ML12090A817
| ML12090A817 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 06/30/2011 |
| From: | Environmental Protection Agency |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| Shared Package | |
| ML12090A808 | List: |
| References | |
| RAS 22160, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 EPA 600/R-11/083 | |
| Download: ML12090A817 (30) | |
Text
ENT000473 Submitted: March 30, 2012 EPA 600/R-11/083 l August 2011 l www.epa.gov/ord Technology Evaluation Report Environmental Alternatives, Inc.
Rad-Release I and II for Radiological Decontamination Of"ce of Research and Development National Homeland Security Research Center
EPA 600/R-11/083 June 2011 Technology Evaluation Report Environmental Alternatives, Inc.
Rad-Release I and II for Radiological Decontamination John Drake Task Order Project Officer National Homeland Security Research Center Office of Research and Development U.S. Environmental Protection Agency 26 Martin Luther King Drive Cincinnati, OH 45268
Disclaimer The U.S. Environmental Protection Agency (EPA), through its Office of Research and Developments National Homeland Security Research Center, funded and managed this technology evaluation through a Blanket Purchase Agreement under General Services Administration contract number GS23F0011L-3 with Battelle. This report has been peer and administratively reviewed and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use of a specific product.
Questions concerning this document or its application should be addressed to:
John Drake National Homeland Security Research Center Office of Research and Development U.S. Environmental Protection Agency 26 West Martin Luther King Dr.
Cincinnati, OH 45268 513-569-7164 drake.john@epa.gov
Foreword The Environmental Protection Agency (EPA) holds responsibilities associated with homeland security events: EPA is the primary federal agency responsible for decontamination following a chemical, biological, and/or radiological (CBR) attack. The National Homeland Security Research Center (NHSRC) was established to conduct research and deliver scientific products that improve the capability of the Agency to carry out these responsibilities.
An important goal of NHSRCs research is to develop and deliver information on decontamination methods and technologies to clean up CBR contamination. When directing such a recovery operation, EPA and other stakeholders must identify and implement decontamination technologies that are appropriate for the given situation. The NHSRC has created the Technology Testing and Evaluation Program (TTEP) in an effort to provide reliable information regarding the performance of homeland security related technologies. Through TTEP, NHSRC provides independent, quality assured performance information that is useful to decision makers in purchasing or applying the tested technologies. TTEP provides potential users with unbiased, third-party information that can supplement vendor-provided information. Stakeholder involvement ensures that user needs and perspectives are incorporated into the test design so that useful performance information is produced for each of the tested technologies. The technology categories of interest include detection and monitoring, water treatment, air purification, decontamination, and computer modeling tools for use by those responsible for protecting buildings, drinking water supplies and infrastructure, and for decontaminating structures and the outdoor environment. Additionally, environmental persistence information is also important for containment and decontamination decisions.
NHSRC is pleased to make this publication available to assist the response community to prepare for and recover from disasters involving CBR contamination. This research is intended to move EPA one step closer to achieving its homeland security goals and its overall mission of protecting human health and the environment while providing sustainable solutions to our environmental problems.
Jonathan G. Herrmann, Director National Homeland Security Research Center ii
Acknowledgments Contributions of the following individuals and organizations to the development of this document are gratefully acknowledged.
United States Environmental Protection Agency (EPA)
John Drake Emily Snyder Sang Don Lee Eletha Brady-Roberts Scott Hudson Alyssa Hughes University of Tennessee Dr. Howard Hall United States Department of Energys Idaho National Laboratories Battelle Memorial Institute iii
Contents Disclaimer ........................................................................................................................... .i Foreword ............................................................................................................................ .ii Acknowledgments.............................................................................................................. iii Abbreviations/Acronyms .................................................................................................. vii Executive Summary ......................................................................................................... viii 1.0 Introduction...................................................................................................................1 2.0 Technology Description................................................................................................3 3.0 Experimental Details.....................................................................................................5 3.1 Experiment Preparation......................................................................................5 3.1.1 Concrete Coupons ..................................................................................5 3.1.2 Coupon Contamination...........................................................................6 3.1.3 Measurement of Activity on Coupon Surface ........................................7 3.1.4 Surface Construction Using Test Stand..................................................7 3.2 Evaluation Procedures........................................................................................8 4.0 Quality Assurance/Quality Control.............................................................................10 4.1 Intrinsic Germanium Detector..........................................................................10 4.2 Audits ...............................................................................................................11 4.2.1 Performance Evaluation Audit .............................................................11 4.2.2 Technical Systems Audit......................................................................11 4.2.3 Data Quality Audit ...............................................................................12 4.3 QA/QC Reporting.............................................................................................12 5.0 Evaluation Results ......................................................................................................13 5.1 Decontamination Efficacy................................................................................13 5.2 Deployment and Operational Factors...............................................................15 6.0 Performance Summary................................................................................................18 6.1 Decontamination Efficacy................................................................................18 6.2 Deployment and Operational Factors...............................................................18 7.0 References...................................................................................................................19 iv
Figures Figure 2-1. Rad-Release container (right) and spray bottle applicator (left)................... 4 Figure 3-1. Demonstration of contaminant application technique. ................................. 6 Figure 3-2. Containment tent: outer view (left) and inner view with test stand containing contaminated coupons (right)...................................................... 7 Figure 5-1. Rinsing and vacuuming Rad-Release from concrete coupon. .................... 16 Tables Table 3-1. Characteristics of Portland Cement Clinker Used to Make Concrete Coupons ......................................................................................................... 5 Table 4-1. Calibration Results - Difference from Th-228 Calibration Energies .......... 10 Table 4-2. NIST-Traceable Eu-152 Activity Standard Check ...................................... 11 Table 5-1. Decontamination Efficacy Results for Rad-Release I ................................. 14 Table 5-2. Decontamination Efficacy Results for Rad-Release II ................................ 14 Table 5-3. Operational Factors Gathered from the Evaluation ..................................... 17 v
Abbreviations/Acronyms ANSI American National Standards Institute ASTM ASTM International BQ Becquerel CBRNIAC Chemical, Biological, Radiological, Nuclear Defense Information Analysis Center
°C degrees Celsius CC cross-contamination CFR Code of Federal Regulations Cs cesium cm centimeter cm2 square centimeter DARPA Defense Advanced Research Projects Agency DF decontamination factor DHS U.S. Department of Homeland Security DOD Department of Defense EAI Environmental Alternatives, Inc.
