10. Radioactive waste (912 KB)

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10. Radioactive waste (912 KB)

  1. 1. Part 10Part 10 IAEA Training Material on Radiation Protection in Nuclear Medicine RRadioactiveadioactive WasteWaste
  2. 2. Part 10. Radioactive waste2Nuclear Medicine ObjectiveObjective 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
  3. 3. Part 10. Radioactive waste3Nuclear Medicine ContentContent Introduction Basic requirements & legal framework Waste collection, segregation and storage Waste treatment and disposal Examples of waste management in nuclear medicine. Loca .
  4. 4. Module 10.1 IntroductionModule 10.1 Introduction IAEA Training Material on Radiation Protection in Nuclear Medicine Part 10Part 10 RRadioactiveadioactive WWasteaste
  5. 5. Part 10. Radioactive waste5Nuclear Medicine The use of unsealed sourcesThe use of unsealed sources inin diagnosis and therapy willdiagnosis and therapy will generate radioactive waste of different kinds during preparation,generate radioactive waste of different kinds during preparation, patient examination and carepatient examination and care Radioactive Waste inRadioactive Waste in NuclearNuclear MedicineMedicine
  6. 6. Part 10. Radioactive waste6Nuclear Medicine Sealed sources used for calibration and quality control of equipment, Point sources and anatomical markers, will end up as radioactive waste. Radioactive Waste inRadioactive Waste in NuclearNuclear MedicineMedicine
  7. 7. Part 10. Radioactive waste7Nuclear Medicine Solid waste.Solid waste. Cover papers, gloves, empty vials and syringes.Cover papers, gloves, empty vials and syringes. Radionuclide generators. Items used by hospitalized patientsRadionuclide generators. Items used by hospitalized patients after radionuclide therapy. Sealed sources used for calibrationafter radionuclide therapy. Sealed sources used for calibration of instruments. Animal carcasses and other biological waste.of instruments. Animal carcasses and other biological waste. Liquid wasteLiquid waste.. Residues of radionuclides. Patient excreta. Liquid scintil-Residues of radionuclides. Patient excreta. Liquid scintil- lation solutions.lation solutions. Gaseous wasteGaseous waste.. Exhausted gas from patients in nuclear medicineExhausted gas from patients in nuclear medicine Radioactive Waste inRadioactive Waste in NuclearNuclear MedicineMedicine
  8. 8. Module 10.2Module 10.2 Basic requirements and legal framework IAEA Training Material on Radiation Protection in Nuclear Medicine Part 10Part 10 RRadioactiveadioactive WWasteaste
  9. 9. Part 10. Radioactive waste9Nuclear Medicine FUNDAMENTAL PRINCIPLESFUNDAMENTAL PRINCIPLES 1. Radioactive waste shall be managed in such a way as to secure an acceptable level of protection for human health. 2. Radioactive waste shall be managed in such a way as to provide an acceptable level of protection of the environment. 3. Radioactive waste shall be managed within an appropriate national legal framework including clear allocation of responsibilities and provision for independent regulatory functions. 4. Generation of radioactive waste shall be kept to minimum practicable.
  10. 10. Part 10. Radioactive waste10Nuclear Medicine Pre-treatment Treatment Conditioning Disposal Interim storage Transportation WASTE MANAGEMENTWASTE MANAGEMENT DEFINITIONSDEFINITIONS Radioactive material for reuse/recycle Exempted waste
  11. 11. Part 10. Radioactive waste11Nuclear Medicine •Organization and responsibilities •Waste inventory •Waste management plan •Waste minimization •Safety assessments •Facilities •Transports •Staff training •Documentation and records •Quality assurance Waste management frameworkWaste management framework
  12. 12. Part 10. Radioactive waste12Nuclear Medicine Quality assuranceQuality 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
  13. 13. Module 10.3Module 10.3 Waste collection, segregation and storage IAEA Training Material on Radiation Protection in Nuclear Medicine Part 10Part 10 RRadioactiveadioactive WWasteaste
  14. 14. Part 10. Radioactive waste14Nuclear Medicine 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. Radioactive waste-BSSRadioactive waste-BSS
  15. 15. Part 10. Radioactive waste15Nuclear Medicine WASTE MINIMIZATIONWASTE 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.
