ML22279A986
ML22279A986 | |
Person / Time | |
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Site: | Zion File:ZionSolutions icon.png |
Issue date: | 09/30/2022 |
From: | Yetter R ZionSolutions |
To: | Office of Nuclear Material Safety and Safeguards |
Shared Package | |
ML22279A984 | List: |
References | |
ZS-2022-043 | |
Download: ML22279A986 (96) | |
Text
-H ZION STATION RESTORATION PROJECT FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 SEPTEMBER 2022
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Summary of Changes in this Revision: Revision 2 - Revised where necessary to address the reperformance of FSS in survey units 12201C, 12201D, 12201E, 12203A, and 12205A.
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FINAL STATUS SURVEY FINAL REPORT PHASE 4 Revision 2 Prepared By: R Yetter III Date:
LT/FSS QA/Documentation Specialist Reviewed By: R Yetter Date:
Director Radiological Site Closure Approved By: S Roberts Date:
SVP Radiological Programs 3
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 TABLE OF CONTENTS 1 Introduction ........................................................................................................................... 10 1.1 Executive Summary ....................................................................................................... 10 1.2 Phased Submittal Approach ........................................................................................... 14 2 Final Status Survey Program Overview ................................................................................ 15 2.1 Survey Planning ............................................................................................................. 15 2.2 Survey Design ................................................................................................................ 22 2.3 Survey Implementation .................................................................................................. 25 2.4 Survey Data Assessment ................................................................................................ 26 2.5 Quality Assurance and Quality Control Measures ......................................................... 26 3 Site Information .................................................................................................................... 27 3.1 Site Description .............................................................................................................. 27 3.2 Survey Unit Description ................................................................................................. 30 3.3 Summary of Historical Radiological Data ..................................................................... 44 3.4 Conditions at the Time of Final Status Survey .............................................................. 51 3.5 Identification of Potential Contaminants........................................................................ 52 3.6 Radiological Release Criteria ......................................................................................... 53 4 Final Status Survey Protocol ................................................................................................. 53 4.1 Data Quality Objectives ................................................................................................. 53 4.2 Survey Unit Designation and Classification .................................................................. 59 4.3 Background Determination ............................................................................................ 59 4.4 Final Status Survey Sample Plans .................................................................................. 59 4.5 Survey Design ................................................................................................................ 60 4.5.1 Determination of Number of Data Points ............................................................... 60 4.5.2 Sample Locations .................................................................................................... 63 4.6 Instrumentation............................................................................................................... 63 4.6.1 Detector Efficiencies ............................................................................................... 63 4.6.2 Detector Sensitivities .............................................................................................. 64 4.6.3 Instrument Maintenance and Control...................................................................... 64 4.6.4 Instrument Calibration ............................................................................................ 64 4.7 Survey Methodology ...................................................................................................... 65 4
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 4.7.1 Scan Surveys ........................................................................................................... 65 4.7.2 Soil Sampling .......................................................................................................... 65 4.8 Quality Control Surveys ................................................................................................. 66 5 Survey Findings .................................................................................................................... 66 5.1 Survey Data Conversion................................................................................................. 67 5.2 Survey Data Verification and Validation ....................................................................... 71 5.3 Anomalous Data/Elevated Scan Results and Investigation ........................................... 72 5.4 Evaluation of Number of Sample/Measurement Locations in Survey Units ................. 88 5.5 Comparison of Findings with Derived Concentration Guideline Levels ....................... 89 5.6 Description of ALARA to Achieve Final Activity Levels ............................................. 91 5.7 NRC/Independent Verification Team Findings ............................................................. 92 6 Summary ............................................................................................................................... 92 7 References ............................................................................................................................. 93 8 Appendices ............................................................................................................................ 95 5
