Organisation for the Prohibition of Chemical Weapons. Inspectorate

Transcription

1 Organisation for the Prohibition of Chemical Weapons Inspectorate 1

2 . OPCW APPROVED NON-DESTRUCTIVE EVALUATION (NDE) METHODS AND EQUIPMENT Content 1. Introduction 2. The NDE method abilities, advantages and limits 3. New NDE tasks - new NDE equipment requirements 4. Suggested improvements of the NDE equipment 5. Summary 2

3 ad 1 Introduction Non-Destructive Evaluation (NDE) methods During Preparatory Commission activities the group of experts recommended application of Non-Destructive Evaluation methods to support inspection activities in CW Storage Facilities (CWSF) - where modern, well-defined Chemical Weapon items are stored NDE techniques were planned to be used for: fast screening - to distinct between conventional and chemical munitions non-intrusive verification/determination of content of munitions and other inspected items fill level determination in bulk items (containers, tanks, etc.) To fulfil above tasks, the following NDE methods were selected, recommended and consequently approved: 1. The Ultrasonic Testing (UT) - Ultrasonic Pulse Echo (UPE) method 2. The Hydrogen Concentration Measurement (HCM) method 3. The X-ray Radiography (X-ray) 4. The Neutron Induced Prompt Photons Spectroscopy (NIPPS/PINS) 5. The Acoustic Resonance Spectroscopy (ARS) 3

4 ad 1 Introduction NDE methods - principles of operation 1. The Ultrasonic Testing (UT) - Ultrasonic Pulse Echo (UPE) Technique is based on the measurement of the propagation time of ultrasonic pulses (range MHz, in the OPCW applications 5-10 MHz), which reflect off solid/liquid boundaries. This method, widely used in industry, was adapted for CWC verification purposes. 2. The Hydrogen Concentration Measurement (HCM) Technique is based on the valuation of hydrogen concentration in the inner volume of munitions or containers: this utilises the ability of hydrogen atoms to effectively moderate high energy neutrons into thermal (slow, low energy) neutrons is used, after moderation neutrons are detected by a selective detector, which is sensitive only to thermal neutrons, the counting rate of detected thermal neutrons is proportional to the density of hydrogen atoms in the material inside the object. 4

5 ad 1 Introduction NDE methods - principles of operation -cont. 3. The X-ray Radiography Technique is based on the well-known radiographic technique and is an adaptation of the typical industrial X-ray system to the CWC requirements: X-rays emitted from X-ray tube are directed into and through a tested object (munitions, container), due to different thickness, physical density and atomic number of materials and structures inside the object, X-rays are more or less attenuated, as a result, the penetrating radiation forms a sharp image on the X-ray sensitive film or is directly readable on screen of Real Time Imaging System. 4. The Neutron Induced Prompt Photons Spectroscopy (NIPPS) Technique was originally developed for non-destructive monitoring of CW munitions in the USA and Russian stockpiles and later was adapted for CWC verification purposes Method is based on the detection of characteristic gamma radiation which is emitted after inelastic neutron scattering or after thermal neutron capture by the involved atomic nucleus Analysis of collected gamma spectra allows the valuation of chemicals elements in shells, bombs and containers 5

6 ad 1 Introduction General characteristic of the NDE methods The higher accuracy and reliability of the method, the more expensive and complicated the equipment, as well as the more time consuming measurement. The UT/UPE - the fastest and simplest, but its results are often uncertain. The HCM - more universal and reliable, but results relative only! The X-ray technique - direct and reliable, equipment bulky and more expensive, measurements are time consuming. The NIPPS/PINS technique - the most precise and dependable results, but equipment is sophisticated, expensive and measurements are time consuming. Sampling and analysis is the most reliable tool for verifying of the identity of contents of inspected items but it is expensive, time consuming and, according to actual policy of the OPCW, its use during inspections is strictly limited. The usage of the NDE methods during inspections is not as strictly limited as sampling and analysis. Under specific circumstances the results of NDE measurements can be nearly as reliable as results of chemical analysis (i.e., approx % reliability of the NIPPS/PINS system). 6

