Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Categorization of Radioactive Sources

Slide 2 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 To understand categorization system of radioactive sources and its application in establishing the appropriate degree of regulatory control for activities relating to the safety and security of radioactive sources. Objective

Slide 3 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Objective and Scope Categorization system Implementation of the categorization system Appendix I - II and Annex I - II Contents

Slide 4 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Part I: Objectives and scope of categorization

Slide 5 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Provides a system for ranking of sources and practices in terms of their potential to cause harm to human health. Categorization supports international harmonization of controlling radioactive sources and their security  Code of Conduct on the Safety and Security of Radioactive Sources  Guidance on the Import and Export of Radioactive Sources Objectives of categorization of radioactive sources

Slide 6 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Developing or refining national regulatory infrastructures Developing national strategies for improving control over radioactive sources Optimizing use resources by setting priorities for regulation Optimizing security measures for radioactive sources Emergency planning and response Applications of categorisation

Slide 7 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Radioactive sealed sources Sources used in industry, medicine, agriculture, research and education Sources within military or defence programmes, where appropriate in the national context Categorization is concerned with sealed sources, however, the method can also be used to unsealed sources. Scope of the RS-G-1.9

Slide 8 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Radiation generating devices (x-ray machines, accelerators) Nuclear material Waste management of disused radioactive sources Packages of radioactive material in transport RS-G-1.9 is NOT applicable to

Slide 9 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 A national categorization for establishing the appropriate degree of regulatory control should  be based on a national inventory of practices and sources  consider national circumstances and resources  Take into account also practices and sources not covered by the RS-G-1.9: s Use of unsealed sources s Use of x-ray devices and accelerators Application of the Categorisation Guidance

Slide 10 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Part II: Categorization system

Slide 11 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 The categorization is based on the concept of dangerous sources which are quantified in terms of D values. The D value is the radionuclide specific activity of a source which, if not under control, could cause severe deterministic effects. D values are used as normalizing factors to provide a reference for comparing risks. Categorization System

Slide 12 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 An unshielded source (the D 1 value)  carried in the hand for one hour  carried in a pocket for 10 hours  being in a room for days to weeks Dispersal of a source by fire, explosion or human action (the D 2 value)  inhalation, ingestion and/or skin contamination The lower value of D 1 and D 2 is used as the D value. Exposure scenarios used in deriving the D values

Slide 13 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Dose criteria used in deriving the D values TissueDose criteria Bone marrow1 Gy in 2 days Lung6 Gy in 2 days from low LET 25 Gy in a year from high LET Thyroid5 Gy in 2 days Skin/tissue (contact)25 Gy at a depth of 2 cm (or 1 cm for the hand), for a period of 10 h Bone marrow1 Gy in 100 h for a source that is too big to be carried

Slide 14 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Radionuclide D (TBq) Am Co Cs Ir Pu Sr Tc-99 m 0.7 Examples of the D values

Slide 15 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Initial ranking of sources: The activity (A) of a source is divided by the corresponding radionuclide specific D value. For commonly used sources the ratio A/D ranges from 10 6 to To obtain useful number of categories also other factors are considered: physical and chemical form type of shielding circumstances of use accident case histories Categorization System

Slide 16 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Five categories are introduced Categorization System (cont) Category Activity ratio (A/D) 1 A/D ≥ > A/D ≥ >A/D ≥ >A/D ≥ >A/D and A > exempt

Slide 17 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Examples Radioisotope thermoelectric generators (RTGs) Irradiators Teletherapy sources Fixed, multi-beam teletherapy (gamma-knife) sources Category 1 Sources A/D ≥ 1000

Slide 18 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Examples Industrial gamma radiography sources High/medium dose rate brachytherapy sources Category 2 Sources 1000 > A/D ≥ 10

Slide 19 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Examples Fixed industrial gauges that incorporate high activity sources Well logging gauges Category 3 Sources 10 > A/D ≥ 1

Slide 20 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Examples Low dose rate brachytherapy sources (except eye plagues and permanent implants) Industrial gauges that do not incorporate high activity sources Bone densitometers Static eliminators Category 4 Sources 1 > A/D ≥ 0.01

