Text

Survey Units 6 and 7 Surface Soil Characterization
	ML18177A202
Person / Time
Site:	Erwin
Issue date:	05/31/2018
From:	; Wood Environment & Infrastructure Solutions
To:	; Office of Nuclear Material Safety and Safeguards
Shared Package
ML18177A173	List: ML18177A201; ML18177A202;
References
	21G-18-0061, ACF-18-0122, GOV-01-55-06
	Download: ML18177A202 (54)
	v • d • e

21 G-18-0061 GOV-01-55-06 ACF-18-0122 ADDENDUM TO THE FINAL STATUS SURVEY REPORT FOR SURVEY UNITS 4,6, 7, 12, 16, 17, 18 NUCLEAR FUEL SERVICES NORTH SITE Erwin, Tennessee SURVEY UNITS 6 AND 7 SURFACE SOIL CHARACTERIZATION PREPARED FOR:

BWXT NUCLEAR FUEL SERVICES, INC.

PREPARED BY:

WOOD ENVIRONMENT & INFRASTRUCTURE SOLUTIONS, INC.

WOOD PROJECT No. 910217003 REVISION 0 MAY 2018 W ORK PERFORMED UNDER PURCHASE O RDER NO. SC04004-l wood.

ADDENDUM TO THE FINAL STATUS SURVEY REPORT FOR SURVEY UNITS 4,6, 7, 12, 16, 17, 18 NFS North Site-SURVEY UNITS 6 AND 7 SURFACE SOIL CHARACTERIZATION NUCLEAR FUEL SERVICES NORTH SITE Erwin, Tennessee US NRC SNM License Number 124 Docket Number 70-143 Prepared for:

BWXT Nuclear Fuel Services, Inc.

1205 Banner Hill Road Erwin, TN 37650 Prepared by:

wood.

2275 Logos Court, Suite A Grand Junction, CO 81505 Contract No. SC4004-1 Project No. 910217003 Revision 0 May 2018 wood.

SU6 and SU7 Surface Soil Characterization Revision 0 Page i FSS Report Addendum May 2018

Table of Contents 1

INTRODUCTION............................................................................................................................................... 1 1.1 Project Objective................................................................................................................................... 1 2

RESULTS.............................................................................................................................................................. 3 2.1 Survey Unit 6........................................................................................................................................... 3 2.1.1 In-Situ Static Gamma Spectroscopy Measurement............................................................ 3 2.1.2 Surface Soil Samples....................................................................................................................... 8 2.1.3 Gamma Scanning Results........................................................................................................... 13 2.2 Survey Unit 7......................................................................................................................................... 15 2.2.1 In-Situ Static Gamma Spectroscopy Measurement......................................................... 15 2.2.2 Surface Soil Samples.................................................................................................................... 21 2.2.3 Gamma Scanning Results........................................................................................................... 25 2.3 Phase 2 Investigation........................................................................................................................ 28 2.3.1 Systematic Sampling Design..................................................................................................... 29 2.3.2 Area A................................................................................................................................................ 29 2.3.3 Area B................................................................................................................................................ 34 3

QUALITY CONTROL..................................................................................................................................... 40 3.1 ScanPlot5M.............................*.....*.........*...**..*...***.*.*..*.***.*. **.*.*.*.*..*.**.**..*.....*.*..*. *.**.***.*.**.**..******** ** *.**. 40 3.2 Laboratory Analysis........................................................................................................................... 42 4

CONCLUSION.................................... :........................................................................................................... 43 5

ACRONYMS.................................................................................................................................................... 44 6

REFERENCES................................................................................................................................................... 45 APPENDIX A........................................................................................................................................................... A-1 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page ii FSS Report Addendum May 2018

Figure 1.

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Table 1.

Table 2.

Table 3.

Table 4.

Table 5.

Table 6.

Table 7.

Table 8.

Table 9.

Table 10.

Table 11.

Table 12.

Table 13.

Table 14.

Table 15.

Table of Figures SU6 Sample Locations

............................................................................................... 3 SU6 In-Situ Descriptive Statistics K-40................................................................................... 4 SU6 In-Situ Descriptive Statistics Am-241................................................................................. 5 SU6 In-Situ Descriptive Statistics U-235.................................................................................... 5 SU6 In-Situ Descriptive Statistics Th-232............................................................................... 6 SU6 Soil Sample Statistics Summary Am-241.......................................................................... 9 SU6 Soil Sample Statistics Summary U-235............................................................................ 10 SU6 Soil Sample Statistics Summary Th-232

............................................................... 10 SU6 Gross Gamma Map (cps)............................................................................................... 13 SU6 Am-241 Gamma Map (cps)........................

...................................... 14 SU6 U-235 Gamma Map (cps)..........................

......................................... 14 SU6 Th-232 Gamma Map (cps)

................................................ 15 SU7 Sample Locations.................................................

............................................. 16 SU7 In-Situ Descriptive Statistics K-40........................

...................................................... 17 SU7 In-Situ Descriptive Statistics Am-241............................................................................. 18 SU7 In-Situ Descriptive Statistics U-235.

.................................................... 18 SU7 In-Situ Descriptive Statistics Th-232.............................................................................. 19 SU7 Soil Sample Statistics Summary Am-241............

................................................... 21 SU7 Soil Sample Statistics Summary U-235.......................................................................... 22 SU7 Soil Sample Statistics Summary Th-232.......................................................................... 22 SU7 Gross Gamma Map (cps)............................................................................................... 26 SU7 Gross Am-241 Gamma Map (cps).......................................................................

.... 26 SU7 Gross U-235 Gamma Map (cps)................................................................................... 27 SU7 Net Th-232 Gamma Map (cps)......................................................................................... 27 Areas A & B...........

........................................................................................... 28 Area Sampling Plan............................................................................................................... 29 Area A Interpolation...............................................

.................................................. 31 Area A SOF Comparison...................................................................................................... 33 Area B Interpolation............................................................................................................. 36 Area B SOF Comparison............

............................................................... 38 SU6 K-40 Gamma Map (cps).....

.................................................... 41 SU7 K-40 Gamma Map (cps)...

................................................... 41 Table of Tables North Site Surface Soil DCGLs.........................

.............................................................. 2 SU6 In-Situ Corehole Gamma Spectrometry Measurements..................................................... 7 SU6 Soil Sample Results....................................................................................................... 11 SU7 In-Situ Corehole Gamma Spectrometry Measurements................................................... 20 SU7 Soil Sample Results....................................................................................................... 24 Area A Soil Sample Results................................................................................................... 30 Area A Spatially Weighted Am-241 Values.............................................................................. 32 Area A Spatially Weighted U-235 Values................................................................................. 32 Area A Spatially Weighted Th-232 Values............................................................................... 33 SU7 & Area A SOF Evaluation.....

..................................................... 34 Area B Soil Sample Results..............................................

............................................... 35 Area B Spatially Weighted Am-241 Values.................

.............................................,..... 37 Area B Spatially Weighted U-235 Values................................................................................ 37 Area B Spatially Weighted Th-232 Values............................................................................. 38 SU7 & Area B SOF Evaluation................................................................................................. 39 wood.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 Page iii FSS Report Addendum May 2018

This page intentionally left blank NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page ii FSS Report Addendum May 2018

1 INTRODUCTION This report provides a summary of the surface soil investigations performed in Survey Units (SU) 6 and 7 at BWXT Nuclear Fuel Services, Inc. (NFS) North Site by Wood Environment &

Infrastructure Solutions, Inc., (Wood), formerly Amee Foster Wheeler Environment &

Infrastructure, Inc. (AmecFW), and MACTEC Development Corp. (MACTEC). Survey Units 6 and 7 subsurface soils were previously characterized as part of the Subsurface Soil Characterization and Final Status Survey (FSS) Project. The subsurface soils passed the requirements for free release. However, this surface soil survey and investigation were performed to respond to the request for additional information (RAI) process from Nuclear Regulatory Commission (NRC) staff.

1.1 PROJECT OBJECTIVE The NFS North Site Surface Soil Survey Project objective was to execute a radiological survey and investigation focused on the surface soils (top 15 cm) for SU6 and SU7 to augment the previously completed FSS. The detailed survey design is provided in the NFS North Site Surface Soil Survey Project Field Sampling Plan (FSP}, NFS-PLN-001 Rev. 1, (AmecFW 2017).

The survey was designed to evaluate the radiological condition of the survey units in a manner that would be comparable to the methodology utilized and data generated under the NFS North Site Subsurface Soil Characterization and Final Status Survey Project. The design included the following measurements for each survey unit.

