Strontium neutron absorption

Nixon277 compared atomic absorption spectroscopy, flame photometry, mass spectroscopy, and neutron activation analysis as methods for the determination of some 21 trace elements (<100 ppm) in hard dental tissue and dental plaque silver, aluminum, arsenic, gold, barium, chromium, copper, fluoride, iron, lithium, manganese, molybdenum, nickel, lead, rubidium, antimony, selenium, tin, strontium, vanadium, and zinc. Brunelle 278) also described procedures for the determination of about 20 elements in soil using a combination of atomic absorption spectroscopy and neutron activation analysis. 

The present method of analysis offers several distinct advantages. The first of these is speed calcium, barium, and strontium concentrations are determined simultaneously in a short irradiation, and analysis of up to seven samples can be completed within hours. Neutron activation analysis is highly sensitive to the elements of interest compared with other methods such as x-ray fluorescence and atomic absorption techniques. Additionally, the required sample size is small (10-20 mg), thus resulting in little alteration of archaeological specimens. 

GPC (total radioactive strontium) = beta gas proportional counter Bq = Becquerel dpm = disintegrations per minute EDTA = ethylenediamine tetraacetic acid GFAAS (total strontium) = graphite furnace atomic absorption spectroscopy ICP-AES (total strontium) = inductively coupled plasma atomic emission spectroscopy ICP-MS (isotopic strontium composition) = inductively coupled plasma-mass spectrometry LSC (isotopic quanitification of 89Srand 90Sr) = liquid scintillation counting pCi = pico curies (10-12 curies) PIXE (total strontium) = proton induced x-ray emission TMAH = tetramethylammonium hydroxide TNA (total strontium) = thermal neutron activation and radiometric measurement TRXF (total strontium) = total-reflection x-ray fluorescence... 

Despite the absence of any known biological roles for strontium, analysis of trace amounts of the alkali earth metal in many environmental and industrial samples and, especially, in radioactive waste is of critical importance. Techniques applicable for analyzing strontium in environmental or biological material are atomic absorption spectrometry (AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES), direct-current plasma echelle spectrometry, neutron activation analysis and X-ray fluorescence. For most applications, the first two mentioned methods are of interest because, in general, they allow... 

Storage of spent nuclear fuel poses a major problem because the fission products are extremely radioactive. It is estimated that 20 half-lives are required for their radioactivity to reach levels acceptable for biological exposure. Based on the 28.8-yr half-life of strontium-90, one of the longer-lived and most dangerous of the products, the wastes must be stored for 600 years. Plutonium-239 is one of the by-products present in spent fuel elements. It is formed by absorption of a neutron by uranium-238, followed by two successive beta emissions. (Remember that most of the uranium in the fuel elements is uranium-238.) If the elements are reprocessed, the plutonium-239 is largely recovered because it can be used as a nuclear fiieL However, if the plutonium is not removed, spent elements must be stored for a very long time because plutonium-239 has a half-life of24,000 yr. 

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