EPA U.S. Environmental Protection Agency Eu Europium
°F degrees Fahrenheit IEEE Institute of Electrical and Electronics Engineers INL Idaho National Laboratory keV kilo electron volts mL milliliter(s)
L liter m meter m2 square meter
µCi microCurie NHSRC National Homeland Security Research Center NIST National Institute of Standards and Technology ORD Office of Research and Development PE performance evaluation PPE personal protective equipment
%R percent removal QA quality assurance QC quality control QMP quality management plan RDD radiological dispersion device RH relative humidity RML Radiological Measurement Laboratory RSD relative standard deviation TCLP Toxicity Characteristic Leaching Procedure Th thorium TSA technical systems audit TTEP Technology Testing and Evaluation Program vi
Executive Summary The U.S. Environmental Protection Agencys (EPA) National Homeland Security Research Center (NHSRC) is helping to protect human health and the environment from adverse impacts resulting from acts of terror by carrying out performance tests on homeland security technologies. Through its Technology Testing and Evaluation Program (TTEP), NHSRC evaluated the Environmental Alternatives Inc. (EAI) Rad-Release I and Rad-Release II and their ability to remove radioactive cesium (Cs)-137 from the surface of unpainted concrete.
Experimental Procedures. The Rad-Release I decontamination technology is a chemical process that involves the topical application of a single decontamination solution to treat various substrates bearing radiological contamination. Rad-Release II is a similar chemical process that involves the topical application of two solutions. Eight 15 centimeter (cm) x 15 cm unpainted concrete coupons were contaminated with approximately 1 microCurie (µCi) of Cs-137 per coupon. The amount of contamination deposited on each coupon was measured using gamma spectroscopy. The eight contaminated coupons were placed in a test stand (along with one uncontaminated blank coupon) that was designed to hold nine concrete coupons in a vertical orientation to simulate the wall of a building. Four coupons were decontaminated with Rad-Release I and four with Rad-Release II. The one-step Rad-Release I included application of a spray, a 30 minute dwell time, rinse, and removal. Rad-Release II included two formulations which followed the same procedure as Rad-Release I. The decontamination efficacy was determined by calculating both a decontamination factor (DF) and percent removal (%R). Important deployment and operational factors were also documented and reported.
Results. The decontamination efficacy (in terms of %R) attained for Rad-Release I and Rad-Release II was evaluated for each concrete coupon used during the evaluation. When the decontamination efficacy metrics (%R and DF) of the four contaminated coupons decontaminated by each were averaged together, the average %R for Rad-Release I was 71% +/- 13% and the average DF was 3.9 +/- 1.5. The average %R for Rad-Release II was 85% +/- 2% and the average DF was 7.0 +/- 1.1.
The application of Rad-Release I and Rad-Release II was performed using plastic spray bottles. For Rad-Release I, the concrete coupons were thoroughly wetted with Rad-Release I with 3-4 sprays. Then, the solution was worked into the surface of the coupon by scrubbing the entire surface of the coupon once with a scouring pad. During this evaluation, the initial application of Rad-Release I took only 10-15 seconds for each coupon. The next step was a 30 minute dwell time for the Rad-Release I to reside on the surfaces of the concrete coupons. After 30 minutes, the surface of the concrete coupons were thoroughly wetted with a deionized water/10% nitric acid rinse solution using another spray bottle and then the sprayed material was removed with a wet vacuum vii
(vacuuming took about one minute per coupon). Rad-Release II was used in the same way but there were two formulations that went through the process described above.
Therefore, the Rad-Release I application took approximately 37 minutes and the Rad-Release II application took approximately 65 minutes because the dwell times were the major factor in the application time.
The waste generated through use of Rad-Release I and Rad-Release II was estimated to be approximately 7 liters (L)/ square meter (m2). As used for this evaluation, only the wet vacuum required electricity. Scaled up applications in remote locations may require additional utilities to provide means for sprayer or foamer application and vacuum removal. Minimal training would be required for technicians using Rad-Release I and Rad-Release II, and the surface of the concrete was not visibly damaged during use.
