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Naturally occurring strontium is nonradioactive and nontoxic at levels normally found in the environment, but 90 Sr is a radiation hazard. [4] 90 Sr undergoes β − decay with a half-life of 28.79 years and a decay energy of 0.546 MeV distributed to an electron, an antineutrino, and the yttrium isotope 90 Y, which in turn undergoes β − decay with a half-life of 64 hours and a decay energy ...
Specific activity (symbol a) is the activity per unit mass of a radionuclide and is a physical property of that radionuclide. [ 1 ] [ 2 ] It is usually given in units of becquerel per kilogram (Bq/kg), but another commonly used unit of specific activity is the curie per gram (Ci/g).
The mean strontium content of ocean water is 8 mg/L. [50] [51] At a concentration between 82 and 90 μmol/L of strontium, the concentration is considerably lower than the calcium concentration, which is normally between 9.6 and 11.6 mmol/L. [52] [53] It is nevertheless much higher than that of barium, 13 μg/L. [11]
Strontium-90 has a shorter half-life, produces less power, and requires more shielding than plutonium-238, but is cheaper as it is a fission product and is present in a high concentration in nuclear waste and can be relatively easily chemically extracted. Strontium-90 based RTGs have been used to power remote lighthouses. [1]
strontium-90: 28.79 909 curium-243: 29.1 920 caesium-137: 30.17 952 10 9 seconds (gigaseconds) isotope half-life years 10 9 seconds bismuth-207: 32.9 1.04 titanium-44: 63
But 90 Sr has a 30-year half-life, and 89 Sr a 50.5-day half-life. Thus in the 50.5 days it takes half the 89 Sr atoms to decay, emitting the same number of beta particles as there were decays, less than 0.4% of the 90 Sr atoms have decayed, emitting only 0.4% of the betas. The radioactive emission rate is highest for the shortest lived ...
However, specific means of this migration still remain unknown. [11] The researchers forecast that in case of inviolated protection of nuclear waste dumps in exclusion zone, the concentration of Strontium-90 up to 2020 will be much lower in subsurface water than admissible maximum indexes.
Yttrium-90 is produced by the nuclear decay of strontium-90 which has a half-life of nearly 29 years and is a fission product of uranium used in nuclear reactors. As the strontium-90 decays, chemical high-purity separation is used to isolate the yttrium-90 before precipitation .