RADIATION SAFETY HANDBOOK

Transcription

1 Environmental Health and Safety s RADIATION SAFETY HANDBOOK University of Colorado Dept. of Environmental Health and Safety Health Physics/Radiation Safety 413 UCB 1 (2008)

2 Table of Contents EH&S Health Physics Important and Emergency Phone Numbers.. 6 Forward.. 7 Letter from Chancellor Peterson Chapter 1 - Introduction 1. Purpose of the Radiation Safety Handbook 9 2. Fundamentals of Radiation Safety.. 9 Background Radiation 9 Common Units... 9 ALARA.. 10 Time, Distance, Shielding.. 11 Chapter 2 - Laboratory Licensing 1. Introduction Laboratory Licensing. 12 New Licenses. 12 License Amendments. 13 License Renewal. 14 License Termination Responsibilities Laboratory Signs and Labels Laboratory Audits State Inspections 15 Chapter 3 - Radioactive Materials Management 1. Introduction Purchasing Radioactive Materials Delivery Address Storage of Radioactive Materials 17 2 (2008)

3 4. Use of Radioactive Materials.. 17 Designated Areas 17 Shielding Radioactive Materials Inventory Transfer of Radioactive Materials.. 18 Chapter 4 - Radiation Surveys 1. Introduction Contamination Surveys Area Surveys Survey Instruments Freezer Frost Surveys Equipment Transfer / Disposal / Resale Surveys Chapter 5 - Waste: Radioactive and Mixed 1. Introduction Waste Containers Restricted Materials Container Contents Sheets Radioactive Waste Pick-up Requests Sealed Source Disposal.. 26 Chapter 6 - Training 1. Introduction Basic Radiation Safety Training Refresher Training Laboratory Contact Training Support Staff Training (2008)

4 5. Sealed Source User Training X-ray Machine User Training Emergency Responder Training. 29 Chapter 7 - Sealed Sources 1. Introduction Storage of Sealed Sources.. 30 Tier I Sealed Sources.. 30 Tier II Sealed Sources Use of Sealed Sources Gas Chromatographs and Electron Capture Detectors Liquid Scintillation Counters Portable Gauges.. 32 Chapter 8 - Exposure Control 1. Introduction 33 Dose Limits. 33 Relative Risk Personnel Monitoring Dosimetry.. 34 Whole Body 35 Extremity 35 Embryo / Fetus Bioassay Environmental Monitoring. 36 Chapter 9 - Mishaps and Emergencies 1. Introduction Unsealed Radionuclide Spill Clean-up (2008)

5 Contamination in the Laboratory 38 Personnel Contamination 38 Ingestion / Inhalation of Radioactive Materials Leaking Sealed Sources High Radiation Exposure 38 Chapter 10 - X-ray Machines 1. Introduction Purchasing Analytical X-ray Devices 39 Summary of Part 8 Requirements.. 40 Equipment Requirements 40 Area Requirements. 40 Operating Requirements. 41 Personnel Requirements Medical (Human Use) X-ray Devices Security and Storage Transfers. 42 Glossary Appendices (2008)

6 IMPORTANT PHONE NUMBERS EH&S Health Physics Boulder Campus Environmental Health & Safety (303) EH&S Health Physics (Campus Hours) EH&S Health Physics FAX: (303) EH&S Health Physics EH&S Health Physics World Wide Web site: Colorado Springs Campus EH&S Health Physics (Campus Hours) UCCS Public Safety (719) EMERGENCY PHONE NUMBERS To report an emergency situation, please use the following contact information: Boulder Campus EH&S Health Physics (Campus Hours) Environmental Health & Safety (Campus Hours) (303) UCB Police Dispatch (After Campus Hours) 911 or (303) Colorado Springs Campus EH&S Health Physics (Campus Hours) Public Safety (After Campus Hours) (719) UCCS Police Department (After Campus Hours) (2008)

7 FOREWORD EH&S Health Physics The State of Colorado has entered into an agreement with the United States Nuclear Regulatory Commission (U. S. NRC) to govern the safe use of radioactive materials. The Colorado Department of Public Health and Environment (CDPHE) is responsible for implementing this agreement and for developing regulations which are at least as restrictive as those established by the U. S. NRC. The University of Colorado has a license from the State of Colorado, through CDPHE, to oversee the safe use of radioactive materials on the Boulder, Denver, and Colorado Springs campuses. This license requires, in part, that the University have a Radiation Safety Committee (RSC) and a Radiation Safety Officer (RSO). The RSC and RSO work together to ensure safety and regulatory compliance for individuals working with radioactive material or radiation; for the faculty, staff, and students of the University; and for members of the public. The Radiation Safety Committee essentially serves as the on-site regulatory agency for the University, and as such, has the authority to establish policies and procedures, provide enforcement sanctions, and restrict the use of radioactive materials and/or radiation. The RSC and RSO issue, amend, and terminate laboratory licenses, which authorize the specific activities associated with radioactive materials and/or radiation. The RSC is composed of members of the faculty and staff representing various departments and levels of experience with radioactive materials and radiation, as well as the Radiation Safety Officer. Each member is appointed through the University s Administration. Every effort is made to maintain representation from each of the departments that actively use radioactive materials in the course of their research and/or academic work. Membership also includes a representative from Administration. The Radiation Safety Officer is an individual approved by the State of Colorado who has the knowledge, responsibility, and authority to apply appropriate radiation protection regulations. The Radiation Safety Officer and Health Physics staff are members of the University of Colorado s Department of Environmental Health and Safety. These individuals provide daily management and support services for the safe use of radioactive materials and radiation. EH&S Health Physics works closely with the RSC to ensure safety and regulatory compliance, while striving to provide customer-friendly services which facilitate continued successful research and academic activities at the University of Colorado. Members of the RSC and the RSO may be contacted through EH&S Health Physics. We thank you for taking the time to read this Radiation Safety Handbook and hope that it proves to be helpful. We encourage and appreciate your comments and feedback. Sincerely, R. Jerome Peterson, Ph.D. Michelle S. Law, M.S. Radiation Safety Committee Chair Radiation Safety Officer 7 (2008)