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1.0 Introduction The U.S. Environmental Protection are defensible. Through TTEP, NHSRC Agencys (EPA) National Homeland provides high-quality information that is Security Research Center (NHSRC) is useful to decision makers in purchasing helping to protect human health and the or applying the evaluated technologies, environment from adverse effects and in planning cleanup operations. The resulting from acts of terror. NHSRC is evaluations generated through TTEP emphasizing decontamination and provide potential users with unbiased, consequence management, water third-party information that can infrastructure protection, and threat and supplement vendor-provided consequence assessment. In doing so, information. Stakeholder involvement NHRSC is working to develop tools and ensures that user needs and perspectives information that will improve the ability are incorporated into the evaluation of operational personnel to detect the design so that useful performance intentional introduction of chemical, information is produced for each of the biological, or radiological contaminants evaluated technologies.
on or into buildings or water systems, to contain or mitigate these contaminants, Under TTEP, NHSRC evaluated the to decontaminate affected buildings performance of two technologies from and/or water systems, and to dispose of Environmental Alternatives, Inc. (EAI) contaminated materials resulting from (Keene, NH), Rad-Release I and Rad-clean-ups. Release II, in removing radioactive isotope cesium (Cs)-137 from unpainted NHSRCs Technology Testing and concrete. A peer-reviewed test/QA plan Evaluation Program (TTEP) works in was followed, entitled The Performance partnership with recognized testing of Selected Radiological organizations; stakeholder groups Decontamination Processes on Urban consisting of buyers, vendor Substrates, Version 1.0, Amendment 1 organizations, and permitters; and dated July 14, 2010. This document will through the participation of individual be referred to as the test/QA plan and technology developers in carrying out was developed according to the performance tests on homeland security requirements of the Quality Management technologies. The program evaluates the Plan (QMP) for the Technology Testing performance of homeland security and Evaluation Program, Version 3.0 technologies by developing evaluation dated January 2008. The evaluation plans that are responsive to the needs of generated the following performance stakeholders, conducting tests, collecting information:
and analyzing data, and preparing peer-
- Decontamination efficacy, reviewed reports. All evaluations are defined as the extent of conducted in accordance with rigorous radionuclide removal following quality assurance (QA) protocols to use of Rad-Release I and Rad-ensure that data of known and high Release II, and the possibility of quality are generated and that the results cross-contamination (CC) 1
- Deployment and operational measurements occurring in early factors, including the November 2010. All of the experimental approximate rate of surface area work took place in a radiological decontamination, applicability to contamination area at the U.S.
irregular surfaces, skilled labor Department of Energys Idaho National requirement, utility requirements, Laboratory (INL). This report describes portability, secondary waste the quantitative results and qualitative management, and technology observations gathered during the cost. evaluation of the Rad-Release I and Rad-Release II. The contractor and EPA The evaluation of Rad-Release I and were responsible for QA oversight. A Rad-Release II took place October 27, technical systems audit (TSA) was 2010, with the pre-evaluation activity conducted during the evaluation as well measurements occurring in September as a data quality audit of the evaluation 2010 and the post-evaluation activity data.
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2.0 Technology Description This technology evaluation report application are tailored to the specific provides results on the performance of substrate, targeted contaminant(s), and Rad-Release I and Rad-Release II under surface interferences. The Rad-Release I laboratory conditions. The following solution contains salts to promote ion description of Rad-Release I and Rad- exchange and surfactants to remove dirt, Release II is based on information oil, grease, and other surface provided by the vendor and was not interferences. Broad-target and target-verified during this evaluation. specific chelants are blended into the solution to sequester and encapsulate the The Rad-Release I decontamination contaminants, keeping them in technology is a chemical process that suspension until they are removed by the involves the topical application of a subsequent rinse. Rad-Release II single decontamination solution to treat includes one solution that is chemically various substrates bearing radiological similar to Rad-Release I and serves the contamination. Rad-Release II is a same purpose in decontamination similar chemical process that involves (although it is not the same solution).
the sequential topical application of two Rad-Release II includes a second solutions (applied in the order directed solution designed as a caustic solution by EAI). Both Rad-Release containing salts to promote ion technologies extract radionuclides, exchange, ionic and nonionic including transuranics, from nearly all surfactants, and additional sequestering substrates. This process was developed agents, also utilized to encapsulate the to be used in sequence to synergistically contaminants and keep them in remove the contaminants via the suspension until they are removed by the migration pathways, pores and subsequent rinse.
capillaries of the contaminated material.
Both Rad-Release I and Rad-Release II Rad-Release I and II are effective for are applied in low volumes, as either an both loose surface and fixed subsurface atomized spray or foam. Foam contamination and situations in which deployment of the solution is most the contamination is a mixture of pure appropriate for large scale applications elements, oxides, and related compounds while the spray application (as used with varying solubility indices. during this evaluation) is beneficial for Substrates for which Rad-Release I and smaller applications and applications II can be used include those that are both where waste minimization is a critical porous and seemingly nonporous. Both factor. After the decontamination technologies can be deployed on various solution is applied, light mechanical geometries including walls, ceilings, action (e.g., a light scrubbing or equipment, structural beams, internal brushing with a scouring pad) is applied piping and highly irregular surfaces. to ensure good contact with the contaminated surface. The solution is To maximize the efficacy of the then left to reside for 30 minutes extraction process, the chemistry and followed by a rinse and removal.
