To know Africa is to appreciate its complexity. As the
famous physiology professor, Jared Diamond, has written,
Africa is
the sole continent to span both the north and south temperate zones;
it is also unique in its human diversity, for one quarter
of the world’s languages are spoken only in Africa. These two factors
explain a great deal about Africa today. Domesticated plants
and animals from the Fertile Crescent in western Asia spread south
(into Africa) across climate zones much more slowly than east
and west. Thus, pockets of human hunter-gatherers persisted,
even as Bantu-speaking African farmers slowly expanded their territory
south, between 1,000 B.C.E. and 1,000 A.C.E. This long human
presence in Africa has allowed the big animals to adapt and survive today,
and it has also encouraged infectious human diseases to thrive,
such as malaria, yellow fever, trypanosomiasis and AIDS.
One
might well ask, is Africa, or at least its tropical core, doomed
eternally to wars, poverty and devastating diseases?
One could also
ask, why is it that most Westerners who visit Africa return with
feelings of optimism and compassion? I think the solution lies
in Africa’s children. Our investment in their education
would be far less costly than trying to stop ugly wars in the
long run,
far more compassionate, and crucial for reducing the galloping
birth rate in Africa.
Over
the past 2 or 3 years the world has been rethinking its
position on nuclear power. One reason is that the costs
of oil and natural gas have shot up dramatically. Another
reason is that
nuclear fission does not release carbon dioxide, so
it has been described as an “environmentally friendly” source
of electricity. Skeptics, however, say that it is a poor investment
and a worse security risk. Let us examine some crucial facts:
In
the past half-century nuclear energy has emerged from behind
a wall of military secrecy to become a widely used
source of commercial
electricity. Despite the high construction costs and special
risks, there are now 441 reactors working in 30 nations. Almost
half of
these reactors are in Europe. While the nuclear share of total
electrical output is less than 20% in USA, there are 6 European
countries (France,
Lithuania, Slovakia, Belgium, Sweden and the Ukraine), in which
it exceeds 50%, and many more where it exceeds 30%. Nuclear energy
advocates urge the world to increase nuclear power output 10-fold
by the end of the century, but few are heeding this advice. Still,
because most reactors now in use are over 20 years old at a time
of growing concern over the climate change issue, there is a
consensus that we should maintain the nuclear share of electrical
output at
the current level as a “bridge” to future clean energy
technologies. Even this proposal upsets many environmentalists,
who claim that nuclear power is a false solution, pushed as part
of a clever public relations campaign by nuclear industrial interests.
Reasons given for this viewpoint are many, but they boil down to
two central issues: concerns over the safety and security of storing
or reprocessing “spent” isotopes, and fear that we will
allow ourselves to be distracted from the need to invest in moderate-scale,
renewable energy systems. Let us look into both issues more deeply.
At
first glance it would seem relatively straightforward to develop
a sound plan for disposing of long-lived radioactive
waste by simply
digging a deep mine, store the material in robust containers,
and rely on geology to keep it out of the biosphere for tens
of thousands
of years. The USA is one of only two countries to date that have
chosen sites for this. Ours is under Yucca Mountain in Nevada.
The design relies upon elevation and waste heat to keep water
out of
the repository, which would be carved out of volcanic tuff. However,
critics charge that the site isn’t dry enough, that the rock
is fractured and leaky, and the oxidizing environment would corrode
the waste containers. So far we have spent $5 billion just planning
for this uncertain site, for which the opening date might be
sometime after 2012, and its capacity is not sufficient to handle
all 120,000
metric tons of waste potentially needed for reactors currently
in use. This is not a good beginning (6).
Finland also has a designated site; it would handle 5,600 metric
tons at a projected cost of $3 billion. Sweden hopes to choose a
site by 2008, which would house 8,000 metric tons of spent fuel
at a projected cost of $2.5 billion. France, Japan and Russia are
exploring possible burial sites, but they are keeping their wastes
near the surface indefinitely while they decide what to do next.
All three now reprocess spent fuel to extract usable isotopes. They
argue that this conserves fuel and reduces waste, but others reply
that this approach is more costly and increases security risks (6).
The other safety concern is with the reliability of the reactor
itself. Memories of Three Mile Island and Chernobyl still linger
after many years. Fortunately, the industry has thoroughly tested
new, simpler systems that automatically kick in if anything should
go wrong. One example, known as the pebble bed reactor, discovered
at the University of Wisconsin and resurrected in Germany and China,
is considered inherently safe because its tiny cores are sparsely
loaded. In addition it exploits a natural ability of uranium-238,
the nonfissile isotope that makes up the bulk of uranium fuel.
Finally, we return to the problem of our fear of distraction:
This has already driven a rift between highly respected environmentalists
in the U.K. Purists are determined to direct all of our energies
into developing wind and solar energy, fearing that any expansion
of nuclear power would sap the former initiatives. Pragmatists
doubt that we will have sufficient energy from wind and solar
power to satisfy our growing appetite without using nuclear
energy for several more decades to fill the potential energy
gap. The pragmatists seem to be holding sway in Europe, while
the purists dominate the scene in North America. When realistic
concerns about nuclear waste disposal are added to hypothetical
concerns about nuclear terrorism, there remains little enthusiasm
for building new nuclear plants in U.S.A., let alone maintaining
the old ones.