8 INTRODUCTION EH&S Health Physics 1. PURPOSE OF THE RADIATION SAFETY HANDBOOK The University of Colorado Radiation Safety Handbook (RSH) is intended to be a user s guide for anyone working with radioactive materials and/or ionizing radiation. Radioactive materials and ionizing radiation include unsealed sources, sealed sources and x-rays. The RSH is required by the University s Radioactive Materials License. This chapter will address basic radiation safety concepts including some background information for reference use. It will also address the University s Radioactive Materials License, regulations, and inspections. 2. FUNDAMENTALS OF RADIATION SAFETY Radioactivity is defined as the spontaneous emission of radiation, generally alpha or beta particles, often accompanied by gamma rays, from the nucleus of an unstable atom. Radiation may be particles [alpha (α), beta (β), neutron (n)] or photons [gamma (γ), x-ray (x)] emitted from an unstable radioactive atom as a result of radioactive decay. All of these types of radiation are represented at the University of Colorado. Each type of radiation has unique safety considerations and handling techniques that will be discussed in this chapter. Background Radiation Radiation is part of everyday life. There are many sources of natural background radiation, both external and internal. External radiation sources include cosmic (beyond the Earth s atmosphere) and terrestrial (the Earth s contribution) radiation. Internal radiation sources include carbon ( 14 C), potassium ( 40 K), numerous other minerals which make up bones and soft tissues, and radon deposited in the lungs through inhalation. The average radiation dose from exposure to natural and man-made background radiation in the United States is approximately 3.6 msv (360 mrem) per year (see common units below and the glossary for an explanation of these units). As a rough estimate or rule of thumb, this value doubles for each mile of elevation gain. Therefore, living in Boulder, Denver, or Colorado Springs increases the average background dose to approximately msv ( mrem) per year. The increase is due to a higher contribution from cosmic radiation at higher altitudes and terrestrial radiation. Common Units There are many units used to describe activity, dose, dose equivalent, and exposure. In the United States, conventional units are still being used, although the complete conversion to the Systeme International (SI) units may happen in the future. At the present time, SI units are used in addition to conventional units on packages and radiation sources. At the University of Colorado, subdivisions of units such as millicuries (mci) and millirem (mrem) are used along with divisions of SI units such as megabecquerel (MBq) and millisievert (msv). Both conventional and SI are units are acceptable. 8 (2008)

9 The SI unit of radioactivity is the Becquerel (Bq) which is equivalent to one disintegration or decay per second. The SI unit of dose is a Gray (Gy) and the unit of dose equivalent is a Sievert (Sv), both of which are equivalent to 1 Joule per kilogram by definition. As mentioned previously, not all forms of radiation (α,β,γ, n, x) produce the same biological effect. For example, 1 Gray (Gy) of beta radiation is not equivalent to 1 Gray (Gy) of neutron radiation. However, 1 Sievert (Sv) of beta radiation is equivalent to 1 Sievert (Sv) of neutron radiation. The conventional unit for radioactivity is the Curie (Ci). One Curie is equal to 3.7 x nuclear disintegrations or decays per second. Other conventional units include the rad for dose and the rem for dose equivalent. Rad is an acronym for Radiation Absorbed Dose and rem is an acronym for Roentgen Equivalent Man. Dose equivalent was developed in an effort to incorporate biology into the physics of radiation exposure. Not all forms of radiation (α, β, γ, n, x) produce the same biological effect. For example, 1 rad of beta radiation is not equivalent to 1 rad of neutron radiation. However, 1 rem of beta radiation is equivalent to 1 rem of neutron radiation. Exposure is defined only for gamma or x- rays in air, not tissue. Roentgen (R) is the unit of exposure. Many radiation survey meters use units of milliroentgen (mr). Please refer to the Glossary for additional clarification of these terms. Systeme International (SI) Units Conventional Units Activity Activity 1 Bq = 1 disintegration / second 1 Ci = 3.7 x disintegrations / second 1 Bq = x Curies 1 Ci = 1000 mci 1 kbq = 1,000 Bq = x 10-8 Ci 1 mci = 1000 µci = x 10-5 mci 1 MBq = 1000 kbq = 1,000,000 Bq 1 mci = 37,000 kbq = 37 MBq = mci Dose Dose 1 Gy = 1 J / kg = 100 Rad 1 Rad = 100 ergs / gram = 0.01 J / kg 1 Gy = 100 centigray (cgy) 1 Rad = 0.01 Gy 1 cgy = 1 Rad Dose Equivalent Dose Equivalent 1 Sv = 1 J / kg = 100 Rem 1 Rem = 1000 mrem 1 msv = 0.1 Rem = 100 mrem 1 Rem = 0.01 Sv 1 mrem = 0.01 msv ALARA A common acronym used in radiation safety is ALARA, which stands for As Low As Reasonably Achievable. The ALARA philosophy attempts to incorporate physical, social, and economic factors in reducing doses to individuals. The University of Colorado has an ALARA program which is reviewed each year to evaluate efforts at keeping doses and exposures ALARA. It is the responsibility of each radiation worker to keep the dose to themselves and the people around them ALARA. Refer to Appendix A for a copy of the University s ALARA program. 9 (2008)

