Bertalot, Luciano

Fischer, Ulrich

Juarez, Rafael

Serikov, Arkady

KITopen

Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 1Fusion neutronics computations for ITER Diagnostic Generic Upper Port PlugArkady Serikov 1, Luciano Bertalot 2, Ulrich Fischer 1, Rafael Juarez 31 Karlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany2 ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex, France3 Departamento de Ingeniería Energética, ETSII-UNED, Calle Juan del Rosal 12, Madrid 28040, SpainEmail corresponding author: arkady.serikov@kit.eduDisclaimer: ITER is the Nuclear Facility INB no. 174. The views and opinions expressed herein donot necessarily reflect those of the ITER Organization.18th International Conference on Emerging Nuclear Energy Systems (ICENES 2017)- Synergy Innovation between Nuclear Energy and Renewable Energy -Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 2IntroductionObjectives – CAD-based neutronics computational support for design development of the ITERDiagnostic Generic Upper Port Plug (DGUPP) which will host many Diagnostic systems.The objectives have been reached by Monte Carlo (MCNP) radiation transport and activation analysesresulting in developing new 3D MCNP model and studying potential design improvements for radiationshielding of the Port Interspace (PI) where personnel access is planned for Upper Port maintenance.~45 Diagnostic systems to be installed for ITER machine protection, control and physics studies:PortInterspace(PI)PIPIPIPI PIUPPEPPLPFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 3He++(3.5Mev )D2,T2 FuelD++T+n ( 14MeV )He, D2,T2, impuritiesDivertor: particle and heat exhaustTritium fuel supplied from external sources.Plasma Shaping• D-shaped elongated plasma to increase plasma performance• Better confinement of plasma pressure by magnetic field, but needs vertical plasma stabilitySingle-null poloidal divertorconfiguration• Charged particles approaching the wall are then swept out of the plasma chamber into a divertor chamberDivertorX-PointScrape-Off LayerSeparatrixBlanket: neutron absorberPlasma Engineering FeaturesFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 4Monte Carlo (MC) radiation transport runs on supercomputers Simulation of independent random pathways on microscopic level, i. e.tracking of individual particle histories from "birth" to "death" Simulation can be computed on parallel multiprocessor systemsParticle #1 on CPU Slave #1……..Particle #N on CPU Slave #NMonte Carlo method is most suitable computational technique for nuclear fusion applications. It’s because of the following:• Geometry: complex fusion devices can be modelled in 3D geometry without major geometry approximations• Data: continuous energy representation as stored on evaluated data files in ENDF format• Calculation accuracy: only limited by statistics and data uncertainties (no numerical approximations)Used supercomputers:• Europe HPC-FF system at JSC (Germany);• CampusGrid OpusIB, SCC-KIT (Germany);• Europe HC3 at SCC-KIT (Germany);• Europe BWGrid (Germany)• IFERC-CSC Helios (Japan)• EUROfusion HPC Marconi-Fusion (Italy)The maximum speed-up was found on IFERC-CSC Helios supercomputer with OpenMP / MPI parallelization for non-biased MCNP5 run equalled 2500 on 4096 cores (or ~850 on 1024 cores, and ~450 on 512 cores) – because dependence of speed-up to number of cores is not linear due to ovethead time spent for communications betweeen computing nodes.Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 5Fusion Neutronics Methodology: Codes, Tools, Nuclear Data SpaceClaim software reads CAD models, solves geometry problems, allows to work in 3D without having to be a CAD expert CAD-to-MCNP conversion tools: MCAM  & SuperMC (FDS Team, China) McCad  (KIT, Germany)  Radiation transport calculations (n/gamma fluxes, nuclear heat, gas production): Monte Carlo code MCNP5 v1.60, MCNP6 (LANL) FENDL-2.1 (IAEA) neutron cross-section library B-lite MCNP model (IO) 40 tor-degree with all the components of ITER with modifications for the Upper Port area. C-lite model is not ready for Upper Port. Activation and Shut-Down Dose Rate (SDDR) calculations: FISPACT-2007 (CCFE) inventory code and EAF-2007 (EU) D1S code (ENEA) R2Smesh (KIT) Vizualisation: Paraview (Kitware) in vtk-formatTo reach the objectives, we used the state-of-the-art codes and interfaces approved for ITER neutronics applications:Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 6CAD-Based Monte Carlo Rad. TransportThree modelling approaches of CAD-based Monte Carlotransport simulations:1. Constructive Solid Geometry (CSG) – traditional approach with CADto Monte Carlo models conversion codes:– SuperMC (FDS team, China);– McCad (KIT fusion neutronics group, Germany).2. Unstructured Mesh (UM) geometry in MCNP6 (LANL, USA);3. Direct particle tracking technique with Direct Accelerated GeometryMonte Carlo (DAGMC) library – MCNP patch developed by Universityof Wisconsin–Madison, USA.Three stages of CAD (CSG) – to – MC models geometry conversion:1) Geometry simplification – remove the unnecessary details;2) Approximation of free-form and spline surfaces to 1st and 2nd order surfaces accepted of MCNP;3) Material definition with homogenization setting up the materialmixtures for the simplified cells, such as steel-water shielding composition of 60 vol.