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Several options are available to facilitate Section 261 (40CFR 261)) and has no the removal step (e.g., vacuuming, components that would be classified as simple wiping with absorbent laboratory hazardous for disposal under Toxicity wipes or rags for small surfaces, use of a Characteristic Leaching Procedure clay overlay technique to wick out the (TCLP) testing. As a result, the waste Rad-Release and contamination over stream from a project can be time and then remove the clay at a later characterized based on the contaminants date, or use of an absorbent polymer that that were removed. Liquid waste is sprayed over the chemically treated volumes are usually 400 mL/square surface to leach or wick out the meter (m2) to 4000 mL/m2 of contaminant laden solutions and bind contaminated substrate. Depending on them up). The sequence of application, the matrix and the amount of rinse dwell, rinse, and removal of the applied, the liquid waste stream may decontamination solution constitutes a have a resultant pH of less than 2. A pH single iteration. This procedure may be neutral waste can be attained by repeated, as needed, until the desired stoichiometrically adding sodium residual contaminant levels are achieved. bicarbonate or another neutralizing agent. Waste may be handled by The blended solution contains no solidification, incineration, discharged to hazardous components regarding liquid effluent treatment systems, and/or flammability or reactivity (as per Title evaporation. More information is 40 of the Code of Federal Regulations available at www.eai-inc.com.
Figure 2-1. Rad-Release container (right) and spray bottle applicator (left).
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3.0 Experimental Details 3.1 Experiment Preparation cement clinker (by weight). The cement 3.1.1 Concrete Coupons clinker used for the concrete coupons The concrete coupons were prepared was 4.5% tricalcium aluminate (Table 3 from a single batch of concrete made 1). For Type I Portland cement the from Type II Portland cement. The tricalcium aluminate content should be ready-mix company (Burns Brothers less than 15%. Because Type I and II Redi-Mix, Idaho Falls, ID) that supplied Portland cements differ only in the concrete for this evaluation provided tricalcium aluminate content, the cement the data which describe the cement used during this evaluation meets the clinker used in the concrete mix. For specifications for both Type I and II Type II Portland cement, the ASTM Portland cements. The apparent porosity International (ASTM) Standard C 150-71 of the concrete from the prepared specifies that tricalcium aluminate coupons ranged from 15-30%.
accounts for less than 8% of the overall Table 3-1. Characteristics of Portland Cement Clinker Used to Make Concrete Coupons Cement Constituent Percent of Mixture Tricalcium Silicate 57.6 Dicalcium Silicate 21.1 Tricalcium Aluminate 4.5 Tetracalcium Aluminoferrite 8.7 Minor Constituents 8.1 The concrete was representative of curing, the squares were cut to the exterior concrete commonly found in desired size with a laser-guided rock urban environments in the United States saw. For this evaluation, the floated as shown by INL under a previous surface of the concrete coupons was project entitled, Radionuclide Detection used. The coupons were approximately and Decontamination Program. Broad 4 centimeters (cm) thick, 15 cm x 15 cm Agency Announcement 03-013 square, and had a surface finish that was sponsored by the U.S. Department of consistent across all the coupons. No Defense (DOD), Defense Advanced further weathering, conditioning, or Research Projects Agency (DARPA) and treatment was performed on these U.S. Department of Homeland Security concrete coupons.
(DHS). The wet concrete was poured into 0.9 meter (m) square plywood forms with the exposed surface floated to allow the smaller aggregate and cement paste to float to the top, and the concrete was then cured for 21 days. Following 5
3.1.2 Coupon Contamination compressed air line was attached to the Eight coupons were contaminated by rear of the syringe. The second syringe spiking individually with 2.5 milliliters contained the contaminant solution and (mL) of aqueous solution that contained was equipped with a 27 gauge needle, 0.4 microCurie (µCi)/mL Cs-137 as a which penetrated through the plastic solution of cesium chloride, housing near the tip of the first syringe.
corresponding to an activity level of Compressed air flowing at a rate of approximately 1 µCi over the 225 square approximately 1 - 2 liter (L) per minute centimeters (cm2) surface. Application created a turbulent flow through the first of the Cs-137 in an aqueous solution was syringe. When the contaminant solution justified because even if Cs-137 were in the second syringe was introduced, it dispersed in a particle form following a became nebulized by the turbulent air radiological dispersion device (RDD) or flow. A fine aerosol was ejected from dirty bomb event, morning dew or the tip of the first syringe, creating a rainfall would likely occur before the controlled and uniform spray of fine surfaces could be decontaminated. In liquid droplets onto the coupon surface.
addition, from an experimental The contaminant spray was applied all standpoint, it is much easier to apply the way to the edges of the coupon, liquids, rather than particles, which were taped (after having homogeneously across the surface of the previously been sealed with polyester concrete coupons. The liquid spike was resin) to ensure that the contaminant was delivered to each coupon using an applied only to the surfaces of the aerosolization technique developed by coupons. The photographs in Figure 3-1 INL (under a DARPA/DHS project). show this procedure being performed using a nonradioactive, nonhazardous The aerosol delivery device was aqueous dye to demonstrate that the 2.5 constructed of two syringes. The plunger mL of contaminant solution is and needle were removed from the first effectively distributed across the surface syringe and discarded. Then a of the coupon.
Figure 3-1. Demonstration of contaminant application technique.
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3.1.3 Measurement of Activity on was employed and certified results were Coupon Surface provided.
