Because there are literally square kilometers of radioactively contaminatedconcrete surfaces within the U.S. Department of Energy (DOE) complex, thetask (both scope and cost) of decontamination is staggering. Complex-widecleanup using conventional methodology does not appear to be feasible forevery facility because of prioritization, cost, and manual effortrequired.

We are investigating the feasibility of using microbially influenceddegradation (MID) of concrete as a unique, innovative approach for thedecontamination of concrete. Currently, work is being conducted to determinethe practicality and cost effectiveness of using this environmentallyacceptable method for decontamination of large surface concrete structures.Under laboratory conditions, the biodecontamination process has successfullybeen used to remove 2 mm of the surface of concrete slabs. Subsequently,initial field application data from an ongoing pilot-scale demonstrationhave shown that an average of 2 mm of surface can be removed frommeter-square areas of contaminated concrete. The cost for the process hasbeen estimated as $1.29/m2. Methodologies for field applicationof the process are being developed and will be tested. This paper providesinformation on the MID process, laboratory evaluation of its use fordecontamination, and results from the pilot field application.