7 ad 1 Introduction Three different types of the NDE equipment are actually in the OPCW possession: Ultrasonic Testing (UT) - Staveley Sonic 137 and Quantum QFT-1 Plus Hydrogen Concentration Measurement (HCM) - Eberline GmbH HCM Set X-ray Radiography (X-ray) - Andrex Smart 300 X-ray Set Other NDE equipment: Neutron Induced Prompt Photons Spectroscopy (NIPPS) - Portable Isotopic Neutron Spectroscopy Chemical Assay System (PINS); The OPCW PINS equipment was recently sold back to the USA Acoustic Resonance Spectroscopy (ARS). ARS equipment is not in the OPCW possession - commercial version of the equipment is not ready. OPCW operators are certified only in usage of first three (UT/UPE, HCM, X-ray) techniques 7

8 ad 2 The NDE methods abilities, advantages and limits The Ultrasonic Testing (UT/UPE) technique 1. Abilities Wall thickness measurement (shells, containers, etc.) Detection of liquid filling (versus empty/solid filling) in shells, bombs, containers, etc. Determination of liquid fill level in bulk items And under favourable circumstances: partial identification of internal structure of munitions, identification of a type of CW Agent present inside tested object. 2. Advantages Short time of measurement The UT/UPE equipment is light, portable and not expensive Very convenient for fast screening of munitions in storage depots Combined use of the UT/UPE technique with HCM or X-ray Radiography can increase accuracy and reliability of the HCM and the X-ray measurements 3. Limits The UT/UPE technique fails in case of: double wall items (including most of binary munitions), polymerised (even partially) content of a container/shell. 8

9 ad 2 The NDE methods abilities, advantages and limits The Hydrogen Concentration Measurement (HCM) technique 1. Abilities Distinction between chemical and conventional munitions (due to the considerable difference between the hydrogen concentration in CW Agents and explosive, smoke or incendiary materials), Possible identification of the type of CW Agent inside the investigated item (using calibration curve prepared for particular type of object and, if necessary, the UPE equipment for defining physical state of the filling), Determination of the fill level in bulk containers (on a basis of different response from air and hydrogen content filling) 2. Advantages Short time of measurement Reliable results of investigation The HCM equipment is light, readily portable and not expensive Very convenient for fast screening of munitions in storage depots Possible detection of chlorine (with CDS System) Double wall or polymerised content does not affect results of the HCM measurements 9

10 ad 2 The NDE methods abilities, advantages and limits The Hydrogen Concentration Measurement (HCM) technique - cont. 3. Limits Technique is not suitable for estimation of a physical state of the content of the investigated object The necessity of use of a fast neutron radioactive source Cf-252 (activity ~ MBq, i.e. ~1-10x10 5 ns -1 ) used activity is low and does not constitute a radiation hazard under normal operating conditions, but certain limits on the transportation conditions of the equipment Presence of chlorine makes the HCM results uncertain implementation of additional independent technique of the chlorine detection is advisable (i.e. CDS - Chlorine Detection System - supplementary equipment for the HCM Set; CDS is not in the OPCW possession yet). 10

11 ad 2 The NDE methods abilities, advantages and limits The X-ray Radiography 1. Abilities The radiographic inspection detects interior structure of munitions: wall thickness and contours surface of liquid filling, different compartments of the munitions body or structure characteristic for chemical munitions All these observation give evidence of the nature of the inspected object (chemical/conventional munitions, fill level in containers, etc.). 2. Advantages Very suitable for verification of: the old chemical/conventional munitions, rusted, deformed or unmarked munitions, items over-packed in wooden or thin metal boxes and containers (if not removable). No restrictions in air/road transportation, as equipment (when switched off) does not contain any radioactive source 11

12 ad 2 The NDE methods abilities, advantages and limits The X-ray Radiography - cont. 3. Limits Radiography can not be used to reveal the nature of chemical elements inside the tested object If munitions is homogeneously and fully filled with an unknown material, the recognition of the shell content and type of the munitions (chemical or conventional) is difficult Radiography is not suitable for reliable differentiate between solid filled and empty munitions Main disadvantage of the X-ray equipment is its high radiation output - work with such an equipment is potentially very dangerous Users must follow strictly all the rules of the Radiation Protection! 12

