Nuclear energy is the only source of electricity that
comprehensively takes responsibility for its associated waste. The nuclear fuel cycle, from the power plant
forward, is designed to continually shield, and isolate, used fuel from the
ambient environment. This characteristic
separates nuclear from all fossil, and even renewable, energy resources. Virtually every industrial activity in an advanced
civilization creates potentially toxic substances. This includes non-combustion
renewable energy, such as wind and solar. We can, and should, responsibly manage all such residues.
Used nuclear fuel is first stored in a pool of
water to allow the fastest decaying isotopes including many of the heat-generating
byproducts, to decay and cool down.
While used fuel is in storage, radiation is attenuated to very low levels by a few inches of
barrier, be it water, steel, or concrete. When
used fuel has decayed to about 75% to 85% of its original level, it is moved
from pools into dry casks.
Casks are inspected and tested in accordance
with stringent federal Nuclear Regulatory Commission (“NRC”) regulations to
assure they consistently contain radiation.
Spent fuel
containers of the same general type used in Wisconsin and throughout the U.S.
were present at the Fukushima tsunami site, and came through unscathed. The casks will easily last for 100 years and
probably much longer. A NRC Environmental Impact Statement recently concluded that used nuclear fuel can
be safely managed in dry casks indefinitely.'
Although there may well
be better uses for used nuclear fuel (please see the Q & A on what “advanced
nuclear” means), the consensus of scientists who have studied the question is
that, if we choose to treat spent fuel as a “waste” instead of a resource, it
can be isolated from the biosphere by putting it into the earth’s crust in zones
that have been stable and dry for millions of years, and will be stable and dry
for millions more. Such disposal is
already being pursued across the world.
Scientifically, it is reasonable to be confident about this kind
of disposal because natural
nuclear reactors operated on earth for hundreds of
thousands of years while life was evolving, and the associated byproducts,
although they developed in a water saturated zone, have moved only about 10
feet in the ensuing billion + years.
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