Geiger Counters 6 - Annual Average Radiation Dose

In order to accurately measure radiation with a Geiger counter, we must start with the normal background radiation. Background radiation comes from both natural and man-made radioactivity. Previous posts have detailed various sources from both of these types. The actual regular background radiation varies from place to place on the surface of the Earth. It also varies with time depending on the weather, the seasons and human activities.

Geiger Counters 4 - Features

                There are a number of considerations that should be taken into account when purchasing a Geiger counter. Increased public concerns about radiation exposure, especially since Fukushima, have resulted in an explosion of inexpensive hand-held Geiger counters being brought onto the market. There are many manufacturers and models. If you going to buy a Geiger counter, here is a list of things to watch out for.

Geiger Counters 3 - Uses

            Geiger counters have many important uses with respect to the detection and measurement of alpha, beta and gamma radiation. Uranium-238 with traces of  uranium-235 is mined for refinement use as a fuel. Plutoium-239 and thorium-232 are also used as nuclear fuels. The use of commercial radioisotopes is wide-spread. Sources of alpha particles or helium nuclei include polonium-210 and uranium-238. Sources of beta particles or fast electrons include strontium-90, thallium-204, carbon-14 and hydrogen-3 or tritium. Sources of energetic photons of gamma include barium-133, cadmium-109, cobalt-57, cobalt-60, europium-152, manganese-54, sodium-22, zinc-65 and technetium-99. Cesium-137 emits gamma and beta. Americium-241emits gamma and alpha.

Non-nuclear Industrial Uses

            Radiation and Geiger counters are used to measure the strength of welds, the wear and corrosion of metals, and in the analysis of minerals and fuels. Gamma rays from Cobalt-60 are used to kill bacteria in foods and halt cellular processes that would lead to sprouting. This process must be closely monitored.

Nuclear Industry Uses

            Geiger counters are used for detecting leakage of radioactive materials from containers during storage and transportation, detecting radioactive contamination of other objects and materials, detecting leakage of radiation from pipes and containment vessels in nuclear power plants. Geiger counters are used to locate and evaluate deposits of uranium ores.

Environmental Uses

            Geiger counters are used to monitor radiation levels in the atmosphere, ground water, lakes, rivers and oceans. Radiation is monitored in landfills and dumps, nuclear waste repositories, warehouses and transport areas. Radioisotopes can help monitor pollutants and to measure the movement of surface waters as well as the runoff of rain water. Geiger counters are used by first responders to check for radiation at a disaster site or the site of a terrorist attack.

Home Uses

            Radon gas is a significant danger in homes and should be monitored. Smoke detectors contain radioactive materials that may be released if the detectors are damaged. Radioactive particles and gases may invade the home from nuclear accidents and can be tested for with Geiger counters.

Medical Uses

            A number of different isotopes are utilized in modern medicine that must be carefully handled and should be monitored by Geiger counters. Some medical equipment emits radiation such as X-rays. Radioisotopes injected into patients are taken up by specific tissues and used for imaging or for treatment of cancers.

Laboratory Uses

Geiger Counters 2 - Evolution of common Geiger Counters

            Ionizing radiation is measured by a device called a Geiger counter. The Geiger counter is named after its inventor Hans Geiger who created the Geiger counter in 1908. Walther Müller collaborated on improving the counter in 1928 and the counters are also called Geiger-Müeller counters.  A Geiger counter consists of a Geiger-Müeller tube which detects radiation by emitting a pulse of electrical energy when penetrated by ionizing radiation and supporting hardware.

            Geiger-Mueller tubes come in a range of sizes, shapes and sensitivities. One end is open to allow the entry of ionizing radiation. Some Geiger counters allow thin shields which block alpha particles and thick shields which block beta particles to be shifted into position over the open end of the tube. The tube may be included inside a handheld device or it may be on a cable attached to a box containing the support hardware. Inexpensive Geiger counters for wide spread use have evolved over the years.

            The US federal civil defense agencies had a Geiger counter design called a CD V-700 manufactured by 15 different contractors beginning around 1950.. The early models used special high voltage batteries which were replaced by standard D cells in the later models. CD V-700 design included  bulky metal box about twelve inches long by eight inches high by six inches wide and weighting about 5 pounds. The box has a long handle running the length of the top. The Geiger-Müeller tube is about nine inches long and three inches in diameter on a thirty six inch cable. The CD V-700 is used to detect gamma and beta radiation. Some were modified to be able to detect alpha radiation by making the window in the end of the tube larger to provide more area. Tens of thousands of these models were distributed to build state and local civil defense agencies in the 1950s and 1960s These Geiger counters are what people usual think of when Geiger counters are mentioned. They have been featured in many movies and television shows and many are still in use today.

