ML23107A273

Orise Independent Survey Report Dcn 5366-SR-01-0

ML23107A273
Person / Time
Site:	Crystal River
Issue date:	06/07/2023
From:	Bailey E Oak Ridge Institute for Science & Education
To:	Jack Parrott Reactor Decommissioning Branch
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ML23107A271	List: ML23107A272 ML23107A273
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eConcurrence 20230417-20018, DCN 5366-SR-01-0
Download: ML23107A273 (43)

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June 7, 2023 Mr. Jack Parrott, Sr. Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Materials and Safeguards Division of Decommissioning, Uranium Recovery, and Waste Programs TWFN Mail Stop T-8F5 Rockville, MD 20852

SUBJECT:

CONFIRMATORY SURVEY ACTIVITIES

SUMMARY

AND RESULTS FOR THE EAST SETTLING POND AT THE CRYSTAL RIVER UNIT 3 NUCLEAR GENERATING PLANT, CRYSTAL RIVER, FLORIDA; DOCKET NUMBER 50-302; RFTA 22-005; DCN: 5366-SR-01-1

Dear Mr. Parrott:

The Oak Ridge Institute for Science and Education (ORISE) is pleased to provide the enclosed revised final report detailing the confirmatory survey activities and results performed for the East Settling Pond at the Crystal River Unit 3 Nuclear Generating Plant in Crystal River, Florida.

Please feel free to contact me at Erika.Bailey@orau.org if you have any comments or concerns.

Sincerely, Erika N. Bailey Survey Projects Manager ORISE ENB:enb electronic distribution:

T. Barvitskie, NRC L. Parks, NRC S. Giebel, NRC S. Anderson, NRC C. Dennes, NRC K. Engel, ORISE D. Hagemeyer, ORISE File/5366 100 ORAU Way

• Oak Ridge

• TN 37830

• orise.orau.gov

CONFIRMATORY SURVEY ACTIVITIES

SUMMARY

AND RESULTS FOR THE EAST SETTLING POND AT THE CRYSTAL RIVER UNIT 3 NUCLEAR GENERATING PLANT, CRYSTAL RIVER, FLORIDA K. M. Engel ORISE FINAL REPORT Prepared for the U.S. Nuclear Regulatory Commission June 2023 DCN 5366-SR-01-1 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.

CR3 East Settling Pond Confirmatory Survey Report 5366-SR-01-1 CONFIRMATORY SURVEY ACTIVITIES

SUMMARY

AND RESULTS FOR THE EAST SETTLING POND AT THE CRYSTAL RIVER UNIT 3 NUCLEAR GENERATING PLANT, CRYSTAL RIVER, FLORIDA FINAL REPORT Prepared by K. M. Engel ORISE June 2023 Prepared for the U.S. Nuclear Regulatory Commission This document was prepared for the U.S. Nuclear Regulatory Commission (NRC) by the Oak Ridge Institute for Science and Education (ORISE) through Interagency Agreement 31310021S0033 between the NRC and the U.S. Department of Energy (DOE). ORISE is managed by Oak Ridge Associated Universities under DOE contract number DE-SC0014664.

CR3 East Settling Pond Confirmatory Survey Report i

5366-SR-01-1 CONFIRMATORY SURVEY ACTIVITIES

SUMMARY

AND RESULTS FOR THE EAST SETTLING POND AT THE CRYSTAL RIVER UNIT 3 NUCLEAR GENERATING PLANT, CRYSTAL RIVER, FLORIDA Prepared by:

Date:

6/7/2023 K. M. Engel, CHP, Health Physicist ORISE Reviewed by:

Date:

6/7/2023 E. N. Bailey, Survey Projects Manger ORISE Reviewed by:

Date:

6/7/2023 P. H. Benton, Quality Manager ORISE Reviewed and approved for release by:

Date:

6/7/2023 Derek Hagemeyer, Director, IEAV ORISE FINAL REPORT June 2023

CR3 East Settling Pond Confirmatory Survey Report ii 5366-SR-01-1 CONTENTS FIGURES.......................................................................................................................................................... iv TABLES............................................................................................................................................................. iv ACRONYMS..................................................................................................................................................... v

1. INTRODUCTION....................................................................................................................................... 1

2. SITE DESCRIPTION................................................................................................................................. 1

3. DATA QUALITY OBJECTIVES............................................................................................................. 4 3.1 State the Problem.............................................................................................................................. 4 3.2 Identify the Decision/Objective..................................................................................................... 5 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.................................................................................................................. 7 3.5.1 PSQ1: Characterization and Confirmatory Data Agreement............................................. 8 3.5.2 PSQ2: SU Classification........................................................................................................... 8 3.6 Specify Limits on Decision Errors................................................................................................. 9 3.6.1 Hypothesis Testing................................................................................................................... 9 3.6.2 Field and Analytical Minimum Detectable Concentrations.............................................. 10 3.7 Optimize the Design for Obtaining Data.................................................................................... 10

4. PROCEDURES.......................................................................................................................................... 11 4.1 Reference System............................................................................................................................ 11 4.2 Surface Scans.................................................................................................................................... 11 4.3 Measurement/Sampling Locations............................................................................................... 11 4.4 Soil Sampling.................................................................................................................................... 13

5. SAMPLE ANALYSIS AND DATA INTERPRETATION............................................................... 13

6. FINDINGS AND RESULTS................................................................................................................... 14 6.1 Surface Scans.................................................................................................................................... 14 6.2 Radionuclide Concentrations in Soil Samples............................................................................. 15

7.

