Radiation Safety Refresher Training Radiation Safety Program University of Wisconsin - Milwaukee

Properties of Radiation Radioactivity is the natural property of certain nuclides to spontaneously emit energy, in form of ionizing radiation, in an attempt to become more stable. Ionizing radiation has the ability to remove electrons from atoms, creating ions. Ionization is the product of negatively charged free electrons and positively charged ionized atoms

Forms of Ionizing Radiation Ionizing radiation includes emissions with energies greater than 20 electron volts that cause ionizations when interacting with matter. Sources of ionizing radiation used at UWM include: Particulate Radiation Alpha Beta Photon Radiation Gamma X-Ray

Particulate Radiation ALPHA RADIATION Consists of two protons and two neutrons (helium nucleus) Massive size, moving at 80% the speed of light - Internal Hazard BETA RADIATION Consists of an electron Very small size moving at up to 99% the speed of light Hazard depends on decay energy of isotope

Examples of Beta Emitters H-3: Energy max = 19 KeV Internal Hazard C-14: Energy max = 160 KeV Internal Hazard S-35: Energy max = 170 KeV Internal Hazard P-32: Energy max = 1700 KeV Internal and External hazard The lower energy beta emitters are less penetrating and present less of a hazard. The concerns with these isotopes is primarily associated with internal exposure due to ingestion, inhalation, or skin absorption Higher energy beta emitters are more penetrating and present both internal and external hazards

Photon Radiation GAMMA RADIATION X-RAYS A wave radiation consisting of a photon Travels at the speed of light Created in the nucleus of the atom X-RAYS A wave radiation consisting of a photon Travels at the speed of light Created in the electron shell of the atom

Examples of Gamma Emitters I-125: Energy max = 35 KeV Internal/External Hazard Cs-137: Energy max= 662 KeV Internal/External Hazard Gamma Emitters have no mass and are very penetrating All gamma emitting isotopes and are considered both internal and external hazards

Units of Radioactivity The Becquerel (Bq) - International Unit 1 Bq = 1 disintegration per second 1 MBq = 1,000,000 disintegrations per second 1 GBq = 1,000,000,000 disintegrations per second The Curie (Ci) – Commonly used in the United States 1 Ci = 3.7E10 disintegrations per second 1 Ci = 2.2E12 disintegrations per minute 1 Ci = 1000 millicurie (mCi) = 1,000,000 microcurie (uCi) 1 Bq = 2.7E-8 mCi

Units of Radioactivity The RAD is the unit commonly used in the United States for Absorbed Dose (D) It is determined by the Energy that is actually deposited in matter 1 Rad = 100 ergs of deposited energy per gram of absorber Gray International Unit for Absorbed Dose 1 Gray = 100 Rads

Units of Radioactivity REM The REM is the unit commonly used in the United States for the Dose Equivalent Determined by Multiplying the absorbed dose (D) times a quality factor (Q) Q equals 1 for beta, gamma and x-rays, 5-20 for neutrons, and 20 for alpha Sievert International Unit for absorbed dose 1 Sievert = 100 REM

Half Life The half life of a materials is the time required for 1/2 of the radioactive atoms to decay The half life is a distinct value for each radioisotope

Half Life of Selected Radioisotopes Fluorine-18: 109.8 minutes Phosphorus-32: 14.3 days Tritium: 12.3 years Carbon-14: 5,730 years Uranium: 4,500,000,000 years

Example of Half Life You receive a shipment of 250 µCi of P-32 The half life of P-32 is 14.3 days If you do not use the P-32 until 14.3 days after receiving the material, you will only have 125 µCi remaining If you wait 28.6 days, you will only have 62.5 µCi remaining Shipment After 14.3 days After 28.6 days

Example of Half Life It is important to consider the half life of the radioisotope when planning a study that includes the use of radioactive materials

ALARA Primary goal of radiation safety is to avoid any unnecessary radiation exposure and to keep all exposure As Low Reasonably Achievable

aLARA Reducing the dose from any source radiation exposure involves the use of three protective measures: TIME DISTANCE SHIELDING

Time The amount of exposure an individual accumulates is directly proportional to the time of exposure Keep handling time to a minimum

Distance The relationship between distance and exposure follows the inverse square law. The intensity of the radiation exposure decreases in proportion to the inverse of the distance squared Dose2 = Dose1 x (d1/d2)2

Shielding To shield against beta emissions, use plexiglass to decrease the production of bremsstrahlung radiation. To shield against gamma and x-rays, use lead, leaded glass or leaded plastic

Internal Exposure Only a few commonly used radionuclides at UWM present an external exposure potential All radionuclides present a potential for internal exposure if taken into the body. Entry into the body can occur by inhalation, ingestion, or absorption through the skin

Minimizing Internal Exposure Good lab practices will help minimize the chance of contamination. Wear personal protective equipment If required, use a fume hood when working with volatile substances in a certified hood No eating, drinking or applying cosmetics Clean up spills promptly Routinely monitor work area Secure radioactive material

Personal Protective Equipment (PPE) Using PPE along with time, distance, and shielding will ensure that exposure is kept as low as reasonably achievable (ALARA). Laboratory coat Gloves Safety Glasses Dosimeters Close-toed shoes Full length pants

Dosimeter Required when there is a possibility of receiving greater than 10% of exposure limit Monitors for gamma, x-ray and high energy beta Worn for 3 months These are individual specific - Do not loan out Return promptly after receiving a new one Exposure reports are provided annually or at your request

Ring Dosimeter Monitors exposure to the hands Used for high energy beta, gamma and x-ray radiation Worn when handling > 500 µCi of P-32 or high energy gamma emitters

