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Part 10

Part 10. IAEA Training Material on Radiation Protection in Nuclear Medicine. R adioactive Waste. Objective.

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Part 10

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  1. Part 10 IAEATraining Material on Radiation Protection in Nuclear Medicine RadioactiveWaste

  2. Objective To be aware of the general principles of the handling and the safety of radioactive waste. To be able to identify, store and dispose of the different types of waste generated in a nuclear medicine department Part 10. Radioactive waste

  3. Content • Introduction • Basic requirements & legal framework • Waste collection, segregation and storage • Waste treatment and disposal • Examples of waste management in nuclear medicine. Local rules. Part 10. Radioactive waste

  4. Module 10.1 Introduction IAEATraining Material on Radiation Protection in Nuclear Medicine Part 10Radioactive Waste

  5. Radioactive Waste inNuclear Medicine The use of unsealed sources in diagnosis and therapy will generate radioactive waste of different kinds during preparation, patient examination and care Part 10. Radioactive waste

  6. Radioactive Waste inNuclear Medicine Sealed sources used for calibration and quality control of equipment, Point sources and anatomical markers, will end up as radioactive waste. Part 10. Radioactive waste

  7. Radioactive Waste inNuclear Medicine • Solid waste. Cover papers, gloves, empty vials and syringes. Radionuclide generators. Items used by hospitalized patients after radionuclide therapy. Sealed sources used for calibration of instruments. Animal carcasses and other biological waste. • Liquid waste. Residues of radionuclides. Patient excreta. Liquid scintil- lation solutions. • Gaseous waste. Exhausted gas from patients in nuclear medicine Part 10. Radioactive waste

  8. Module 10.2 Basic requirements and legal framework IAEATraining Material on Radiation Protection in Nuclear Medicine Part 10Radioactive Waste

  9. FUNDAMENTAL PRINCIPLES • Radioactive waste shall be managed in such a way as to secure an acceptable level of protection for human health. • Radioactive waste shall be managed in such a way as to provide an acceptable level of protection of the environment. • Radioactive waste shall be managed within an appropriate national legal framework including clear allocation of responsibilities and provision for independent regulatory functions. • Generation of radioactive waste shall be kept to minimum practicable. Part 10. Radioactive waste

  10. WASTE MANAGEMENT DEFINITIONS Radioactive material for reuse/recycle Exempted waste Pre-treatment Treatment Interim storage Conditioning Transportation Disposal Part 10. Radioactive waste

  11. Waste management framework • Organization and responsibilities • Waste inventory • Waste management plan • Waste minimization • Safety assessments • Facilities • Transports • Staff training • Documentation and records • Quality assurance Part 10. Radioactive waste

  12. Quality assurance • Local rules • Normal working conditions • Accidents • Waste identification and traceability • Record system • Process control • Safe handling of radioactive sources • Facilities • Monitoring • Quality of containers • Arrangements for storage • Documentation • Audits Part 10. Radioactive waste

  13. Module 10.3 Waste collection, segregation and storage IAEATraining Material on Radiation Protection in Nuclear Medicine Part 10Radioactive Waste

  14. Radioactive waste-BSS • III.8.Registrants and licensees shall: • ensure that the activity and volume of any radioactive waste that result from the sources for which they are responsible be kept to the minimum practicable, and that the waste be managed, i.e. collected, handled, treated, conditioned, transported, stored and disposed of, in accordance with the requirements of the Standards, and any other applicable standard, and • segregate, and treat separately if appropriate, different types of radioactive waste where warranted by differences in factors such as radionuclide content, half-life, concentration, volume and physical and chemical properties, taking into account the available options for waste disposal. Part 10. Radioactive waste

  15. WASTE MINIMIZATION A good planning of the nuclear medicine activity including selection of radionuclides and good working procedures will result in a reduced volume of radioactive waste. Selection of radionuclides should take into account half-life, type of radiation, activity etc. Working procedures should take into account the number of operations and material involved in the preparation, the risk of contamination etc. Part 10. Radioactive waste

  16. Examples of waste from Nuclear Medicine • Biological waste which may undergo decomposition. • Infectious waste requiring sterilization prior to disposal. • Broken glass-ware, syringes etc, requiring collection in separate containers to prevent personnel being injured. • Radionuclide generators • Bed linen and clothing from hospital wards. • Liquid scintillation solutions • Patient excreta ? Part 10. Radioactive waste