SUMMARY

AND CONCLUSIONS...................................................................................................... 20

8. REFERENCES........................................................................................................................................... 21 APPENDIX A: FIGURES APPENDIX B: DATA TABLES

CR3 East Settling Pond Confirmatory Survey Report iii 5366-SR-01-1 APPENDIX C: MAJOR INSTRUMENTATION APPENDIX D: SURVEY AND ANALYTICAL PROCEDURES

CR3 East Settling Pond Confirmatory Survey Report iv 5366-SR-01-1 FIGURES Figure 2.1. Aerial View of the CREC.............................................................................................................. 2 Figure 2.2. CR3 Preliminary Classifications of Radiological Impacts in Outlying Areas Settling Ponds

.............................................................................................................................................................................. 3 Figure 2.3. SU WOCZ-01 Boundary.............................................................................................................. 3 Figure 6.1. Q Plot of Confirmatory Gamma Scan Data from WOCZ-01 East Settling Pond............ 15 Figure 6.2. Strip Charts for the Sites and Confirmatory Random Soil Sample Results........................ 19 TABLES Table 3.1. Independent Confirmatory Survey Decision Process................................................................ 5 Table 3.2. CR3 Soil DCGLs............................................................................................................................. 6 Table 3.3. CREC Investigation Levels............................................................................................................ 9 Table 6.1. Descriptive Statistics for ROC Concentrations in Random Soil Samples............................ 17 Table 6.2. Range of ROC Concentrations in Judgmental Samples.......................................................... 18

CR3 East Settling Pond Confirmatory Survey Report v

5366-SR-01-1 ACRONYMS AA alternative action Am-241 americium-241 C-14 carbon-14 CFR Code of Federal Regulations cm centimeter Cm-243 curium-243 Cm-244 curium-244 Co-60 cobalt-60 cpm counts per minute CR3 Crystal River 3 Nuclear Generating Plant CREC Crystal River Energy Complex Cs-137 cesium-137 DCGL derived concentration guideline level DEF Duke Energy Florida DQO data quality objective Eu-152 europium-152 Eu-154 europium-154 EPA U.S. Environmental Protection Agency Fe-55 iron-55 FSS final status survey GPS global positioning system H-3 tritium H0 null hypothesis HA alternative hypothesis ha hectares IL investigation level km kilometer LBGR lower bound of the gray region m2 square meter MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDC minimum detectable concentration MeV mega electron volt mrem/yr millirem per year NaI[Tl]

thallium-doped sodium iodide Nb-94 niobium-94 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 Pu-238 plutonium-238 Pu-239 plutonium-239 Pu-240 plutonium-240

CR3 East Settling Pond Confirmatory Survey Report vi 5366-SR-01-1 Pu-241 plutonium-241 Q

quantile RESL Radiological and Environmental Sciences Laboratory ROC radionuclide of concern RSS ranked set sampling SOF sum-of-fractions Sr-90 strontium-90 SU survey unit Tc-99 technetium-99 TEDE total effective dose equivalent TPU total propagated uncertainty VSP Visual Sample Plan WOCZ-01 west of contaminated zone-01

CR3 East Settling Pond Confirmatory Survey Report 1

5366-SR-01-1 CONFIRMATORY SURVEY ACTIVITIES

SUMMARY

AND RESULTS FOR THE EAST SETTLING POND AT THE CRYSTAL RIVER UNIT 3 NUCLEAR GENERATING PLANT, CRYSTAL RIVER, FLORIDA

1. INTRODUCTION The Crystal River 3 Nuclear Generating Plant (CR3) is part of the larger Crystal River Energy Complex (CREC), which is located in Crystal River, Florida, and is owned by Duke Energy Florida (DEF). CR3 was a single-unit pressurized light-water reactor with a maximum power level of 2,609 megawatt-thermal that went into commercial operation in March 1977. Final reactor shutdown occurred in September 2009. In 2013, operations had permanently ceased, and all fuel had been permanently removed from the reactor vessel (RSCS 2016). The portion of the site under jurisdiction of the 10 Code of Federal Regulations (CFR) Part 50 License is approximately (4,738 acres). In 2019 the site submitted a request for a partial site release of 1,600 ha (3,854 acres) of non-impacted land. In order to demonstrate compliance with 10 CFR 20.1402, the site is performing final status survey (FSS) activities of the impacted land areas.

The U.S. Nuclear Regulatory Commission (NRC) requested that Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities of the Settling Ponds. This report focuses on the East Settling Pond, as the West Settling Pond was not ready for confirmatory survey activities during the ORISE site visit. NRC will use the confirmatory survey data for their evaluation of the sites data relative to the project release criteria.

2. SITE DESCRIPTION CR3 is located on the Gulf of Mexico in Citrus County at 15760 West Powerline Street, Crystal River, Florida, which is approximately 12 kilometers (km) (7.5 miles) northwest of the City of Crystal River and 110 km (70 miles) north of Tampa. The current owner-controlled site is approximately 360 ha (884 acres) and includes the CR3 nuclear facility, as well as four fossil-fuel power plants, two natural draft cooling towers, coal delivery and storage areas, ash storage areas, office buildings, warehouses, barge handling docks, and a railroad following a partial site release that was approved on January 10, 2020 (RSCS 2016). Figure 2.1 provides an aerial view of the CREC.

The Settling Ponds are located west of the protected area near the south bank of the Discharge Canal and west of the large circular tanks that formerly stored oil for Units 1 and 2. The Settling

CR3 East Settling Pond Confirmatory Survey Report 2

5366-SR-01-1 Ponds are part of a survey unit (SU) west of contaminated zone-01 (WOCZ-01). Figure 2.2 shows the location of the Settling Ponds within the CREC property. Figure 2.3 shows the boundaries of SU WOCZ-01. WOCZ-01 encompass approximately 1.2 ha (12,306 square meters) and has been classified by the licensee as a Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) Class 3 SU (Crystal River 2022). Effluent from the Sewage Treatment Plant that served Units 1, 2, and 3 was discharged to these ponds. Effluent from Station Drain Tank-1 has also been discharged to the ponds on a few occasions (RSCS 2016).

Figure 2.1. Aerial View of the CREC (RSCS 2016)

CR3 East Settling Pond Confirmatory Survey Report 3

5366-SR-01-1 Figure 2.2. CR3 Preliminary Classifications of Radiological Impacts in Outlying Areas (RSCS 2016). Settling Ponds outlined in yellow.

Figure 2.3. SU WOCZ-01 Boundary outlined in red (Crystal River 2022). East Settling Pond outlined in yellow.