10 Time, Distance, Shielding Radiation doses may be reduced by taking advantage of time, distance, and shielding. By reducing the time spent working with radioactive materials and/or radiation producing machines, the dose received from the radiation is reduced. Increasing the distance from a source also will reduce the dose because the intensity of radiation decreases at approximately 1/d 2, where d is the distance from the source. For example, if the distance (d) is doubled, the intensity is reduced to ¼ (d 2 ) of the original intensity. This is also known as the Inverse Square Law. Shielding can be very effective in reducing the dose received. There are different types of shielding for different types of radiation. Use caution when selecting shielding to reduce the radiation dose. The dose may actually increase by selecting the wrong shielding. Verify radiation levels with a survey meter to ensure that appropriate and/or enough shielding has been used. Health Physics normally does not provide shielding to researchers. However, staff members are available to answer general shielding questions and discuss the efficacy of shielding materials. Remember: Time, Distance, and Shielding Doses can be minimized by taking advantage of the following simple methods: 1. Reduce the amount of time spent near the radioactive material/source 2. Increase the distance from the source 3. Use appropriate shielding whenever possible 10 (2008)

11 LABORATORY LICENSING 1. INTRODUCTION Most of the use of radioactive materials at the University of Colorado occurs in laboratories. Proper laboratory set up and licensing are essential to maintaining a safe working environment for personnel using radioactive materials and/or radiation. This section will address general laboratory safety requirements for unsealed radioactive materials, sealed radiation sources, x-rays, and lasers. It will also address the responsibilities of the Principal Investigator (PI) and individuals using radioactive materials and/or other radiation sources. 2. LABORATORY LICENSING The University of Colorado issues Radioactive Materials Licenses (License) to qualified PIs, also known as Authorized Users (AUs) or Licensees. Applications for a new license, license amendment, license renewal, or license termination may be obtained from Health Physics. Sample forms are included in Appendix B. A license must be obtained prior to working with radioactive materials and must be kept current. The Radiation Safety Committee (RSC) has established a renewal frequency goal of three years. A license will be issued with an expiration date reflecting the three year period. Licenses not amended or renewed within the three year period remain valid until an amendment or renewal is issued. New Licenses At least six (6) weeks should be allowed for processing applications. License requirements include laboratory contact information, radionuclide information and limits, experimental procedures, equipment to be used, waste information, and past training and experience. Laboratory contact information includes building location, offices, telephone numbers at work and at home, and campus box number. Radionuclide information includes radionuclide(s), amount of activity required for each experiment, and the physical and chemical forms needed. Experimental procedures should describe the experiment, operating procedures to be used for each radionuclide and a statement indicating whether or not biohazardous materials will be used with the radioactive materials. Operating procedures should include information to limit the spread of contamination, frequency of surveys, analysis methods such as liquid scintillation counters, and any special logistics required to complete the experiment. Equipment item information includes type, make, model, serial number(s), and location. For equipment that requires internal radiation sources and/or calibration sources, information also includes the radionuclide, activity, physical and chemical forms, manufacturer, and assay dates for the sources. 11 (2008)

12 Waste information should be broken into volume, approximate percentage of the total waste, and chemical constituents. All laboratories using unsealed radioactive material must perform contamination surveys, and will, therefore, generate scintillation vial waste upon analyzing the wipe smears. Please refer to the Radiation Survey chapter for more information. Biodegradable scintillation cocktails are strongly recommended whenever possible. Please refer to the Waste chapter for additional information. The Training, Education, and Experience sections refer primarily to the PI. These sections may be completed for additional laboratory staff if necessary. Dates should be provided as much as possible in these sections. Anyone using radioactive materials in a laboratory also must obtain training specific to the type of radiation used. Training is available by contacting Health Physics. Please refer to the Training chapter for additional information. A laboratory visit may be scheduled for new licensees upon completion of the application to review equipment, signs, use areas, and waste storage areas. The entire application and results of the laboratory visit are then submitted to the RSC for review and approval. New license applications may not be reviewed or approved by the Committee outside of their meetings, so please plan accordingly when submitting a license application. License Amendments Amendments are required for changing radionuclides, experimental procedures, and laboratory locations. When in doubt, contact Health Physics. At least three (3) weeks should be allowed for processing amendment applications. Amendments include verifying and updating laboratory contact information, radionuclide information and limits, experimental procedures, waste information, and past training and experience. See New Licenses section for clarification. New or different experimental procedures should describe the experiment and operating procedures to be used for each radionuclide. Operating procedures should include information to limit the spread of contamination, frequency of surveys, analysis methods such as liquid scintillation counters, and any special logistics required to complete the experiment. Waste information should be broken into volume, approximate percentage of the total waste, and chemical constituents for each new radionuclide and/or new procedure. All laboratories using unsealed radioactive material must perform contamination surveys, and will, therefore, generate scintillation vial waste upon analyzing the wipe smears. Please refer to the Radiation Survey chapter for more information. Biodegradable scintillation cocktails are strongly recommended whenever possible. Please refer to the Waste chapter for additional information. A new type of radiation may require additional training specific to the type of radiation used. Training is available by contacting Health Physics. Please refer to the Training chapter for additional information. 12 (2008)

