View Document Here - Hanford Site

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APPENDIX G
DETAILED DESCRIPTION OFALTERNATIVE 4:
ENTOMBMENT WITH INTERNALAND
EXTERNAL WASTE DISPOSAL
DOE/RL-2001-1 t
Rev. I Draft I3
Redline/Strikeout
This appendix presents a description of details for the Alternative 4 dispositioning of the
221-U Facility. Alternative 4 involves disposal of wastes into available spaces within the
interior of the 221-U Facility and placement of waste in a waste disposal area located within the
engineered fill around the building. When complete. Alternative 4 transforms the existing
221-U Facility and its surroundings into a permanent near-surface burial complex for Hanford
Site generated low-level wastes.
For this alternative, legacy equipment currently stered on the anvon deck
and in the process cells would be reduced in size and volume and then placed into the process
cells and grouted. The een5+en-ePerating deekcanvon deck and its three galleries would be
prepared for acceptance as a disposal site for low-level Class C or lower wastes. Waste would be
containerized by others prior to receipt at 221 U. After placement, the containers would be filled
with grout. Building voids not filled with waste would be grouted. The building and disposed
waste would be protected from water infiltration by an engineered barrier. The engineered
barrier would be placed on top of engineered fill and would cover the entire footprint of the
building. The side slopes of the engineered fill would be constructed with an erosion protection
layer. Together, these three elements make up the environmental cap. Adjacent facilities and
wastes sites that are located within the footprint of the environmental cap must be remediated to
support implementation of Alternative 4. The adjacent aboveground facilities would be
dispositioned as part of Alternative 4 activities. However, remediation of the wastes sites is not
included as part of Alternative 4.
The following key assumptions have been made in the development of this alternative:
This alternative does not account for the remediation of waste sites within the perimeter of
the environmental cap. It is assumed that these sites would be addressed by other projects in
time to implement Alternative 4. Remediation of waste sites beyond the Alternative 4
environmental cap footprint are also outside the Alternative 4 scope and would be addressed
by future projects using the remedial action alternative selected for the appropriate 200 Area
operable unit. For cost-estimating purposes, it is assumed that there are no contamination
Final Feasibility Stadyjor the Canyon Disposirion fnitialive (221-U Facility)
]une;lb3 G-1