A Proposal of Nuclear Materials Detection and Inspection Systems in Heavily Shielded Suspicious Objects by Non-destructive Manner.

Transcription

1 Magic Maggiore Technical Reachback Workshop 15 min. (March 28-30, 2017, JRC Ispra, Italy) A Proposal of Nuclear Materials Detection and Inspection Systems in Heavily Shielded Suspicious Objects by Non-destructive Manner Japan Atomic Energy Agency(JAEA) Integrated Support Center for Nuclear Nonproliferation and Nuclear Security (ISCN) Mitsuo KOIZUMI Collaboration of Japan Atomic Energy Agency (JAEA) National Institute for Quantum and Radiological Science and Technology (QST) Joint Research Center (JRC) Supported by Ministry of Education, Culture, Sports, Science and Technology Japan (MEXT)

2 Contents 1. Introduction 2. Secure Detection of Heavily Shielded Suspicious Object 3. Interior Inspection of NMs Part taken out from the Heavily Shielded Objects 4. Summary 1

3 1. Introduction NM : Nuclear Material 2

4 Nuclear Materials under/out of Regulatory Control NM Under Regulatory Control Out of Regulatory Control Situation NMs in nuclear facilities (under control of competent authority) In IAEA member states, NMs are under IAEA safeguards Smuggled NMs (out of control of competent authority) Under nuclear security policy of each state 3

5 NMs Terrors Type RDD Radiological Dispersal Device Nuclear Bomb Other High Radiation Emission Objects Purposes / NMs Purposes:Killing people, causing disruption NMs, RIs :High radiation toxicity isotopes (α-emitters etc.) Purposes:Mass destruction NMs: Special nuclear materials ( 235 U, 239 Pu) Purpose:Insensible high radiation exposure NMs:NMs in criticality(high neutron emission) (JCO type criticality assemblies) RIs: High gamma-ray radiation We need to know the purposes of detected objects for safe handling. 4

6 A Scheme of Strengthening Nuclear Security for NMs out of Regulatory Control Detection Secure Detection Systems of NMs Airports, Harbors, Other places NMs out of Regulatory Control Nuclear Forensic Nuclear Forensics Analytical Systems NF Laboratories Handling of Detected Objects NMs taken out from containers Interior Inspection Systems Dismantlement Systems Adequate Places (Airports, apparent Harbors identification etc.) to NM 5

7 An Example of Heavily Shielded Objects (HSO) containing NM (Just a pure black area by X-ray scanning) Neutron Shield +Neutron Absorber (NM+Mixtures) Heavy Shield (Metal) Heavy Shield (Metal) Neutron Shield Neutron Absorber Shield of gamma-rays from NM / gamma-rays from neutron absorption by surrounding material Moderation of neutrons emitted from NM (inside) / neutrons interrogated from outside Absorption of thermal neutrons 6

8 Present X-ray Scanning Systems for Cargo Containers in Nuclear Security X-ray Scanning Backscatter X-ray imaging Transmission X-ray imaging Purposes Clear imaging for light elements For detection of car and truck bombs / explosives, plastic weapons, and other organic threats / illegal drugs, etc. Imaging for heavy elements For detection of heavy metal items for hiding illegal materials in cargo / heavy weapons etc. 7

9 Present X-ray Cargo Container Scanning System Real Time Backscatter X-ray Imaging Transmission X-ray Imaging ROI (Region of Interest) Imaging with moving 8

10 A Combined Use of X-ray Scanning Systems + Passive Radiation Detectors Not sufficient for secure detection of NM in heavy metal items (heavily-shielded NM) 9

11 2. Secure Detection of Heavily Shielded Suspicious Object HSO MGB MGS ERL LCS NRF NDA(D) ROI Heavily Shielded Object Monochromatic Gamma-ray Beam Monochromatic Gamma-ray Source Energy Recovery Linac Laser Compton Scattering Nuclear Resonance Fluorescence Non-destructive Assay (Detection) Region of Interest 10