  16. 16. Part 10. Radioactive waste16Nuclear Medicine Examples ofExamples of waste fromwaste from Nuclear MedicineNuclear 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 ?
  17. 17. Part 10. Radioactive waste17Nuclear Medicine SegregationSegregation of waste fromof waste from Nuclear MedicineNuclear 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)
  18. 18. Part 10. Radioactive waste18Nuclear Medicine Segregation/Waste containersSegregation/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) •.. •..
  19. 19. Part 10. Radioactive waste19Nuclear Medicine 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. Storage of radioactive wasteStorage of radioactive waste
  20. 20. Part 10. Radioactive waste20Nuclear Medicine Storage of radioactive wasteStorage of radioactive waste
  21. 21. Part 10. Radioactive waste21Nuclear Medicine Storage of radioactive wasteStorage of radioactive waste
  22. 22. Part 10. Radioactive waste22Nuclear Medicine Storage of radioactive wasteStorage of radioactive waste
  23. 23. Module 10.4Module 10.4 Waste treatment and disposal IAEA Training Material on Radiation Protection in Nuclear Medicine Part 10Part 10 RRadioactiveadioactive WWasteaste
  24. 24. Part 10. Radioactive waste24Nuclear Medicine ”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;” Radioactive waste-BSSRadioactive waste-BSS
  25. 25. Part 10. Radioactive waste25Nuclear Medicine 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. Treatment of solid waste (general principles)
  26. 26. Part 10. Radioactive waste26Nuclear Medicine 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 National plantPublic system Waste packages Conditioning of solid wasteConditioning of solid waste
  27. 27. Part 10. Radioactive waste27Nuclear Medicine 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. DISPOSAL OF SOLID WASTEDISPOSAL OF SOLID WASTE
  28. 28. Part 10. Radioactive waste28Nuclear Medicine LIQUID WASTELIQUID WASTE Effluent dischargesEffluent discharges •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. Liquid waste EffluentsSolid waste Treatment
  29. 29. Part 10. Radioactive waste29Nuclear Medicine <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. Effluent dischargesEffluent discharges Example of rulesExample of rules
  30. 30. Part 10. Radioactive waste30Nuclear Medicine NationalNational discharge limitsdischarge limits ExampleExample Radionuclide Discharge (MBq each time) Discharge (MBq/month) Se-75 20 200 Sr-89 5 50 Tc-99m 100 30000 In-111 100 2000 I-125 1 10 I-131 1 10 Tl-201 100 6000
  31. 31. Module 10.5Module 10.5 Examples and Local Rules IAEA Training Material on Radiation Protection in Nuclear Medicine Part 10Part 10 RRadioactiveadioactive WWasteaste
  32. 32. Part 10. Radioactive waste32Nuclear Medicine 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. SHORT-LIVED RADIONUCLIDESSHORT-LIVED RADIONUCLIDES
  33. 33. Part 10. Radioactive waste33Nuclear Medicine 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 PATIENT EXCRETAPATIENT EXCRETA
  34. 34. Part 10. Radioactive waste34Nuclear Medicine LIQUID DISCHARGESLIQUID DISCHARGES I-131I-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)
  35. 35. Part 10. Radioactive waste35Nuclear Medicine Store for decay Dismount the generator Check for contamination Return to producer Tc-generatorsTc-generators Exempted waste?
  36. 36. Part 10. Radioactive waste36Nuclear Medicine Tc-generatorTc-generator (store for decay & dismounting)(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.
  37. 37. Part 10. Radioactive waste37Nuclear Medicine DISMOUNTING A TC-GENERATORDISMOUNTING A TC-GENERATOR 1. Check for radiation 2. Remove the plastic cover 3. Check for radiation 4. Remove the column
  38. 38. Part 10. Radioactive waste38Nuclear Medicine DISMOUNTING A TC-GENERATORDISMOUNTING A TC-GENERATOR 5. Remove the lead shield 6. Separate the different materials 7. Check if the column can be classified as exemted waste
  39. 39. Part 10. Radioactive waste39Nuclear Medicine Sealed sources for QC ofSealed sources for QC of equipmentequipment •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
  40. 40. Part 10. Radioactive waste40Nuclear Medicine Liquid scintillation solutionsLiquid 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!
