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Appendix G - Detailed DescrIptioti tif Alternative 4: DoEIR1.2001-11
' Entombment with Internal and External Waste Disposal Rev. I Draftli
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1
2 Some removed equipment may be identified as reusable. Unneeded material from the gallery
3 would be size reduced and placed in ERDF boxes for disposal at ERDF. It may be desirable to
4 containerize some of this material for placement in the electrical gallery. This approach could be
5 used as a test run of the procedure for placing waste in these galleries. However, for the cost
6 estimate, all waste from the gallery is assumed to be disposed at ERDF.
7
8 G.1.3.3 Demolition or Railroad Tunnel. To leave the tunnel in place would mean an
9 unnecessary increase in the size of the environmental cap. This alternative includes removal of
10 the railroad tunnel. The contaminated concrete would be disposed at ERDF.
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12 The tunnel, which allowed train access into cell 3, extends 46 m(150 ft) westward from the
13 northwest side of the canyon building. The tunnel is a reinforced concrete structure with a soil
14 cover about 1.5 in (5 ft) thick. There are unreinforced wing-wall retaining structures at the end
15 of the tunnel. The tunnel is assumed to have light surface contamination that could be fixed in
16 place with fixative application. It is assumed that a backhoe with a processor would be used for
17 demolition.
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19 Demolition of the railroad tunnel would allow truck access to cell 3 without safety hazards
20 associated with backing down the long, narrow railroad tunnel. Also, part of the railroad tunnel
("4\21 work is construction of a truck door at the tunnel's connection to 221-U (cell 3). This door
22 would allow access to the building without disrupting ventilation of the canyon.
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24 The new access door to cell 3 at the tunnel would allow placement of containerized and possibly
25 long-length waste. After cell 3 is full of waste, it would be filled with cement grout and the.
26 cover blocks would be permanently replaced. l.ike the other process cells, the cover blocks
27 would be drilled and pressure grouted in place and the bails would be removed.
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29 G.1.3A Hot Pipe Trench. The hot pipe trench is assumed to be contaminated. A review of
30 historical photographs of the trench indicates that the trench contains intertwined, small-diameter
31 piping. Waste placement is not planned for the hot pipe trench due to limited available space.
32 Instead, the trench would be filled with grout to eliminate voids in the building structure. The
33 initial preparation step for grouting the trench would be coating the interior surfaces with a
34 fixative to contain surface contamination. After the coating is cured, the hot pipe trench would
35 be grouted. Due to the maze of piping, it is assumed that no contaminated equipment or waste
36 would be disposed to the hot pipe trench. The interior volume of the pipes encased by the grout
37 would be very small and therefore assumed to have no effect on the stability of 221-U. The
38 volume of grout needed to fill the trench, 800 tns (1,100 yds), is estimated as 75% of its overall
39 volume. The trench cover blocks would then be permanently replaced. The cover blocks would
40 be pressure grouted as described for the process cell cover blocks. After grouting, the bails
41 would be removed from the hot pipe trench cover blocks.
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n43 G.13.5 Remove Surface Contamination. To safely enter the building during its operational
44 phase in this aitemative, contamination survey results would be used to identify where
45 decontamination activities are needed. Contamination would either be removed or fixed to the
Final Feasibility Study jor the Canyon D'uposlrion lnitiative (211-U Facility)
Luas:.401 G-12