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Appendix H - Detailed Description of Alternative 6: DoEI[tL-2oo1-11
Close in Place - Collapsed Structure 1tev.18 Draft II
Redline/5trikeout
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2 11.13.1.2 221-U Facility Modifications. Limited modifications to the 221-U Facility are
3 necessary to accomplish equipment removal and decontamination operations. Facility modifications
4 primarily involve disconnecting and blanking utility and electrical lines where they are no longer
5 required and installing temporary utilities that would be required to support planned operations.
6 The change room at the northeast end of the operating gallery would be renovated and
7 established as the main access and egress point for canyon operations. Water and drain lines for
8 the change room facility could tied into the active systems in the 271-U Office Building.
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10 Additional 480-volt electrical service requirements would be installed, as necessary, to support
11 portable ventilation requirements and selected decontamination equipment, such as air
12 compressors for pneumatic tools and temporary greenhouse structures. In addition, 480-volt
13 ^ electrical service would be installed to support w erte ,.-Messi..o and
14 decontamination/disassembly operations.
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16 H.13.13 Add New Air Handler. Installation of a new air-handling unit on the roof of 221-U
17 is a major modification that would oeeurmav or may not be rrnuired based on further analvsis of
18 tasks and seauencine of events that will be done during design . If needed. .:Ahe unit would be
19 located on the northeast end of the building and require penetrations through the roof for air duct
20 connections.
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22 H.1.3.1.4 Grout Cell Drain Header and Vent Tunnel. The cell drain header would be filled
23 with cement grout during the building preparation phase once the new air handler is installed and
24 operational. Grouting would fill the 0.6-m (24-in.)-diameter void space and encapsulate any
25 contamination present in the pipe. After the connecting pipes to cell 10 are sealed, grout would
26 be pumped in from both ends of the cell drain header. Because the cell drain header flows
27 downward from the building ends toward cell 10, a liquid-consistency grout would flow through
28 the header and require very little pumping pressure. Drainage openings in each process cell
29 would act as air vents, and the pressure would be regulated so that the grout would be visible in
30 the process cell drains, but would not rise in the cells. After this operation, any liquid within the
31 canyon would not automatically flow to cell 10.
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33 *Vestei.e¢acy equipment placement is not planned for the ventilation tunnel due to limited
34 accessibility of this area. Therefore, the ventilation tunnel would be grouted to eliminate voids
35 in the building structure. Holcs would be angle drilled through to canyon's exterior wall to allow
36 access to the ventilation tunnel for gt+outing. Free-flowing grout would be pumped through these
37 holes to fill the ventilation tunnel. The grouting would be completed in lifts to allow time for
38 heat dissipation during grout curing. The tunnel is planned to be filled with grout to the
39 maximum extent possible. It is estimated that the ventilation tunnel would require approximately
40 2,300 m3 (3,000 yd3) of grout. During final design, the decision to fill the tunnel should be
41 revisited. Preliminary structural calculations (Smyth 2001) show that the exteriorwall of the
42 tunnel may have sufficient strength to withstand later external pressures from fili heights
43 associated with burying the canyon building and, therefore, not require grouting.
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Final Feasibility Study/or she Canyon Disposition Initiative (221•tJ Facility)
J une 1oo^ H-9