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A CHALLENGE FOR SUSTAINABLE, CLEAN ENERGY C.Borcea
NEUTRON DATA A CHALLENGE FOR SUSTAINABLE, CLEAN ENERGY C.Borcea Info Day Bucharest
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OUTLOOK INTRODUCTION NEUTRON DATA (ND): WHY AND HOW ND AT IRMM NP
CONCLUSION Info Day Bucharest
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INTRODUCTION RECENT HOT LINES IN THE NEWS: -CHERNOBYL -PRICE OF CRUDE
IMPLICATIONS: MAKE NUCLEAR ENERGY SAFE AND CLEAN BY -NEW GENERATION OF REACTORS -WASTE PROCESSING Info Day Bucharest
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NEUTRON DATA: WHAT IS THAT?
DATA CONCERNING THE CROSS SECTIONS OF NEUTRON INDUCED REACTIONS ON VARIOUS MATERIALS The neutron can: -scatter elastically -scatter in-elastically (followed by emission) -be captured (followed by gamma end/or particle emission) -induce fission -induce a (n,xn) or a (n,cp) reaction Info Day Bucharest
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Neutron data theory safety standards sustainability systematics
level densities spins, parities Temperature effects shielding waste Neutron data safety standards Safety margins Higher burn-up sustainability ADS , HTR Info Day Bucharest
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NEUTRON DATA: WHAT FOR? REACTORS OF A NEW GENERATION AND/OR ADS
RADIOACTIVE WASTE PROCESSING FUSION REACTORS (ITER) SAFETY AND SAFEGUARDS MEDICINE, FORENSICS ELEMENT TRACING, etc. Info Day Bucharest
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NUCLEAR ENERGY KEY ISSUES
SAFETY (keff) SUSTAINABLE (BU, CLOSED CYCLE) WASTE (P&T) NONPROLIFERATION Info Day Bucharest
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NEW GENERATION REACTORS: HOW?
DESIGN OF INOVATIVE NEW REACTOR TYPES IS DONE ESSENTIALLY BY USING: -PERFORMANT, STATE OF THE ART CODES FOR MONTE CARLO SIMULATION and -RELIABLE CROSS SECTION LIBRARIES WITH INFO CONCERNING THE DATA PRECISSION -BENCHMARKING Info Day Bucharest
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WASTE PROCESSING: P&T Radiotoxicity of Nuclear Waste:
production of Pu and "minor actinides" (Np, Am,...) by "breeding" (combination of neutron capture and beta decay) production of long-lived radioactive fission products Partitioning: separate and recycle U, Pu Transmutation: "burn" minor actinides (by neutron-induced fission), "transform" long-lived fission products into short-lived or stable isotopes (by neutron capture) requires fast neutrons Info Day Bucharest
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LIBRARIES: WHAT IS THE PRESENT STATUS?
MANY LIBRARIES, GENERALLY CONCORDANT BUT: ZONES WHERE DATA ARE ABSENT OR LARGE (20% or more) UNCERTAINTIES (especially for structural materials but also for MA) REGIONS WHERE DATA ARE DISCREPANT CROSS SECTIONS EXIST BUT DATA PRECISSION AND CROSS INFLUENCE OF DIFFERENT FACTORS (SO CALLED COVARANCE MARIX) INSUFFICIENTLY KNOWN OR NOT KNOWN AT ALL Info Day Bucharest
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extrapolations based on previous knowledge
ILLUSTRATION Example 1: large uncertainties in data files due to lack of experimental data extrapolations based on previous knowledge IRMM previous knowledge Info Day Bucharest
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predictions from model codes
ILLUSTRATION Example 2: large uncertainties in data files due to inaccurate experimental data 61Ni(n,p)61Co 2 4 6 8 10 12 14 16 18 20 40 80 120 61 Co: N=24/2.499 MeV; 6.48/-.89: D =1.50 keV N=11/1.682 MeV; 6.85/-.87: N=24/2.499 MeV ; 6.85/-.75: TALYS_0.49 Paul (1953) Cross (1963) Preiss (1960) Qaim (1977) Bahal (1984) Qaim (1984) Viennot Ribansky (1985) Viennot (1991) Molla (1991) Osman (1996) Val'ter (1962) Levkovskiy (1969) IRMM cross section (mb) neutron energy (MeV) predictions from model codes Info Day Bucharest
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NEUTRON DATA: HOW? A NEUTRON SOURCE IS MANDATORY
THERE IS NOT AN ALL PURPOSE NEUTRON SOURCE SUCH FACILITIES ARE HIGH-TECH INSTALLATIONS USSUALLY WITH TRANS- NATIONAL ACCESS Info Day Bucharest
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ILUSTRATION: NEURON FACILITIES IN THE WORLD
LOS ALAMOS OAK RIDGE JAPAN RUSSIA n_TOF (CERN) GELINA (IRMM) VdG accelerators (France, Germany, Belgium, etc.) HIGH-FLUX REACTORS FUTURE: SPIRAL2? Info Day Bucharest
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NEUTRON DATA: FOCUS ON GELINA
IRMM: A TRADITION IN QUALITY NUCLEAR DATA FACILITY, CHARACTERISTICS CAPTURE CROSS SECTIONS TRANSMISSION CROSS SECTIONS FISSION CROSS SECTIONS INELASTIC AND (n,2n) CROSS SECTIONS Info Day Bucharest
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Reference Laboratory for Neutron Physics