Safe handling of radioactive materials When working with radioactive materials, users should: Prepare your radioactive materials work area in the lab Cover work area with absorbent paper Set up radiation shields Ensure that radioactive waste containers are available Turn on survey meter and place adjacent to work area

Safe handling of radioactive materials Survey radioactive material work areas before, during, and after handling Survey common areas and frequently touched objects such as desk areas, computer keyboards, mice, door knobs and light switches Perform personal contamination surveys Scan gloves frequently during experiments Monitor whole body before leaving laboratory

Survey Instruments Geiger-Mueller Detector Used for beta, gamma and x-ray emitters Best for P-32, S-35 and C-14 Will detect I-125 and Cr-51 Sodium-Iodine Detector Detects gamma and x-ray emitters I-125 and Cr-51 Do not use to detect beta emitters

Survey instruments Operational Check Check calibration date Confirm calibration date within past year Check batteries Check response to radioactive source to confirm that the meter is operational

Spill Response Notify people working in the laboratory Control access to the affected area Wear gloves, lab coat, and safety glasses Clean spill from the outer perimeter inward Place clean up materials in appropriate radiation waste container After initial clean up, monitor for contamination Repeat process if contamination remains Call Radiation Safety (414-430-7507) if you need help, if the spill is greater than 100 µCi or the spill is in a public area Document the spill, contact Radiation Safety Spill kits are located in all radioactive labs Notify Radiation Safety of any conditions or practice that you think may be unsafe

Decontamination of Skin If the radioactive material is a high energy beta, gamma, or x-ray emitter, monitor with a survey meter and record reading Gently wash the affected area for 15 minutes with lukewarm water and a mild soap If you continue to find contamination, repeat washing and monitoring for up to 3 times Record final survey meter readings Contact Radiation Safety at 414-430-7507

Radioactive Materials License UWM has a Limited Scope Academic License All requests for use of new radionuclides or to become a new Authorized User should be submitted to the Radiation Safety Department at UWM. Rad Safety will then submit that information to the Department of Health Services (DHS) for approval. Approvals from DHS may take 3-4 weeks.

Ordering Radioactive Material All orders must be approved by Radiation Safety Notify Radiation Safety when you plan to place an order. This will ensure that there is appropriate coverage to receive the package. All radioactive material packages must be shipped to the Radiation Safety Office. That address is: University of Wisconsin – Milwaukee Attn: K. Axtman, Radiation Safety 3209 N. Maryland Avenue, Lapham Rm 181 Milwaukee, WI 53211 Once received by the RSO the material will be surveyed and inventoried and then released to the laboratory

Radioactive Waste Disposal Minimize generation of waste Identify and segregate waste - long term (H-3 and C-14) - intermediate (S-35 and I-125) - short lived (P-32) Complete disposal forms and maintain with your lab records Do not dispose radioactive waste down the drain.

Segregate your Radioactive Waste and do not mix with Hazardous Waste Do Not Mix Waste Types Do not place scintillation vials into dry solid waste containers Do not place dry solid waste into liquid scintillation vial waste Do not place liquid waste container into dry solid waste containers Segregate your Radioactive Waste and do not mix with Hazardous Waste

Radioactive Waste Containers DO NOT dispose of radioactive waste in: - medical waste containers - general waste Use only approved radioactive waste containers supplied by Radiation Safety which contains a warning label “Caution Radioactive Material”

Scintillation Vials Place in a separate container from the dry solid radioactive waste Separate scintillation vials containing long lived isotopes (H-3 and C-14) from those containing shorter lived isotopes (P-32, I-125) Ensure the lids are secured tightly on the bottles Do not overfill the container Complete a Radioactive Waste Form and contact Radiation Safety when container is full

Contaminated Sharps Syringes Pasteur Pipettes Scalpel Needles Radioactive sharps must be segregated from other radioactive waste and placed in a radioactive materials labeled sharps container.

When Working with Low Energy Beta Emitters Examples: H-3, C-14, S-35, P-33 Have access to a liquid scintillation counter Use a GM survey meter only for large quantities of C-14, S-35 and P-33 Isolate, label, and dispose of waste Secure material when not in use

When Working with High Energy Beta Emitters (P-32) Wear whole body dosimeter and extremity dosimeters if required Handle material behind a Plexiglas shield Regularly monitor work area and gloves for contamination Isolate, label, and dispose of waste Secure material when not in use Use Plexiglas shielding for storage

Working with Gamma or X-ray Emitters Minimize time handling material; use remote handling devices as necessary Wear whole body dosimeter and extremity dosimeters if required Regularly monitor work area and gloves for contamination Isolate, label, and dispose of waste Secure material when not in use Store sources behind lead shielding

Security Areas where radioactive materials are opened, used, or stored must either be locked, or be under constant surveillance by trained radiation workers. If an inspector can, at any time, gain access to a radioactive materials lab and discover radioactive materials in any form, without being confronted and asked for identification, then a violation has occurred.

Security Radioactive materials should be stored in locked refrigerators, freezers or storage units. If workers who are not trained and authorized to work with radioactive materials have access to the storage unit, the radioactive material should be stored in locking boxes that are secured.

BUT WAIT, THERE’S MORE… Training This completes your ANNUAL Radiation Safety Refresher Training (quiz on next slide). If you have any questions, please contact the Radiation Safety office at: 414-430-7507 or axtman@uwm.edu 414-229-6339 University Safety and Assurances Office University Safety and Assurances Website http://uwm.edu/safety-health/rad/ BUT WAIT, THERE’S MORE…

Click here for RAD Safety QUIZ Radiation Safety Quiz To receive credit for this training, please complete the following short quiz… Click here for RAD Safety QUIZ