ML12334A779
| ML12334A779 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 03/31/2011 |
| From: | Environmental Protection Agency |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| References | |
| RAS 21596, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 | |
| Download: ML12334A779 (3) | |
Text
March 2011 This document does not constitute nor should be construed as an EPA endorsement of any particular product, service, or technology.
Evaluation of Five Technologies for the Mechanical Removal of Radiological Contamination from Concrete Surfaces
Background
Because of its potential for deployment as a terrorist weapon in an urban setting, the radiological dispersion devise (RDD), the dirty bomb, is a very real and significant danger. The National Response Framework, the federal document that details how the nation responds to such threats, identifies the U.S.
Environmental Protection Agency (EPA) as a lead federal agency for decontamination following a radiological incident. This response to a radiological incident could include decontamination of buildings, equipment, and outdoor areas.
Thus, to support its designated role, EPAs National Homeland Security Research Center evaluated the performance of five mechanical decontamination tools for their ability to remove the radioactive isotope Cs-137 (Cesium-137) from the surface of unpainted concrete. In addition, NHSRC evaluated these tools for various deployment-related characteristics.
The work, completed in 2010, is described in a series of reports. These peer-reviewed reports provide rigorous evaluations of the efficacy of five commercially-available surface cleaning tools of the type that could be employed to decontaminate concrete surfaces following an RDD incident releasing Cs-137.These reports can be accessed via the NHSRC website (www.epa.gov/nhsrc/). The reports provide information that emergency responders can use in recommending or selecting appropriate technologies for use during cleanup operations. This information can also be used to assist federal, state, and local emergency management authorities and emergency response planners to prepare for radiological homeland security events.
Results A summary of the decontamination efficacy results is presented in Table 1. Unpainted concrete coupons (standardized samples) were contaminated with Cs-137 and the amount of contamination (radiological activity) deposited on each coupon was measured.
Each coupon was then treated with the decontamination technology under investigation As part of U. S. EPAs Office of Research and Development, the National Homeland Security Research Center (NHSRC) provides products and expertise to improve our nations ability to respond to environmental contamination caused by terrorist attacks on our nations water infrastructure, buildings and outdoor areas.
NHSRC conducts research related to:
Detecting and containing contamination from chemical, biological, and radiological agents
Assessing and mitigating exposure to contamination
Understanding the health effects of contamination
Developing risk-based exposure advisories
Decontaminating and disposing of contaminated materials.
United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of:
Entergy Nuclear Operations, Inc.
(Indian Point Nuclear Generating Units 2 and 3)
ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 l 05000286 Exhibit #:
Identified:
Admitted:
Withdrawn:
Rejected:
Stricken:
Other:
NYS000261-00-BD01 10/15/2012 10/15/2012 NYS000261 Submitted: December 21, 2011
March 2011 This document does not constitute nor should be construed as an EPA endorsement of any particular product, service, or technology.
and the amount of contamination was re-measured. The efficacy of the decontamination technology is expressed as percent of contamination removed (%R) and decontamination factor (DF). These efficacy measures are determined based on the following relationships:
%R = (1-Af/Ao) x 100%
DF = Ao/Af
%R = percent of contamination removed DF = decontamination factor Ao = radiological activity from the surface of the coupon before decontamination Af = radiological activity from the surface of the coupon after decontamination For each technology, the product name in Table 1 is hyperlinked to the corresponding report in the EPAs Science Inventory database. Deployment-related characteristics are presented in Table 2 grouped by type of technology (grinding vs. ablative).
Table 1. Decontamination Efficacy Product Technology Type Decontamination Efficacy
%R DF Dust Director with Wire Brush Grinding 38 7 1.6 0.2 Dust Director with Diamond Flap Wheel Grinding 89 8 14 8.5 CS Unitec Sander Grinding 54 10 2.3 0.07 River Technologies Rotating Water Jet Ablative 36 4 1.6 0.09 Empire Abrasive Blast nVac Ablative 96 3 41 21
%R, percent of contamination removed; DF, decontamination factor Table 2. Deployment Characteristics Parameter Grinding Technologies Ablative Technologies Decontamination Rate Approximately 1-3 m2/hr Approximately 5 m2/hr Applicability to irregular surfaces Irregularities kept some grinding heads from making good contact with the surface; the more aggressive the grinding head the greater the final contact area Very applicable as surface is receiving a pressurized blast of abrasive or water; ablative technologies are not dependent on the surface terrain Skilled labor requirement Brief training session adequate Brief training session adequate Utilities required 110V for both grinder and vacuum High pressure air compressor, hot water pressure washer Extent of portability Very portable Equipment requirements more significant, but hoses would likely allow access to most locations Setup time 30 minutes 2 days to assemble equipment, but once together setup would be minimal
March 2011 This document does not constitute nor should be construed as an EPA endorsement of any particular product, service, or technology.
Table 2. Deployment Characteristics (cont)
Parameter Grinding Technologies Ablative Technologies Secondary waste management Very little waste as vacuum very effective in dust collection Water spray during water blasting was difficult to contain and could cause contaminant re-aerosolization which would be a safety concern; grit blasting vacuum worked well Surface damage CSU Sander - minor visible surface damage DD Wire Brush - minor visible surface damage, discoloration of surface DD Diamond Flap Wheel - top 1-2 millimeters of coupon removed leaving exposed aggregate RT Rotating Water Jet - no visible surface damage EA Blast nVac 2 mm of coupon surface removed leaving exposed aggregate Technology Evaluation Reports Referenced Drake, J. 2011. CS Unitec ETR180 Circular Sander for Radiological Decontamination.
Technology Evaluation Report. Washington, D.C.: U.S. Environmental Protection Agency.
EPA/600/R-11/018.
Drake, J. 2011. Empire Abrasive Blast NVac for Radiological Decontamination. Technology Evaluation Report. Washington, D.C.: U.S. Environmental Protection Agency. EPA/600/R-11/014.
Drake, J. 2011. Industrial Contractors Supplies, Inc. Surface Dust Guard with Diamond Wheel for Radiological Decontamination. Technology Evaluation Report. Washington, D.C.: U.S.
Environmental Protection Agency. EPA/600/R-11/013.
Drake, J. 2011. Industrial Contractors Supplies, Inc. Surface Dust Guard with Wire Brush for Radiological Decontamination. Technology Evaluation Report. Washington, D.C.: U.S.
Environmental Protection Agency. EPA/600/R-11/016.
Drake, J. 2011. River Technologies LLC 3-Way Decontamination System for Radiological Decontamination. Technology Evaluation Report. Washington, D.C.: U.S. Environmental Protection Agency. EPA/600/R-11/015.
Contact Information For more information, visit the NHSRC Web site at www.epa.gov/nhsrc Technical
Contact:
John Drake (drake.john@epa.gov)
General Feedback/Questions: Kathy Nickel (nickel.kathy@epa.gov)