13 A laboratory visit may be scheduled for amendments involving new or completely different procedures. The entire application and results of the laboratory visit are submitted to the RSC for review and approval. License Renewal Licenses are granted for an indefinite period, but after three years the Radiation Safety Committee may wish to review the license information. The Health Physics office will contact licensees whose licenses are up for renewal and review. This usually occurs after a license has been active with no amendments over a three year period. License requirements are reviewed and updated including laboratory contact information, radionuclide information and limits, experimental procedures, waste information, and past training and experience. A laboratory visit may be scheduled for renewals upon completion of the paperwork. The entire application and results of the laboratory visit are then submitted to the RSC for review and approval. Inactive Licenses Periodically, research using radioactive materials is put on hiatus but a licensee may wish to keep their license active. In this case, the licensee may request to be placed on inactive status. In this situation, all radioactive materials and waste must be removed from the laboratory through the Health Physics office. A final wipe survey will be performed on laboratory surfaces and equipment. After this, the Radiation Safety Committee will review the request and, if approved, the licensee will be released from regular license requirements such as training and surveying. If a licensee wishes to become active again within three years of going inactive, the Radiation Safety Committee can approve a re-activation. The license will be reviewed by the Committee as though it was an amendment. After three years on inactive status, a license will be terminated by the Radiation Safety Committee and the licensee will need to submit a new License application to resume work with radioactive materials. License Termination Termination is required for laboratories leaving the University of Colorado. If a laboratory is relocating or closing, the PI should contact Health Physics as soon as possible to facilitate proper relocation or disposal of the radioactive materials and closing of the laboratory. EH&S should also be contacted at (303) to facilitate proper relocation or disposal of non-radioactive materials. Termination may also be used for laboratories that are discontinuing work with radiation and/or radioactive materials. Contact Health Physics to facilitate proper termination and disposal of radioactive materials. 13 (2008)

14 3. RESPONSIBILITIES EH&S Health Physics PIs are responsible for the radiation safety program in their labs, including the following: overall supervision of work with radioactive materials, ensuring completion of basic and refresher training by all personnel, ensuring proper use and exchange of dosimeters when necessary, ensuring that contamination surveys are performed and properly documented, and ensuring compliance with all regulations and license commitments. Additionally, the PI must designate a Laboratory Contact. If the PI elects to be the Laboratory Contact, then an Alternate Safety Contact must be designated for emergencies. The Laboratory Contact is responsible for coordinating activities such as contamination clean-up (See Mishaps and Emergencies Chapter) and radioactive waste disposal (See Waste Chapter). Correspondence from Health Physics regarding lab practices will be sent to both the PI and the Lab Contact. 4. LABORATORY SIGNS & LABELS All entrances and doors to laboratories must have signs posted to warn users of hazardous conditions. For example, Caution Radioactive Materials, Caution X-ray Producing Equipment, Caution Lasers (various classes), and Emergency Notification Stickers are necessary for doors and entrances as applicable. Each laboratory must have a Notice to Employees posting. Additionally, all areas in a laboratory where radioactive materials are being used must be labeled clearly with Caution Radioactive Materials signs or stickers. This includes labeling equipment in which radioactive materials are used as well as equipment that contains radioactive sources. Equipment such as lasers and X-ray machines should be labeled clearly. These signs and stickers may be obtained from laboratory safety supply vendors or are available by contacting Health Physics at (303) LABORATORY AUDITS Health Physics performs periodic audits of each laboratory using radioactive materials. These audits review training, contamination surveys and other safety issues to ensure compliance with the laboratory's Radioactive Materials License and Federal, State and local regulations. Audits will be unannounced, but laboratories will be given an opportunity to complete a pre-audit checklist which will help reduce the time spent with the auditor in the field. Final audit findings are sent to the Licensee. Items of noncompliance and other concerns identified during the audit require a written response from the licensee which must include planned corrective actions. 6. STATE INSPECTIONS The University of Colorado is inspected by the State of Colorado to ensure compliance with the Rules and Regulations pertaining to Radiation Control. The inspections may occur at any time, but are usually once every 1-2 years. Most inspections include a review of records, interviews with personnel, and laboratory visits. Items of noncompliance must be corrected and may include enforcement sanctions. 14 (2008)