1) In-situ static gamma spectroscopy measurements performed at each of the previously established corehole locations,

2) Collection of surface soil samples (250 ml volume sample from each location) from the top 15 cm (6 inches) of the surface at each of the corehole locations,

3) Gamma spectroscopy scanning measurements performed across the accessible areas of the survey units, and

4) Investigation of locally elevated measurements in SU7.

The survey was performed August/September 2017, with the Phase 2 investigation conducted in January/ February 2018. Results of the survey were compared to the established radioactivity surface soil Derived Concentration Guidance Levels (DCGLs) provided in Table 1.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 1 FSS Report Addendum May 2018

Table 1.

North Site Surface Soil DCGLs Isotope DCGL (pCi/g)

Am-241 130 Pu-238 155 Pu-239 140 Pu-240 141 Pu-241 4365 Pu-242 148 Tc-99 414 Th-230 17 Th-232 3.7 U-233/234<al 642 U-235 74 U-238 306 CalDCGL is for the sum of U-233 and U-234 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 2 FSS Report Addendum May 2018

2 RESULTS 2.1 SURVEY UNIT 6 2.1.1 In-Situ Static Gamma Spectroscopy Measurement In-situ static measurements were taken at each corehole location (Figure 1) that was established as part of the subsurface characterization of the North Site. The measurements were performed by positioning the ScanPlot5M push cart platform over each of the 60 corehole locations and collecting a stationary, 5-minute, spectral gamma measurement. Gamma spectra were collected using Wood proprietary data collection software.

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Page 3 FSS Report Addendum May 2018

Subsequently, the spectra were processed in order to calculate the gross counts in a number of regions of interest (ROI) associated with the isotopes of interest (americium-241 [Am-241],

uranium-235 [U-235], thorium-232 [Th-232], radium-226 [Ra-226] and potassium-40 [K-40]). Net photo peak counts were then derived for K-40, Ra-226, and Th-232. The net Th-232 count rates were also converted to soil concentrations in pCi/g for direct comparison with the surface soil DCGL. Ra-226 and K-40 were reported to be able to isolate the gamma signals from the isotopes of interest from the naturally present isotopes.

ProUCL Version 5.1 (EPA 2016) is a statistical software package developed and updated by the EPA. It was used to generate summary statistics and histograms from the field and analytical data.

The generated histograms include summary statistics and display a fitted normal distribution curve as a background, providing a visual indication of the normality of the data or lack thereof.

Histograms of the data points compared to a normal distribution, and general summary statistics for K-40 and the primary gamma-emitting isotopes of interest are provided in the sequence of figures from Figure 2 to Figure 5. Results of the in-situ static measurements are presented in Table 2.

Net K-40 (cps)

Net K-40 (cps) 40 Number of Values 60 Minimum 71.00 35 Maximum 271.00 30 SD 36.46 Skewness

-3.05 13' 25 C:

Kurtosis 9.54 Q) 5-20 0Mean 235.47 Q)

Li:

15 0Median 246.00

~ Normal Distribution 10 5

1 0 -

1 2

1 1

---~~-----

D Less Bins D More Bins 80 120 160 200 240 280 cps Figure 2.

SU6 In-Situ Descriptive Statistics K-40 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 4 FSS Report Addendum May 2018

SU 6 Gross Am-241 GrossAm-241 [cps]

35 Number of Values 63 Minimum 123.95 30 MaKimum 184.87 SD 11.39 25 Skewness

-3.10 g 20 II)

Kurtosis 11.02 0Mean 174.14 r::r J: 15 OMedian 176.68

~ Normal Distribution 10 0 Less Bins 5

0 More Bins 2

0 -

0 0

2 2

2 1

-=---.,,.---- -

134 146 158 171 183 cps Figure 3.

SU6 In-Situ Descriptive Statistics Am-241 SU 6 Gross U-235 Gross U-235 [cps]

Number of Values 28 Minimum MaKimum 204.

24 SD 16.44 20 Skev-.oness

-3.21 G

C Kurtosis 11.08

!l 16 r::r 0Mean 190.54 II)

~ 12 0Median 195.20

~ Normal Distribution 8

4 2

0 -

0 0 Less Bins 0 More Bins 120 137 155 172 189 cps Figure 4.

SU6 In-Situ Descriptive Statistics U-235 NFS North Site-SU6 and SU? Surface Soil Characterization Revision 0 wood.

Page 5 FSS Report Addendum May 2018

SU6 Net Th-232 Net T~ 232b (pCi/g]

30 Number of Values 63 Minimum 0.90 27 Maximum 1.53 24 SD 0.12 Skewness

-2.84 21 Kurtosis 9.57 G 18 O Mean 1.41 C:

0 Median 1.46

., g 15

~ Normal Distribution u::

12 9

OLess Bins OMore Bins 6

3 2

0 -

0 1.00 1.13 1.25 1.38 1.50 pCi/g Figure 5.

SU6 In-Situ Descriptive Statistics Th -232 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 6 FSS Report Addendum May 2018

Table 2.

SU6 In-Situ Corehole Gamma Spectrometry Measurements Corehole Net Gross Location K-40 Am-241

[cps]

750 137 153 751 152 151 752 249 177 753 252 177 754 255 180 755 228 175 756 247 175 757 249 181 758 251 179 759 248 177 760 252 177 761 258 176 762 253 179 763 246 182 764 247 177 765 244 176 766 242 176 767 246 177 768 242 174 769 249 178 770 241 178 771 239 173 772 246 175 773 242 175 774 247 176 775 244 175 776 271 184 777 247 174 778 242 173.

779 241 174 780 250 177 781 243 180 782 264 180 783 261 185 784 250 175 785 245 175 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 Gross U-235

[cps]

164 165 196 198 201 192 195 198 200 197 199 197 197 196 196 194 193 199 195 198 195 189 195 191 196 193 204 195 191 192 196 197 199 204 192 192 wood.

Page 7 Net Ra-226

[cps]

10 10 11 12 12 10 10 10 10 11 11 12 11 10 11 11 10 11 11 11 10 10 11 11 11 11 9

10 11 11 10 10 10 9

9 11 Net Net Th-232 Th-232

[cps]

[pCi/g]

20 1.39 20 1.39 21 1.46 21 1.46 22 1.53 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 22 1.53 22 1.53 22 1.53 20 1.39 21 1.46 21 1.46 21 1.46 22 1.53 21 1.46 22 1.53 20 1.39 20 1.39 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 21 1.46 20 1.39 21 1.46 21 1.46 FSS Report Addendum May 2018

Table 2.

SU6 In-Situ Corehole Gamma Spectrometry Measurements Corehole Net Gross Gross Net Net Net Location K-40 Am-241 U-235 Ra-226 Th-232 Th-232

[cps]

[pCi/g]

786 249 176 194 10 21 1.46 787 240 184 200 11 21 1.46 788 237 185 198 12 20 1.39 789 243 179 195 10 19 1.32 790 255 177 195 10 20 1.39 791 252 182 199 11 19 1.32 792 254 174 192 11 21 1.46 793 252 176 195 10 21 1.46 794 71 124 118 10 13 0.90 795 104 156 149 10 15 1.04 796 233 183 197 12 21 1.46 797 245 179 196 10 19 1.32 798 257 181 201 11 20 1.39 799 248 181 197 10 19 1.32 800 199 165 176 11 20 1.39 801 184 159 169 11 19 1.32 802 239 176 193 10 20 1.39 803 251 180 197 10 20 1.39 804 248 181 201 10 19 1.32 805 249 177 196 10 20 1.39 806 243 179 195 9

20 1.39 807 232 171 186 9

20 1.39 808 244 173 190 10 20 1.39 809 179 165 171 9

18 1.25 2.1.2 Surface Soil Samples Soil samples were collected from the top 6 inches of surface soil at each of the 60 corehole locations in SU6. Samples were collected, packaged, labeled, and transferred to the NFS Non-Destructive-Assay (NOA) laboratory in accordance with the FSP.

Each sample was analyzed by the NFS NOA laboratory in September/October 2017 for U-235, Th-232, Am-241, and U-238 via gamma spectroscopy. Activity results were moisture-corrected.

Descriptive statistics and a data histogram for each isotope are provided in the sequence of figures from Figure 6 to Figure 8. The generated histograms display a background, fitted normal distribution curve providing a visual indication of the normality of the data or lack thereof. The individual sample results are all below the applicable site surface DCGLs provided in Table 1. The NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 8 FSS Report Addendum May 2018

individual analytical results for all SU6 soil samples and field duplicate measurements are presented in Table 3.

Table 3 includes Sum of Fractions (SOF) calculations for each sample location and the SU6 mean, using the isotope of interest versus the respective surface soil DCGL. To be conservative, isotopes of interest with reported activities less than O were assigned a value of O for the calculation. All SOF scores are below unity (1.0).