CR3 East Settling Pond Confirmatory Survey Report 4

5366-SR-01-1

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 2022 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, identified the planning team, and examined the project budget and schedule. The planning team, project budget, and schedule are presented in ORISE 2022 and are not discussed here. Objectives of the confirmatory survey were to provide NRC with independent radiological data to assist the NRC in evaluating the FSS results. Characterization of SU WOCZ-01 was performed in support of FSS such that the data generated would meet FSS requirements. Therefore, the problem statement was as follows:

Confirmatory survey activities are necessary to generate independent radiological data to assist the NRC with their assessment of the characterization design, implementation, and results for demonstrating compliance with the release criteria for the WOCZ-01 SU.

CR3 East Settling Pond Confirmatory Survey Report 5

5366-SR-01-1 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, and organized multiple decisions, as appropriate. This second step is done by specifying AAs that could result from a Yes response to the PSQs and combining the PSQs and AAs into decision statements. The PSQs, AAs, and decision statements are presented in Table 3.1.

Table 3.1. Independent Confirmatory Survey Decision Process Principal Study Questions Alternative Actions PSQ1: Do confirmatory survey results agree with the sites data for WOCZ-01 and are residual radioactivity cocnentrations associated with WOCZ-01 below applicable limits?

Yes:

Compile confirmatory data and report results to the NRC 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 NRC-approved decommissioning criteria, and/or that statistical sample population examination/assessment conditions were met.

No:

Compile confirmatory data and report results to the NRC for their decision making. Provide independent interpretation of confirmatory survey results, identifying any anomalous field or laboratory data and/or when statistical sample population examination/assessment conditions were not satisfied for the NRCs determination of the adequacy of the sites data.

PSQ2: Do the confirmatory results support the MARSSIM classification of the SU?

Yes:

Confirmatory results support the classification of the SU.

Compile confirmatory survey data and present results to the NRC for their decision making.

No:

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

Decision Statements Confirmatory survey results [did/did not] identify anomalous results or other conditions that would preclude the sites data from demonstrating compliance with the release criteria.

Confirmatory survey results [do/do not] support the sites MARSSIM classification of the SU.

CR3 East Settling Pond Confirmatory Survey Report 6

5366-SR-01-1 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:

• Planning documents and data for SU WOCZ-01;

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

• ORISE confirmatory survey results for gamma radiation surface scans;

• ORISE analytical results for soil samples.

3.3.1 Radionuclides of Concern and Release Guidelines The primary radionuclides of concern (ROCs) for the soil in the land areas associated with SU WOCZ-01 are beta-gamma emitters (fission and activation products) and nuclear fuel isotopes resulting from reactor operations. Site-specific DCGLs were developed 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 DCGLs are radionuclide-specific and independently correspond to a TEDE of 25 mrem/yr for each source term. ROCs and their DCGLs are presented in Table 3.2.

Table 3.2. CR3 Soil DCGLsa ROC Surface Soil DCGL (pCi/g)

ROC Surface Soil DCGL (pCi/g)

Am-241 204 Nb-94 7.77 C-14 70 Ni-59 10,900 Cm-243 76.5 Ni-63 3,990 Cm-244 262 Pu-238 167 Co-60 5.13 Pu-239 143 Cs-137 18.4 Pu-240 143 Eu-152 11.1 Pu-241 6,240 Eu-154 10.4 Sr-90 13.8 Fe-55 72,700 Tc-99 235 H-3 44,000 pCi/g = picocuries per gram aFrom Crystal River 2022

CR3 East Settling Pond Confirmatory Survey Report 7

5366-SR-01-1 Because each individual DCGL corresponds to the TEDE criterion, the sum-of-fractions (SOF) approach was used to evaluate the total dose from the SU to demonstrate compliance with the dose limit. SOF calculations were performed as follows:

=

=1 Eq. (3-1)

Where:

Cj is the concentration of ROC j DCGLj is the DCGL for ROC j 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 must be made.

SU WOCZ-01 also includes the West Settling Pond, but the scope of this confirmatory effort was limited to safely accessible surfaces within only the East Settling Pond. The study boundary of the confirmatory survey is depicted in Appendix A, Figures A.1 and A.2 (red boundary line). Portions of the sidewalls were too steep for safe access; therefore, surveys were completed in the bottom of the dry settling pond and along the safely accessible areas around the top of the settling pond. Temporal boundaries included the overall project schedule. The specific timing of on-site confirmatory activities was dependent on the decommissioning contractors schedule and notifications of when the area was ready for confirmatory activities.

3.5 DEVELOP A DECISION RULE The fifth step in the DQO process specified appropriate population parameters (e.g., mean, median), developed action levels, confirmed detection limits are less than action levels, and developed an ifthen decision rule statement. Two PSQs were introduced in Table 3.1; therefore, two decision rules arose. The first PSQ relates to whether the characterization data and IV data set are in agreement with the second confirming the appropriateness of the SU classification.

CR3 East Settling Pond Confirmatory Survey Report 8

5366-SR-01-1 3.5.1 PSQ1: Characterization and Confirmatory Data Agreement Confirmatory data/samples are not intended to demonstrate compliance with the release criterion directly, but rather demonstrate that the sites results are appropriate for the intended use. Two types of confirmatory samples were collected: judgmental and random. Judgmental samples were collected based on on-site investigations, such as gamma walkover surveys, to evaluate discrete locations exhibiting elevated radiation levels and were compared to a single-point failure criterion (i.e.,

DCGLs). Random samples were collected to potentially compare against the random/systematic characterization data set and to also compare directly to the DCGLs. The intention of the comparison of the random data sets was to identify biases - either positive or negative - and evaluate whether the bias resulted in the incorrect decision to release a SU when it did not meet the release criterion.

Generally, a positive bias between the confirmatory survey data and the sites data is more a concern than a negative bias. As such, confirmatory survey investigations described herein are designed to identify positive biases - typically 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 concentrations (MDC) - i.e., a visual comparison of the data sets is sufficient to determine if a significant bias is present that would influence the sites results. ORISE was provided the WOCZ-01 SU planning document noting the average concentration in the SU for Cs-137 was 0.089 picocuries per gram (pCi/g) with a standard deviation of 0.071 pCi/g based on previous sample data. The DCGL for Cs-137 is 18.4 pCi/g. As such, a simple random confirmatory data set was sufficient for evaluation of the characterization data. Additionally, this random data set provides NRC with an independent, unbiased estimate of the residual radiological concentrations. The decision rule addressing PSQ1 was stated as:

If unacceptable biases are not identified and/or each individual sample result is below the DCGL, then conclude that the characterization data is 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.