  41. 41. Part 10. Radioactive waste41Nuclear Medicine Biological wasteBiological waste Pre-treatment (deep freezing, quicklime, chemical methods) Incineration Store for decay Transfer to depository Exempted waste
  42. 42. Part 10. Radioactive waste42Nuclear Medicine LOCAL RULESLOCAL RULES Department of Diagnostic Nuclear Medicine Radiation Protection ManualRadiation Protection Manual RADIOACTIVE WASTE Gloves, cover paper etc Syringes, needles Vials containing Tc99m Tl-201, In-111, Ga-67 Technetium generator Flood sources, markers
  43. 43. Part 10. Radioactive waste43Nuclear Medicine SummarySummary 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.
  44. 44. Part 10. Radioactive waste44Nuclear Medicine Quest i ons?
  45. 45. Part 10. Radioactive waste45Nuclear Medicine DISCUSSIONDISCUSSION How should a room for interim storage be classified? Controlled area? Supervised area? Where should the room be localized and how should it be designed?
  46. 46. Part 10. Radioactive waste46Nuclear Medicine DISCUSSIONDISCUSSION A physicist is measuring the radionuclide purity of a technetium generator. The measurements reveal small amounts of Pu-239. Will this affect the disposal of the generator?
  47. 47. Part 10. Radioactive waste47Nuclear Medicine DISCUSSIONDISCUSSION Discuss the possibilities of incineration of radioactive waste. What basic requirements should be fulfilled by the plant?
  48. 48. Part 10. Radioactive waste48Nuclear Medicine Where to Get MoreWhere to Get More InformationInformation Other sessionsOther sessions Part 4 Safety of sources. Design of facilities Part 9. Quality assurance Part 5 Occupational protection Further readingsFurther 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)
  49. 49. Part 10. Radioactive waste49Nuclear Medicine Any or all the operations prior to waste treatment such as: •collection •segregation •chemical adjustment •decontamination PRE-TREATMENT Collection and segregation of waste are important factors to consider in a system of waste management in nuclear medicine
  50. 50. Part 10. Radioactive waste50Nuclear Medicine Exempted wasteExempted 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.
  51. 51. Part 10. Radioactive waste51Nuclear Medicine The emplacement of waste in an approved specified facility (for example, near surface or geological repository) without the intention of retrieval ("confine and contain”). Disposal may also include the approved direct discharge of effluents (for example, liquid and gaseous wastes) into the environment with subsequent dispersion ("dilute and disperse”). Both methods are used in disposal of waste in nuclear medicine DISPOSAL
  52. 52. Part 10. Radioactive waste52Nuclear Medicine Operations intended to benefit safety and/or economy by changing the characteristics of the waste. Three basic treatment objectives are: •volume reduction •removal of radionuclides from the waste •change of composition. After treatment, the waste may or may not be immobilized to achieve an appropriate waste form. Generally not used ín Nuclear Medicine TREATMENT
  53. 53. Part 10. Radioactive waste53Nuclear Medicine Those operations that produce a waste package suitable for handling, transportation, storage and/or disposal. Conditioning may include the conversion of the waste to a solid waste form, enclosure of the waste in containers and, if necessary, providing an overpack. Should be applied to long lived sealed sources used for calibration and QC of nuclear medicine equipment. CONDITIONING
  54. 54. Part 10. Radioactive waste54Nuclear Medicine Storage of waste at different stages of the waste management process, before the final disposal. A room for interim storage of waste should be available in a nuclear medicine facility. It is mainly used for storage for decay to exemption levels. This is the main method of final disposal of waste generated in nuclear medicine. INTERIM STORAGE
  55. 55. Part 10. Radioactive waste55Nuclear Medicine Transportation of waste at different stages of the waste management process, before the final disposal. The international regulations established by IAEA shall be followed. Note that radioactive waste should be handled similar to any radioactive source. TRANSPORTATION
