Radiation Protection in Radiotherapy Part 15 Security of sources, and disposal of disused sources IAEA Training Material on Radiation Protection in Radiotherapy

Radiation Protection inRadiotherapyPart 15Security of sources, and disposal of disused sourcesIAEA Training Material on Radiation Protection in Radiotherapy

Part 15: Security and disposal of sources

Radiation Protection in Radiotherapy

BSS glossary:A source is:Anything that may cause radiation exposure, such as by emitting ionizing radiation or releasing radioactive substances or materials. For example, materials emitting radon are sources in the environment, a sterilization gamma irradiation unit is a source for the practice of radiation preservation of food, an X ray unit may be a source for the practice of radiodiagnosis, and a nuclear power plant is a source for the practice of generating electricity by nuclear power. A complex or multiple installation situated at one location or site may, as appropriate, be considered a single source for the purposes of application of the Standards.



ObjectivesBe able to apply the concept of a radiation source to radiotherapyUnderstand how sources in radiotherapy can be made secureBe familiar with appropriate ways to dispose of sources in radiotherapy



Contents1. Sources in radiotherapy2. Security of sources3. Disposal of disused sources



1. Sources in radiotherapyX Ray equipmentRadioactive sources for external beam radiotherapyRadioactive sources for brachytherapyOther sources



A note on exempted sourcesIn general radioactive sources used in radiotherapy will NOT qualify for exemption according to BSS schedule I



X Ray equipmentVery common source of radiation in radiotherapyNot of major concern for security of sources and disposal because no radiation is produced when the unit is turned off...Courtesy of Siemens Medical



Radioactive sources for external beam radiotherapyIn practice 137-Cs and more importantly 60-Co units need to be consideredMDS Nordion



Radioactive sources for EBTHigh activity (>100TBq (3000 Ci))Small (height and diameter a few centimeters)Relatively long half life of 5.26 years for 60-Co and 30 years for 137-CsHas been source of a major radiation accident in the past (Goinia)



A teletherapy 60-Co source5cm120TBq



Radiation accident in GoiniaEnd 1985 in BrazilPrivate radiotherapy unit moved location leaving a 137-Cs unit in former premisesAuthorities were not notifiedCs unit was scavenged as scrap metal



Goinia accidentSource assembly sold to scrap yardGlow in the dark caused attractionParts of the source distributed widely...



Goiania accidentSeveral persons showed gastrointestinal symptoms due to irradiationOne affected person contacted public health departmentA local physicist was involved in determining the extent of the accident and initiated evacuation of affected areas



Large scale accident Human Costs249 people contaminatedFour people died within 4 weeks



Environmental and financial costsLots of workLots of costsLots of waste



Radioactive sources for brachytherapyMany different isotopes and forms as discussed in part 6 of the courseBrachytherapy isotopes are in radiotherapy practice the most likely cause of concern for security and disposal of sources



Other sources



Other sourcesCheck sources for dosimetric equipmentCheck sources for shieldingExcept for sources for unsealed source radiotherapy (dealt with in the course on nuclear medicine) all sources can be considered sealedIn practice a small part of the radioactive inventoryof a radiotherapy department - the considerationsin regards to security and disposal for these sourcesare similar to brachytherapy sources



2. Security of sourcesBSS 2.34: Sources shall be kept secure so as to prevent theft or damage and to prevent any unauthorized legal person from carrying out any of the actions specified in the General Obligations for practices of the Standards (see paras 2.7-2.9), by ensuring that: (a)control of a source not be relinquished without compliance with all relevant requirements specified in the registration or licence and without immediate communication to the Regulatory Authority, and when applicable to the relevant Sponsoring Organization, of information regarding any decontrolled, lost, stolen or missing source; ...



...and...(b)a source not be transferred unless the receiver possesses a valid authorization; and (c) a periodic inventory of movable sources be conducted at appropriate intervals to confirm that they are in their assigned locations and are secure.



Security of sourcesNot a problem for X Ray equipment if one assumes thatthey are properly designed and maintained (compare part 10 of the course)only authorized persons are able to operate the equipmentunit cannot be accessed by un-authorized persons



Linac ConsoleKey required for operation



Security of sourcesAll radiation equipment must be locked when not in use...



Security of 60-Co sourcesIn teletherapy units:Mainly a feature of equipment designTreatment rooms must be lockedSource transfer only be done by qualified personsGreat care must be taken when disposing the source - it MUST be returned to an authorized person or company!!!