12 A Proposal of Secure Detection System of NMs in HSO A combined system X-ray Scanning System + An NRF-based NDD System using Intense MGB X-ray Scanning System An NRF-based NDD System using Intense MGB For detection of suspicious objects (ROI) in cargo containers Pin-point scanning of ROI for detection of NMs (NRF gamma-ray signals of NMs) MGB: Monochromatic Gamma-ray Beam NRF: Nuclear Resonance Fluorescence NDD: Non-destructive Detection 11

13 A Future ERL-LCS Monochromatic Gamma-ray Source Next Generation ERL (350 MeV) 3 loops ~ 25 m Laser Enhancement Cavity 350 MeV electrons High Power Laser Oscillator Electron Beam=350 MeV, 10 ma LCS Gamma-ray (2-3 MeV) ØFlux ~ 1x10 13 ph/s ØΔE/E ~ 0.1% 12

14 Laser Compton Scattering Electrons A Explanation of NRF-based NDA of NM using MGB (Selective NRF Activation of Nuclide) Laser gamma-rays Monochromatic ( & tunable) gamma-ray beam MGB Shielding Material Hidden NM ( 239 Pu) Nuclear Resonance Fluorescence NRF Emission Gamma-rays Detector R. Hajima et al., J. Nuclear Science and Technology (2008) 13

15 NRF Emission Gamma-rays Interrogation Gamma-rays :High Intensity MGB Interior Inspections of HSO by Interrogation of MGB Transmission Gamma-rays Neutron Shield+ Neutron Absorber (NM+Mixtures) Heavy Shield (Metal) Interrogation Gamma-rays (HSO) NRF Emission Gamma-rays Transmission Gamma-rays Bring information of NMs in HSO -Rough characterization of NMs by interrogations of several gamma-rays with specific energies of NM isotopes Bring information of detailed interior structure of HSO -CT imaging with intense monochromatic high-energy gamma-rays 14

16 Rough Characterization of NMs inside of HSO by Interrogation of MGB NRF emission gamma-rays from the isotope of interest (i) Neutron Shield+ Neutron Absorber (NM+Mixtures) (HSO) Heavy Shield (Metal) Interrogation gamma-rays with tuned energy of isotope of interest (i) By changing energy of interrogation gamma-rays tuned to the resonance energy of certain isotope of U/Pu, we are able to count NRF emission gamma-rays from the all isotope of U/Pu. With having counts of NRF emission gamma-rays of all isotopes of U/Pu, we can have information of U/Pu isotopic composition of NM inside the HSO. (Rough characterization of NMs) 15

17 CT Imaging with Intense Monochromatic High-Energy Gamma-rays Detailed information of inner structure of the object Essential for safe dismantlement Gamma-ray Detector Inner Structure of Thick Metal Container Transmission Gamma-rays (HSO) H. Toyokawa, NIMA 545, 469(2005). Interrogation Gamma-rays of high energy; well penetrate into material 16

18 An NRF-based NDD System using Intense MGB For secure (pin-point) detection of NM hidden behind heavy-shield in freight cargo containers Nuclear Material in Heavy Shield 2.4 m Cargo Container 12.2 m Gamma-ray Detectors Next Generation ERL (350 MeV) 2.6 m Moving High Power Laser Oscillator Laser Enhancement Cavity 40Ft Container Max. Weight:30.5 tons 17

19 A Picture of Actual Application of the Proposed System for Secure Detection of NMs (A Combined System of X-ray Scanning with NRF-based NDD) A tunnel for freight container trailers ~15 m ~15 m X-ray Scanning System (Present) To Interior Inspection 1 When X-ray scanning system does not find any ROI in the freight container, then the trailer skips over the NRF based NDD system. 2 When X-ray scanning system finds ROI in the freight container, the trailer is moved to NRF-based NDD system. 3 When signals of NMs are detected, the trailer is moved to interior inspection of detected objects ~20 m NRF-based NDD System using Intense MGB ~35 m 18

20 3. Interior Inspection of NMs Part taken out from the HSO DDA DGS NRTA PGA Differential Die-away Analysis Delayed Gamma-ray Spectroscopy Neutron Resonance Transmission Analysis Prompt Gamma-ray Analysis 19

