ML20127H834

Independent Confirmatory Survey Summary and Results of the Remaining Land Areas at the Zion Nuclear Power Station, Zion, Illinois

ML20127H834
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	04/24/2020
From:	Altic N Oak Ridge
To:	John Hickman Office of Nuclear Material Safety and Safeguards
J HICKMAN
References
DCN 5271-SR-08-0, DE-SC0014664
Download: ML20127H834 (81)

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April 24, 2020 Mr. John Hickman U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards Division of Decommissioning, Uranium Recovery, and Waste Programs Reactor Decommissioning Branch, Mail Stop: T8F5 11545 Rockville Pike Rockville, MD 20852

SUBJECT:

CONTRACT NO. DE-SC0014664 INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS OF THE REMAINING LAND AREAS AT THE ZION NUCLEAR POWER STATION, ZION, ILLINOIS; DOCKET NOs. 50-295 and 50-304; RFTA No.18-004 DCN 5271-SR-08-0

Dear Mr. Hickman:

The Oak Ridge Institute for Science and Education (ORISE) is pleased to provide the enclosed final report detailing the confirmatory survey activities for the remaining land areas at the Zion Nuclear Power Station in Zion, Illinois.

Please feel free to 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:tb electronic distribution: K. Conway, NRC B. Lin, NRC R. Edwards, NRC E. Bailey, ORISE D. Hagemeyer, ORISE File/5271

INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE REMAINING LAND AREAS AT THE ZION NUCLEAR POWER STATION ZION, ILLINOIS K. M. Engel ORISE FINAL REPORT Prepared for the U.S. Nuclear Regulatory Commission APRIL 2020 Further dissemination authorized to NRC only; other requests shall be approved by the originating facility or higher NRC programmatic authority.

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 REMAINING LAND AREAS AT THE ZION NUCLEAR POWER STATION ZION, ILLINOIS FINAL REPORT Prepared by K. M. Engel ORISE APRIL 2020 Prepared for the U.S. Nuclear Regulatory Commission 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 (ORAU) under DOE contract number DE-SC0014664.

ZNPS Land Areas Confirmatory Survey Report 5271-SR-08-0

INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE REMAINING LAND AREAS AT THE ZION NUCLEAR POWER STATION ZION, ILLINOIS Prepared by: Date: 4/24/2020 K. M. Engel, Health Physicist ORISE Reviewed by: Date: 4/24/2020 N. A. Altic, CHP, Health Physicist/Project Manager ORISE Reviewed by: Date: 4/24/2020 P. H. Benton, Quality Manager ORISE Reviewed by: Date: 4/24/2020 W. F. Smith, Senior Chemist ORISE Reviewed and approved for release by: Date: 4/24/2020 E. N. Bailey, Survey and Technical Projects Group Manager ORISE FINAL REPORT April 2020 ZNPS Land Areas Confirmatory Survey Report i 5271-SR-08-0

CONTENTS FIGURES .......................................................................................................................................................... iv TABLES ............................................................................................................................................................. iv ACRONYMS ..................................................................................................................................................... v EXECUTIVE

SUMMARY

............................................................................................................................ vii

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 Release Guidelines.............................................................. 6 3.4 Define the Study Boundaries ........................................................................................................... 7 3.5 Develop a Decision Rule.................................................................................................................. 8 3.5.1 PSQ1: FSS and Confirmatory Data Agreement ................................................................... 9 3.5.2 PSQ2: SU Classification .........................................................................................................11 3.6 Specify Limits on Decision Errors ...............................................................................................11 3.6.1 Hypothesis Testing .................................................................................................................11 3.6.2 Field and Analytical MDCs ...................................................................................................12 3.7 Optimize the Design for Obtaining Data....................................................................................13

4. PROCEDURES ..........................................................................................................................................13 4.1 Reference System ............................................................................................................................13 4.2 Surface Scans....................................................................................................................................13 4.3 Measurement/Sampling Locations...............................................................................................14 4.3.1 Simple Random Sampling (CU-2) ........................................................................................14 4.3.2 Ranked Set Sampling (CU-1 and CU-3) ..............................................................................14 4.4 Soil Sampling....................................................................................................................................15 4.5 Sediment Sampling ..........................................................................................................................16

5. SAMPLE ANALYSIS AND DATA INTERPRETATION ...............................................................16

6. FINDINGS AND RESULTS ...................................................................................................................17 6.1 Surface Scans....................................................................................................................................17 6.2 Radionuclide Concentrations in Soil Samples.............................................................................18 6.3 Radionuclide Concentrations in Sediment Samples ...................................................................22

7.

SUMMARY

AND CONCLUSIONS ......................................................................................................22 ZNPS Land Areas Confirmatory Survey Report ii 5271-SR-08-0

8. REFERENCES ...........................................................................................................................................24 APPENDIX A: FIGURES APPENDIX B: DATA TABLES APPENDIX C: MAJOR INSTRUMENTATION APPENDIX D: SURVEY AND ANALYTICAL PROCEDURES ZNPS Land Areas Confirmatory Survey Report iii 5271-SR-08-0

FIGURES Figure 2.1. ZNPS Overview (adapted from ZS 2018) ................................................................................. 3 Figure 2.2. Overview of ZNPS Survey Units (Adapted from NRC 2019)................................................ 3 Figure 3.1. Confirmatory Units 1, 2, and 3 .................................................................................................... 9 Figure 6.1. Q-Q Plot for ORISE Confirmatory Survey and Zion FSS Soil Sample Results from CU-2 (SU 12203A) .....................................................................................................................................................20 Figure 6.2. Strip Chart for Confirmatory Survey Judgmental Soil Samples ............................................21 Figure 6.3. Strip Chart for Confirmatory Survey Sediment Samples .......................................................22 TABLES Table 3.1. ZNPS Confirmatory Survey Decision Process ........................................................................... 5 Table 3.2. ZNPS Soil DCGLs and Corresponding MDCs (pCi/g) ........................................................... 7 Table 3.3. ZNPS Investigation Levels ..........................................................................................................11 Table 4.1. Summary of Volumetric Samples Collected ..............................................................................16 Table 6.1. Summary of Elevated Gamma Radiation Levels Identified During Scans ...........................18 Table 6.2. Summary of ROC Concentrations in Random Confirmatory Soil Samples.........................19 ZNPS Land Areas Confirmatory Survey Report iv 5271-SR-08-0

ACRONYMS AA alternative action CB catch basin CFR Code of Federal Regulations cm centimeter(s)

Co-60 cobalt-60 cpm counts per minute Cs-134 cesium-134 Cs-137 cesium-137 CU confirmatory unit DCGL derived concentration guideline level DCGLBC base case DCGL DCGLOp operational DCGL DQO data quality objective DS decision statement Exelon Exelon Generating Company FSS final status survey GPS global positioning system H-3 tritium H0 null hypothesis HA alternative hypothesis HTD hard-to-detect ISFSI independent spent fuel storage installation LTP license termination plan m2 square meter(s)

MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MeV mega electron volt MDC minimum detectable concentration MDCSCAN scan MDC mrem/yr millirem per year NaI[Tl] thallium-doped sodium iodide Ni-63 nickel-63 NIST National Institute of Standards and Technology 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 ROC radionuclide of concern RSS ranked set sampling SOF sum-of-fractions Sr-90 strontium-90 SU survey unit TAP total absorption peak ZNPS Land Areas Confirmatory Survey Report v 5271-SR-08-0

TEDE total effective dose equivalent TPU total propagated uncertainty VSP Visual Sample Plan ZNPS Zion Nuclear Power Station ZS ZionSolutions, LLC ZNPS Land Areas Confirmatory Survey Report vi 5271-SR-08-0

INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE REMAINING LAND AREAS AT THE ZION NUCLEAR POWER STATION ZION, ILLINOIS EXECUTIVE

SUMMARY

U.S. Nuclear Regulatory Commission (NRC) staff requested that the Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities of the remaining land areas at the Zion Nuclear Power Station (ZNPS) in Zion, Illinois.

ORISE performed independent assessment activities during the periods of December 2-5, 2019, and January 6-9, 2020. Confirmatory survey activities included gamma walkover surface scans, gamma direct measurements, and soil sampling. The areas investigated included all or a portion of survey areas 00150, 10201, 10202, 10203, 10206, 10207, 10208, 10209, 10211, 10213, 10214, 10219, 10220, 10221, 12102, 12103, 12112, 12113, 12201, 12203, 12204, and 12205. Seven locations were identified during surface soil scans as distinguishable from background and were marked for investigation. A total of 37 soil samples were collected: 30 random samples, three judgmental samples, and four rainwater catch basin (CB) drain sediment samples. Six of the random samples were subsurface soils; the remainder of the random samples were surface samples.

