Nuclear plant
used fuel storage capacity. Nuclear plants were
designed to store at least a decade’s worth of used fuel. The
federal government was to begin moving used fuel from plant
sites to a centralized storage facility in 1998, as mandated
by the Nuclear Waste Policy Act of 1982. This delay means that
nuclear plants must store more used fuel than expected and
longer than originally intended. By 2010, the earliest opening
date for a repository, 78 plants will have no room left in
their used fuel pools.
Used fuel
pools: safe storage inside plants. At most plants, used
fuel is stored in steel-lined, concrete vaults filled with
water. In these used fuel pools, the water acts as a natural
barrier for radiation from the fuel assemblies. The water also
keeps the fuel cool while the fuel decays—becomes less
radioactive. The water itself never leaves the inside of the
plant’s concrete building.
Dry storage
facilities: safe storage outside plants. Since 1986, more
than a dozen U.S. plants, including several shutdown units,
have supplemented their storage capacity by building
above-ground, dry storage facilities. By mid-1999, nearly 150
of these containers were being used in the United States.
Other countries also have safely and successfully stored used
fuel above ground since the mid-1970s.
Dry storage
container construction. Containers are made of steel or
steel-reinforced concrete, 18 or more inches thick, as well as
lead, which serve as proven, effective radiation shields. Once
loaded with used fuel assemblies, the containers are stored
horizontally in a concrete vault, or they stand upright on a
three-foot-thick concrete pad. The containers are designed and
tested to prevent the release of radioactivity under the most
extreme conditions—earthquakes, tornadoes, hurricanes, floods
and sabotage—and are naturally cooled and
ventilated.
NRC design
approval and licensing of dry storage containers. Each
container design must be approved by the U.S. Nuclear
Regulatory Commission. While the NRC had determined that used
fuel can be safely stored at plants sites for at least 30
years beyond the licensed operating life of the plant, the
agency requires that dry storage containers be constantly
monitored and relicensed every 20 years.
Dry storage
systems are only a temporary solution. Dry storage
containers are expensive, ranging from $500,000 for a
container stored in a vault to more than $1 million for a
container stored outside on a concrete pad. Will public
utility commissions allow utilities to recover the cost of
this extra storage system from customers when the customers
already have contributed billions of dollars into the
federally mandated Nuclear Waste Fund? Also, state and local
officials are concerned that, unless the U.S. Department of
Energy fulfills its legal obligation to provide used fuel
disposal, on-site dry storage facilities will become, in
effect, repositories themselves. Certain states have moved to
limit the development or expansion of these facilities or to
place conditions on the utilities in exchange for
approval.