% steel – 40 vol.% water.Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 7ITER Diagnostic Generic Upper Port Plug (DGUPP) modelFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 8DGUPP with 3 constituent parts of the Diagnostic Shielding Module (DSM) used in following DGUP two MCNP models a) and b)a) Short-DSM DGUPP with only one DSM part (1);b) Long-DSM DGUPP with three DSM parts (1)+(2)+(3).Parametric study has been carried out on the shielding features oftwo DSM models:Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 9Neutron Flux maps of DGUPP in ITER C-lite MCNP modelShort DSM Long DSM up to CP – no streaming inside the port plug space Closure Plate (CP)Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 10Total neutron flux in DGUPPv2 with long DSM, threshold between (1e7-1e9) n/cm2/sNeutron flux map with Radial-Vertical cut Neutron flux map with Toroidal-Vertical cut Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 11Shut-Down Dose Rate (SDDR) maps of DGUPP in ITER C-lite MCNP modelShort DSM Long DSM Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 12SDDR (Sv/h) map in a quarter of the DGUPP with short DSMEnd of the short DSMBottom gapDemonstrated: Radiation streaming along the bottom and side gaps and inside the port structure behind the short DSM  need to improve DSM shielding designFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 13Isosurface 100 microSv/h at PFC#2Isosurface 1 mSv/hIsosurface 10 mSv/hShort‐DSM of DGUPP with SDDR isosurfacesAnalysis of Short-DSM: following the ALARA approach, to study a variant of DSM extended up to the Closure Plate under the 25 ton weight limit.Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 14Long‐DSM of DGUPP with SDDR isosurfaces100 microSv/h inside the long‐DSMIsosurface 1 mSv/hIsosurface 10 mSv/hIsosurface 100 microSv/h at PFC#2Isosurface 1 mSv/hFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 15Map isosurface in DGUPP with long DSM - to mitigate radiation streamingTrapezoidal‐to‐rectangular connection of the UP structureSDDR isosurface is formed by radiation streaming along the gaps at the UP lateral sides and neutron stopping at the trapezoidal‐to‐rectangular connection of the UP structure100 microSv/hFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 16Conclusions 1• Design development of the ITER Diagnostic Generic Upper PortPlug (DGUPP) is in progress.• 3D maps of neutron fluxes and Shut-Down Dose Rate (SDDR)with isosurfaces plotted the DGUPP allowed to find the radiationpathways, hot spots - most critical areas from neutronicsperspectives.• Revealed radiation streaming along the bottom and side gapsand inside the empty space of port structure behind the shortDiagnostic Shielding Module (DSM) motivated the need to furtherimprove the design of DSM.Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 17Conclusions 2 • A study has been carried out on a possible shielding improvementconsisting in elongation of the DSM in a variant of Long DSM. Theengineering implementation of the Long DSM option is still underconsideration. Along that, particular attention should be devoted toshielding insertion at the trapezoidal-to-rectangular connection ofthe UP rear structure. At this place neutron streaming could bestopped most effectively• Presented neutronics results were obtained in parametric study ofthe DGUPP shielding performance. These results are not absolute,they depend on other systems of ITER model C-lite v2 of 2015,which was updated afterwards.• Neutronic investigation is going on DGUPP improvement andSDDR reduction by taking into account the updated ITER C-Modeland by aiming to find engineering solutions.Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 18Progress on ITER construction: April 2017Bioshield will surround the cryostat, which in turn surrounds the steel vacuum vesselFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 19BACK slidesBACK slidesFusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 20SDDR in long‐DSM DGUPP with filled DGUPP‐VV gaps – streaming at lateral sides in blanket manifolds void space 100 microSv/hat PFC#21 mSv/h10 mSv/h100 microSv/h100 microSv/hStreaming at lateral sides in blanket manifolds void Fusion neutronics computations for ITER Diagnostic Generic Upper Port Plug,ICENES 2017   - INEST·  FDS, CAS   - Hefei, China, 24-27 April, 2017Page 2112345678960 degree100 degree140 degree180 degree‐60 degree‐100 degree‐140 degree‐20 degree+20 degree MCNP models  called “C‐lite” or “C‐Model” in 40 degree toroidal sector symmetrically represents the whole 360 degree of ITER machine; 40 degree is copying symmetrical 9 times by using the reflective boundary conditions.Port #1Port #1840 degree sectorof C‐Model9x40 degree identical toroidal sectorsC‐lite

Fusion neutronics computations for ITER diagnostic generic upper port plug

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Fusion neutronics computations for ITER diagnostic generic upper port plug

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