Environmental Engineering Reference
In-Depth Information
for twenty-two minutes when backup generators failed to fi re during a
power cut. When such a failure occurs, the operator loses instrumenta-
tion and control over the reactor, leading to an inability to cool the core.
Failures such as this have also been reported in the United States and
Germany. Core meltdown was narrowly averted when an engineer dis-
obeyed rules and overruled safety systems to source power from other
parts of the facility.
Reactors in Japan
There have been more than 12,000 cumulative reactor-years of opera-
tions worldwide since the 1950s with only two major events resulting
from human error—one in the United States in 1979, the other in
Ukraine in 1986. Both were widely publicized. Less publicized was the
event in 1999 at Tokaimura, Japan, a town 75 miles from downtown
Tokyo. Workers accidentally mixed together enough uranium-235 to
trigger a runaway chain reaction that burned uncontrolled for twenty
hours. The accident unleashed radiation 20,000 times the normal level
and injured at least forty-nine people, some critically. Local people were
exposed to radiation levels estimated to be one hundred times the annual
safe limit. Radioactive rain fell in the surrounding area. Investigators
subsequently found higher-than-expected uranium concentrations in the
environment around the reactor site, possibly indicating prior unreported
accidents.
Japan should be particularly concerned about nuclear power plants.
The land area of the Japanese archipelago is the size of Montana, has
fi fty-fi ve reactors, and is located in an area where several continental and
oceanic plates meet. This is the cause of the many earthquakes that rock
the islands. There have been ten with magnitudes between 6.6 and 7.9
since 2004. The most recent major one was a 6.5 magnitude quake in
July 2009 that created some fi fty problems at a large nuclear plant. In
addition, the tremors tipped over several hundred barrels of radioactive
waste, opening the lids on dozens of the barrels. And 317 gallons of
radioactive water fl owed into the Sea of Japan. Japanese nuclear power
plants are disasters waiting to happen. Building nuclear reactors in Japan
is about the same as scattering bread crumbs for fl ea-infected rats to eat
during the fourteenth-century bubonic plague in Europe.
The inspection system in Japanese nuclear plants is lax, and there is
a culture of secrecy. For the most part, the nuclear power companies are
expected to monitor themselves. Perhaps a bigger problem according to
industry analysts is that the power companies employ many workers who
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