Of the seven identified areas with elevated gamma radiation levels, three were judgmentally selected for sampling. One of the judgmentally-sampled areas contained a piece of concrete-like debris, which was left with site personnel, while the soil from around the concrete was collected as a confirmatory oil sample. Three of the areas identified with elevated gamma radiation were investigated by the site, as directed by NRC staff. One of these areas had a discrete particle. A gamma walkover scan was performed after the discrete particle was sampled, and showed gamma radiation levels to be similar to the surrounding area. ORISE does not have the results of the investigation performed of the other two areas. The seventh area had widespread, elevated gamma radiation levels that increased closer to the independent spent fuel storage installation (ISFSI), which was expected as it contains the sites spent fuel.

The collected confirmatory survey data did not present any anomalous issues that would preclude the final status survey (FSS) data from demonstrating compliance with the release criterionwith ZNPS Land Areas Confirmatory Survey Report vii 5271-SR-08-0

the exception of the two judgmental locations identified (in SU 10220I and 12112) but not investigated by ORISE. NRC staff directed the site to investigate these areas; therefore, it is recommended that NRC staff evaluate the results of these investigations. Furthermore, the confirmatory survey data supports the SU classification. Laboratory analytical results for the sediment samples collected form the CBs in SU 00150 are presented for NRC staffs evaluation.

ZNPS Land Areas Confirmatory Survey Report viii 5271-SR-08-0

INDEPENDENT CONFIRMATORY SURVEY

SUMMARY

AND RESULTS FOR THE REMAINING LAND AREAS AT THE ZION NUCLEAR POWER STATION ZION, ILLINOIS

1. INTRODUCTION The Zion Nuclear Power Station (ZNPS) consisted of two reactors, Unit 1 and Unit 2 that operated commercially from 1973 to 1997 and 1974 to 1996, respectively. Cessation of nuclear operations was certified in 1998 after both reactor units were defueled and the fuel assemblies had been placed in a spent-fuel pool. Both units then were placed in safe storage pending the commencement of site decommissioning and dismantlement. In 2010, the U.S. Nuclear Regulatory Commission (NRC) operating license was transferred from Exelon Generating Company (Exelon) to ZionSolutions, LLC (ZS) to allow the physical decommissioning process, which is expected to be completed within 10 years. The end-state and primary decommissioning objective at ZNPS is the transfer of all spent nuclear fuel to the independent spent fuel storage installation (ISFSI) and to reduce residual radioactivity within structures and soils to levels below the criteria specified in 10 Code of Federal Regulations (CFR) 20.1402, permitting release of the site for unrestricted use. Upon successful completion of the decommissioning activities, control and responsibility for the site will be transferred back to Exelon, and the ISFSI will be maintained under Exelons Part 50 license (EC 2015).

As part of decommissioning, all above-grade structures, with a few exceptions, were demolished.

Structures below the 588-foot elevation (referenced from mean sea level), consisting primarily of exterior subgrade walls and floors, remain. These basement structures were backfilled as part of the final site restoration. In order to demonstrate compliance with the release criteria in 10 CFR 20.1402, ZS implemented final status survey (FSS) activities of remaining basement structures along with associated embedded piping and penetrations, buried piping, and remaining soil. FSS methodologies are outlined in Chapter 5 of ZSs license termination plan (LTP) (ZS 2018).

FSS methods are based on those outlined in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (NRC 2000). NRC issued license amendments 191 and 178 to approve ZSs LTP in September of 2018 (NRC 2018).

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NRC staff requested that the Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities within select impacted land areas of the site in order to use the confirmatory survey data for their evaluation of the adequacy and accuracy of ZSs FSS data as well as the final end state of the remaining land areas following backfill of several survey areas.

2. SITE DESCRIPTION ZNPS is located in Lake County, Illinois, on the easternmost portion of the city of Zion. It is approximately 64 kilometers (40 miles) north of Chicago, Illinois, and 68 kilometers (42 miles) south of Milwaukee, Wisconsin. The owner-controlled site is composed of approximately 134 hectares (330 acres) and is situated between the northern and southern parts of Illinois Beach State Park on the western shore of Lake Michigan (EC 2015 and ZS 2018). Figure 2.1 provides an overview of ZNPS. The site and its surrounding environs are relatively flat, with the elevation of the developed portion of the site at approximately 591 feet above mean seal level. For reference, the elevation of Lake Michiganwhich bounds the site on the eastis approximately 577.4 feet at low-water level (ZS 2018).

The area within the security-restricted fence contained the principal components of the power plant, including the two containment vessels, the turbine, crib house, and waste water treatment facility.

The site subdivided land areas into survey areas, which were further subdivided into individual FSS survey units (SUs). Note that some survey areas were not subdivided, and the survey area corresponds to the FSS SU. The survey areas are outlined in Figure 2.2.

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Figure 2.1. ZNPS Overview (adapted from ZS 2018)

Figure 2.2. Overview of ZNPS Survey Units (Adapted from NRC 2019)

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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 provided a formalized method for planning radiation surveys, improving survey efficiency and effectiveness, and ensuring that the type, quality, and quantity of data collected were adequate for the intended decision applications. The seven steps in the DQO process were as follows:

1. State the problem

2. Identify the decision/objective

3. Identify inputs to the decision/objective

4. Define the study boundaries

5. Develop a decision rule

6. Specify limits on decision errors

7. Optimize the design for obtaining data Confirmatory survey DQOs were originally presented in ORISE 2019 and are represented here for completeness.

3.1 STATE THE PROBLEM The first step in the DQO process defined the problem that necessitated the study. NRC requested that ORISE perform confirmatory surveys at ZNPS. The objectives of the confirmatory survey were to provide NRC staff with independent confirmatory data for NRCs consideration in the evaluation of the FSS results as well as the final end state of the remaining land areas following backfill of several survey areas. Therefore, the problem statement was as follows:

Confirmatory surveys are necessary to generate independent radiological data for NRC staffs consideration in the evaluation of the FSS design, implementation, and results 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 decision statements (DSs), and organized multiple decisions, as appropriate. This was done by specifying AAs that could result from a Yes response to the PSQs ZNPS Land Areas Confirmatory Survey Report 4 5271-SR-08-0

and combining the PSQs and AAs into a DS(s). Given that the problem statement introduced in Section 3.1 was fairly broad, multiple PSQs arose. PSQs, AAs, and combined DSs were organized based on the SU type (i.e., the associated FSS methodology), and are presented in Table 3.1.

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

Compile confirmatory data and report results to NRC staff for their decision making. Provide independent interpretation that confirmatory field surveys did not identify anomalous areas of residual radioactivity, quantitative field and laboratory data satisfied the NRC-approved decommissioning criteria, or that PSQ1: Do confirmatory survey results agree statistical sample population examination/assessment with the FSS data for the remaining land areas conditions were met.

and are residual radioactivity concentrations associated with the remaining land areas below No:

applicable limits? Compile confirmatory data and report results to NRC staff for their decision making. Provide independent interpretation of confirmatory survey results identifying any anomalous field or laboratory data or when statistical sample population examination/assessment conditions were not satisfied for NRC staffs determination of the adequacy and accuracy of the FSS data.

Yes:

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

PSQ2: Do the confirmatory results support the MARSSIM classification of the FSS SUs? No:

Confirmatory results do not support the classification of the FSS SUs. Summarize the discrepancies and provide technical comments to NRC staff for their decision making.

Decision Statements Determine if anomalous confirmatory survey results or other conditions are present that preclude the FSS data from demonstrating compliance with the release criteria.

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

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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 identified sampling and analytical methods that met data requirements. For this effort, information inputs included the following:

• ZNPS FSS data for remaining soils.

• Derived concentration guideline levels (DCGLs), further discussed in subsection 3.3.1.

• ORISE confirmatory survey results for gamma radiation surface scans.

• ORISE volumetric soil sample analytical results.

3.3.1 Radionuclides of Concern and Release Guidelines The primary radionuclides of concern (ROCs) identified for ZNPS are beta-gamma emitters fission and activation productsresulting from reactor operations. ZNPS developed site-specific DCGLs that correspond to a residual radioactive contamination level above background, which could result in a total effective dose equivalent (TEDE) of 25 millirem per year (mrem/yr) to an average member of the critical group. These DCGLsdefined in ZNPSs LTP as base case DCGLs (DCGLBCs)are radionuclide-specific and independently correspond to a TEDE of 25 mrem/yr for each source term. The initial suite of ROCs present at ZNPS has been reduced based on an insignificant dose contribution from a number of radionuclides. As such, the DCGLBCs have been reduced to account for the dose from these insignificant radionuclides.

