Radiation Safety Awareness Training
WSU Radiation Safety Program
The WSU Radioactive Materials License is:
Issued by the Washington State Department of Health, DOH (Our Regulatory Authority)
– DOH issues Radiation Protection Regulations and Provides Radiation Machine Registration
Radiation Safety Committee
The WSU Radiation Safety Committee (RSC) establishes Radiation Safety Policies at WSU
The RSC is a presidential committee.
You can learn more about them here: Radiation Safety Committee
Authorized Users and Radiation Workers
Authorized Users:
-Are responsible for a safe and compliant research program
Non-radiation Workers:
– Need to be aware of hazards and hazardous situations and who to contact if there are questions or concerns
WSU Radiation Safety Office
The Radiation Safety Office (RSO):
-Implements Policies, Manages all aspects of the Radiation Protection Program Manages Services, and Ensures compliance with State regulations (WAC 246)
Our Regulatory Philosophy is: ALARA
“AS LOW AS REASONABLY ACHIEVABLE”
We also:
-Provide Periodic Inspections of Radiation (x-ray) Machines.
-Routinely inspect, survey and posts laboratories that use radioactive materials.
Website
Many of your radiation safety questions, can be answered at our web site.
What is Radioactivity ?
If an atom has too many or too few neutrons for a given number of protons, the nucleus will not be stable.
The unstable atom will try to become stable by giving off excess energy. This energy is in the form of particles or rays (radiation). These unstable atoms are known as radioactive atoms, or radioactive materials
Radiation vs. Radioactive Material
Radiation: ENERGY transported in the form of particles or waves (alpha, beta, gamma, neutrons)
Radioactive Material: MATERIAL that contains atoms that emit radiation spontaneously
Radiation vs. Contamination
Radiation is the energy that unstable (radioactive) elements emit. Exposure to radiation does not immediately make a person radioactive. For example, having an x-ray does not make you radioactive.
Radioactive contamination is radioactive material somewhere it shouldn’t be. For example, walking though some radioactive material in a lab. Now your shoes are radioactive (this is why we require lab surveys, to prevent contamination).
Campfire Analogy
In this example, the logs in the fire are the radioactive material. The energy emitted from the fire is in the form of heat. This energy can be compared to radiation.
Contamination occurs when burning ash from the fire lands on you. That ash is “radioactive material” where it should not be.
Non-ionizing vs. Ionizing radiation
Non-ionizing radiation refers to any type of electromagnetic radiation that does not carry enough energy to ionize atoms or molecules. Ionization occurs when an electron is completely removed from an atom or molecule.
Examples of non-ionizing radiation: microwaves, ultraviolet light, lasers, radio waves, infrared light, and radar.
Ionizing Radiation
Ionizing radiation consists of subatomic particles or electromagnetic waves that are energetic enough to detach electrons from atoms or molecules, ionizing them.
Examples of ionizing radiation: alpha particles, beta particles, neutrons, gamma rays, and x-rays.
Where Are Sources of Ionizing RadiationUsed at WSU?
Research Laboratories
Therapies and Imaging of Animals
at the Veterinary Teaching Hospital
Research Reactor
Natural Background Radiation
Different Sources of Ionizing Radiation Used at WSU
Radioactive Materials
These sources are always emitting radioactivity.
They decay away with time.
Rooms are posted with “Caution: Radioactive Materials” sticker.
Sealed sources – Radiation field but no contamination hazard.
Unsealed sources – Both a radiation field and a contamination hazard.
Radiation Machines
Machines only emit radiation when they are powered on.
Rooms are posted with a “Caution: Radiation Machines Sticker”
What is being Emitted from the Sources of Ionizing Radiation?
There are 4 distinct types of radiation.
- Alpha particles are helium nuclei (2 protons, 2 neutrons)
- Beta particles are high-speed electrons or positrons
- Gamma and X-ray radiation is a high-energy photon
- Neutron radiation are free neutrons
Alpha Particles
Physical Characteristics: Large mass, highly charged, helium nuclei (2 protons, 2 neutrons).
Range: 1-2 inches in air.
Shielding: Dead layer of skin, paper.
Biological Hazards: Internal hazard, alpha particles deposit large amounts of energy in a small amount of body tissue.
Beta Particals
Physical Characteristics: Small mass, about the size of an electron.
Range: Short distance (one inch to 20 feet).
Shielding: Plastic.
