Decontamination concrete

ISOTRON s ELECTROSORB C technology applies an electric field to induce migration of ionic contaminants from within porous concrete. This process provides an in situ alternative to concrete decontamination, thereby eliminating physical or mechanical damage of the concrete and allowing reuse of the structure or facility. The process generates minimal secondary waste and no airborne particulates common to conventional scabbUng or physical abrasion techniques. 

Based on 1996 testing of the ELECTROSORB process for the U.S. Department of Energy (DOE), the vendor estimates the cost of concrete decontamination to be 4.91/ft. Costs square foot are broken down in the following manner disposal costs 2.51, capital costs 1.15, chemical costs 0.67, labor costs 0.52, vaporization energy 0,033, and electrical costs 0.03. This estimate is based on cleanup of 600 ft and involves the following components ... 

In September 1998, the U.S. Department of Energy (DOE) stated that, while the technology was not yet ready for industrial-scale concrete decontamination, the vendor believed that the necessary improvements to the system were relatively straightforward. 

In addition, a great deal of metal, concrete, decontamination solution, plastics, and spent activated carbon will be generated drrring the clostrre phase. 

Few new developments in concrete decontamination have taken place. Most equipment suppliers and developers have focused either on increasing productivity or improving means of controlling fugitive dust emissions. In situ reagent-based techniques have been applied in Europe, but not in the United States. (1)... 

Product ion/removal rates for some commonly used floor and wall concrete removal techniques are shown in Table 4. In general, the most productive techniques are also the crudest and generate the most waste Application of concrete decontamination in a relatively sensitive environment is easier to control but will typically require much slower production equipment such as that used in shot blasting. For heavy industrial applications with large floor spaces and limited impediments to movement, grinding or high pressure water techniques can be employed (Woodyard, 1985). 

Comparative effectiveness of selected cleaning techniques is shown in Table 5. When gauging the comparative success of these techniques on concrete, however, effectiveness alone is not a good evaluation criterion. Concrete decontamination situations typically involve surface cleaning or removal to a specified depth and are therefore not readily measured by percent removal of PCB. Proper characterization of the site is the key to the effectiveness of the removal technique, as it dictates what depth of removal is required. 

The potential for cross contamination exists during concrete decontamination, as many of the removal techniques are dusty or wet and therefore have a high potenial for contamination of other clean surfaces. As noted above, the slower, better controlled techniques, such as shot blasting, tend to minimize cross contamination while the cruder large surface techniques, such as grinding or hydroblasting, generate the most waste and the most airborne particulate/aerosol. 

More important, there is the potential for enhanced penetration during concrete decontamination if the appropriate techniques are not properly selected and applied. Haphoyard use of wet techniques in particular has been shown repeatedly to drive PCB contamination deeper into floors. In situations where surface sampling criteria are used to gauge effectiveness, this problem may go unnoticed and eventually result in contamination at lower depths. Wet techniques are to be avoided where possible for this reason. 

APPROXIMATE PRODUCTION RATES FOR SELECTED CONCRETE DECONTAMINATION TECHNIQUES... 

Barbier, M. M. and C. V. Chester, May 1980, Decontamination of Large Horizontal Surfaces Outdoors, presented at the USDOE Concrete Decontamination Workshop, Richland, Washington. 

Table III lists the major milestones of the JPDR dismantling activities. In parallel with dismantling the biological shield concrete, decontamination of the building inner surface has been started since the end of 1992. Various techniques such as steel blasting, and scabbier are applied to the decontamination work. After confirming that there is no...

Decontamination since concrete is a porous material it can absorb oil, rusty water, etc. and coatings can reduce the absorption. 

Decontamination Technologies, 20 Adjacent Sources of Contamination, 20 Concrete, 20... 

Recommendation 14. The Army should demonstrate that it has the ability to analyze for agents and their toxic degradation products in concrete, soil, and spent carbon, and to provide assurance that any structures or media left in place will be decontaminated consistent with the island s future use. 

The Decontamination Report provides an overall strategy for removing hazardous materials from the MDB, SWMUs, and AOls. A contamination investigation (RFI), yet to be completed, will provide the detailed characterization data to support closure activities. The characterizations will be based in part on analysis of concrete core borings taken from selected locations. 

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). 

The TechXtract process was used at a warehouse where PCB contamination resulted from the storage of electrical transformers. The decontamination costs for the concrete floor at this... 

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. 

Pentagone is an aqueous-based surface decontamination product developed for the cleanup of pentachlorophenols, creosote, petroleum hydrocarbons, chlorinated hydrocarbons, polynuclear aromatic hydrocarbons, and selected pesticide and herbicide spills. It can be used on concrete, asphalt, or metal and is capable of being applied as a foam, allowing treatment of overhead, vertical, and horizontal surfaces. It has been commercially available since 1993 and has been used in multiple applications. 

ISOTRON Corporation s electrokinetic decontamination process is a patented, in situ process for the removal of contaminants from soil, groundwater, and porous concrete. The technology applies a low-intensity direct current (DC) across electrode pairs to facilitate electromigration and electro-osmosis of contaminants. The process works primarily on highly soluble ionized inorganics including alkah metals, chlorides, nitrates, and phosphates. Heavy metals such as lead, mercury, cadmium, and chromium have also responded favorably. 

The technology is commercially available for the decontamination of soil and porous concrete but is still being developed for the decontamination of water. 

Cubic feet of waste per square foot of area decontaminated. This amount includes the generation of the above amount of removed concrete plus a 20% volume expansion factor. 

As part of the evaluation, a cost estimate of the centrifugal shot blast technology was prepared based on the demonstrated decontamination of 800 ft of concrete. The vendor provided personnel and equipment for which timed and measured activities were recorded to determine achievable production rates. These data included activity duration, work crew composition,... 

Ti02-coated glass, tiles, concrete, and polymers are being manufactured (7). The main purpose is to obtain self-cleaning materials (1,7,68). Some of them can also be used as decontaminating materials indoors when very weak ambient UV light needs to be counterbalanced by a large area covered by these materials (7). 

Matrices most used were soil, water, and organic liquids. Other matrices used were, for example, a polymer strip in the first proficiency test, a metal strip covered with a thin layer of paint in the third proficiency test, and a wipe sample in the fourth proficiency test. In the ninth and tenth proficiency tests, an emulsion sample and decontamination solutions were introduced. Not all sample matrices employed in the past are considered realistic. During the Preparatory Commission of the OPCW, the Task Force on Analytical Issues (see Fourth Report of the Expert Group on Inspection Procedures, PC-VIII/B/WP.12, dated September 20, 1994) discussed that sample matrices such as wipe, rubber, paint, and concrete will be extracted on site and sent as extracts off site for analysis, after splitting. 

During operational life these submarines are subject to periodic maintenance operations which can include refuelling. To undertake these operations, the submarine is taken into dry dock and supported on cradles which provide seismic stability. In addition to the dock gates further protection against flooding is provided by concrete caissons. Before any refuelling operations take place, the primary circuit is decontaminated and... 

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