Presentation on theme: "The Guiding Principle and Philosophy of Radiation Safety is:"— Presentation transcript:
1Radiation Safety Training ALARA Washington State University Radiation Safety Office
2The Guiding Principle and Philosophy of Radiation Safety is: ALARA(As Low As Reasonably Achievable)It is also a regulatory requirement!
3So what does ALARA mean ?ALARA is an acronym for As Low As Reasonably Achievable. This is a radiation safety principle for minimizing radiation doses and releases of radioactive materials by employing all reasonable methods.ALARA is not only a sound safety principle, but it is also a regulatory requirement for all radiation safety programs.
4What is the basis for ALARA ? Current radiation safety philosophy is based on the conservative assumption that radiation dose and its biological effects on living tissues are modeled by a relationship known as the “Linear Hypothesis”. The assertion is that every radiation dose of any magnitude can produce some level of detrimental effects which may be manifested as an increased risk of Genetic mutations and cancer.
5RADIATION DOSE/RESPONSE MODELS Two models: (1) Linear 2) ThresholdPreferred (Regulatory) model is Linear No-Threshold Dose Model:Conservative Hypothesis - For any dose, no matter how small, there is some effect, and as the dose is increased, the effect also is increased in proportion.Biological ResponseBiological ResponseDoseDoseThreshold
6How is ALARA Implemented ? An effective ALARA program is only possible when acommitment to safety is made by all those involved. Thisincludes the Radiation Safety Office staff, theRadiation Safety Committee, research faculty and allradiation workers. The WSU Radiation ProtectionProgram Manual provides the guidelines for theResponsibilities and good practices which are consistentwith both the ALARA concept and the regulatoryrequirements of the Washington State AdministrativeCode (Title 246 Chapter ).
7WSU radiation safety program. The WSU radiation safety program attempts to lower doses received by radiation workers by utilizing practical, cost effective measures.
9With the 4 basic Radiation Protection Principles. TimeDistanceShieldingContamination Control
10TIME EXPOSUREDecreasing the amount of time near the source decreases your exposure.
11How do you decrease your time exposure? Plan and Set Up Your Experiment Before Using Radioactive Materials.Perform Dry Runs - (Use NO Radioactive Material).Practice Handling Techniques (pipetting/aliquotting).Work Quickly but Safely.
12Increasing the distance from the source decreases your exposure. DISTANCE EXPOSUREIncreasing the distance from the source decreases your exposure.
13Attenuation of Radiation Intensity with Distance Increasing the distance from a source from 3 feet to 10 feet reduces the radiation intensity by 91%. Increasing the distance from a source from 3 feet to 32 feet reduces the radiation intensity by %. Increasing the distance from a source from 3 feet to 60 feet reduces the radiation intensity by %.
14Inverse Square Law 1/(distance)2 If you double the distance from a point source of radiation, the exposure is reduced to ¼ the intensity at the closer distance.I1 (100 mR/hr)D1 (1 meters)I2(?)D2 (8 meters)Given: I1 = 100 mR/hrD1 = 1 metersD2 = 8 metersI2 = (d1)2 X I1(d2)2= 1.6 mR/hr
15SHIELDING EXPOSURE Increasing the amount of shielding decreases your exposure.
16Proper thickness and appropriate materials are critical to shield you from a radiation hazard. Shielding Examples
17SHIELDING Appropriate Shielding Using Storage Containers (pigs) High "Z" Materials (Pb) for photonsLow "Z" Materials (Acrylic or Plexiglas) for beta radiationUsing Storage Containers (pigs)Shipping Containers from RAMSuppliersUsing Local Shielding (Plexiglas L-Blocks & Pb - Bricks)Using Vial & Syringe Shields –Balance between shielding and time. (If it takes a long time toinsert RAM into a shield it may not be ALARA!)
18CONTROLLING EXTERNAL HAZARD TIME: Radiation dose is proportional to theduration of the exposure.DISTANCE: Radiation dose is proportional to 1/(Distance)2.SHIELDING: Radiation dose is determined bythe type and thickness of shielding materials used.Correct selection of Shielding Materialsare a function of type and energy of radiation.
