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DOFJ[ti.-2001-I 1
Appendix I - Decommissioning Technology Applications [tev.0 D raft I;
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n 1 crane instability during the swing and after impact. The latter method is not recommended
2 because the target area is more difficult to hit and the ball may ricochet off the target and damage
3 adjacent structures while putting side leads on the crane boom. The flat slab may only be used in
4 the vertical drop mode, but offers the advantage of being able to shear through steel-neinforcing
5 rods as well as concrete.
6
7 The wrecking ball or slab is recommended for nottradioactive concrete structures less than 0.9 in
8 (3 ft) in thickness. It would be virtually impossible to control the release of radioactive dust
9 during demolition due to the access needed for the crane to drop or swing the ball. For
10 nonradioactive structures, the wrecking ball Is an effective method and provides good
11 fragmentation to expose reinforcing rods.
12
13 1.3.3 Backhoe-Mounted Rams
14
15 Backhoe-mounted rams are used for concrete structures less than 0.6 m(2 ft) thick with light
16 n:inforcement. The method is ideally suited for low-noise, low-vibration demolition. and for
17 interior demolition in confined areas. The equipment consists of an air- or hydraulic-operated
18 impact ram with a moil or chisel point mounted on a backhoe arm. With the ram head mounted
19 on a backhoe, the operator has approximately a 6- to 7.6-m (20- to 25-ft) reach and the ability to
20 position the ram in limited access structures. The ram is recommended for applications with
('-121 limited access for heavy equipment, such as a wrecking ball, and where blasting is not pcrtnitted.
22
23 I.3.4 Rock Splitter
24
25 The rock splitter is a method for fracturing concrete by hydraulically expanding a wedge into a
26 pre-drilled hole until tensile stresses are large enough to cause fracture. The tool consists of a
27 hydraulic cylinder that drives a wedge-shaped plug between two expandable guides (called
28 feathers) inserted in the pre-drilled hole. Concrete may be separated at the fracture line using a
29 backhoe-mounted air ram or similar equipment. The reinforcing rod in reinforced concrete must
30 be cut before separation is possible. The splitter is ideally suited for fracturing concrete in
31 limited access areas where large air rams cannot operate. Reinforced concrete sections up to
32 2.4 m (8 ft) thick may be cut with a single large unit. Reinforced concrete sections 3 m (10 ft)
33 thick will require two or more large units to operate simultaneously.
34
35 I33 Bristar Demolition Compound
36
37 Bristar concrete demolition compound is a chemically expanding compound that is poured into
38 pre-drilled holes and causes tensile fractures in the concrete upon hardening. Bristar is a
39 proprietary compound of limestone, siliceous material, gypsum, and slag. Cracks will form and
40 propagate along the fracture line. The crack width will range between 0.63 cm (0.25 in.) after
41 10 hours to almost 5 cm (2 in.) after 15 hours. The fractured burden may then be removed with a
42 paving breaker, backhoe, or bucket loader. If a reinforcing rod is encountered, it must be cut
43 separately. The compound is not classified as a hazardous substance and can be readily stored
44 and handled. Bristar is suited for use on massive nonreinforced concrete structures where noise,
Final Feasibility Study jor the Canyon Disposition fnitiative (221-U Facility)
^ luas 2,003 I-11