15 RADIOACTIVE MATERIALS MANAGEMENT 1. INTRODUCTION Management of radioactive materials and radiation is the responsibility of the Principal Investigator (PI) under whose license the material/machine is being used. Ultimately, however, it is the responsibility of each member of the laboratory to maintain safe storage and use of the radioactive materials and machines in their area. By using correct procedures to order, store, and dispose of radionuclides, sealed sources, and radiation producing machines, each researcher is helping to implement the ALARA Program and ensure safety at the University of Colorado. 2. PURCHASING To Receive Radioactive Materials and/or Radiation-producing Machines: 1. Ensure that the Laboratory License is obtained and includes the appropriate authorization for the radionuclide(s) or radiation-producing machine(s) 2. All deliveries must be through Health Physics (see address below) 3. All items must be purchased using a Purchase Request (PR) or Standing Purchase Order (SPO) 4. The University s Procurement Card or any other credit/debit cards are not permitted for these purchases 5. Exceptions to the above may be granted by the RSO on a case-by-case basis Laboratories wishing to order radioactive materials and/or a radiation-producing machine must first obtain a license for the specific product from the Radiation Safety Officer (RSO) and the Radiation Safety Committee (RSC). Radioactive materials will not be delivered to laboratories if the material will cause the license limit to be exceeded. If a limit is exceeded, a license amendment or disposal/removal of current inventory will be required and may prevent timely delivery. Please refer to the Laboratory Licensing chapter. The PI and laboratory staff members who will be using radioactive materials and/or radiation should complete Radiation Safety Training prior to ordering the product. If delayed, the required training must be completed prior to receipt of the product. Please refer to the Training chapter. Ordering radioactive materials and radiation-producing machines requires using a Purchase Request (PR)/Standing Purchase Order (SPO). In most cases, these are established by individual departments through the Procurement Service Center. All PRs and SPOs must be approved in advance by Health Physics. The Ship To address must be verified on all PRs. See Delivery Address below. The University s Procurement Card, other credit/debit cards, Memorandum Purchase Orders, and other 15 (2008)

16 purchasing methods may NOT be used to order radioactive materials or radiationproducing machines unless PRIOR approval is granted by the RSO or Alternate RSO. Exceptions may be granted on a case-by-case basis. All radioactive materials and sources must be delivered to Health Physics and checked for contamination prior to delivery to the receiving laboratory unless special arrangements have been approved in advance. Radionuclide stock vials contaminated at a level of 1,000 dpm/100 cm 2 or less will be delivered to the laboratory. Laboratory personnel will be notified of the contamination. Radionuclide stock vials contaminated at a level of 10,000 dpm/100 cm 2 or above will not be delivered to the laboratory. Exceptions may be granted by the RSO or her designee on a case-by-case basis. In the case of vials contaminated at a level above 1,000 dpm/100 cm 2 but below 10,000 dpm/100 cm 2, laboratories will be notified of the potential for contamination from the vial and reminded to use safe handing procedures. Laboratories have the right to refuse receipt of a vial contaminated at any level. It is the laboratory s responsibility to arrange for a replacement from the manufacturer if necessary. Radiation-producing machines and/or radioactive materials that are purchased, donated, received as gifts, or transferred from other institutions may be delivered to the area of use only after prior notification has been made to Health Physics. In most cases, delivery should be made through the Health Physics office. Radioactive Materials Delivery Ship To Address: University of Colorado at Boulder Environmental Health and Safety Center Health Physics 1000 Regent Drive, 413 UCB Boulder, CO ATTN: (PI s Name) 3. STORAGE OF RADIOACTIVE MATERIALS All freezers and other equipment used to store radioactive materials must have a Caution Radioactive Materials sign or label. Radioactive materials should be stored only in areas properly marked and approved for their use. Please refer to the Laboratory Licensing chapter or contact Health Physics at for further information. Each laboratory must ensure security of radioactive materials and/or radiation-producing machines. This may require locking of laboratory doors or storage freezers/refrigerators depending on use and accessibility of the area. Please refer to the Sealed Sources chapter for information on storage of sealed sources. 4. USE OF RADIOACTIVE MATERIALS Recommendations for the Safe Use of Radioactive Materials are provided in Appendix C. 16 (2008)

