JAEA 2 0 1 8 Sym posium on Nuclear Data Developm ent of Active Neutron NDA System Yosuke Toh Nuclear Science and Engineering Center Japan Atomic Energy Agency
JAEA Collaborators Y. Toh 1 , A. Ohzu 1 , H. Tsuchiya 1 , K.Furutaka 1 ,F. Kitatani 1 , M. Kom eda 1 , M. Maeda 1 , M. Kureta 1 , M. Koizum i 1 , M. Seya 1 , J. Heyse 2 , C. Paradela 2 , W . Mondelaers 2 , P. Schillebeeckx 2 T. Bogucarska 3 , J. Crochem ore 3 , G. Varasano 3 , K. Abbas 3 B. Pedersen 3 1 Japan Atom ic Energy Agency 2 Joint Research Centre – Geel 3 Joint Research Centre – I spra This research w as im plem ented under the subsidiary for nuclear security prom otion of MEXT.
JAEA Outline Objectives 1 Active neutron NDA techniques 2 Developm ent of 3 Active-N @ NUCEF Sum m ary 4
JAEA JRC-JAEA Collaboration Action Sheet -1 (2012 - 2015) Neutron Resonance Densitometry (NRD) For characterization of debris of melted fuel Action Sheet -7 (2015 – 2017) Developments of active neutron NDA techniques for Nuclear Non-Proliferation, Security and Safety
JAEA JRC-JAEA Collaboration: AS-7 Investigate and demonstrate active neutron NDA technologies to quantify special nuclear materials and other elements in the presence of high radioactive materials
JAEA Experimental facilities NUCEF-BECKY @ Tokai GELI NA @ Geel TRP-PCDF @ Tokai PUNI TA @ I spra
JAEA Active neutron NDA techniques Neutrons can lead to nuclear fission and neutron capture reactions w hich produce gam m a-rays and DDA neutron. （ Differential Die- aw ay Analysis ） Fission 2 3 9 Pu effective neutron Stable DGA nucleus Delayed Nuclear （ Delayed Gam m a- gam m a-ray fission ray Analysis ） Unstable Excited Ratio 2 3 5 U/ Pu Neutrons Stable nucleus state nucleus U NRTA （ Neutron Resonance Transm ission Analysis ） N Specific Nuclei of DT neutron SNA,MA generator Excited PGA state Neutron Sodern Genie3 5 Stable （ Prom pt Gam m a- capture nucleus 2 × 1 0 9 ray Analysis ） reaction Prom pt gam m a-ray neutrons/ s Explosive,Neutron 1 4 MeV poison
JAEA Ideal concept design of NDA system Delayed Gamma-ray Differential Die-away Analysis （ DGA ） Neutron S hielding Analysis （ DDA ） and Transportation Neutron Detector Gamma-ray Bank Detector Transmit t ed Neut rons A Li-glass Neutron Detector （ Inside ） Neutron Resonance Transmission Analysis Gamma-ray （ NRTA ） Detectors Prompt Gamma-ray Analysis （ PGA ） S amples to be Verified Neutron reflector A D-T Pulsed Neutron S ource
JAEA Development of Active-N(DDA,PGA) Monte Carlo simulation (PHITS, MVP, MCNP) Radi diati tion on shie ields for r licens censing ng pr proc ocess DDA Neut eutron n PGA reflector or Active-N-II Neut eutron n moder erator Neut eutron n & gamma-ray （ DDA,PGA,NRT RTA,DGA ） shie ields Dev evel elopmen ents of det etect ectors Neut eutron n flux ux Collim limator distrib ibutio ion Correc ection n met etho hods
JAEA Simulation studies of DDA and PGA Simulation studies for prototype system (Active-N) which can measure DDA and PGA have been performed by MCNP (MVP and PHITS). DT neutron Detector bank Sam ple source SUS Air Air Polyethylene
JAEA Differential Die-away Analysis(DDA) Differential Die-Away (DDA) is an active neutron interrogation technique DDA measurements Neutron signal counts DT neutron source Detector bank Interrogation neutron Neutron counts 200L Drum Fission neutron （∝ fissile ） Neutron die-away time 1/e Shields Elaspsed time Fission Interrogation neutron neutron In DDA, a neutron detector measures the time-dependent decay of neutrons from the sample.
