Gabrielli, F.

Sanchez-Espinoza, V. H.

English

KITopen

KIT – The Research University in the Helmholtz Association www.kit.eduInstitute for Neutron Physics and Reactor Technology Overview and Outlook of the Computational Activities atKIT for the Safety Assessment and the Radiological RiskPrediction of Nuclear Power PlantsF. Gabrielli, V. H. Sanchez-EspinozaF. Gabrielli | RPDMotivation 2Situation at May 2023https://www.euronuclear.org/glossary/nuclear-power-plants-in-europe/ Many and different NPPs under operation and goingto be deployed around Germany and worldwide Hypothetical severe accidents with FP releasecannot be excluded a priori (zero risk does not exist) Keeping the expertise on methodologies toassess the hypothetical risk that may arise fromthe operation of NPPs → one of the HGF’smission Evaluation of the radiological consequences ofhypothetical severe accidents in current operatingNPPs as well as in the innovative designs → one ofthe milestones of the NUSAFE Program of KITKIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDMotivation National regulators want to know reliable data about expected radiological risk Mandatory: Reliable evaluations of the radiological consequences of hypotheticalsevere accidents in a NPP → Emergency Planning Zones (EPZ) → support theemergency management during such events also in nuclear-free countries No national borders exist to the radiological impact of hypothetical severeaccidents in a NPP3 KIT-Zentrum Energie Seminars, 27.06.2023, On-lineDatesman, A.M. Radiobiological shot noise explains Three Mile Island biodosimetry indicating nearly 1,000 mSv exposures. Sci Rep 10, 10933 (2020). https://doi.org/10.1038/s41598-020-67826-5Nuclear Regulation Authority (2011) Results of airborne monitoring by the Ministry of Education, Culture, Sports, Science and Technology and the U.S. Department of Energy (in Japanese)F. Gabrielli | RPDNPP Technology Developments: Drivers 4AP-1000RR with MTR-FuelVVER-1200/V-491EPR GE ABWR APR1400SMR SMARTSMR NUWARKIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDReactor Physics and Dynamics (RPD) Group 5 Development, validation, and improvements of the calculation tools dealingwith different physical domains of the nuclear reactor safety Combination of in-house and external codes embedded in internationalcooperations (USNRC CAMP, USNRC CSARP, KIT/IRSN strategic cooperation) Research areas Multiphysics and multiscale approach to core and plant analyses(nominal operation and Design Basis Accidents) Validation of codes using KIT and external experiments Uncertainty and Sensitivity Analyses Analysis of severe accidents in NPPs Radiological consequences of severe accidentsKIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDMulti-physics (core) and -scale (plant) analyses 6 Use of the thermal hydraulic solvers in regions of a nuclear power plantwhere their physical models and spatial resolution assure the best results Increasing the prediction accuracy, fidelity and spatial discretization ofcomputational domainsPin-by-pin core analysisKIT-Zentrum Energie Seminars, 27.06.2023, On-line plus…coupling Neutronics/TH/CFD codes – MultiscaleanalysesF. Gabrielli | RPDKIT Multiphysics Analyses Current FrameworkKIT-Zentrum Energie Seminars, 27.06.2023, On-line H2020 Project McSAFER (High-Performance Advanced Methods and ExperimentalInvestigations for the Safety Evaluation of Generic Small Modular Reactors)(KIT/INR/RPD as coordinator) (www.mcsafer-h2020.eu) Advance safety research for Small Modular Reactors (SMR) by combining experimentalinvestigations and innovative numerical simulations. CAMIVVER (Codes and Methods Improvements for VVER Comprehensive SafetyAssessment) (www.camivver-h2020.eu) (KIT/INR/RPD as WP Leader) Development and improvement codes (NT, TH, safety) and methods for VVERcomprehensive safety assessment (Nominal and accidental conditions, validation)7F. Gabrielli | RPDHypothetical Severe Accidents in LWRs: OverviewKIT-Zentrum Energie Seminars, 27.06.2023, On-line Hypothetical severe Accidents in NPPs are generally triggered by a failure withinthe reactor cooling system and by multiple dysfunctions, including the failure ofsafety procedures → Namely, no proper removal of residual power from thecore occurs.8 ..may lead to large core degradation, failure ofthe safety barriers, and a massive release offission products from the vessel to thecontainment and the environment. Challenges: Several non-linear