtuallyemission-freepoweragainstthecomplexityofintroducingsuchatransformativetechnologyintocom-mercialfleets.

Thistechnologycarriesinherentrisks.Itsacceptance

willdependnotonlyontechnicalperformancebutalsoontheconfidenceofthepublicitserves.Inthiscontext,independentandcompetentassurancebecomesindis-pensable.Itisthemechanismbywhichrisksareman-

aged,trustisbuilt,andcredibilityisearned.Assuranceisnotsimplyasafeguard–itisanenablerofprogress.

Themaritimesectorbenefitsfromalong-established

systemofclassificationsocietiesthatharmonizetechnicalrules,provideindependentverification,andbridgethe

gapbetweenregulationandoperation.Thisframework

enablesthedevelopmentandassessmentofnewtechnol-ogies,includingnuclearpropulsion,withinacoherentandinternationallyrecognizedassurancestructure.

Nocomparablesystemexistsintheland-basednuclearsectors,whereregulatoryresponsibilitiesarefragmentedandprimarilynationallydefined.Theexperienceand

institutionalframeworksofthemaritimeclassification

systemthereforeofferauniquefoundationforenablingciviliannuclearpropulsion–creatingamodelofharmo-nizedoversightthatcouldinspirebroaderapproachestoinnovationinotherhigh-risk,high-valuetechnologies.

Thisreportexploresthetechnologies,commercialvia-

bility,andregulatorychallengesthatframethefutureof

nuclearpropulsion.Itseekstoprovideclarityinacomplexfieldandtosupportinformeddecisionsonwhether,andhow,thisoptioncanplayaresponsibleroleinshapingthefutureofmaritimetransport.

Asthemaritimeindustrynavigatesthecomplexitiesof

decarbonization,nuclearpropulsionpresentsbotha

formidablechallengeandatransformativeopportunity.

Whetherthistechnologybecomesacornerstoneoffuturefleetswilldependonourcollectiveabilitytomanageitsrisks,earnpublictrust,andestablishrobustassurance

frameworks.

Thisreportaimstoequipstakeholderswiththeinsightsneededtoevaluatethisoptionresponsibly,toinnovate

withintegrity,andtoshapeasustainablefutureforglobalshipping.

OleChristenReistad

SeniorPrincipalResearcher

DNV

3

Maritimenuclearpropulsion

4

EXECUTIVESUMMARY

Astheshippingindustryfacesmountingfinancialand

regulatorypressurestodecarbonize,nuclearpropulsionisincreasinglyviewedasapotentialsolution,offeringthepromiseofstable,predictableenergycosts,enhanced

operationalflexibility,andreducedrelianceontraditionalbunkeringinfrastructure.

Whilenocivilianmaritimenuclearfacilitieshavebeen

commissionedinoverfourdecades,shiftingenvironmen-tal,technological,regulatory,andcommercialdynamicsarereignitinginterestsandhighlightingthetransforma-tiverolethatnuclearpowercouldplayinthemaritime

industryoverthecomingdecades.Thiswhitepaper

describesthecurrentstateofplayofnuclearmaritimepropulsionandemphasizestheneedfortechnologicalinnovation,regulatoryclarity,andeconomicfeasibility.

Althoughnuclearpropulsionanditssupportinginfra-

structurearenotyetcommerciallyviable,pastoperatingexperienceoffersvaluableinsightsforthepathahead.

Almostallpreviouscommercialprojects–vesselssuchasSavannah,OttoHahn,andMutsu–operatedusingpres-surizedwaterreactors(PWRs),whichrequiredextensivemonitoringandactivesafetysystemstomanagetran-

sients.Thisreactortypetypicallydemandsalarge,highlyskilledcrew,increasingoperationalcostsandposing

commercialchallengesforshipowners.

Manymilitaryvesselshavealsobeendeployedwith

nuclearpropulsiontechnology.However,theirrelevancetofuturecommercialprojectsisconsideredlimited,duetothedifferingtechnologicalandcommercialrealitiesofthesevessels.

