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DOFlRL-2001-11
I Appendix I - Decommissioning Technology Applications Rev. O t Dr^ft B
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1 and easily set up. In hazardous environments, the torch can be mounted on a remotely opcrated
2 positioner to reduce the potential for exposures to workers.
3
4 An oxygen-buming torch is ordinarily unable to cut aluminum and other nonferrous or
5 ferrous/high-pcrcent alloy metals, such as stainless steel.
6
7 1.2.2.3 Flame Cutting. Flame cutting, a technique used to cut concrete, involves a thermite
8 reaction in which a powdered mixture of iron and aluminum oxidizes in a pure oxygen jet. As
9 the high temperature of the jet (as high as 16,000°F) causes the concrete to decompose, the mass
10 flow rate through the flame-cutting nozzle acts to clear the debris from the work piece area. Any
l 1 reinforcing rods in the concrete add iron to the reaction, sustaining the flame and assisting the
12 reaction.
13
14 Heat and smoke that result from the process can be removed with a blower and directed through
15 a flexible duct that houses a water logger to hold down smoke particulates. The high operating
16 temperatures preclude the use of HEPA filters for contamination control, making the flame-
17 cutting technique poor for use in contaminated environments.
18
19 I.2.2.4 Thermite Reaction ILance. The thetmite reaction lance is an iron pipe packed with a
20 combination of steel, aluminum, and magnesium wires through which a flow of oxygen gas is
("",21 maintained. The lance cuts are achieved by a themtite reaction at the tip of the pipe in which all
22 constituents are completely consumed. Temperatures at the tip range from 4,000°F to 10,000°F
23 depending on the environment (air or underwater) and the ambient condidons of that
24 environment. The lance is ignited in air by a high-temperature source such as an oxygen-burning
25 torch or an electric arc. Typical lances are 3.2 m ( 10.5 ft) in length and have outside diameters
26 of 0.38 in., 0.5 in., 0.63 in., or 0.69 in. Use of the lance is practical only in a hand-held mode.
27 The lance operator must also be provided with complete fireproof protective clothing and face
28 shield.
29
30 1.2.2.5 Arc Saw Cutting. The atC saw is an extension of nonconsumable melting electrode
31 technology. It is a circular, toothless saw blade that cuts any conducting metal without physical
32 contact with the work piece. The cutting action is achieved by maintaining a high-current
33 electric arc between the blade and the material being cut. The blade can be made of any
34 electrically conductive material (e.g.. tool steel, mild steel, or copper) with equal success. The
35 depth of cut is limited by blade diameter, and a maximum cut of 0.9 m (3 ft) is considered
36 achievable.
37
38 1.23 Other Techniques
39
40 Abrasive water-jet cutting is a technique that is neither mechanical nor thermal. In this
41 technique, the material is eroded away by an abrasive. The abrasive water-jet cutting technique
42 involves the use of highly pressurized water (as high as 379,225 kPa [55,000 psi]). The water is
("^N43 pressurized by a hydraulically driven intensifier pump. The water tiows through a chamber
44 where it is mixed with an abrasive, the most common being crushed garnet. This mixture of
45 water and abrasive is then forced through a wear-resistant nozzle with a small orifice, which
Final Feasibility Study jor the Canyon Disposltion )nitiative (221-U Facility)
June2003 1-9