phenomena occurring simultaneously Accident progression and source term dependent on the kind ofreactor, i.e. PWR, BWR, VVER,SMR, … and on the scenariosF. Gabrielli | RPDKIT Strategy for SA Analyses (basic route) KIT-Zentrum Energie Seminars, 27.06.2023, On-line Source Term (ST): The types, quantities, and physical and chemical forms of theradionuclides present in a nuclear facility that have the potential to give rise toexposure to ionizing radiation, radioactive waste or discharges. Step-wise calculation route: Status of the core when the SA occurs, i.e. burn-up (multiphysicsanalyses) Analysis of the accident scenario (integral codes) FPs behavior during the in-vessel and ex-vessel phases Source Term Dispersion in the environment (decision support system tools)9F. Gabrielli | RPDKIT Strategy for SA Analyses (extended route) KIT-Zentrum Energie Seminars, 27.06.2023, On-line Source Term (ST): The types, quantities, and physical and chemical forms of the radionuclidespresent in a nuclear facility that have the potential to give rise to exposure to ionizing radiation,radioactive waste or discharges. Step-wise calculation route: Status of the core when the SA occurs, i.e. burn-up (multiphysics analyses) Analysis of accident scenarios for different initiators (integral codes) FPs behavior during the in-vessel and ex-vessel phases Source Term Uncertainty propagation and assessment of ST database (integral codes + UQtools) Uncertainty Quantification of the ST database (integral codes + UQ tools) ST prediction (integral codes + UQ tools + predictive algorithms) Dispersion in the environment (decision support system tools)10F. Gabrielli | RPDKIT Strategy for SA Analyses - Codes 11 KIT-Zentrum Energie Seminars, 27.06.2023, On-line Combination and improvement of in-house and foreign codes Evaluation of the fuel inventories (CASMO,SCALE/ORIGEN,KORIGEN) Severe Accident analyses and source term evaluation ASTEC (KIT/IRSN agreement, KIT as co-developer) MELCOR (USNRC/KIT Cooperative Programs CSARP and MCAP) Uncertainty and sensitivity analysis → training database of ST from integralcodes KArlsruhe Tool for Uncertanty and Sensitivity Analyses (KATUSA, in-house) Fast Source Term Code (FSTC, in-house) → ST prediction → BayesianNetwork Algorithms Radiological consequences of FP release in the environment Java Real-time On-line Decision Support System (JRODOS, KIT/ITES)F. Gabrielli | RPDThe ASTEC CodeKIT-Zentrum Energie Seminars, 27.06.2023, On-line ASTEC (Accident Source Term Evaluation Code) developed by IRSNsince 1996 to analyze the complete SA scenario from the initiatingevent until radioactive release out of the containment in Gen. II andGen III water-cooled reactors. KIT supporting the code development since2020 (KIT-IRSN License Agreement). Code validation against KIT and foreignexperiments KIT as unique and excellent multi-scienceenvironment12F. Gabrielli | RPDLarge scale test facilities at KITKIT-Zentrum Energie Seminars, 27.06.2023, On-line13QUENCHCore coolability and debris coolingMCCI LIVEHYKAMOCKAContainment phenomenaF. Gabrielli | RPD14KIT calculation Platform (basic route) Complete calculation chain from fuel inventoryevaluation to the analysis of FPs dispersion in theenvironmentKIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDThe ASTEC/JRODOS PlatformKIT-Zentrum Energie Seminars, 27.06.2023, On-line Isotope-wise mass data Isotope-wise activity data ASTEC/JRODOS coupling assessedat INR → first-of-its-kind15W. Raskob, 2012. Radiological consequences to the environment resulting from Severe Accidents,Course on Severe Accident Phenomenology and Management, KIT, July 10th -11th.F. Gabrielli | RPDKIT SA Analyses Current Framework (1/2)KIT-Zentrum Energie Seminars, 27.06.2023, On-line EU Management and Uncertainties of Severe Accidents (MUSA) Project (2019-2023) (KIT/INR/RPD WP Leader, KIT/Framatome GmbH joint contribution) Assessing the capability of SA codes when modelling SA scenarios for Gen. II/III/III+reactor designs and SFPs by using the UQ methods. EU Safety Analysis of SMR with PAssive Mitigation strategies - SevereAccident (SASPAM-SA) Project (2022-2026) (KIT/INR/RPD WP Leader) Hypothetical severe accident analyses of Integral Pressurized Water Reactor (iPWR),Emergency Planning Zone (EPZ), European licensing analyses needs EU SEvere Accident Research and Knowledge ManagemenT (SEAKNOT)Project (2022-2026) (KIT/INR/RPD WP Leader) Shaping up a roadmap for severe accident research