Environmental Engineering Reference
In-Depth Information
a by-product in nuclear reactions, is recovered during reprocessing and
can be used to make nuclear weapons. The philosophy was that the less
plutonium there is in the world, the lower the danger is that the element
will fall into the wrong hands. Reprocessing is now allowed in the United
States, but there are no operating reprocessing facilities.
Reprocessing can potentially recover up to 95 percent of the pluto-
nium and remaining uranium in spent nuclear fuel, putting it into new
mixed-oxide fuel. Segregating the uranium and plutonium in this way
produces a reduction in long-term radioactivity within the remaining
waste because it is largely short-lived fi ssion products. It also reduces the
volume by more than 90 percent.
Reprocessing of civilian fuel from nuclear reactors is currently done
on a large scale in Britain, France, and Russia and an expanding scale
in Japan; soon it will be done in China and perhaps India. France is the
most successful reprocessor, recycling 28 percent (by mass) of its yearly
fuel use—7 percent within France and 21 percent in Russia.
Spent fuel rods are stored temporarily in shielded basins of water,
usually on-site. The water provides both cooling for the still-decaying
fi ssion products and shielding from the continuing radioactivity. After
many decades, the fuel rods may be moved to a dry-storage temporary
facility or dry cask storage, where the rods are stored in steel and con-
crete containers until their radioactivity decreases (decays) to levels safe
enough for further processing. This interim storage stage spans years or
decades or millennia, depending on the type of fuel. This means that a
power plant site, even when it has reached the end of its electricity-
generating life, must remain staffed to operate the cooling ponds, with
full security to prevent site intrusions and theft of the spent fuel rods.
Who is going to pay for this? Consider the cost of staffi ng for perhaps
100 years when there is no revenue stream from electrical generation to
cover this and no customers to carry the fi nancial burden. This problem
is only now starting to be realized because so few reactors have reached
the end of life in the United States. The major electrical utilities that own
and operate nuclear power plants have not considered this cost in their
balance sheets.
Much more daunting is the fact that the material will remain radioac-
tive for perhaps 100,000 years. No civilization has lasted for more than
one thousand years. No spoken or written language (to mark the site or
provide maintenance instructions, for example) has lasted more than a
couple of thousand years. No objects, metal tools, or vessels created by
humans have survived corrosion and structural failure for more than a
Search WWH ::




Custom Search