3.5.2 PSQ2: SU Classification The second PSQ identified in Table 3.1 sought to confirm whether the SUs were correctly classified and/or whether a particular SU should have been reclassified as a result of the characterization and

CR3 East Settling Pond Confirmatory Survey Report 9

5366-SR-01-1 was not. Reclassification relates primarily to Class 2 and Class 3 SUs, as well as non-impacted areas, as a Class 1 SU will not receive a higher classification.

The investigation levels (ILs) - for surface scans and quantitative measurements, such as soil sample analytical results - that would trigger additional evaluations were established by the site. The ILs for WOCZ-01, a Class 3 SU, are reproduced in Table 3.3. For the confirmatory survey, ORISE focused on identifying locations that would potentially exceed the soil sample ILs. Additionally, as stated in the sites WOCZ-01 characterization plan, if the average of the soil sample results exceeds the DCGL, then the SU fails to meet the release criteria. Soil sample results are further discussed in Section 6.

Table 3.3. CREC Investigation Levels a SU Classification Surface Soil Scanning IL Soil Sample IL Class 3 Reproducible indication above background using Ludlum model 44-10 and audible discrimination.

If result is >10% DCGL for Cs-137 (1.84 pCi/g) then an investigation will be performed.

aRecreated from Crystal River 2022.

The decision rule addressing PSQ2 was stated as:

If soil concentrations indicate that the SU should be reclassified to a higher classification, summarize confirmatory data for NRCs evaluation.

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 are controlled during the survey design, on-site field investigations, and during the data assessment. Each order of decision error control is discussed in detail in the subsequent subsections.

3.6.1 Hypothesis Testing The first order of control was related to the evaluation of the sites 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 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,

CR3 East Settling Pond Confirmatory Survey Report 10 5366-SR-01-1 expending budgeted resources on investigations of potentially clean areas. The confirmatory survey is the last step in the site survey and investigation process; as such, the procedures and processes used to generate the sites data have received some level of prior review both by the licensee and NRC. Therefore, the null and alternative hypotheses are as follows:

H0: The confirmatory ROC concentration population mean/median (µORISE) is less than or equal to the sites mean/median (µSITE). Mathematically, the null hypothesis is stated as:

µORISE - µSITE 0.

HA: The confirmatory ROC concentration population mean/median (µORISE) is greater than the FSS mean/median (µSITE). Mathematically, the alternative hypothesis is stated as:

µORISE - µSITE > 0.

Without going into further detail on hypothesis testing, a statistical confirmatory random data set to determine the SUs population mean/median was not generated because the entire SU was not available at the time of confirmatory activities. A simple comparison of the data sets was performed and is discussed in Section 6.

3.6.2 Field and Analytical Minimum Detectable Concentrations 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. Detector scan MDCs for the primary gamma-emitting ROCs were expected to be below the soil DCGLs. Any anomalies above background identified while performing the surveys or subsequent data assessment were thoroughly investigated.

Additionally, analytical MDCs of 10% of the each DCGL were requested.

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.

CR3 East Settling Pond Confirmatory Survey Report 11 5366-SR-01-1

4. PROCEDURES The ORISE survey team performed visual inspections, measurements, and sampling activities within the safely accessible portions of the SU during the period of October 18-19, 2022. 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 2022, ORAU 2016, ORAU 2022). 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 NAD 1983 Conus CORSS96 State Plane Florida West FIPS 0902 (meters). Measurement and sampling locations were documented on field forms and survey maps.

4.2 SURFACE SCANS Ludlum model 44-10, 5.1-centimeter (cm) by 5.1-cm (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 in all areas that were scanned. 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 flagged for further investigation and potential volumetric sampling. Accessible areas were scanned with medium-to high-density coverage. Portions of WOCZ-01 were inaccessible due to safety concerns (steep slope).

4.3 MEASUREMENT/SAMPLING LOCATIONS Samples/measurements were collected from both random and judgmentally selected locations.

Random locations were selected following a ranked set sampling (RSS) process. Judgmental locations were identified during surface scans exhibiting elevated radiation levels distinguishable

CR3 East Settling Pond Confirmatory Survey Report 12 5366-SR-01-1 from background. The total number of judgmental samples was based on the findings during survey data collection and professional judgment.

The 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). 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 combined 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. The 1-minute static NaI gamma radiation count rate data collected at randomly selected locations provided the measurable field screening method that correlated with the relative concentrations of the gamma-emitting ROCs. Professional judgment was used 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 were then 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 referred 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 was dependent on the set size and was 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 was sampled.

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

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

The number of repetitive cycles was dependent on the total number of soil samples (n) required and was a function of n and m - simply defined as n = m x r. Visual Sample Plan (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

CR3 East Settling Pond Confirmatory Survey Report 13 5366-SR-01-1 samples, the number of repetitive cycles was two (r = n/m = 6/3 = 2). The total number of assessment locations per SU was defined as m2 x r (where r = 2, in this case) = 32 x 2 = 18.

Because only the East Settling Pond in SU WOCZ-01 was ready during the confirmatory site visit, ORISE placed the 18 assessment locations in only the East Settling Pond from which 6 samples were collected.

4.4 SOIL SAMPLING Six surface soil sampling locations were randomly selected from the study area, as discussed in Section 4.3. Judgmental samples were collected from five locations identified and flagged during gamma surface scans based on elevated direct gamma radiation levels.

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 cm (0 to 6 inches) using clean hand trowels followed by a static gamma radiation measurement at the 15-cm depth. No additional depth intervals were collected as field investigations did not indicate the potential for subsurface contamination. All sampling equipment was cleaned/rinsed in the field after the collection of each sample to prevent cross-contamination.

