Radiation detection and measurement for non-destructive characterization and control in nuclear media. Abdallah Lyoussi (CEA) IEEE DL Capetown, July 7-17, 2018 IEEE NPSS International School for Real Time Systems in Particle Physics 2018 A. LYOUSSI (CEA/DEN/CAD) FRANCE [email protected] SUMMARY INTRODUCTION Specific features, constraints and requirements Examples of radiation measurements and associated instrumentation for : - In Pile Measurements - Radioactive waste characterization and control Conclusions and prospects RADIATION DETECTION & MEASUREMENTS: APPLICATION DOMAINS / SUB-DOMAINS Domain « Materials Science & Industry » Domain NDT / Neutronography K / Industrial «Geophysics» measurement/Imagery Oil & Gas A Neutron and Photons Moisture monitoring B J facilities Applications of Reactor monitoring / C In‐core I Instrumentation Domain and radiation Reactor monitoring / Fundamental Physics D «F. Physics & Space » detection Ex‐core H systems Nuclear facility E systems Homeland security Domain Environment Control F «Security » & Dose Rate Monitors Domain «Nuclear» G Medical imaging Domain «Medical» Nuclear Media : Nuclear Fuel Cycle Concentration Mining Natural Conversion Uranium Enrichment © CEA Reprocessed Depleted Uranium Uranium Storage Vitrified Plutonium HLW Compacted ILW UOx Fuel Storage Ultimate Fabrication Rad Wastes MOX Fuel MA FP Fabrication L&ILW-VC Spent fuel Reprocessing Plant Reactor Storage Spent MOX fuel Nuclear Fuel Cycle : Instrumentation & measurement are key aspects for control & characterization Main in-pile measurements Neutron & Photon Flux T, Dimensions , Nuclear Heating Defects, Failure Conventional measurements Mechanical Loading Neutron Dosimetry Fission gas release, fuel Neutronic Parameters movement Temperature, Pressure IN‐PILE MEASUREMENTS Physical‐Chemical parameters Mass Flow Void fraction, diphasic flow Within severe constraints, a real R&D and Innovation challenge ! | PAGE 6 INSTRUMENTATION & MEASUREMENTS IN NUCLEAR MEDIA Modeling / Simulation is currently used during R&D as well as during routine issues of Instrumentation and measurement: From Design to Analysis (Sensor Design & Modeling, Detection Efficiency, Nuclear Data…). e.g. TRIPOLI, MCNP, GEANT4, FNDS, MATISSE… Dosimetry, Gamma and X-ray spectrometry, Gamma and X Imaging, Neutron Imaging, Alpha radiography, Beta spectrometry, passive & active neutron measurement, PNAA, DNAA, Photon interrogation. CHALLENGES FOR INSTRUMENTATION & MEASUREMENTS IN NUCLEAR ENVIRONMENTS Reliable impossible or difficult maintenance on irradiated objects Accurate despite a very severe environment to follow modelling progress; ex: µm dimensional measurements, ∆T<5°C Miniature narrow location to get maximal neutron flux: few mm available Corrosion resistant operation in pressurized water, high temperature gas, liquid metals… High temperature resistant > 300°C, up to 1600°C Neutron / “resistant” Sensitivity & Selectivity dose > 15kGy/s and > 10dpa/y SUMMARY INTRODUCTION Specific features, constraints and requirements Examples of radiation measurements and associated instrumentation for : - In Pile Measurements - Radioactive waste characterization and control Conclusions and prospects INSTRUMENTATION & MEASUREMENTS IN NUCLEAR MEDIA IN PILE INSTRUMENATION AND MEASUREMENT MEASUREMENT & INSTRUMENTATION FOR NDA Reminder : Main Aim of Nuclear Reactor Measurements : To reduce uncertainties To reduce uncertainties at each step of the process; from conceptual design to final running of nuclear system(s) Basic/Fundamental Data Online Monitoring Measurement of Basic Monitoring & Control in Physical Data NPP Verification Design Tools Smart/Analytical Experiments Global/Integral Experiments on Predictive / Calculations ZPR Reactors Model Development Check, verify, predictions Validation of Models/ Calculation schemes In Pile Measurements, Qualification and Testing in 11 MTRs IN-PILE INSTRUMENTATION & MEASUREMENT : CHALLENGES AND CONSTRAINTS Harsh environment High dynamic range T (1600°C), P (155 bar) >10 decades for n and Corrosion Time and spatial Gradients Radiations (dpa, transmutation) Miniaturization (few mm3) High energy range for n/ n : 9 decades – 10-8 - 20 MeV Deported acquisition system : 1 eV - 10 MeV up to 100 m In-core CEM Measurements Noise / low signal Mixed field n, Selectivity Maintenance Reliability Timing of the measurement On line(µs) - Off ligne (fading) Calibration in situ / Drifting Quantitative : Absolut/relative values ( < 1 to 10% - 2) Flux, Fluences, Doses, T°, P, Dimensions Characterization : Energy Spectra (n,) Mapping, Gradients, Evolutions,.. Prototype development duration : 5 to 10 years High cost for qualification (irradiation) IN-PILE MEASUREMENTS Objectives and Requirements In-pile measurements