17 Designated Areas Radioactive materials should be used only in designated areas. All laboratories should designate an area(s) for eating and drinking. This area(s) should be as far as possible from any radiation work and should be the only area(s) in the laboratory where personnel eat or drink. Shielding Work with radioactive materials may require shielding. Appropriate shielding should be used for each experiment. For 32 P and other strong beta emitters, ¼ inch of plexiglas is appropriate. The use of lead for 32 P is discouraged because it produces Bremmstrahlung x-rays. Contact Health Physics for assistance in selecting appropriate shielding. 5. RADIOACTIVE MATERIALS INVENTORY Health Physics provides a Radioactive Materials Inventory to users of unsealed radioactive materials. See Appendix D for a sample Radioactive Materials Inventory form. This inventory should be kept on the outside of the main storage freezer/refrigerator/area in each laboratory. As a vial of radionuclide is used and disposed, the identification number on the outside of the pig should be crossed off the inventory. Enter the date and initials of the individual disposing of the item being crossed off the inventory. At least quarterly, the vials physically present in the freezer/refrigerator/area should be compared with the printed inventory to ensure accuracy. Vials which are no longer being used or have decayed too far for use should be placed in an appropriate waste container and removed from the inventory list. The inventory sheet is collected by Health Physics to update the laboratory s possession levels. It is a good practice to dispose of radioactive materials which are more than one or two years old, especially those bound to nuclides and proteins. Some bound radioactive materials and their chemical carriers have an effective shelf-life that may be exceeded. With certain long-lived radionuclides, especially tritium, the practice of periodically purging them helps reduce contamination problems in the storage area. Please refer to the Sealed Sources chapter for inventory of sealed sources. 6. TRANSFER OF RADIOACTIVE MATERIALS Radioactive materials or radiation-producing machines may be transferred to another appropriately licensed laboratory in the same building, following approval from Health Physics. If the recipient is not licensed for the material being received, a license amendment will be necessary prior to the transfer. See the Laboratory Licensing chapter. Transfers between buildings must be arranged through Health Physics to ensure safe handling and transport. The radioactive material, sealed source, or machine must be transferred to the license and included in the Radioactive Materials Inventory of the recipient. 17 (2008)

18 In order to send radioactive materials off-campus, the users should carefully package the material to avoid damage. Health Physics will address the radiation packaging requirements. Include a list of the package contents, name and address of the sender and receiver, Federal Express account number (if necessary), and any special instructions. Health Physics should then be contacted to arrange pick up, testing, and shipping. Radioactive materials are not to be shipped off-campus without prior approval of the RSO or the RSO s designee. Shipping costs will be paid by the laboratory wishing to ship the material. 18 (2008)

19 RADIATION SURVEYS EH&S Health Physics 1. INTRODUCTION Radiation Surveys are performed in areas where radioactive materials or radiationproducing machines are used to ensure that radioactive contamination and/or exposure levels are as low as reasonably achievable (ALARA). Contamination surveys are performed with wipe smear samples and are used to detect removable radioactive contamination, for example, radioisotopes such as 32 P or 35 S. Access to a liquid scintillation counter (LSC) or gamma counter is usually necessary to analyze wipe smear samples. Wipe smear samples analyzed with an LSC must have scintillation cocktail in the vial, preferably a cocktail that is biodegradable. Dry samples are not acceptable for contamination surveys. Area surveys performed with an appropriate survey instrument such as a Geiger-Mueller counter are used to detect exposure levels from either a removable or fixed source. Area surveys are performed in laboratories using x-ray machines or sealed sources, and should be performed in conjunction with contamination surveys in laboratories using unsealed radioactive materials. 2. CONTAMINATION SURVEYS All laboratories should be kept clean to avoid contamination. Laboratories using any unsealed radioactive materials are required to survey for contamination using a wipe smear. Surveys should be taken on a regular basis to detect any contamination occurring from radiation work. It is strongly suggested that weekly surveys be conducted, using wipe smears and a LSC. The results should be recorded in the Radiation Safety Survey Log. The Radiation Safety Survey Log may include an area map of the laboratory with survey locations clearly marked and the survey results. Results may be recorded on the Survey Log form or on copies of the area map and should include the date, location, and the name or initials of the person performing the survey, as well as the LSC print-outs. The Radiation Safety Survey Log should be stored in an easily accessible location for review by Health Physics and Federal, State, or local Inspectors. See Appendix E for a sample Radiation Safety Survey Log Form. Conducting Contamination Surveys The laboratory contamination survey should include equipment and work areas used during the experiment. For example, the survey should check floors (especially near waste containers, desks, and doorways); doorknobs; telephone receivers; buttons on equipment; hood sashes, edges, handles and switches; sink handles, edges, and drains; and lab benches. If a contamination level in an area is more than twice background, e.g. 100 cpm if the background is 50 cpm, decontaminate the area and re-survey. Continue this process until the area is clean (less than twice background). Record initial and final results in the 19 (2008)

