Rotary Peening with Captive Shot at the Chicago Pile 5 Research Reactor, Argonne National Laboratory, Argonne, Illinois

Site Name:

Argonne National Laboratory

Location:

Argonne, Illinois

Period of
Operation:

1/28/97 to 2/4/97

Cleanup
Type:

Demonstration

Vendor:

Peter J. Fritz
Michael W. Lovejoy
3M Abrasive Systems Division
(612) 736-3655/(612) 733-7181

West Environmental
Pentek, Inc
EDCO

Technology:
Rotary Peening with Captive Shot:
- 3M Heavy Duty Roto Peen (HDRP) flaps supporting tungsten carbide shot mounted on a rotating hub
- EDCO CPM-4 concrete planer - cutting width of 5.5 inches and capable of rotating the Roto Peen at 1,800 rpm
- Pentek VAC-PAC® model 24 vacuum system - 600 ft3/min; primary roughing filter cartridges with 95% efficiency at 1 micron; secondary HEPA filter with 99.97% efficiency at 0.3 micron
- Pb Sentry vacuum monitor (for vacuum pressure)

Cleanup Authority:
Project performed as part of DOE's Large-Scale Demonstration Project, Office of Science and Technology, Deactivation and Decommissioning Focus Area

Regulatory Point of Contact:
Information not provided
Additional Contacts:
Ed Wiese
Cedric Andres
Argonne National Laboratory
(630) 252-2000

Contaminants:
Radioactive-contaminated paint

Waste Source:
Radioactive-contaminated paint coating on concrete floor

Type/Quantity of Media Treated:
Radioactively contaminated concrete floor - 425 ft2 of concrete flooring covered with contaminated paint

Purpose/Significance of Application:
Demonstrate Rotary Peening with captive shot and compare results with those for mechanical scabbing

Regulatory Requirements/Cleanup Goals:
The objective of the demonstration was to evaluate the performance of Rotary Peening with Captive Shot to remove contaminated paint coating from 425 ft2 of concrete flooring and to compare the results of this technology with those from the baseline technology of mechanical scabbing.

Results:
- Reduced radiological levels in 5 of 6 areas tested to below background levels. For one location, levels were reduced from 70,000 to 16,000 dpm/100 cm2. A possible reason for the remaining radioactivity was a crack in the floor that trapped contamination (could not be removed superficially).
- Removed paint coatings at a rate of 71 ft2/hr with a two-person crew and a 5.5-inch cutting width.
- Vacuum system performed sufficiently to maintain airborne radioactivity levels at background levels.
- Removed floor's paint coating with minimal concrete removal, resulting in minimal waste generation.
- The main advantage of the modified centrifugal shot blast system over the baseline technology is the ability to simultaneously collect dust and debris using a dust collection system attached to the shot blast unit.

Cost Factors:
- The report presents a detailed cost analysis of this technology compared to the baseline technology.
- Cost analysis results show the total cost for Roto Peen with captive shot was 50% lower than the baseline of mechanical scabbing (about $4,500 versus about $9,500). The major contributor to the savings was that the Roto Peen with captive shot blast did not require a temporary enclosure (about $2,400).

Description:
3M's Rotary Peening with Captive Shot system was demonstrated at the Chicago Pile 5 (CP-5) Research Reactor at Argonne National Laboratory. This demonstration was part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project sponsored by DOE, Office of Science and Technology, Deactivation and Decommissioning Focus Area, to demonstrate the benefits of using innovative and improved decontamination and decommissioning technologies. CP-5 was a heavy-water moderated and cooled, highly enriched, uranium-fueled thermal reactor designed to supply neutrons for research and was operated for 25 years before being shut down in 1979.

The 3M Heavy Duty Roto Peen (HDRP) flap consists of tungsten carbide shot attached to a flexible, heavy duty material and mounted on an aluminum rotating hub. As the hub rotates, the shot particles on each flap impact against the surface and mechanically fracture and remove coatings. A concrete planer (EDCO Model CPM-4), used to drive the Roto Peen, had a cutting width of 5.5 inches and was capable of rotating the Roto Peen at 1,800 rpm. The dust collection system was a Pentek VAC-PAC® model 24 vacuum system. A Pb Sentry vacuum monitor (proprietary design by West Environmental) was used to interrupt the electrical supply to the concrete planer when a variation in vacuum pressure at the CPM-4 was detected. The demonstration showed that the main advantage of the Roto Peen with captive shot technology compared to mechanical scabbing was the simultaneous collection of dust and debris. The report includes a detailed comparison of the two technologies. In addition, the Roto Peen technology reduced radiological levels to below background levels in all but one area. For one location, levels were reduced from 70,000 to 16,000 dpm/100 cm2. The elevated readings were attributed to a possible crack in the floor which trapped contamination and could not be removed superficially. The technology removed paint coatings at a rate of 71 ft2/hr, and removed floor's paint coating with minimal concrete removal, resulting in minimal waste generation.

The report includes results of a detailed cost analysis comparing the centrifugal shot blast technology with mechanical scabbing. Cost analysis results show that the total cost for Roto Peen with captive shot was 50% lower than the baseline of mechanical scabbing. The major contributor to the savings was that the Roto Peen with captive shot blast did not require a temporary enclosure.