ML21027A163

Oak Ridge Institute for Science and Education (Orise), Ltr Dated January 8, 2021 W/Enclosure, Unc, Inc., Naval Final Confirmatory Survey Report

ML21027A163
Person / Time
Site:	07000371
Issue date:	01/08/2021
From:	Altic N Oak Ridge Institute for Science & Education
To:	Bailey O Division of Nuclear Materials Safety I
References
Download: ML21027A163 (59)

Text

January 8, 2021 Ms. Orysia Masnyk Bailey U.S. Nuclear Regulatory Commission Division of Nuclear Materials Safety Decommissioning Branch 2100 Renaissance Boulevard Suite 100 King of Prussia, PA 19406

SUBJECT:

CONTRACT NO. DE-SC0014664 INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE FORMER UNC NAVAL PRODUCTS FACILITY NEW HAVEN, CONNECTICUT DOCKET NO. 07000371; RFTA NO.19-006; DCN: 5340-SR-01-0

Dear Ms. Bailey:

The Oak Ridge Institute for Science and Education (ORISE) is pleased to provide the enclosed final report detailing the confirmatory survey activities for the 3H/6H Tract building excavation and associated areas at the United Nuclear Corporation (UNC) Naval Products facility in New Haven, Connecticut. The U.S. Nuclear Regulatory Commissions (NRCs) comments on the draft report were addressed in this final version.

Please contact me at 865.574.6273 or Erika Bailey at 865.576.6659 if you have any comments or concerns.

Sincerely, Nick A. Altic, CHP Health Physicist/Project Manager ORISE NAA:jlc Attachment Electronic distribution: K. Conway, NRC E. Bailey, ORISE D. Hagemeyer, ORISE Z. Cruz Perez, NRC File/5340 100 ORAU Way

• Oak Ridge

• TN 37830

• orise.orau.gov

THIS PAGE INTENTIONALLY LEFT BLANK.

INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE FORMER UNC NAVAL PRODUCTS FACILITY NEW HAVEN, CONNECTICUT Prepared by:

E. N. Bailey FINAL REPORT Prepared for the:

U.S. Nuclear Regulatory Commission January 2021 Further dissemination authorized to NRC only; other requests shall be approved by the originating facility or higher NRC programmatic authority.

This document was prepared for the U.S. Nuclear Regulatory Commission by the Oak Ridge Institute for Science and Education (ORISE) through interagency agreement number 31310018N0014 with the U.S. Department of Energy (DOE). ORISE is managed by Oak Ridge Associated Universities under DOE contract number DE-SC0014664.

ORAU provides innovative scientific and technical solutions to advance research and education, protect public health and the environment and strengthen national security. Through specialized teams of experts, unique laboratory capabilities and access to a consortium of more than 100 major Ph.D.-granting institutions, ORAU works with federal, state, local and commercial customers to advance national priorities and serve the public interest. A 501(c) (3) nonprofit corporation and federal contractor, ORAU manages the Oak Ridge Institute for Science and Education (ORISE) for the U.S. Department of Energy (DOE). Learn more about ORAU at www.orau.org.

NOTICES The opinions expressed herein do not necessarily reflect the opinions of the sponsoring institutions of Oak Ridge Associated Universities.

This report was prepared as an account of work sponsored by the United States Government.

Neither the United States Government nor the U.S. Department of Energy, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe on privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, mark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement or recommendation, or favor by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof.

INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE FORMER UNC NAVAL PRODUCTS FACILITY NEW HAVEN, CONNECTICUT Prepared by: Date: 1/8/2021 E. N. Bailey, Survey and Technical Projects Group Manager ORISE Prepared by: Date: 1/8/2021 N. A. Altic, CHP, Health Physicist/Project Manager ORISE Reviewed by: Date: 1/8/2021 P. H. Benton, Quality Manager ORISE Reviewed by: Date: 1/8/2021 W. F. Smith, Senior Chemist ORISE Reviewed and approved for release by: Date: 1/8/2021 D. A. Hagemeyer, Program Director ORISE FINAL REPORT JANUARY 2021 UNC Naval Confirmatory Survey Report i 5340-SR-01-0

CONTENTS Figures ................................................................................................................................................................ iv Tables .................................................................................................................................................................. iv Abbreviations and Acronyms List ................................................................................................................... v Executive Summary .......................................................................................................................................... vi

1. Introduction ............................................................................................................................................... 1

2. Site Description ......................................................................................................................................... 2

3. Data Quality Objectives ........................................................................................................................... 4 3.1 State the Problem .............................................................................................................................. 4 3.2 Identify the Decision/Objective ..................................................................................................... 4 3.3 Identify Inputs to the Decision/Objective.................................................................................... 6 3.3.1 Radionuclides of Concern and Contaminants of Concern ................................................. 6 3.4 Define the Study Boundaries ........................................................................................................... 6 3.5 Develop a Decision Rule.................................................................................................................. 7 3.5.1 PSQ1: Confirmatory Sample Concentrations ....................................................................... 7 3.5.2 PSQ2: Survey Unit Classification ........................................................................................... 8 3.6 Specify Limits on Decision Errors ................................................................................................. 8 3.7 Optimize the Design for Obtaining Data...................................................................................... 9

4. Procedures ................................................................................................................................................. 9 4.1 Reference System ............................................................................................................................10 4.2 Surface Scans....................................................................................................................................10 4.3 Measurement/Sampling Locations...............................................................................................10 4.3.1 Ranked Set Sampling ..............................................................................................................11 4.4 Soil Sampling....................................................................................................................................12 4.5 Miscellaneous Samples ...................................................................................................................12

5. Sample Analysis and Data Interpretation ............................................................................................13

6. Findings and Results...............................................................................................................................14 6.1 Surface Scans....................................................................................................................................14 6.2 Radionuclide Concentrations in Soil and Miscellaneous Samples ...........................................17

7. Summary and Conclusions ....................................................................................................................19

8. References ................................................................................................................................................21 UNC Naval Confirmatory Survey Report ii 5340-SR-01-0

APPENDIX A: FIGURES APPENDIX B: TABLES APPENDIX C: MAJOR INSTRUMENTATION APPENDIX D: SURVEY AND ANALYTICAL PROCEDURES UNC Naval Confirmatory Survey Report iii 5340-SR-01-0

FIGURES Figure 2.1. Aerial View of UNC Naval Products Facility ............................................................................ 3 Figure 6.1. Q-plots for Confirmatory Gamma Walkover Surveys ...........................................................15 Figure 6.2. Piping NaI Gamma Response Depth Profile ..........................................................................17 Figure 6.3. Q-plots for ORISE Confirmatory Survey Soil Sample Uranium Concentrations..............19 TABLES Table 3.1. Confirmatory Survey Decision Process ....................................................................................... 5 Table 3.2. Total Uranium Scan MDC for 2-inch by 2-inch NaI Detector ............................................... 9 Table 4.1. Summary of Volumetric Samples Collected ..............................................................................12 Table 6.1. Gamma Walkover Summary Statistics .......................................................................................14 Table 6.2. Summary of Piping Assessed, Scan Ranges ...............................................................................16 Table 6.3. Summary Statistics for Radionuclide Concentrations in Random Soil Samples ..................18 UNC Naval Confirmatory Survey Report iv 5340-SR-01-0

ABBREVIATIONS AND ACRONYMS LIST AA alternative action CB catch basin CFR Code of Federal Regulations cm centimeter(s) cpm counts per minute CU confirmatory unit DCGL derived concentration guideline level DCGLU-tot total uranium derived concentration guideline level DQO data quality objective EPA U.S. Environmental Protection Agency EU enriched uranium FSS final status survey GE General Electric Company GPS global positioning system m meter(s)

MDC minimum detectable concentration mrem/yr millirem per year NaI[Tl] thallium-doped sodium iodide NRC U.S. Nuclear Regulatory Commission ORAU Oak Ridge Associated Universities ORISE Oak Ridge Institute for Science and Education pCi/g picocurie per gram PSQs principal study questions Q quantile REAL Radiological and Environmental Analytical Laboratory ROCs radionuclides of concern RSS ranked set sampling SNM special nuclear material SU survey unit TEDE total effective dose equivalent UNC United Nuclear Corporation VSP Visual Sample Plan UNC Naval Confirmatory Survey Report v 5340-SR-01-0

INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE FORMER UNC NAVAL PRODUCTS FACILITY, NEW HAVEN, CONNECTICUT EXECUTIVE

SUMMARY

The United Nuclear Corporation (UNC) holds a special nuclear material (SNM) license, SNM-368, managed by the U.S. Nuclear Regulatory Commission (NRC). The SNM license authorized the possession and use of highly-enriched uranium and later source material, including natural uranium, depleted uranium, and thorium for research and nuclear fuel fabrication. The UNC site is located in New Haven, Connecticut. UNC operated the facility from 1961 to 1976. Buildings 3H and 6H were part of a larger nuclear fuel complex, referred to as the H-Tract (Arcadis 2019).

