The Chernobyl (Ukraine, 1986) and the Fukushima (Japan, 2011)
accidents have been rated on the International Atomic Energy Agency (IAEA)
International Nuclear and Radiological Event Scale (INES) as a “Major Accident”
as INES 7.
The Chernobyl nuclear disaster struck on 26 April 1986 during a
routine technological investigation in Unit 4 of the Nuclear Power Plant (Steinhauser, G., Brandl, A., & Johnson, T. E.,
2014). Malfunctioning of the reactor in the
operation resulted in the “xenon-poisoning” which the reactor staff failed
to point out, thereby causing inappropriate operation of the control rod in the reactor (Grishanin, 2010). According to (Michel, R.,
Voigt, G., 2006)
the sudden power outing which was
occasioned by operating error led to the destruction of the RBMK-1000 reactor
which at the end caused some blast-off of the graphite moderators.
The Fukushima
nuclear disaster occurred in March 2011.
It was caused by the earth quake that hit Japan. The tsunami, went as high as
14m at the plant site. Of the six reactors, three (Units 1, 2, and 3) were running, at the time
of the earthquake, but the first seismic signals of the
earthquake triggered an automatic shutdown of these reactors.
The so called “safe zone” was a thirty kilometer radius around the nuclear power plant. About 116000 people within the “safe zone” were estimated to have
been evacuated to area that was not
heavily polluted few months after the accident.
After the disaster rescue of people started from 3–11 days , which for some
of the affected persons, it was already late (Prohl, G., Muck, K., Likhtarev, I., Kovgan, L., Golikov, V., 2002). The safe zone was
extended and covered 4300 km2 in 1996, so as
to control the areas with the maximum radiation levels (Steinhauser, G., Brandl, A., & Johnson, T. E.,
2014).
In the
Fukushima accident, over 80% of the atmospherically-released radionuclide were
anticipated to have gone offshore
followed by deposition in the Pacific Ocean (Kawamura, H., Kobayashi, T., Furuno, A., In, T., Ishikawa, Y., Nakayama,
T., … & Awaji, T., 2011). According to (Buesseler,
K. O., Jayne, S. R., Fisher, N. S., Rypina, I. I., Baumann, H., Baumann, Z.,
… & Miyamoto, H., 2012; Madigan, D. J., Baumann, Z., & Fisher, N.
S., 2012)
radionuclide from Fukushima were found in seawater and marine organisms
throughout the Pacific.
According to (Behrens, E., Schwarzkopf, F. U.,
Lübbecke, J. F., & Böning, C. W., 2012) the impact from the radionuclide in
other countries apart from Japan seem
minima, because the ocean was quick to
neutralize it.
There was high contamination outside the safe zone because Chernobyl is in the
heart of Europe (Steinhauser, G., Brandl, A., & Johnson, T. E., 2014).
