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Some of the electricity used in homes across our nation is made with
nuclear fuel in reactors at power plants. When the fuel that is used
to make electricity at the power plants can no longer produce electricity
efficiently, it is removed from the reactors. This used fuel is called
spent fuel.
Some nuclear materials used for national defense create waste. This
waste is called high-level radioactive waste.
These highly radioactive materials must be protected so they won’t
harm people or the environment.
Scientists have studied different ways to dispose of this radioactive
material. Currently, it is stored at government sites and at the power
plants where it is made. However, a permanent disposal place is needed.
Most scientists around the world agree that the best place to put
this radioactive material is in a facility deep underground. This
type of facility is called a geologic repository.
The U.S. Department of Energy (DOE) has studied Yucca Mountain for
more than two decades. In 2002, the secretary of energy and then the
president recommended the site as suitable for a geologic repository.
Congress subsequently supported this recommendation, officially designating
Yucca Mountain for a proposed repository.
Now the DOE can submit a license application to the Nuclear Regulatory
Commission, which has three to four years to decide whether to grant
a license to construct a repository.
Yucca Mountain is about 100 miles northwest of Las Vegas, Nevada,
on land owned by the federal government.
No one lives on Yucca Mountain.
The area has a very dry climate — receiving a combined average
of about 7.5 inches of precipitation per year. Approximately 95% of
this total either runs off, evaporates, or is taken up by the desert
vegetation.
Yucca Mountain has a very deep water table. If a repository is built
at Yucca Mountain, it would be located about 1,000 feet below the
surface and 1,000 feet above the water table. So any water that does
not run off or evaporate at the surface would have to move down nearly
1,000 feet before reaching the repository and then another 1,000 feet
before it reached the water table.
The dry climate is an important feature because water is the primary
way by which radioactive material could move from a repository.
The basic idea of geologic disposal is to place carefully packaged
radioactive materials in tunnels deep underground.
This method relies on a series of barriers that prevent or slow the
movement of radioactive materials from a repository. These barriers
include natural ones, such as thick unsaturated rock, and man-made,
or engineered, ones. These barriers also would greatly reduce the
total amount of any radioactivity that could eventually reach the
water table where people might pump it from the ground and use it.
The current design for the potential repository calls for spent nuclear
fuel and high-level radioactive waste to travel to Yucca Mountain
by truck or rail in specially designed, shielded shipping containers.
Once these materials arrive at the repository, they would be removed
from the shipping containers and placed in double-layered, corrosion-resistant
packages for burying underground. Special rail cars would carry them
underground, and remotely controlled equipment would place them on
supports in an underground tunnel.
Once the materials are placed in the repository, scientists would
continue to check that everything is working the way it should during
the performance confirmation period.
Before the DOE could construct a geologic repository and begin waste
emplacement, the Department must submit a license application, go
through a multi-year review and public hearing process, and then receive
a construction authorization from the Nuclear Regulatory Commission
(NRC).
The hearing process would focus on public health and safety. Along
with the review process, the hearing process is expected to take a
minimum of three years after the DOE submits a license application.
If the DOE receives a construction authorization, it would have to
complete initial construction, and apply for and receive a license
from the NRC before any waste could be received or emplaced. This
includes demonstrating to the NRC that there is a reasonable expectation
a repository designed for the Yucca Mountain site could protect health
and safety for 10,000 years after the repository is closed.
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