In 1974, UNC announced the closing of the H-Tract facility and transferred their equipment and inventory of radioactive materials from the New Haven location to the Montville, Connecticut location. Final surveys of the New Haven facility were completed in February 1976, and NRC subsequently released the site for unrestricted use in accordance with the existing release criteria at the time. License SNM-368 was amended in 1976 to remove the New Haven facility from the license. NRCs guidance and criteria for release for unrestricted use, at that time, was Regulatory Guide 1.86 (NRC 1974) and Guidelines for Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses for Byproduct, Source, or Special Nuclear Material (NRC 1973).

From 1989 to 1990, NRC initiated a Terminated Sites Review Project to ensure that formerly licensed facilities were terminated in accordance with current NRC criteria for release for unrestricted use. As part of this program, license SNM-368 was identified as a site that required additional review since final radiological survey records were either incomplete or inadequate. A radiological survey was conducted in 1996 using the release criteria in the 1981 Branch Technical Position Disposal or Onsite Storage of Thorium or Uranium Wastes from Past Operations (NRC 1981). Results of the survey indicated that residual enriched uranium (EU) exceeded the release criteria of 30 picocuries per gram (pCi/g) established in 46 CFR 52061 (NRC 1981) in several areas of the site.

In 1997, the site was acquired by General Electric Company. A final site cleanup plan was submitted in 2019 (Arcadis 2019). NRC requested that Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities at the former UNC Naval Facility with a focus on excavated areas under the former 3H/6H building and Argyle Street. ORISE performed UNC Naval Confirmatory Survey Report vi 5340-SR-01-0

confirmatory activities during the period of October 6-8, 2020. Confirmatory survey activities included gamma walkover scanning of the entire site, gamma direct measurements, soil sampling, and gamma scanning of catch basins and accessible piping. A total of 32 soil samples were collected across all confirmatory units: 27 random samples and 5 judgmental samples. All confirmatory samples had uranium concentrations less than the applicable release criterion (DCGLU-tot).

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1. INTRODUCTION The Atomic Energy Commission (later the U.S. Nuclear Regulatory Commission [NRC]) issued a special nuclear material (SNM) license, SNM-368, to Olin Mathieson Chemical Corporation Winchester Western Division in 1960 for fabrication and manufacturing of reactor fuel components for the Naval Reactors Program in New Haven, Connecticut. In 1961, Olin transferred the facility and license to United NuclearFuels Division, which became United Nuclear Corporation (UNC).

The SNM license authorized possession and use of highly-enriched uranium and later source material, including natural uranium, depleted uranium, and thorium for research and nuclear fuel fabrication. UNC operated the facility from 1961 to 1976. Buildings 3H and 6H were part of a larger nuclear fuel complex, referred to as the H-Tract (Arcadis 2019).

In 1974, UNC announced the closing of the H-Tract facility and transferred their equipment and inventory of radioactive materials from the New Haven location to the Montville, Connecticut location. Final surveys of the New Haven facility were completed in February 1976, and NRC subsequently released the site for unrestricted use in accordance with the existing release criteria at the time. License SNM-368 was amended in 1976 to remove the New Haven facility from the license. NRCs guidance and criteria for release for unrestricted use, at that time, was Regulatory Guide 1.86 (NRC 1974) and Guidelines for Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses for Byproduct, Source, or Special Nuclear Material (NRC 1973).

From 1989 to 1990, NRC initiated a Terminated Sites Review Project to ensure that formerly licensed facilities were terminated in accordance with current NRC criteria for release for unrestricted use. As part of this program, License No. SNM-368 was identified as a site that required additional review since final radiological survey records were either incomplete or inadequate. A radiological survey of the subsurface soils was conducted in 1996 using the release criteria in the 1981 Branch Technical Position Disposal or Onsite Storage of Thorium or Uranium Wastes from Past Operations (NRC 1981). Results of the survey indicated that residual enriched uranium (EU), in certain subsurface/subfloor soil samples collected from inside the building and connected inactive sewer system, exceeded the release criteria of 30 picocuries per gram (pCi/g) established in 46 CFR 52061 (NRC 1981). These contaminated areas were documented in an NRC inspection report (NRC 1996) and in Radiological Scoping Survey of Buildings 3H and 6H at the Former UNC H-Tract Facility, New Haven, Connecticut (ORISE 1997).

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In 1997, the site was acquired by General Electric Company (GE). A characterization report was completed in 2003 followed by a decontamination and decommissioning plan in 2005. A final status survey (FSS) plan was developed and submitted to NRC in 2006 to describe the surveys performed to confirm the removal of soil with total uranium concentrations greater than 30 pCi/g (Cabrera 2018). In 2013, NRC accepted an addendum to the decommissioning plan to use dose-based release criteria (derived concentration guideline levels [DCGLs]) that meet the state of Connecticuts dose standard (19 millirem per year [mrem/yr]). Subsequent investigations of the soil under the 3H/6H building did not find widespread contamination. It was determined that contamination most likely was present under drainage holes in the south trench and in a utility trench that runs the length of the building. A survey of the floor surfaces, portions of the walls, and other interior building surfaces (e.g., lamps, crossbeams) was conducted and reported in 2018 (Arcadis 2019).

Based on the history and characterization studies, it was decided to raze the 3H/6H tract building and remove the debris and a portion of the underlying soil. A cleanup plan was submitted in 2019 for the work (Arcadis 2019). NRC has requested that Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities at the former UNC Naval Facility with a focus on excavated areas under the former 3H/6H building and Argyle Street. NRC will use the confirmatory survey data for their decision making.

2. SITE DESCRIPTION The UNC H-Tract site is located at 71 Shelton Avenue in New Haven, Connecticut, and consists of a contiguous building (3H/6H) connected to an inactive sewer system that traverses an adjacent private property line. The building is adjacent to Argyle Street to the south. Figure 2.1 provides an aerial view of the site. The approximate total footprint of the 3H/6H building is 5,000 square meters (m2). Figure A.1 in Appendix A provides key features of the former 3H/6H building, including the South Trench, the sewer line, and manhole locations (Arcadis 2019). The UNC Naval Site was composed of several other buildings, which were demolished prior to 1990. Three of these buildings are identified as Building 9H, 10H, and 11Hand are also depicted in Figure A.1.

Radiological operations were conducted in the basements of these buildings. However, historical information related to these operations was not identified in site decommissioning documents.

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Figure 2.1. Aerial View of UNC Naval Products Facility Deconstruction of Buildings 3H/6H occurred prior to the ORISE confirmatory survey and involved the complete removal of the above-grade portion of buildings and partial removal of the at-grade and subslab features. The at-grade and subslab portions include slabs, trenches to full depth, interior and perimeter foundation walls to a depth of approximately 0.3 m below slab bottom, and approximately 0.3 m of soil from underneath the finished slabs and trenches. Above-grade portions of Buildings 9H/10H/11H were demolished, prior to the decommissioning efforts of Buildings 3H/6H, and the basement portions were backfilled.