  56. 56. Part 10. Radioactive waste56Nuclear Medicine Department of Diagnostic Nuclear Medicine Radiation Protection Manual RADIOACTIVE WASTE Gloves, cover paper etc • Shall continuously be collected in the plastic bags placed in the rooms for preparation and injection of radiopharmaceuticals • When the bag is filled, seal it and move it to room 2:13. • Write the expected date of disposal (today's date+14 days) • Before disposal, check the external dose rate on the surface. If the dose rate does not exceed the background,.the bag can be disposed of as ordinary waste. • If the dose rate exceeds the background, write the new date of disposal on the bag and store it for another 14 days. LOCAL RULES 1LOCAL RULES 1
  57. 57. Part 10. Radioactive waste57Nuclear Medicine Department of Diagnostic Nuclear Medicine Radiation Protection Manual RADIOACTIVE WASTE Used syringes and needles etc • Shall continuously be collected in the shielded container in the rooms for preparation and injection of radiopharmaceuticals • When the container is filled, seal it and move it to the fume hood in room 2:13. • Write he expected date of disposal (today's date+4 weeks) on the container and place it behind the lead shield. • Before disposal, check the external dose rate on the surface. If the dose rate does not exceed the background,.the container can be disposed of according to the ordinary rules for dangerous items • If the dose rate exceeds the background, write the new date of disposal on the container and store it for another 4 weeks, LOCAL RULES 2LOCAL RULES 2
  58. 58. Part 10. Radioactive waste58Nuclear Medicine Department of Diagnostic Nuclear Medicine Radiation Protection Manual RADIOACTIVE WASTE Vials containing residues of Tc-99m • Shall continuously be collected in the shielded container in the room for preparation of radiopharmaceuticals • When the container is filled, seal it and move it to the fume hood in room 2:13. • Write the expected day of disposal (today's date+4 weeks) on the container and place it behind the lead shield. • Before disposal, check the external dose rate on the surface. If the dose rate does not exceed the background,.the container can be disposed of according to the ordinary rules for glassware • If the dose rate exceeds the background, write the new date of disposal on the container and store it for another 4 weeks, LOCAL RULES 3LOCAL RULES 3
  59. 59. Part 10. Radioactive waste59Nuclear Medicine Department of Diagnostic Nuclear Medicine Radiation Protection Manual RADIOACTIVE WASTE Vials containing residues of Tl-201, In-111 and Ga-67 • Measure the residual activity • Put the vial in the original lead shield and move it to room 2:13 • If the activity is below 100 MBq, open the vial and pour the content in the sewage system. Use the sink in room 2:13. Flush with plenty of water. Rinse the vial and dispose it as ordinary glass ware. Use protective gloves and clothing during the work. • Check for contamination of the sink. Clean it if contamination is detected • If the residual activity is >100 MBq, calculate the time of storage using the tables posted in the room. Write the date of disposal on the vial and put in the fume hood. LOCAL RULES 4LOCAL RULES 4
  60. 60. Part 10. Radioactive waste60Nuclear Medicine Department of Diagnostic Nuclear Medicine Radiation Protection Manual RADIOACTIVE WASTE Technetium generator • Put the used generator back into the transport container • Move the container to the room for interim storage of waste (no 01:24 located in the basement). The key to the room is kept by the Chief Technician • Fill in the record (generator no and today's date) • The used generators will be picked up every 8th week by the producer. Check the containers for contamination before they are removed. Fill in the date of removal in the record. • Notify the RPO (NN phone xxxxxx if contamination is detected) LOCAL RULES 5LOCAL RULES 5
  61. 61. Part 10. Radioactive waste61Nuclear Medicine Department of Diagnostic Nuclear Medicine Radiation Protection Manual RADIOACTIVE WASTE Sealed sources Flood sources, anatomical markers, check sources • Move the used source to the room for interim storage of waste (no 01:24 located in the basement). The key to the room is kept by the Chief Technician • Fill in the record (source id no and today's date) • The final disposal of the source is handled by the RPO (NN, phone xxxxxx) LOCAL RULES 6LOCAL RULES 6

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