Gamma radiation from the surface of each concrete coupon was measured to 3.1.4 Surface Construction Using Test quantify contamination levels both Stand before and after evaluation of Rad- To evaluate the decontamination Release I and Rad-Release II. These technologies on vertical surfaces measurements were made using an (simulating walls), a stainless steel test intrinsic, high purity germanium detector stand that held three rows of three (Canberra LEGe Model GL 2825R/S, concrete coupons was used. The test Meriden, CT). After being placed in the stand, approximately 2.7 m x 2.7 m, was detector, each coupon was measured erected within a containment tent. The until the average activity level of Cs-137 concrete coupons were placed into from the surface stabilized to a relative holders so their surfaces extended just standard deviation (RSD) of less than beyond the surface of the stainless steel 2%. Gamma-ray spectra acquired from face of the test stand. Eight of the nine Cs-137 contaminated coupons were coupons placed in the test stand were analyzed using INL Radiological contaminated with Cs-137, which has a Measurement Laboratory (RML) data half-life of 30 years. One acquisition and spectral analysis uncontaminated coupon was placed in programs. Radionuclide activities on the bottom row of the test stand (position coupons were calculated based on 8) and decontaminated in the same way efficiency, emission probability, and as the other coupons. This coupon, half-life values. Decay corrections were referred to as the CC blank, was placed made based on the date and the duration there to observe possible CC caused by of the counting period. Full RML the decontamination higher on the wall.
gamma counting QA/quality control Figure 3-2 shows the containment tent (QC), as described in the test/QA plan, and the test stand loaded with the concrete coupons.
1 2 3 4 5 6 7 8 9 Figure 3-2. Containment tent: outer view (left) and inner view with test stand containing contaminated coupons with numbered coupon positions (right).
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3.2 Evaluation Procedures solutions to the contaminated matrix, as The nine concrete coupons in the test would be observed when deployed as a stand which had been contaminated foam for larger scale real-world approximately one month before were applications. After 30 minutes, the decontaminated using Rad-Release I and surface of the concrete coupons were Rad-Release II. Rad-Release I was thoroughly wetted with a deionized applied to the coupons in positions 3, 5, water/10% nitric acid rinse solution 6, 8 (blank coupon), and 9 while Rad- using another spray bottle and then the Release II was used on the coupons in solution sprayed on the surface was positions 1, 2, 4, and 7. Both Rad- removed with a wet vacuum (12 gallon, Release I and Rad-Release II were 4.5 horsepower, QSP Quiet Deluxe, applied in the order given above to Shop-Vac Corporation, Williamsport, simulate an approach that would likely VA) which took about one minute per be taken in an actual decontamination coupon. The overall decontamination event, where higher wall surfaces would method for Rad-Release I included:
be decontaminated first because of the 1. Apply Rad-Release I with spray possibility of secondary contamination bottle lower on the wall. 2. Scrub surface with scouring pad
- 3. Wait 30 minutes, during which The application of Rad-Release I and the surface is kept wet with Rad-Release II was performed using additional sprays every 5 minutes plastic spray bottles (32 oz. Heavy Duty (to simulate foam collapse)
Spray Bottle, Rubbermaid Professional, 4. Thoroughly wet with deionized Atlanta, GA). For Rad-Release I, the water/10% nitric acid rinse concrete coupons were thoroughly solution wetted with Rad-Release I with 3 - 4 5. Remove with wet vacuum by sprays. Then, the solution was worked moving over the surface one time into the surface of the coupon by with the open end of a 1 1/4 inch scrubbing the entire surface of the hose flat against the surface coupon once with a scouring pad (Heavy without an attachment.
Duty Scouring Pad, 3M Scotch-Brite, St.
Paul, MN). During this evaluation, the The application of Rad-Release II was a initial application of Rad-Release I took two-step application done using the only 10-15 seconds for each coupon. same steps as described above for Rad-The next step was a 30 minute dwell Release I. The above procedure was time for the Rad-Release I to reside on followed for Rad-Release II, Solution 1.
the surfaces of the concrete coupons. Then, the same procedure was repeated The coupon surfaces were kept damp for Rad-Release II, Solution 2.
with 1-2 sprays of additional Rad- Therefore, the Rad-Release I procedure Release I approximately every five took approximately 37 minutes to minutes. The additional 1-2 sprays of complete while the Rad-Release II the Rad-Release solutions was procedure took approximately 65 performed to simulate foam collapse, i.e. minutes.
the reintroduction of fresh Rad-Release 8
The temperature and relative humidity end and the RH was 20% in both (RH) were recorded at the start and instances. According to the vendor, finish. The temperature was 21 °C (70 these conditions were acceptable for use
°F) at the start and 19 °C (66 °F) at the of the Rad-Release solutions.
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4.0 Quality Assurance/Quality Control QA/QC procedures were performed in the duration of the project. Each row accordance with the program QMP and gives the difference between the known the test/QA plan for this evaluation. energy levels and those measured following calibration (rolling average 4.1 Intrinsic Germanium Detector across the six most recent calibrations).
The germanium detector was calibrated Pre-contamination measurements were weekly during the overall project. The performed in late September and the calibration was performed in accordance post-contamination results were with standardized procedures from the measured in late November. Each row American National Standards Institute represents a six week rolling average of (ANSI) and the Institute of Electrical calibration results. In addition, the and Electronics Engineers (IEEE)2. In energies were compared to the previous brief, detector energy was calibrated 30 calibrations to confirm that the results using thorium (Th)-228 daughter gamma were within three standard deviations of rays at 238.6, 583.2, 860.6, 1620.7, and the previous calibration results. All the 2614.5 kilo electron volts (keV). Table calibrations fell within this requirement.