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3. DATA QUALITY OBJECTIVES The data quality objectives (DQOs) described herein are consistent with the Guidance on Systematic Planning Using the Data Quality Objectives Process (EPA 2006) and provide a formalized method for planning radiation surveys, improving survey efficiency and effectiveness, and ensuring that the type, quality, and quantity of data collected are adequate for the intended decision applications. The seven steps in the DQO process are outlined below:

1. State the problem.

2. Identify the decision.

3. Identify inputs to the decision.

4. Define the study boundaries.

5. Develop a decision rule.

6. Specify limits on decision errors.

7. Optimize the design for obtaining data.

3.1 STATE THE PROBLEM The first step in the DQO process defines the problem that necessitates the study, identifies the planning team, and examines the project budget and schedule. A FSS was performed at the site to demonstrate that residual contamination levels do not result in a dose that exceeds NRC decommissioning criteria. NRC staff will review the FSS data submittal to evaluate the adequacy and accuracy of the FSS survey relative to the decommissioning approved end-point criteria. To support this effort, NRC requested that ORISE perform confirmatory surveys to generate independent radiological data to assist them in evaluating FSS results for the former UNC Naval site. Therefore, the problem statement was as follows:

Confirmatory surveys are necessary to generate independent radiological data to assist NRC with their assessment and determination of the adequacy of FSS results used for demonstrating compliance with the release criteria.

3.2 IDENTIFY THE DECISION/OBJECTIVE The second step in the DQO process identified the principal study questions (PSQs) and alternative actions (AAs), developed a decision statement, and organized multiple decisions, as appropriate.

This was done by specifying AAs that could result from a yes response to the PSQs and UNC Naval Confirmatory Survey Report 4 5340-SR-01-0

combining the PSQs and AAs into a decision statement. Given that the problem statement introduced in Section 3.1 is fairly broad, multiple PSQs arise. PSQs, AAs, and combined decision statements are presented in Table 3.1.

Table 3.1. Confirmatory Survey Decision Process Principal Study Questions Alternative Actions Yes:

Compile confirmatory data and report results to NRC for their decision making. Provide independent interpretation that confirmatory field surveys did not identify anomalous areas of residual radioactivity and PSQ1: Are residual radioactivity quantitative field and laboratory data satisfied concentrations within the former UNC NRC-approved decommissioning criteria.

Naval site below applicable limits?

No:

Compile confirmatory data and report results to NRC for their decision making. Provide independent interpretation of confirmatory survey results identifying any anomalous field or laboratory data.

Yes:

Confirmatory results support the classification of the FSS SUs. Compile confirmatory survey data and PSQ2: Do the confirmatory results present results to NRC for their decision making.

support the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) classification of the FSS No:

survey units (SUs)? Confirmatory results do not support the classification of the FSS SUs. Summarize the discrepancies and provide technical comments to NRC for their decision making.

Decision Statements Determine if radionuclide concentrations in confirmatory survey samples exceed the applicable limits.

Determine if confirmatory survey results support the sites MARSSIM classification of the FSS SUs.

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3.3 IDENTIFY INPUTS TO THE DECISION/OBJECTIVE The third step in the DQO process identified both the information needed and the sources of this information, determined the basis for action levels, and identifies sampling and analytical methods that will meet data requirements. For this effort, information inputs included the following:

• Site specific DCGLs, further discussed in subsection 3.3.1

• ORISE confirmatory surface scans

• ORISE volumetric sample analytical results 3.3.1 Radionuclides of Concern and Contaminants of Concern The primary radionuclides of concern (ROCs) for the UNC facility are those associated with EU (i.e., uranium-234, uranium-235, and uranium-238). UNC has developed site-specific DCGLs that correspond to a residual radioactive contamination level, which could result in a total effective dose equivalent (TEDE) of 19 mrem/yr. A TEDE of 19 mrem/yr corresponds to the state of Connecticuts dose criterion (AAA 2008). Rather than demonstrating compliance with the DCGL for the individual isotopes of uranium, NRC approved the use of a total uranium DCGL (DCGLU-tot). The DCGLU-tot was calculated assuming a U-235 assay of 93% (by U-235 mass),

resulting in a value of 435 pCi/g total uranium.

Per Section 6.5 of the sites cleanup plan, all soil sample concentrations will be directly compared to DCGLU-tot and any exceedances will be cause for additional remediation (Arcadis 2019). As such, the total uranium DCGL was treated as a not-to-exceed value, i.e., an elevated measurement comparison will not be performed.

3.4 DEFINE THE STUDY BOUNDARIES The fourth step in the DQO process defined target populations and spatial boundaries, determined the timeframe for collecting data and making decisions, addressed practical constraints, and determined the smallest subpopulations, area, volume, and time for which separate decisions are made.

Areas of the New Haven site that were targeted for confirmatory survey activities were the Building 3H/6H Tract excavation (prior to backfill), Argyle Street sewer, laydown area, storm water system, former Building 9H/10H/11H footprint, and the haul road.

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NRC staff prioritized areas below the former 3H/6H Tract building, prior to backfill and the storm water system. ORISE focused on these priority areas first and then investigated other areas with the greatest potential for residual contamination, as directed by NRC. A portion of the storm water system was removed by the site prior to the confirmatory survey. Storm water piping investigated by ORISE was selected by visual identification of available access points during a walkdown with NRC staff prior to conducting confirmatory survey activitieswith the exception of piping containing visible asbestos material. Additionally, the storm water piping was caved in at many of the identified access location (most locations had less than 1 m of piping available for the survey).

Individual survey units (SUs) were combined into larger confirmatory units (CUs) for confirmatory survey purposes: CU1 is the Building 3H footprint, CU2 is the Building 6H center footprint, CU3 is the Building 6H west footprint, and CU4 is the balance of the site. Figure A.2 in Appendix A depicts the CU boundaries. Storm water piping was investigated as part of the CU in which it was located.

3.5 DEVELOP A DECISION RULE The fifth step in the DQO process specified appropriate population parameters (e.g., mean, median), evaluated action levels relative to the appropriate detection limits, and developed an ifthen decision rule statement. Multiple PSQs were introduced in Table 3.1; therefore, multiple decision rules arose. The first PSQ relates to whether the residual radioactivity concentrations are below applicable limits with the second PSQ confirming the appropriateness of the SU classification. Decision rules for each PSQ are discussed below.

3.5.1 PSQ1: Confirmatory Sample Concentrations Confirmatory survey samples were collected to determine if residual radioactivity concentrations were below applicable limits to support NRC staffs determination that the FSS results are appropriate for the intended use. The general confirmatory survey approach to support this determination focused on collecting systematic data from specific survey areas and covering the majority of the site with qualitative investigations (i.e., surface scans). Two types of confirmatory samples were collected as part of this study: judgmental and random. Judgmental samples were collected based on on-site investigations, such as gamma walkover surveys, to evaluate discrete locations of potential contamination. Random samples were collected from CUs 1, 2, and 3 to provide NRC with an unbiased estimate of the mean radionuclide concentration. Because the ORISE field crew had access to the majority of the site and the surface scans were sufficient to UNC Naval Confirmatory Survey Report 7 5340-SR-01-0

identify residual radioactivity above the DCGL, surface scans served the basis for concluding residual radioactivity in CU4 was less than the allowable limit. The investigation level for the surface scans was an instrument response distinguishable from background.

The decision rule addressing PSQ1 was stated as:

If each individual confirmatory survey sample result is below the applicable limit (DCGLU-tot), then conclude that the confirmatory survey results satisfy the NRC-approved decommissioning criteria; otherwise, perform further evaluation(s) and provide technical comments/recommendations to NRC for their evaluation and decision making.

3.5.2 PSQ2: Survey Unit Classification The intent of assessing the classification of the survey areas as part of the confirmatory survey process based on the requirements outlined in the sites cleanup plan (Arcadis 2019), would primarily relate to Class 2 and Class 3 survey areas as well as non-impacted areas because a Class 1 SU will not receive a higher classification. However, this confirmatory action was not necessary as the final status survey plan deemed the entire site as impacted and all survey units were classified as Class 1 SUs (Arcadis 2020).

3.6 SPECIFY LIMITS ON DECISION ERRORS The sixth step in the DQO process examined the consequences of making an incorrect decision and establishes bounds of decision errors. Decision errors are controlled during the survey design, on-site field investigations, and during the data assessment. For this confirmatory survey effort, there were two orders of control.