  17. Segregation of waste from Nuclear Medicine • Some examples of the different types of waste generated in a hospital • Liquid waste containing short-lived radionuclides capable of being stored for decay (radiopharmaceuticals). • Solid waste containing short-lived radionuclides capable of being stored for decay (contaminated items). • Liquid waste which after proper treatment and conditioning can be handled in the public waste treatment system (long-lived radiopharmaceuticals). • Solid waste which after proper treatment and conditioning can be handled in the public waste treatment system (biological samples, anatomical markers). • Sealed sources. (sources for calibration and QC) Part 10. Radioactive waste

  18. Segregation/Waste containers • Containers to allow segregation of different types of radioactive waste should be available in areas where the waste is generated. The containers must be suitable for purpose (volume, shielding, leak proof, etc.) • Glassware with radionuclides (short half-life) • Syringes and needles • Gloves and paper • Glassware with radionuclides (medium half-life) • .. • .. Part 10. Radioactive waste

  19. Storage of radioactive waste A room for interim storage of radioactive waste should be available. The room should be locked, properly marked and ventilated. Each type of waste should be kept in separate containers properly labeled to supply information about the radionuclide, activity concentration etc. Flammable goods should be kept apart. Records should be kept where the origin of the waste can identified. Part 10. Radioactive waste

  20. Storage of radioactive waste Part 10. Radioactive waste

  21. Storage of radioactive waste Part 10. Radioactive waste

  22. Storage of radioactive waste Part 10. Radioactive waste

  23. Module 10.4 Waste treatment and disposal IAEATraining Material on Radiation Protection in Nuclear Medicine Part 10Radioactive Waste

  24. Radioactive waste-BSS • ”III.9. Registrants and licensees shall ensure that radioactive substances from authorized practices and sources not be discharged to the environment unless: • either clearance has been granted for the radioactive substance or the discharge is within the discharge limits authorized by the Regulatory Authority;” Part 10. Radioactive waste

  25. Treatment of solid waste(general principles) The objective of the treatment process is to reduce the volume of solid waste, reduce or eliminate potential hazards associated with the waste and to produce waste packages suitable for destruction, storage or transportation to and disposal at a licensed repository. Part 10. Radioactive waste

  26. Conditioning of solid waste Waste packages Public system National plant Solid waste should be conditioned in order to produce a waste form suitable for storage and transportation governed by the properties of the waste, the transport regulations and the specific waste disposal acceptance requirements Part 10. Radioactive waste

  27. DISPOSAL OF SOLID WASTE • Example of national regulations of disposal of waste from • hospitals: • Disposal via the public waste treatment system • Maximum 10 ALImin /month and maximum 1 ALImin • per package. • The dose rate at the surface of each package should be • <5 uGy/h. • The package should not contain any single sealed source • with activity >50 kBq. • Each package should be properly labeled with a warning • sign containing information on radionuclide and activity. The • origin of the waste should also be given on the package. Part 10. Radioactive waste

  28. LIQUID WASTEEffluent discharges Liquid waste Treatment Solid waste Effluents • Liquid waste can be transformed to solid waste by some • treatment process such as evaporation. • Liquid waste can be discharged to the environment if either clearance has been granted for the radioactive substance or the discharge is within the limits authorized by the Regulatory Authority. Part 10. Radioactive waste

  29. Effluent dischargesExample of rules <10 ALImin per month and <1 ALImin or not more than 100 MBq at each occasion. Flush with plenty of water. Use a special sink for the discharge. A label should be posted informing personnel that disposal of liquid waste is allowed at this point. Part 10. Radioactive waste

  30. National discharge limitsExample Part 10. Radioactive waste

  31. Module 10.5 Examples and Local Rules IAEATraining Material on Radiation Protection in Nuclear Medicine Part 10Radioactive Waste

  32. SHORT-LIVED RADIONUCLIDES Radionuclides such as Tc-99m, I-123, Tl-201, I-131 Sm-153, Sr-89 etc. should, after segregation, be stored for decay during a period of time established locally by the RPO, taking into account all applicable national regulations. Part 10. Radioactive waste

  33. PATIENT EXCRETA • Diagnostic patients • Generally no need for collection of excreta. • Ordinary toilets can be used. • Therapy patients • Different policies in different countries: • Use separate toilets equipped with delay tanks or • an active treatment system, or • Allow the excreta to be released directly into • the sewer system. • The Regulatory Authority should define the principles taking • the environmental impact into consideration Part 10. Radioactive waste

  34. LIQUID DISCHARGESI-131 Estimation of the generic clearance value for aquatic release of I-131 is quite complicated. Is all material retained in the sewage sludge at sewage treatment works or is all the activity discharged to a water body? Who will get the highest exposure? Which dilution of the radionuclide concentration will be found etc? Calculations must be made by qualified persons taking into account the guidance given by IAEA (TECDOC 1000) Part 10. Radioactive waste