Withtheseconsiderationsinmind,thiswhitepaper

outlinesthepreferredcharacteristicsofreactorconceptscurrentlybeingdevelopedformarineuse.Allmaritime

nucleartechnologieswilldifferfromland-basedequiv-

alentsduetosomekeycharacteristics,suchasmobility,exposuretoharshseaconditions,andoperationalprofile.Further,maritimeinstallationswillvarysignificantly

dependingontheirpurpose–propulsion(nuclear-pow-eredships,NPSs)orpowergeneration(floatingnuclearpowerplants,FNPPs.

Designchoicessuchassingleversusdualreactorsinvolvetrade-offsbetweencost,space,reliability,andpower

availability.Smaller,standardizedreactorsmayoffer

advantagesformerchantshipping,especiallyifthey

featurepassivesafetysystemsandminimalcrewrequire-ments.Low-pressuresystemsandGenerationIVorheat-pipereactorscouldbepreferredfortheirinherentsafetyandreducedcomplexitycomparedtotraditionalPWRs.

Marinereactorsmustbecompactanddesignedfor

infrequentrefuelling–ideallyalignedwithotherrequiredmaintenanceactivitiessuchasdry-dockingtominimize

impactsonshipavailability.Refuellinglogisticsarecon-finedtospecializedports,andglobalnuclearfuelsupplychainsfacepressureduetogeopoliticalshifts.Thereac-tor’spurpose–mechanicalpropulsionorelectricpower–determinesthesystemconfiguration,withsteamturbinesornuclear-electricsetupsofferingdifferentbenefits.

Higherfuelenrichmentlevelsmaybenecessarytomeetoperationaldemands,andonlinerefuellingcouldreshapecurrentlimitations.

Ultimately,reactortechnologyselectionhingesonbalanc-ingsafety,efficiency,andoperationalfeasibility.Severalprojectsindifferentcountriesarealreadyunderwaywithdifferingapproachestofuel,coolant,andsafety.

Translatingtheseconceptsintocommercialrealityrequiresmorethantechnicalinnovation,however.

Acost-effectiveandprovennuclearfuelcycle,tailored

formaritimeuse,mustbedevelopedbytheindustry.Thisincludesestablishingclearlydefinedrolesandresponsi-bilitiesacrossthesupplychain,fromfuelproductionandreactorintegrationtoloading,exchange,anddisposal.

Crucially,storageanddisposalofspentnuclearfuelarefundamentaltothefunctionalityandcredibilityofthe

supplychain.Reactordesignandfueltypewilldirectlyinfluencetheserequirements,andthesefactorsmust

beaddressedbeforeanyoperatinglicenseisgranted.Aspartofthis,provisionsforthewholemaritimefuel

cycle–includinglong-termwastemanagement–are

essential,notonlyforregulatorycompliancebutalsoforadvancingpublicacceptance.

Astechnologyandsupplychainsevolve,theymustberigorouslytestedundermaritimeconditions.Duetothehigh-riskpotentialandtheneedforpublicacceptance,thisincludesverificationandassurancesofmajorcom-

Maritimenuclearpropulsion

5

ponents,suchasreactorsystems,fuellogistics,andportinfrastructuretoensuresafeandefficientinstallation,

operation,andmaintenanceatsea.

Thedevelopmentofacommercialmaritimenuclearindus-tryalsoneedstobesupportedbyapredictableandinter-nationallyacceptedregulatoryframework.OrganizationssuchastheIMOandIAEAmustleadeffortstoestablish

standardsforfuelmanagement,shipconstruction,and

operationalprotocols.Classificationsocietieswillplayacriticalroleinenablingglobaladoption,helpingtoover-comethefragmentednatureoftheland-basednuclear

industryandfosteringastandardizedmaritimeapproach.

