Ohio University Lab & Rad Safety Newsletter Winter 2018

Transcription

1 Ohio University Lab & Rad Safety Newsletter Winter 2018 Table of Contents Laser Training Summary... P.2 Regulation of Radioactive Materials... P.3 RADTown USA... P.4-5 = Required = Optional Alan Watts Director, Radiation Safety Officer Editor: Maria Stroia 1

2 Laser Training Summary (Controls found on the Laser) Remote interlock connector: This cable is used to connect an area away from the laser (EX: control room). If either end of the cable gets detached or the cable is cut/damaged, the laser will automatically lose power and shut off. Back view of laser Key control: The correct key must be inserted and turned to the on position to allow the laser to be turned on. This security measure helps prevent unathorized use of the laser. Housing interlocks: These act as safety switches. When the housing is on correctly (preventing unwanted light/ energy to escape) a circuit is formed. When the circuit is broken, the power is cut to the laser, shutting it off. Protective housing: A case covers the internal laser components to ensure that only the concentrated laser beam is exposed (it exits the housing through a hole near the partially reflective mirror Laser shutter: A moveable barrier right where the laser exits the protective housing, used to terminate the beam. Front View of laser The following diagrams are meant to help the reader understand common controls found on lasers, and engineering controls typically found on or near the laser itself. Laser indicator light: This light, located on top of the protective housing, is on whenever the laser is on/receiving power Side View of laser Top View of Laser 2

3 Regulation of Radioactive Materials Because of their potentially hazardous properties, the use of certain radioactive materials must be closely regulated to protect the health and safety of the public and the environment. Toward that end, the responsibility for licensing and regulating the use and handling of these materials is shared by the following governmental organizations: The U.S. Environmental Protection Agency - Among other things, the EPA is responsible for setting air emission and drinking water standards for radioisotopes, which are an unstable isotope of an element that decays or disintegrates spontaneously, thereby emitting radiation. Approximately 5,000 natural and artificial radioisotopes have been identified. The Food and Drug Administration - The FDA regulates the manufacture and use of specialized devices (known as linear accelerators) that are used to create radioisotopes for use in some nuclear medicine procedures. Nuclear medicine is the use of radioactive materials in diagnostic or therapeutic procedures, most notably treatments for various forms of cancer. The U.S. Nuclear Regulatory Commission (NRC) and its Agreement States license and regulate the possession and use of radioactive materials for nuclear medicine. However, the NRC and its Agreement States do not practice medicine and do not give medical advice. However, the States regulate the operation of such devices. The U.S. Nuclear Regulatory Commision - The NRC is the Federal agency responsible for protecting the health and safety of the public and the environment by licensing and regulating the civilian uses of the following radioactive materials: Source material (uranium and thorium) Special nuclear material (enriched uranium and plutonium) Byproduct material (material that is made radioactive in a reactor, and residue from the milling of uranium and thorium) The NRC regulates the use of these radioactive materials through Title 10, Part 20, of the Code of Federal Regulations (10 CFR Part 20), Standards for Protection Against Radiation, which spells out the agency s requirements for the following aspects of radiation protection: Dose limits for radiation workers and members of the public Exposure limits for individual radionuclides Monitoring and labeling radioactive materials Posting signs in and around radiation areas Reporting the theft or loss of radioactive material Penalties for not complying with NRC regulations Of more than 20,000 active source, byproduct, and special nuclear materials licenses in place in the United States, about a quarter are administered by the NRC, while the rest are administered by 37 Agreement States. 3

4 Welcome to RADtown USA! - The Countryside Each day, we are exposed to radiation from various sources, regardless of where we live or our fields of work. RADtown USA explains radiation in our towns, and how it is used. Explore these sources of radiation in The Burbs, Downtown, Countryside, or Waterfront. In this issue of the RAD Safety Newsletter, we ll explore The Countryside. Radioactive material can be produced during fertilizer production. An ingredient in some fertilizers is the mineral phosphorous. The most common method for making fertilizer containing phosphorous leaves behind a waste called phosphogypsum. Phosphogypsum emits radon, a radioactive gas. It also contains uranium and radium, which are radioactive elements. Phosphogypsum is stored in big piles called stacks. As the phosphogypsum dries out, it forms a thick crust that keeps the radon from escaping into the air. Uranium Mines and Mills: Uranium is used as nuclear fuel for electric power generation. U.S. mining industries can obtain uranium in two ways: mining or milling. Mining waste and mill tailings can contaminate water, soil and air if not disposed of properly. Industrial Radiography: Manufacturers use a method called industrial radiography to check for cracks or flaws in materials. Radiation is used in industrial radiography to show problems not visible from the outside without damaging the material. Workers who use industrial radiography equipment must be trained to use it and wear special badges that measure their exposure to radiation. Exposure of the public to radiation from industrial radiography equipment is not likely, because the public is not permitted in areas where testing is conducted. Nuclear Gauges are used in road construction. Nuclear gauges use radioactive sources to measure the thickness, density or make-up of a wide variety of materials and surfaces. When properly used, nuclear gauges will not expose the public to radiation. Natural Radiation occurs in wastes from Coal-Fired Power Plants. Fly ash, bottom ash and boiler slag from coal-fired power plants contain small amounts of naturally occurring radioactive material. In 2012, approximately 37 percent of the United States electricity was created by burning coal. Like all rocks, coal contains small amounts of radioactive material that are found naturally in the environment. When coal burns, most of the radioactive material does not burn and ends up in three types of wastes, so naturally radioactive materials that were in coal before processing mostly end up in fly ash, bottom ash and boiler slag. About 80 to 90 percent of fly ash, bottom ash and boiler slag is non-radioactive minerals, typically silicon, aluminum, iron and calcium. 4

5 Over half of the average annual radiation exposure of people in the U.S. comes from natural sources. In the outdoors, solar activity and sun exposure can be a source of radiation. Radionuclides can occur naturally, or can be man-made in our ecosystems. Often times, radionuclides can be found in private wells. They should test for radionuclides every three years and take appropriate steps if radionuclide levels are higher than EPA s limits. Radioactive elements are part of our ecosystem, part of the air we breathe, the water we drink and the food we eat. Radioactive Fallout From Nuclear Weapons Testing: Detonating nuclear weapons above ground sends radioactive materials into the atmosphere from the ground level up to very high elevations. Fallout typically contains hundreds of different radionuclides. Since the end of aboveground nuclear weapons testing, radionuclides have largely decayed away. Radioactive Material in Scrap Metal: Sometimes radioactive materials are disposed of improperly and end up in scrap metal yards. You will probably never come into contact with contaminated scrap metal. If you think you have found contaminated scrap metal, do not touch it. Immediately contact your state radiation office. Sometimes radioactive materials are disposed of improperly and end up in scrap metal yards. There are several types of radioactive materials that can end up in scrap metal yards. For example, some industrial devices contain a small quantity of safely enclosed radioactive material called a sealed source. Found or abandoned radioactive sources are called orphan sources when their identifying marks have been removed or damaged. Orphan sources do not have owners to dispose of them properly. Stay tuned for the Spring Newsletter, where we ll visit RADtown s WATERFRONT! Laboratory and Radiation Safety There for you, at your service Who you gonna call? Radiation Safety Contacts Name Office Cell OUPD Alan Watts Ricardo Gaytan David Schleter David Ingram