13 ad 2 The NDE methods abilities, advantages and limits The Neutron Induced Prompt Photons Spectroscopy (NIPPS/PINS) 1. Abilities NIPPS System is able to estimate the containers (shell, bomb, etc.) content and to distinguish clearly and legibly between conventional and chemical munitions. For chemical munitions the NIPPS system is also able to distinguish between different types of CW Agents (blister, nerve, WWI Agents), as well as to indicate a presence of particular CW compound within one group of CW Agents (i.e., VX, GA and GB within nerve agents). For old and unknown chemical munitions the NIPPS system is able to detect key elements of a shell content and give reliable indication of the nature of the shell filling. Measurements can be made not only in separate munitions of any kind, but also in munitions packed in wooden or metal boxes and containers, or in pipelines, tubes or vessels thorough which liquids are pumped. NIPPS analysis is a powerful tool not only for final confirmation of declarations made during routine inspections after first simpler NDE methods (UPE, ARS, HCM) have been used, but also for final detection of Scheduled chemicals during a challenge inspection. 13

14 ad 2 The NDE methods abilities, advantages and limits The Neutron Induced Prompt Photons Spectroscopy (NIPPS/PINS) - cont. 2. Advantages All parts and transportation boxes are easily portable by 2 people and system can be installed within one hour. A measuring time is acceptable (10-30 min for a 155 mm shell), hardware and software are user-friendly. Results are reliable, close to reliability of chemical analysis Visualisation of collected spectra is possible, what can significantly increase reliability of the results evaluation. 3. Limits The NIPPSequipment is sophisticated and expensive. PINS fast neutron radiation source (Cf-252, activity ~1x10 8 Bq) is reasonably strong: source requires a special shielding transport container and put the limits on conditions of transportation of the PINS equipment, stronger radioactive source can cause a radiation hazard during work and the users must follow strictly all the rules of the Radiation Protection. The High Purity Germanium detector (HPGe) used in the NIPPS system is expensive, easy to damage, and, has to be cooled to temp -196 O C; when liquid nitrogen is used for cooling, exploitation of the system can be limited (availability of liquid nitrogen on the mission). 14

15 ad 3 New NDE tasks - new NDE equipment requirements Non-Destructive Evaluation (NDE) methods - new challenge After six years experience on the implementation of the verification provisions of the CWC: application of the NDE methods for verification of the ISP declarations in CWSF related inspections is strictly limited: only Ultrasonic Testing (UT/UPE) method is used, and only two ISPs allow to use UT/UPE in CWSFs. X-ray radiography was used in ACW missions. HCM and NIPPS methods were never used during real inspection. The NDE investigation methods were used during all the OPCW IAU exercises and last two the OPCW CI exercises. Conclusions: Since PrepCom recommendations to use NDE methods mainly in CWSF inspections, main tasks of the OPCW NDE techniques were moved to IAU, CI and ACW/OCW applications. The OPCW NDE equipment was selected to support CWSF inspection and is not properly configured to support IAU and CI activities. 15

16 ad 3 New NDE tasks - new NDE equipment requirements NDE equipment for IAU/CI - new requirements Possible to use in remote sites/areas Possible to use under field conditions in potentially contaminated areas Easily portable equipment (one-man carry) - two operators should be able to move all elements of the NDE equipment down-range to an investigated site Remote control option is an advantage, Minimum air transportation restrictions (dangerous goods), Exploitation materials low requirements, Ability of direct detection of compounds/elements inside an investigated item is highly desirable 16

17 ad 3 New NDE tasks - new NDE equipment requirements IAU/CI applications - limitations of use of the OPCW NDE equipment 1. Ultrasonic Testing (UT/UPE) According to non-touch policy during IAU/IC missions, there is low ability to use the UT technique 2. Hydrogen Concentration Measurement (HCM) Presence of chlorine inside an investigated object makes results of measurement uncertain 3. X-ray radiography Equipment portable, but heavy and bulky High radiation output - large safety zone and high radiation safety requirements 4. Neutron Induced Prompt Photons Spectroscopy (NIPPS) The most useful investigation tool, but Equipment is not in the OPCW possession 17