30 27 24 21 G 18 C:.,

fr 15 Li:

12 9

6 3

0

-0.26 SU6 Am-241 Soil Samples 0.00 0.26 pCi/g 0.52 Am-241 Number of Values Minimum Maximum SD Skewness Kurtosis 0Mean 0Median

~ Normal Distribution D Less Bins OMore Bins 0.78 Figure 6.

SU6 Soil Sample Statistics Summary Am-241 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 9 FSS Report Addendum May 2018 6

-0.37 0.93 0.26 1.28 2.07 0.15 0.04

16 14 12 10 6

4 2

0.03 0.05 SU6 U-235 Soil Results 0.08 0.11 0.14 pCi/g 0.16 0.19 U-235 Number of Values Minimum Mawimum SD Skewness Kurtosis OMean 0 Median

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N 01mal Distribution 0 Less Bins 0 More Bins 0.22 0.24 0.27 Figure 7.

SU6 Soil Sample Statistics Summary U-235 SU6 Th-232 Soil Samples 14 12 10 G

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0.39 0.78 1.1 7 1.56 1.95 pCi/g 2.34 Th-232 Number of Values Minimum Maximum SD Skewness Kurtosis 0Mean D Median

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SU6 Soil Sample Statistics Summary Th-232 NFS North Site-SU6 and SU? Surface Soil Characterization Revision 0 wood.

Page 10 FSS Report Addendum May 2018 0.00 0.27 0.06 0.52 0.32 0.12 0.12 0.38 2.33 0.41

-0.42 0.38 149 1.52

Table 3.

Date Net Sample ID Analyzed Weight 0750-SS-FS 9/12/2017 305.2 0751-SS-FS 9/12/2017 297.2 0752-SS-FS 9/12/2017 282.3 0753-SS-FS 9/12/2017 278.6 0754-SS-FS 9/12/2017 272.3 0755-SS-FS 9/12/2017 276.1 0756-SS-FS 9/12/2017 264.4 0756-SS-FD 10/4/2017 266.8 0757-SS-FS 9/13/2017 260.5 0758-SS-FS 9/13/2017 256.1 0759-SS-FS 9/13/2017 280.2 0759-SS-FD 10/5/2017 281 0760-SS-FS 9/13/2017 301.9 0761-SS-FS 9/14/2017 281.6 0762-SS-FS 9/14/2017 284.4 0763-SS-FS 9/14/2017 247.2 0764-SS-FS 9/14/2017 250 0765-SS-FS 9/14/2017 269.5 0766-SS-FS 9/15/2017 263.7 0767-SS-FS 9/15/2017 259.6 0768-SS-FS 9/15/2017 285 0769-SS-FS 9/15/2017 258.3 0770-SS-FS 9/15/2017 263.8 0771-SS-FS 9/15/2017 286.9 0772-SS-FS 9/18/2017 282.7 0773-SS-FS 9/18/2017 252.1 0774-SS-FS 9/18/2017 248.2 0775-SS-FS 9/18/2017 289 0776-SS-FS 9/18/2017 263.5 0777-SS-FS 9/19/2017 268.6 0778-SS-FS 9/19/2017 262.5 0779-SS-FS 9/19/2017 258.1 0780-SS-FS 9/19/2017 282.8 0781-SS-FS 9/19/2017 269.9 0782-SS-FS 9/19/2017 256.6 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 SU6 Soil Sample Results Moisture U-235 1.9 0.08 7.2 0.1 11.9 0.15 11 0.05 9.3 0.19 8.2 0

8.7 0.09 6.9 0.12 10.2 0.13 11.3 0.13 9.2 0.24 10.1 0.22 13.1 0.12 10.8 0.17 10 0.18 8.5 0.13 8.8 0.14 8.3 0.1 13.3 0.17 10.3 0.15 13.6 0.11 12 0.04 10.7 0.07 13.1 0.06 9.9 0.12 10.4 0.27 10.8 0.1 13.1 0.12 9.8 0.27 10.1 0.05 12.3 0.12 11.4 0.1 11.4 0.05 8.3 0.1 11.5 0.09 wood.

Page 11 Moisture-Corrected Result U-238 4.33 0

9.89 1.86 3.55 11.88 11.27 3.94 0

6.14 2.74 10.62 1.22 1.92 5.02 0

1.29 0

3.84 0

0 0

0 4.47 0

0 0

0 5.54 0

0 0

0 0.52 0

Th-232 Am-241 1.52 0.61 1.89 0.29 1.49 0

1.81 0.4 1.4 0.52 1.77 0

1.52 0.56 1.53 0

2.03 0

2.04 0

2.33 0.33 1.34 0.09 1.57 0.17 2.06 0.04 1.69 0.04 1.94 0

1.53

-0.37 1.48 0.05 1.31 0

1.49 0

0.99 0

1.17 0.23 1.25 0

1.42 0.1 1.89 0.26 1.17 0.16 1.37 0.33 1.77 0.01 2.08 0

1.34 0.55 1.6 0

1.59 0

1.66 0.27 1.81 0.27 1.37 0

FSS Report Addendum May 2018 SOF 0.43 0.51 0.44 0.50 0.40 0.52 0.45 0.43 0.55 0.57 0.64 0.40 0.43 0.57 0.48 0.53 0.42 0.40 0.37 0.40 0.27 0.32 0.34 0.40 0.51 0.32 0.37 0.48 0.58 0.37 0.43 0.43 0.45 0.49 0.37

r; bl 3 a e Date Net Sample ID Analyzed Weight 0783-SS-FS 9/19/2017 268.1 0784-SS-FS 9/19/2017 269.6 0785-SS-FS 9/19/2017 274.5 0786-SS-FS 9/20/2017 275.7 0787-SS-FS 9/20/2017 268.2 0788-SS-FS 9/21/2017 255.6 0789-SS-FS 9/21/2017 258.8 0790-SS-FS 9/21/2017 251.5 0791-SS-FS 9/21/2017 278.8 0792-SS-FS 9/21/2017 254.4 0793-SS-FS 9/25/2017 265.4 0794-SS-FS 9/25/2017 252 0795-SS-FS 9/25/2017 260.8 0796-SS-FS 9/25/2017 258.4 0797-SS-FS 9/25/2017 268.4 0798-SS-FS 9/25/2017 265 0799-SS-FS 9/26/2017 271.3 0800-SS-FS 9/26/2017 248.6 0801-SS-FS 9/26/2017 246.8 0802-SS-FS 9/26/2017 240.4 0803-SS-FS 9/26/2017 256.7 0804-SS-FS 9/26/2017 265.3 0805-SS-FS 9/26/2017 232.9 0806-SS-FS 9/26/2017 247.8 0807-SS-FS 9/26/2017 224.3 0808-SS-FS 9/26/2017 256 0809-SS-FS 9/26/2017 246.9 0809-SS-FD 10/5/2017 253.1 SU6 Mean Standard Deviation NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 SU6 S *1 S 01 l R amp.e esu ts Moisture U-235 7.5 0.1 11.7 0.09 11.9 0.17 11 0.09 8.8 0.25 10.8 0.09 11.8 0.21 8.9 0.24 8.9 0.14 11.2 0

9.2 0.21 10.3 0.1 12.4 0.07 10.1 0.08 10.7 0.13 9.4 0.09 7.7 0.11 8.7 0.05 12 0.14 11.6 0.1 9.7 0.15 8.5 0.16 10.9 0.09 12 0.13 15.6 0.15 9.3 0.12 14.3 0.08 14.5 0.15 0.12 0.06 wood.

Page 12 Moisture-Corrected Result U-238 0

0 0

9.5 17.5 0

18.62 2.51 0

0.36 11.11 2.38 0

0 3.66 0

16.08 0

5.04 0

0 0

0 12.15 1.62 18.03 13.62 0.94 3.54 5.22 Th-232 Am-241 0.82 0

1.14 0

1.52 0

1.24 0.06 2.17 0

1.03 0

0.38 0

1.13 0.93 1.11 0

0.67 0

1.07 0.45 1.3 0

1.03 0

1.25 0.05 1.52 0.58 1.24 0

1.89 0.27 1.91 0.36 1.71 0

1.69 0

1.61 0.35 1.94 0

1.66 0

1.94 0.04 1.63 0.87 1.04 0.14 1.7 0.2 0.86 0.10 1.50 0.15 0.38 0.23 FSS Report Addendum May 2018 SOF 0.22 0.31 0.41 0.37 0.65 0.28 0.17 0.32 0.30 0.18 0.33 0.36 0.28 0.34 0.43 0.34 0.57 0.52 0.48 0.46 0.44 0.53 0.45 0.57 0.45 0.34 0.51 0.24 0.42

2.1.3 Gamma Scanning Results Gamma scanning was performed using the SconPlof'M system, with a large volume (-4L),

spectroscopy-grade Nal detector, digital spectrometer, and a survey-grade GPS system configured on a push cart. Spectral data was acquired every second while the push cart moved at a survey speed of approximately 1 meter per second (mps), on 1 m transects. Each data point is representative of an area of approximately 5 m2. The spectral data was processed in a manner similar to the in-situ static measurement data. Net photo peak count rates were determined for a variety of ROis for isotopes of interest.