In order to ensure that total dose from all site-related source termsbasement structures, soils, buried piping, and groundwateris less than the NRC-approved release criteria, the DCGLBCs are further reduced to operational DCGLs (DCGLOps). The DCGLOps represent the expected dose from prior investigations, and are used for remediation and FSS/remedial-action design purposes.

DCGLBCs and DCGLOps for surface and subsurface soil, accounting for insignificant dose contributors, are provided in Table 3.2. Note that ZS did not identify tritium (H-3) as a primary ROC. However, H-3 was included as part of this study, as requested by NRC staff.

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Table 3.2. ZNPS Soil DCGLsa and Corresponding MDCs (pCi/g)

Surface Soil DCGL Subsurface Soil DCGL ROC Base Case Operational Nominal Base Case Operational Analytical MDCc Scan MDCb Co-60 4.26 1.091 3 to 5 3.44 0.881 < 0.1 Cs-134 6.77 1.733 Unknown 4.44 1.137 < 0.1 Cs-137 14.18 3.630 6 to 8 7.75 1.984 < 0.1 Ni-63 3,572.10 914.458 HTD 763.02 195.333 <2 Sr-90 12.09 3.095 HTD 1.66 0.425 ~0.2 H-3 --d -- HTD -- -- <3 aRecreated from ZS 2018 bApproximated using the methods described in NRC 2000 cBased on observed analytical MDCs dH-3 is not identified as a primary ROC; therefore, DCGLs are not available pCi/g = picocuries per gram MDC = minimum detectible concentration HTD = hard-to-detect ROCs; scanning instrumentation not sensitive to these ROCs Because each individual DCGL represents a separate radiological dose, the sum-of-fractions (SOF) approach must be used to evaluate the total dose from the SU and demonstrate compliance with the dose limit. Since no areas of elevated activity exceeded the DCGLBC, Equation 4-3 from MARSSIM was used for SOF calculations:

Cj SOFTOTAL = SOFj =

=0 DCGLj

=0 where Cj is the concentration of ROC j and DCGLj is the DCGLOp and DCGLBC for ROC j.

Note that gross concentrations are considered here for conservatism and the SOF, based on the DCGLBC, also is presented for informational purposes.

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, and time for which separate decisions must be made.

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NRC prioritized confirmatory survey instigations for survey areas 10208 and 10214, along with SU 10209B.. ORISE investigated these priority survey areas/SU first and then focused on other areas as directed by NRC staff. Individual survey units were combined into larger confirmatory units (CUs) based on the MARSSIM classification, similar residual or background radiation conditions, physical characteristics, or other attributes. The survey areas prioritized by NRC staff were combined into 2 CUs: CU-1 composed of SUs 10208A, B, C, and D and 10209B and CU-3 composed of 10214A, B, C, D, E, and F. Furthermore, SU 12203A was identified as CU-2. Figure 3.1 shows the three CUs.

All land areas investigated were a MARSSIM Class 1, with the exception of 10214A, B, C, and D.

Additionally, NRC staff requested that ORISE collect sediment samples from storm water catch basins (CBs) within survey area 00150 for their evaluation. Survey area 00150 is a storm water drain system that was reclassified as a Class 2 from non-impacted after the discovery of site-related ROCs identified within the drainage piping.

Confirmatory surveys activities were conducted in the remaining land areas during December 2-5, 2019, and January 6-9, 2020, in 20 survey areas located within the security-restricted fence and two survey areas located outside the security-restricted fence.

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 FSS data and confirmatory data sets are in agreement with the second PSQ confirming the appropriateness of the SU classification.

Decision rules for each PSQ are discussed below.

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Figure 3.1. Confirmatory Units 1, 2, and 3 3.5.1 PSQ1: FSS and Confirmatory Data Agreement Confirmatory survey samples are not intended to demonstrate compliance with the release criterion directly, but, rather, 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 ZNPS Land Areas Confirmatory Survey Report 9 5271-SR-08-0

on collecting systematic data from specific survey areas and covering large areas of land with quality 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 contamination, and were typically compared to a single-point failure criterion (such as an elevated measurement comparison). Random samples were collected to compare against the random/systematic FSS data set. The intention of the comparison was to identify biaseseither positive or negativeand evaluate whether the bias could result in the incorrect decision to release a SU when it does not meet the release criterion. Bias between the data sets may be either systematic (i.e., one data set is consistently higher than the other) or discrete. The acceptable bias was dependent on numerous factors, which are discussed further in Section 3.6.1.

Generally, a positive bias between the confirmatory survey data and the FSS data is more of a concern than a negative bias. As such, confirmatory survey investigations described herein are designed to identify positive biasestypically through an appropriate statistical analysis. However, these formal statistical analyses are of limited use when the investigated SU contains radionuclide concentrations less than or approximately equal to the analytical minimum detectable concentration (MDC) (i.e., a visual comparison of the data sets is sufficient to determine if a significant bias is present that would influence the FSS results). NRC provided ORISE with preliminary FSS data for survey areas 10206, 10207, 10208, 12101, 12102, 12103, 12203, 12204, 12205, 12112, and 12113.

The data for these survey areas did not indicate the presence of significant radionuclide concentrations in excess of background levels. As a result, a simple random confirmatory data set was sufficient for evaluation of the FSS data. Additionally, this random data set provided NRC with an independent, unbiased estimate of the residual CU radiological concentrations. The decision rule addressing PSQ1 was stated as If unacceptable biases are not identified or each individual sample result is below the DCGLBC, then conclude that the FSS data are acceptable for demonstrating compliance with the release criterion; otherwise, perform further evaluation(s) and provide technical comments/recommendations to NRC for their evaluation and decision making.

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3.5.2 PSQ2: SU Classification The classification of the survey areas also was assessed as part of the confirmatory survey process based on the requirements outlined in the LTP, and primarily relates 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. FSS investigation levelsfor surface scans and quantitative measurements, such as soil sample analytical resultsthat trigger additional evaluations were established, and are presented in Section 5.6.4.6 of the LTP. These investigation levels are reproduced in Table 3.3. The site may perform additional remediation or reclassify and resurvey all or a portion of an SU. For confirmatory surveys, ORISE focused on identifying locations that potentially exceeded the soil sample investigation levels. These locations were used to confirm whether an SU should have been reclassified as part of the FSS process. The decision rule related to SU classification was stated as follows:

If soil concentrations indicate that a Class 2 or Class 3 should be reclassified to a higher classification, then summarize confirmatory data for NRC staffs evaluation and decision making.

Table 3.3. ZNPS Investigation Levels a SU Classification Soil Surface Scanning Investigation Levels Soil Sample Investigation Levels Class 1

> DCGLOp or > MDCSCAN if the MDCSCAN > DCGLOp Class 2 is greater than the DCGLOp Class 3 > 0.5

• DCGLOp aRecreated from ZS 2018 MDCSCAN = scan MDC 3.6 SPECIFY LIMITS ON DECISION ERRORS The sixth step in the DQO process examined the consequences of making an incorrect decision and established bounds of decision errors. Decision errors were controlled during the survey design, on-site field investigations, and the data assessment. There were two orders of control, each discussed in the subsections below.

3.6.1 Hypothesis Testing The first order of control was related to the evaluation of the FSS data relative to the confirmatory survey data. Hypothesis testing adopts a scientific approach where the survey data are used to select between the baseline condition (the null hypothesis, H0) and an alternative condition (the alternative ZNPS Land Areas Confirmatory Survey Report 11 5271-SR-08-0

hypothesis, HA). The null hypothesis, or the assumed base condition, was stated normally based on which base condition carries the greatest risk, such as releasing a contaminated area or, alternatively, expending budgeted resources on investigations of likely clean areas. The confirmatory survey was the last step in the site survey and investigation process. As such, the procedures and processes used to generate the FSS data received some level of review both by the licensee and NRC. Therefore, the null and alternative hypotheses were as follows:

H0: The confirmatory ROC concentration population mean/median (µCU) was less than or equal to the FSS mean/median (µFSS). Mathematically, the null hypothesis was stated as:

µCU - µFSS 0.

HA: The confirmatory ROC concentration population mean/median (µCU) was greater than the FSS mean/median (µFSS). Mathematically, the alternative hypothesis was stated as:

µCU - µFSS > 0.

For hypothesis testing, there were two types of decision errors to consider: Type I (typically designated as alpha, or ) and Type II (typically designated as beta, or ). A Type I error occurs when the null hypothesis is rejected when it should not be, also known as a false positive, and reflects the confidence level in the decision (confidence is defined as 1-). A Type II error is incorrectly failing to reject the null hypothesis when it is false, also known as a false negative. The ability to reject the null hypothesis when it is false is known as the power of the test (power is defined as 1-). The Type I error rate was set to 0.05 (i.e., there is a 5% chance of concluding the confirmatory population mean is greater than the FSS population mean when actually it is not). The a priori Type II error rate was no greater than 0.1 (i.e., there is no greater than a 10% chance of concluding the confirmatory population mean is less than the FSS population mean when actually it is greater). The actual Type II error rate, and subsequent power, achieved is dependent on the number of samples collected and the concentration variability in the sample set.