18 ad 4 Suggested improvements of the NDE Equipment Suggested improvement of the NDE equipment when used during IAU/IC and ACW/OCW missions 1. The Hydrogen Concentration Measurement (HCM) equipment To overcome the weakness of the HCM system of non-confident identification of unknown filling (possible presence of chlorine): Purchase the Chlorine Detection System (CDS) and combine it with existing HCM system expected cost of one set: 30,000-50,000 Euro time for operators and procedures preparation: 6-12 months The CDS system would allow the operator to positively identify the chlorine concentration in the object and apply correction factors to the HCM investigation results 18

19 ad 4 Suggested improvements of the NDE Equipment 2. The X-ray Radiography Purchase, for use in remote, possibly contaminated areas, a one-man portable X-ray Set, consists of portable X-ray unit, Real Time Imaging System, Computer and Remote Control System expected cost of one set: 50,000-70,000 Euro time for operators and procedures preparation: 1-3 months Expected advantages of a new X-ray system when used during IAU/CI missions: Possesses Andrex Smart 300 X-ray Set Equipment heavy full set ~500 kg Proposed one-man portable X-ray Set Equipment light full set ~100 kg Equipment bulky 11 boxes, cargo requir. 3m 3 Equipment compact 4 boxes, cargo reguir. 1m 3 High radiation output (continuous emission) Large safety zone High requirements of radiation safety Cable connections risk of cross-contamination Low radiation output (pulse emission) Limited safety zone Moderate requirements of radiation safety Remote control lower risk of contamination 19

20 ad 4 Suggested improvements of the NDE Equipment 3. The Neutron Induced Prompt Photons Spectroscopy (NIPPS) Purchase a new NIPPS system, what will significantly increase the OPCW NDE investigation abilities during IAU/CI missions expected cost of one set: 180, ,000 Euro time for operators and procedures preparation: 3-6 months The new NIPPS system, currently under evaluation, does not have weaknesses of the previous NIPPS system in the OPCW possession - PINS: system is equipped in neutron generator and does not contain any radioactive source, instead of liquid nitrogen, electrically powered cryogenerator is used for the HPGe detector cooling, no user licence limitations. Additionally, a new NIPPS system independently collects and evaluates three different types of gamma spectra, what increases equipment sensitivity and confidence of obtained results. When possessed, the NIPPS system will be the first OPCW NDE equipment with ability to detect and identify nature of unknown filling with reliability close to the chemical analysis. 20

21 ad 5 Summary Efficiency of the NDE methods is higher when combination of different NDE techniques is applied Direct ability of the UT/UPE systems to determine liquid or solid contents of the investigated object significantly increases accuracy and reliability of results obtained from HCM and X-ray measurements Determination of a fill level with UT/UPE technique can be supported by HCM method in case of partially polymerised contents of tanks or containers During verification activities in large munitions storage is highly recommended to use simpler NDE methods (UPE, HCM) for munitions screening, and final confirmation of declaration by NIPPS system examination of selected munitions items X-ray technique supplements NDE measurements in case of old, bad quality or over-packed munitions 21

22 ad 5 Summary Applications of the OPCW NDE techniques CW storages - fast and reliable screening of a large amount of inspected items and confirmation of munitions and bulk containers contents on-site Investigation of Alleged Use - to check battle fields and other suspicious places for the presence of CW Agents Challenge Inspections - at declared and undeclared sites to investigate munitions, bulk containers and production plants for presence/absence of Schedule 1 chemicals High performance and abilities of invented NDE techniques made possible their wider applications and efficient use in other CW-related (CWPF, Schedule 1) and Schedule 2 inspections for confirmation of absence of Schedule 1 chemicals 22

23 . Questions? Comments? 23

24 Organisation for the Prohibition of Chemical Weapons Thank you for your attention Inspectorate

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