iaea international atomic energy agency industrial radiography setting the scene richard van...
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IAEAInternational Atomic Energy Agency
Industrial RadiographySetting the Scene
Richard van Sonsbeek
HSQE Manager Applus RTD
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Industrial Radiography
• A method of Non-Destructive Testing
• Radiation sources:• Radioactive sources• X-ray tubes• Linear accelerators
• Location:• Shielded enclosures /
Radiation Bunkers• In the field / customer site• Onshore / offshore
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Industries that apply RT / NDT
• Petrochemical Plants• Transport Pipelines• Power Generation • Offshore industries • Aerospace industries • Military defense
• Marine industries • Waste Management• Automotive industries • Manufacturing
industries• Transport industries
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Classification of “exposure devices” according to their mobility
Class P Portable exposure container, designed to be carried by one or more persons. The mass of a Class P container does not exceed 50 kg.
Class M Mobile, but not portable, exposure container designed to be movedeasily by a suitable means provided for the purpose, for example atrolley.
Class F Fixed, installed exposure container or one with mobility restricted to theconfines of a defined working location, such as a shielded enclosure.
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Categorization of “exposure devices” according to the way the source is exposed
Category I The source is not removed from the exposure container for an exposure. The source is stored at the center of a block of shielding material. A portion of the shielding can be removed, or the shielding or source is moved to expose the source.
Category II The source assembly is mechanically projected out of the container and travels along a guide tube projection sheath to the exposure head. The projection is hand or motor driven by the radiographer. The sourceassembly is usually moved by a cable.
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Class P, Category I Exposure Device
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Category II Exposure Device
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Class P, Category II Exposure Device
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Class M, Category II Exposure Device
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Gamma Radiography Exposure Device
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Relevant Standards
• ISO 3999• Radiation protection - Apparatus for industrial gamma radiography -
Specifications for performance, design and tests
• IAEA-SSR-6 • Regulations for the Safe Transport of Radioactive Material
• ISO 2919• Radiation protection – Sealed radioactive sources – General
requirements and classification
• IAEA SSG-11• SSG-11: Radiation Safety in Industrial Radiography
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Radioactive sources – Energy and Thickness
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Radioactive Sources – Activities and Dose Rates
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X-ray Radiography Equipment
• Typical specification:• 300 kVp• 6 mA• Dosisrate (@ 1 m) 6 tot 20 Sv/h
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X-ray crawler
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Linear Accelerator
Digital Radiography
Radiographic image = x-ray image (film photography)
RTR = Real Time Radiography = direct x-ray image
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RTD RAYSCAN
Characteristics: Real time No crawler
Collimated beam Lead shielded system
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High radiation safety!
Spoolbase Production Facility
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Landline
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Collimators
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Diaphrams
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Lead slabs
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Site Radiography – Gamma RadiographyTypical Stages during Normal Exposure
1. Storage of gamma source in storage facility
2. Movement of gamma source from store to vehicle
3. Transport of gamma source in vehicle to field location / client site
4. Movement of gamma source from vehicle to work site
5. Exposure(s) (after set up of equipmenta) Wind-out (gamma source in guide tube) Highest Dose Rate
b) Exposure (gamma source in collimator)
c) Wind-in (gamma source in guide tube) Highest Dose Rate
6. Movement of gamma source from work site to vehicle
7. Transport of gamma source in vehicle to store
8. Movement of gamma source from vehicle to store
9. Go to 1.
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When using databases on individual doses, be aware that in general we are comparing…
Apples Pears
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≠
with
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Differences in average dose per person
Relatively high(er) dose Relatively low(er) dose
Single disciplinary technicians (RT) Multi disciplinary technicians (RT, UT, .)
