Radiation Safety Training for Uranium and Thorium Compound Users

1. Radiation Safety Training for Uranium and Thorium Compound Users

2. Radiation Safety Training for Uranium and Thorium Compound Users • This radiation safety presentation is specific to people who use uranium and thorium compounds, such as uranyl acetate or thorium nitrate. It is not intended for people who plan to use other radioisotopes or uranium and thorium in quantities greater than grams to a few hundred grams. • EHS provides these training materials for the use of UCI faculty, staff and students to meet training needs specific to UCI. • The Radiation Safety Department of the Environmental Health and Safety (EHS) Department provides oversight for the use of Radioactive materials at UCI. • The Radiation Safety Division at UCI can be reached by calling 949-824-6200 or sending an email to radsafety@uci.edu.

3. Regulations • The use of uranium (U) and thorium (Th) compounds does not require the same level of control required for most radioisotopes. • Under Nuclear Regulatory Commission, uranium and thorium are defined to be “Source Material.” Typically an institution must have a specifically-issued Source Material License to possess U & Th. UCI has a radioactive materials license that allows a certain amount of Source Material to be on campus. • The Nuclear Regulatory Commission has determined that the hazard associated with the use of these U and Th compounds is small enough that the material can be sold without special controls on who may buy these compounds and without special requirements and precautions for using these materials.

4. Radiological Characteristics of U & Th Compounds • This training presentation provides an overview of the radiological properties of U and Th compounds and does not provide detailed information about radiation properties and effects. • If you’d like to read information about the characteristics of alpha, beta and gamma radiation, terms such as half-life, how radiation dose is measured, or a detailed description of the biological effects and risks of radiation exposure. • External radiation exposure occurs when a source of radiation is placed near your body. For example, if you are sitting near a bottle of uranyl acetate, you will be exposed to those beta and gamma radiation radiations that penetrate the sides of the glass bottle. The next slides will provide more detailed information about dose rates.

5. Radiological Characteristics of U & Th Compounds • The surface dose rate on contact with a 100 gm glass jar of uranyl nitrate is typically 0.15 mrem/hr. • One hundred grams of unshielded uranyl acetate powder, outside a bottle, has a maximum dose rate of 0.6 mrem/hr. Imagine that you are working with 25 grams and are 10 cm away from the powder. The maximum dose rate at this position is 0.15 mrem/hr. At 1 meter from the powder, the dose rate would be 1.5 μrem/hr. • The dose rates associated with thorium compounds are not significantly different. • The next slide will discuss the significance of these dose rates.

6. Radiological Characteristics of U & Th Compounds • Background radiation from natural sources of radiation such as cosmic rays, radon, and naturally-occurring radioactive materials in our environment and our bodies is always present. In the U.S. the average person receives an annual dose of approximately 300 mrems from these natural sources. • Using the dose rate information from the previous slide: Working with 25 grams of uranyl acetate powder for 10 minutes at a distance of 10 cm will produce a total dose of approximately 0.025 mrems. How does this compare to other radiation dose figures? • The federal annual limit for radiation exposure is 5000 mrem so the exposure received by people working with U and Th compounds is extremely low. • If you only work with dilute solutions of U and Th compounds or small gram quantities, there is no reason to be concerned about limiting your radiation exposure.

7. Radiological Characteristics of U & Th Compounds • The only concern is limiting exposure from the main stock of uranium or thorium in the bottles supplied by the vendor. Although the dose rates from these bottles are not directly hazardous, it is good radiation protection practice to minimize radiation exposure whenever practicable. • It is easy to decrease dose rate by moving away even small distances further away from the vendor bottles. • Store the vendor bottles of U and Th compounds in locations that are not directly adjacent to frequently occupied areas. For instance, don’t store the bottles next to your desk or on a shelf that is immediately adjacent to where you work. Since metal will provide some shielding, it might be useful to store the bottles in a closed metal cabinet.

8. Radiological Characteristics of U & Th Compounds • The doses you will experience during routine use of U & Th compounds will be very low, especially since most of your work will involve dilute solutions of uranium or thorium, and it won’t be necessary to regularly or extensively handle vendor bottles of U or Th. • It should also be noted that the external radiation is not sufficiently penetrating to present a hazard for pregnant women. • IMPORTANT - U and Th compounds exhibit the toxic properties of heavy metals and are more hazardous based on their chemical properties than their radiological properties. Follows your Procedures and comply with your chemical hygiene plan to reduce the risk of chemical exposures.

9. UCI Requirements • To possess U and Th compounds on campus you must have a Radiation Use Authorization (RUA) granted to your principal investigator by the Radiation Safety Division. • An RUA is a document that instructs users of these compounds how to handle them safely. • RUAs have detailed instructions on how to handle waste, where the compounds can be stored and used, how much of each compound you can have in your lab at one time, and how to monitor for radiation if necessary.

10. UCI Requirements • It is very important to keep in mind that even though you can easily buy these compounds, you MUST have approval by the Radiation Safety Division prior to placing the order. • In addition, ALL orders of radioactive material must be sent to the address below so they can be received and controlled properly. UC Irvine EHS/Radiation Safety ATTN: (Name of Principal Investigator) 4600 Health sciences Road Irvine, CA. 92697-2725

11. UCI Requirements • Vendor bottles of uranium and thorium compounds must be disposed of as radioactive waste. EHS will supply you with appropriate radioactive waste containers. • Other U or Th wastes such as microscope slides, used gloves, and wipes need to be handled as radioactive waste.

12. UCI Requirements • The Radiation Safety Division will provide a waste box for the disposal of all dry items contaminated with U or Th compounds. • Contact the Radiation Safety Division when the box is full to arrange for pick up and disposal. • If liquid waste is to be generated, contact the Radiation Safety Division for instructions.

13. UCI Requirements • U and Th compounds must be stored in a secure and designated place when not in use. This designated place will be labeled to indicate that radioactive materials are inside. • Storage areas should be controlled at all times by locking the room door or storage cabinet when unattended.

14. Safe Use of Uranium or Thorium Compounds • When handling radioactive materials, ensure you are wearing the proper personal protection equipment. Safety glasses, lab coat, nitrile gloves and closed toed shoes are required. • For items that are easily contaminated, such as pipettes, use equipment that is used exclusively for U or Th work. • Make sure that your work area is clearly labeled any time radioactive materials are present. Label contaminated items & equipment such as fume hoods.

15. Safe Use of Uranium or Thorium Compounds • If you are working with a liquid solution, cover the work surface with absorbent bench paper. • If the compounds are used in powder form, ensure they are handled in a properly working fume hood. • Follow Standard Operating Procedures at all times to ensure all safety steps are followed. • If a spill occurs contact (4-6200) the Radiation Safety Division immediately for assistance.

16. Safe Use of Uranium or Thorium Compounds • In the Event of Skin Contamination • Contact the Radiation Safety Division Immediately at extension 4-6200. • Wash skin with mild soap and lukewarm water for 2-3 minutes. • Do not use abrasives, organic solvents, and highly alkaline soaps to clean your skin. • These simple step of gently washing your skin should be sufficient to remove all contamination.

17. Conclusion • If you have any questions on this training please contact the Radiation Safety Division at 4-6200 or radsafety@uci.edu. • Please completed the training completion form in the link below and send it via email to radsafety@uci.edu or send it via office mail to ZOT STOP 2725. • http://www.ehs.uci.edu/programs/radiation/forms/uranium_thorium_compounds-radiation_safety_training_completion_form.docx