3.6.2 Field and Analytical MDCs The second order of control was to optimize the confirmatory field measurement and laboratory analytical MDCs. Field scanning and analytical MDCs were minimized by following the procedures referenced in Sections 4 and 5, respectively. As shown in Table 3.2, detector MDCSCANs for gamma-emitting ROCs were expected to be above the soil DCGLOps. Any anomalies above background ZNPS Land Areas Confirmatory Survey Report 12 5271-SR-08-0

identified while performing the surveys or subsequent data assessment were thoroughly investigated and discussed with NRC staff. Additionally, analytical MDCs were approximately 10% of the DCGLOpwith the exception of strontium-90 (Sr-90), which was approximately 50% of the DCGLOp, as indicated in Table 3.2.

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 within the accessible portions of the SUs requested by NRC staff during the periods of December 2-5, 2019, and January 6-9, 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 2019, ORAU 2016a, ORAU 2019a). Appendices C and D provide additional information regarding survey instrumentation and related processes discussed within this section.

4.1 REFERENCE SYSTEM ORISE referenced confirmatory measurement/sampling locations to global positioning system (GPS) coordinates using the Illinois East state plane 1201 NAD 1983 (meters). Measurement and sampling locations were documented on detailed survey maps.

4.2 SURFACE SCANS 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 for land areas. Accessible areas associated with the survey areas were scanned with medium- to high-density coverage. All detectors were coupled to Ludlum Model 2221 ratemeter-scalers with audible indicators. Ratemeter-scalers ZNPS Land Areas Confirmatory Survey Report 13 5271-SR-08-0

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. As the survey activities progressed, scan density was reduced to allow more survey areas to be scanned, as directed by NRC. Scan density was limited in some survey areas because of standing water and impassable muddy areas.

4.3 MEASUREMENT/SAMPLING LOCATIONS Soil samples were collected from both randomly- and judgmentally-selected locations. Two different soil sample data sets were generated: one for a formal, statistical comparison and one to estimate the mean. In both cases, 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 for each of the scenarios is discussed in the subsections below. The total number of judgmental measurements was based upon findings during gamma surface scans or NRC direction.

4.3.1 Simple Random Sampling (CU-2)

Simple random sampling was performed to generate the confirmatory data set used for the statistical comparison outlined in Section 3.6. The number of samples required to implement the test at the specified level of confidence/power depended on the radionuclide variability, which is the width of the gray region. For this effort, the gray region was considered to be the range of confirmatory mean/median radionuclide concentrations where decision errors are likely. As such, the width of the gray region was dependent on how large of a difference between the confirmatory survey data and FSS data would be tolerable before rejecting the null hypothesis. The upper bound of the gray region was no larger than the difference between the DCGL and the FSS SU mean. The SU radionuclide variability was used as inputs to the sample size calculation, resulting in 12 samples.

4.3.2 Ranked Set Sampling (CU-1 and CU-3)

A ranked-set-sampling (RSS) process, following EPA guidance, was used to select a sample set for an unbiased estimate of the mean (EPA 2002). 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 ZNPS Land Areas Confirmatory Survey Report 14 5271-SR-08-0

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. Conservative planning inputs for estimating the mean at the 95% confidence level within 0.2 units above/below the true mean yielded six samples (i.e., n = 6). Therefore, with six required soil samples, the number of repetitive cycles was 2 (r = n/m = 6/3 = 2). The total number of assessment locations per CU was defined as m2 x r (where r = 2 in this case), which was 32 x 2 = 18.

4.4 SOIL SAMPLING Surface soil sampling locations were randomly selected from the study area, as discussed in Sections 4.3.1 and 4.3.2. Seven locations were identified during surface scans with elevated direct gamma ZNPS Land Areas Confirmatory Survey Report 15 5271-SR-08-0

radiation levels distinguishable from background. However, as directed by NRC staff, only three judgmental samples were collected for analysis. The licensee investigated the other locations identified per NRCs request.

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. Subsurface samples were collected down to 0.5 meters or refusal at six RSS locations following the collection of the surface sample.

Surface soil samples were collected using clean hand trowels. Subsurface soil samples were collected using a manual soil auger. 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 Random Surface-Soil 12 Surface-Soil 12 RSS Subsurface-Soil 6 Random CB-Sedimenta 1 Surface-Soil 3 Judgmental CB-Sediment 3 Total 37 aCB = catch basin 4.5 SEDIMENT SAMPLING Four (three judgmental and one random) sediment samples were collected from storm water CBs located within survey area 00150. The judgmental samples were collected from CBs 5, 6, and 7 based on proximity to the former plant buildings. CB-9 was randomly selected from the balance of CBs.

Sediment samples were collected with a long-handled dipper. Water was removed, to the extent possible, prior to collection of the sample.

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 ZNPS Land Areas Confirmatory Survey Report 16 5271-SR-08-0

Laboratory (REAL) in Oak Ridge, Tennessee. Sample analyses were performed in accordance with the ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2019b). Soil samples were homogenized and analyzed by gamma spectrometry for gamma-emitting fission and activation products. Per NRC staff direction, six soil samples were analyzed for hard-to-detects (HTDs) Sr-90, nickel-63 (Ni-63), and H-3. One of the six samples was selected based on the gamma spectrometry results; the other five were randomly selected. Analytical results were reported in units of picocuries per gram (pCi/g).

Random soil sample 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. 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. Additionally, the FSS data were plotted along with the confirmatory data on a Q-plot to evaluate for biases. Biasespositive or negativewould be indicated by diverging data groupings.

Select soil sample analytical results also were plotted using strip charts, often referred to as one-dimensional scatter plots, and are further discussed in Section 6 as well.

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

6.1 SURFACE SCANS An overview of all the gamma walkover NaI detector response ranges for each SU investigated is illustrated in Figure A.1 in Appendix A. Figures A.2 through A.23 present the gamma walkover data for each survey area. Overall, the gamma responses ranged from approximately 1,100 counts per minute (cpm) to 38,000 cpm. Table 6.1 provides a summary of the notable results of the gamma walkover survey.

ZNPS Land Areas Confirmatory Survey Report 17 5271-SR-08-0

Table 6.1. Summary of Elevated Gamma Radiation Levels Identified During Scans NaI[Tl] Response (cpm)

Sample App. A SU Surrounding Notes Elevated Area Collected Figure Area 10208A-D 15,000 to 18,000 7,000 to 13,000 Yes A.7 Widespread area north of ISFSIa 10219 18,000 to 38,000 11,000 to 13,000 No A.12 Widespread area south of ISFSI 10209C 18,000 7,000 to 11,000 Yes A.8 Discrete area (<0.1 m2)b, concrete 10220I 11,000 to 13,000 5,000 to 7,000 No A.13 Localized area (~1 m2) 12112 20,000 5,000 to 9,000 No A.17 Discrete area (<0.5 m2) 12113 7,000 to 11,000 5,000 to 7,000 Yes A.18 Localized area (~1 m2) 12204A 38,000 5,000 to 7,000 No A.21 Discrete area (<0.1 m2), particlec aISFSI = independent spent fuel storage installation b m2 = square meter cThe ORISE NaI reading on the sample collected by ZionSolutions was > 500,000 cpm.

Higher gamma counts over a widespread area were experienced in survey areas near the ISFSI, such as the southern portions of survey areas 10208A-D and the northern portion of SU 10219. The ISFSI is known to have stored radioactive material; thus, elevated gamma count rates near the facility were not unexpected. Five other areas had elevated gamma radiation levels distinguishable from background: survey areas 10209C, 10220I, 12112, 12113, and 12204A. Two of the locations were localized (less than 1 square meter [m2]) and had slightly-elevated gamma radiation levels compared to surrounding gamma radiation levels, while the other three locations were discrete (0.1 to 0.5 m2) and had significantly-elevated gamma radiation levels compared to surrounding gamma radiation levels.

All seven locations were marked for further investigation or sampling. Initially, judgmental samples were collected as elevated areas were identified; however, as the survey activities progressed, NRC directed that samples not be collected by ORISE at identified elevated areas so that ORISE could maximize scan coverage. Instead, as directed by NRC staff, the site would investigate any areas identified with elevated radiation levels.

Because of instrumentation issues in the field, the gamma walkover data was not recorded in survey areas 10213, 12103, 12201, and 12203. No anomalies were noted in those survey areas during the gamma walkover survey.

