Bachmann, C.

Fischer, U.

Leichtle, D.

English

KITopen

KIT – The Research University in the Helmholtz Association www.kit.eduStrategical Approach for the Neutronicsin the European Fusion ProgrammeD. Leichtlea, U. Fischera, C. Bachmannba Karlsruhe Institute of Technology (KIT), Karlsruhe, GermanybEUROfusion – Programme Management Unit, Garching, GermanyD. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 2020IntroductionNuclear Design IntegrationNeutronics strategical approach for DEMOSystem-engineering integrationRecent applicationsFuture PlansConclusions2Content18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 2020European Fusion RoadmapDEMOIFMIF/DONESExperience in nuclear fusion technology R&DStrengthening nuclear design integrationImproving nuclear safety cultureIdentification of transversal, plant-level functionsNeutronics plays a fundamental role for the design, operation and safety of these facilities including the evaluation and verification of their nuclear performances.3IntroductionPre-concept DesignConcept DesignEngineering Design & Site Selection Construction CommissioningDEMO ScheduleDecision to Construct203820602039203720352033202920252014EDRCDR2020 2027 2051 206018 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 2020„Nuclear Design Integration“: attention to thedesign phase adopting appropriate technical andadministrative measures.EU DEMO Conceptual Design PhaseDEMO Design Authority supported by DEMO Central TeamNuclear Design Integration with dedicatedresponsibility.Identification, analysis and resolution of all radiation induced issues along the full life cycle of the nuclear installation.4Nuclear Design Integration18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 2020Progressing Nuclear Design Integration by integration of neutronicsworkflows in system-engineering design processes.Design iterations with full accountance of nuclear design and radiologicalprotection objectives.Based onAiming atValidated nuclear performance parametersRequirement verification and design validation5Neutronics Strategical ApproachEstablished proceduresQualified computationalmethodologyConfiguration & requirementmanagement18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 2020ToolsRadiation transport: MCNP, TRIPOLISERPENT, GEANT4, OpenMC …Activation: FISPACT-II, ACABShutdown coupled codes: MCR2S, R2S-UNED, R2Smesh, AdD1ScR2S (to be released)DataNeutron transport: JEFF, FENDLActivation: TENDLResponse files: for damage andgas production6Methodological Approach for DEMO*Neutronics workflows stipulated by Neutronics Guidelines. Recommendation on use of tools, data and requested nuclear responses.18 Nov 2020* IFMIF/DONES neutronics is basedon similar approach with specificpecularities:Neutron source from d-LiDeuteron/proton nuclear data…D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 2020Current focus on prime ingredientsRequirement ManagementCommon understanding of requirements (specifications)Complete and good requirementsProduct and process requirementsTransversal functions and requirementsConfiguration ManagementConfiguration definition and change controlUp-to-date, referenced and applicable dataConsistency of engineering/configuration and neutronics modelsData management7System-Engineering IntegrationSMART18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 20208Requirement ManagementRequirements derived from project objectives (goals) to describe a condition orcapability to be met or possessed by an item in the scope of the project. External constraints/regulations need to be accounted for.Collection, priorisation and elaboration.Hierarchical order, allocation, propagation.„Good“ requirements, e.g.:Traceable to the originConsistentVerifiableProjekt ObjectivesTL Req 1Req1.1Req1.2TL Req 2Req2.1Req2.2Req2.3StakeholderCustomerRegulatorPublic18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 20209„Neutronics Requirements“Task orientedTo provide nuclear responses of interestDesign of breeding blanket for DEMO: HCPB and WCLL design concepts18 Nov 2020Impact of radiation sources/fields•System design•Plant operation•Plant maintenance•Licensing•Safety case•DecommissioningProvision of nuclear parameters•Tritium production•Heating/power generation•Shielding performance•Activation, decay heat, shutdown dose•Radiation damage, transmutation, gas productionD. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202010„Neutronics Requirements“Task orientedTo provide nuclear responses of interestTo provide protection (shielding) requirementsTo verify compliance with load specifications and protection requirements18 Nov 2020Nuclear loads“Design against loads”Radiation sourcesPrimary loads: e.g. heating, damageSecondary loads: e.g. decay heat, shutdown doseLimits on loadsNuclear shielding“Design for shielding”Radiation transportPlasma neutron responsesActivation and decay responsesLimits on exposureShielding requirementsD. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202011„Neutronics Requirements“Load specifications related:To define nuclear loads on systems, structures and componentsProtection requirements related:To limit radiation loads relative to design or damage limits of sensitive and criticalsystemsTo constrain and limit exposure to ionizing radiation (ALARA)Quality requirements related:To follow Established Procedures18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202012Nuclear shielding requirementsInvestment protectionAgeing and damage limitsRadiological protectionExposure rate constraints/targetsComponent/location RequirementLimit (target)Port interspaceShutdown dose rate 12 days after shutdown~500 Sv/h (target)Port cells (occasional access)100 Sv/h (target)Maintenance hall above tokamak Tbd.In-cryostat area, [7] 100 Sv/h (target)Tokamak building areas beyond port cells requiring frequent access, [7]Shutdown dose rate 1 day after shutdown10 Sv/h (target)Critical electronic equipment Neutron fluence during operation0.01 n/(cm²s)Non-critical electronic equipment 100 n/(cm²s)Component/location RequirementLimit (target)Starter blanket FWDisplacement damage to Eurofer20 dpa2nd blanket FW 50 dpaDivertor cassette body (@ 180°C), [8] 6 dpaDivertor PFCs, [9] Displacement damage to CuCrZr10 dpa, possibly up to 20 dpaVVDisplacement damage 2.75 dpaNuclear heating, [10] 0.5-1 W/cm³(target)Activation, [2] Minimize (target)Cutting/re-welding location in IVC cooling pipesHelium production 1 appmSuperconductors, [11], [12] Total neutron fluence to epoxy insulator 1022/m²Fast neutron fluence to the Nb3Sn 1022/m²Neutron fluence to Cu stabilizer between TFC warm ups1-2·1021/m²Nuclear heating inwinding pack 50 W/m³From baseline documentationPlant Safety Requirement DocumentPlant Load Specification Nuclear Analysis HandbookPlant Description Document18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202013„Established Procedures“„Set of processes, instructions and guidelines which is qualified for the requested purpose usually on the basis of state-of-the art technology, proven methods and tools and good practices.”Due to lack of fusion neutronics Codes&Standards there is need to define references and quasi-standards.Including generic requirements on roles&responsibilities and suitable qualification/experience of involved actors.Including specific technical requirements on the activities and artefacts of the processes.Accounts for impact on performance, safety, cost and schedule by graded approach (level of rigorousness).18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202014Configuration managementIdentification of data to be put under configuration control and to be assigned to(technical) baseline documentation.Input, intermediate, output dataEstablished proceduresDatabases and configuration control documents are progressively issued:Geometry models for radiation transport (MCNP input)Material specificationsRadiation source termsIn future: Protection Important Components and Activities (safety classification)Nuclear Analysis Handbook ( Plant Load Specification) Living document to follow configuration/design changes and to provide reference data.Applicability assessment18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202015Data managementUp-to-date, referenced and applicable data itemsChange control, traceability, and applicability rangeSeries of subsequent analysis activitiesUpstream analysis result (or model) used in downstream calculation (or modelling)ModellingTokamak systemNuclear AnalysisNuclear heatPostprocessingMeshingThermal AnalysisCAD MCNP Tally Mesh18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 2020Problem-specific dataMaterial definitions, geometry models, assembly, operational conditions, environmental conditions, etc.Reference project dataSame as above, but for general applicationsGeneric project-independent dataNuclear cross sections, response functions, etc.Deficient/missing dataUse of assumptionsVerification & ValidationDatabases, repositoriesChange and version controlContinuous improvementSensitivity studies16Data classification18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202017Recent applicationsBreeder Blanket neutronics design supportDEMO tokamak global shielding improvementsDEMO sky-shine calculations18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202018Breeder Blanket neutronics design support18 Nov 2020Component HCPB [MW] WCLL [MW]Total BB 1941 1739Divertor 169 133.4VV 45 8Total reactor 2155 1880.4Global energy multiplication1.35 1.18TBR HCPB WCLLInboard 30 % 30.3 %Outboard 70 % 69.7 %Total 1.18 1.15WaterCooledLithiumLeadNew cooling layout IBPbLi (90% 6Li)Water (15.5 MPa)HeliumCooledPebbleBedRadial fuel breeder pinsLi4SiO4 (35 mol% Li2TiO3)Be12TiHe (8 MPa) Continous effort on optimizingnuclear performance (incl. shielding) under design constraintsD. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202019DEMO tokamak global shielding improvementsStrategical approachStatus of protection requirements and prioritiesAssessment of radiation mapping from plasma neutronsourceIdentification of key configuration and design optionsStudy of advanced „baseline“ configuration: VV andintercoil shieldsStudy of various options at port level18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202020DEMO tokamak global shielding improvementsStatus of protection requirements and prioritiesProtection objectivesRadiation sensitive equipment: „to the limit“Worker protection: „ALARA“(concurrent or competitive objectives!)Radiation source inventoriesIdentification, quantification (source strength)Localization (movable/transported sources)Radiation transport and shielding analysis18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202021DEMO tokamak global shielding improvementsAssessment of radiation mapping from plasma neutron sourceExcessive radiation loadsHot spots of nuclear heating density in TFCLeakage through ports and penetrations (pipework)Attenuation through in-vessel and vessel barrierShielding from the sourceStreaming and leakage mitigation18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202022DEMO tokamak global shielding improvementsIdentification of key configuration and design optionsPrimary shield barrier: Vacuum VesselThickening of In-Wall Shield at outboard sideFilling in of top/bottom inter-coil shield blockBulk shield extensions: Equatorial portplugsRadial extent of shield blocksStreaming mitigation: Upper portpenetrationsLeakage mitigation: Port duct walls18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202023DEMO tokamak global shielding improvementsStudy of advanced „baseline“ configuration: VV and intercoil shieldsGeneric layout of system architectureDesign approach towards global performanceNeutron transport with blocked port openingsPerformance of bulk shield barrierOverall reduction of in-cryostat neutron flux by 1-2 ordersPromising reduction at top/bottom of tokamakShutdown dose rate global maps (in progress)18 Nov 2020Thick VVD. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202024DEMO tokamak global shielding improvementsStudy of various options at port levelStreaming and leakage mitigationsStandardized local shield optionsReduction of radiation cross talk effectsPromising improvements on SDDR in port interspaces and in-cryostat volumesPort wallsLimiter shield18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202025DEMO sky-shine calculations18 Nov 2020Computational method and toolsADVANTG 3.0.3. for variance reduction (Denovo)MCNP5 v1.6 and MCNP 6.2MCNP source subroutine for reading Common decay gamma source filesAmbient dose equiv. H*(10) with flux-to-dose conversion coeff. (NCRP-38, ICRP-74)Scenarios1: On-load operation (plasma source)2: 1 second after shutdown3: In-vessel maintenance where the upper port is opened4: In-vessel maintenance where the upper port is opened and the BB is moved into the upper maintenance hallD. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202026DEMO sky-shine calculationsDose rate limit at site boundary 200	μSv/year18 Nov 2020Annual dose rate at site boundary withlarge margin below limit(plasma neutron source and associated tokamak activation)D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202027Future plansEnhancing neutronics frameworkProcesses for nuclear design integrationQuality assurance systemFocused R&D on coupled tools and interfacesQualification of workflows, including alternative MC transport codesR&D on nuclear data development and experimental validationExploitation of collaborative effortsNuclear Data: JEFF, FENDL, …Radiological protection: ITER OrganizationNeutronics worksflows in nuclear design integration: US-DOE (U Wisconsin; ORNL)18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202028ConclusionsStrategical approach for neutronics aims at integration of neutronics workflowsinto system-engineering context of Nuclear Design Integration.The workflows (established procedures) build on qualified methodology andsuitably adopted configuration/requirement principles.Comprehension of radiological protection objectives and their projectimplementation is a key prerequisite.Neutronics plays a fundamental role in defining global shielding strategies andverification of solutions.Future work includes streamlined R&D on qualified and efficient tools, data andworkflows in collaboration with the international fusion neutronics community.18 Nov 2020D. Leichtle et al., Strategical approach for the neutronics in the European fusion programme TOFE 202029Thank you for your attention!AcknowledgementSuggestions and ideas by G. Federici, P. Wilson, R. Grove,  C. Baylard, S. Ciattaglia, Y. QiuPictures/Data: Courtesy of EUROfusion (C. Gliss, C. Vorpahl, T. Franke, T. Eade, T. Berry, A. Čufar, D. Flammini, B. Kos, P. Pereslavtsev, F. Moro, et. al.)18 Nov 2020

Strategical approach for the neutronics in the European fusion programme

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Strategical approach for the neutronics in the European fusion programme

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