  35. Tc-generators Store for decay Check for contamination Dismount the generator Return to producer Exempted waste? Part 10. Radioactive waste

  36. Tc-generator(store for decay & dismounting) Assume a generator with 20 GBq Mo-99 at reference time. The half-life of Mo-99 is 2.75 d and the exemption activity is 1 MBq (BSS). The time for interim storage should then be 40 d. The dose rate at 1 m from the unshielded column will then be 0.04 μSv/h. Hence, the external exposure will be very small when dismounting the generator. The dismounted column is exempted waste and the sign of its previous radioactivity should be removed. The column can now be discharged together with similar waste from the hospital. Part 10. Radioactive waste

  37. DISMOUNTING A TC-GENERATOR 3. Check for radiation 1. Check for radiation 2. Remove the plastic cover 4. Remove the column Part 10. Radioactive waste

  38. DISMOUNTING A TC-GENERATOR 5. Remove the lead shield 7. Check if the columncan be classified as exemtedwaste 6. Separate the different materials Part 10. Radioactive waste

  39. Sealed sources for QC of equipment • Co-57 flood sources, anatomical markers etc used in diagnostic nuclear medicine • Co-57, Cs-137 etc calibration sources for activity meters. Should be transferred to a national plant for final disposal Part 10. Radioactive waste

  40. Liquid scintillation solutions Small activities of H-3 or C-14 in organic solvents. Glass or plastic vials of 5-10 ml volume. Controlled Incineration in a plant! Part 10. Radioactive waste

  41. Biological waste Pre-treatment (deep freezing, quicklime, chemical methods) Incineration Store for decay Transfer to depository Exempted waste Part 10. Radioactive waste

  42. LOCAL RULES Department of Diagnostic Nuclear Medicine Radiation Protection Manual RADIOACTIVE WASTE Gloves, cover paper etc Syringes, needles Vials containing Tc99m Tl-201, In-111, Ga-67 Technetium generator Flood sources, markers Part 10. Radioactive waste

  43. Summary • The requirements of the BSS and other IAEA publication formulates the general rules regarding waste management. • An efficient national infrastructure and policy is required. • National regulations regarding disposal of waste should be available and form the basis of local rules in the hospital. • A well planned use of radionuclides is fundamental in a waste management system. • A system for segregation of the waste should be available in the department. This includes proper containers. • A room for storage of waste should be available. • A quality assurance programme in nuclear medicine should include management of radioactive waste. Part 10. Radioactive waste

  44. Questions? Part 10. Radioactive waste

  45. DISCUSSION How should a room for interim storage be classified? Controlled area? Supervised area? Where should the room be localized and how shouldit be designed? Part 10. Radioactive waste

  46. DISCUSSION A physicist is measuring the radionuclide purity of a technetium generator. The measurementsreveal small amounts of Pu-239. Will this affectthe disposal of the generator? Part 10. Radioactive waste

  47. DISCUSSION Discuss the possibilities of incineration of radioactivewaste. What basic requirements should be fulfilled bythe plant? Part 10. Radioactive waste

  48. Where to Get More Information • Other sessions • Part 4 Safety of sources. Design of facilities • Part 9. Quality assurance • Part 5 Occupational protection • Further readings • IAEA, International Basic Safety Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources Safety Series No.115, (1996) • IAEA, The Principles of Radioactive Waste Management, Safety Series No. 111-F, (1995) • IAEA, A Safety Guide on Predisposal management of radioactive waste from medicine, industry and research, Safety Standard Series No 111-G-2.2 (1997) • IAEA/WHO Manual on Radiation Protection in Hospitals and General Practice, Volume 4, Nuclear Medicine. Manuscript. • Handling and disposal of radioactive materials in hospitals, ICRP Publication No. 25. Oxford, Pergamon Press, 1977 (Annals of the ICRP No. 2) Part 10. Radioactive waste

  49. PRE-TREATMENT • Any or all the operations prior to waste treatment • such as: • collection • segregation • chemical adjustment • decontamination Collection and segregation of waste are important factors to consider in a system of waste management in nuclear medicine Part 10. Radioactive waste

  50. Exempted waste Storage for decay may release the waste from nuclear regulatory control. Clearance levels should be given by the national Regulatory Authority. All signs of its radioactive origin should be removed and the waste can be treated as any similar waste in the hospital taking into account the possible biological and chemical hazards. This is the most common way to handle radioactive waste in nuclear medicine. Part 10. Radioactive waste

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