Slide 21 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Examples Low dose rate brachytherapy eye plagues and permanent implant sources X-ray fluorescence (XRF) devices Electron capture devices Mossbauer spectrometry sources Positron emission tomography (PET) sources Category 5 Sources 0.01 >A/D and A > exempt

Slide 22 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Summary of Categorization System exempt Teletherapy sources Irradiators Industrial gamma radiography sources High/medium dose rate brachytherapy sources Industrial gauges with high activity sources Well logging gauges Low dose rate brachytherapy sources Industrial gauges with moderate/low activity sources X-ray fluorescence (XRF) devices Electron capture devices Activity ratio A/D

Slide 23 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Part III: Implementation of the categorization system

Slide 24 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Regulatory measures A factor to be taken into account in a graded system for notification, registration and inspections. Assist in ensuring that allocation of resources to protection measures is commensurate with the degree of risk. Use of the Categorization System Security measures To optimize security measures for radioactive sources, including measures directed against their possible malicious misuse.

Slide 25 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 National register of sources To optimize decisions regarding which sources should be included and what level of detail should be used in a national register of sources. Use of the Categorization System (cont) Import/export controls To optimize decisions regarding which sources should be subject to import and export controls, in meeting national and international standards.

Slide 26 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Labelling of high activity sources To guide decisions regarding which sources should be marked with an appropriate label warning of the radiation hazard. Use of the Categorization System (cont) Emergency preparedness and response To ensure that emergency preparedness plans and response to accidents are commensurate with the hazards posed by the source.

Slide 27 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Prioritization for regaining control over orphan sources To inform decisions relating to how efforts should be focused to regain control over orphan sources. Use of the Categorization System (cont) Communication with the public To provide a basis for explaining the relative hazard associated with events involving radioactive sources.

Slide 28 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 The regulatory body should use the D and A/D values of the Safety Guide RS-G-1.9 to categorize the sources included in the national inventory of sources Situations where case by case considerations needed: short half-life radionuclides unsealed sources aggregation of sources Use of categorization

Slide 29 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 In situations where several sources are in close proximity to each other, the regulatory body may wish to aggregate the activity in the sources to determine a situation based categorization for the purpose of regulatory control. In addition to activity, also other factors may need to be considered because aggregations in different situations may have different safety implications. Aggregation of sources

Slide 30 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Aggregation of sources where A i,n = activity of each individual source i of radionuclide n D n = D value of radionuclide n

Slide 31 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 The regulatory body should maintain a national register of radioactive sources The register should contain, as a minimum, Category 1 and 2 sources, but preferably also Category 3 sources The regulatory authority should determine whether also Category 4 and 5 should be included National register of radioactive sources

Slide 32 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 The Code of Conduct provides general guidance for the import and export of Category 1 and 2 sources (see Module 3-6) Import/Export guidance* provides specific procedures for the import and export authorization of Category 1 and 2 sources (see Module 3-6) Import and export of radioactive sources * Guidance on the Import and Export of Radioactive Sources IAEA, Vienna (2005)

Slide 33 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 The Safety Guide RS-G-1.9 provides also plain language descriptions of the categories for the purpose of public information. In summary: Communication with the public CategoryRisk in being close to an source 1Extremely dangerous 2Very dangerous 3Dangerous 4Unlikely to be dangerous 5Most unlikely to be dangerous

Slide 34 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 Categorization of Radioactive Sources, Safety Guide RS- G-1.9, IAEA, Vienna (2005) Code of Conduct on the Safety and Security of Radioactive Sources, IAEA, Vienna (2004) Guidance on the Import and Export of Radioactive Sources IAEA, Vienna (2005) Method for Developing Arrangements for Response to a Nuclear or Radiological Emergency: Updating IAEA- TECDOC-953, EPR-Method 2003, IAEA, Vienna (2003) References

Slide 35 Organization and Implementation of a National Regulatory Program for the Control of Radiation Sources Module 3-3 A moisture/density gauge includes a 300 MBq Cs-137 source and a 1.48 GBq Am-Be source. What is the appropriate category for such a device? Exercise