6.2 RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES Figures A.24 through A.26 in Appendix A display the locations for the soil samples collected. Soil sample coordinates and pre- and post-sample static gamma counts are presented in Tables B.1, B.2, ZNPS Land Areas Confirmatory Survey Report 18 5271-SR-08-0

and B.3 in Appendix B. Analytical results for individual soil samples are presented in Tables B.4 through B.8.

Table 6.2 summarizes the ROC concentrations of the randomly-collected soil samples. All random samples collected from CUs 1, 2 and 3 had a SOF valuebased on the DCGLOpless than unity, which means that individual ROC concentrations were less than their respective DCLGOp. H-3 (in judgmental sample 5271S0075) and Ni-63 (in random sample 5271S0097) were the only HTD ROCs that were identified in the confirmatory soil samples above the analytical MDC. The random soil sample data sets in survey areas 10208 and 10209 (CU-1) and survey areas 10214 (CU-3) provided NRC with an unbiased estimate of the residual mean ROC concentration. Gamma shine from the ISFSI impacted the NaI measurements collected during the field ranking process, introducing ranking error. 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 CU-1, relative to what was planned, although the uncertainty is not greater than that resulting from the collection of six random samples. Because there was no significant residual contamination identified in the sample set for CU-1, the increased uncertainty does not limit confirmatory survey decisions. The confirmatory soil sample data set for SU 12203A (CU-2) was collected for evaluation against the FSS data set, as described below.

Table 6.2. Summary of ROC Concentrations in Random Confirmatory Soil Samples ROC Concentration (pCi/g)

Statistic SOFOpa,b Co-60 Cs-134 Cs-137 Ni-63 Sr-90 H-3 CU-1 (Survey Areas 10208 and 10209)c Min -0.006 -0.0031 0.005 -- -- -- <0.01 Max 0.022 0.016 0.04 -- -- -- 0.03 Mean 0.005 0.004 0.02 -- -- -- 0.01 St. Dev. 0.012 0.008 0.01 -- -- -- <0.01 CU-3 (Survey Area 10214) c Min -0.008 -0.0086 0.000 -- -- -- <0.01 Max 0.013 0.019 0.072 0.37 0.37 0.6 0.14 Mean 0.01 0.004 0.03 -- -- -- 0.04 St. Dev. 0.004 0.003 0.01 -- -- -- 0.02 CU-2 (SU 12203A)

Min -0.015 -0.0083 -0.029 0.26 -0.04 0.3 <0.01 Max 0.034 0.045 0.086 0.70 0.17 1.5 0.09 ZNPS Land Areas Confirmatory Survey Report 19 5271-SR-08-0

Table 6.2. Summary of ROC Concentrations in Random Confirmatory Soil Samples ROC Concentration (pCi/g)

Statistic SOFOpa,b Co-60 Cs-134 Cs-137 Ni-63 Sr-90 H-3 Mean 0.0008 0.009 0.01 -- -- -- 0.01 St. Dev. 0.01 0.02 0.03 -- -- -- 0.02 aThe SOF calculation does not include the fractional contribution of HTD radionuclides bSOF was calculated using the DCGLop cSample locations were selected using the RSS design process Figure 6.1 provides a Q-Q plot of gamma-emitting ROCs for the ORISE confirmatory data set and the Zion FSS data set. All soil sample concentrations for cesium-134 (Cs-134) were below the analytical MDC and will not be discussed further. Review of Figure 6.2 indicates that the ORISE data set distribution is biased lowor approximately equal, as is the case for Cs-137relative to the FSS data set below the first quantile. Above the first quantile, the Zion FSS data is positively biased.

Further evaluation via a formal statistical test is unnecessary because the data provided in Figure 6.1 indicate the ORISE confirmatory ROC concentration population is less than or equal to that of Zion.

Figure 6.1. Q-Q Plot for ORISE Confirmatory Survey and Zion FSS Soil Sample Results from CU-2 (SU 12203A)

Figure 6.2 presents a strip chart of the judgmental confirmatory soil sample concentration results.

Individual analytical results for judgmental surface soil samples are presented in Table B.7 in Appendix B. Soil sampling locations are illustrated on the maps in Figure A.24 through A.26 in ZNPS Land Areas Confirmatory Survey Report 20 5271-SR-08-0

Appendix A. One judgmental soil sample in SU 10209C was above the DCGLOp for Cs-137; however, the concentration was below the corresponding DCGLBC. This judgmental sample (5271S0075) represented the soil surrounding a piece of concrete debris that was identified as having elevated direct gamma radiation. As requested by NRC staff, the debris (collected as sample 5271S0074) was not submitted for laboratory analysis and was left with site personnel. A discrete area of elevated radiation was identified in SU 12204A. As directed by NRC, ORISE did not collect a sample; instead, site personnel investigated the area. The area was remediated as a result of the investigation. ORISE performed a post-sample collection gamma walkover scan to confirm the source of the elevated radiation was no longer present as shown in Figure A.22.

None of the ROC concentrations in the subsurface samples were above their respective analytical MDCs. Individual analytical results for the subsurface soil samples are presented in Table B.6.

Figure 6.2. Strip Chart for Confirmatory Survey Judgmental Soil Samples ZNPS Land Areas Confirmatory Survey Report 21 5271-SR-08-0

6.3 RADIONUCLIDE CONCENTRATIONS IN SEDIMENT SAMPLES Figure 6.3 presents a strip chart of the CB drain sediment sample concentration results. Individual analytical results for sediment samples are presented in Table B.8 in Appendix B. Sediment sampling locations are illustrated in Figure A.27 in Appendix A. Cs-137 was identified in concentrations above the analytical MDC in sediments collected from CB-6 (5271S0109), CB-5 (5271S0110), and CB-9 (5271S0111). Cobalt-60 (Co-60) was identified at a concentration above the analytical MDC in sediments collected from CB-9. All Cs-134 concentrations were less than the MDC. All gamma-emitting ROC concentrations in the sediment samples were less than 0.4 pCi/g.

Figure 6.3. Strip Chart for Confirmatory Survey Sediment Samples

7.

SUMMARY

AND CONCLUSIONS During the period of December 2-5, 2019 and January 6-9, 2020, ORISE performed independent confirmatory survey activities of surface and subsurface soils associated with the remaining land areas at ZNPS. The confirmatory surveys consisted of gamma walkover surface scans, gamma direct measurements, and surface and subsurface soil sampling. The areas investigated included all or a portion of survey areas 00150, 10201, 10202, 10203, 10206, 10207, 10208, 10209, 10211, 10213, 10214, 10219, 10220, 10221, 12102, 12103, 12112, 12113, 12201, 12203, 12204, and 12205.

ZNPS Land Areas Confirmatory Survey Report 22 5271-SR-08-0

Gamma scans identified seven areas of elevated radiation distinguishable from background. Two of these areas were to the north and south of the ISFSI. These areas had widespread, elevated gamma radiation levels that increased closer to the ISFSI, which was expected as it contains the sites spent fuel. Two other areas had slightly-elevated gamma radiation levels compared to surrounding gamma radiation levels, while the other three locations had significantly higher gamma radiation levels than the surrounding area.

Thirty-seven total soil samples were collected. Thirty sample locations were randomly selected, with 12 of the samples collected from CU-2 (SU 102203A) for a direct comparison against the FSS data, six random samples collected from CU-1 (survey areas 10208 and 10209), six random samples collected from CU-3 (survey areas 10214), and six samples to evaluate subsurface ROC concentrations in CU-1 (survey areas 10208 and 10209). Of the seven identified areas with elevated gamma radiation levels, three were judgmentally selected for sampling. One of the judgmentally sampled areas contained a piece of concrete-like debris, which was left with site personnel, while the soil from around the concrete was collected (5271S0075). The other three areas that were identified (excluding the area that was identified south of the ISFSI, which was attributed to gamma shine) were investigated by the site, as directed by NRC staff. One of the areas had a discrete radioactive particle that was responsible for the elevated direct gamma radiation. A gamma walkover scan was performed after the discrete particle was sampled, and showed gamma radiation levels to be similar to the surrounding area. ORISE does not have information related to the results of the other two areas investigated by the site in SU 10220I and 12112 because the FSS reports have not been finalized. Four samples also were collected from CB drains in SU 00150.

Based on the results of the collected confirmatory survey data, ORISE did not identify any anomalous issues that would preclude the FSS data from demonstrating compliance with the release criterion. Furthermore, the confirmatory survey data supports the SU classification. However, there are two locations, as mentioned previously, that conclusions cannot be made at this time because the site investigated these areas and the FSS reports are not available at this time. As such, it is recommended that NRC staff evaluate the results of these investigations. These areas are survey areas 10220I and 12112. Laboratory analyses for the sediment samples collected form the CBs in SU 00150 are presented for NRC staffs evaluation.