5. SAMPLE ANALYSIS AND DATA INTERPRETATION Data collected on site were transferred to the ORISE facility for analysis and interpretation. Soil sample custody was transferred to the Radiological and Environmental Sciences Laboratory (RESL) in Idaho Falls, Idaho. Sample analyses were performed in accordance with the laboratorys applicable procedures although ORISE staff requested sample preparation be performed in accordance with ORISE procedures. Volumetric samples were homogenized, and a portion of each sample was set aside for other potential future analyses before being dried and analyzed by gamma spectrometry for gamma-emitting fission and activation products. Select samples were analyzed for the remaining ROCs listed in Table 3.2 following discussions and approval from NRC staff with two exceptions. C-14 was not reported as RESL does not currently have an approved procedure for performing C-14 analysis in solid samples. Additionally, RESL does not typically report Pu-241 when mainly statistical zeros are reported for Pu-238, and Pu-239/240 as it should not be present.

Due to their similar alpha energies curium results are reported as Cm-243/244 and plutonium

CR3 East Settling Pond Confirmatory Survey Report 14 5366-SR-01-1 results are reported as Pu-239/240. Analytical results were reported in units of picocuries per gram (pCi/g).

Gamma radiation scan results are presented as gross counts per minute (cpm). Gamma scan data results were graphed in a quantile (Q) plot 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 gross gamma response in units of cpm. 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 sites data were plotted along with the confirmatory data in strip charts to evaluate for biases. Biasespositive or negativewould be indicated by diverging data groupings.

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

6.1 SURFACE SCANS In Appendix A, Figure A.1 presents the gamma walkover data collected in WOCZ-01 East Settling Pond. The gamma responses in the SU range from approximately 3,100 cpm to 21,000 cpm. Figure 6.1 is a Q-plot of the confirmatory gamma scan data collected from the WOCZ-01 East Settling Pond. As indicated by the shape of the Q-plot, the data set is not normally distributed and indicates multiple background populations. Gamma scans identified multiple locations exhibiting elevated radiation levels relative to background, as seen in Figure A.1. Several of these areas were flagged for further investigation and/or judgmental sampling.

CR3 East Settling Pond Confirmatory Survey Report 15 5366-SR-01-1 Figure 6.1. Q Plot of Confirmatory Gamma Scan Data from WOCZ-01 East Settling Pond 6.2 RADIONUCLIDE CONCENTRATIONS IN SOIL SAMPLES Figure A.2, in Appendix A, displays the locations for the six random and five judgmental soil samples that were collected during the confirmatory survey of the WOCZ-01 East Settling Pond.

Sample coordinates and pre-and post-sample static gamma measurements are presented in Appendix B, Tables B.1 and B.2. Analytical results for the site ROC concentrations in individual soil samples are presented in Table B.3. A summary of the soil sample results is provided in Tables 6.1 and 6.2.

A simple comparison of the data sets is presented because the radionuclide concentrations were less than or approximately equal to the analytical MDCs for both the confirmatory and sites analytical data. No sample concentrations exceeded the respective DCGLs or unity for the SOF. Based on current industry guidance, such as in MARSSIM Section N.4, all reported concentrations greater

CR3 East Settling Pond Confirmatory Survey Report 16 5366-SR-01-1 than zero, even concentrations that are not considered statistically positive at the 95% confidence interval, were included in the SOF calculations. Additionally, negative values were treated as zeros.

For the curium and plutonium results, the most conservative DCGLs were used in determining the SOF. That is, for Cm-243/244 the Cm-243 DCGL of 76.5 pCi/g was used and for Pu-239/240 the Pu-239 DCGL of 143 pCi/g was used noting the DCGL for Pu-240 is also 143 pCi/g. For reasons stated in section 5, C-14 and Pu-241 are not accounted for in the SOF calculations. Only one sample (5366S0011) had a statistically positive result for plutonium, specifically Pu-238 at a very low concentration, making the additional analysis for Pu-241 unnecessary. With a DCGL of 6,240 pCi/g, Pu-241 at low concentrations would not significantly contribute to the SOF values. The sites C-14 data provided for 2 samples was reviewed and likewise, the low concentrations would not significantly contribute to the SOF values with a DCGL of 70 pCi/g. The random soil sample data set provides NRC with an unbiased estimate of the residual mean ROC concentration.

CR3 East Settling Pond Confirmatory Survey Report 17 5366-SR-01-1 Table 6.1. Descriptive Statistics for ROC Concentrations in Random Soil Samples ROC No. of Samples Analyzed Concentrations (pCi/g)

Min Max Mean Median St. Dev.

Am-241 2

-0.002 0.009 0.004 0.004 0.008 C-14a 0

Cm-243/244b 2

-0.002 0.002 0.000 0.000 0.003 Co-60 6

-0.0015 0.0022 0.0002 0.0003 0.0015 Cs-137 6

-0.002 0.0033 0.0008 0.0008 0.0022 Eu-152 6

-0.009 0.009

-0.003

-0.005 0.007 Eu-154 6

-0.01 0.019

-0.002

-0.007 0.011 Fe-55 2

-0.03 0.38 0.18 0.18 0.29 H-3 2

0 0.01 0.005 0.005 0.007 Nb-94 6

-0.003 0.0019 0.0004 0.0011 0.0018 Ni-59 2

-0.15 0.15 0.00 0.00 0.21 Ni-63 2

0.1 0.8 0.5 0.5 0.5 Pu-238 2

0.003 0.006 0.005 0.005 0.002 Pu-239/240c 2

-0.004 0.011 0.004 0.004 0.011 Pu-241d 0

Sr-90 2

0.2 0.4 0.3 0.3 0.1 Tc-99 2

-0.4 0.5 0.1 0.1 0.6 SOF 0.000 0.032 0.01 0.00 0.01 aThe selected laboratory does not currently have an approved C-14 procedure for solid samples.

bDue to similar alpha energies, Cm results are reported as Cm-243/244. The most conservative DCGL was used in SOF calculation (i.e., Cm-243).

cDue to similar alpha energies, Pu results are reported as Pu-239/240. The DCGL is the same for Pu-239 and Pu-240.

dAnalysis not performed after review of the Pu-238 and Pu-239/240 results.