The first order of control was to limit the uncertainty of the estimated CU mean ROC concentration. Conservative planning inputs for estimating the mean at the 95% confidence level within 87 pCi/g (20% of the DCGLU-tot) above/below the true mean served the basis for sample size determination.

The second order of control was to minimize the minimum detectable concentrations (MDCs) of field instrumentation and laboratory analytical equipment. Scan MDCs for field instrumentation were below the DCGLU-tot based on survey procedures described in Section 4. Table 3.2 provides nominal total uranium scan MDCs based on the calculation methodology described in UNC Naval Confirmatory Survey Report 8 5340-SR-01-0

NUREG-1507 (NRC 1998). Any anomalies above background identified while performing the surveys or subsequent data assessments were investigated thoroughly and discussed with NRC staff.

Table 3.2. Total Uranium Scan MDC for 2-inch by 2-inch NaI Detectora U-235 Assay Weighted Detector Scan MDC Response (cpm/- (pCi/g) uR/h) 3% 4,328 140 20% 5,027 160 50% 5,106 200 75% 5,129 230 93% 5,141 250 a Based on scan MDC calculation methodology outlined in NRC 1998. Assumes 0.25 m2 source size, d = 2.32, a detector background of 10,000 cpm, and a 1-second observation interval.

NaI = sodium iodide cpm = counts per minute uR = microrem h = hour 3.7 OPTIMIZE THE DESIGN FOR OBTAINING DATA The seventh step in the DQO process was used to review DQO outputs, develop data collection design alternatives, formulate mathematical expressions for each design, select the sample size to satisfy DQOs, decide on the most resource-effective design of agreed alternatives, and document requisite details. Specific survey procedures are presented in Section 4.

4. PROCEDURES The ORISE survey team performed visual inspections, measurements, and sampling activities requested by NRC staff during the period of October 6-8, 2020. Survey activities were conducted in accordance with the project-specific confirmatory survey plan, the Oak Ridge Associated Universities (ORAU) Radiological and Environmental Survey Procedures Manual, and the ORAU Environmental Services and Radiation Training Quality Program Manual (ORISE 2020, ORAU 2016, ORAU 2019). Appendices C and D provide additional information regarding survey instrumentation and related processes discussed within this section.

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4.1 REFERENCE SYSTEM ORISE referenced confirmatory measurement/sampling locations to global positioning system (GPS) coordinates using the NAD 1983 (CORS96) State Plane Connecticut FIPS 0600 (meters). Measurement and sampling locations were documented on detailed survey maps. Specific areas were also digitally photographed.

4.2 SURFACE SCANS For land areas, Ludlum model 44-10 2-inch by 2-inch thallium-doped sodium iodide (NaI[Tl]),

hereafter referred to as NaI, detectors were used to evaluate direct gamma radiation levels.

Accessible areas of the site were scanned with medium- to high-density coverage. All detectors were coupled to Ludlum Model 2221 ratemeter-scalers with audible indicators. Ratemeter-scalers also were coupled to hand-held GPS data-loggers to electronically record detector response concurrently with geospatial coordinates. Locations of elevated response that were audibly distinguishable from localized background levels, suggesting the presence of residual contamination, were marked for further investigation via volumetric sampling.

For piping, a Ludlum model 44-157 2-inch by 2-inch NaI Scintillation Detector Model 44-157, was used to evaluate direct gamma radiation levels on interior surfaces. The detector was coupled to a Ludlum Model 2221 ratemeter-scaler with audible indicators.

4.3 MEASUREMENT/SAMPLING LOCATIONS For land areas, soil samples were collected from both randomly- and judgmentally-selected locations. The data sets generated for CUs 1, 2, and 3 were for the purpose of estimating the mean.

Visual Sample Plan (VSP), version 7, was used to assess the sample size required for decision making and to randomly place locations throughout the CUs. The sample size determination is discussed in the following subsection. The total number of judgmental measurements was based upon findings during gamma surface scans or NRC direction.

For piping, 1-minute, static NaI gamma counts were recorded in 1-foot segments for the accessible length of the pipe. Soil/debris was collected if present.

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4.3.1 Ranked Set Sampling A ranked-set-sampling (RSS) process, following U.S. Environmental Protection Agency (EPA) guidance, was used to select a sample set for an unbiased estimate of the mean (EPA 2002) in CUs 1, 2, and 3. RSS provides a methodology to determine the necessary number of soil samples to estimate the mean concentration of a population. However, it does not require the assumption of a normal distribution. The process combines random sampling with the use of a field screening method capable of distinguishing the relative magnitude of a parameter of interest in a population in combination with professional judgment to select sampling locations. For this effort, 1-minute, static NaI gamma counts collected at each of the randomly-selected locations provided the measurable field screening method that correlated with the relative concentrations of the gamma-emitting ROCs. The professional-judgmental component was the ability to assess the magnitude of gamma radiation levels (count rates) between randomly-selected locations. The count rate data obtained from the group of random gamma measurement locations then was used to select specific locations for collecting the confirmatory soil samples.

The RSS systematic-planning process used a replication method on a larger random population from which the locations for the resulting samples were selected. Replication refers to the number of cycles (r) for performing a set size (m) of field measurement. The set size was maintained at three locations (m = 3) to minimize ranking errors. The number of assessment locations per cycle is dependent on the set size and is simply m2. Therefore, in a given cycle, samples were collected from each set based on the following ranking criteria:

• Set 1: The lowest gamma count value of three locations within Set 1 is sampled.

• Set 2: The middle gamma count value of three locations within Set 2 is sampled.

• Set 3: The highest gamma count value of three locations within Set 3 is sampled.

The number of repetitive cycles was dependent on the total number of soil samples (n) required and is a function of n and msimply defined as n = m x r. VSP was used to calculate the number of required samples. Inputs to this calculation were the desired confidence level of the estimated mean, allowable uncertainty of the estimated mean, and expected variability. Based on the planning inputs specified in Section 3.6, nine samples (i.e., n = 9) were collected. Therefore, with nine required soil UNC Naval Confirmatory Survey Report 11 5340-SR-01-0

samples, the number of repetitive cycles was 3 (r = n/m = 9/3 = 3). The total number of assessment locations per CU was defined as m2 x r (where r = 3 in this case), which was 32 x 3 = 27.

4.4 SOIL SAMPLING Soil samples were collected from both randomly- and judgmentally-selected locations as discussed in Section 4.3. Two locations were identified during surface scans with elevated direct gamma radiation levels distinguishable from background and samples were collected.

Prior to soil sampling, a 1-minute, static gamma radiation measurement was performed and then the surface soil sample was collected from a depth of 0 to 15 centimeters (cm) followed by a static gamma radiation measurement at the 15-cm depth. A subsurface sample was collected at one judgmentally-selected location following the collection of the surface sample because of a notable increase in the gamma count rate.

Soil samples were collected using clean hand trowels. All sampling equipment was rinsed in the field after the collection of each sample to prevent cross-contamination. Table 4.1 provides a summary of the soil samples collected.

Table 4.1. Summary of Volumetric Samples Collected Sample Collection Type Depth/Type No. Collected Surface-Soil 9 RSS Surface-Soil 9 Surface-Soil 9 Surface-Soil 2 Judgmental Subsurface-soil (15-30 cm) 1 Soil/Sediment in pipes 2 Total 32 4.5 MISCELLANEOUS SAMPLES Two samples, consisting of soil/sediment and vegetation debris, were collected from within a pipe connected to Catch Basin-22 (CB-22) (sample 5340S0028) and what the site called the East Pipe (sample 5340S0029). The pipe samples were collected with clean scooping tools attached to an extension pole.

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5. SAMPLE ANALYSIS AND DATA INTERPRETATION Samples and data collected on site were transferred to the ORISE facility for analysis and interpretation. Sample custody was transferred to the Radiological and Environmental Analytical Laboratory (REAL) in Oak Ridge, Tennessee. Sample analyses were performed in accordance with the ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2020a). Soil samples were homogenized and analyzed by gamma spectrometry for gamma-emitting radionuclides.