Must know the source housing and exposure mechanism designSourceHg pumpedin and outExposure mechanism



Security of brachytherapy sourcesSome info in part 6 on sourcesMay affect all aspects of source utilization:receipt of sourcesstoragehandlinguse on patientsdisposal125-I seeds - Courtesy Mentor



Safety AssessmentIdentification of the mechanisms for exposure (both routine and accidents)Realistic estimate of doses and likelihood of occurringIdentification of possible safety system failuresIdentification of protection measures needed



Source StorageSource stores must:provide protection against environmental conditionsbe only for radioactive materialsprovide sufficient shieldingbe resistant to firebe secure



Features of source storageSecure (lock and key)LabelsDifferent compartmentsShieldingEasy accessWell organized



Important to keep a good log bookUpdate with every source movementClear labelsIdentify all sourcesA drawing of the safe outline may be useful



Source transportAlways accompanied by qualified personDetails in part 14 of the course



Accountability of sourcesReceipt, storage, use and all movements of a source must be recorded



Accountability of Sources Source accountancy records should contain:radionuclide and activity of sourceslocation and description of sourcesdisposal details The records should be updated regularly, and the location of the sources checked.



Testing and MaintenanceTesting of safety systemsCalibration and testing of radiation monitorsLeak tests of sealed sourcesPeriodic examination of safety critical components



Testing and MaintenanceDocumentation must exist for all procedures:How to be doneWho is responsibleHow often to be done

Records of results must be kept



A lost source...A major concern for radiation protectionPossible in case of:Discharge of patients with temporary implants not completely removedIn theatre during implant of radioactive seeds Seeds are small



A lost sourceIn theatre a physicist should be present to identify a lost source immediatelyCan be located often best using a radiation detector



A lost source in the wardNotify physicist or radiation safety officer immediatelyHave a plan for the search...



A lost source? Need an emergency planMain actions



3. Disposal of disused sourcesA potential for accidentsDisposal routes should already be considered when ordering sourcesAccounting for sources includes their disposalResponsibility for sources only ends after they have been safely disposed and disposal has been documented



BSS Appendix III: PUBLIC EXPOSURE - Radioactive Waste III.8. Registrants and licensees shall: (a) ensure that the activity and volume of any radioactive waste that results 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 (b) 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.



Radiotherapy X Ray equipmentIn practice usually not a problemas no parts of the equipment are activatedif the unit is properly decommissionedthe unit is disposed off either in a condition which renders it unusable or sold to an appropriately licensed person - this also includes donationsthe regulatory authority is informed



Disposal of teletherapy sourcesDue to their high activity (even when not anymore fit for use on patients) the disposal of these sources poses a potential risk for severe accidentsIn practice this should not a be major problem if the source is replaced - in this case the manufacturer of the source shall also accept the source to be disposed



Potentially a problem if the teletherapy unit is decommissionedThe source should be disposed to an operator licensed to do sothis could be expensive but is cheaper than an accident

Appropriate transport containers must be used



Please noteA hospital is NOT a suitable place for long term storage of high activity sourcesThe source housing is usually NEITHER suitable for transport NOR for long term storage of the source



Brachytherapy source disposalPermanent implants walk out with the patientremaining sources must be disposed of appropriatelyFor temporary implant sources the disposal depends on activity and half life:short/medium half life, low/medium activity (e.g. 192-Ir LDR sources) can be stored until decayed to an activity which is below limit values specified by the regulatory authoritythis strategy does not work for high activity 192-Ir HDR sources or 137-Cs



192-Ir HDR sourcesTypically exchangedNeed trained personal for exchangeStorage not recommended



137-Cs sourcesDespite half life of 30 years most manufacturers only specify a useful life of 10years. This is mainly due to:risk of damage to the encapsulatione.g. Cs pellets in Microselectron bump into each other during loading of the applicatorsWipe tests requiredDisposal only to person authorized to accept sources



A note on the role of suppliersBSS appendix IV.9. In addition, and where applicable, registrants and licensees shall make suitable arrangements with suppliers of sources: (a) to establish and maintain mechanisms for suppliers to obtain information from the registrants and licensees or other users on the use, maintenance, operating experience, dismantling and disposal of sources, and in any particular normal or abnormal operating conditions that may be important for the protection of individuals or the safety of the source; Safety and security of sources is everyone's responsibility



SummarySafety and security must be considered for all sources in radiotherapySecurity of sources relies on a system of accounting for sourcesDisposal of sources is a major responsibility of the licensee - sources must only be disposed to an authorized person or company



Where to Get More InformationParts 6, 10 and 11 of the course


Any questions?