ZNPS Land Areas Confirmatory Survey Report 23 5271-SR-08-0

8. REFERENCES EC 2015. The Future of Zion. Webpage: http://www.exeloncorp.com/locations/power-plants/zion-station. Exelon Corporation. Chicago, Illinois. Accessed June 30, 2015.

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 2000. Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM). NUREG-1575.

Rev. 1. U.S. Nuclear Regulatory Commission. Washington, D.C. August.

NRC 2018. Zion Nuclear Power Station, Units 1 and 2 - Issuance of Amendments 191 and 178 for the Licenses to Approve the License Termination Plan. U.S. Nuclear Regulatory Commission. Washington, D.C.

September 28.

NRC 2019. E-mail communication between R. Edwards, NRC and N. Altic, ORISE. RE: Zion SU Map. April 9.

ORAU 2014. ORAU Radiation Protection Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. October.

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

ORAU 2016b. ORAU Health and Safety Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. January.

ORISE 2019. Project-Specific Plan for the Confirmatory Survey Activities of Land Areas at the Zion Nuclear Power Station, Zion, Illinois. Oak Ridge Institute for Science and Education. Oak Ridge, Tennessee. November 26.

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

ORAU 2019b. ORAU Radiological and Environmental Analytical Laboratory Procedures Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. June 27.

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

ZS 2018. Zion Station Restoration Project License Termination Plan, Rev. 2. ZionSolutions, LLC.

Chicago, Illinois. February 7.

ZNPS Land Areas Confirmatory Survey Report 24 5271-SR-08-0

APPENDIX A: FIGURES ZNPS Land Areas Confirmatory Survey Report 5271-SR-08-0

ISFSI Figure A.1. Gamma Walkover Coverage for All Survey Areas Investigated (Overview)

ZNPS Land Areas Confirmatory Survey Report A-1 5271-SR-08-0

Figure A.2. Gamma Walkover Data for Survey Area 10201 ZNPS Land Areas Confirmatory Survey Report A-2 5271-SR-08-0

Figure A.3. Gamma Walkover Data for Survey Area 10202 ZNPS Land Areas Confirmatory Survey Report A-3 5271-SR-08-0

Figure A.4. Gamma Walkover Data for Survey Area 10203 ZNPS Land Areas Confirmatory Survey Report A-4 5271-SR-08-0

Figure A.5. Gamma Walkover Data for Survey Area 10206 ZNPS Land Areas Confirmatory Survey Report A-5 5271-SR-08-0

Figure A.6. Gamma Walkover Data for Survey Area 10207 ZNPS Land Areas Confirmatory Survey Report A-6 5271-SR-08-0

Figure A.7. Gamma Walkover Data for Survey Area 10208 ZNPS Land Areas Confirmatory Survey Report A-7 5271-SR-08-0

Figure A.8. Gamma Walkover Data for Survey Area 10209 ZNPS Land Areas Confirmatory Survey Report A-8 5271-SR-08-0

Figure A.9. Gamma Walkover Data for Survey Area 10211 ZNPS Land Areas Confirmatory Survey Report A-9 5271-SR-08-0

Figure A.10. Gamma Walkover Data for Survey Area 10213 ZNPS Land Areas Confirmatory Survey Report A-10 5271-SR-08-0

Figure A.11. Gamma Walkover Data for Survey Area 10214 ZNPS Land Areas Confirmatory Survey Report A-11 5271-SR-08-0

Figure A.12. Gamma Walkover Data for Survey Area 10219 ZNPS Land Areas Confirmatory Survey Report A-12 5271-SR-08-0

Figure A.13. Gamma Walkover Data for Survey Area 10220 ZNPS Land Areas Confirmatory Survey Report A-13 5271-SR-08-0

Figure A.14. Gamma Walkover Data for Survey Area 10221 ZNPS Land Areas Confirmatory Survey Report A-14 5271-SR-08-0

Figure A.15. Gamma Walkover Data for SU 12102 ZNPS Land Areas Confirmatory Survey Report A-15 5271-SR-08-0

Figure A.16. Gamma Walkover Data for SU 12103 ZNPS Land Areas Confirmatory Survey Report A-16 5271-SR-08-0

Figure A.17. Gamma Walkover Data for SU 12112 ZNPS Land Areas Confirmatory Survey Report A-17 5271-SR-08-0

Figure A.18. Gamma Walkover Data for SU 12113 ZNPS Land Areas Confirmatory Survey Report A-18 5271-SR-08-0

Figure A. 19. Gamma Walkover Data for Survey Area 12201 ZNPS Land Areas Confirmatory Survey Report A-19 5271-SR-08-0

Figure A.20. Gamma Walkover Data for Survey Area 12203 ZNPS Land Areas Confirmatory Survey Report A-20 5271-SR-08-0

Figure A.21. Gamma Walkover Data for Survey Area 12204 ZNPS Land Areas Confirmatory Survey Report A-21 5271-SR-08-0

Figure A.22. Gamma Walkover Data for SU 12204A Post-Remediation ZNPS Land Areas Confirmatory Survey Report A-22 5271-SR-08-0

Figure A.23. Gamma Walkover Data for Survey Area 12205 ZNPS Land Areas Confirmatory Survey Report A-23 5271-SR-08-0

Note: Both surface and subsurface samples were collected at random locations.

Figure A.24. CU-1 Sample Locations and SU 10209C Judgmental Sample Location ZNPS Land Areas Confirmatory Survey Report A-24 5271-SR-08-0

Figure A.25. CU-2 Sample Locations and SU 12113 Judgmental Sample Location ZNPS Land Areas Confirmatory Survey Report A-25 5271-SR-08-0

Figure A.26. CU-3 Sample Locations ZNPS Land Areas Confirmatory Survey Report A-26 5271-SR-08-0

Figure A.27. SU 00150 Sediment Sample Locations ZNPS Land Areas Confirmatory Survey Report A-27 5271-SR-08-0

APPENDIX B: DATA TABLES ZNPS Land Areas Confirmatory Survey Report 5271-SR-08-0

Table B.1. Surface Soil Sample Locations and Gamma Measurements Coordinates (m) Gamma Measurement (cpm) Sample Depth RSS ID Survey Unit Sample ID Easting Northing Pre-Sample Post-Sample (cm)

CU-1 (Survey Areas 10208 and 10209) 1-1-1 10209B 343558 641580 -- 9,872 -- --

1-1-2 10208D 343531 641680 5271S0077 7,041 6,194 0-15 1-1-3 10208B 343484 641656 -- 11,077 -- --

1-2-1 10208A 343469 641676 -- 8,065 -- --

1-2-2 10208D 343504 641594 5271S0079 8,897 8,768 0-15 1-2-3 10208D 343509 641611 -- 10,617 -- --

1-3-1 10208C 343483 641589 5271S0081 13,223 13,801 0-15 1-3-2 10208D 343517 641625 -- 9,139 -- --

1-3-3 10208D 343523 641677 -- 7,812 -- --

2-1-1 10208B 343476 641640 -- 12,369 -- --

2-1-2 10208C 343512 641673 -- 8,368 -- --

2-1-3 10208D 343521 641642 5271S0078 7,998 7,198 0-15 2-2-1 10209B 343557 641615 -- 6,984 -- --

2-2-2 10208A 343463 641610 -- 15,301 -- --

2-2-3 10209B 343552 641606 5271S0076 7,288 6,612 0-15 2-3-1 10208C 343501 641617 5271S0080 11,419 10,224 0-15 2-3-2 10208A 343474 641681 -- 9,664 -- --

2-3-3 10208A 343464 641625 -- 9,771 -- --

CU-3 (Survey Areas 10214) 1-1-1 10214 343443 642083 5271S0106 2,955 3,728 0-15 1-1-2 10214 343561 642148 -- 3,410 -- --

1-1-3 10214 343620 642104 -- 4,456 -- --

1-2-1 10214 343472 642170 -- 3,028 -- --

ZNPS Land Areas Confirmatory Survey Report B-1 5271-SR-08-0

Table B.1. Surface Soil Sample Locations and Gamma Measurements Coordinates (m) Gamma Measurement (cpm) Sample Depth RSS ID Survey Unit Sample ID Easting Northing Pre-Sample Post-Sample (cm) 1-2-2 10214 343590 642061 5271S0103 2,971 3,164 0-15 1-2-3 10214 343531 642126 -- 2,669 -- --

1-3-1 10214 343542 642090 5271S0104 3,500 3,290 0-8 1-3-2 10214 343483 642155 -- 2,884 -- --

1-3-3 10214 343601 642047 -- 2,945 -- --

2-1-1 10214 343454 642112 -- 3,085 -- --

2-1-2 10214 343572 642177 -- 3,795 -- --

2-1-3 10214 343513 642068 5271S0105 3,023 3,156 0-8 2-2-1 10214 343631 642133 -- 2,878 -- --

2-2-2 10214 343498 642071 5271S0107 2,992 3,010 2-2-3 10214 343616 642137 -- 3,132 -- --

2-3-1 10214 343587 642093 -- 2,617 -- --

2-3-2 10214 343528 642158 -- 2,871 -- --

2-3-3 10214 343646 642050 5271S0102 3,957 6,332 0-15 CU-2 (SU 12203A)