Analytical results were reported in units of pCi/g. The sites cleanup plan states that the total uranium concentration in each FSS sample will be calculated by inferring the U-234 concentration based on the U-235 assay (Arcadis 2019). Total uranium concentration was calculated in the same manner for the confirmatory soil samples. NRC staff did not direct ORISE to perform isotopic uranium analysis via alpha-spec, nor did ORISE recommend isotopic-specific analysisbased on review of the gamma spec data. Total uranium concentration is calculated by:

, = 238 + 235 1 + 234/235 Where:

CU,tot = total uranium sample concentration, CU-238 = U-238 sample concentration, CU-235 = U-235 sample concentration, and R234/235 = Activity ratio of U-234 to U-235 for a U-235 assay of 93%=27.

Random soil sample and gamma walkover results were graphed in quantile (Q) plots for assessment, and are discussed further in Section 6. The Q-plot is a graphical tool for assessing the distribution of a dataset. The Y-axis represents the ROC concentrations in units of pCi/g for sample data and cpm for scan data. The X-axis represents the data quantiles about the mean value. Values less than the mean are represented in the negative quantiles; the values greater than the mean are represented in the positive quantiles. A normal distribution that is not skewed by outliers (i.e., a background population) will appear as a straight line, with the slope of the line subject to the degree of variability among the data population. More than one distribution, such as background plus contamination or other outliers, will appear as a step function.

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6. FINDINGS AND RESULTS The results of the confirmatory survey are discussed in the following subsections.

6.1 SURFACE SCANS Figures A.3 through A.6 in Appendix A present the gamma walkover data for each CU. Overall, the gamma responses ranged from approximately 3,600 counts per minute (cpm) to 15,500 cpm.

Table 6.1 provides the summary statistics for the gamma walkover survey. Figure 6.1 presents Q-plots for gamma walkover survey data in each CU. The shape of the Q-plots in Figure 6.1 are consistent with multiple background conditionsnotably, CU2 and CU3rather than the presence of contamination.

Two areas had elevated gamma radiation levels slightly distinguishable from background in CU2; see Figure A.4 (red locations). Both locations were localized (less than 1 m2) and had slightly-elevated gamma radiation levels compared to surrounding gamma radiation levels. The locations were marked for judgmental sampling.

Table 6.1. Gamma Walkover Summary Statistics Statistic (cpm)

Area Min Max Median Mean SD CU1 4,982 10,500 7,590 7,605 662 CU2 4,260 15,546 6,773 6,844 1,314 CU3 4,148 12,060 8,444 8,210 1,446 CU3 (Slab) 3,987 7,535 5,039 5,111 514 CU4 3,654 9,946 6,423 6,529 964 UNC Naval Confirmatory Survey Report 14 5340-SR-01-0

Figure 6.1. Q-plots for Confirmatory Gamma Walkover Surveys ORISE staff collected measurements in all piping that was visibly identified during walk-downs with the exception of piping containing visible asbestos material present. As previously mentioned most piping had caved in preventing survey and, therefore, measurements were collected just inside the pipe opening. However, 1-minute static measurements were recorded at 0.3 m (1 foot) increments at numerous locations within 2 pipes. Table 6.2 presents the single measurement or scan ranges for all piping assessed.

UNC Naval Confirmatory Survey Report 15 5340-SR-01-0

Table 6.2. Summary of Piping Assessed, Scan Ranges Piping Scan Range (cpm)a Piping Scan Range (cpm)a CB-20 10,871 to NA C-38e 10,235 to NA CB-20b 16,344 to NA East pipe 13,200 to 16,200 Water pipe in concrete trench CB-22 15,300 to 19,200 between columns 6,329 to NA 14 and 15 Water pipe in CB-22/CB-23c 12,000 to 16,000 concrete trench in 4,300 to NA line with column 6 CB-26d 9,106 to NA C45 Manway 12,000 to 14,000 aLudlum Detector Model 44-157 used. If a range is not provided, the pipe was caved in and only a 1-min static gamma measurement was collected at the pipe opening.

bMeasurement was collected in a remaining pipe heading west from the CB-20 excavation.

cScan range for a pipe that connected CB-22 to CB-23. Only 9 feet of piping was accessible.

dCB-26 was removed; the measurement was collected in a remaining pipe heading east from the CB-26 excavation.

eColumn-38 storm water piping.

Raw detector responses, in units of cpm, were plotted to examine the NaI gamma response profile of the CB-22 and the East Pipe. These plots are presented in Figure 6.2. The profile for CB-22 indicates about a 1,600 cpm increase in the NaI detector response approximately 2 m inside the pipe.

The exact cause of the increase is not known, a sample of available material was collected from this pipe.

UNC Naval Confirmatory Survey Report 16 5340-SR-01-0

Figure 6.2. Piping NaI Gamma Response Depth Profile 6.2 RADIONUCLIDE CONCENTRATIONS IN SOIL AND MISCELLANEOUS SAMPLES Figures A.7 through A.9 in Appendix A provide a graphical representation of all RSS locations where 1-minute, static gamma measurements were collected along with the resulting detector response used for the field ranking. Figures A.10 through A.12 display the locations for the soil samples collected. Ranked set sampling locations and sample coordinates, the soil sample pre- and post-sample static gamma counts, and uranium concentrations are presented in Tables B.1, B.2, and B.3 in Appendix B. The total uranium concentrations for all random soil samples are presented in Table B.4. The sample coordinates, the soil sample pre- and post-sample static gamma counts, and uranium concentrations for judgmental samples are presented in Table B.5.

Table 6.3 provides the summary statistics for the uranium concentrations in the randomly-selected soil samples.

UNC Naval Confirmatory Survey Report 17 5340-SR-01-0

Table 6.3. Summary Statistics for Radionuclide Concentrations in Random Soil Samples Statistic (pCi/g)

ROC Min Max Median Mean SD CU1 (Bldg. 3H Footprint)

U-235 0.029 0.24 0.098 0.11 0.03 U-238 0.29 0.91 0.67 0.65 0.07 Total U 1.62 7.63 3.48 3.72 0.77 CU2 (Bldg. 6H Center Footprint)

U-235 0.00 0.148 0.07 0.06 0.05 U-238 0.12 1.03 0.62 0.66 0.31 Total U 0.4 4.49 2.88 2.39 1.52 CU3 (Bldg. 6H West Footprint)

U-235 -0.026 0.14 0.029 0.03 0.01 U-238 -0.02 1.28 0.36 0.56 0.17 Total U -0.14 4.28 0.79 1.48 0.24 The two locations identified in CU2 during gamma walkover surveys with slightly elevated radiation levels were sampled. At the first location, two samples were collected. Following the collection of the surface soil sample 5340S0030, the gamma radiation levels increased notably. A second sample 5340S0031 was collected of the 15 to 30 cm depth and the gamma radiation levels increased again.

NRC staff requested additional excavation at this location to further investigate the increasing radiation levels. Three excavator buckets of soil were removed and spread out in thin layers. ORISE performed gamma scans following the removal of each bucket. After the removal of the third bucket, the radiation levels decreased. No additional samples were collected at this location.

At the second location, judgmental sample 5340S0032 was collected in the side wall of an excavation and above a pipe adjacent to CB-22.

All random and judgmental samples collected had concentrations that were less than the NRC approved total uranium DCGLU-tot. The random soil sample data sets in CUs 1, 2, and 3 provide NRC with an unbiased estimate of the residual mean ROC concentration. One error occurred during the field ranking process, precluding assessment of data from CU2 using traditional RSS methods (see Table B.2). However, the RSS approach is as efficient as simple random sampling, regardless of the accuracy in the field ranking (Presnell 1999). As a result, there was a slight increase in the uncertainty of the estimated mean for CU2, relative to what was planned, although the UNC Naval Confirmatory Survey Report 18 5340-SR-01-0

uncertainty is not greater than that resulting from the collection of nine random samples. Because there were no uranium concentrations identified near or greater than the DCGLU-tot in the sample set for CU2, the increased uncertainty does not limit confirmatory survey decisions.

Figure 6.3 provides a Q-plot of uranium concentrations for the ORISE confirmatory data sets.

Review of Figure 6.3 indicates that shape of the Q-plot indicates an approximately normal distribution. Data near the analytical MDC are represented by the relatively flat portion of the curve present at the lower quantiles. The shape of the Q-plots are consistent with background conditions.