Two-dimensional, color-scale maps of the gross gamma, gross Am-241, gross U-235, and net Th-232 radiological count rates were generated and are provided in the sequence of figures from Figure 9 to Figure 12. The plotted scan data for SU6 reveals that the surface activity is essentially uniform and that there are no spatially correlated elevated areas of concern.

Figure 9.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 SU6 Gross Gamma Map (cps) wood.

Page 13 FSS Report Addendum May 2018

Figure 10.

Figure 11.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 SU6 Am-241 Gamma fvlap (cps)

SU6 U-235 Gamma fvlap (cps) wood.

Page 14 FSS Report Addendum May 2018

Net Th-232 Oet-1 {No Aggregabon)

Figure 12.

SU6 Th -232 Gamma Map (cps) 2.2 SURVEY UNIT 7 2.2.1 In-Situ Static Gamma Spectroscopy Measurement In-situ static measurements were taken at each corehole location (Figure 13) that were established as part of the subsurface characterization of the North Site. The measurements were performed by positioning the ScanPlot5M push cart platform over each of the 32 corehole locations, and collecting a stationary, 5-minute, spectral gamma measurement. Gamma spectra were collected using Wood proprietary data collection software.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 15 FSS Report Addendum May 2018

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A *I!

_ !!!!!!!!!!!!li* iiii....

i -

0 0

1028 1tm Erwin, TN

~ MACTEC Figure 13.

SUl Sample Locations wood.

SU6 and SU7 Surface Soil Characterization Revision 0 Page 16 1

j l l 1

J l

~

- BRP07/1Q/10 l

~

AUl.07119'10 Stney Unit 7 Prqect 9120.Q7-235 Figure 7 FSS Report Addendum May 2018

Subsequently, the spectra were processed in order to calculate the gross counts in a number of ROI associated with the isotopes of interest. Net photo peak counts were then derived for K-40, Ra-226, and Th-232. The net Th-232 count rates were also converted to soil concentrations in pCi/g for direct comparison with the surface soil DCGL. Ra-226 and K-40 were reported to be able to isolate the gamma signals from the isotopes of interest from the naturally present isotopes..

The generated histograms include summary statistics and display a fitted normal distribution curve as a background, providing a visual indication of the normality of the data or lack thereof.

The in-situ data for all isotopes did not follow a normal distribution. Histograms are provided in the sequence of figures from Figure 14 to Figure 17. Table 4 presents the results of the in-situ static measurements.

9 8

7 6

3 2

0 21 41 SU7 Net K-40 cps 2

2 2

11_11111 62 82 103 124 144 165 185 206 226 cps Net 1(-40 cps Number of Values 32 Minimum 22.08 Maximum 227.93 SD 7128 Skewness 0.03 Kurtosis

-1.64 0Mean 117.05 0Median 119.89

~

Normal Distribution D Less Bins D More Bins Figure 14.

SU7 In-Situ Descriptive Statistics K-40 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 17 FSS Report Addendum May 2018

10 9

8 7

,., 6 0 C (I) 5

s O"

(I)

LL 4

3 2

0 Title 71 SU7 Gross.Am-241 94 11 8 cps 141 GrossAm-241 [cps]

Number of Values 35 Minimum 64.07 Maximum 181.81 SD 40.74 Skewness

0.11 Kurtosis

1.57 0Mean 121.35 D Median 134.01

~ Normal Distribution D Less Bins D More Bins 165 Figure 15.

SU7 In-Situ Descriptive Statistics Am-241 9

8 7

6 3

2 0

57 SU 7 Gross U-235 2

2 2

2 011111 85 113 141 170 198 cps Gross U-235 (cps)

Number of Values 35 Minimum 52.58 Maximum 194.06 SD 49.02 Skewness

0.16 Kurtosis

1.58 0Mean 123.37 0Median 131.60

~

Normal Distribution 0 Less Bins 0More Bins Figure 16.

SU7 In-Situ Descriptive Statistics U-235 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 18 FSS Report Addendum May 2018

r'.

SU7 Net Th-232 Net Th-232b [pCi/g) 9 Number of Values 8

Minimum Ma~imum 7

SD 6

Skewness g 5 Kurtosis 0Mean 0-~ 4 LL 0Median 3

3 I.I 2

0

~

Normal Distribution D Less Bins DMore Bins 0.26 0.51 0.77 1.02 1.28 1.53 pCi/g Figure 17.

SU7 In-Situ Descriptive Statistics Th -232 NFS North Site-SU6 and SU? Surface Soil Characterization Revision 0 wood.

Page 19 FSS Report Addendum May 2018 35 0.29 1.57 0.42

-0.34

-1.45 0.98 1.08

Table 4 SUl In-Situ Corehole G Corehole Net Gross K-40 Am-241 Location

[cps]

7001 146 157 7002 225 182 7003 127 146 7004 141 156 7005 228 182 7006 161 151 7007 203 168 7008 174 167 7009 185 156 7010 97 122 7011 26 71 7012 84 135 7013 48 92 7014 36 79 7015 113 105 7016 27 66 7017 22 68 7018 62 84 7019 27 75 7020 25 71 7021 22 64 7022 52 92 7023 205 160 7024 170 134 7025 74 99 7026 191 154 7027 206 152 7028 57 73 7029 173 143 7030 206 152 7031 195 149 7032 36 73 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 Gross U-235

[cps]

162 191 145 159 194 159 178 173 166 122 61 132 88 70 108 61 56 79 65 60 53 94 173 144 97 167 168 71 153 170 165 66 wood.

Page 20

s.

Net Ra-226

[cps]

10 11 9

10 11 10 10 11 10 9

7 10 8

7 8

7 6

6 6

8 9

9 7

9 10 7

9 10 9

7 M

Net Net Th-232 Th-232

[cps]

[pCi/q]

23 1.57 20 1.39 18 1.23 18 1.26 20 1.36 18 1.29 20 1.38 19 1.29 18 1.27 13 0.94 5

0.38 15 1.08 13 0.92 7

0.46 12 0.82 7

0.47 4

0.29 9

0.60 7

0.51 7

0.45 4

0.31 14 1.00 20 1.40 17 1.18 9

0.65 20 1.41 20 1.41 7

0.52 18 1.26 20 1.40 19 1.32 7

0.50 FSS Report Addendum May 2018

2.2.2 Surface Soil Samples Soil samples were collected from the top 6 inches of surface soil at each of the 32 corehole locations in SU7. An additional sample was collected from an area of elevated gamma scan measurements within SU7 and labeled 7-HS-SS-FS. Samples were collected, packaged, labeled, and transferred to the NFS NDA laboratory in accordance with the FSP.

Samples were analyzed by the NFS NDA laboratory in September/October 2017 for U-235, U-238, Th-232, and Am-241 via gamma spectroscopy. Results were moisture-corrected to calculate activity. The sample results for each isotope are summarized with histograms and descriptive statistics provided in the sequence of figures from Figure 18 to Figure 20. The generated histograms display a background, fitted normal distribution curve providing a visual indication of the normality of the data or lack thereof. The individual corehole sample results are all below the applicable site surface DCGLs provided in Table 1.

24 22 20 18 16 g 14

~ 12 10 B

6 4

2 0

0.00 SU7 Am-241 2

2 II _Q_ 11111 II~ --=-------

0.08 0.17 0.25 0.34 0.42 pCi/g A111-241 Number of Values Minimum Maximum SD Skewness Kurtosis OMean 0Median

~

Normal Distribution D Less Bins OMoreBins Figure 18.

SU7 Soil Sample Statistics Summary Am-241 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 21 FSS Report Addendum May 2018 34 0.00 0.42 0.09 2.61 7.38 0.05 0.00

SU7 U-235 U-235 14 Number of Values 34 Minimum 0.00 12 Maximum 0.47 SD 0.09 10 Skewness 1.67 Kurtosis 5.39 0Mean 0.1 2 D Median 0.11 G 8 C

OJ

~

Normal Distribution O"

OJ Li: 6 4

D Less Bins OMoreBins 2

0 0.00 pCi/g Figure 19.