Theregulatorylandscapefornuclearshippingwilllikely

exceedwhatthemaritimeindustryisaccustomedto,

openingthedoortomultiplefuturesystemconfigura-

tions.Byidentifyingkeyactors,theirmandates,andthe

needforcoordination,regulatoryroadmapsoutlinedin

thiswhitepaperofferessentialguidance.Asrolesmulti-ply,clarifyinginterfacesbecomesincreasinglyimportant–somethingtheseroadmapshelpaddressbymappingkeyinterdependencies.

Safety,securityandnon-proliferationremainparamount.Futureinstallationsmustbedesignedtowithstandcolli-sions,groundings,andexternalthreatssuchassabotageorpiracy.Remotemonitoringandadvancedcommuni-cationcapabilitieswillbeessential,alongwithrigorouscybersecuritymeasures.

Technologicaladvancements,particularlyindigitalization–encompassingautomationandcommunication–are

helpingtoovercomelongstandingchallenges.These

innovationsmayenhancesafety,reducecosts,andsup-porttransparentmonitoringandcybersecurity,factorswhichareallcriticalforbothpublicconfidenceandinter-nationaloversight.

Thesuccessoffuturemaritimenuclearinstallationswillalsodependonthedevelopmentofcompellingbusinessmodels.Thesemustreflectthecommercialrealitiesof

shippingandprovideaclearunderstandingoftotalcostofownership,especiallyacrosstheentirefuelcycle.

Cost-competitivenesscouldbesignificantlyenhanced

throughmodularandstandardizedapproaches,which

streamlineconstruction,simplifymaintenance,provide

independentassurance,andfacilitateregulatoryapprovalacrossjurisdictions.

Progressisbeingmade.TheintegrationofGenerationIII+andIVreactortechnologies,alongwiththeriseofsmall

modularreactors(SMRs),mayenableshorterconstruc-

tiontimes,greaterstandardization,andimprovedsafety.Thesedevelopmentsmayalsosupportreducedcrew

requirementsandoperationalefficiencies,strengtheningthebusinesscasefornuclearpropulsion.

Reactorcostsareakeyfactor.DNVcasestudiespre-

sentedinthispapershowthatnuclearcanoutperform

othertechnologiesunderbothlowandhighfuelprice

scenarios.AreactorcostbelowUSD18,000/kWcouldbecompetitiveiffulldecarbonizationisachievedby2050,whilecostsbelowUSD8,000/kWcouldbeviableeven

withoutfulldecarbonization.

Realizingthepotentialofnuclearpropulsioninmaritimerequiresmorethantechnologicalreadiness.Itdemandscoordinatedglobalaction,involvingawiderangeof

actorsacrossthemaritimeindustry,regulators,andsoci-etyingeneral.

Withstrategicinvestmentandinternationalcollabora-

tion,nuclearenergycouldbecomeacornerstoneofthemaritimeenergytransition,deliveringsafe,efficient,andzero-emissionpropulsionfortheglobalfleet.

FIGURE0-1

Transferofheatfornuclearreactor

SteamTurbineGear

Fuel

Boiler

Oil,LNG

Conventional

propulsionsystem(here:steam)

Water

Condenser

Heat

Primarycircuit

Secondarycircuit

TurbineGear

Steam

Nuclear

propulsionsystem

Steam

Reactor

generator

Water

Condenser

©DNV2025

Heat

Maritimenuclearpropulsion

1

INTRODUCTION

6

Maritimenuclearpropulsion

Currently,nocommercialnuclearfacilitiesareinopera-

tiononcivilianshipsoroffshoreplatformsanywherein

theworld.Yet,fromaneconomicpointofview,several

compellingargumentssupporttheirpotential,notablylowandpredictableenergycosts,albeitwithhighinvestmentcosts.Asthisisatechnologythatproducesnoemissions,theclimateandenvironmentalbenefitsarealsoclear

(DNV,2023)(DNV,2024).Fromanoperationalperspective,nuclearpropulsionenhancesflexibilitybymakinghigherspeedseconomicallyfeasible,evenforlargervessels,

whilethereducedneedforbunkeringinfrastructurecouldhaveamajorimpactontheglobalfleet.