Figure 6.3. Q-plots for ORISE Confirmatory Survey Soil Sample Uranium Concentrations

7.

SUMMARY

AND CONCLUSIONS During the period of October 6-8, 2020, ORISE performed independent confirmatory survey activities of surface soils and remaining piping associated with the UNC Naval Products site. The confirmatory survey activities consisted of gamma walkover surface scans of the entire site, gamma direct measurements, and surface and subsurface (one location) soil sampling.

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Gamma scans identified two areas of elevated radiation distinguishable from background. These two locations had slightly-elevated gamma radiation levels compared to surrounding gamma radiation levels. Thirty-two total soil samples were collected. Twenty-seven sample locations were randomly selected, with 9 surface samples collected within each of the CUs 1, 2, and 3. The two identified areas with slightly elevated gamma radiation levels in CU2 were judgmentally selected for sampling:

three samples were collected from the two locations. Additionally, two judgmental samples were collected from piping: one from CB-22 piping and one from the East Pipe. All random and judgmental samples collected had concentrations that were less than the NRC approved total uranium DCGLU-tot.

Based on the results of the collected confirmatory survey data, ORISE did not identify instances of residual activity that exceeded the DCGL for total uranium. Additionally, the confirmatory survey data assessment confirmed that project DQOs were met.

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8. REFERENCES AAA 2008.Derived Concentration Guideline Levels for Decommissioning the former UNC Manufacturing Facility, Revision 1. Report No. 2002020/G-3972. AAA Environmental, Inc. Syracuse, New York and Integrated Environmental Management, Inc. Findlay, Ohio. June 16.

Arcadis 2019. Final Status Survey Plan, Revision 2, Former United Nuclear Corporation Naval Products Facility New Haven, Connecticut. Arcadis Design & Consultancy. Netherlands. July 23.

Arcadis 2020. Cleanup Plan Former United Nuclear Corporation Naval Products Facility New Haven, Connecticut. Arcadis Design & Consultancy. Netherlands. May 7.

Cabrera 2018. Final Status Survey Report, Site Decommissioning Former UNC Facility New Haven, Connecticut. NRC ADAMS Accession No. ML19163A377. Cabrera Services, Inc. East Hartford, Connecticut. November.

EPA 2002. Guidance on Choosing a Sampling Design for Environmental Data Collection. EPA QA/G-5S.

U.S. Environmental Protection Agency. Washington, D.C. December.

EPA 2006. Guidance on Systematic Planning Using the Data Quality Objectives Process. EPA QA/G-4.

U.S. Environmental Protection Agency. Washington, D.C. February.

NRC 1973. Guidelines for Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses for Byproducts, Source, or Special Nuclear Material. U.S. Nuclear Regulatory Commission. Washington, D.C. May 3.

NRC 1974. Regulatory Guide 1.86. Termination of Operating Licenses for Nuclear Reactors (STC-16-073).

U. S. Nuclear Regulatory Commission. Washington, D.C. June.

NRC 1981. Disposal or Onsite Storage of Thorium or Uranium Wastes from Past Operations. Branch Technical Position. 46 CFR 52061. U.S. Nuclear Regulatory Commission. Washington, D.C.

October 23.

NRC 1996. Inspection Report No. 070-00371/96-01. U.S. Nuclear Regulatory Commission.

Washington, D.C. July 26.

NRC 1998. Minimum Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions. NUREG-1507. U.S. Nuclear Regulatory Commission. Washington, D.C. June.

ORAU 2016. ORAU Radiological and Environmental Survey Procedures Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. November 10.

ORAU 2019. ORAU Environmental Services and Radiation Training Quality Program Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. April 30.

ORAU 2020a. ORAU Radiological and Environmental Analytical Laboratory Procedures Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. June30.

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ORAU 2020b. ORAU Radiation Protection Manual, ESH-MAN-03. Oak Ridge Associated Universities. Oak Ridge, Tennessee. November.

ORAU 2020c. ORAU Health and Safety Manual, ESH-MAN-05. Oak Ridge Associated Universities.

Oak Ridge, Tennessee. October.

ORISE 1997. Radiological Scoping Survey of Buildings 3H and 6H at the Former UNC H-Tract Facility, New Haven, Connecticut. Oak Ridge, Tennessee. January.

ORISE 2020. Project-Specific Plan for the Confirmatory Survey Activities at the Former UNC Products Facility, New Haven, Connecticut. DCN 5340-PL-01-0. Oak Ridge, Tennessee. March.

Presnell 1999. U-Statistics and imperfect ranking in ranked set sampling. Journal of Nonparametric Statistics. Vol. 10, Issue 2. 1999.

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APPENDIX A:

FIGURES UNC Naval Confirmatory Survey Report 5340-SR-01-0

Figure A.1. UNC Naval Site Layout UNC Naval Confirmatory Survey Report A-1 5340-SR-01-0

Figure A.2. Confirmatory Unit (CU) Boundaries UNC Naval Confirmatory Survey Report A-2 5340-SR-01-0

Figure A.3. Gamma Walkover Data for CU1, Building 3H Footprint UNC Naval Confirmatory Survey Report A-3 5340-SR-01-0

Figure A.4. Gamma Walkover Data for CU2, Building 6H Center Footprint UNC Naval Confirmatory Survey Report A-4 5340-SR-01-0

Figure A.5. Gamma Walkover Data for CU3, Building 6H West Footprint UNC Naval Confirmatory Survey Report A-5 5340-SR-01-0

Figure A.6. Gamma Walkover Data for CU4, Balance of the Site UNC Naval Confirmatory Survey Report A-6 5340-SR-01-0

Figure A.7. RSS Locations for CU1, Building 3H Footprint UNC Naval Confirmatory Survey Report A-7 5340-SR-01-0

Figure A.8. RSS Locations for CU2, Building 6H Center Footprint UNC Naval Confirmatory Survey Report A-8 5340-SR-01-0

Figure A.9. RSS Locations for CU3, Building 6H West Footprint UNC Naval Confirmatory Survey Report A-9 5340-SR-01-0

Figure A.10. Soil Sample Locations for CU1, Building 3H Footprint UNC Naval Confirmatory Survey Report A-10 5340-SR-01-0

Figure A.11. Soil Sample Locations for CU2, Building 6H Center Footprint UNC Naval Confirmatory Survey Report A-11 5340-SR-01-0

Figure A.12. Soil Sample Locations for CU3, Building 6H West Footprint UNC Naval Confirmatory Survey Report A-12 5340-SR-01-0

APPENDIX B:

TABLES UNC Naval Confirmatory Survey Report 5340-SR-01-0

Table B.1. CU1 (Building 3H Footprint) RSS Field Ranking and Sample Data Field Ranking, Post- Total RSS Easting Northing Sample U-235 U-238 Pre- Rank sample Uranium ID (m) (m) ID (pCi/g) (pCi/g) sample (cpm) (pCi/g)

(cpm) 1-1-1 289600 206911 7,115 L 5340S0004 7,747 0.098 0.74 3.5 1-1-2 289579 206924 7,602 L 1-1-3 289620 206902 10,000 L 1-2-1 289569 206915 7,895 M 1-2-2 289630 206908 7,525 M 5340S0009 8,285 0.19 0.77 6.1 1-2-3 289556 206921 7,145 M 1-3-1 289597 206899 7,130 H 1-3-2 289577 206912 6,848 H 1-3-3 289607 206917 7,350 H 5340S0006 8,626 0.24 0.91 7.63 2-1-1 289628 206891 8,782 L 2-1-2 289602 206917 6,880 L 5340S0005 7,413 0.029 0.81 1.62 2-1-3 289623 206908 8,446 L 2-2-1 289572 206922 7,631 M 2-2-2 289612 206900 8,285 M 2-2-3 289592 206913 8,028 M 5340S0003 9,393 0.063 0.53 2.3 2-3-1 289593 206905 7,086 H 2-3-2 289572 206919 8,340 H 5340S0002 8,702 0.04 0.58 1.7 2-3-3 289613 206897 8,161 H 3-1-1 289562 206910 7,812 L 3-1-2 289557 206928 7,269 L 5340S0001 8,973 0.119 0.67 4.00 3-1-3 289578 206907 7,715 L 3-2-1 289608 206911 8,465 M 3-2-2 289629 206902 7,095 M 5340S0008 7,735 0.06 0.53 2.2 3-2-3 289555 206916 6,952 M 3-3-1 289616 206904 9,012 H 5340S0007 9,401 0.15 0.29 4.5 3-3-2 289565 206918 7,172 H 3-3-3 289585 206909 7,298 H UNC Naval Confirmatory Survey Report B-1 5340-SR-01-0