SU7 Soil Sample Statistics Summary U-235 8

7 6

5 G

C

~4 cr OJ Li:

3 2

0 0.00 0.46 SU7 Th-232 0.92 1.37 1.83 2.29 pCi/g Th-232 Number of Values 34 Minimum 0.00 Maximum 2.29 SD 0.71 Skewness

-0.08 Kurtosis

-1.28 0Mean 1.05 D Median 1.22

~ Normal Distribution D Less Bins D More Bins Figure 20.

SU7 Soil Sample Statistics Summary Th-232 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 22 FSS Report Addendum May 2018

The individual analytical results for all SU7 soil samples and field duplicate measurements are presented in Table 5. Additionally, Table 5 includes SOF calculations for each isotope of interest versus its respective surface soil DCGL. To be conservative, isotopes of interest with reported activities less than O were assigned a value of O for the calculation.

A single elevated area sample was collected from SU7 and submitted for analysis with the corehole samples.1 The analytical result of this sample was above the surface DCGL for Th-232.

This sample and the detailed analysis of the gamma survey data prompted the elevated measurement investigation discussed in Section 2.3.

1 Field review of the gamma scans, described in Section 2.2.3, identified an area of elevated measurements. The sample was collected to confirm the presence of elevated material.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 23 FSS Report Addendum May 2018

~ bl 5 a e Date Net Sample ID Analyzed Weight 7001-SS-FS 9/27/2017 237 7002-SS-FS 9/27/2017 261 7003-SS-FS 9/27/2017 255.2 7004-SS-FS 9/27/2017 256.6 7005-SS-FS 9/27/2017 262.4 7005-SS-FD 10/4/2017 277.5 7006-SS-FS 9/27/2017 259.4 7007-SS-FS 9/28/2017 272.3 7008-SS-FS 9/28/2017 245.3 7009-SS-FS 9/28/2017 260.2 7010-SS-FS 9/28/2017 273.4 7011-SS-FS 9/28/2017 349.3 7012-SS-FS 9/29/2017 243.6 7013-SS-FS 9/29/2017 240 7014-SS-FS 9/29/2017 383.5 7015-SS-FS 9/29/2017 259.4 7016-SS-FS 9/29/2017 296.6 7017-SS-FS 10/2/2017 359.2 7018-SS-FS 10/2/2017 307 7019-SS-FS 10/2/2017 344.5 7020-SS-FS 10/2/2017 342.8 7021-SS-FS 10/2/2017 353.4 7022-SS-FS 10/2/2017 273.4 7023-SS-FS 10/2/2017 266 7024-SS-FS 10/2/2017

. 260.9 7025-SS-FS 10/2/2017 383.3 7026-SS-FS 10/2/2017 256 7027-SS-FS 10/2/2017 260.4 7028-SS-FS 10/3/2017 352.2 7029-SS-FS 10/3/2017 263.4 7030-SS-FS 10/4/2017 270.7 7030-SS-FD 10/4/2017 273.7 7031-SS-FS 10/4/2017 274.6 7032-SS-FS 10/4/2017 388.6 7-HS-SS-FS 9/13/2017 267.1 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 SU7 S *t S Ol L R Lt ampe esu s Moisture-Corrected Result Moisture U-235 U-238 12.8 0.17 0

17 0

12.28 10.4 0.07 2.76 10.7 0

7.66 11 0.15 11.74 11.2 0.10 0

11.5 0.06 4.13 14 0.25 0

13.7 0.19 2.04 14 0.25 12.78 13.4 0.14 14.57 1.1 0.1 0.7 12.1 0.09 0

19.3 0.47 0

0.9 0.1 0

11.3 0.18 0

4 0.1 0

0.8 0.04 0

1.7 0.13 0

3.4 0.13 0

0.8 0.13 1.37 0.3 0.1 0

8 0.21 1.95 16.3 0.08 0

18.2 0.13 2.75 1.6 0

0 14.5 0.23 5.07 13.5 0.14 0

0.7 0.12 12.41 11.7 0.05 6.73 13 0.08 0

11.8 0.09 2.16 13.8 0.13 2.7 0.4 0

0 7.2 4.3 57.66 wood.

Page 24 SOF Th-232 Am-241 1.38 0

1.51 0.02 1.3 0

1.66 0

2.04 0.42 0.95 0

1.72 0

2.06 0.03 1.39 0.22 2.29 0

1.36 0

0.56 0.05 0.55 0

1.05 0

0.07 0

1.14 0

0.25 0.24 0

0 0.15 0.08 0.09 0

0.22 0.1 0.19 0

1.98 0

1.46 0.07 1.32 0

0 0.11 1.33 0

0.86 0

0.28 0.2 1.68 0.01 1.56 0

1.99 0

0.94 0

0.26 0.06 32.21 0

FSS Report Addendum May 2018 0.38 0.45 0.36 0.47 0.59 0.26 0.48 0.56 0.39 0.66 0.42 0.16 0.15 0.29 0.02 0.31 0.07 0.00 0.04 0.03 0.07 0.05 0.54 0.40 0.37 0.00 0.38 0.23 0.12 0.48 0.42 0.54 0.26 0.07 8.95

Table 5.

SU7 Soil Sample Results Date Net Moisture-Corrected Result Sample ID Analyzed Weight Moisture SOF U-235 U-238 Th-232 Am-241 SU7 Mean 0.24 4.61 1.94 0.05 0.54 Standard Deviation 0.70 10.12 5.24 0.09 2.2.3 Gamma Scanning Results Gamma scanning was performed using the ScanPlot5M system, with a large volume ( ~4L),

spectroscopy-grade Nal detector, digital spectrometer, and a survey-grade GPS system configured on a push cart. Spectral data was acquired every second while the push cart moved at a survey speed of approximately 1 mps, on 1 m transects. Each data point is representative of an area of approximately 5 m2. The spectral data was processed in a manner similar to the in-situ static measurement data. Net photo peak count rates were determined for a variety of ROis for the isotopes of interest.

Two-dimensional, color-scale maps of the gross gamma, gross Am-241, gross U-235, and net Th-232 radiological count rates were generated and are provided in the sequential figures from Figure 21 to Figure 24.

The field assessment of the gamma survey data revealed a small area with elevated gamma measurements prompting the collection of a single soil sample labeled 7-HS-SS-FW. This sample was included with the other samples analyzed by the NFS NDA laboratory and is included in Table 5.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 25 FSS Report Addendum May 2018

Figure 21.

SU7 Gross Gamma Map (cps)

Figure 22.

SU7 Gross Am-241 Gamma Map (cps)

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 26 FSS Report Addendum May 2018

Figure 23.

Figure 24.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 G,oss U-23S Oet-l [No Aggr<!g4t>0n)

SU7 Gross U-235 Gamma fvTap (cps)

SU7 Net Th-232 Gamma fvTap (cps) wood.

Page 27 FSS Report Addendum May 2018

L 2.3 PHASE 2 INVESTIGATION Detailed analysis of the field data identified two small areas with elevated measurements (identified hereafter as Areas A and B). Area A was identified during field operations and was confirmed by the laboratory analysis of sample 7-HS-SS-FW. Both areas occur in surface drainage features (swales) that have been constructed to manage and facilitate surface water drainage on the North Site. Area A has manifestly higher gamma count rates. Area B was detected only after the scan data was processed and spatially mapped. The processed and compiled spectral scan data indicated that the elevated gamma signal is largely contri buted by gamma energies corresponding to Th-232.

A locally elevated measurement investigation plan was developed and included as Addendum 1 to the FSP in October 2017. These two small areas, labeled as A and B were both located on the border of SU7 and are comparable in size (Figure 25). Samples were collected in January/February 2018 from both areas.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 Figure 25.

wood.

Page 28 Areas A & B Net Th-232 Ot!t-1 (No Aggregation) 151.09 or MON!

FSS Report Addendum May 2018

2.3.1 Systematic Sampling Design The systematic sampling design is summarized here with the details provided in the FSP Addendum 0Jjood 2018). A systematic set of surface soil samples were collected in an areal pattern. The central point is positioned over the location of the observed highest gamma radiation count rate. Four samples were collected from each of the six concentric circles, with sample collection points chosen at every other radian and alternating on each circle, resulting in the collection of 25 samples for each area. The samples were numbered starting with 1 at the upper right corner of the largest circle and spiraling in counterclockwise to the center point labeled 25. Appendix A provides the GPS coordinates for the samples collected in Areas A and B.

R33m R 4 5m ---

--* -- T -* -* * * * -

- +

Figure 26.