4-1 gives the calibration results across Table 4-1. Calibration Results - Difference from Th-228 Calibration Energies Calibration Energy Levels (keV)
Date Range Energy 1 Energy 2 Energy 3 Energy 4 Energy 5 (2010) 238.632 583.191 860.564 1620.735 2614.533 9-27 to 11-2 -0.003 0.010 -0.039 -0.121 0.017 10-5 to 11-8 -0.003 0.011 -0.029 -0.206 0.023 10-12 to 11-16 -0.004 0.015 -0.040 -0.245 0.031 10-19 to 11-24 -0.005 0.014 -0.001 -0.320 0.043 Gamma ray counting was continued on spectra were sent to a data analyst who each coupon until the activity level of independently confirmed the "activity" Cs-137 on the surface had an RSD of number arrived at by the spectroscopist.
less than 2%. This RSD was achieved When both the spectroscopist and an during the first hour of counting for all expert data analyst independently arrived the coupons measured during this at the same value the data were evaluation. The final activity assigned to considered certified. This process each coupon was a compilation of defines the full gamma counting QA information obtained from all process for certified results.
components of the electronic assemblage that comprises the "gamma counter," The background activity of the concrete including the raw data and the spectral coupons was determined by analyzing analysis described in Section 3.1.3. Final four arbitrarily selected coupons from spectra and all data that comprise the the stock of concrete coupons used for 10
this evaluation. The ambient activity accuracy of the Th-228 daughter level of these coupons was measured for calibration standards (during the time at least two hours. No activity was when the detector was in use) by detected above the minimum detectable measuring the activity of a National level of 2x10-4 µCi on these coupons. Institute of Standards and Technology Because the background activity was not (NIST)-traceable europium (Eu)-152 detectable (and the detectable level was standard (in units of Becquerel, BQ) and more than 2,500 times lower than the comparing it to the accepted NIST value.
post-decontamination activity levels), no Results within 7% of the NIST value are background subtraction was required. considered (according to RML internal quality control procedures) to be within Throughout the evaluation, a second acceptable limits. The Eu-152 activity measurement was taken on five coupons comparison is a routine QC activity in order to provide duplicate performed by INL, but for the purposes measurements to evaluate the of this evaluation serves as the repeatability of the instrument. Three of performance evaluation (PE) audit. This the duplicate measurements were audit confirms the accuracy of the performed after contamination prior to calibration of the germanium detector application of the decontamination critical to the results of the evaluation.
technology and two were performed Table 4-2 gives the results of each of the after decontamination. All five of the audits applicable to the duration of the duplicate pairs showed difference in evaluation including the pre-activity levels of 2% or less, within the decontamination measurements acceptable difference of 5%. performed in late September. All results are below the acceptable difference of 4.2 Audits 7%.
4.2.1 Performance Evaluation Audit RML performed regular checks of the Table 4-2. NIST-Traceable Eu-152 Activity Standard Check NIST Activity INL RML Relative Percent Date (BQ) Result (BQ) Difference 9-15-2010 124,600 122,000 2%
10-13-2010 124,600 123,100 1%
11-10-2010 124,600 121,600 2%
4.2.2 Technical Systems Audit test/QA plan and the data acquisition and A TSA was conducted during testing at handling procedures were reviewed. No INL to ensure that the evaluation was significant adverse findings were noted performed in accordance with the in this audit. The records concerning the test/QA plan. As part of the audit, the TSA are stored indefinitely with the actual evaluation procedures were Contractor QA Manager.
compared with those specified in the 11
4.2.3 Data Quality Audit 4.3 QA/QC Reporting At least 10% of the raw data acquired Each assessment and audit was during the evaluation and transcribed documented in accordance with the into spreadsheets for use in the final test/QA plan. Draft assessment reports report was verified by the QA manager. were prepared and sent to the Test The data were traced from the initial raw Coordinator and Program Manager for data collection, through reduction and review and approval. Final assessment statistical analysis, to final reporting, to reports were then sent to the EPA QA ensure the integrity of the reported Manager and contractor staff.
results.
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5.0 Evaluation Results 5.1 Decontamination Efficacy the contaminated coupons (pre The decontamination efficacy of the decontamination) was within the Rad-Release I and Rad-Release II was acceptable range of 1 µCi +/- 0.5 µCi. The measured for each contaminated coupon overall average (plus or minus one in terms of percent removal (%R) and standard deviation) of the contaminated decontamination factor (DF). Both of coupons was 1.11 µCi +/- 0.041 µCi and these parameters provide a means of 1.0 µCi +/- 0.08 µCi for the coupons used representing the extent of for Rad-Release I and Rad-Release II, decontamination accomplished by a respectively. The post-decontamination technology. The %R gives the extent as coupon activities were less than the pre-a percent relative to the activity and the decontamination activities showing an DF is the ratio of the initial activity to overall reduction in activity for both the final activity or the factor by which technologies. For Rad-Release I, the the activity was decreased. These terms %R averaged 71% +/- 13% and the DF are defined by the following equations: averaged 3.9 +/- 1.5. Overall, the %R ranged from 53% to 82% and the DF
%R = (1-Af/Ao) x 100% ranged from 2.1 to 5.5. For Rad-Release II, the %R averaged 85 +/- 2% and the DF DF = Ao/Af averaged 7.0 +/- 1.1. Overall, the %R ranged from 83% to 88% and the DF where, Ao is the radiological activity ranged from 5.7 to 8.5. A t-test was from the surface of the coupon before performed on the two data sets in order application of Rad-Release I and Rad-to determine the likelihood of generating Release II and Af is radiological activity the observed %R data if the data sets from the surface of the coupon after were not different. The probability of treatment. While the DFs are reported, generating these data sets if the data sets the narrative describing the results were not significantly different was focuses on the %R.