-- 12203A 343646 641621 5271S0089 7,704 10,927 0-15

-- 12203A 343662 641627 5271S0090 5,258 5,570 0-15

-- 12203A 343663 641634 5271S0091 6,519 7,215 0-15

-- 12203A 343655 641637 5271S0092 6,290 6,616 0-15

-- 12203A 343651 641642 5271S0093 7,694 8,288 0-15

-- 12203A 343668 641644 5271S0094 8,410 10,137 0-15

-- 12203A 343677 641660 5271S0095 8,802 12,070 0-15

-- 12203A 343672 641666 5271S0096 9,200 11,914 0-15

-- 12203A 343674 641681 5271S0097 7,669 11,272 0-15

-- 12203A 343666 641677 5271S0098 4,164 3,530 0-15

-- 12203A 343657 641670 5271S0099 8,748 11,515 0-15 ZNPS Land Areas Confirmatory Survey Report B-2 5271-SR-08-0

Table B.1. Surface Soil Sample Locations and Gamma Measurements Coordinates (m) Gamma Measurement (cpm) Sample Depth RSS ID Survey Unit Sample ID Easting Northing Pre-Sample Post-Sample (cm)

-- 12203A 343671 641666 5271S0100 9,192 11,350 0-15 Table B.2. CU-1 Subsurface Soil Sample Locations and Gamma Measurements Coordinates (m) Gamma Measurement (cpm) Sample Depth RSS ID Survey Unit Sample ID Easting Northing Pre-Sample Post-Sample (cm) 1-2-2 10208D 343504 641594 5271S0083 8,768 3,251 15-50 2-3-1 10208C 343501 641617 5271S0084 11,325 15,583 15-50 1-3-1 10208C 343483 641589 5271S0085 11,144 5,092 15-50 2-1-3 10208D 343521 641642 5271S0086 8,084 7,806 15-50 1-1-2 10208D 343531 641680 5271S0087 6,150 7,239 15-50 2-2-3 10209B 343552 641606 5271S0088 7,686 7,757 15-50 Table B.3. Judgmental Surface Soil Sample Locations and Gamma Measurements Coordinates (m) Gamma Measurement (cpm) Sample Depth Survey Unit Sample ID Easting Northing Pre-Sample Post-Sample (cm) 10209C 343570 641585 5271S0075 26,247 7,643 0-15 10208A 343450 641614 5271S0082 24,393 17,763 0-15 12113 343729 641686 5271S0101 7,492 9,972 0-15 ZNPS Land Areas Confirmatory Survey Report B-3 5271-SR-08-0

ZNPS Land Areas Confirmatory Survey Report B-4 5271-SR-08-0

Table B.4. ROC Concentrations in CU-1 and CU-3 Co-60 (pCi/g) Cs-134 (pCi/g) Cs-137 (pCi/g) Ni-63 (pCi/g) Sr-90 (pCi/g) H-3(pCi/g) SOFa Sample ID Conc. b TPUc MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU CU-1 (Survey Areas 10208 and 10209) 5271S0076 0.016 0.017 0.039 0.013 0.018 0.039 0.017 0.013 0.029 -- -- -- -- -- -- -- -- 0.03 0.01 5271S0077 0.004 0.014 0.030 0.000 0.013 0.028 0.005 0.011 0.026 -- -- -- -- -- -- -- -- -- 0.01 <0.01 5271S0078 -0.004 0.020 0.040 0.016 0.015 0.038 0.009 0.014 0.034 -- -- -- -- -- -- -- -- -- 0.01 <0.01 5271S0079 0.022 0.013 0.035 0.000 0.004 0.028 0.040 0.010 0.020 -- -- -- -- -- -- -- -- -- 0.03 0.01 5271S0080 -0.003 0.012 0.024 -0.003 0.006 0.029 0.016 0.013 0.028 -- -- -- -- -- -- -- -- -- <0.01 <0.01 5271S0081 -0.006 0.020 0.039 0.001 0.005 0.042 0.007 0.012 0.039 -- -- -- -- -- -- -- -- -- <0.01 <0.01 CU-3 (Survey Areas 10214) 5271S0102 0.009 0.022 0.044 0.019 0.022 0.046 0.072 0.018 0.030 -- -- -- -- -- -- -- -- -- 0.04 0.01 5271S0103 0.013 0.013 0.030 0.007 0.015 0.030 0.017 0.015 0.032 0.37 0.41 0.68 0.37 0.27 0.44 0.6 1.7 2.9 0.14 0.04 5271S0104 0.011 0.043 0.085 0.003 0.011 0.087 0.023 0.042 0.084 -- -- -- -- -- -- -- -- -- 0.02 0.01 5271S0105 -0.008 0.014 0.027 -0.009 0.009 0.035 0.000 0.013 0.032 -- -- -- -- -- -- -- -- -- <0.01 <0.01 5271S0106 0.012 0.020 0.045 -0.006 0.009 0.043 0.051 0.022 0.045 -- -- -- -- -- -- -- -- -- 0.03 0.01 5271S0107 -0.003 0.011 0.023 0.009 0.012 0.029 0.006 0.010 0.023 -- -- -- -- -- -- -- -- -- 0.01 <0.01 a The SOF calculation does not include the fractional contributions from HTD ROC, unless sample analysis was completed for these radionuclides bResults greater than MDC are bolded cUncertainties are based on total propagated uncertainties at the 95% confidence level Conc. = concentration TPU = total unpropagated uncertainty MDC = minimum detectable concentration pCi/g = picocuries per gram ZNPS Land Areas Confirmatory Survey Report B-5 5271-SR-08-0

Table B.5. Radionuclide Concentration in CU-2 (SU 12203A) Soil Samples Co-60 (pCi/g) Cs-134 (pCi/g) Cs-137 (pCi/g) Ni-63 (pCi/g) Sr-90 (pCi/g) H-3(pCi/g) SOFa Sample ID Conc. TPUb MDC Conc. TPU MDC Conc.c TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU 5271S0089 -0.002 0.027 0.054 -0.002 0.009 0.063 0.008 0.022 0.026 -- -- -- -- -- -- -- -- -- <0.01 <0.01 5271S0090 0.007 0.006 0.022 0.026 0.022 0.047 0.040 0.017 0.036 -- -- -- -- -- -- -- -- -- 0.03 0.01 5271S0091 0.010 0.018 0.038 0.000 0.006 0.041 0.038 0.018 0.039 -- -- -- -- -- -- -- -- -- 0.02 0.01 5271S0092 0.034 0.016 0.034 -0.004 0.009 0.041 0.086 0.020 0.037 -- -- -- -- -- -- -- -- -- 0.06 0.01 5271S0093 0.010 0.021 0.046 0.026 0.022 0.049 0.009 0.008 0.029 0.26 0.41 0.69 -0.04 0.13 0.25 1.5 1.7 2.9 0.03 0.01 5271S0094 -0.015 0.029 0.055 -0.005 0.008 0.062 -0.028 0.026 0.051 -- -- -- -- -- -- -- -- -- <0.01 <0.01 5271S0095 -0.010 0.024 0.048 -0.005 0.013 0.062 -0.029 0.021 0.045 -- -- -- -- -- -- -- -- -- <0.01 <0.01 5271S0096 0.000 0.032 0.059 0.045 0.031 0.066 -0.001 0.021 0.058 -- -- -- -- -- -- -- -- -- 0.03 0.01 5271S0097 -0.001 0.035 0.065 0.043 0.020 0.041 0.043 0.020 0.041 0.70 0.40 0.66 0.17 0.15 0.25 0.3 1.5 2.6 0.10 0.02 5271S0098 0.002 0.014 0.029 -0.003 0.006 0.030 0.016 0.013 0.029 -- -- -- -- -- -- -- -- -- 0.01 0.00 5271S0099 -0.013 0.030 0.058 0.000 0.012 0.071 0.007 0.018 0.052 -- -- -- -- -- -- -- -- -- <0.01 <0.01 5271S0100 -0.012 0.032 0.063 -0.008 0.009 0.071 -0.015 0.030 0.061 -- -- -- -- -- -- -- -- -- <0.01 <0.01 a The SOF calculation does not include the fractional contributions from HTD ROC, unless sample analysis was completed for these radionuclides b Uncertainties are based on total propagated uncertainties at the 95% confidence level cResults greater than MDC are bolded Conc. = concentration TPU = total propagated uncertainty MDC = minimum detectable concentration pCi/g = picocuries per gram ZNPS Land Areas Confirmatory Survey Report B-6 5271-SR-08-0