CR3 East Settling Pond Confirmatory Survey Report 18 5366-SR-01-1 Table 6.2. Range of ROC Concentrations in Judgmental Samples ROC No. of Samples Analyzed Concentrations (pCi/g)

Min Max Am-241 5

-0.005 0.003 C-14a 0

Cm-243/244b 5

-0.004 0.002 Co-60 5

-0.003 0.005 Cs-137 5

-0.003 0.005 Eu-152 5

-0.026

-0.008 Eu-154 5

-0.014 0.011 Fe-55 5

-0.4 0.52 H-3 5

0 0.02 Nb-94 5

-0.002 0.002 Ni-59 5

-0.7 13.6 Ni-63 5

-1.4 0.2 Pu-238 5

-0.002 0.019 Pu-239/240c 5

-0.008

-0.002 Pu-241d 0

Sr-90 5

-0.25 0.2 Tc-99 5

-0.7 0.7 SOF 0.000 0.019 aThe selected laboratory does not currently have an approved C-14 procedure for solid samples.

bDue to similar alpha energies, Cm results are reported as Cm-243/244. The most conservative DCGL was used in SOF calculation (i.e., Cm-243).

cDue to similar alpha energies, Pu results are reported as Pu-239/240. The DCGL is the same for Pu-239 and Pu-240.

dAnalysis not performed after review of the Pu-238 and Pu-239/240 results.

Figure 6.2 provides strip charts of the ROC concentrations for the sites and confirmatory random sample data sets for the East Settling Pond. Note only the sites gamma spectroscopy results were provided to ORISE. In general, the confirmatory and sites concentrations for the listed ROCs in Figure 6.2 are similar with the sites samples having higher maximum concentrations than the confirmatory maximums. The confirmatory and sites data were compared against the Cs-137 investigation level presented in Table 3.3. No Cs-137 concentrations exceeded 10% of the DCGL for Cs-137; thus, further investigation was not necessary. Additionally, all confirmatory sample concentrations for reported ROCs were less than 10% of their respective DCGLs.

CR3 East Settling Pond Confirmatory Survey Report 19 5366-SR-01-1 Figure 6.2. Strip Charts for the Sites and Confirmatory Random Soil Sample Results

CR3 East Settling Pond Confirmatory Survey Report 20 5366-SR-01-1

7.

SUMMARY

AND CONCLUSIONS The ORISE survey team performed independent visual inspections, measurements, and sampling activities within the accessible portions of the East Settling Pond in SU WOCZ-01 during the period of October 18-19, 2022. The confirmatory activities consisted of gamma surface scans, gamma direct measurements, and soil sampling.

In total, 11 soil samples were collected: six random samples and five judgmental samples. All random and judgmental soil sample ROC concentrations were less than the respective DCGLs and all samples had a SOF value less than unity (i.e., <1). A statistical test between the sites and confirmatory data sets was not performed because the radionuclide concentrations were less than or approximately equal to the analytical MDCs. Instead, the two data sets were graphed to evaluate for biases. In general, the confirmatory and sites concentrations for the ROCs provided are similar with the sites samples having higher maximum concentrations than the confirmatory maximum concentrations. ORISE did not identify any anomalous issues from the area investigated that would preclude the sites soil data from demonstrating compliance with the release criterion. Furthermore, the confirmatory survey data supports the SU classification.

CR3 East Settling Pond Confirmatory Survey Report 21 5366-SR-01-1

8. REFERENCES Crystal River 2022. CR3 Settling Ponds Characterization Survey Plan, Draft for Comment. WOCZ CHAR. Crystal River, Florida. August.

DOE 2000. Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM), Revision 1.

DOE/EH-0624, Rev. 1. U.S. Department of Energy. Washington, D.C. August 2000.

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 2020. Minimum Detectable Concentrations with Typical Radiation Survey for Instruments for Various Contaminants and Field Conditions, Revision 1. U.S. Nuclear Regulatory Commission.

Washington, D.C. August.

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

ORAU 2020a. ORAU Health and Safety Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. October 29.

ORAU 2020b. ORAU Radiation Protection Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. November 17.

ORAU 2022. ORAU Environmental Services and Radiation Training Quality Program Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. September 8.

ORISE 2022. Project-Specific Plan for Confirmatory Survey Activities of the Settling Ponds at the Crystal River Unit 3 Nuclear Generating Plant, Crystal River, Florida. Oak Ridge Institute for Science and Education. Oak Ridge, Tennessee. October 13.

RSCS 2016. Historical Site Assessment for Crystal River 3. Technical Support Document No.16-015 Rev. 0. Radiation Safety & Control Services, Inc. Stratham, New Hampshire. June 28.

CR3 East Settling Pond Confirmatory Survey Report 5366-SR-01-1 APPENDIX A: FIGURES

CR3 East Settling Pond Confirmatory Survey Report A-1 5366-SR-01-1 Figure A.1. Gamma Walkover Data for the East Settling Pond in SU WOCZ-01

CR3 East Settling Pond Confirmatory Survey Report A-2 5366-SR-01-1 Figure A.2. Random and Judgmental Sample Locations

CR3 East Settling Pond Confirmatory Survey Report 5366-SR-01-1 APPENDIX B: DATA TABLES

CR3 East Settling Pond Confirmatory Survey Report B-1 5366-SR-01-1 Table B.1. WOCZ-01 East Settling Pond RSS Soil Sample Locations and Gamma Measurements Coordinates (m)

RSS Measurement Location Gamma Count (cpm)

Sample ID X (Easting)

Y (Northing)

Pre-Sample Post-Sample 131270 512635 RSS 1-1-1 4,500 3,200 5366S0005 131252 512589 RSS 1-1-2 7,300 131288 512617 RSS 1-1-3 9,500 131242 512645 RSS 1-2-1 5,900 6,000 5366S0003 131279 512598 RSS 1-2-2 7,500 131261 512626 RSS 1-2-3 5,300 131297 512654 RSS 1-3-1 8,600 9,400 5367S0002 131231 512583 RSS 1-3-2 7,900 131268 512611 RSS 1-3-3 4,700 131249 512639 RSS 2-1-1 8,800 131286 512592 RSS 2-1-2 10,000 131240 512620 RSS 2-1-3 4,000 2,900 5366S0006 131277 512648 RSS 2-2-1 5,800 7,600 5366S0004 131258 512601 RSS 2-2-2 12,000 131295 512629 RSS 2-2-3 5,100 131236 512657 RSS 2-3-1 8,600 131272 512586 RSS 2-3-2 13,000 14,000 5366S0001 131254 512614 RSS 2-3-3 4,400 Table B.2. WOCZ-01 East Settling Pond Judgmental Soil Sample Locations and Gamma Measurements Sample ID Coordinates (m)