Table B.2. CU2 (Building 6H Center Footprint) RSS Field Ranking and Sample Data Field Ranking, Post- Total RSS Easting Northing Sample U-235 U-238 Pre- Rank sample Uranium ID (m) (m) ID (pCi/g) (pCi/g) sample (cpm) (pCi/g)

(cpm) 1-1-1 289531 206937 7,394 L 1-1-2 289553 206929 7,265 L 5340S0010 7,684 0 1.03 1.03 1-1-3 289471 206941 8,982 L 1-2-1 289516 206920 5,701 M 1-2-2 289494 206933 8,194 M 1-2-3 289528 206926 7,490 M 5340S0012 8,385 0.124 0.93 4.40 1-3-1 289550 206918 7,041 H 1-3-2 289511 206924 6,242 H 1-3-3 289511 206928 8,240 H 5340S0014 9,435 0.026 0.51 1.24 2-1-1 289534 206920 5,721 L 2-1-2 289477 206934 5,442 L 5340S0018 4,995 0.093 0.55 3.2 2-1-3 289545 206925 6,933 L 2-2-1 289471 206937 9,419 M 2-2-2 289494 206929 7,672 M 5340S0016 8,714 0.014 0.62 1.01 2-2-3a 289551 206914 7,695 M 2-3-1 289537 206930 7,126 H 2-3-2 289525 206922 7,437 H 2-3-3 289503 206935 7,523 H 5340S0015 8,222 0.01 0.12 0.4 3-1-1 289520 206924 7,479 L 3-1-2 289497 206936 9,216 L 3-1-3 289542 206916 5,144 L 5340S0011 5,304 0.148 0.35 4.49 3-2-1 289486 206928 9,075 M 3-2-2 289524 206930 8,694 M 5340S0013 10,988 0.07 0.92 2.9 3-2-3 289547 206921 7,025 M 3-3-1 289473 206934 6,669 H 3-3-2 289541 206927 6,551 H 3-3-3 289484 206939 9,206 H 5340S0017 10,472 0.07 0.95 2.91 aField ranking error. RSS ID 2-2-3 should have been sampled instead of RSS ID 2-2-2. See section 6.2 for details.

UNC Naval Confirmatory Survey Report B-2 5340-SR-01-0

Table B.3. CU3 (Building 6H West Footprint) RSS Field Ranking Data Field Ranking, Post- Total RSS Easting Northing Sample U-235 U-238 Pre- Rank sample Uranium ID (m) (m) ID (pCi/g) (pCi/g) sample (cpm) (pCi/g)

(cpm) 1-1-1 289411 206957 7,979 L 5340S0027 9,497 -0.017 0.34 -0.14 1-1-2 289461 206950 8,733 L 1-1-3 289419 206963 8,611 L 1-2-1 289453 206941 8,633 M 5340S0021 10,255 0.03 0.71 1.6 1-2-2 289436 206954 10,082 M 1-2-3 289439 206959 8,491 M 1-3-1 289414 206948 5,257 H 1-3-2 289464 206952 8,419 H 5340S0019 10,131 0.14 0.36 4.3 1-3-3 289413 206965 7,063 H 2-1-1 289443 206943 7,197 L 5340S0022 9,028 0.007 0.32 0.5 2-1-2 289426 206956 8,857 L 2-1-3 289452 206949 9,585 L 2-2-1 289410 206954 9,045 M 2-2-2 289424 206945 5,183 M 2-2-3 289414 206967 7,276 M 5340S0026 8,803 0.013 0.32 0.68 2-3-1 289433 206951 8,703 H 2-3-2 289445 206955 8,762 H 5340S0023 11,477 0.09 0.91 3.4 2-3-3 289462 206946 8,572 H 3-1-1 289420 206959 10,631 L 3-1-2 289420 206952 9,397 L 3-1-3 289445 206957 8,092 L 5340S0024 9,990 -0.026 0.82 0.09 3-2-1 289462 206936 5,993 M 5340S0020 6,789 0.029 -0.02 0.79 3-2-2 289407 206950 5,085 M 3-2-3 289458 206954 9,968 M 3-3-1 289416 206967 7,049 H 3-3-2 289449 206945 8,172 H 3-3-3 289433 206958 9,591 H 5340S0025 12,730 0.03 1.28 2.1 UNC Naval Confirmatory Survey Report B-3 5340-SR-01-0

Table B.4. Radionuclide Concentrations in Random Soil Samples ROC (pCi/g)

Sample ID Area U-235 U-238 Total Uranium Conc. TPUa Conc. TPU Conc. TPU 5340S0001 CU1 0.119 +/- 0.098 0.67 +/- 0.37 4.0 +/- 2.7 5340S0002 CU1 0.04 +/- 0.12 0.58 +/- 0.38 1.7 +/- 3.3 5340S0003 CU1 0.063 +/- 0.096 0.53 +/- 0.74 2.3 +/- 2.7 5340S0004 CU1 0.098 +/- 0.081 0.74 +/- 0.35 3.5 +/- 2.2 5340S0005 CU1 0.029 +/- 0.094 0.81 +/- 0.32 1.6 +/- 2.6 5340S0006 CU1 0.240 +/- 0.095 0.91 +/- 0.51 7.6 +/- 2.6 5340S0007 CU1 0.15 +/- 0.12 0.29 +/- 0.79 4.5 +/- 3.3 5340S0008 CU1 0.060 +/- 0.075 0.53 +/- 0.32 2.2 +/- 2.1 5340S0009 CU1 0.19 +/- 0.11 0.77 +/- 0.38 6.1 +/- 3.0 5340S0010 CU2 0.00 +/- 0.13 1.03 +/- 0.48 1.0 +/- 3.5 5340S0011 CU2 0.148 +/- 0.077 0.35 +/- 0.51 4.5 +/- 2.1 5340S0012 CU2 0.124 +/- 0.090 0.93 +/- 0.41 4.4 +/- 2.5 5340S0013 CU2 0.07 +/- 0.10 0.92 +/- 0.42 2.9 +/- 2.7 5340S0014 CU2 0.026 +/- 0.081 0.51 +/- 0.33 1.2 +/- 2.2 5340S0015 CU2 0.01 +/- 0.10 0.12 +/- 0.60 0.4 +/- 2.8 5340S0016 CU2 0.014 +/- 0.078 0.62 +/- 0.33 1.0 +/- 2.1 5340S0017 CU2 0.07 +/- 0.11 0.95 +/- 0.46 2.9 +/- 3.0 5340S0018 CU2 0.093 +/- 0.080 0.55 +/- 0.43 3.2 +/- 2.2 5340S0019 CU3 0.14 +/- 0.11 0.36 +/- 0.83 4.3 +/- 3.1 5340S0020 CU3 0.029 +/- 0.064 -0.02 +/- 0.36 0.8 +/- 1.8 5340S0021 CU3 0.03 +/- 0.11 0.71 +/- 0.29 1.6 +/- 3.0 5340S0022 CU3 0.007 +/- 0.084 0.32 +/- 0.58 0.5 +/- 2.3 5340S0023 CU3 0.09 +/- 0.11 0.91 +/- 0.51 3.4 +/- 3.0 5340S0024 CU3 -0.026 +/- 0.084 0.82 +/- 0.43 0.1 +/- 2.3 5340S0025 CU3 0.03 +/- 0.11 1.28 +/- 0.83 2.1 +/- 3.1 5340S0026 CU3 0.013 +/- 0.064 0.32 +/- 0.31 0.7 +/- 1.8 5340S0027 CU3 -0.017 +/- 0.063 0.34 +/- 0.35 -0.1 +/- 1.7 aUncertainties represent total propagated uncertainties, reported at the 95 % confidence level ROC = radionuclide of concern UNC Naval Confirmatory Survey Report B-4 5340-SR-01-0