Area Sampling Plan 2.3.2 Area A The Area A samples were collected, labeled, and submitted to the NFS NDA laboratory for analysis.

Samples were analyzed in February 2018 for U-235, U-238, Th-232, and Am-241 via gamma spectroscopy. Results were moisture-corrected and are provided in Table 6.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 29 FSS Report Addendum May 2018

i bl 6 a e A

AS *1 S rea Ol l R ampe esu ts Sample ID

% M oist.

MOISTURE-CORRECTED DATA (pCi/g)

U-235 U-238 Th-232 Am-241 AOl-N N 33-FS 13.3 0.13 0

a.so 0

A02-NE4S-FS 22.7 0.30 16.93 2.68 0.56 A03-EE33-FS 22 0.20 16.85 1.88 0.03 A04-SE45-FS 27.5 0.28 6.66 2.06 0.24 A05-SS33-FS 22.7 1.79 33.17 5.09 0

A06-SW45-FS 23.1 0.20 0

1.70 0

A07-WW33-FS 22.2 0.30 13.10 1.98 0.08 A08-NW45-FS 22.2 1.20 19.28 5.35 0

A09-NW22-FS 18.8 1.70 10.28 1.84 0

A10-NN15-FS 27.7 0.45 9.09 2.44 0

A10-NN15-FD 24.5 0.31 0

0.75 0.58 All-NE22-FS 10 0

2.59 0.90 0

A12-EE15-FS 24.7 0.61 3.88 3.29 0.87 A13-SE22-FS 22.7 0.67 0

5.63 0

A13-SE22-FD 23.2 0.59 14.00 6.52 0.16 A14-SS15-FS 11.2 1.10 25.63 2.08 0

A15-SW22-FS 26.2 0.51 1.29 3.02 0

A15-SW22-FD 24.9 0.18 5.80 1.99 0.14 A16-WW15-FS 11.1 0.16 8.70 1.11 0

A17-WW08-FS 12.7 1.55 6.11 1.17 0

A18-SW10-FS 12.4 0.84 17.89 2.00 0

A19-SS08-FS 16 1.45 22.80 1.65 0

A20-SE10-FS 21 1.10 20.65 6.99 0

.. 1 A21-EE08-FS 26.6 1.03 0

5.72 0

A22-NE10-FS 23.4 0.56 7.79 2.67 0

A23-NN08-FS 16.7 0.51 9.70 3.45 0

A24-NW10-FS 15.9 3.31 41.17 6.23 0

A25-NNOO-FS 19 5.77 70.95 48.88 0

The laboratory sample results were entered in conjunction with their spatial coordinates into GIS software, as shown in Figure 27, to allow for geospatially interpolation.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 30 FSS Report Addendum May 2018

e Figure 27.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0

---m:s======::::i10Fee, I Erwin, TN Survey Units 6 and 7 Survey Data Area A amec foste w r

Area A Interpolation wood.

Page 31 FSS Report Addendum May 2018

Evaluation of this figure produced an appropriate set of spatially weighted values. Using the area factors provided in Section 5.2.6 of the FSS Plan, DCGLemc were calculated for evaluation of the isotopes of interest. The evaluation shows that for all grids Am-241 (Table 7), U-235 (Table 8), and Th-232 (Table 9) are below the DCGLemc. The isotope contributions to each SOF were also calculated.

T, bl 7 a e A

A S ( /l W. ht d A 241 v'. l rea pa LO y etq, e m-a ues Length of MEAN Evaluation (pCi/g)

Grid (ft) 3

-0.02 5

-0.01 7

0.02 9

0.06 11 0.09 13 0.10 15 0.10 17 0.10 19 0.11 21 0.11 23 0.11 T, bl 8 a e Length of MEAN Evaluation (pCi/g)

Grid (ft) 3 3.34 5

2.34 7

1.71 9

1.32 11 1.07 13 0.90 15 0.78 17 0.70 19 0.64 21 0.60 23 0.56 NFS North Site-SU6 and SU? Surface Soil Characterization Revision 0 EMC Area EMC DCGL-EMC Am-241 (m2)

Area Am-241 Contributio Factor (pCi/g) n to SOF 1.00 9.54 213.32

-0.010%

2.32 8.36 186.91

-0.007%

4.55 7.43 166.08 0.011%

7.53 6.76 151.17 0.037%

11.24 6.27 140.18 0.058%

15.70 5.88 131.54 0.071%

20.90 5.57 124.56 0.079%

26.85 5.31 118.76 0.084%

33.54 5.05 112.92 0.090%

40.97 4.79 107.14 0.096%

49.15 4.57 102.14 0.102%

A A S t' ll W. ht d U 235 v'. l rea

>PO LO '.Y etg e a ues EMC Area EMC (m2)

Area Factor 1.00 5.8 2.32 3.84 4.55 2.76 7.53 2.15 11.24 1.82 15.70 1.67 20.90 1.55 26.85 1.46 33.54 1.40 40.97 1.35 49.15 1.32 wood.

Page 32 DCGL-EMC U-235 U-235 Contributio (pCi/g) n to SOF 24.00 13.92%

15.90 14.69%

11.42 14.99%

8.91 14.86%

7.51 14.21%

6.91 13.01%

6.43 12.18%

6.04 11.62%

5.78 11.14%

5.60 10.70%

5.45 10.36%

FSS Report Addendum May 2018

i bl 9 a e A

AS

. LL

~. h d Th 232 ~ l rea patw 1y e1g. te a ues Length of M EAN EMC Area EMC DCGL-EMC Th-232 Evaluation (pCi/g)

(m2)

Area Th-232 Contributi Grid (ft)

Factor (pCi/g) on to SOF 3

12.61 1.00 8.4 25.12 50.2%

5 6.65 2.32 4.92 14.71 45.2%

7 4.15 4.55 3.30 9.86 42.1%

9 2.88 7.53 2.48 7.41 38.8%

11 2.16 11.24 1.82 5.43 39.8%

13 1.73 15.70 1.67 4.99 34.6%

15 1.45 20.90 1.55 4.65 31.2%

17 1.26 26.85 1.46 4.37 28.9%

19 1.14 33.54 1.40 4.17 27.2%

21 1.06 40.97 1.35 4.05 26.1%

23 1.01 49.15 1.32 3.94 25.6%

The SOF contribution from Am-241, U-235, and Th-232 along with the combined SOF values for Area A were calculated and provided as Figure 28, and confirms the SOF score is less than unity (1.0).

Comparison to SOF Criteria Area-A 1.20

-.- combined...

-.-Th-232...

-.- Am-241...

-.- u-235...

1.00 --------------------- ----

0.80..

LL O 0.60 Vl..

0.40 0.20

0.00 1

Figure 28.

NFS North Site-SUS and SU7 Surface Soil Characterization Revision 0 10 Area (m2) t j

100 Area A SOF Comparison wood.

Page 33 FSS Report Addendum May 2018

To complete the SOF evaluation, the area and SU values were combined to ensure the SOF for the entire SU is less than unity, as shown in Table 10.

Table 10.

SUl & Area A SOF Evaluation Length of EMC Area EMC HS-A SUWAA Combined Evaluation (m2)

Factor**

SOF Score SOF Score SOF Score Decision Grid (ft) 3 1.00 5.8 0.64 0.04 0.68 PASS 5

2.32 3.84 0.60 0.04 0.64 PASS 7

4.55 2.76 0.57 0.04 0.61 PASS 9

7.53 2.15 0.54 0.04 0.58 PASS 11 11.24 1.82 0.54 0.04 0.58 PASS 13 15.70 1.67 0.48 0.04 0.52 PASS 15 20.90 1.55 0.43 0.04 0.47 PASS 17 26.85 1.46 0.41 0.04 0.45 PASS 19 33.54 1.40 0.38 0.04 0.42 PASS 21 40.97 1.35 0.37 0.04 0.41 PASS 23 49.15 1.32 0.36 0.04 0.40 PASS 2.3.3 Area B Area B was not identified during the field effort but was clearly seen during the formal data evaluation process. Samples from the elevated area were collected, labeled, and submitted to the NFS NOA laboratory for analysis. Samples were analyzed by the NFS NOA laboratory in February 2018 for U-235, U-238, Th 232, and Am-241 via gamma spectroscopy. Results we re moisture-corrected and are provided in Table 11.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 34 FSS Report Addendum May 2018

Table 11.

Area B Soil Sample Results Sample ID

% Moist.