20By Contamination Control The major hazard for most radioactive materials on the WSU campus comes from internalizing the radioactive material.Once the radioactive materials are inside your body, you lose all the protections from TIME, DISTANCE AND SHIELDING.Contamination Control is the key to preventing internalization of radioactive materials.
21Radionuclides can enter the body in four ways. Inhalation, ingestion, absorption through the skin and wounds.
22Contamination Control Protect YourselfAlways use protective clothing.Lab CoatGlovesEyewearRequired by WACWear gloves properly.Lab Coats can be very fashionable. But always wear long pants and full shoes. The hat is optional.Don’t dress like this guy!
23CONTAMINATION CONTROL Always WEAR your lab coat and gloves, including appropriate leg and foot covering.Required by WACWear safety glasses/goggles or a face shieldwhen working with unsealed RAM. Theseprecautions are especially important whenthere is a splash potential.
24CONTAMINATION CONTROL (continued) CHANGE gloves frequently and REMOVEthem when leaving the lab and dispose ofthem as radioactive waste. To control crosscontamination of yourself, others andother research items.
25Protect OthersIf you contaminate your lab partners. They will not be happy with you.Label your radioactive work area.Required byWAC
26Protect Others (cont.)Label containers and tools used in radioactive work.Required byWAC
27Contamination Control (cont.) Protect Facilities and EquipmentCover all radioactive work areaswith absorbent paper, includingany transfer trays or secondarycontainers.Required by WACTape off the work area.Check for Contamination(do surveys)
28CONTAMINATION CONTROL (continued) Store and transport liquid radioactive materials in SECONDARY CONTAINERS, with the capacity to contain potential spills.USE DOUBLE CONTAINMENT –
29FOOD and DRINK The presence of empty food and drink NO eating, drinking, smoking, or chewing in the radioactive work space. (Internal contamination)Do not store food, drink or personal effects in any area, container, or refrigerator designated for radioactive materials use or storage. Required by WACThe presence of empty food and drinkcontainers in the lab will constitutea violation of regulations, since it willbe inferred that consumption occurredon the premises.
30CONTAMINATION CONTROL (continued) NO mouth pipetting. (Internal contamination)Required by WACMONITOR hands, clothes and work areafrequently during and after each use.Always WASH handsat the completion ofradioactive work.
31ADDITIONAL RADIATION SAFETY PRECAUTIONS Work with volatile compounds in a CERTIFIED OPERATIONAL fume hood. The hood must also be labeled for radioactive materials use.- Operational parameters of the fume hoodmust be verified before you begin yourradioactive work.
32CONTROLLING INTERNAL HAZARD To minimize the uptake of radionuclides into the bodycontrol the “Routes of Entry”Inhalation: Use of fume hood, gloved boxes.Gases and vapors in experiments.Radioactive spill of volatile compounds.Opening of sealed vials.Ingestion: No eating, drinking, chewing, smoking orapplication of cosmetics in radioactive laboratories.Use of gloves (preferably double gloves).No food in radioactive refrigerators.Washing hands, do monitoring.Prohibit mouth pipetting.Absorption: Wear protective clothing (lab coat, full shoes; be aware of loose sleeves of lab coat).
33On November 1, 2006, Alexander Litvinenko suddenly fell ill and was hospitalized.
34He died three weeks later of polonium-210 induced acute radiation syndrome. The median lethal dose for polonium-210 is around 238 μCi or 50 nanograms in the case of ingestion. The polonium-210 was in his tea.
35Keep radioactive materials out of your body. Polonium-210 is an alpha emitter. As we have seen in another module, alpha radiation is the highest internal hazard. If Mr. Litvinenko had not ingested the polonium it would not have been a radioactive hazard to him. The alpha radiation emitted by the polonium would not have penetrated the layer of dead skin on his body.So keep your lab clean Do your surveys.NO eating, drinking, smoking, or chewingin the radioactive work space.Do not store food, drink or personaleffects in any area, container, orrefrigerator designated for radioactivematerials use or storage.
36Test Time! Follow this link to the test. https://myresearch.wsu.edu Use your WSU user name and password to sign in.Click on the training tab.Then click on the available training tabFind the radiation safety training alara course, in the OR section, click on it and take the test.