            A newer design was manufactured for the U.S. government in the 1980s by the Victoreen company, one of the contractors for the original CD V-700. The model 496 was build in the same box as the CD V-700 but featured some improvements such as BNC connectors for external probes, a built in speaker that clicks to indicate radiation, a batter test circuit and a meter graduated in clicks per minute.

Nuclear Institutions 6 - Nuclear Energy Agency

            In 1958, the European Nuclear Energy Agency (ENEA) was formed as a special agency within the Organization for Economic Co-operation and Development with the United States as an associate member. With the entry of Japan in 1972, the name was changed to the Nuclear Energy Agency.

            The mission of the NEA is to "assist its Member countries in maintaining and further developing, through international co-operation, the scientific, technological and legal bases required for the safe, environmentally friendly and economical use of nuclear energy for peaceful purposes."

            There are thirty member counties including Australia, Austria, Belgium, Canada, the Czech  Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Luxembourg, Mexico, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, Turkey, the United Kingdom and the United States.

            The NEA deals with nuclear safety and regulation, nuclear energy development, radioactive waste management, radiation protection and public health, nuclear law and liability, nuclear science, nuclear information and communication. NEA members host about eighty five percent of the nuclear generating capacity of the world. Almost a fourth of the electricity produced in the member nations is generated by nuclear reactors.

            The NEA utilizes a relatively small staff to coordinate technical committees charged with carrying out the seven primary functions of the Agency. The committees are composed of technical experts from the member nations. The committees foster discussions, technical exchanges, cooperative research programs, consensus building and cost reduction in nuclear research. The NEA has made major contributions to nuclear waste disposal and reactor technology development during the past 30 years.

            The NEA just released its strategic plan for 2011-2016. The three main topics or concern are supplying the increasing world demand for energy, insuring the security of the energy supply and minimizing impacts on the environment.  The document emphasizes that the current trends in energy supply and use are unsustainable with increasing demands, reliance on fossil fuels, competition for natural gas and oil deposits, increasing CO2 levels and severe environmental impacts. The plan calls for increased use of nuclear power because of it releases no CO2 or other pollutants and it is currently cost competitive with coal, oil and natural gas. The challenge for greater acceptance of nuclear power lie in finding solutions to the long term management of spent nuclear fuel, the safe and permanent disposal of radioactive waste, the security of nuclear materials and facilities and the insurance of non-proliferation of nuclear weapons.

Nuclear Institutions 5 - Japanese Nuclear Agencies

Japan Nuclear Cycle Development Institute

            The JNC was established in 1956 as the Atomic Fuel Corporation (AFC). The AFC became the Power Reactor and Nuclear Fuel Development Cooperation (PNC) in 1967. The PNC became the JNC in 1998. The mission of the incarnations of the JNC was involved with researching, developing and monitoring the nuclear fuel cycle in Japan.

Japan Atomic Energy Research Institute

            The JAERI was established in 1956. It's job was to encourage and oversee research on application of nuclear materials and nuclear energy for Japan.

Japan Atomic Energy Agency

            The Japan Atomic Energy Agency (JAEA) was formed in 2005 by the Japan Atomic Energy Agency Act of 2005. It was created by the merger of two existing agencies, the Japan Nuclear Cycle Development Institute (JNC) and the Japan Atomic Energy Research Institute (JAERI).

            The scope of the JAEA mission includes basic and application nuclear research, technical evolution of the nuclear fuel cycle, facility sharing, human resource development for the nuclear industry, collection and dissemination of nuclear information, safety regulation, nuclear disaster prevention and response, environmental monitoring, international non-proliferation, and decommissioning and disposal of nuclear waste.  There are four major divisions of the JAEA including a Management Sector, R&D directorates, R&D Institutes/centers and a Project Promotion Sector.

            The JAEA came under intense scrutiny and criticism for its response (or lack of response) to the Fukushima nuclear disaster. Part of the problem was the clumsy, biased and incompetent job the JAEA did in communicating with the Japanese public during and after the disaster.

Japanese Atomic Energy Commission

            The Japanese Atomic Energy Commission (JAEC) was created in 1956. It is the primary nuclear regulatory agency for nuclear energy and materials in Japan. Its mission is to plan, consider and decide on policies for the promotion of research, development and utilization of nuclear energy. The JAEC also advises the government on the organization and budgeting of nuclear agencies in Japan.

Japanese Nuclear Safety Commission

            The Japanese Nuclear Safety Commission (NSC) was spun off from the Japanese Atomic Energy Commission in 1978. It is included in the Cabinet of the Japanese Prime Minister and is charged with advising the Prime Minister on matters of nuclear safety.

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