**Techniques or Technologies**

**Pressure Washing** - Usually used for decontamination, that utilizes a
stream of pressurized water up to 1,800 psi to remove loose
contamination for pickup by a suction nozzle. A wet-service vacuum unit
with filter is used to separate collected particulate from the
discharged effluent.

Includes the operations and maintenance activities such as making
repairs to components, replacing parts and components, inspection and
cleaning of equipment, and other tasks during the used of this
technology.

**Surface Wiping** - Usually used for decontamination, that includes
manual cleaning and wiping using non-aqueous cleaning solutions such as
detergent/surfactant, industrial strength 409 and Radiacwash.

**Concrete Scabbling** - Use of mechanical device used to remove
contaminated material from hard surfaces by removing top layer of the
material

The element also includes the operations and maintenance activities such
as making repairs to components, replacing parts and components,
inspection and cleaning of equipment, and other tasks during use of this
technology.

**Crushing/Size Reduction** - Use of mechanical device to reduce volume
or compact waste and materials. Some of these devices also include
cutting tools. Cost also includes the operations and maintenance
activities such as making repairs to components, replacing parts and
components, inspection and cleaning of equipment, and other tasks during
the use of this technology.

**Demolition by Explosives** - Demolition of building and facilities
using explosives such as dynamite.

**Mechanical Demolition** - Demolition of structures and facilities
using mechanical equipment.

**Controlled Blasting** - Demolition of structures and facilities using
explosive compounds placed into drilled holes to radially fracture the
material upon detonation. The spread of contamination is controlled with
blasting mats and water fog sprays and construction of contamination
envelope. "

**Hydraulic Shear** - Method is used to dismantle concrete or masonry
structure (e.g., wall, column, etc.) up to 2 ft. thick provided that a
light-medium duty front-end loader can be provided with ample working
room (the ability to segment reinforcing steel in the concrete is
limited to approximately 1.25" of metal thickness). The hydraulic tool
attachment on the wheel loader is used to crush and tear off pieces of
concrete and reinforcing steel with its crusher jaws (e.g., pincers).
Dust production can be controlled to an extent with ventilation or a
water fog spray. This method of dismantlement is used in areas when
vibration to surrounding structures is to be minimized which may
prohibit the use of an alternative method such as controlled blasting.

**Oxyacetylene Torch** - Generally, used to cut internal building
structures with metallic components (e.g., handrails, I-beams,
reinforcing steel) containing ferrous metals such as carbon steel or
cast iron. Standard oxyacetylene torches are generally unable to cut
through stainless steel, aluminum, and other nonferrous metals because
of the production of metallic oxides which can have a melting point
above that of the flame temperature. The ability to cut through thick
metal plating is dependent on the skill of the cutter and the
effectiveness of the oxidizing fuel mixture to clear away molten metal
and oxides from the kerf.

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**Oxy-Gasoline Torch** - This cutting method generates a flame
temperature which is several hundred degrees hotter (e.g., 1,500^0^F)
than an oxyacetylene torch. The fuel source is 87-octane unleaded
gasoline fed from a

2.5 gallon tank pressurized by a manual pump. Oxygen from a cylinder is
used as the oxidizing gas. Since gasoline burns at a higher flame
temperature and is cheaper on a heat content (e.g., \$/Btu) basis than
acetylene, this method is beginning to be considered in some
decommissioning work because of reported savings in cutting time and
fuel costs.

**Thermite Reaction Lance** - Thermite reaction lances are hand-held
iron pipes (e.g., 10.5 feet long) packed with oxidizable metal wires
such as aluminum, steel, or magnesium. Because all the metal components
are consumed during the reaction, the lance stubs are discarded when
they burn down to 2-3 feet in length. Compressed oxygen flowing through
an annulus in the pipe sustains the reaction at 4,000 - 10,000 ^o^F.
Since this is well above the melting point of most typical metal
building components, most metals may be cut using this method. The
practical cutting depth is restricted only by the ability of the cutter
to keep the kerf free of molten metal and oxides.

**Metal Powder ("Flame") Cutting** - Metal powder cutting, or more
commonly flame cutting, oxidizes a suspension of iron oxide and aluminum
powder in a stream of oxygen gas to produce a thermite reaction with
temperatures up to 16,000 ^o^F. At these temperatures, the flame tip
literally disintegrates concrete or masonry materials into a powdered
ash. Flame cutting torches can cut 2 feet deeper than wall/floor saws
and are also not impeded by reinforcing steel. The cutting torch or
lance is not consumed in this process and is thus reusable.

**Arc Saw** - An arc saw uses a smooth, rotating circular blade to pass
an electrical arc between the blade edge and a conductive material that
comes into close contact with it. The separation distance between the
cutting blade and the metal being cut is typically less than one inch.
As the material to be cut must be conductive, generally only metals may
be cut. The rotation of the blade (e.g., 350-1,800 RPM) aids in removing
molten metal and oxides from the kerf. Remote operability of these units
is available. Blade wear during cutting is estimated at a few percent of
the amount of metal that is removed from the kerf. Arc saws are not
portable and require a cutting table. In addition, power requirements
can be steep as a 36 in. diam. blade for cutting up to 12 in. thick
metals requires a power supply of 6,000 Amps.

**Plasma Arc Saw** - A plasma arc saw uses an inert gas such as argon
flowing through a constricting orifice to intensify an arc between an
electrode and any conductive material that comes into close contact with
it. The separation distance between the electrode and the metal being
cut is typically less than one inch. As the material to be cut must be
conductive, generally only metals may be cut. Remote operability of
these units is common, and portable hand-held units are available. A
plasma arc saw cutting head may be mounted on motor-driven rollers and
remotely driven over a section of metal to be cut. The power supply
requirements for plasma arc torches is somewhat less than arc saws as a
plasma arc torch with a 6 in. cutting ability would require an
electrical supply of 1,000 Amps.

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