20 Radiation Safety Survey Log. Contact Health Physics for assistance with areas that are not able to be decontaminated. Surveys should be completed each week that radioisotope is used to detect any contamination occurring from radiation work. A week is defined as 7 days beginning Sunday and ending Saturday. Each licensee using a common room is responsible for performing and recording surveys of the common room. An exception can be made by Health Physics staff regarding inter-laboratory agreements to conduct surveys of common rooms. Surveyors should use wipe smears and a LSC with scintillation cocktail or, for certain isotopes, a gamma counter to analyze the results of the survey. Surveyors are required to complete Radiation Safety training for unsealed isotope users, even if they are not actively working with radioactive materials in other lab protocols. If the laboratory is not using radioactive materials but is storing radioactive materials (including waste containers), monthly storage surveys are required. Storage areas should be surveyed at least once each calendar month. The results should be recorded in the Radiation Safety Survey Log with other laboratory survey results. Health Physics will perform secondary bimonthly contamination surveys or survey log audits in each licensed laboratory, as well as exit surveys of laboratory areas where work with radionuclides has been discontinued. If a laboratory is not surveyed by Health Physics, the laboratory may be asked to submit their survey results to Health Physics to show that it is free from contamination and that surveys are being conducted by laboratory staff. The secondary survey may include, but is not limited to, the following areas: floors (especially near waste containers and doorways); doorknobs; telephone receivers; buttons on equipment; hood sashes, edges, handles and switches; sink handles, edges, and drains; and lab bench edges. Laboratories will be notified if contamination levels exceed twice background. If the contamination level in an area is more than 1,000 dpm/100cm 2, the lab will be required to decontaminate and re-survey the area. Health Physics may resurvey the area, as well. See Appendix F for decontamination procedures. 3. AREA SURVEYS For high energy β and any γ emitters, area surveys are conducted with a portable (handheld) radiation survey meter in addition to routine contamination surveys. Area surveys are used to monitor for levels of increased radiation such as in unshielded areas or during relocation of radioactive materials. It is important to document a background radiation survey value for comparison to the measured radiation result. Laboratories using unsealed radioactive materials should perform area surveys periodically before, during, and after an experiment. A final survey after completion of the experiment may be performed, but does not eliminate the requirements for taking wipe smears for the contamination survey mentioned previously. Results may be recorded in the Radiation Safety Survey Log with the contamination survey results. Laboratories which use primarily radiation-producing machines and/or sealed sources should perform periodic area surveys using an appropriate survey instrument. This survey 20 (2008)

21 should be performed while the radiation-producing machine is on, in order to determine if there is leakage of x-rays. The results of the survey should be noted in a log and maintained in an easily accessible location for review by auditors. 4. SURVEY INSTRUMENTS Each laboratory using unsealed radioactive material other than 3 H or 14 C should either have two portable radiation survey instruments/meters or possess one instrument and have access to a second. This is to ensure availability of a survey instrument if one is damaged, out of calibration, or otherwise unable to be used. While appropriate survey instruments must be available for activities involving radiation at the University of Colorado, it is the responsibility of each laboratory to supply the instrument. Ideally, the instrument should read out in units of mr/hr and/or counts per minute (cpm) and the probe should be one which is most appropriate for the type of work performed in the laboratory. Health Physics is available to assist with appropriate instrument selection. Health Physics has a limited supply of loaner meters available for temporary use. Health Physics maintains a database of all survey instruments on campus and provides calibration services for most of the models used at the University of Colorado. Calibration is required at least once each year. Health Physics collects and calibrates the survey instruments every six months to ensure compliance with the annual calibration requirement. If a survey meter has not been calibrated within the last six months, contact Health Physics at. If a new instrument is obtained, contact Health Physics as soon as possible to have it placed on the calibration schedule. If an instrument requires major repairs or more complicated calibration techniques, it will be sent to the manufacturer for these services at the expense of the laboratory. Minor repairs may be provided by Health Physics at little to no charge to the laboratory. Additional repair costs may be recovered from the laboratory. Survey instruments/meters are calibrated to a National Institute of Standards and Technology (NIST) traceable 137 Cs gamma source. Correction factors are indicated on the calibration label for use with beta emitting radionuclides. When using β emitters, multiply the reading on the instrument by this correction factor to obtain an accurate reading. The following types of instruments are most commonly used on campus: Geiger-Mueller counter with thin-end window probe Geiger-Mueller counter with pancake probe Used for 32 P, 86 Rb, 125 I Used for 32 P, 33 P, 35 S These are available from several companies, including the following (Health Physics has catalogs and price lists available): Ludlum Instruments Eberline Victoreen (2008)

22 5. FREEZER FROST SURVEYS EH&S Health Physics Freezers used to store tritium ( 3 H), may be contaminated by the radionuclide due to hydrogen exchange with water. The escaped tritium ( 3 H) is then incorporated into the freezer frost (or condensation in a frost-free freezer) in the form of tritiated water (HTO). A heavily contaminated freezer could contain several millicuries of HTO in the frost. Freezers used to store tritium ( 3 H) are checked every six months by Health Physics personnel. Excessive contamination ( 10,000 dpm/100 cm 2 or dpm/ml) requires defrosting and decontamination of the freezer by laboratory personnel. Any liquid generated by defrosting should be considered radioactive liquid waste and collected for disposal through Health Physics. Paper towels used to blot liquid are considered solid radioactive waste. Please refer to the Waste chapter for additional information. Health Physics encourages laboratories to dispose of tritium ( 3 H) that is not being used. This will decrease the chances of freezer contamination. If a concern arises about excessive build-up of tritium ( 3 H) contamination in a storage freezer, call Health Physics at (303) to discuss techniques for reducing the contamination. See Appendix G for procedures for defrosting a contaminated freezer. 6. EQUIPMENT TRANSFER / DISPOSAL / RESALE SURVEYS Equipment such as refrigerators, freezers, centrifuges, and other laboratory items used with radioactive materials must be surveyed prior to transfer or disposal to assure that they are free from radioactive contamination. Refrigerators and freezers used for tritium, which may have become incorporated into the plastic of the unit, are two specific examples. Contact Property Services at (303) to transfer or dispose of equipment associated with radioactivity. A contamination survey of both the inside and outside of the unit will be required. Maintain the survey records, including LSC print-outs, with the contamination survey results in the Radiation Safety Survey Log. Once the unit is determined to be free from radioactive contamination, all radioactive signs and symbols must be obliterated or removed. Property Services uses an Equipment Disposal/Resale Certification Form that should be completed for transfer or disposal of large items. Please refer to Appendix H for a blank Equipment Disposal/Resale Certification Form. Equipment such as liquid scintillation counters which contain radioactive sources should have the source and any lead shielding removed by the manufacturer prior to disposal. Radiation-producing machines should have the x-ray tube removed and/or destroyed prior to disposal. All radioactive signs and symbols must be obliterated or removed. Contact Health Physics at for additional assistance with disposal of these items. 22 (2008)