21 Inspection Procedures after Detection of Heavily Shielded NMs Process Interior inspection of HSO Inspection / Dismantlement Inspection before opening / dismantlement of the objects - Detailed interior structure - Rough characterization of NMs Dismantlement of HSO (taking NMs part out) Interior inspection of NMs Part Safe (remotely operated) dismantlement of HSO at adequate place for taking NMs part out Inspection of NMs part for further dismantlement - Mixed material(explosives etc.) - Characterization of NMs Further Dismantlement for taking NMs out Further safe (remotely operated) dismantlement for taking NMs Out for nuclear forensics 20

22 Rough Explanation of Interior Inspection of NMs Part by Active Neutron NDA (Active neutron NDA techniques (DDA, DGS, NRTA, PGA)) Interrogation Neutrons A D-T Pulsed Neutron Source Neutrons Gamma-rays NMs + Mixtures DDA Induced Fission Neutrons DGA Delayed Gamma-rays (from Fission Products of Induced Fissions) NRTA Transmission Neutrons PGA Neutron Capture Prompt Gamma-rays 21

23 Rough Explanation of Active Neutron NDA (DDA, DGS, NRTA, PGA) NDA Techniques DDA Differential Die-away Analysis DGS Delayed Gamma-ray Spectroscopy NRTA Neutron Resonance Transmission Analysis PGA Prompt Analysis Gamma-ray Rough Explanation For counting / analysis of induced fission neutrons (to quantify fissile mass) from NMs using difference of die-away time of active pulsed neutrons and induced fission neutrons For counting / analysis of specific high energy delayed gamma-rays after induced fissions caused by interrogation of pulsed neutrons (to obtain ratios of fissile isotopes) For counting / analysis of transmitted neutrons through the NMs part using TOF (time of flight) method for quantification of each isotope of NMs For detection of specific prompt gamma-rays generated by (n, γ) reactions of isotopes (For an example; 14 N (n, γ) 15 N ;detection of 14 N in explosives) 22

24 Proposal of an Active NDA System for Interior Inspection of NMs Part (PGA, DDA, DGS, NRTA) 23

25 5. Summary 24

26 Summary - The existence of NM in a suspicious object (in a shield) have to be securely detected. - Before opening the suspicious object, safety should be confirmed. Proposed Sytems NRF-based NDD System using high energy and high intensity MGB Active Neutron NDA system using a D-T Neutron Source Roles Secure detection of NMs in HSO Inspection of inner (explosion) structure of the HSO Rough characterization of NMs (nuclear bomb or not) in the HSO Investigation of mixtures (explosives, toxic materials) in NMs parts / characterization of NMs 25

27 Thank you for your attention. Acknowledgement This work has been supported by a subsidy for strengthening nuclear security of the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan. 26

28 ERL-LCS Demo. System for Future ERL-LCS MGS Generation of High Intensity LCS Monochromatic X-rays : Demonstrated With the LCS Demo. System in March 2015 at KEK Tsukuba (Japan) Electron Gun Injector Experiment Rooms Energy Recovery Linac (Super-Conducting Cavity) (9-cell x 2 cavity) 20 MeV electron s LCS Demo. System High Power Laser Oscillator LCS Gamma -rays Laser Enhancement Cavity Basic Technology Demonstration (Electron Beam = 20 MeV, ma) ØLCS X-ray (~ 6.9 kev) Flux ~ 1x10 9 ph/s/ma ØΔE/E ~0.5% 27

29 Characteristic points monochromatic gamma-rays energy tunable gamma-rays high intensity gamma-rays good directivity gamma-rays Characteristic Points of ERL-based LCS MGS gamma-rays with deep penetrability(*) Advantages for inspection / detection Interrogation of gamma-rays within pin-point energy region - Avoiding unnecessary excitation or absorption - Useful for reduction of BGs and obtaining higher accuracy Interrogation of gamma-rays with tunable energies for nuclides in targets - Selection of nuclide by gamma-ray energy in targets - Makes selective measurements possible Interrogation with high intensity - Higher probabilities of reactions to be interrogated - Makes very fast measurements with higher accuracy (even for measurements of low concentration elements) Interrogation within very limited direction - Avoiding attenuation of interrogation X-/gamma rays -Gives measurements freedom for target distance from the source Interrogation with deep penetration -Deep penetration into heavy material reaching to the target isotopes Selective nuclide detection Pin-point detection * For MeV class gamma-rays 28