Table B.6. ROC Concentrations in CU-1 (Survey Areas 10208 and 10209) Subsurface Soil Samples Co-60 (pCi/g) Cs-134 (pCi/g) Cs-137 (pCi/g) Ni-63 (pCi/g) Sr-90 (pCi/g) H-3(pCi/g) SOFa Sample ID Conc. TPUb MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Op BC 5271S0083 0.004 0.015 0.032 -0.002 0.006 0.029 0.003 0.010 0.024 -- -- -- -- -- -- -- -- -- 0.01 <0.01 5271S0084 -0.010 0.026 0.051 0.023 0.025 0.057 -0.003 0.022 0.045 -- -- -- -- -- -- -- -- -- 0.02 0.01 5271S0085 0.006 0.014 0.040 -0.003 0.021 0.039 0.018 0.013 0.028 -- -- -- -- -- -- -- -- -- 0.02 <0.01 5271S0086 0.002 0.014 0.030 0.000 0.006 0.035 0.012 0.008 0.027 -- -- -- -- -- -- -- -- -- 0.01 <0.01 5271S0087 0.003 0.018 0.039 0.028 0.018 0.046 0.004 0.014 0.035 -- -- -- -- -- -- -- -- -- 0.03 0.01 5271S0088 -0.002 0.005 0.038 0.013 0.021 0.042 0.012 0.013 0.037 0.23 0.41 0.69 0.03 0.15 0.27 0.6 1.7 2.9 0.09 0.02 a The SOF calculation does not include the fractional contributions from HTD ROC; unless sample analysis was completed for these radionuclides bUncertainties are based on total propagated uncertainties at the 95% confidence level.

Conc. = concentration TPU = total propagated uncertainty MDC = minimum detectable concentration Table B.7. ROC Concentrations in Judgmental Soil Samples Co-60 (pCi/g) Cs-134 (pCi/g) Cs-137 (pCi/g) Ni-63 (pCi/g) Sr-90 (pCi/g) H-3(pCi/g) SOFa Sample ID Conc. TPUb MDC Conc. TPU MDC Conc.c TPU MDC Conc. TPU MDC Conc. TPU MDC Conc. TPU MDC Op BC 5271S0075 0.007 0.021 0.033 0.050 0.023 0.060 7.25 0.79 0.06 0.63 0.42 0.69 0.00 0.26 0.47 9.3 1.8 2.5 2.03 0.52 5271S0082 0.024 0.006 0.035 -0.006 0.007 0.050 0.088 0.021 0.035 0.67 0.41 0.68 -0.07 0.26 0.48 2.3 2.1 3.5 0.05 0.01 5271S0101 0.014 0.029 0.057 0.027 0.033 0.067 0.024 0.011 0.037 -- -- -- -- -- -- -- -- -- 0.04 0.01 a The SOF calculation does not include the fractional contributions from HTD ROC, unless sample analysis was completed for these radionuclides bUncertainties are based on total propagated uncertainties at the 95% confidence level cResults greater than MDC are bolded Conc. = concentration TPU = total propagated uncertainty MDC = minimum detectable concentration ZNPS Land Areas Confirmatory Survey Report B-7 5271-SR-08-0

Table B.8. ROC Concentrations in Sediment Samples Co-60 (pCi/g) Cs-134 (pCi/g) Cs-137 (pCi/g)

Sample ID Location Conc.a TPUb MDC Conc. TPU MDC Conc. TPU MDC 5271S0108 CB-7 0.009 0.012 0.026 0.010 0.015 0.031 0.017 0.009 0.020 5271S0109 CB-6 0.007 0.013 0.029 0.013 0.013 0.031 0.053 0.016 0.029 5271S0110 CB-5 0.038 0.050 0.117 0.051 0.044 0.108 0.320 0.061 0.097 5271S0111 CB-9 0.053 0.021 0.040 -0.005 0.006 0.052 0.145 0.028 0.043 a Results greater than MDC are bolded.

b Uncertainties are based on total propagated uncertainties at the 95% confidence level.

CB = catch basin Conc. = concentration TPU = total propagated uncertainty MDC = minimum detectable concentration ZNPS Land Areas Confirmatory Survey Report B-8 5271-SR-08-0

APPENDIX C: MAJOR INSTRUMENTATION ZNPS Land Areas Confirmatory Survey Report 5271-SR-08-0

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 (Ludlum Measurements, Inc., Sweetwater, Texas)

Coupled to: Ludlum Ratemeter-scaler Model 2221 (Ludlum Measurements, Inc., Sweetwater, Texas)

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

C.2. LABORATORY ANALYTICAL INSTRUMENTATION Low-Background Gas Proportional Counter Series 5 XLB (Canberra, Meriden, Connecticut)

Used in conjunction with:

Eclipse Software Dell Workstation (Canberra, Meriden, Connecticut)

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-45200-5 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)

ZNPS Land Areas Confirmatory Survey Report C-1 5271-SR-08-0

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)

Liquid Scintillation Counter Perkin Elmer Tricarb 5110TR (Perkin Elmer, Waltham, Massachusetts)

ZNPS Land Areas Confirmatory Survey Report C-2 5271-SR-08-0

APPENDIX D: SURVEY AND ANALYTICAL PROCEDURES ZNPS Land Areas Confirmatory Survey Report 5271-SR-08-0

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 2014, ORAU 2016a, and ORAU 2016b). 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 2019a)

• ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2019b)

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.

Quality control procedures include

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

ZNPS Land Areas Confirmatory Survey Report D-1 5271-SR-08-0

• 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 the detector 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. 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.

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. Subsurface soil samples were collected using a manual soil auger. The entire 15-centimeter (cm) to 50-cm depth interval was collected in 2-gallon plastic bags and homogenized in the field and then a portion was given to ZionSolutions. The remaining soil was retained by ORISE. All containers were labeled and security sealed in accordance with ORISE procedures. ZionSolutions shipped the samples under chain-of-custody to the ORISE laboratory for analysis.

D.4. RADIOLOGICAL ANALYSIS D.4.1 GAMMA SPECTROSCOPY Samples were analyzed as received and homogenized or crushed, 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-ZNPS Land Areas Confirmatory Survey Report D-2 5271-SR-08-0

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 Co-60 1.332 0.06 Cs-134 0.795 0.06 Cs-137 0.662 0.05 aSpectra also were reviewed for other identifiable TAPs.

bMeV = mega electron volt cpicocurie per gram D.4.2 RADIOACTIVE STRONTIUM ANALYSIS Strontium-90 (Sr-90) concentrations were quantified by total sample dissolution followed by radiochemical separation, and were counted on a low-background gas proportional counter. Samples were homogenized and dissolved by a combination of potassium hydrogen fluoride and pyrosulfate fusions. The fusion cakes were dissolved, and strontium was co-precipitated on lead sulfate. The sulfate-salt complex was dissolved in ethylenediaminetetraacetic acid (EDTA) at a pH of 8.0. The strontium was separated from residual calcium and lead by re-precipitating strontium sulfate from EDTA at a pH of 4.0. Strontium was separated from barium by complexing the strontium in diethylenetriaminepentaacetic acid (DTPA) while precipitating barium as barium chromate. The strontium was ultimately converted to strontium carbonate and counted on a low-background gas proportional counter. The typical MDC for a 60-minute count time using this procedure is 0.4-0.6 pCi/g for a 1-gram sample.

D.4.3 H-3 ANALYSIS Tritium (H-3) analysis for the soil samples was performed using a material oxidizer, and counted by liquid scintillation. The material oxidizer combusts samples in a stream of oxygen gas and passes the products (including carbon dioxide and water vapor), through a series of catalysts. H-3 is carried by ZNPS Land Areas Confirmatory Survey Report D-3 5271-SR-08-0

water and is captured in a trapping scintillation cocktail specific to water. The typical MDC for H-3 for a 60-minute count time using this procedure is 3-5 pCi/g.

D.4.4 NI-63 ANALYSIS Soil samples were spiked with a nickel (Ni) and cobalt carrier and digested with a mixture of nitric and hydrochloric acids. Unwanted elements, such as iron and cobalt, then were removed by running the slurry via anion exchange chromatography. Nickel was then separated from the slurry using a nickel selective resin cartridge. The purified nickel then was eluted off of the column with a dilute nitric acid solution. Ni-63 activity then was determined via liquid scintillation counting. The typical MDC for a 1-gram sample and 60-minute count time using this procedure is 1.8 pCi/g.

D.4.5 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.

ZNPS Land Areas Confirmatory Survey Report D-4 5271-SR-08-0