Potassium isotopes concentration

As a potential disadvantage of KOH-NH3 chemistry, the production of additional radionuclides in the primary coolant has to be mentioned. Thus, by an (n,p) reaction with considerable amounts of are generated. Several radionuclides are produced by neutron capture in the different potassium isotopes, the most important of them being (halflife 12.5 hours), which is a p emitter with an associated y energy of 1.5 MeV. During operation at rated power with a potassium concentration in the primary coolant of about 10 ppm, a steady-state activity concentration on the order of 10 to 50 GBq/Mg is produced. Due to its short halflife, this radionuclide does not pose any problems in refuelling operations likewise, because of its high solubility in water it does not form deposits on the... 

Crystallisation was one of the earliest methods used for separation of radioactive microcomponents from a mass of inert material. Uranium X, a thorium isotope, is readily concentrated in good yield in the mother liquors of crystallisation of uranyl nitrate (11), (33), (108). A similar method has been used to separate sulphur-35 [produced by the (n, p) reaction on chlorine-35] from pile irradiated sodium ot potassium chloride (54), (133). Advantage is taken of the low solubility of the target materials in concentrated ice-cold hydrochloric acid, when the sulphur-35 as sulphate remains in the mother-liquors. Subsequent purification of the sulphur-35 from small amounts of phosphorus-32 produced by the (n, a) reaction on the chlorine is, of course, required. Other examples are the precipitation of barium chloride containing barium-1 from concentrated hydrochloric acid solution, leaving the daughter product, carrier-free caesium-131, in solution (21) and a similar separation of calcium-45 from added barium carrier has been used (60). 

For both cesium and barium sorption, there is reasonable agreement between the total concentrations of desorbed species and the ion-exchange capacities determined by isotopic redistribution. The small differences which exist could easily be due to the precision in the elemental analyses. (Also, the experimental technique would not have detected desorption of hydrogen ions.) The solid-phase concentrations of sodium, potassium, magnesium, calcium. 

Iindau and Spalding [21] have studied the effects of 2 M potassium chloride extractant ratios of between 1 1 to 1 10 on nitrate recovery in nitrate and nitrite extractions from soil. Preliminary data indicated that concentrations of extractable nitrate and nitrogen isotopic values were influenced by the volume of extractant. The 1 1 extractions showed decreasing nitrogen isotope values with increasing nitrate levels, whereas in the 1 10 extractions these values were independent of each other. Incomplete extraction occurred for the 1 1 ratios. The ratio required for maximal recovery was not determined. 

The EPA developed two methods for the radiochemical analysis of uranium in soils, vegetation, ores, and biota, using the equipment described above. The first is a fusion method in which the sample is ashed, the silica volatilized, the sample fused with potassium fluoride and pyrosulphate, a tracer is added, and the uranium extracted with triisooctylamine, purified on an anion exchange column, coprecipitated with lanthanum, filtered, and prepared in a planchet. Individual uranium isotopes are separately quantified by high resolution alpha spectroscopy and the sample concentration calculated using the yield. The second is a nonfusion method in which the sample is ashed, the siUca volatilized, a tracer added, and the uranium extracted with triisooctylamine, stripped with nitric acid, co-precipitated with lanthanum, transferred to a planchet, and analyzed in the same way by high resolution a-spectroscopy (EPA 1984). 

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