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Appendix G- Detailed Description of Alternative 4: DoEIRt.-2003-11
Entombment with Internal and External Waste Disposal Rev. l DraftJ
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I separated from each other by an approximately 0.75-m (2.5-ft)-thick lift of grout. The grout
2 layer provides important shielding to limit operation staff exposure to radiation from the wastes
3 in the layers below. Grout amendments, such as fly ash or zeolite clays, would be considered for
4 the grout to reduce potential for leaching of radioactive isotopes. A summary of steps involved
S for this part of Alternative 4 follows.
6
7 G.2.2.I Modify Canyon End Walls. In preparation for waste placement in the canyon, the end
8 walls of the building must be modified. A gridwork of steel bcams would be installed on both
9 the northeast and southwest end walls. This grid would be dcsigned to resist seismic forces and
10 loads applied during the complex's operation pcriod. For the southwest end wall, the
11 modification would include saw cutting an opening in the concrete wall. This opening would be
12 sized to accept the waste containers moved by a forklift. The opening would be covered with a
13 rollup door. The wall's steel beam gridwork would be designed to allow the rollup door to be
14 moved upwards level by level as the waste is placed within the canyon. The gridwork would be
15 anchored to the roof siab and surrounding reinforced walls. 71rough-bolting would connect the
16 gridwork to the unreinforced concrete end wall.
17
18 G.2.2.2 Fill Ganyan Canvon deck and Craneway with Waste. The eaxyen
19 canvon deck would be filled with a total of four layers of waste containers. The
20 first three layers would hold a estimated 160 cargo containers each, for a total of 480 containers.
21 The container placement would start at the northeast end of the canyon and advance towards the
22 southwest end. Each layer would be completed prior to placement beginning on the next layer
23 up. This approach would ensure that them is not a large differential in loading of adjacent
24 building sections.
25
26 Containers would be grouted both inside the container and around their exterior. It is envisioned
27 that grouting would occur roughly every 12 m (40 ft) of building length. Containers would be
28 placed using a forklift with adequate shielding to limit operator exposure to an acceptable level.
29 The containers would be placed two abreast across the canyon deck width. In this manner, the
30 forklift could place the containers without making a 90-degree turn, which would be difficult in
31 the limited width of the canyon deck.
32
33 As part of the grouting effort, a 0.75-m (2.5-ft)-thick layer of grout would be placed on top of the
34 filled containers. This layer would act as both shielding and a working surface for the next layer
35 of containers. Grout amendments, such as fly ash or zeolite clays, would be considered for the
36 grout to reduce potential for leaching of radioactive isotopes. In the final design, a reinforced
37 concrete slab may be installed as the top section of the grout layer. The concrete slab provides a
38 smoother surface for operation of the forklifts during waste placement of the next layer. The
39 grout, or possibly reinforced concrete slab, would be designed for the whccl loads of the forklift.
40
41 The next waste placement would be inside the craneway. An opening in the southwest end wall
42 would be cut to provide access to the cranaway. Guide rails would be installed and cargo
(-,\43 containers delivered into the craneway similar to waste placement in the galleries.
44 Approximately 39 containers could be placed in the craneway. The containers would be grouted
45 inside and out as was done in the galleries.
Final Feasibility Study jor Jhe Canyon Disposition )nitiativt (22 )-U Facility)
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