Only RT technicians included Non RT technicians included
High workload (# films, # hours) Low workload (# films, # hours)
“Mobile” radiography (less shielding) “Fixed” Radiography (more shielding)
Thick objects tested Thin objects tested
High source strength Low source strength
High production requirement Low production requirement
Exposure due to accident Normal exposure
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Controlled Area
IAEAInternational Atomic Energy Agency
A Snapshot of Current Practice ofOccupational Radiation Protection in
Industrial Radiography
WGIR – ISEMIR Richard VAN SONSBEEK1, John C. LE HERON2, Gonzague ABELA3 ,
Francisco C.A. DA SILVA4 , Razak HAMZAH5 , Thomas A. LEVEY6 ,
Matthias PURSCHKE7 , Kamal SAHAIMI8 , Christian LEFAURE9
1Applus RTD; e-mail: [email protected] Atomic Energy Agency, Vienna, Austria; e-mail: [email protected]
3EDF; Saint Denis, France; e-mail: [email protected] of Radiation Protection and Dosimetry; Rio de Janeiro, Brazil; e-mail: [email protected]
5Malaysia Nuclear Agency; Kajang, Malaysia; e-mail: [email protected] Group Inc.; Edmonton, Canada; e-mail: [email protected]
7German Society for Non-Destructive Testing (DGZfP); Berlin, Germany; e-mail: [email protected], Rabat, Morocco, [email protected] consultant; Paris, France; [email protected]
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Background to ISEMIR
• Information System on Occupational Exposure in Medicine, Industry & Research
• There are some areas in medicine, industry and research where radiation uses can lead to significant occupational exposures• Both in normal operations and in accident
situations
• But detailed information at the operational level is lacking
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ISEMIR – the launch
• January 2009, for an initial 3 year period, to help improve occupational radiation protection in targeted areas• 2 Working Groups, initially
• Interventional Cardiology, commenced Feb 2009• Industrial Radiography, commenced Jan 2010
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Working Group Industrial Radiography(WGIR)
From left to right: Christian Lefaure, Francisco Da Silva, Kamal Sahaimi, Gonzague Abela, Richard van Sonsbeek, Matthias Purschke, A. Razak Hamzah, John Le Heron(Thomas Levey is not on the picture)
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Composition of WGIR
Name Region Stakeholder
G. Abela Europe Client
M. Purschke Europe NDT Society
T. Levey North America Operating Company
A. Razak Hamzah Asia Technical Service Organization
K. Sahaimi Africa Training provider
F. Da Silva Latin America Technical Service Organization
R. Van Sonsbeek Europe Operating Company
J. Le Heron Scientific Secretary IAEA
C. Lefaure Consultant IAEA
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Objectives of our effort
Keeping ALARA:
1. the dose due to normal exposure• if normal exposure is justified!
2. the risk of exposure due to accidents• (risk= chance X consequence of accident)
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Agreed Mandate
• To draw an overview picture of the situation concerning occupational exposures and radiation protection of staff in Industrial Radiography (radiographers and other industry and client staff members) all over the world.
• To identify both good practices and shortcomings and define all types of actions (training, managerial, behavioural…) to be implemented for assisting the industry, clients, and regulatory bodies in avoiding exposures to accidents, and implementing the ALARA principle.
• To propose recommendations for harmonising monitoring procedures.
• To set up a system for regularly collecting occupational doses for these individuals and for dissemination of this information.
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WGIR conducted a world-wide survey
• to gain insight into the current practice of occupational radiation protection in industrial radiography
• respectively addressed to −Regulatory Bodies (Licensing bodies for radiation
protection)−Operating Companies (Licensees)− Industrial Radiographers / Radiography Technicians
(“Operators”)
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Subjects of questionnaires
1. qualifications and training of radiographers in radiation protection,
2. learning from incidents (accidents, near misses, deviations from normal operations),
3. systems and procedures in place for safe operation,
4. emergency preparedness and response, and
5. individual monitoring.
The IAEA Specific Safety Guide on Radiation Safety in Industrial Radiography (IAEA Safety Standards Series No. SSG-11) was used to develop questions
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Distribution of questionnaires
Operator Company Regulatory Body
English X X X
German X X
French X X
Portuguese X X
Spanish X X
Dutch X
Russian X X
Chinese X X
• Questionnaires were translated in various languages
• Operator and Company questionnaires were distributed via the networks of the WGIR members• NDT companies• (Inter)national NDT societies
• Regulatory Body questionnaire was distributed by IAEA
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Responses to the questionnaires
Operator Questionnaire
Company Questionnaire
Regulatory Body (RB)Questionnaire
Number of operators
Number of companies
Number of countries
Number of Companies
Number of Countries
Countries contacted
Countries responded
RBs contacted
RBs responded
Africa 17 7 3 7 4 35 8 35 8
Asia-Pacific
49 34 7 33 6 27 13 35 16
Europe 166 60 16 28 13 49 27 49 27
Latin America
72 17 3 19 4 20 5 20 5
North America
128 33 2 8 2 2 2 3 3
Global 432 151 31 95 29 133 55 142 59
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Results and discussion
• For each questionnaire the responses to each item were consolidated in an Excel workbook
• Responses were statistically analyzed • Various hypotheses on correlations between
items were tested • The following slides contain the main
findings from the three questionnaires.
