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The
spent fuel cask will be moved from the dome-shaped reactor building
using a heavy-duty overhead crane. A special “crawler” vehicle (not
pictured) will move the fuel cask to a secure storage pad.
Early nuclear power plants in the United States were custom designs, but the
LaCrosse Boiling Water Reactor
in Wisconsin was truly unique in both its design and construction. That
uniqueness has carried over into the work to decommission and dismantle
the plant.
Owned
by the Dairyland Power Cooperative, the facility on the Mississippi
River near Genoa, Wisconsin, is very small -- producing just 50
megawatts of electricity -- compared to 1,000 or more megawatts from
later reactor designs. It was one of several demonstration reactors
funded, in part, by the Atomic Energy Commission, the predecessor to the
NRC. The plant was completed in 1967 and operated until April 1987. It
was the only reactor built by Allis Chalmers, a company best known until
the mid-1980s for its tractors and farm equipment.
In
the 25 years since the plant was shut down, the NRC has monitored and
inspected activities at the plant to assure continued protection of
public safety and the environment. NRC requirements have also remained
in place to maintain security at the facility.
Since
shutdown, the plant has been maintained in a safe and secure condition
until the plant can be fully decommissioned. In 2007 the 310-ton reactor
vessel was removed from the plant and shipped to South Carolina for
permanent disposal.
Spent
fuel from the reactor’s 20 years of operation has been safely housed in
the plant’s spent fuel storage pool. The Dairyland Power Cooperative
has been developing plans over the past several years to transfer that
fuel into five concrete and steel storage casks for interim storage on a
specially constructed concrete pad at the site. Similar dry cask
storage systems are in use at about 65 sites across the country.
Moving
that fuel, however, has posed special challenges for this unique
facility. The pool holding the spent fuel is too small to accommodate
the cask used to load and transfer the spent fuel. Faced with the lack
of space in the spent fuel pool itself, LaCrosse engineers devised a
unique solution of converting the structure that formerly housed the
reactor into a cask loading pool. The former reactor structure, which
adjoins the spent fuel storage pool, will be filled with water for the
cask loading. Once the cask is loaded, the loading pool will be drained
and a gateway opened. A heavy-load overhead crane will move the cask
outside the loading area.
Throughout
the process, NRC engineers and inspectors have evaluated each step,
including review of the construction of the storage pad and
modifications to form the cask loading pool. All activities are assessed
to assure that the unique concepts can be safely implemented for
workers, the public, and the environment.
Before
actually loading and moving the spent fuel, plant personnel are
performing “dry runs” without actually loading the fuel assemblies to
assure that the cask loading and transport equipment and procedures are
ready for safe movement of the fuel. NRC inspectors have been on site to
inspect these “dry run” activities.
The
actual fuel movements will begin later this summer and NRC inspectors
will be on hand to inspect the loading and movement of at least the
first of the five casks.
Christine Lipa, Chief
Materials Control, ISFSI and Decommissioning Branch
Region III
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