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Actions After Finding an Orphan Radioactive Source

Actions After Finding an Orphan Radioactive Source. 2 - Transport. Introduction. By the end of this module students will be able to: Outline the actions to be taken once an orphan source is found including: Controlling access for radiological safety Identifying and characterizing the source

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Actions After Finding an Orphan Radioactive Source

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  1. Actions After Findingan Orphan Radioactive Source 2 - Transport

  2. Introduction • By the end of this module students will be able to: • Outline the actions to be taken once an orphan source is found including: • Controlling access for radiological safety • Identifying and characterizing the source • Packaging and transporting the source • Conditioning the source for storage or disposition • Storing the source safely and securely

  3. Overview • Initial actions • Orphan source identification and characterization • Packaging and transport • Conditioning • Safe and secure storage

  4. Next Actions • Once the initial actions have been completed, the device/source will usually need to be: • Packaged for transport • Transported to a safe and secure location • Perhaps conditioned • Stored in a safe and secure manner until a final decision regarding its disposition can be made

  5. Packaging and Transport • Sources should be packaged and transported in accordance with the applicable regulations • Most countries follow the IAEA transport regulations inSSR-6 (superseding TS-R-1) • Transport regulations are complex - get expert help if possible • If not, use the Schedules in SSG-33 (superseding TS-G-1.6)

  6. Schedules • Schedules for UN numbers are in SSG-33 • Summarize regulatory requirements applicable to specific types of shipments • To avoid repetition, common regulatory provisions are separated out • For most orphan source shipments: • UN2915 (Type A, non-special form), • UN2916 (Type B(U), non-fissile) and • UN2917 (Type B(M), non-fissile)

  7. Packaging and Transport • Public health and safety are the priority, so if they are at immediate risk and it is not possible to fully comply with the regulations, use good radiation safety practice to move the source to a safe and secure location • See Georgia RTG source recovery video for example

  8. Packaging and Transport • Rather than attempt to teach the IAEA transport regulations, this module will show how to find the right Schedule and use it, making some reasonable assumptions • Assumptions include: • No air transport • No fissile material • Significant quantities of radioactivity • Sealed sources, no dispersed radioactivity • Only this source(s) on vehicle

  9. Form • The radioactivity, radionuclide and form largely determine the transport requirements • The first two should be known by now • For a source to be regarded as “special form” requires a valid certificate • Most orphan sources are unlikely to have one, hence it is assumed that they will be “other than special form”

  10. A2 Value • For the radionuclide of the source look up the A2 value in Table 2 of SSR-6 • If the orphan source radioactivity is less than this value, it will be a Type A shipment with a UN identification number of 2915 and this schedule in SSG-33 will be used • If it is greater, it will be a Type B shipment and will use the schedule for either: • UN2916, or UN2917 depending on package

  11. Some A2 Values

  12. Packaging/Transport Overview • Select a proper packaging • Package the source as specified • Measure dose rates on the package • Label and mark the package accordingly • Ensure contamination is within limits • Load the package on vehicle and placard it • Ensure dose rates on vehicle are within limits • Complete transport documents

  13. Type A (Activity ≤ A2) • Proper shipping name: • UN2915 RADIOACTIVE MATERIAL • TYPE A PACKAGE • non-special form • non-fissile or fissile-excepted • Use schedule for UN2915 • Needs a Type A package • Type A packages have been designed for normal conditions of transport • Source packaged to package design specs

  14. Type A Packaging Examples

  15. Type B (Activity > A2) • Needs an available Type B package • Can be Type B(U) or Type B(M) • If Type B(U), proper shipping name: • UN2916 RADIOACTIVE MATERIAL, TYPE B(U) PACKAGE, non-fissile or fissile-excepted • Use schedule for UN2916 • If Type B(M), proper shipping name: • UN2917 RADIOACTIVE MATERIAL, TYPE B(M) PACKAGE, non-fissile or fissile-excepted

  16. Type B (Activity > A2) • Type B packages have been designed for accident conditions of transport • Source must be packaged according to specifications in thepackage approval certificate

  17. Examples of Type B Packages

  18. Labelling on Package • Measure dose rates on the surface and at 1 metre from the surface of the package • Transport index is a number = 1 metre value in mSv/h times 100 • Dose rates determine the label needed • Need two labels, on opposite sides • Labels need to be filled in with: • Radioisotope, activity and transport index

  19. Labels

  20. Marking on Package • Consignor or consignee, or both • Permissible gross mass if > 50kg • Proper shipping name • Type A, Type B(U) or Type B(M) as approp. • Other identification marks in accordance with applicable schedule (UN2915, UN 2916 or UN2917)

  21. Contamination Limits • Measure non-fixed contamination (removable) on the package by swipe and contamination detector probe • Ensure it is less than: • 4 Bq/cm2 for beta/gamma emitters and low toxicity alpha emitters (§508 SSR-6 former227 TS-R-1) • 0.4 Bq/cm2 for all other alpha emitters • Averaged over 300 cm2

  22. Loading and Placarding • Most found source shipments will be exclusive use shipments (with a single consignor and all loading/unloading carried out under the direction of the consignor) • Load and secure the package in or on the vehicle • Measure dose rates and ensure that they are within the limits • Placard the vehicle on the sides and rear

  23. Maximum Radiation Levels for Exclusive Use • 2 mSv/h on any surface of the package, or if enclosed and secured, 10 mSv/h • 2 mSv/h on any outer surface of the vehicle, or for an open vehicle: • 2 mSv/h on any point on the vertical planes projected from the outer edges of the vehicle • 0.1 mSv/h at any point 2 m from the vertical planes represented by the outer lateral surfaces of the vehicle (or outer edge planes for an open vehicle)

  24. Exclusive Use – Closed Vehicle

  25. Transport Documents - Consignment • Name and address of consignor and consignee • Proper shipping name, Class 7, UN Number • Name of radionuclide(s) • Physical and chemical form • Maximum activity (Bq) • Category of label (I-WHITE, II-YELLOW, or III-YELLOW) • Transport index • Any identification marks for package approval • EXCLUSIVE USE SHIPMENT • Consignor’s declaration, signed and dated

  26. Transport Documents - Carrier • Actions to be taken by the carrier • Supplementary requirements for loading, stowage, carriage, handling and unloading • Restrictions on mode of transport, routing • Emergency arrangements

  27. Example of Transport Document

  28. Loading Teletherapy Head for Transport

  29. Teletherapy Head Ready for Transport

  30. Transport Security Considerations • Sources are potentially vulnerable in transport, between the location where the source is found and storage • Security guidance incorporates the concept of defence in depth and uses a graded approach

  31. Transport Security Levels • Enhanced security for: • Category 1 & 2 sources in the Code of Conduct • Sources >3000 A2 • Basic security for all other found orphan sources • IAEA Nuclear Security Series No. 9 has the details

  32. Basic Security Considerations • General security provisions • Basic security awareness training • Personnel identity verification • Security verification of conveyances • Written instructions • Exchange of security related information • Trustworthiness determination

  33. Enhanced Security Considerations • Basic security level plus: • Identification of carriers and consignors • Security plans • Tracking devices • Communications from the conveyance • Additional provisions for road, rail and inland waterway

  34. Summary • Radiological safety is the first priority on finding an orphan source • Then comes identification and characterization of the source • Followed by packaging and transporting it to a better location safely and securely • Sometimes the source might need conditioning • Finally, it needs to be stored safely and securely

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