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Qualifications and training of radiographers in radiation protection• Initial radiation protection training appears to
be well accepted and established • 98% of operators had received RP training
• Refresher training was less well established• 70% of RBs required refresher training• 80% (60%) of companies offered refresher (practical) RP training
• Emergency response training is also less established • 87% of operators had received emergency response training• only 65% of operators had been involved in practical exercises
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Learning from incidents
• Rate of occurrence of incidents in IR:
• Level of dissemination of lessons learned appears to be low• 40% of NDT companies do not share learning with other organizations
Operator responses Company responses
# per operator per 5 year
# per company per 5 year
# per operator per 5 year
# per company per 5 year
Accidents 0.04 4.0 0.03 1.1
Near Misses 0.1 6.2 0.05 1.8
Deviations 0.6 29.3 0.05 1.8
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Systems and procedures in place for safe operations• Systems and procedures should be in place
for protecting the operator and the public• Results of compliance inspection are
perhaps the best indication of whether such systems and procedures are in place
• Compliance inspections are performed by NDT companies and regulatory bodies
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Subjects of compliance inspections
Subject Company Regulatory Body
Proper wearing of passive individual dosimeters 95% 98%
Proper wearing and use of active individual dosimeters 93% 90%
Proper use of survey meters 95% 96%
Proper use of collimators 90% 88%
Proper warning system at the work site 93% 98%
Dose rate at the boundary of the work site within the limits set 92% 90%
Proper use of alarm systems 86% 96%
Proper training and qualifications of radiographers 91% 100%
Operator knowledge of procedures 88% 96%
Pre-operation specific equipment checks 82% 86%
Equipment condition 85% 98%
Emergency preparedness 74% 96%
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Most common shortcomings
Company compliance inspections RB compliance inspections
1. No proper use of collimators2. Dose rate at the boundary of the
work site above limits set3. No proper use of survey meters4. No pre-operation specific
equipment checks being performed
5. Poor operator knowledge of procedures
1. No proper use of survey meters2. No proper warning system to
prevent entry to the work site3. Poor emergency preparedness4. No proper use of alarm systems
5. Dose rate at the boundary for the work site not within limits set
• Results of the shortcomings perhaps reflect a different focus• Company perhaps focusing on company procedures• Regulatory body may have a focus on public protection
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Emergency preparedness and response
• Radiation sources used for industrial radiography purposes have high radiation outputs and are potentially very hazardous
• It is essential that systems are in place for emergency preparedness and response• in particular an emergency plan for incidents
with gamma radiography sources
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Implementation of emergency plans
• Almost all regulatory bodies (98%) stated that they require NDT companies to have an emergency plan;
• 95% of NDT companies stated that they had an emergency plan; and
• over 90% of radiographers stated that their NDT company had an emergency plan for site radiography
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Emergency response equipment
• Only three-quarters of regulatory bodies required NDT companies to have emergency equipment
• However 90% of NDT companies stated that they had emergency equipment for site radiography • primarily long tongs, shielding material, and an
emergency or rescue container.
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Individual monitoring
• All RBs required personal monitoring with passive dosimeters• 80% of RBs also required active dosimeters
• With at least audible alarms
• All Companies provided passive dosimeters• 94% provided active dosimeters
• Almost all with at least audible alarms• About two thirds also with visual alarms
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Dose distribution
• The radiographer data are for 234 radiographers, the NDT company data are for nearly 3500 radiographers, and the regulatory body data are for over 16,000 radiographers
• Average dose• Radiographer data: 3.4 mSv• RB data: 2.9 mSv
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Dose versus workload
• No correlation found• Radiation protection in industrial
radiography is not being effectively optimized
• Mean occupational dose per radiographic exposure• 4.8 ± 2.3 μSv for all operators• 2.9 ± 1.2 μSv for operators with
workload > 100 exposures• No effect on dose per exposure
found with:• level of NDT training• type of sources being used, • activity of sources, • use of collimation, or• incidence of events
• But limited data numbers
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Conclusions (1 of 3)
• Initial radiation protection training for radiographers is reasonably well established, but there is room for improvement especially with respect to refresher training and practical emergency response training
• The frequency of occurrence of incidents (accidents, near missed and deviations) is not trivial, and methods such as better incident reporting, analysis, feedback and sharing lessons learned need to be better utilized
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Conclusions (2 of 3)
• Collimators and diaphragms are not being used as often as they should be
• Survey meters are not as widely available as they should be• Individual monitoring, as reported, is well established, with
passive and, usually, active dosimeters. The establishment and use of investigation levels needs to be improve
• Warning systems to prevent entry to the work area during site radiography were not always as effective as desired. Better communication at the site is indicated
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Conclusions (3 of 3)
• Emergency plans were widely prevalent, but there seemed to be some issues regarding specific training for radiographers with respect to emergencies
• Occupational doses received by radiographers varied considerably, with no correlation with radiographic workload
There is considerable scope for improvement in radiation protection
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Thank you!