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Appendix F - Detailed Description of Alternative 3: DOFJ[u.2001-11
Entombment with Internal Waste Disposal Rev. A t Draft B
Redline/Strikeout
1 reinforced concrete slab roof. There is a concrete masonry perimeter wall supported on a
2 basement wall, with interior masonry walls within the building. The roof is a reinforced concrete
3 slab similar to tbe floors. The third floor is a chemical makeup area with floor slabs up to 0.3 m
4 (1 ft) thick that support chemical tanks.
5
6 Additional building features included in the demoiition are a stack on the roof (296-U-10). an
7 elevator, a second floor vault, and mechanical equipment in the basement. Demolition would
8 use typical building demolition techniques. The resulting rubble would be left in place alongside
9 221-U and the area filled and compacted as pan of the clean fill around the canyon.
10
11 F.lA.1.3 Decontamination and Decommissioning (D&D) Stairways on 221-U Building.
12 Eight stairwells on the northwest side of 221-U are light construction and would be demolished
13 using typical building demolition techniques. Ten stairwells on the southeast side of 221-U are
14 thick wall, lightly reinforced concrete construction. The heavier construction of these stairwells
15 would be factored into the demolition costs. Any contamination found in the stairwells on the
16 canyon's southeast side would be fixed in place prior to demolition. All stairwell demolition
17 waste would be disposed adjacent to 221-U where it would be protected from infiltration by the
18 environmental barrier.
19
20 F.lA.1.4 D&D Other Aboveground Structures. All other aboveground structures identified
^21 in Assumption 2 at the beginning of this appendix that are within the footprint of the 221-U
22 environmental cap would be decommissioned as part of Alternative 3 activities.
23
24 F.lA.2 D&D of Buried Piping. Buried piping not already addressed in the preparation of the
25 complex function would be arouted in place or removed prior to the placement of engineered fill
26 around 221-U,pased on the outcome of risk assessment work . In addition to the miscellaneous
27 piping to be removed, the exhaust ventilation tunnel would be removed. This tunnel is a
28 reinforced tunnel connecting the canyon air ventilation tunnel to the stack and filter. The tunnel
29 is approximately 60 in long and runs from the end of the air tunnel in Section 3 to the fans.
30
31 F.1A.3 Confirm Remediated Waste Sites Within Environmental Cap Footprint.
32 Alternative 3 includes covering 221-U with an environmental cap. It Is assumed that the waste
33 sites located within the environmental cap, as identified in Assumption 3 at the beginning of this
34 appendix, would be remediated by other projects prior to the start of Alternative 3 and
35 construction of the environmental cap. All remediation wastes would be disposed at ERDF.
36
37 F.1.4.4 Confirm Well Decommissioning. Three wells are located within the footprint of the
38 environmental cap. It is assumed that these wells would be decommissioned by other projects
39 prior to the start of Alternative 3. The wells are 299-W 19-8, 299-W 19-55, and 299-W19-98.
40 Their prior removal would be confirmed as part of Alternative 3.
41
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Fieaf Feasibility Studyfar the Canyon Disposition Initictive (2I )-U Facility)
, 2 00 1 F-14