to reduce the remaininguncertainties and measurable progress in the practical elimination of radiologicalconsequences.16F. Gabrielli | RPDKIT SA Analyses Current Framework (2/2)KIT-Zentrum Energie Seminars, 27.06.2023, On-line EU Artificial intelligence for the Simulation of Severe AccidentS (ASSAS)Project (2022-2026) (KIT/INR/RPD WP Leader) First-of-its-kind extensive use of AI algorithms for developing fast-runningsurrogate models for severe accident modelling IAEA CRP I31033 on U&S Methods for SA Analysis in Water Cooled Reactors(2019-2024) (KIT/INR/RPD CRP Chair) OECD/NEA QUENCH-ATF Project (2021-2024) (KIT as Coordinator) IAEA CRP T12032 ‘Testing and Simulation for Advanced Technology andAccident Tolerant Fuels’ (ATF-TS) (2019-2024)17F. Gabrielli | RPDActivity in the Vessel and in the ContainmentKIT-Zentrum Energie Seminars, 27.06.2023, On-line Significant amount of the activity in the vesseltransported to the containment. Effect of the a different inventory and scenariolooks the dominant.18Initial InventoryVolatility Element BOC (Ci) EOC (Ci)Noble GasesXe 4.06E+08 4.53E+08Kr 1.17E+08 1.24E+08Very VolatileI 1.16E+09 1.28E+09Cs 1.00E+09 2.08E+10Moderately VolatileTe 6.10E+08 6.88E+08Sr 2.98E+08 3.76E+08Ba 1.48E+10 1.87E+10LessVolatileRu 3.50E+08 4.16E+08La 6.04E+08 6.66E+08Ce 4.49E+08 5.12E+08MBLOCA SBLOCAF. Gabrielli | RPD19Example of Application (PWR KONVOI NPP) ASTEC model of a generic KONVOI NPP Scenario MBLOCA (12’’ on the cold leg)Cattenon site (France)Radiological consequences:Cs134 contamination (winter time)MBLOCA SBLOCAXe release to the environementKIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDVVER-1000 abd BWR Mark-I applications20 VVER-1000 (SBO+LBLOCA) BWR Mark-I (Peach Bottom) (SBO)Dose Rate(mSv/h)Kozloduy NPPActivity concentration ofCs species on cow’s milkKIT-Zentrum Energie Seminars, 27.06.2023, On-lineK. Mercan, F. Gabrielli, V. H. Sanchez-Espinoza and W. Raskob, 2022, "Analysis of the consequences of a LBLOCA with SBO severe accident in a generic VVER-1000 by means of ASTEC and JRODOS codes," Nuclear Engineering and Design, vol. 400, p. 112078, 2022.Murat, O., Sanchez-Espinoza, V., Gabrielli, F., Stieglitz, R., and Queral, C., “Analysis of the Short Term-Station Blackout Accident at the Peach Bottom Unit-2 Reactor with ASTEC Including the Esti ation of the Radiological Impact with JRODOS”, Submitted to Nuclear Engineer ing and Design (under review)F. Gabrielli | RPDThe In-house KATUSA and FSTC codesKIT-Zentrum Energie Seminars, 27.06.2023, On-line Source term evaluation affected by theuncertainties still existing on SAs modeling, i.e.MCCI. Framework: EU MUSA and German WAME projects. KATUSA and FSTC tools developed at KIT Python based Easy to be installed on any machine andenvironment Two ‘modes’: UQ and UQ+Prediction (FSTC) Verified against URANIE21A. Stakhanova, et al., Uncertainty and sensitivity analysis of the QUENCH-08 experiment using the FSTC tool, Annals of Nuclear Energy, Annals of Nuclear Energy, 169, p.108968.A. Stakhanova, et al., PRELIMINARY UNCERTAINTY AND SENSITIVITY ANALYSIS OF THE ASTEC SIMULATIONS RESULTS OF A MBLOCA SCENARIO AT A GENERIC KONVOI PLANT USING FSTC TOOL, Proc. of ERMSAR2022, 16-19 May 2022, Karlsruhe, Germany, DOI: 10.5445/IR/1000151444, https://publikationen.bibliothek.kit.edu/1000151444.F. Gabrielli | RPD22UQ of the ST during SAs12…NASTEC Source Term DatabaseASTEC/KATUSAASTEC+UQASTEC+FSTC Assessing a database of source term results for: Different scenarios Different NPPs, i.e. KONVOI, VVER-1000, BWR Mark-I, SMR (on-going)KIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDSource Term Database (UQ and Sensitivity)KIT-Zentrum Energie Seminars, 27.06.2023, On-line MBLOCA scenario in a generic KONVOI plant. 16 uncertain parameters, 300 ASTEC samples (2 failures), LHS employed23Xe release to theenvironmentFractionoftheinitial loadingXe release to the environment vs. Containment leakageA. Stakhanova, et al., PRELIMINARY UNCERTAINTY AND SENSITIVITY ANALYSIS OF THE ASTEC SIMULATIONS RESULTS OF A MBLOCA SCENARIO AT A GENERIC KONVOI PLANT USING FSTC TOOL, Proc. of ERMSAR2022, 16-19 May 2022, Karlsruhe, Germany, DOI: 10.5445/IR/1000151444, https://publikationen.bibliothek.kit.edu/1000151444.F. Gabrielli | RPDSource Term Prediction: Xe release to the EnvironmentKIT-Zentrum Energie Seminars, 27.06.2023, On-line Monte Carlo-based Bayesian inference model(MOCABA, Framatome) implemented in the FSTC tool ASTEC+FSTC (KIT/Framatome