JAEA Optimization of moderator thickness DDA ： Simu DDA mulation sp spectra 1.E+10 Pu-239 15.0g Pu-239 10.0g unts 1.E+8 Pu-239 5.0g Pu-239 1.0g n coun Det etect ector bank nk Pu-239 0.5g Pu-239 0.1g 1.E+6 utron c DT DT neut neutron s n sour urce ce Pu-239 0.01g blank 1.E+4 Neut 1.E+2 1.E+0 0 200 400 600 800 1000 Ela lapsed tim ime ( μ sec ec) Moderator thickness ss 500% cm ） 3cm ion Optimu Op mum t m thickn kness ss ency （ for 3cm detectio 400% 4cm 5cm 5cm ～ 6cm 6cm 5cm 300% 6cm ive d Sam ample efficienc 7cm 200% lativ Rela 8cm 100% 9cm 10cm Moderator 0% 239 Pu 239 Pu 0.01g 0.1g 0.5g 1g 5g 10g 15g
JAEA Neutron Resonance Transmission Analysis （ NRTA ） Total cross sections(JENDL-4) Each nuclide has resonances at specific 240 Pu 242 Pu U & Pu energies. Neutron Sample Detector Pulsed Neutron Transmitted MA neutrons Resonances can be used to identify & quantify SNM and MA.
JAEA Simulation model of a compact NRTA system Neutron detector ( 6 Li-glass detector) Polyethylene + Stainless steel (SUS) Boron-Polyethylene + Pb DT neutron source Sample Air y [cm] Polyethylene Neutrons Boron-Poly. SUS Flight path length: 5 m Al Pb The fluxes of neutrons and γ rays SUS Polyet hylene Neutron and γ ray fluxes: 1cm or 3cm
JAEA Effects of a pulse width of a neutron beam Pulse widths DT tube : 10 us 30 GWd/t spent fuel (t 1cm) Electron linac : 1 us 238 U 240 Pu 239 Pu 241 Pu 238 Pu 235 U (6.7 eV) (0.3 eV) (1.03 eV) (4.28 eV) (18.6 eV) (8.76 eV) 238 U (6.7 eV) 242 Pu (2.6 eV) 239 Pu, 240 Pu, 242 Pu and 238 U can be measured with DT tube All Pu, 235 U and 238 U can be measured with a pulse width (<1 us)
JAEA Nuclear data of Radioactive Isotopes Se-79 is important for long- term safety assessment of a geological repository JENDL DL-4. 4.0 NRTA TA (and nd NRCA) ca can’t n’t be e us used ed to mea easur ure Se-79 79
JAEA NRTA measurements of Cu-63 NRTA RTA s spect ectra of f Cu-63 63 ー Exp. ー Cal. Large d e discr crep epanc ncy Γ n ＝ 0.59±0.02eV ー Exp. ー Cal. Optim ization of Γ n Γ n ＝ 0.899±0.005eV
JAEA NRTA measurements of Cu-63 Calculation (Areal density) C/E = Experiment (Areal density) C/E <±2% Old Γ n ＝ 0.59±0.02eV New Γ n ＝ 0.899±0.005eV
JAEA Decision tree of HE, CW, n poisons W P ： W hite phosphorus m unitions H ： Sulfur m ustard gas VX ： VX gas ( nerve agent) CG ： Phosgene GB ： Sarin ( nerve agent) CK ： cyanogen chloride HE ： High Explosive HN ： Nitrogen m ustard gas L ： Lew isite gas FM ： Sm oke Active-N system can detect all of these elements.
JAEA Detection of Nitrogen gammas (HE) • Capture cross section small (s g (25.3meV)~80mb) • Includes high-energy gamma rays (e.g. 10,829keV) 53 Cr, 8 8 8 4 keV 5 6 Fe, 7 6 3 1 + 7 6 4 6 keV 1 4 N, 1 0 ,8 2 9 keV w / : 3 3 0 m in. w / o : 1 4 0 m in. High S/N ratio in the high energy region
JAEA Summary Active neutron NDA techniques have been studied and im proved in JRC-JAEA collaboration: AS-7 . Developm ents of Active-N( DDA,PGA) has been com pleted successfully in Phase I and Phase I I has started. Nuclear data is still lacking.
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