A CHALLENGE FOR SUSTAINABLE, CLEAN ENERGY C.Borcea NEUTRON DATA A CHALLENGE FOR SUSTAINABLE, CLEAN ENERGY C.Borcea Info Day Bucharest
OUTLOOK INTRODUCTION NEUTRON DATA (ND): WHY AND HOW ND AT IRMM NP CONCLUSION Info Day Bucharest
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
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
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
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
NUCLEAR ENERGY KEY ISSUES SAFETY (keff) SUSTAINABLE (BU, CLOSED CYCLE) WASTE (P&T) NONPROLIFERATION Info Day Bucharest
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
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
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
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
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: 0.95 N=24/2.499 MeV ; 6.85/-.75: 1.04 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
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
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
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
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
Geel Electron Linear Accelerator GELINA: Continuous energy spectrum, Time-of-flight measurements n L e- 150 MeV U Info Day Bucharest
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 4 1010 neutrons / burst Info Day Bucharest
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/cm2 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 - 400 m ~3·103 - 2 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
Van de Graaff accelerator monochromatic neutrons via nuclear reactions e.g.: d n Ti/T Info Day Bucharest
radiotoxic inventory Typical radiotoxic inventory as a function of time in Sv per metric ton of heavy metal fission products Info Day Bucharest
radiotoxic inventory contribution from long-lived fission products Info Day Bucharest
Nuclear Waste Transmutation Example: long-lived fission product 129I via neutron capture: 129I (1.6 107 a) + n 130I (12.4 h) 130Xe (stable) feasibility studies: capture and transmission experiments at GELINA (collab. with CEA) + n 129I - 130I 1.6 107 a 12.4 h 130Xe stable Info Day Bucharest
High Resolution Measurements on 99 Tc at GELINA Info Day Bucharest
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
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
27Al Inelastic Neutron Scattering Eg=1.0145 MeV Eg=0.8438 MeV Info Day Bucharest
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
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
207Pb(n,n’g) Info Day Bucharest
209Bi(n,n’g), Deduced total inelastic Info Day Bucharest
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
CONCLUSION HIGH QUALITY NEUTRON DATA ARE NECESSARY COMPLEMENTARITY AND COOPERATION MEASUREMENT-EVALUATION CYCLE ATRACT NEW INSTITUTIONS/PEOPLE COMMUNICATE! Info Day Bucharest