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The
waste packages to be used inside
Yucca Mountain will consist of
inner vessels, outer corrosion
barriers, and a series of lids. Click
the image to enlarge.
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In 2005, the Office of Civilian
Radioactive Waste decided to further
enhance safety processes relating
to waste canisters and waste handling.
Prior to leaving a nuclear power
plant, spent fuel rods will be placed
in a canister
called a Transportation, Aging and
Disposal (TAD) canister. Under normal
conditions, the rods will permanently
remain in the TAD canister.
The TAD will be placed in another outer container, depending on where in the process the waste is: transportation, aging or disposal.
- Prior to leaving a facility for
Yucca Mountain, the TAD would be
placed in a transportation cask,
which is radiation-shielded, sturdy,
and impact-resistant. The packages
would be shipped primarily by train.
- At the Yucca Mountain site,
the TADs would be removed from
the transportation cask and placed
in aging or emplacement packages.
The TAD canister transfer takes
place inside surface facilities
using remote-controlled equipment.
- TAD canisters that need to
cool off, or age, before going
into the repository will be placed
in aging canisters and stored
on aging pads located near the
waste handling facilities.
- TAD canisters ready to go directly
into the repository will be placed
in an additional, corrosion-resistant
disposal package.
Using radiation-shielded TAD canisters is simpler, safer and more cost-effective than other proposals considered by OCRWM. The TADs approach eliminates repetitive waste handling activities and simplifies facility design and operations. Prior plans called for shipping waste in various types of canisters which would require workers to transfer and process waste up to four times per fuel assembly.
The Department of Energy is currently working with vendors to design TAD canisters that meet Nuclear Regulatory Commission requirements.
U.S. Navy spent fuel and glass logs of high-level waste will use their own disposable, TAD-like canisters.
The Yucca Mountain Repository is designed to hold 70,000 metric tons of spent nuclear fuel and high-level radioactive waste in metal containers.
The Department of Energy will use a "canister within a canister" approach consisting of three containers - nested inside one another - to safely dispose of radioactive waste. First, the TAD canister that holds the waste will sit inside a stainless steel canister designed and built to provide additional strength to the package. The package is then placed in the outermost canister consisting of nickel alloy (Alloy 22), which is highly resistant to corrosion.
The Yucca Mountain waste canisters will:
- Isolate radioactive particles from the outside environment
- Prevent physical and chemical reactions within the canister
- Manage the heat of the radioactive content
- Remain intact during movement, including loading, transportation and emplacement.
Last reviewed: 04/08
Repository Engineering and Design Overview:
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