May Contain Nuts: Book 1 (The World of Norm)
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Activity concentration guidelines for the use of NORM residues in building construction have been developed using the ACI approach and material has been classified into three categories, depending on whether the dose is below 0.5 mSv/yr (unrestricted use), between 0.5 and 1 mSv/yr (use restricted to roads, bridges, dams or, with dilution, low occupancy buildings) or above 1 mSv/yr (prohibited use). These levels correspond to equivalent activity concentration under 350 Bq/kg (and under 200 Bq/kg Ra-226), 350 to 1350 Bq/kg (200-1000 Bq/kg Ra-226) and over 1350 Bq/kg (1000 for Ra-226) respectively.
Home alone and the fridge to himself? What could possibly go wrong? Well, apart from the snails. And having to hang his mum’s pants out to dry. And the dreaded perfect cousins paying a visit. And worst of all, the entire family going vege-flipping-tarian! But apart from that, what could possibly go wrong? Cooper, M. B. 2005 Naturally Occurring Radioactive Materials (NORM) in Australian Industries - Review of Current Inventories and Future Generation, ERS-006, A Report prepared for the Radiation Health and Safety Advisory Council NORM levels are typically expressed in one of two ways: Becquerels per kilogram (or gram) indicates level of radioactivity generally or due to a particular isotope, while parts per million (ppm) indicates the concentration of a specific radioisotope in the material. Terrestrial NORMCosmogenic NORM is formed as a result of interactions between certain gases in the Earth’s atmosphere and cosmic rays, and is only relevant to this paper due to flying being a common mode of transport. Since most cosmic radiation is deflected by the Earth’s magnetic field or absorbed by the atmosphere, very little reaches the Earth’s surface and cosmogenic radionuclides contribute more to dose at low altitudes than cosmic rays as such. At higher altitudes, the dose due to both increases, meaning that mountain dwellers and frequent flyers are exposed to higher doses than others. For most people, cosmogenic NORM barely contributes to dose – perhaps a few tens of microsieverts per year. By contrast, terrestrial NORM – especially radon – contributes to the majority of natural dose, usually over 1000 microsieverts (1 mSv) per year. Some of the main comsogenic nuclides are shown in Table 1, carbon-14 being important for dating early human activities. International Atomic Energy Agency, 2014, Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, STI/PUB/1578 (July 2014) European Commission (Directorate-General Environment, Radiation Protection) 2003, Radiation protection 132: MARINA II, Update of the MARINA Project on the radiological exposure of the European Community from radioactivity in North European marine waters
Access-restricted-item true Addeddate 2018-12-12 23:42:06 Boxid IA1512322 Camera Sony Alpha-A6300 (Control) Collection_set china External-identifier urn:lcp:worldofnormmayco0000mere:epub:5699639c-dbc5-4e03-84a6-baf2b08e4ae3 Foldoutcount 0 Identifier worldofnormmayco0000mere Identifier-ark ark:/13960/t14n6m19c Invoice 1213 Isbn 9781408313039The EU encourages the use of NORM residues in building materials, subject to dose rate from gamma exposure being below 1 mSv/yr from them. Coal ash and smelting slag are an important constituent of building materials in China. Recycling and NORM
International Atomic Energy Agency, Extent of Environmental Contamination by Naturally Occurring Radioactive Material (NORM) and Technological Options for Mitigation, Technical Reports Series No. 419, STI/DOC/010/419, ISBN: 9201125038 (December 2003)
Typically exposure to radon and its progeny accounts for half of an individual’s radiation dose, making it the single largest contributor. This radon comes from the ground, with exposure affected by factors such as local geography, building construction, and lifestyle. Radon levels in the air range from about 4 to 20 Bq/m 3. Indoor radon levels have attracted a lot of interest since the 1970s and in USA they average about 55 Bq/m 3, with an EPA action level of 150 Bq/m3. Levels in Scandinavian homes are about double the US average, and those in Australian homes average one fifth of those in USA. Levels up to 100,000 Bq/m 3 have been measured in US homes. In caves open to the public, levels of up to 25,000 Bq/m 3 have been measured.A Japanese study on 3000 residents living in an area with 60 Bq/m 3 radon near Misasa hot springs showed no health difference. The ICRP recommends keeping workplace radon levels below 300 Bq/m 3, equivalent to about 10 mSv/yr. Eisenbud, M.; and Gesell, T. F. 1997, Environmental Radioactivity from Natural, Industrial & Military Sources, Fourth Edition: From Natural, Industrial and Military Sources, Academic Press (ISBN: 9780122351549)