23 WASTE: RADIOACTIVE & MIXED EH&S Health Physics 1. INTRODUCTION This Chapter will address the general requirements for handling waste in a radioactive materials laboratory. There are three different types of radioactive waste created in a radiation laboratory: 1) purely radioactive, 2) mixed (radioactive and chemical), and 3) radioactive and biological. Proper handling of wastes is critical for appropriate transportation and disposal. Numerous Federal, State, and local regulations impact waste; the Colorado Department of Public Health and Environment (CDPHE), the Department of Transportation (DOT), the Environmental Protection Agency (EPA) through the Resource Conservation and Recovery Act (RCRA), the University s Radioactive Materials License, and the City of Boulder. Mixed waste must comply with both radioactive and chemical regulations. Radioactive wastes are separated by waste type (solid, liquid, and scintillation vial) and by half-life. See section 2 of this chapter. Health Physics provides containers for all radioactive waste. When the containers are full, the laboratory submits a Radioactive Waste Pick-up Request Form to Health Physics. Health Physics then schedules a waste pick-up. See section 5 of this chapter. Mixed waste is separated by waste type and half-life in the same way as purely radioactive waste. Generation of mixed (hazardous and radioactive) wastes should be avoided whenever possible. Disposal of this type of waste is very difficult and costly. Laboratories should actively seek ways to reduce the amount of mixed waste generated. One example of a way to decrease a laboratory's mixed waste production is switching to biodegradable scintillation cocktail from flammable scintillation cocktail. Cost for mixed waste disposal may be re-charged to the laboratory at the discretion of the Radiation Safety Officer or her designee. Mixed waste generators must complete Hazardous Waste Generator Training as well as Radiation Safety Training. Please refer to the Training chapter for more information regarding Radiation Safety Training. More information on Hazardous Waste Generator Training is available at or the EH&S Generator s Guide to Hazardous Material/Waste booklet. Mixing biological wastes and radioactive material should be avoided whenever possible. Any biological material must be rendered non-infectious using bleach or other disinfecting agent prior to disposal with Health Physics. When radioactive material is involved, use of an autoclave is NOT permitted. Once rendered non-infectious, this waste should be segregated from all other radioactive wastes. Do not use biohazard bags for radioactive materials. If this type of waste is expected to be produced in the laboratory, contact Health Physics at for further guidance. 23 (2008)

24 2. WASTE CONTAINERS Radioactive waste is separated into three types: solid, liquid, and scintillation vials. Each type has specifically designated waste containers. Solid waste containers are available in two sizes, a twenty-gallon size which looks like a trash can, and a five-gallon size which looks like a covered metal bucket. Liquid radioactive waste containers are available in two sizes, a five-gallon, round plastic carboy not to be confused with the cube-like carboys used for chemical wastes, and a one-gallon, round plastic bottle. Smaller containers are available upon request for small amounts of liquid waste. Secondary containment tubs are available from Health Physics and are strongly recommended for liquid waste containers. Scintillation vials have only one size of waste container, a five (5) gallon covered metal bucket. This container looks the same as the small solid waste container. Care must be taken to avoid confusion between these containers. See section 4 of this chapter. Containers are also provided for sharps, lead pigs, and any other unusual wastes. Empty lead pigs are stored separately and collected upon request by Health Physics for possible recycling. Unlike lead pigs, plastic pigs may be disposed in the appropriate solid waste container. Call Health Physics at for special containers. Radioactive waste is also segregated by half-life. There are three half-life categories designated by color. The half-life categories are as follows: Yellow: P-32, P-33, Rb-86 and other radionuclides with half-lives < 60 days Orange: S-35, I-125 and other radionuclides with half-lives > 60 days but < 90 days Green: H-3 and C-14 and other radionuclides with half-lives > 90 days The yellow and orange categories are held for decay by Health Physics. Half-life categories are very important for waste minimization and decreasing disposal costs for the University. Waste should be segregated by half-life category whenever possible and placed in the appropriately colored waste container. If waste is created containing two or more isotopes from different half-life categories, the waste should be disposed in the container for the longest lived isotope in the waste. For example, waste containing S- 35 and C-14 should be placed in a C-14 waste container. Waste containers should be kept closed at all times, unless waste is actively being added. 3. RESTRICTED MATERIALS Keep in mind the following restrictions when disposing of radioactive waste: Sharps (glass pipettes, needles, scalpels, razor blades) must be placed in sharps containers designated for radioactive sharps and not in any other type of waste container. Sharps do not require segregation by half-life. Lead pigs should be collected in lead pig boxes available from Health Physics. 24 (2008)