Nuclear disaster

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Nuclear disaster is a human-caused catastrophe, characterised in that, that the significant (and dangerous) amount of unstable isotopes is released into atmosphere, water, ground.

The most known nuclear disasters are the

  1. 1957.09.29.Mayak disaster
  2. Chernobyl disaster
  3. Fukushima disaster

Application of a nuclear weapon or its testing also can be considered as a nuclear disaster.

Chernobyl disaster

At the Chernobyl disaster, estimates of amount of the most important contaminants released are suggested by Aleksandr Borovoi [1]:

$ \begin{array}{ccccrrt} \rm Isotope & \rm mode & T_{1/2},~\rm y & \rm mass,\, kg & \rm activity,\, Ci \!\!\!\! \\ \rm ^{238}Pu & \alpha & 86 & ~1.5\!\!\!\!\! & 2.5\!\times\! 10^4 \\ \rm ^{239}Pu & \alpha & 2.4\!\times\! 10^4&\!\!420 & 2.6\!\times\! 10^4 \\ \rm ^{240}Pu & \alpha & 6.5\!\times\! 10^3&\!\!175 & 4\!\times\! 10^4\\ \rm ^{241}Pu & \beta & 14 &50 & 5\!\times\! 10^5\\ \rm ^{137}Cs &\beta,\gamma& 30 &81 & 7\!\times\! 10^6\\ \rm ^{90}Sr &\beta & 29 &43 & 6\!\times\! 10^6\\ \end{array} $

The most important contaminants seems to be Pu-238, Pu-239, Pu-240, Pu-241 (that in, roughly, 14 years gradually converts to the even more dangerous Am-237), Cs-137 (that emits not only $\beta$ rays, but $\gamma$ rays too), Sr-90 (that chemically behaves as Calcium and tends to accumulate in bones)

The short–living isotopes of Iodine are dangerous only within first weeks since the disaster; as for Radon, it does not accumulate in a human bogy.

Also, usually, one does( not consider as serious contaminant isotopes of Uranium: U-232 (due to its low concentration in the pollution), U-233, U-235, U-239 due to their long halftime (longer than $10^5$ years).

However, the concentration of U-232 is expected to be high at the destruction of equipment that uses thorium as fuel (through the U-233).

References

  1. http://scepsis.net/library/id_711.html Александр Боровой. Внутри и вне Саркофага. «Природа», №11, 1990 год.

Keywords

1957.09.29.Mayak disaster [[]], Chernobyl disaster, Fukushima disaster, Nuclear disaster, [[]],,,,,