0.133 so at a 95% confidence interval, the Rad-Release I and Rad-Release II Tables 5-1 and 5-2 give the %R and DF were not considered significantly for Rad-Release I and Rad-Release II, different from one another.
respectively. All coupons were oriented vertically. The target activity for each of 13
Table 5-1. Decontamination Efficacy Results for Rad-Release I Coupon Location in Pre-Decon Activity Post-Decon Activity Test Stand (Ci / Coupon) (Ci / Coupon) %R DF Top right 1.08 0.51 53% 2.1 Center middle 1.17 0.36 70% 3.3 Center right 1.09 0.20 82% 5.5 Bottom right 1.10 0.23 79% 4.8 Average 1.11 0.32 71% 3.9 Std. Dev 0.041 0.14 13% 1.5 Table 5-2. Decontamination Efficacy Results for Rad-Release II Coupon Location in Pre-Decon Activity Post-Decon Activity Test Stand (Ci / Coupon) (Ci / Coupon) %R DF Top left 0.97 0.14 85% 6.9 Top middle 1.04 0.12 88% 8.5 Center left 1.12 0.20 83% 5.7 Bottom left 0.96 0.14 85% 6.8 Average 1.0 0.15 85% 7.0 Std. Dev 0.08 0.03 2% 1.1 As described in Section 3.1, the CC contaminated coupons. Therefore, this blank was included in the test stand to result suggested that cross-evaluate the potential for CC due to contamination resulting from the application of Rad-Release I and Rad- application of Rad-Release I and Rad-Release II on wall locations above the Release II on coupons located above the placement of the uncontaminated CC blank was detectable, but minimal.
coupon. In the case of this evaluation, Assuming that the Rad-Release I Rad-Release I was applied to the attained a 71%R on the CC blank, this contaminated coupon in the center residual activity of 0.0218 µCi would middle position. Upon application of the correspond to a pre-decontamination Rad-Release I to the contaminated center activity of 0.1 µCi, consistent with middle coupon, some Rad-Release I ran approximately 10% of the activity from down the wall onto the uncontaminated the coupon located above. The liquid coupon in the bottom middle position. nature of the decontamination solutions Rad-Release I was then applied to the facilitates flow of contamination down CC blank using the same method as for the side of the test stand. However, it is the other coupons. After likely that Rad-Release I and Rad-decontamination, the activity of the CC Release II would not flow as easily blank was found to be 0.0218 µCi. This down the side of an actual concrete wall value was 10 times greater than the as was the case for the stainless steel test minimum detectable level, but more than stand, which would tend to reduce cross-5 times less than the post- contamination.
decontamination activities of the 14
5.2 Deployment and Operational Factors Rad-Release I and Rad-Release II A number of operational factors were behaved very similarly during documented by the technician that application and removal. Both the Rad-performed the testing with the Rad- Release I and Rad-Release II, Solution 1 Release I and Rad-Release II. One of the reacted with the surface of the concrete factors was the degree of difficulty in to create a thin foam of bubbles upon application. The application of Rad- application. EAI indicated that this was Release I and Rad-Release II was likely a release of carbon dioxide due to described in Section 3.2 and included acid-base chemistry occurring at the use of a plastic spray bottle. Application surface of the concrete. Neither Rad-of the Rad-Release I and Rad-Release II Release I nor Rad-Release II caused any solutions to each coupon took 10-15 immediate visible damage to the surface seconds in addition to the recommended of the coupons, however long term dwell time of 30 minutes for each surface changes were not evaluated. The solution. For Rad-Release I, there was Rad-Release II coupons did not dry as only one solution so there was only one quickly as the Rad-Release I coupons.
30 minute dwell time prior to rinsing by Following use of Rad-Release I, the spraying with the deionized water/10% coupons could be removed from the test nitric acid solution and wet vacuum stand almost immediately and be dry to removal (approximately 1 minute per touch, while the Rad-Release II coupons coupon). The total time elapsed for the were left in the test stand overnight five coupons decontaminated with Rad- before removing them from the test Release I was approximately 37 minutes. stand and were still somewhat damp.
For Rad-Release II, there were two Figure 5-1 shows a photograph of the solutions that were applied using the rinse and vacuuming step of the Rad-identical procedure that included a 30 Release procedure. The personal minute dwell time for each. The total protective equipment (PPE) used by the elapsed time for the four coupons technician in the picture was required decontaminated with Rad-Release II was because the work was performed in a approximately 65 minutes. These radiological contamination area using application and removal times are Cs-137 on the concrete coupon surfaces.
applicable only to the experimental Whenever radioactive contaminated scenario including these rather small material is handled, anti-contamination concrete coupons. According to EAI, if PPE will be required and any waste will Rad-Release I and Rad-Release II were be considered low level radioactive applied to larger surfaces, larger waste (and will need to be disposed of application tools such as larger sprayers accordingly). The required PPE was not or foamers would likely be used which driven by the use of the Rad-Release would impact the application rate. In solutions (which are not hazardous),
addition, larger vacuum heads would be rather the interaction with surfaces used for removal. contaminated with Cs-137.
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Figure 5-1. Rinsing and vacuuming Rad-Release from concrete coupon.