Question:Please discuss what records should be included in a system for accountability of sources used for external beam radiotherapy



The records should include:Name of authorized personLicensee and license conditionsWho ordered the source and whenSupplier (including address, license details and contact details)Source specifications (chemical form, Date delivered, received bySource certificateInstalled byList of tests performedName and contact details of person for emergencies (e.g. RSO)Record of ongoing relevant QA (e.g. wipe tests, activity verification)Any incidents (stuck source?)Any changes to licensing conditionsDecommissioning detailsDisposal details (name and license of the person/company the source was disposed to)


Part No...., Module No....Lesson NoPart 15: Security of sources, and disposal of disused sources Learning objectives: Upon completion of this lesson, the students will be able to:Be able to apply the concept of a radiation source to radiotherapyUnderstand how sources in radiotherapy can be made secureBe familiar with appropriate ways to dispose of sources in radiotherapy Activity: lectureDuration: 2 hours

IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe picture of flowers may be a bit surprising for the participants - this will hopefully increase attention. However, the lecturer could also point out some - admittedly somewhat tedious - similarities:the variety of sources (similar to flowers)need to know about them to get the best resultsIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThis is an important point - basically BSS applies to all sources in radiotherapy.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe features given here can be repeated for the next slide where a practical example is given...IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe picture shows a report issued by IAEAIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe figure shows a map of the affected area, indicating sampling sites. It is not important for the participants to get all the details of the map - the main message is that a large area was affected and that sampling involved air, water and soil.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoShown is a brisk skin reaction (desquamation) from handling the sourceIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThis slide summarises the magnitude of the accident in a different way. The lecturer can remind participants that this does not reflect the human costs illustrated in the previous slide.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoShown are 125-I seeds for prostate implants - the lecturer can point out again that the small size of the sources creates a potential for loss unless one accounts very carefully for all sources.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoCheck sources are also supplied with many survey meters. This is an illustration of sources of which many people are not aware of. The next slide provides more information.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoAn example only - but all therapy X-ray equipment should have a key system to prevent unauthorized use.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe best and most cost effective way is to exchange a source in which case the manufacturer should be required to take the old source.The picture illustrates a schematic drawing of a Cobalt unit with a source draw. More different mechanisms of source exposure design are shown on the next slide.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe details are not that important, the participants should be aware of the multitude of different designs.The lecturer could point out that each design has its own strong and weak point and both leakage radiation and source design and exchange depend on the unit design.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoExample of the safe for miscellaneous sources - shown already in part 14.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe main messages are already dealt with in part 14 of the courseIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThis is a central message - the lecturer should ensure the participants grasp its importance. The documentation must be verified and easily accessible for updates.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThese are just some of the tests or procedures performed with sourcesIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThese are just some of the tests or procedures performed with sourcesIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoAs a lost or unaccounted source can be a major safety hazard, the next four slides deal with some basic preparedness for this event.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe search in the toilet bowl indicates that one needs to follow typical pathways and be prepared for some lateral thinking.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIt is not important for participants to be able to read all labels - the message is that plans must be in place which identify the situation and end up with an action section which can easily be followed.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe picture is a reminder of the first part of the lecture where the accident in Goiana was discussed.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIn practice these are very important messages - due to a variety of circumstances many hospital still have sources which they cannot dispose of. This is not something which can be left alone as many of the sources concerned (60-Co, 137-Cs and Radium) are long lived and will continue to pose a hazard in many years. Participants should be encouraged to document the problem (if it exists) in their facility and try to actively address it. The IAEA offers advise on this.IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe exchange implies that the supplier of the new source will dispose of the old one...IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoLets summarize the main subjects we did cover in this session. IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoThe records should include:Name of authorized personLicensee and license conditionsWho ordered the source and whenSupplier (including address, license details and contact details)Source specifications (chemical form, Date delivered, received bySource certificateInstalled byList of tests performedName and contact details of person for emergencies (eg. RSO)Record of ongoing relevant QA (eg. wipe tests, activity verification)Any incidents (stuck source?)Any changes to licensing conditionsDecommissioning detailsDisposal details (name and license of the person/company the source was disposed to)

IAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation SourcesPart No...., Module No....Lesson NoIAEA Post Graduate Educational Course in Radiation Protection and Safe Use of Radiation Sources

Documents

Radiation Protection in Radiotherapy Part 15 Security of sources, and disposal of disused sources IAEA Training Material on Radiation Protection in Radiotherapy