Thisraisesthepivotalquestion:howmighttheseoppor-tunitiesberealizedacrosstheworld?

Theaimofthispaperistodescribethestateofplayof

internationalcommercialactivitiesutilizingnuclearfissionforpropulsionorpowergenerationatsea,andtoprovideabasisfordevelopingastrategytocombinetwocom-

mercialindustrieswithlittlehistoricalcooperation.

Thepaperisdividedintofourparts.

First,inChapter2wedescribethehistoryofmaritime

nuclearpropulsion,providingabriefoverviewofexperi-enceswithnuclear-poweredcivilianmerchantshipsandotherrelevantactivities.Inthischapter,wealsointroducethemaritimefuelcycleandoutlinetheprinciplekey

elementsthatarerelevanttothis,includingthe‘frontend‘(activitiesbeforethereactor,suchasfuelproductionanddelivery)and‘backend‘(post-usemanagement,includingpotentialreprocessingandfinaldisposalofwasteprod-uctsthatcannotbereused).

Secondly,inChapter3,weexaminethereadinessof

civiliannuclearpropulsiontechnologies,comparingthemtoland-basedcounterparts,whileexaminingpreferred

propertiesandcandidatetechnologies,suchaspressur-izedwaterreactors(PWRs),smallmodularreactors(SMRs),moltensaltreactors,lead-cooledreactors,high-tempera-turegasreactors,andheat-pipereactors.

Therealizationofcommercialnuclearpropulsionisalso

dependentonnon-technologicalfactors,andinthethirdpartofthepaper,inChapter4,weprovideadetailed

overviewoftheregulatoryframeworksthatwillbe

requiredforafunctioningnuclearpropulsionindustrytobeinternationallyrecognized,andtoenjoyahighlevelofpublicacceptance.Thiswillinvolvemultiplenationalandinternationalactorsandwilldependonclosecooperationbetweenallparties.

Finally,thesuccessfulemergenceofacommercialmari-timenuclearpropulsionindustrywillhingeonviablebusi-nessmodelsandcosts,andthesefactorsareanalysed

inChapter5.Businessmodelsmustaddressdifferent

factorssuchasownership,leasing,crewsize,andsup-ply-chainmanagement,whilecostcompetitivenesswilldependontheabilityoftheindustrytoimplementstan-dardization,massproduction,andefficiencymanning.

Thesefactorsareallclarifiedthroughadetailedcase

study,presentedinChapter6,wherewesimulatethe

potentialcostlevelsmarinenuclearreactorswillneed

toachievefornuclearpropulsiontoberelevantforthemerchantfleet,andhowthismayaffecttheintroductionofthetechnologyininternationalshipping.

7

Maritimenuclearpropulsion

2

CIVILIANMARITIMENUCLEAR

PROPULSION:BACKAGAIN?

Highlights

–Earlymerchantnuclearshipsdemonstratedtechnicalfeasibilitybutlackedcommercialsuccess,andnocivilianmaritimenuclearfacilitieshavebeencommissionedformorethan40years.

–Themaritimenuclearfuelcycleencompassesallstagesfrom'frontend'to'backend'andincludesuraniummining,enrichment,fuelfabrication,reactoroperation,andspentfuelmanagement.

–Maritimeinfrastructuremustadapttothedemandsofthemaritimefuelscycle,withspecializedyardsandportsfornuclearoperations.

–Whilemuchexperiencecanbegleanedfromnuclear-propelledvesselsformilitarypurposes,theirrelevancetofuturecommercialmaritimenuclearinstallationsislimited

8

Maritimenuclearpropulsion

9

Shipping'sexperiencewithnuclear-poweredvesselsremainslimited.

Whilesomelargecountries,abovealltheUS,United

Kingdom,France,Russia,andChina,todayutilizenuclearenergyextensivelyinboththecivilianandmilitarysec-

tors,thedevelopmentofbothonshorepowergenerationandmaritimenuclearpropulsiondidnotproceedas

expectedatthebeginningofthenuclearage.ApartfromexploratorytestsinRussia,nocivilianmaritimenuclear

facilitieshavebeencommissionedformorethan40years.