Biological Hazard: Beta Particles are both an Internal and External hazard, particularly to the skin and eyes.
Gamma Rays/X-Rays
Physical Characteristics: No mass. No charge. Electromagnetic wave or photon.
Range: Very far. Rays will easily go several hundred feet and have a very high penetrating power.
Shielding: High density materials like Concrete and Lead.
Biological Hazard: Pose a risk for whole body exposure. The hazard may be external and/or internal. This depends on whether the source is inside or outside the body.
Neutron
Physical Characteristics: Fairly large mass but no charge.
Range: Range in air is very far. Easily can go several hundred feet. High penetrating power due to lack of charge (difficult to stop).
Shielding: High hydrogen content materials such as Water, Concrete, and Plastic .
Biological Hazard: External whole body exposure.
Radiation is Around Us Always!
Annual Background Dose
Half of this dose comes from natural background radiation. Most of this background exposure comes from radon in the air, with smaller amounts from cosmic rays and the Earth itself.
The other half (310 mrem) comes from man-made sources of radiation, including medical, commercial, and industrial sources.
This level of radiation exposure has not been shown to cause humans any harm.
Natural Radiation
Natural radiation has always been an integral part of our environment. It has been with us since the earth was formed. It is as much a part of our every day environment as the light and heat of the sun’s rays.
Environmental Radiation Sources
Exposure to radiation from natural sources is an inescapable feature of everyday life in both working and public environments. The radiation we are exposed to comes from such natural sources as sunlight, soil, and certain types of rocks. Cosmic rays filtering down through the atmosphere, and radon gas filtering up through the soil, are sources of natural radiation. This radiation is called background radiation. It is present everywhere, all the time and varies greatly depending on our geographical location.
Coordination with Facilities
Occasionally Facilities may need to operate in a radioactive materials area or on a piece of equipment that contains or has contained radioactive materials
Situations Where the RSO and Facilities Operations Can Coordinate
Jobs involving areas or items where radiation hazards may exist.
1. Servicing Refrigerators
2. Servicing Ventilation Systems
3. Servicing Plumbing
4. General Housekeeping
General Approach to Items Needing to be Serviced
1. RSO is contacted regarding the need to service an item or an area.
2. If the room is a radioactive materials location then the authorized user is responsible to survey and clean the item.
3. The RSO performs a second survey to confirm that there is no residual radioactive contamination. At Non-Pullman campuses and Research Stations the RSO relies solely upon the authorized user. (The RSO will review the survey reports to confirm cleanliness.
4. The RSO posts a sign, survey report or a notice indicating that the item or area is clean.
Situations that are not routine: Call RSO!
1. Radiation Stickers in the non-radioactive waste container.
2. Water is discovered on the floor of a radioactive laboratory.
Release of Equipment For Repair or Surplus
Authorized users must decontaminate and survey each item of University equipment which has contained or may have been contaminated with radioactive materials prior to disposition.
The Radiation Safety Office (RSO) performs a property release survey prior to the transfer of such equipment to Surplus Stores or other release for unrestricted use.
After completing satisfactory radiation surveys, Radiation Safety Office personnel will remove all radioactive
materials labels or stickers.
(Non-RSO personnel shall not remove radioactive materials labels.)
Some Housekeeping Concerns
Waste Containers:
The Radiation Safety Office supplies all radioactive materials waste containers to users on campus, free of charge. For liquid waste there are one gallon jugs and five gallon jugs. Please do not use glass bottles for liquid waste. For solid waste there are one cubic foot boxes and two cubic foot boxes.
Boxes:
Outer Radioactive Materials shipping containers (boxes) may be discarded as NORMAL trash only after they have been surveyed and found free of contamination and have had all radioactive labels defaced.
Pigs:
Inner shipping containers (pigs) may also be discarded as NORMAL trash only after they have been surveyed and found free of contamination and had any and all radioactive labels defaced.
Except for ones that contain lead (Pb). Lead is a hazardous waste and can not be discarded in normal trash. These lead need to be picked up by EH&S. The Radiation Safety Office (RSO) only accepts contaminated pigs.
The blue pig is plastic, and can go in the regular trash after being surveyed.
The grey pig has lead lining, it needs to go to EH&S after being surveyed.
Or, contact Radiation Safety for Assistance!
(509) 335-7183
Radsafe@ad.wsu.edu
http://www.rso.wsu.edu/