Table 5-3 summarizes qualitative and quantitative practical information gained by the operator during the evaluation of Rad-Release I and Rad-Release II. All of the operational information was gathered during use of Rad-Release I and Rad-Release II on the concrete coupons inserted into the test stand. Some of the information given in Table 5-3 could differ if the Rad-Release I and Rad-Release II were applied to a larger surface or to a surface that was smoother or more rough and jagged than the concrete coupons used during this evaluation.
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Table 5-3. Operational Factors Gathered from the Evaluation Parameter Description/Information Decontamination Technology Preparation: Rad-Release I and Rad-Release II are provided ready to use.
rate The solutions were transferred into spray bottles and applied.
Application: The limiting factor of decontamination rate is the surface area covered before the 30 minute dwell times. Larger surfaces would likely utilize sprayer or foamer application. During this experimental design, the initial application to the concrete coupons took only seconds and then the coupons were kept damp (to simulate the ongoing presence of a foam during a large-scale application) with reapplication during the dwell time. Rinsing and vacuuming took approximately one minute per coupon. In all, the application and removal took seven minutes in addition to the 30 minute dwell time for Rad-Release I (for a total elapsed time of 37 minutes) and five minutes in addition to the 60 minute wait time for Rad-Release II.
Aside from the wait times, this corresponds to a decontamination rate of approximately 1 m2/hr for both Rad-Release I and II.
Estimated volumes used included 330 mL of Rad-Release I and Rad-Release II Solution 1, 380 mL Rad-Release II Solution 2, and 440 mL of the rinse solution.
Applicability to Application to irregular surfaces would not seem to be problematic as Rad-Release I irregular surfaces and Rad-Release II are sprayed into hard to reach locations. Removal may be difficult if vacuuming jagged edges or gaps is required.
Skilled labor Adequate training would likely include a few minutes of orientation so the technician requirement is familiar with the application technique including dwell times and requirement of keeping surface wet. Larger surfaces may require more complex equipment such as spray or foam application.
Utilities Electricity for the wet vacuum.
requirement Extent of portability At a scale similar to that used for this evaluation, vacuum removal would be the only portability factor. However, for larger scale applications, limiting factors would include the ability to apply the Rad-Release I and Rad-Release II at an adequate scale and then rinse and remove with a vacuum. Portable electrical generation or vacuum capability may be required.
Secondary waste 1.5 L of liquid was applied to the concrete coupons used during this evaluation. That management volume corresponds to a waste generation rate of approximately 7 L/m2 depending on how much of the solutions absorb to the surfaces. Because Cs-137 was used for this testing, all waste (in vacuum) was solidified and disposed of as low level radioactive waste.
Surface damage Concrete surfaces appeared undamaged.
Cost (material) Rad-Release solutions are not sold as a stand-alone product. EAI, Inc. offers decontamination services which employ the Rad-Release products for which the cost varies greatly from project to project. Typical project costs have been approximately
$33-$55/m2.
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6.0 Performance Summary This section presents the findings from solution using another spray bottle and the evaluation of the Rad-Release I and then removed with a wet vacuum Rad-Release II for each performance (vacuuming took about one minute per parameter evaluated. coupon). Rad-Release II was used in the same way but there were two 6.1 Decontamination Efficacy formulations that went through the The decontamination efficacy (in terms process described above. Therefore, the of %R) attained for Rad-Release I and Rad-Release I application took Rad-Release II was evaluated for each approximately 37 minutes and the Rad-concrete coupon used during the Release II application took evaluation. When the decontamination approximately 65 minutes because the efficacy metrics (%R and DF) of the dwell times were the major factor in the four contaminated coupons application time.
decontaminated with each Rad-Release were averaged together, the average %R The waste generated through use of Rad-for Rad-Release I was 71% +/- 13% and Release I and Rad-Release II was the average DF was 3.9 +/- 1.5. The estimated to be approximately 7 L/m2.
average %R for Rad-Release II was 85% When Rad-Release I and Rad-Release II
+/- 2% and the average DF was 7.0 +/- 1.1. are used on surfaces that are radioactively contaminated, the waste 6.2 Deployment and Operational generated will need to be disposed as Factors radioactive waste. As used for this The application of Rad-Release I and evaluation, only the wet vacuum Rad-Release II was performed using a required electricity. Scaled up plastic spray bottles. For Rad-Release I, applications in remote locations may the concrete coupons were thoroughly require additional utilities to provide wetted with Rad-Release I with 3-4 means for sprayer or foamer application sprays. Then, the solution was worked and vacuum removal. Minimal training into the surface of the coupon by would be required for technicians using scrubbing the entire surface of the Rad-Release I and Rad-Release II, and coupon once with a scouring pad. the surface of the concrete was not During this evaluation, the initial visibly damaged during use. Rad-application of Rad-Release I took only Release solutions are not sold as a stand 10-15 seconds for each coupon. The alone product but along with the next step was a 30 minute dwell time for decontamination service for which the the Rad-Release I to reside on the cost varies greatly from project to surfaces of the concrete coupons. After project. Typical projects cost 30 minutes, the surface of the concrete approximately corresponds to $33 coupons were thoroughly wetted with a $55/m2.
deionized water/10% nitric acid rinse 18
7.0 References
- 1. ASTM Standard C 150-07, 2. Calibration and Use of Germanium Standard Specification for Portland Spectrometers for the Measurement Cement. ASTM International, West of Gamma Emission Rates of Conshohocken, PA, www.astm.org, Radionuclides. American National 2007. Standards Institute. ANSI N42.14 1999. IEEE New York, NY (Rev.
2004).
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