However,nuclearisre-emergingasanoptionforfos-

sil-freeenergy.Thishasalsoextendedtothemaritime

industry,wherenuclearenergyhasgainedrenewedinter-est,bothasameansofpowergenerationonsea-basedplatformsandfornuclearpropulsionsystems(DNV,2023)(DNV,2024).

Therearenumerousexamplestodayofnewactors

demonstratinginterestinnuclearenergyinshipping.

TheUKtooktheinitiativein2022toaccedetothe

NuclearCode(seeChapter4),oneofthefewrelevant

internationallegalinstruments.(MandraandOvcina,

2022).Chinaisdescribedasapioneerintheapplicationofnucleartechnologytodecarbonizeshipping(Wang

andQuiwen,2025),andtheChineseshipbuildingcom-panyJiangnanShipbuildingGrouphasdemonstrateditseffortstomakeprogressinthedesignofnuclear-pow-eredmerchantships(MandraandOvcina,Offshore

Energy,2023).MajorshipbuildingcompaniesinSouthKoreahavetakenseveralinitiativesthatdemonstrate

theirintentionsandexpertiseinthefieldofmerchantnuclearshipping(WorldNuclearNews,2025;Nauti-

calVoice,2025).Additionally,asdescribedinthenextchapter,severalreactormanufacturersinothercoun-triesareexploringhowtheirtechnologycanbeutilizedinmerchantshipping.

Acentralcomponentofallfuturedevelopmentsinmar-itimenuclearpropulsionwillbethenuclearreactors,

anintegratedpartofacomprehensivetechnological

systemknownasthenuclearfuelcycle.Beforeconsider-ingthetechnical,commercial,andregulatoryaspectsofmaritimenuclearpropulsion,thisfuelcycleisdescribedbelow,togetherwiththemostrelevantexperiences

andtechnicaldatafromtheveryfirstnuclearmerchantvessels.

2.1Themaritimenuclearfuelcycle-inperspective

Historicalexperiencessuggestthat,intheearlystages

ofmaritimenucleardevelopment,conventionalPWR

technology–water-cooledlikemostland-basedreac-

tors–wasthepreferredchoicefornavalvesselsand

otherexploratoryprojects.Savannah,enteringservicein1962,demonstratingthe-thenUSPresidentEisenhower's'AtomsforPeace'initiative,wasthefirstevernuclear-pow-eredcargo-passengership.ThiswaslaterfollowedbytheGermanOttoHahnandtheJapaneseMutsu,allthreeves-selsusingPWR-typereactors(SchøyenandSteger-Jen-

sen,2017).

Followingtheinitialphaseofthe1950sand60s–anerathatusheredintheso-callednuclearage,includingthelaunchofthefirstnuclear-poweredships-theexpansionofnuclearenergylevelledoffinthe1980sand90s,bothintermsofnumberofplantsandenergygenerated,withonlyRussiacontinuingtocommissionnuclear-poweredvesselsforcivilianuse.

FIGURE2-1

Themaritimenuclearfuelcycle(uranium-based)

Thefrontend-part1:

Mining/conversion/

enrichment/fuel

fabrication

The

backend(b)-

part3:

Disposal

Thepower

generation-

part2:

Thereactor

Continueduse

inanotherfacility

The

backend(a)-

part3:

Storage

©DNV2025Source:WorldNuclearAssociation,2025

Maritimenuclearpropulsion

10

RegardingthenowdecommissionedexploratoryvesselsfromtheUS,Germany,andJapan,theland-basedfuel

cyclewasusedwithsomeadaptationsforuseatsea.

Althoughmaritimeapplicationshavedistinctrequire-mentsforfuelandsupportinginfrastructure,noneofthesecountriesestablishedatrulydedicatedmaritimefuelcycleatthatstage.