MOISTURE-CORRECTED DATA (pCi/g)

U-235 U-238 Th-232 Am-241 B01-NN33-FS 24.3 0.35 5.36 1.51 2.36 B02-NE45-FS 24.8 0.20 12.90 2.12 0

B03-EE33-FS 29 0.13 0

1.25 0.57 B04-SE45-FS 26.5 0.22 0

1.04 0.32 B05-SS33-FS 23.8 0.27 1.65 1.47 0.35 B06-SW45-FS 23.9 0.29 4.57 1.19 0

B07-WW33-FS 26.8 0.16 8.30 1.18 0

B08-NW45-FS 18.6 0.10 14.82 1.99 0.15 B09-NW22-FS 24.7 0.29 0

1.67 0.12 B10-NN15-FS 23.5 0.45 0

2.07 2.02 B11-NE22-FS 31.6 0.35 19.69 2.35 1.35 B11-NE22-FD 27.1 0.21 3.44 1.75 0.44 B12-EE15-FS 26.7 1.43 0.96 8.77 16.48 B13-SE22-FS 24.8 0.26 0

2.05 1.04 B14-SS15-FS 17.3 0.23 3.85 2.19 0.18 B15-SW22-FS 23.6 0.65 6.11 2.61 5.01 B15-SW22-FD 22.2 0.56 0

3.02 6.53 B16-WW15-FS 24.7 0.28 17.45 1.72 1.07 B17-WW08-FS 26.4 0.65 10.72 3.21 5.18 B18-SW10-FS 40 1.03 0

5.67 12.51 B19-SS08-FS 26.2 1.81 0

10.32 31.49 B20-SE10-FS 25.5 0.46 0

2.22 1.35 B21-EE08-FS 50.6 1.01 0

6.42 18.66 B22-NE10-FS 29.8 1.19 0

5.65 10.07 B23-NN08-FS 24.6 0.82 19.05 3.93 7.47 B24-NW10-FS 25.9 0.16 0

1.21 0

B25-NNOO-FS 39.9 6.18 4.42 15.10 55.31 The laboratory sample results were entered in conjunction with their spatial coordinates into GIS software, as shown on Figure 29, to allow for geospatially interpolation.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 35 FSS Report Addendum May 2018

I Figure 29.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 l.~d 111 Ul $-,lff pC 8 Th 112 IMtfl>out.-1 s.,,t-pC 11 119' 2

Erwin, TN Survey Units 6 and 7 Survey Data Areas ter Area B Interpolation wood.

Page 36 FSS Report Addendum May 2018

Evaluation of this figure produced an appropriate set of spatially weighted values. Using the area factors provided in Section 5.2.6 of the FSS Plan, DCGLemc were calculated for evaluation of the isotopes of interest. The evaluation shows that for all grids Am-241 (Table 12), U-235 (Table 13),

and Th-232 (Table 14) are below the DCGLemc. The isotope contributions to each SOF were also calculated.

T bl 12 a e A

B S

. ll W. h d A 241 ~ l rea

,patw 'Y eig te m-a ues Length of MEAN Evaluation (pCi/g)

Grid (ft) 3 34.89 5

24.26 7

16.54 9

11.87 11 9.00 13 7.09 15 5.73 17 4.72 19 3.95 21 3.34 23 2.85 T bl 13 a e Length of MEAN Evaluation (pCi/g)

Grid (ft) 3 3.50 5

2.26 7

1.47 9

1.04 11 0.79 13 0.64 15 0.53 17 0.45 19 0.38 21 0.33 23 0.29 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 EMC Area EMC DCGL-EMC Am-241 (m2)

Area Am-241 Contributi Factor**

(pCi/g) on to SOF 1.00 9.54 213.32 16.357%

2.32 8.36 186.91 12.978%

4.55 7.43 166.08 9.960%

7.53 6.76 151.17 7.851%

11.24 6.27 140.18 6.417%

15.70 5.88 131.54 5.389%

20.90 5.57 124.56 4.600%

26.85 5.31 118.76 3.975%

33.54 5.05 112.92 3.496%

40.97 4.79 107.14 3.116%

49.15 4.57 102.14 2.786%

A B S t" ll W. h d U 235 ~ l rea

PO LOY eiq, te a ues EMC Area EMC (m2)

Factor**

1.00 5.8 2.32 3.84 4.55 2.76 7.53 2.15 11.24 1.82 15.70 1.67 20.90 1.55 26.85 1.46 33.54 1.40 40.97 1.35 49.15 1.32 wood.

Page 37 DCGL-EMC U-235 U-235 Contributi (pCi/g) on to SOF 24.00 14.57%

15.90 14.22%

11.42 12.85%

8.91 11.65%

7.51 10.58%

6.91 9.25%

6.43 8.23%

6.04 7.40%

5.78 6.64%

5.60 5.94%

5.45 5.36%

FSS Report Addendum May 2018

r: bl 14 a e A

8 S

. ll lM. h d Th 232 \\I'. l rea patw V eiq te a ues Length of EMC DCGL-EMC Th-232 MEAN EMC Area (MOD)

Evaluation (pCi/g)

(m2)

Area Th-232 Contribution Grid (ft)

Factor to SOF (pCi/g) 3 8.75 1.00 8.4 25.12 34.9%

5 6.28 2.32 4.92 14.71 42.7%

7 4.45 4.55 3.30 9.86 45.1%

9 3.33 7.53 2.48 7.41 44.9%

11 2.61 11.24 1.82 5.43 48.1%

13 2.10 15.70 1.67 4.99 42.0%

15 1.70 20.90 1.55 4.65 36.6%

17 1.38 26.85 1.46 4.37 31.7%

19 1.12 33.54 1.40 4.17 26.9%

21 0.91 40.97 1.35 4.05 22.5%

23 0.73 49.15 1.32 3.94 18.6%

The SOF contribution from Am-241, U-235, and Th-232 along with the combined SOF values for the area were calculated and provided as Figure 30, and confirms the SOF score for Area B is less than unity (1.0) 1.20 Comparison to SOF Criteria Area-B

-+- Combined...

-+-Th-232...

-+- Am-241..

-+- U-235...

1.00 -

0.80 u..

0 0.60 V) 0.40 0.20 0.00 NFS North Site-1 Figure 30.

SU6 and SU7 Surface Soil Characterization Revision 0 10 Area (m2)

Area 8 SOF Comparison wood.

Page 38 100 FSS Report Addendum May 2018

To complete the SOF evaluation, the area and SU7 values were combined to ensure the SOF for the entire SU is less than unity, as shown in Table 15.

Table 15.

Length of EMC Area EMC Evaluation (m2)

Factor**

Grid (ft) 3 1.00 5.8 5

2.32 3.84 7

4.55 2.76 9

7.53 2.15 11 11.24 1.82 13 15.70 1.67 15 20.90 1.55 17 26.85 1.46 19 33.54 1.40 21 40.97 1.35 23 49.15 1.32 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 SU7 & Area B SOF Evaluation HS-B SUWAA SOF Score SOF Score 65.8%

0.04 69.9%

0.04 67.9%

0.04 64.4%

0.04 65.1%

0.04 56.7%

0.04 49.4%

0.04 43.1%

0.04 37.1%

0.04 31.5%

0.04 26.7%

0.04 wood.

Page 39 Combined SOF Score Decision 0.70 PASS 0.74 PASS 0.72 PASS 0.68 PASS 0.69 PASS 0.61 PASS 0.53 PASS 0.47 PASS 0.41 PASS 0.36 PASS 0.31 PASS FSS Report Addendum May 2018

3 QUALITY CONTROL 3.1 SCANPLOfiM Numerous quality control measures were implemented during the surface investigation of SU6 and SU7. The ScanPlot5M push cart platform underwent routine spectral alignment and source response checks (SRCs). Checks include three key control measures to ensure the quality of the data including routine spectral alignments, routine SRCs, and analysis and reporting of K-40 (a naturally-occurring radioactive element).

Spectral alignment was performed at the beginning of each shift of work and throughout the day at least every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. It was performed after any delay or break in survey work. The energy spectrum was aligned so that the K-40 peak and Cesium-137 (Cs-137) peak (from a check source) were within +/- 2 (+/- <0.5%) channels of their target channels, as established during the commissioning and calibration of each detector.

The detectors were subject to SRCs to a Cs-137 button source on the same or greater frequency as the spectral alignments. The spectrum from the 1-minute SRCs was processed in the same manner as survey data; ROis were analyzed, and net photopeak count rates were calculated. The SRCs were required to be within 20% of the mean or target count rate in order to continue survey activities.

