The World of Norm Collection 10 Books Box Set (Book 1-10) By Jonathan Meres

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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. 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 NORM The first four columns represent four of the 14 nuclides in the uranium decay series, the next two represent two of 10 in the thorium series. (For total activity in any coal, assume these are in serial equilibrium, hence multiply U-238 by 14 and Th-232 by 10, then add K-40.) NORM in the oil and gas industry poses a problem to workers particularly during maintenance, waste transport and processing, and decommissioning. In particular Pb-210 deposits and films, as a beta emitter, is only a concern when pipe internals become exposed. External exposure due to NORM in the oil and gas industry are generally low enough not to require protective measures to ensure that workers stay beneath their annual dose limits (such as set out by the IAEA basic safety standards). Internal exposures can be minimized by hygiene practices. Metals and smelting The amounts of radionuclides involved are noteworthy. US, Australian, Indian and UK coals contain up to about 4 ppm uranium, those in Germany up to 13 ppm, and those from Brazil and China range up to 20 ppm uranium. Thorium concentrations are often about three times those of uranium.

Over 95% of the market for zirconium requires it in the form of zircon (zirconium silicate). This mineral occurs naturally and is mined, requiring little processing. It is used chiefly in foundries, refractories manufacture and the ceramics industry. Zircons typically have activities of up to 10,000 Bg/kg of U-238 and Th-232. No attempt is usually made to remove radionuclides from the zircon as this is not economical. Because zircon is used directly in the manufacture of refractory materials and glazes, the products will contain similar amounts of radioactivity. Higher concentrations may be found in zirconia (zirconium oxide), which is produced by high temperature fusion of zircon to separate the silica. Zirconium metal manufacture involves a chlorination process to convert the oxide to zirconium chloride, which is then reduced to the metal.Radioactive materials which occur naturally and where human activities increase the exposure of people to ionising radiation are known by the acronym 'NORM'. Gabbard, A. 1993, Coal Combustion: Nuclear Resource or Danger?, Oak Ridge National Laboratory Review, Vol. 26, Nos. 3&4 Long-lived radioactive elements such as uranium, thorium and potassium and any of their decay products, such as radium and radon are examples of NORM. These elements have always been present in the Earth's crust and atmosphere, and are concentrated in some places, such as uranium orebodies which may be mined. The term NORM exists also to distinguish ‘natural radioactive material’ from anthropogenic sources of radioactive material, such as those produced by nuclear power and used in nuclear medicine, where incidentally the radioactive properties of a material maybe what make it useful. However from the perspective of radiation doses to people, such a distinction is completely arbitrary. Mineral sands contain zircon, ilmenite, and rutile, with xenotime and monazite. These minerals are mined in many countries and production amounts to millions of tonnes per year of zirconium and titanium (from rutile and ilmenite), though thorium, tin and the rare earth elements are associated. The NORM aspect is due to monazite – a rare earth phosphate containing a variety of rare earth minerals (particularly cerium and lanthanum) and 5-12% (typically about 7%) thorium, and xenotime – yttrium phosphate with traces of uranium and thorium.

Earlier IAEA recommendations for the classification of exempt waste ( i.e. beneath low-level, and therefore not requiring any special facilities for disposal) are between 10 Bq/g and 1 MBq/g for 'moderate amounts'– depending on the radionuclide in question and the chances of public exposure ( Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, IAEA July 2014), however in practice categorization of waste is strongly determined by where the waste comes from. The list of isotopes that contribute to natural radiation can be divided into those materials which come from the ground (terrestrial sources – the vast majority) and those which are produced as a result of the interaction of atmospheric gases with cosmic rays (cosmogenic). Excluding uranium mining and all associated fuel cycle activities, industries known to have NORM issues include: Over the years there have been many occasions when it was asserted that coal-fired power stations emitted more radioactivity into the environment (from NORM) than was released anywhere in the nuclear fuel cycle. While having some basis in fact, the claim is generally not correct now where deployment of emission reduction technology– scrubbers, filters and flue gas desulphurization– acts to capture solids from this material.More volatile Po-210 and Pb-210 still escape. In China, coal-fired power plants are a major source of radioactivity released to the environment and thus contribute significantly to enhanced NORM there. (Wu et al in NORM VII) During combustion the radionuclides are retained and concentrated in the flyash and bottom ash, with a greater concentration to be found in the flyash. The concentration of uranium and thorium in bottom and flyash can be up to ten times greater than for the burnt coal, while other radionuclides such as Pb-210 and K-40 can concentrate to an even greater degree in the flyash. Some 99% of flyash is typically retained in a modern power station (90% in some older ones). While much flyash is buried in an ash dam, a lot is used in building construction. Table 3 gives some published figures for the radioactivity of ash. There are obvious implications for the use of flyash in concrete.International Atomic Energy Agency, Naturally Occurring Radioactive Material (NORM VII): Proceedings of an International Symposium Beijing, China, 22-26 April 2013, STI/PUB/1664, ISBN 9789201040145 (January 2015) Radon in homes is one occurrence of NORM which may give rise to concern and action to control it, by ventilation. In Australia the NSW Aboriginal Lands Council has applied for a uranium exploration licence over four large coal ash dams adjacent to power stations. Coal mining