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Appendix E - Detailed Description of Alternative 1: DoFJRL-2001-11
I Full Removal and Disposal Rev. o t DtaU
Redlinc rikeout
1 • Foundation mat
2 • Cell drain header.
3
4 The demolition steps would be even more extensive adjacent to the rail tunnel, adjacent to
5 cell 10, and at each end of the building.
6
7 E.2.1.4 Excavate Outside Building to Foundation Level. After demolition would have
8 reached the anyon dcck , the area on each side of 221-U would be
9 excavated to the foundation level. This would allow continuation of demolition of the building.
10 Clean material removed during this excavation would be stockpiled for later use as site backfill.
S 1 Contaminated soil, if encountered, would be taken to ERDF for disposal.
12
13 E.11.5 Demolish 221-U from Canyon to Foundation Level. Building segments above the
14 foundation mat could be dismantled from both ends, meeting at cells 9 and 10, which would be
15 demolished last. This would Icave the process cells covered to minimize water intrusion and
16 leave the cell drain header collection tank in cell 10 functional for as long as possible.
17
18 The foundation mat varies in thickness from 1.8 to 2.4 m (6 to 8 ft). It would be left in place
19 until the walls of the canyon were completely removed to provide a firm working surface, and to
20 avoid disturbing the cell drain header. The foundation slab would be cracked using expansive
^21 grout. Wire saws would be used to cut slab reinforcement prior to demolition.
22
23 After removal of the foundation mat, the only remaining structure would be the bottom of
24 cell 10, the termination of the cell drain header. The cell walls extend approximately 6 m(20 ft)
25 below the bottom of the foundation. The walls would be exposed, cut, and removed. The cell
26 floor slab would be removed similar to the foundation mat.
27
28 E.2.1.6 Excavate Soil Below 221-U. As part of the demolition of 221-U, the first 0.9 m (3 ft) of
29 soil below the foundation slab would be removed. This removal step would include demolition
30 of the cell drain header. This 0.6-m (2-ft)-diameter clay pipeline is encased in concrete. The
31 pipe would be grouted solid to contain contamination and then removed in blocks for disposal at
32 ERDF.
33
34 E.2.1.7 Demolition of External ['iping Around 221-U. Piping not already addressed in the
35 preparation of the complex step would be removed as part of the demolition steps for 221-U. In
36 addition to the miscellaneous piping to be removed, a portion of the exhaust air tunnel would be
37 removed. This tunnel is a reinforced structure connecting the canyon's air ventilation tunnel to
38 the stack and filter. The tunnel is approximately 60 m(200 ft) long and runs from the end of the
39 air tunnel in building section 3 to the fans. Approximately 23 m(75 ft) of the tunnel would be
40 demolished and removed as part of Alternative 1.
41
42 The ventilation stack is about 60 m (200 ft) from the back wall of the canyon and would not be
(0^'43 demolished in this option.
44
45
Final Feasibility Sradyjor the Canyon DkpoXtion Initiative (221 •U Facility)
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