Environmental Engineering Reference
In-Depth Information
different and the hope is that at least one of the two will
work. Both approaches have gone from failure to ever
larger failure, but each time a great deal has been learned
and enough people have been convinced that we now
knew how to do it so that the next step was funded. Some
call this a triumph of hope over experience. The hope is
for a cost-effective, emissions-free, large-scale source of
electricity. The world needs one, and those who argue for
fusion believe that it can deliver. The hoped-for schedule
is for a power plant by
. Cynics say that practical
fusion energy is
years in the future and will always be
so. I have been involved with major reviews of both
approaches and will give my views on both.
Inertial: The NIF project is the largest of three
approaches to inertial fusion and I will focus on it. The
program was started by the nuclear weapons part of the
DOE so that the performance of hydrogen bombs could
be understood without further testing. Funding for NIF
and its predecessors at LLNL has come from the DOE
s
weapons program rather than its energy or science pro-
grams. The goal
'
which is really
making what I call a micro-bomb go off. A small capsule
of deuterium and tritium a few millimeters in diameter
resides inside a larger chamber of a few centimeters in
size. A huge laser delivers a large amount of energy in a
short time to heat the walls of the larger chamber, and the
radiation emitted from those walls in turn drives the small
capsule to a very small size, increasing the density of the
gases inside to much higher density than lead and heating
it at the same time to very high temperatures required for
fusion to occur. This is called indirect drive and is what
is called
“
ignition,
”
