1. A CHALLENGE FOR SUSTAINABLE, CLEAN ENERGY C.Borcea
NEUTRON DATA
A CHALLENGE FOR SUSTAINABLE, CLEAN ENERGY
C.Borcea
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2. OUTLOOK INTRODUCTION NEUTRON DATA (ND): WHY AND HOW ND AT IRMM NP
CONCLUSION
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3. 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
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4. 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
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5. 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
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6. 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.
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7. NUCLEAR ENERGY KEY ISSUES
SAFETY (keff)
SUSTAINABLE (BU, CLOSED CYCLE)
WASTE (P&T)
NONPROLIFERATION
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8. 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
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9. 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
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10. 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
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11. 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
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12. 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
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13. 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
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14. 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?
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15. 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
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16. 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
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17. Geel Electron Linear Accelerator GELINA:
Continuous energy spectrum,
Time-of-flight measurements n L e-
150 MeV U
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18. 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
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19. 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
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20. Van de Graaff accelerator
monochromatic neutrons via nuclear reactions
e.g.: d n 
Ti/T
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21. radiotoxic inventory
Typical radiotoxic inventory as a function of time
in Sv per metric ton of heavy metal
fission
products
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22. radiotoxic inventory contribution from long-lived fission products
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23. 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
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24. High Resolution Measurements on 99 Tc at GELINA
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25. 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 ); gn up to 80 keV
A. Borella,
P. Schillebeeckx
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26. 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
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27. 27Al Inelastic Neutron Scattering
Eg= MeV
Eg= MeV
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28. 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
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29. 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
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30. 207Pb(n,n’g)
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31. 209Bi(n,n’g), Deduced total inelastic
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32. 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)
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33. CONCLUSION HIGH QUALITY NEUTRON DATA ARE NECESSARY
COMPLEMENTARITY AND COOPERATION
MEASUREMENT-EVALUATION CYCLE
ATRACT NEW INSTITUTIONS/PEOPLE
COMMUNICATE!
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