Theprincipalelementsofamaritimefuelcycleareout-

linedinFigure2-1,traditionallydividedintoa'frontend'(activitiesbeforethereactor,suchasfuelproduction)anda'backend'(post-usemanagement,includingpotentialreprocessingandfinaldisposalofwasteproductsthat

cannotbereused).

Industrially,theinitialstagesofthemaritimenuclearfuelcycle–suchasminingandmilling–areidenticaltothoseusedforland-basedreactors.However,fuelproduc-

tionprocesses,includingqualificationandfabrication,

typicallyneedtobetailoredtothespecificreactortypeanditsintendedmaritimeapplication.Inthelongerterm,themaritimenuclearfuelcyclewilldivergesignificantly

fromitsland-basedcounterpart,withshipyardsandportsemergingaskeyphysicalandlogisticaldifferentiators.

TheonlycountrywhichhaspursuedamaritimefuelcycleonanindustrialscaleisRussia.Tennuclear-powered

shipshavebeenconstructed–allpartoftheRussian

icebreakerfleet,operatingoutofapermanentbaseinMurmansk–inadditiontoonefloatingpowerplant,cur-rentlyinoperationinPevek,intheRussianfareast.Theicebreakerfleet,formallyownedbytheMurmanskShip-pingCompany,hasbeenusedprimarilybytheRussianGovernmentformanyyears.

2.1.1Thefrontend-thefueltechnology

Fuelisthemostfundamentalcomponentofanuclear

system,containingthefissilematerialwhichprovidestheenergyneeded.Thefissilematerialinthefuelcanbeauraniumisotope-uranium-235(U-235)oruranium-233

(U-233)–orplutonium-239(Pu-239),asdescribedinFig-ure2-2.U-235isfissile,andtheonlyfissileisotopefoundinnature,whileU-233canbemade(produced)inareac-torfromthorium-232(Th-232).Mindfulofthedifferencefromfissilematerials,Th-232isthereforecalled'fertile',asdescribedinFigure2-3.Thereareotherimportant

groupsofmaterial;U-238,likeTh-232,isfertilebecauseitcanbeconvertedintothefissileisotopePu-239by

absorbingneutrons.Uraniumore,whichismined,con-tainsonly0.7%U-235,whichiswhynuclearfuelisusuallyenrichedtoahigherproportionofU-235–3-5%U-235,i.e.anincreasedenrichmentlevel.

Forcivilianpurposes,fuelwithanenrichmentlevelbelow20%istheonlyoption,ashigherlevelsareconsideredanunacceptableproliferationrisk.Nuclearfuelforcommer-cialland-basedpowerplantsisoftenreferredtoaslow-en-richeduranium(LEU),whichindicatesanenrichmentlevelofabout3%to5%.Incontrast,somecountries,suchastheUS,onlyusefuelenrichedupto90%wherecompactness

FIGURE2-2

Themostrelevantfissileisotopesfornuclearfuel

FISSILENUCLEI

Neutron

Neutron

Neutron

©DNV2025

+

+

+

233U

235U

239Pu

Fission

reaction

Fission

reaction

Fission

reaction

isbeneficialorpotentiallydecisiveforthepurposeofthefacility,asfortheirmilitaryvessels.

Sincehigherenrichmentcanleadtomorecompactcores,aformofHALEU(High-AssayLow-EnrichedUranium)is

astartingpointformanyofthenewfueltypesforcandi-datecivilianmarinereactors.Whilehigherenrichment

canoffersignificantoperationaladvantages,italsoraisesconcernsaroundcostandsecurityofsupply.Fuelquali-ficationcanalsobeachallenge,especiallyiftheaimistousefuelenrichedtomorethanthe3%to5%U-235.

TheRussiancaseisalsoimportanttoillustratetheroleofenrichmentinnuclearfuel.RussiancargoshipSevmorput,commissionedin1988,reportedlyused90%enriched

fuel,althoughthecostofthisremainsunknown