Gamma Measurement (cpm)

X (Easting)

Y (Northing)

Pre-Sample Post-Sample 5366S0007 131265 512599 16,000 19,000 5366S0008 131285 512619 17,000 19,000 5366S0009 131262 512602 21,000 23,000 5366S0010 131256 512636 14,000 15,000 5366S0011 131231 512633 17,000 20,000

CR3 East Settling Pond Confirmatory Survey Report B-2 5366-SR-01-1 Table B.3. WOCZ-01 East Settling Pond Soil Sample Concentrations ROC Random Samples Judgmental Samples 5366S0001 5366S0002 5366S0003 5366S0004 5366S0005 5366S0006 5366S0007 5366S0008 5366S0009 5366S0010 5366S0011 Conc.a TPUb Conc.

TPU Conc.

TPU Conc.

TPU Conc.

TPU Conc.

TPU Conc.

TPU Conc.

TPU Conc.

TPU Conc.

TPU Conc.

TPU Am-241 (pCi/g) 0.009 0.018

-0.002 0.01

-0.005 0.016

-0.003 0.008 0.002 0.01 0.003 0.024 0.003 0.018 C-14 (pCi/g)c Cm-243/244 (pCi/g)d 0.002 0.008

-0.002 0.006

-0.002 0.006

-0.002 0.006 0.002 0.006

-0.002 0.006

-0.004 0.006 Co-60 (pCi/g) 0.0012 0.0052

-0.0015 0.0038

-0.0004 0.0034 0.0009 0.0018

-0.0013 0.003 0.0022 0.0034 0.005 0.006

-0.003 0.006 0.0012 0.0044 0.0015 0.0056 0.002 0.006 Cs-137 (pCi/g) 0.0022 0.0026

-0.002 0.006

-0.0007 0.0044 0.0033 0.0036

-0.0009 0.0036 0.0026 0.0034 0.0002 0.0006 0.005 0.006 0.0011 0.0056

-0.003 0.006 0.002 0.004 Eu-152 (pCi/g)

-0.007 0.01

-0.009 0.016

-0.008 0.03

-0.0009 0.0058

-0.003 0.01 0.009 0.01

-0.008 0.012

-0.019 0.028

-0.026 0.034

-0.009 0.01

-0.014 0.018 Eu-154 (pCi/g) 0.019 0.026

-0.008 0.008 0.004 0.01

-0.01 0.01

-0.009 0.012

-0.006 0.01 0.002 0.012

-0.012 0.018

-0.014 0.018

-0.011 0.014 0.011 0.024 Fe-55 (pCi/g) 0.38 0.36

-0.03 0.34

-0.07 0.22 0.52 0.38

-0.4 0.4 0.16 0.32 0.39 0.32 H-3 (pCi/g) 0.01 0.12 0

0.12 0.01 0.12 0

0.12 0.02 0.12 0.02 0.12 0.01 0.12 Nb-94 (pCi/g) 0.0014 0.0038

-0.003 0.006 0.00015 0.0004 0.0013 0.0038 0.0019 0.003 0.0009 0.0018 0.0012 0.0032

-0.002 0.006

-0.0008 0.0048

-0.0006 0.0048 0.002 0.006 Ni-59 (pCi/g)

-0.15 0.1 0.15 0.1 2.4 0.8 13.6 3.8 2.8 0.8 0.4 0.4

-0.7 0.8 Ni-63 (pCi/g) 0.8 0.4 0.1 0.4 0.2 1

-0.1 0.8

-0.5 0.8

-1.2 1.2

-1.4 1.2 Pu-238 (pCi/g) 0.006 0.012 0.003 0.008 0.006 0.012 0.01 0.02

-0.002 0.006 0.009 0.014 0.019 0.016 Pu-239/240 (pCi/g)e 0.011 0.014

-0.004 0.006

-0.002 0.01

-0.003 0.018

-0.002 0.008

-0.005 0.012

-0.008 0.008 Pu-241 (pCi/g)f Sr-90 (pCi/g) 0.4 0.6 0.2 0.6 0.2 0.6

-0.25 0.6 0.03 0.52

-0.09 0.6

-0.06 0.54 Tc-99 (pCi/g)

-0.4 1

0.5 1

0.7 1

0.3 1

0 1

-0.2 1

-0.7 2

SOF 0.032 0.000 0.000 0.001 0.000 0.018 0.019 0.003 0.003 0.000 0.002 aResults that are considered statistically positive are bolded.

bUncertainties are based on total propagated uncertainties at the 95% confidence level; 2-sigma uncertainty is presented.

cThe selected laboratory does not currently have an approved C-14 procedure for solid samples.

dDue to similar alpha energies, the Cm results reported as Cm-243/244. The most conservative DCGL used in SOF calculation (i.e., Cm-243) eDue to similar alpha energies, Pu results reported as Pu-239/240. Most conservative DCGL used in SOF calculation (i.e., Pu-239) noting the DCGL is the same for Pu-239 and Pu-240.

f Analysis not performed after review of the Pu-238 and Pu-239/240 results.

