Surface decontamination coatings

CORPEX Technologies, Inc., offers CORPEX technology for the decontamination of undesirable and toxic ions or radionuclides from contaminated surfaces and coatings. The vendor states that the process can operate as either a batch or semicontinuous process. The commercially available CORPEX technology uses patented, innovative chelation chemicals to control and recover radioactive and other types of hazardous metal ions from soils, concrete, steel, and other materials. 

Photocatalytic bactericidal activity experiments were performed using E. coli with untreated and TiO -coated fabric and aluminum foil (Fig. 1.6) and with or without UV-A irradiation. Photocatalytic bactericidal properties of TiO -coated fabric and foil were observed after 30 min. The most distinctive difference between coated and UV-irradiated materials was observed initially. This is a clear demonstration of the photocatalytic ability of TiO and accelerated surface decontamination. We observed complete bacteria killing only on aluminum foil coated with TiO, and partial killing on the coated fabric. These results suggest that TiO coated materials have bactericidal properties. 

In chemical munitions facilities, surfaces must be sealed by coating or treating to prevent agent absorption during spills so that decontamination can be obtained. 

The MDB is a two-story, steel-framed building with thick, reinforced-concrete floors and most interior walls made of concrete and foam-core sandwich panels. Explosion containment rooms have 2-foot-thick reinforced concrete floors, walls, and ceilings. Because concrete is a porous material capable of absorbing agent, all concrete surfaces in the JACADS process areas were sealed with an epoxy coating. A total of 134,153 square feet of concrete will require decontamination (U.S. Army, 1999d). 

PTE was also entrapped in additives for latex coating of biodefensive surfaces. Such PTE-based additives for paints and coatings were shown to retain catalytic parameters and stability of the enzyme (McDaniel et al, 2006). For decontamination of OPs in the environment and remediation, an alternative approach, phytodegradation by transgenic plants (e.g. tobacco) expressing a bacterial PTE, has been considered as a potentially low-cost, effective, and environmentally friendly method (Wang et al, 2008). 

Nuclear coatings are formulated to seal and protect concrete, concrete block and steel surfaces. The most commonly used coating types are the amine and polyamide cured epoxy systems. The solids, by volume, can vary from 50 to 100% with fillers or reinforcement fibers usually added so that the coating can perform a wide variety of functions. Reasons for their wide use are that they bond tenaciously to a variety of substrates they cure to a hard smooth finish which results in superior decontamination qualities and, most importantly, they perform satisfactorily in Ciass 1 and 2 service. 

Since Class 1 and 2 surfaces must be easily decontaminated to safe levels, these imperfections must be corrected. The offsets, fins and projections are usually repaired by masons using stones and grinding wheels. The blowholes are corrected by application of the coating materials. 

From about ten meters down to the close-off depth it is necessary to use electromechanical drilling systems (31) to collect samples. The outside surface of cores collected in this way can often be contaminated by heavy metals because of the contact between the drill body and the snow or ice core itself. This fact can be minimized by using special devices, such as plastic coated drills, and by carefully manipulating samples. In any case, it is necessary to proceed to a decontamination of the cores because the outer layer can be heavily contaminated (see below) this operation is usually feasible because the high density of the firn or ice prevents transfer of contaminating metals to the inner part of the sample section. 

KMn04 include the surface treatment of carbon steels and stainless steels (descaling and desmutting), electrode coating of welding rods and decontamination of nuclear reactors (Reidies 2003). 

Materials of construction should be smooth and nonporous, nonionic irx nature, with good chemical and heat-resistant properties. A listing of materials in order of increasing difficulty of decontamination includes (1) polyethylene, (2) glass, (3) stainless steel, (4) copper,.(5) brass, (6) carbon steel, (7) lead, and (8) concrete. Nearly 100 per cent of the applied activity is adsorbed on a porous material such as concrete and cannot be removed. Special plastic paints and coatings which can be applied to rough surfaces and subsequently peeled off when contaminated have proved useful in building construction. 

The decontamination is accomplished by merely opening the packet and scrubbing the skin surface with the applicator pad until an even coating of the resin is achieved. Use normal precautions to keep the powder from wounds, the eyes, and the mouth. The M291 kit is also used for training. 

Rapid, contamination indicator, e.g., nanowires, transistors, with potential to transmit information Decontaminating Precoat Surface coatings that encapsulate an agent and can be removed chemically or catalyticaUy to be decontaminated at later stage... 

The corrosion protection of the HMMWV was to be provided by the military coating specification Mil-C-46164 and the CARC. The CARC paint system consists of a surface cleaning, epoxy primer, epoxy interior topcoat, and a polyurethane exterior topcoat. The purpose of this coating was to provide chemical resistance (penetration of the coating) and to aid in the decontamination of the vehicle in case of chemical attack. The coating was to provide corrosion protection as well as... 

Various surface effects can be produced by varying the viscosity and adding coarse, possibly colored extenders or fibers. Two-pack systems based on polyurethane resins or epoxy resins are used for wall coatings that require a good resistance to agents used for chemical cleaning and decontamination. 

Smooth and Coat Concrete SurfacRc - These are preventive and protective measures against the radioactive contamination of concrete surfaces and thus decrease the quantity of radwaste associated with the decontamination of such surfaces. 

In the case of OP decontamination, parathion and paraoxon were spin-coated on glass or gold film surfaces from 0.023 ttiM solution in ethanol. The loadings of parathion and paraoxon were determined with a quartz crystal microbalance (QCM). The deposited amount of parathion and paraoxon film was 8.5 pg/cm and 5.0 pg/cm, respectively. These OP films were then treated with an 02/Ar plasma. The treated samples were analyzed with polarization-modulcation reflection absorption infrared spectroscopy (PM-RAIRS Thermo Nicholet Nexus 670 with a Hindz polarization modulation imit and a GWC demodulator) and tested for residual toxicity. 

The outer surfaces of the cask, as well as primary and secondary lid are provided with a multi-coated decontaminable paint. The inner cavity is protected with a zinc-silicate coating. The trunnions are protected with a zinc-coating. 

The coatings of fuel storage ponds and fuel handling ponds, as well as the equipment used in these areas, will become contaminated. When the water level in such ponds is lowered, surfaces may dry out, and this may cause a hazard due to airborne radioactive material. Systems should be provided for decontaminating such surfaces before they dry out. Systems should also be provided for decontaminating, before they dry out, fuel transport flasks and components that may have to be removed from the ponds for repair. 

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