The United States alone produces an average volume of commercial low-level
radioactive waste of about 500,000 cubic feet each year. That is a lot of waste!
This comes from a variety of places. Mainly though, it is produced by nuclear
power plants. This waste brings up a problem though. It is difficult to dispose
of radioactive materials for two reasons. One, some radioactive materials last
for thousands of years. Two, most radioactive materials are hazardous and can't
be stored with conventional means. Currently, there are a few proposals that
have been made to combat this problem. These include near-surface facilities,
mined cavities, and geological repositories. In the past, some countries dumped
radioactive waste into the sea. This is extremely hazardous to the environment.
Recently though, more practical ideas have been made to bury the waste. Before
the material is even considered for storage or disposal, it must be properly
packaged. This includes packing it into steel drums or concrete containers.
These containers are expected to provide physical containment for at least a
thousand years. If the waste is in a liquid state, it must be placed on a
special abosrbitent type of material and then placed into the containers. The
next step would be to transport the containers to the burial site. There are
several different types of diposal facilities proposed. One is a near-surface
facility. This facility is located within a few tens of meters from the surface.
These facilities include trenches, and engineered vaults. Another proposal is
mined cavities. These facilities are constructed inside mines and caverns. They
are either man-made or natural. The last proposal is called a geological
repository. These sites are located more than several hundred meters below the
surface in a stable geological formation(away from major fault lines and other
problem spots). After the site is located there are other steps in the disposal
process. It is proposed that the drums will be placed in groups of four. Around
these groups of four a frame will be built. The frames then will be placed
inside hard rock holes or caverns. This will then be covered with a special
backfill material that prevents the movement of groundwater.A fter all of this
is done, the site will be monitored for up to 100 years to detect any leakage of
radioactive material or any outside influences such as flooding. There have been
problems with past proposals though. These problems were caused mainly by the
acceptance of liquid waste. The liquid waste leaked out of it's containers much
easier than the solid waste. This waste then contaminated the ground water. In
other past proposals, some sites were "lost" and accidentally
discovered when construction began in the region. This was due to human error
and not structural problems. One other problem also experienced by landfills is
the availability of space. There aren't too many places to store radioactive
material safely and away from the general population. Also, the sites where it
is safe for storage are filling up. At this point in time, the most adequate and
logical type of radioactive waste management seems to be burying the material.
Although right now it is difficult to see if this method the best available.
Only future generations can tell. With further development of the space shuttle
program perhaps the method of burying waste will become obsolete.