CR3 East Settling Pond Confirmatory Survey Report 5366-SR-01-1 APPENDIX C: MAJOR INSTRUMENTATION

CR3 East Settling Pond Confirmatory Survey Report C-1 5366-SR-01-1 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 their 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)

CR3 East Settling Pond Confirmatory Survey Report 5366-SR-01-1 APPENDIX D: SURVEY AND ANALYTICAL PROCEDURES

CR3 East Settling Pond Confirmatory Survey Report D-1 5366-SR-01-1 D.1. PROJECT HEALTH AND SAFETY The Oak Ridge Institute for 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 2016, and ORAU 2020a). Prior to on-site activities, a Work-Specific Hazard Checklist was completed for the project and discussed with field personnel. The planned activities were discussed with site personnel prior to implementation to identify hazards present. Should ORISE have identified a hazard not covered in ORAU 2016 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 2016)

• ORAU Environmental Services and Radiation Training Quality Program Manual (ORAU 2022)

The procedures contained in these manuals were developed to meet the requirements of U.S. Department of Energy (DOE) Order 414.1D and U.S. Nuclear Regulatory Commissions (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.

• Training and certification of all individuals performing procedures.

• Periodic internal and external audits.

CR3 East Settling Pond Confirmatory Survey Report D-2 5366-SR-01-1 D.3. SURVEY PROCEDURES D.3.1 SURFACE SCANS Gamma scans were performed using Ludlum model 44-10, 5.1-centimeter by 5.1-centimeter (2-inch by 2-inch) thallium-doped sodium iodide (NaI[Tl]) detectors. Scans to identify elevated radiation levels were performed by passing the detector slowly over the surface. The distance between the detectors and surface was maintained at a minimum. 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. The NaI gamma detectors were used solely as a qualitative means to identify elevated radiation levels in excess of background. However, for reference, NUREG-1507, Table 6-6, provides NaI scintillation detector scan minimum detectable concentrations (MDCs) for Common Radiological Contaminants (NRC 2020). For Cs-137, the scan MDC is 5.5 picocuries per gram (pCi/g) and 2.8 pCi/g for Co-60.

D.3.2 SOIL SAMPLING Soil samples (approximately 0.5 kilogram each from 0 to 15 centimeters) were collected by ORISE personnel using a clean hand tool to transfer soil into a new sample container. The container was labeled and security sealed in accordance with ORISE procedures. ORISE shipped samples under chain-of-custody to the Radiological and Environmental Sciences Laboratory (RESL) for analysis.

D.4. RADIOLOGICAL ANALYSIS D.4.1 GAMMA SPECTROSCOPY Following sample prep, a portion is sealed in a size appropriate container. The quantity placed in the container is chosen to reproduce the calibrated counting geometry. Net material weights are determined, and the samples are 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 are performed using computer capabilities inherent in the analyzer system. Results for the requested radionuclides of concern are provided in units of pCi/g.

CR3 East Settling Pond Confirmatory Survey Report D-3 5366-SR-01-1 D.4.2 RADIOACTIVE STRONTIUM ANALYSIS Strontium-90 (Sr-90) concentrations are quantified by total sample dissolution followed by radiochemical separation and counted on a low background liquid scintillation counter. Soil samples are dissolved by a combination of potassium hydrogen fluoride and pyrosulfate fusions. Water samples are concentrated, and strontium is separated as a sulfate with further purification. The sulfate-salts are dissolved in ethylenediaminetetraacetic acid (EDTA). The strontium is separated from residual calcium by re-precipitating strontium sulfate from the EDTA. Strontium sulfate is separated from barium by complexing the strontium sulfate in EDTA and precipitating barium sulfate at a pH of 6. The complexed strontium is precipitated as the sulfate and redissolved in EDTA. The yttrium-90 (Y-90) is allowed to in-grow, and the final sample is counted via Cherenkov counting on a liquid scintillation counter. The typical MDC for a 200-minute count time using this procedure is approximately 1 pCi/g for a 1-gram sample.

D.4.3 ALPHA SPECTROMETRY Volumetric samples are dissolved by a combination of potassium hydrogen fluoride and pyrosulfate fusions. Particle samples previously subjected to a pyrosulfate dissolution as described in D.4.2, and a measured quantity of the total dilution are treated with an additional pyrosulfate fusion in a new glass beaker. The fusion cakes are dissolved, and all alpha emitters are co-precipitated on barium sulfate. The barium sulfate is re-dissolved, and the contaminants of concern are separated from the other actinides by either oxidation/precipitations or extraction chromatography utilizing Eichrom Technologies resins, co-precipitated with neodymium fluoride, and analyzed using passivated implanted planar silicon detectors, alpha spectrometers, and multichannel analyzers. The typical MDC for samples with a quantity of 1 (total or grams) is approximately 0.02 pCi/sample or pCi/g.

D.4.4 H-3 ANALYSIS Tritium (H-3) analysis for soil samples is performed using custom distillation glassware and counted by liquid scintillation. The H-3 distillate is collected and mixed with Ultima Gold LLT (UGLLT) liquid scintillation cocktail. The typical MDC for H-3 for a 100-minute count time using this procedure is approximately 2 pCi/g.

CR3 East Settling Pond Confirmatory Survey Report D-4 5366-SR-01-1 D.4.5 NI-63 ANALYSIS Soil samples are spiked with a nickel (Ni) and cobalt carrier and digested with a mixture of nitric and hydrochloric acids or fused with potassium fluoride/pyrosulfate fusions. Unwanted elements, such as iron and cobalt, are removed via anion exchange chromatography. Nickel is then further separated from potentially interfering elements using a dimethyl glyoxime (DMG) and buffered ammonium citrate. The purified nickel is dissolved in a dilute nitric acid solution, UGLLT liquid scintillation cocktail is added, and the Ni-63 activity is determined via liquid scintillation counting.

The typical MDC for a 1-gram sample and 100-minute count time using this procedure is approximately 2 pCi/g.

D.4.6 TC-99 ANALYSIS Technetium-99 in soil is analyzed by using a sodium hydroxide fusion. The fusion cake is dissolved and passed through a TEVA disk to concentrate and purify the sample. The rinsed TEVA disk is added to a liquid scintillation vile and dissolved with UGLLT and counted on a liquid scintillation counter. The typical MDC for this procedure is approximately 0.4 pCi/g.

D.4.7 DETECTION LIMITS Each RESL analytical result is accompanied by its total propagated uncertainty expressed at one standard deviation. All results that do not pass through zero when their standard deviation is multiplied by two and then added and subtracted to the result are considered statistically positive at the 95% confidence interval. 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.