ML12090A687
| ML12090A687 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 07/14/2008 |
| From: | Edington G, Holt-Larese K, O'Neill M, Mallecia Sutton Cellular Bioengineering, Lawrence Livermore National Lab (LLNL), Sandia |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| Shared Package | |
| ML12090A683 | List: |
| References | |
| RAS 22152, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 | |
| Download: ML12090A687 (12) | |
Text
Decontamination of Cs-137, Pu-239, and Am-241 from Hard Surfaces using a Peelable Polymer-based Hydrogel 2008 HPS Annual Meeting Pittsburgh, PA 07/14/08 G. J. Edgington1, M. P. ONeill1, and K.C. Holt-Larese2 Additional work by M. Sutton3, R. P. Fischer3, and M. M. Thoet3 1 Cellular Bioengineering, Inc. (CBI), Honolulu, HI 2 Sandia National Laboratories, Albuquerque, NM 3 Lawrence Livermore National Laboratory (LLNL), Livermore, CA MPM-D.7 NRC000052 Submitted: March 30, 2012
Decon Gel 1101 - What is It?
- Near neutral-pH, low-odor polymer hydrogel
- Utilizes surfactants to lift contaminants
- Soluble chelators bind contaminants for transport
- Contaminants pulled into polymer upon drying
- Entrapped in rehydratable polymer matrix Apply Dry Peel
December 2007 -
- Sandia applied 2nd coat of DG1101 to same test coupons that had been deconned in October.
- Results show 2nd decon efficacies as good or better than 1st application.
Notes: MDA = Minimum detectable activity C Pu = concrete, plutonium; CS Am = carbon steel, americium; SS = stainless steel; P = Plexiglas; etc October 2007 -
CBI commissioned efficacy testing for DG1101 on:
- Concrete (C)
- Stainless steel (SS)
- Plexiglas (P)
Contaminated with:
- Cs-137 0.320 0.403 0.859 P Pu-1 0.310 0.405 0.903 P Pu-2 0.082 0.181 1.045 SS Pu-1 0.021 0.056 0.978 SS Pu-2 0.001 0.009 0.983 CS Pu-1 0.002 0.021 0.977 CS Pu-2 0.078 0.176 1.005 C Pu-1 0.146 0.257 0.902 C Pu-2 0.953 0.912 0.986 0.998 1.002 0.998 0.974 1.006 0.913 1.002 0.947 0.961 0.949 0.994 0.888 0.980 Initial Activity (Ci)
<MDA 0.004 P Cs-2
<MDA 0.005 P Cs-1 0.003 0.019 SS Cs-2 0.008 0.039 SS Cs-1 0.002 0.014 CS Cs-2 0.002 0.010 CS Cs-1 0.745 0.822 C Cs-2 0.737 0.834 C Cs-1 0.001 0.012 P Am-2 0.001 0.011 P Am-1 0.135 0.171 SS Am-2 0.172 0.210 SS Am-1 0.003 0.031 CS Am-2 0.001 0.012 CS Am-1 0.050 0.149 C Am-2 0.063 0.169 C Am-1 Activity after 2nd Decon (Ci)
Activity after 1st Decon (Ci)
Coupon Name
Decontamination Testing of DG 1101 Radionuclide Solutions
- NIST traceable
- Prepared 1uCi/ml from stock solutions
- Am-241: AmCl3 in 1N HCl
- Pu-239: Pu(NO3)4 in 4M HNO3
- Cs-137: CsCl in 0.1M HCl Coupon Materials
- Construction grade concrete cores, uniformly sectioned
- Carbon steel 3 x 3 x 1/8
- 300-series Stainless steel 3 x 3 x 1/4
- PlexiGlas 3 x 3
Decontamination Testing of DG 1101 Coupon Contamination
- Placed on wire racks
- ~1 Ci each deposited using pipettor
- Carbon steel showed visible corrosion Coupon Coating Application and Removal
- Initial counts measured
- Coupons coated with DG1101, spread with spatula and excess allowed to drip off
- 24 hr. dry time
- All coupons easy to peel, most difficult was concrete
- Coatings all removed in single sheet with no fracture
- Carbon steel no longer had visible corrosion on surface
Decontamination Testing of DG 1101 Analytical Method and Data Workup
- Cs-137 counted for 1000 s w/Canberra Ge detector, peak area used to calculate activity
- Am-241 and Pu-239 counted for 120 s w/Ludlum 43-1 and Eberline E600
- Calibration coupons used for all cases
- % Decon = Initial Activity - Final Activity x 100 Initial Activity
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Concrete Carbon steel Stainless steel PlexiGlas Material
% Decon Pu Am Cs 1st decon 2nd decon Results
Pu Glovebox Decon at LLNL Glovebox (~ 4 1/2 ft x 8 ft x 9 ft)
- Cast steel floor, Al walls, Lexan windows and Hypalon gloves
- Commissioned in 1964 to cold roll Pu metal
- In 1996 a spill of Pu-238 occurred
- Measurements at < 1 inch >>1,000,000 cpm (off-scale)
- Previous unsuccessful decontamination efforts involved a commercially available strippable film coating
Field Test DG 1101 Application
- Applied with trowel, allowed to dry overnight
- Lexan window deconned 2x, Steel floor and Al siding 3x
- DFs measured as ratio of original alpha activity at 1.5 inch stand-off to activity measured after each decon
- Initial contamination levels averaged
- 74,000 dpm for cast steel horizontal floor
- 56,000 dpm for aluminum siding
- 54,000 dpm for Lexan window
Results One application
- Activity on steel floor was reduced by 57% (SD=7%) and on the Lexan window by 37% (SD=8%)
Additional applications
- Lexan window after 2nd application overall 99.5% removal (SD=0.1%)
- Steel floor after 2nd and 3rd application overall 99.4% (SD=0.3%)
- After 2 and 3 applications of DG 1101, activity was reduced to <400 dpm in almost all cases
- Given the highly contaminated nature of the surfaces within the glove-box, this decontamination efficiency is considered excellent
Operational Perspectives The Nuclear Materials Processing and Technology Program personnel conducting the decon activities reported that the material had a good workability and allowed sufficient working time before drying.
In general the material adhered to the sides of the glove-box without an excessive amount of dripping being observed.
DG 1101 was able to penetrate crevices and was easily removed from all surfaces with the exception of the Hypalon gloves.
While hand application was used for the study, personnel commented that spray application might be advantageous for future applications.
[Comment from CBI: DG 1120 is now available for spray applications.]
Summary
- Lab Environ
- Decon Gel 1101 demonstrated effective on Pu-239, Am-241, and Cs-137 radioisotopes
- 2nd decon factors as good or better than 1st application
- Cs on concrete most difficult case, R&D in progress
- Field Application
- Application of DG 1101 to Pu decon of highly contaminated glovebox at LLNL demonstrated excellent efficacy overall
- Full Reports Available
- Sandia and LLNL reports available upon request at CBI booth or contact M. ONeill, CTO, CBI
- moneill@cellularbioengineering.com