Table B.5. Radionuclide Concentrations in Judgmental Soil Samples ROC (pCi/g)

Pre- Post-Sample ID Area sample sample U-235 U-238 Total Uranium (cpm) (cpm)

Conc. TPUa Conc. TPU Conc. TPU 5340S0028b CU4 -- -- 0.24 +/- 0.58 -2.1 +/- 2.7 4.6 +/- 15.9 5340S0029c CU4 -- -- 3.31 +/- 0.33 0.97 +/- 0.46 93.7 +/- 8.9 5340S0030d CU2 13,785 22,093 0.27 +/- 0.12 2.0 +/- 1.0 9.7 +/- 3.3 5340S0031e CU2 22,093 31,258 0.15 +/- 0.15 3.43 +/- 0.86 7.6 +/- 4.1 5340S0032f CU2 11,859 13,755 0.16 +/- 0.13 0.40 +/- 0.42 4.8 +/- 3.5 aUncertainties represent total propagated uncertainties, reported at the 95 % confidence level bSample 5340S0028 consisted of vegetation debris collected from pipe connected to Catch Basin-22 cSample 5340S0029 consisted of sediment/debris collected from the 'East Pipe' dSample coordinates 289523.3 E, 206925.4 N in meters eSample 5340S0031 was collected at the sample location as sample 5340S0030 at the 15-30 cm depth fSample coordinates 289505.8 E, 206922.5 N in meters.

ROC = radionuclide of concern UNC Naval Confirmatory Survey Report B-5 5340-SR-01-0

APPENDIX C: MAJOR INSTRUMENTATION UNC Naval Confirmatory Survey Report 5340-SR-01-0

C.1. SCANNING AND MEASUREMENT INSTRUMENT/

DETECTOR COMBINATIONS The display of a specific product is not to be construed as an endorsement of the product or its manufacturer by the author or his employer.

C.1.1 GAMMA Ludlum NaI[Tl] Scintillation Detector Model 44-10, Crystal: 5.1 cm x 5.1 cm Coupled to: Ludlum Ratemeter-scaler Model 2221 (Ludlum Measurements, Inc., Sweetwater, Texas)

Coupled to: Trimble Geo 7X (Trimble Navigation Limited, Sunnyvale, CA)

Ludlum NaI Scintillation Detector Model 44-157, Crystal: 5.1 cm x 5.1 cm coupled to: Ludlum Ratemeter-scaler Model 2221 (Ludlum Measurements, Inc., Sweetwater, Texas)

C.2. LABORATORY ANALYTICAL INSTRUMENTATION High-Purity, Extended Range Intrinsic Detector CANBERRA/Tennelec Model No: ERVDS30-25195 Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)

Used in conjunction with:

Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)

High-Purity, Intrinsic Detector EG&G ORTEC Model No. GMX-45-76-CW-S Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)

Used in conjunction with:

Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)

UNC Naval Confirmatory Survey Report C-1 5340-SR-01-0

High-Purity, Intrinsic Detector EG&G ORTEC Model No. GMX-30P4 Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)

Used in conjunction with:

Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)

High-Purity, Intrinsic Detector EG&G ORTEC Model No. CDG-SV-76/GEM-MX5970-S Canberra Lynx Multichannel Analyzer Canberra Gamma-Apex Software (Canberra, Meriden, Connecticut)

Used in conjunction with:

Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Dell Workstation (Canberra, Meriden, Connecticut)

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APPENDIX D: SURVEY AND ANALYTICAL PROCEDURES UNC Naval Confirmatory Survey Report 5340-SR-01-0

D.1. PROJECT HEALTH AND SAFETY The Oak Ridge Institute of Science and Education (ORISE) performed all survey activities in accordance with the Oak Ridge Associated Universities (ORAU) Radiation Protection Manual, the ORAU Radiological and Environmental Survey Procedures Manual, and the ORAU Health and Safety Manual (ORAU 2020b, ORAU 2016a, and ORAU 2020c). Prior to on-site activities, a Work-Specific Hazard Checklist was completed for the project and discussed with field personnel. The planned activities were thoroughly discussed with site personnel prior to implementation to identify hazards present.

Additionally, prior to performing work, a pre-job briefing and walk down of the survey areas were completed with field personnel to identify hazards present and discuss safety concerns. Should ORISE have identified a hazard not covered in ORAU 2016a or the projects Work-Specific Hazard Checklist for the planned survey and sampling procedures, work would not have been initiated or continued until the hazard was addressed by an appropriate job hazard analysis and hazard controls.

D.2. CALIBRATION AND QUALITY ASSURANCE Calibration of all field instrumentation was based on standards/sources traceable to National Institute of Standards and Technology (NIST).

Field survey activities were conducted in accordance with procedures from the following documents:

• ORAU Radiological and Environmental Survey Procedures Manual (ORAU 2016a)

• ORAU Environmental Services and Radiation Training Quality Program Manual (ORAU 2019)

• ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2020a)

The procedures contained in these manuals were developed to meet the requirements of U.S. Department of Energy (DOE) Order 414.1D and NRCs Quality Assurance Manual for the Office of Nuclear Material Safety and Safeguards, and contain measures to assess processes during their performance.

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Quality control procedures include

• Daily instrument background and check-source measurements to confirm that equipment operation is within acceptable statistical fluctuations.

• Participation in Mixed-Analyte Performance Evaluation Program and Intercomparison Testing Program laboratory quality assurance programs.

• Training and certification of all individuals performing procedures.

• Periodic internal and external audits.

D.3. SURVEY PROCEDURES D.3.1 SURFACE SCANS Scans for elevated gamma radiation were performed by passing NaI detectors slowly over the surface. The distance between the detector and surface was maintained at a minimum. The thallium-doped sodium iodide (NaI[Tl]) scintillation detectors were used solely as a qualitative means to identify elevated radiation levels in excess of background in surface soil. Identification of elevated radiation levels that could exceed the localized background were determined based on an increase in the audible signal from the indicating instrument or were identified after post-processing the scan data while the team was still at the site. A NaI pipe detector was used to evaluate direct gamma radiation levels on the interior of piping remaining at the site. All detectors were coupled to Ludlum Model 2221 ratemeter-scalers with audible indicators.

D.3.2 SOIL SAMPLING Surface soil samples (approximately 0.5 kilogram each) were collected by ORISE personnel using a clean garden trowel to transfer soil into a new sample container. Soil or other debris was collected from piping if present or accessible to sample. All containers were labeled and security sealed in accordance with ORISE procedures and shipped under chain-of-custody to the ORISE laboratory for analysis.

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D.4. RADIOLOGICAL ANALYSIS D.4.1 GAMMA SPECTROSCOPY Samples were analyzed as received or homogenized, as necessary, and a dry portion sealed in a size-appropriate Marinelli beaker or container. The quantity placed in the beaker was chosen to reproduce the calibrated counting geometry. Net material weights were determined, and the samples were counted using intrinsic, high-purity, germanium detectors coupled to a pulse-height analyzer system. Background and Compton stripping, peak search, peak identification, and concentration calculations were performed using computer capabilities inherent in the analyzer system. All total absorption peaks (TAPs) associated with the radionuclides of concern (ROCs) were reviewed for consistency of activity. Spectra also were reviewed for other identifiable TAPs. TAPs used for determining the activities of the radionuclides and the typical associated minimum detectable concentrations (MDCs) for a 1-hour count time are presented in Table D.1.

Table D.1. Typical MDCs and TAPs for ROCs Radionuclidea TAP (MeV)b MDC (pCi/g)c U-235 0.186 0.05 U-238 0.063 0.75 aSpectra also were reviewed for other identifiable TAPs.

bMeV = mega electron volt cpicocurie per gram D.4.2 DETECTION LIMITS Detection limits, referred to as MDCs, were based on a 95% confidence level. Because of variations in background levels, measurement efficiencies, and contributions from other radionuclides in samples, the detection limits differed from sample to sample and instrument to instrument.

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