High Level Radioactive Wastes and
What is high level
- NRC definition "High-level radioactive
waste or HLW means (1) irradiated reactor fuel (usually called
spent fuel), (2) liquid wastes resulting from the operation of
the first cycle solvent extraction system, or equivalent, in
a facility for reprocessing irradiated reactor fuel, and (3)
solids into which such liquid wastes have been converted."
taken from Ahearne, J. F., 1997, radioactive Waste: The size
of the Problem; in Physics Today, June Issue. Reread this and
it boils down to old reactor fuel and weapons production material.
- about 40,000 - 48,000 tons of high level
waste presently exist.
- most of it is being stored on site.
- generates significant waste heat with time.
- in liquid, sludge and solid form.
- some of the liquids from reprocessing are
- half lives span 4-5 orders of magnitude.
Yucca Mountain is being planned for a 10,000 year time span!!
Who generates the
- defense department - biggest producer by
- nuclear power plants.
- medical facilities.
- limited industrial production .
- research facilities (often at Universities).
- pipes in certain areas accumulate scale that
You might think of advantages and disadvantages of each.
- inject into space.
- place into deep marine muds or subduction
- ice sheet disposal.
- stabilize into synthetic rock or ceramic.
- terrestrial geologic burial.
What factors would be desirable in a burial
site selection? GIS as a way to handle these complex siting problems.
Legislation and Yucca Mountain site:
- National Waste Terminal Storage Act 1976.
- Nuclear Waste Policy Act 1982.
- Nuclear Waste Policy Amendments Act 1987.
- 2002 Both Houses vote to designate Yucca
Mountain as the site for HLRW disposal.
- DOE and NRC are main federal players. The
state of Nevada also wants a role.
- The plan is that the first waste will be
shipped in 2010.
Geologic setting for the Yucca Mountain Repository:
- remote, without other uses.
- fragmental volcanic rock known as tuff, with
low intergrain permeability, but locally significant fracture
- areas of geologically recent seismicity and
igneous activity nearby.
- groundwater table > 600' deep.
The effects of a large earthquake, a dike with
magma intersecting the repository, and a rise in the groundwater
table have all been investigated. Some workers claim an earthquake
and/or associated tectonic stresses could cause fractures to close,
causing the groundwater table to elevate. Nevada's focus seems
to be on transport and the possibility of associated accidents.
at Yucca Mountain: High-Level Nuclear Waste in the United States
by Allison Macfarlane in The Earth Around Us; AGI. p. 283-299.
Links to relevant sites:
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