collaborationwork, BMWi WAME Project) Xe release predicted based on the total dose rate in theannulus Results of 300 samples were used for ‘prior’ 100 samples employed as ‘experiment’ For both sets uncertainty of input parameters arethe same Good prediction results → Very promising approach24E. Pauli, A. Stakhanova, et al., Prediction of the Radiological Co sequences of a Severe Accident Scenario in a Generic KONVOI Nuclear Power Plant, ERMSAR2022.First-of-its-kindF. Gabrielli | RPD25KIT calculation Platform (Extended route)ASTEC/KATUSASource Term DatabaseKATUSAUncertainty band of the FP release to the environment Providing JRODOS of the uncertainty band of the FPs releaseduring a SA ASTEC/KATUSA/JRODOS data and platform already available GOAL: improvement in the definition of the EmergencyPlanning ZonesST ± SigmaKIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDEffect of the ST Uncertainty on Radiological Consequences – Academic study (VVER-1000)KIT-Zentrum Energie Seminars, 27.06.2023, On-line26 Scenario SBO+MBLOCA on the cold leg scenario Site: Zaporizhzhia NPP Maximum acute effective dose: Best-estimate = 16.7 mSv, Worst-case = 48.7 mSvAcute effective doseWorst caseAcute effective doseBest-estimate caseF. Gabrielli | RPDHousing New ApproachesKIT-Zentrum Energie Seminars, 27.06.2023, On-line27 How to improve the current ASTEC/KATUSA/JRODOS platform? How to further improve the quality of the ST results to the emergency teams? How to house new technologies (for the SA research domain)?F. Gabrielli | RPDAI/ML in SA Analyes: ‚Housing‘ new technologies Artificial intelligence for the Simulation of Severe AccidentS (ASSAS) (2022-2026) (KIT as WP leader) Developing a proof-of-concept severe accident simulator based on ASTEC(Accident Source Term Evaluation Code). Generation of training database for developing surrogate models to beimplemented into ASTEC Joint INR/SCC contribution: KIT as unique and excellent multi-scienceenvironment28 KIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDNew Projects (AI/ML in SA Analyes) Several potentialities to be explored Make the code much faster w/o loosingin accuracya. Forward approach of the ASTEC+AI/ML Much larger database in the same wall-clock time → improvement ST predictionb. Backward approach of the ASTEC+AI/ML Forecasting when and which physicalmodels might fail Improvement of the code29 KIT-Zentrum Energie Seminars, 27.06.2023, On-lineF. Gabrielli | RPDEducation, Training, and DisseminationKIT-Zentrum Energie Seminars, 27.06.2023, On-line Internships/student research projects, Master theses, Doctoral theses Lectures on reactor physics, reactor dynamics and safety analysismethods at the Mechanical Engineering Faculty of KIT Framatome Nuclear Professional School (see https://www.fps.kit.edu/) KIT/CEA Frederic Joliot/ Otto Hahn Summer School on NuclearReactors "Physics, Fuel, and Systems” (https://www.fjohss.eu/) 2023 FJ/OH: ‘Digital Twins: New Horizons in Nuclear Reactor Design andOptimisation’, 23.08.2023-01.09.2023, GenoHotel, Karlsruhe Organization of ‘The 10th European Review Meeting on Severe AccidentResearch’ (ERMSAR2022), co-organized with IAEA and OECD/NEA (firsttime in ERMSAR) 118 participants (50 organizations, 21 countries), 60 technical papers30 https://www.nusafe.kit.edu/english/26.phpF. Gabrielli | RPDConclusionsKIT-Zentrum Energie Seminars, 27.06.2023, On-line31 Computational strategies are available and continuously under development at INR/RPD for the safety assessment of different reactor designs the prediction of the radiological consequences from severe accidents The application cover any nuclear reactor plant Importance of the NUSAFE Program to preserve knowledge and capabilities Activities embedded in international co-operations with the US NRC and French IRSN Active education, training, and dissemination work Outlook (going on): Small Modular Reactors (EU SASPAM-SA) New rector components (ATFs) (OECD/NEA QUENCH-ATF, IAEA CRP ATF-TS) Innovative calculation ‘routes’ employing AI/ML algorithms (EU ASSAS)

Overview and Outlook of the Computational Activities at KIT for the Safety Assessment and the Radiological Risk Prediction of Nuclear Power Plants

https://publikationen.bibliothek.kit.edu/1000161084/151086432

Overview and Outlook of the Computational Activities at KIT for the Safety Assessment and the Radiological Risk Prediction of Nuclear Power Plants

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