Provide European safety authorities and industry with neutron data needed for: the feasibility study of waste transmutation facilities and advanced systems the safety assessment of nuclear installations and the nuclear fuel cycle 7 MV VdG 150 MeV Electron Linac High-resolution neutron cross-section data measurements Facilities: GELINA and VdG exclusively used for neutron production Info Day Bucharest
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Geel Electron Linear Accelerator GELINA:
Continuous energy spectrum, Time-of-flight measurements n L e- 150 MeV U Info Day Bucharest
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GELINA: a powerful neutron source
High-energy electron accelerator Electron-neutron conversion target 150 MeV electron accelerator (10 ns, 10 A) pulse compression to 1 ns and 100 A 800 bursts / s uranium target - mercury cooled neutrons / burst Info Day Bucharest
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CERN TOF Facility GELINA
spallation neutron source 24 GeV protons, 3·1013 p/pulse Δt ~10 ns, frequency ~0.4 Hz Pb target: 40 cm x 40 cm diam water moderator Neutron production rate: ~ 2·1016 n/pulse ~ 1016 n/s ~forward directed fixed flight path L: 200 m ~7·106 n/cm per pulse (2.4 s) single user facility, En < 109 eV very high n flux per pulse radioactive targets, rare isotopes GELINA electrons bremsstrahlung neutrons 0.15 GeV electrons, 7.5·1011 e- /pulse Δt = 1 ns, frequency : 800 Hz U target: torus, 3 cm x 30 cm outer diam ( + water moderator ) Neutron production rate: ~ 4·1010 n/pulse ~ 3·1013 n/s ~isotropic several stations with L ~ 10 m m ~3· n/cm2 per pulse (1.2 ms) multi-user facility, En < 10 MeV very high energy resolution, flux ~ 1/3 of TOF in resonance region Info Day Bucharest
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Van de Graaff accelerator
monochromatic neutrons via nuclear reactions e.g.: d n Ti/T Info Day Bucharest
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radiotoxic inventory Typical radiotoxic inventory as a function of time in Sv per metric ton of heavy metal fission products Info Day Bucharest
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radiotoxic inventory contribution from long-lived fission products
Info Day Bucharest
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Nuclear Waste Transmutation
Example: long-lived fission product 129I via neutron capture: 129I ( a) + n 130I (12.4 h) 130Xe (stable) feasibility studies: capture and transmission experiments at GELINA (collab. with CEA) + n 129I - 130I a 12.4 h 130Xe stable Info Day Bucharest
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High Resolution Measurements on 99 Tc at GELINA
Info Day Bucharest
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206Pb(n,g): res. shape analysis
Experiments at GELINA 304 resonances observed (221 in evaluated files) E0, g up to 620 keV (before up to 200 keV ); gn up to 80 keV A. Borella, P. Schillebeeckx Info Day Bucharest
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Inelastic scattering mechanism by which fast neutrons lose energy
energy spectrum in accelerator driven systems (ADS) structural materials (Al,Fe) : criticality coolant materials (Na,Pb) : coolant void effect Info Day Bucharest
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27Al Inelastic Neutron Scattering
Eg= MeV Eg= MeV Info Day Bucharest
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58Ni, Inelastic cross section
L. Olah, DNE, HU C. Borcea, SV, RO L.C. Mihailescu, GH,RO IReS Strasbourg U. and TU Vienna U. Belgrade nTOF collaboration Info Day Bucharest
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207Pb(n,n’g) and (n,2ng) measurements
Mihailescu et al. Rudolf et al. 200 m FP, Gelina fast flux 8 ns FWHM TOF-resol. 4 HPGE (3x 95%, 1x 80 %) Continuous energy up to 20 MeV High resolution at low energy Info Day Bucharest
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207Pb(n,n’g) Info Day Bucharest
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209Bi(n,n’g), Deduced total inelastic
Info Day Bucharest
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ROMANIA AND IRMM-NP UNIT
VISITING SCIENTISTS (2 SENIOR RESEARCHERS FROM NIPNE-BUCHAREST AND 2 PROFESSORS FROM BUCHAREST UNIVERSITY) DNE (2 SENIOR RESEARCHERS FROM NIPNE- BUCHAREST) ONE PHD THESIS DONE IN IRMM (GRANT HOLDER) 4 POST-DOCTORAL FELLOWS (NIPNE-BUCHAREST) NEURON MEASUREMENTS, EVALUATIONS AND APPLICATIONS: NEMEA-2 WORKSHOP ORGANIZED BY IRMM AND NIPNE AT BUCHAREST (2004) Info Day Bucharest
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CONCLUSION HIGH QUALITY NEUTRON DATA ARE NECESSARY
COMPLEMENTARITY AND COOPERATION MEASUREMENT-EVALUATION CYCLE ATRACT NEW INSTITUTIONS/PEOPLE COMMUNICATE! Info Day Bucharest
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