are essential to: • Monitor the experiments Objectives of irradiation tests : Assess / verify / increase the precision of behavior laws under irradiation Studied property Influence parameter (ex : fragility, cracking, corrosion, conductivity, etc.) (temperature, physicochemical conditions, etc.) Integrated flux / dose damages All these parameters must be accurately measured ! • Check safety parameters = check that some specified parameters stay in their acceptable range (e.g. : temperature, pressure, etc.) PAGE 13 What are the Objectives of a MTR (Material Testing Reactor) ? MTR allows to reproduce on a small scale, real power plant conditions and in some cases, more severe conditions for Material screening (comparison of materials tested under representative conditions) Material characterization (behaviour of one material in a wide range of operating conditions, up to off-normal and severe conditions) Fuel element qualification (test of one / several fuel rods (clad+fuel)) JHR: 3 MAIN OBJECTIVES R&D in support to nuclear Industry Safety and Plant life time management (ageing & new plants) Fuel behavior validation in incidental and accidental situation Assess innovations and related safety for future NPPs Radio-isotopes supply for medical application reference possible evolution MOLI production JHR will supply 25% of the European demand (today about 8 millions protocols/year) and up to 50% upon specific request JHR will be a key tool to support expertise Training of new generations (JHR simulator, secondee’s program) Maintaining a national expertise staff and credibility for public acceptance Assessing safety requirements evolution and international regulation harmonisation It is real: The Provençal Blue Sky…. | PAGE 16 JULES HOROWITZ (JHR) MTR REACTOR JULES HOROWITZ (JHR) MTR REACTOR Reflector Core Φ ≥ 5.5 1014 n/cm².s Φ ≥ 5.5 1014 n/cm².s > 1 MeV 20 fixed locations Φ ≥ 1015 n/cm².s > 0.1 MeV 6 mobile locations Thermal neutron flux Fast neutron flux Material ageing (up to 16 dpa/y) Applications : Material and fuel samples irradiation/ageing Radio-isotopes production for medical use … Geometry: From 34 to 37 cylinder-shaped fuel assemblies U3Si2-Al fuel enrichment of 19,75% then 27% Aluminum racks (hosting all the fuel assemblies) Hafnium control rods (in the center of fuel assemblies) Beryllium reflector 1. Contexte, enjeux et objectifs | PAGE 18 IN-PILE MEASUREMENTS Main Stakes Radiations Physical parameters Reduction of uncertainties in Better characterization of thermo- experimental conditions hydraulic conditions - Neutrons / gamma flux temperature field / fluid flows - Neutron spectrum - Neutron fluence Better knowledge of nuclear heating design of experimental devices Highly instrumented experiments Major stack for JHR Online measurement of « Cook and look » experimental parameters Material behavior Fuel improvement and qualification New materials, better representativeness - Fission gas release - Temperature - Pellet-cladding interaction - Deformations (creep…) - Accidental conditions (LOCA) Origin and Basics of Nuclear Heating Fuel Experimental channel (n,p)3 (n,)4 N-Transportn N 2 Prompt Activation (few mn to h) P-Transport P n’) (n, 1 ) / p N (n, N Delayed Collisions N N Bremsstrahlung e - - D-Transport R Photoelectric, Compton Or Pair Production effect - e - Prediction of reached temperatures Nuclear Nuclear heating of heatingDimensioning in fuel of Heat Source experimental channels experimentalelement irradiation devices and systems 1Radiative Capture 2Inelastic Scattering 3 4Non-Radiative Capture C. Devita et al. (2016) : « Étude et Optimisation de Calorimètres en Milieu Inactif Dédiés à la Mesure de l’Échauffement Nucléaire dans le Réacteur Jules Horowitz : Des Phénomènes Physiques à l’Étalonnage »; AMU Thesis defended in 2016. NUCLEAR HEATING IN JHR Photon heating is the main contributor to total heating in non-fissile materials and leads to temperature increases. Heated materials must therefore be accordingly cooled down so as to eliminate risks of local boiling ,e.g. around hafnium rods, and of creep deformations, e.g. of the aluminum rack. A good knowledge of the profiles of photon heating in irradiation devices is also necessary for the design of irradiation experiments. Temperature of irradiated samples is one of the key parameters to establish the representativeness of JHR irradiation with regards to irradiation in other light-water reactors, e.g. Pressurized-Water Reactors(PWR). Depending on expected values of heating, irradiation devices must appropriately be designed with systems to monitor and control sample temperature. It was estimated* that an uncertainty of 5% (at one standard deviation) on calculated photon heating, associated with the nuclear data used