The last quality control measure utilized for the survey was the collection and analysis of the K-40 concentrations throughout the survey units. K-40 analysis provides a number of quality assurance benefits for gamma scanning. K-40 provides a radioactive signal when the real isotopes of interest may not be present in a survey area. Analysis of K-40 can also provide comparisons across different measurements such as scanning, in-situ, and soil sample analysis. The K-40 scanning results are presented graphically in Figure 31 and Figure 32 and are provided to qualitatively demonstrate the sensitivity and spatial resolution produced during the surface scan of SU6 and SU7.

It should be noted that K-40 concentrations vary naturally across many different materials such as soil, rock, and vegetation. Elevated K-40 concentrations are not an indication of contamination or a need for remediation. Changing K-40 concentrations can produce a number of undesirable effects on gross gamma scans such as false positives or improper application of background values.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 40 FSS Report Addendum May 2018

~ *;-

\\

/; i

',,. t

, :/'~

~

\\.t t'i,.... :a {

,. \\,,

., ~*

,.... ~ Na

/

~

~>'::f.! ;

,:~

rt'-

1. -~~-

.'. ' t'

't

,I'*

Figure 31.

Figure 32.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 SU6 K-40 Gamma Map (cps)

SU7 K-40 Gamma fv1ap (cps) wood.

Page 41 FSS Report Addendum May 2018

3.2 LABORATORY ANALYSIS Field duplicate samples were collected during both sampling events. The duplicate samples were compared, and the duplicate error ratios (DER) for all samples were less than the established DER control limit value of 2.0.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 42 FSS Report Addendum May 2018

4 CONCLUSION The surface scans show that the concentrations of the isotopes of concern were uniform across SU6. The in-situ measurements also show that the concentrations of U-235, U-238, Am-241, and Th-232 were stable across the survey unit. The soil samples collected were below the applicable surface DCGL, and the SOFs was less than 1.0. The surface of SU6 meets the established requirements for unrestricted release (NFS, 2006).

The surface scans show that the concentrations of the isotopes of concern were not uniform across SU7. Two areas with elevated gamma radiation levels were identified and investigated.

The in-situ measurements and soil sample results from the corehole samples were below the applicable surface DCGLw, and the SOFs were all less than 1.0. The two elevated areas underwent additional sampling and data analysis. Based on this additional analysis, the two areas designated as A and B do not exceed the DCGLemc. The surface of SU7 meets the established requirements for unrestricted release (NFS, 2006).

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 43 FSS Report Addendum May 2018

5 ACRONYMS Am.............................. americium DCGL......................... derived concentration guideline level DCGLw...................... derived concentration guideline level for the average (or median) concentration in the survey unit DCGLEMc................... elevated measurement comparison concentration guideline level DP............................... Decommissioning Plan DER............................ Duplicate Error Ratio EPA............................. U.S. Environmental Protection Agency FSP............................. Field Sampling Plan FSS............................. Final Status Survey ft.................................. foot GPS............................ Global Positioning System L.................................. liter m................................. meter m2.***.******.*.....*.*.*..*.*... square meter mps............................ meters per second N DA........................... non-destructive analysis NFS............................ BWXT Nuclear Fuel Services Inc.

NRC............................ U.S. Nuclear Regulatory Commission pCi/g......................... picocuries per gram Pu............................... plutonium SOF............................ sum of fraction Th................................ thorium U................................. uranium NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 44 FSS Report Addendum May 2018

6 REFERENCES AmecFW 2017 NFS North Site Surface Soil Survey Project Field Sampling Plan, Revision 1, October 2017.

ProUCL Version 5.1.

EPA 2016 NFS 2006 Nuclear Fuel Services, Inc., North Site Decommissioning Plan, Revision 3, Nuclear Fuel Services, Inc., Erwin, Tennessee, March 2006.

NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page 45 FSS Report Addendum May 2018

APPENDIX A Area A and B Sample Locations NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 wood.

Page A-1 FSS Report Addendum May 2018

T bl A 1 a e -

Sample ID Easting A01-NN33-FS 371245.8598 A02-NE45-FS 371249.0383 A03-EE33-FS 371249.5051 A04-SE45-FS 371249.4283 A05-SS33-FS 371246.4833 A06-SW45-FS 371243.5063 A07-WW33-FS 371242.8364 A08-NW45-FS 371243.0766 A09-NW22-FS 371244.4823 A10-NN15-FS 371246.0136 A10-NN15-FD 371246.0136 All-NE22-FS 371247.5467 A12-EE15-FS 371247.7038 A13-SE22-FS 371247.8609 A13-SE22-FD 371247.8609 A14-SS15-FS 371246.3295 A15-SW22-FS 371244.7964 A15-SW22-FD 371244.7964 A16-WW15-FS 371244.6393 Al 7-WW08-FS 371245.3592 A18-SW10-FS 371245.5294 A19-SS08-FS 371246.2493 A20-SE10-FS 371246.9724 A21-EE08-FS 371246.9822 A22-NE10-FS 371246.8121 A23-NN08-FS 371246.0922 A24-NW10-FS 371245.3707 A25-NNOO-FS 371246.1711 NFS North Site-SU6 and SU? Surface Soil Characterization Revision 0 A

AS reo l L t

amp e oco wns Northing Date Analyzed Net Weight (g) 3999564.659 2/2/18 3999564.745 2/2/18 3999561.609 2/2/18 3999558.226 2/2/18 3999558.103 2/2/18 3999557.637 2/2/18 3999561.042 2/2/18 3999564.522 2/2/18 3999562.793 2/2/18 3999562.881 2/5/18 3999562.881 2/5/18 3999563.081 2/5/18 3999561.525 2/5/18 3999559.969 2/5/18 3999559.969 2/5/18 3999559.881 2/5/18 3999559.682 2/6/18 3999559.682 2/6/18 3999561.237 2/6/18 3999561.227 2/6/18 3999560.558 2/6/18 3999560.548 2/6/18 3999560.759 2/6/18 3999561.425 2/6/18 3999562.093 2/6/18 3999562.103 2/6/18 3999562.003 2/6/18 3999561.348 2/6/18 wood.

Page A-2 282.7 264.2 323.7 340.6 338.5 296.1 336.5 288.8 345 282.1 303.3 373.9 293.6 320.1 280.2 318.4 319.9 279.7 364.2 364.9 360.4 356.4 296.8 292.5 305.2 300.5 282.1 330.6 FSS Report Addendum May 2018

i bl A 2 a e -

Sample ID Easting B01-NN33-FS 371228.3421 B02-NE45-FS 371231.5906 B03-EE33-FS 371231.829 B04-SE45-FS 371231.8309 B05-SS33-FS 371228.649 B06-SW45-FS 371225.4582 B07-WW33-FS 371225.2199 B08-NW45-FS 371225.2179 B09-NW22-FS 371226.9079 B10-NN15-FS 371228.4678 B11-NE22-FS 371230.0234 B11-NE22-FD 371230.0234 B12-EE15-FS 371230.0265 B13-SE22-FS 371230.1409 B14-SS15-FS 371228.5811 B15-SW22-FS 371227.0254 B15-SW22-FD 371227.0254 B16-WW15-FS 371227.0223 B17-WW08-FS 371227.7233 B18-SW10-FS 371227.843 B19-SS08-FS 371228.5546 B20-SE10-FS 371229.2592 B21-EE08-FS 371229.3255 B22-NE10-FS 371229.2058 B23-NN08-FS 371228.4942 B24-NW10-FS 371227.7896 B25-NNOO-FS 371228.5373 NFS North Site-SU6 and SU7 Surface Soil Characterization Revision 0 A

BS rea l L

(

ampe oca tons Northing 3999619.239 3999619.244 3999616.076 3999612.899 3999612.662 3999612.66 3999615.828 3999619.005 3999617.445 3999617.447 3999617.561 3999617.561 3999616.008 3999614.459 3999614.456 3999614.343 3999614.343 3999615.896 3999615.922 3999615.22 3999615.154 3999615.273 3999615.982 3999616.683 3999616.75 3999616.63 3999615.907 wood.

Page A-3 Date Analyzed Net Weight (g) 2/7 /18 2/7 /18 2/7/18 2/7 /18 2/7 /18 2/7 /18 2/7/18 2/7/18 2/7/18 2/7 /18 2/8/18 2/8/18 2/8/18 2/8/18 2/8/18 2/8/18 2/8/18 2/8/18 2/8/18 2/8/18 2/9/18 2/9/18 2/9/18 2/9/18 2/9/18 2/9/18 2/9/18 310.7 371.5 388 334.9 358.6 342.4 369.6 330 336.5 355.4 359.7 366.7 382.1 337.7 320.6 301.1 330.4 352.6 361.8 397.6 361.8 332.8 375.1 367.9 385.4 347.5 380.9 FSS Report Addendum May 2018

ML18177A202

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