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 LIST OF TABLES Table 1-1, Phase 4 Survey Units .................................................................................................................................. 11 Table 2-1, Base Case and Operational DCGLs for Surface Soils(1) ............................................................................. 20 Table 2-2, Base Case and Operational DCGLs for Subsurface Soils(1) ....................................................................... 20 Table 2-3, Typical Final Status Survey Unit Areas ..................................................................................................... 21 Table 2-4, Dose Significant Radionuclides and Mixture(1) .......................................................................................... 23 Figure 3-1, Zion Nuclear Power Station Owner Controlled Area ............................................................................... 28 Figure 3-2, Zion Nuclear Power Station Radiologically Restricted Area .................................................................... 29 Figure 3-3, Fuel Handling Building (FHB) and Car Shed Excavation Survey Units .................................................. 47 Figure 3-4, Demolition of Containment Domes .......................................................................................................... 48 Figure 3-5, Remediation of Indigenous Soils Following Removal of Sacrificial Soil Barrier .................................... 49 Figure 3-6, Phase 4 Open Land Areas Prepared for FSS ............................................................................................. 52 Table 4-3, Recommended Scan Coverage ................................................................................................................... 59 Table 5-1, Basic Statistical Properties for FSS of Phase 4 Open Land Survey Units .................................................. 68 Table 5-2, Mean Base Case SOF and Dose Contribution from Soil ............................................................................ 90 LIST OF FIGURES Figure 1-1, Phase 4 Survey Unit Locations ................................................................................................................. 13 Figure 2-1, Characterization/License Termination Group Organizational Chart......................................................... 17 Figure 3-1, Zion Nuclear Power Station Owner Controlled Area ............................................................................... 28 Figure 3-2, Zion Nuclear Power Station Radiologically Restricted Area .................................................................... 29 Figure 3-3, Fuel Handling Building (FHB) and Car Shed Excavation Survey Units .................................................. 47 Figure 3-4, Demolition of Containment Domes .......................................................................................................... 48 Figure 3-5, Remediation of Indigenous Soils Following Removal of Sacrificial Soil Barrier .................................... 49 Figure 3-6, Phase 4 Open Land Areas Prepared for FSS ............................................................................................. 52 6
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 LIST OF ACRONYMS AND ABBREVIATIONS ALARA As Low As Reasonably Achievable AMCG Average Member of the Critical Group ASP Alarm Set Point BcDCGL Base Case Derived Concentration Guideline Level BcSOF Base Case Sum of Fractions CCDD Clean Concrete Demolition Debris CAD Computer Aided Design CAP Corrective Action Program C/LT Characterization/License Termination ComEd Commonwealth Edison Company DCGL Derived Concentration Guideline Level DSAR Defueled Safety Analysis Report DQA Data Quality Assessment DQO Data Quality Objective DRP Discrete Radioactive Particle EMC Elevated Measurement Comparison ESCSG EnergySolutions Commercial Services Group ETD Easy-to-Detect FSS Final Status Survey FSSR Final Status Survey Final Report GPS Global Positioning System HSA Historical Site Assessment HTD Hard-to-Detect HPGe High-Purity Germanium IEMA Illinois Environmental Management Agency ISFSI Independent Spent Fuel Storage Installation LBGR Lower Bound of the Gray Region LTP License Termination Plan 7
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDC Minimum Detectable Concentration MDCR Minimum Detectable Count Rate NAD North American Datum NaI Sodium Iodide NIST National Institute of Standards and Technology NRC Nuclear Regulatory Commission ODCM Offsite Dose Calculation Manual OpDCGL Operational Derived Concentration Guideline Level OpSOF Operational Sum of Fractions ORISE Oak Ridge Institute for Science and Education PNNL Pacific Northwest National Laboratory PSDAR Post Shutdown Decommissioning Activities Report PWST Primary Water Storage Tank QA Quality Assurance QAPP Quality Assurance Project Plan QC Quality Control RAI Request for Additional Information RCA Radiologically Controlled Area RE Radiological Engineer ROC Radionuclides of Concern SFP Spent Fuel Pool SOF Sum of Fractions SSC Systems, structures and components SST Secondary Storage Tank TEDE Total Effective Dose Equivalent TSD Technical Support Document UBGR Upper Bound of the Gray Region UCL Upper Confidence Level 8
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 VCC Vertical Concrete Cask VSP Visual Sample Plan ZSRP Zion Station Restoration Project ZNPS Zion Nuclear Power Station 9
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 1 Introduction 1.1 Executive Summary The purpose of this Phase 4 Final Status Survey (FSS) Final Report is to provide a summary of the survey results and overall conclusions which demonstrate that the Zion Nuclear Power Station (ZNPS) facility, or portions of the site, meets the 25 mrem/year release criterion as established in Nuclear Regulatory Commission (NRC) Regulation 10CFR20.1402 Radiological Criteria for Unrestricted Use. This report is the final phased submittal for the Zion Station Restoration Project (ZSRP). This Phase 4 FSS Report (FSSR) was written in accordance with Section 5.11 of Chapter 5 of the ZSRP License Termination Plan (LTP)
(Reference 1).
This Phase 4 FSSR focuses on the balance of the impacted open land surface area and subsurface soils. The FSS results provided herein assess and summarize that any residual radioactivity remaining in the survey units addressed by this Phase 4 FSSR results in a Total Effective Dose Equivalent (TEDE) to an average member of the critical group (AMCG) that does not exceed 25 mrem/year and that the residual radioactivity has been reduced to levels that are As Low As Reasonably Achievable (ALARA). The release criterion is translated into site-specific Derived Concentration Guideline Levels (DCGLs) for assessment and summary.
This report documents that FSS activities were performed consistent with the guidance provided in the ZSRP LTP; NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (Reference 2); ZS-LT-01, Quality Assurance Project Plan (for Characterization and FSS) (QAPP) (Reference 3); ZS-LT-300-001-001, Final Status Survey Package Development (Reference 4); ZS-LT-300-001-003, Isolation and Control for Final Status Survey (Reference 5); ZS-LT-300-001-004, Final Status Survey Data Assessment (Reference 6); as well as various other station implementing procedures.
This Phase 4 FSSR has been written consistent with the guidance provided in NUREG-1757, Vol. 2, Consolidated Decommissioning Guidance; Characterization, Survey, and Determination of Radiological Criteria (Reference 7); MARSSIM; and the requirements specified in ZS-LT-300-001-005, Final Status Survey Data Reporting (Reference 8).
To facilitate the data management process, FSSRs incorporate Release Records from the FSS of multiple survey units. Release Records are complete and unambiguous records of the as-left radiological status of each specific survey unit. Each Release Record contains sufficient information necessary to perform an independent review and evaluation of both the survey activities, the analytical results and the final conclusion.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 This Phase 4 FSSR specifically addresses sixty-seven (67) open land area survey units that total approximately 178,182 m2 in area. Sixty (60) of the sixty-seven (67) open land survey units included in the Phase 4 report are classified as MARSSIM Class 1 survey units. Six (6) survey units are classified as Class 2, and one (1) survey unit is classified as Class 3.
Table 1-1 provides a listing of all the survey units addressed in this report, along with their classifications and size. Figure 1-1 depicts the locations of the Phase 4 survey units in relation to the ZNPS site as well as survey unit boundaries.
Table 1-1, Phase 4 Survey Units Survey Size Survey Size Name Class Name Class Unit (m2) Unit (m2)
Construction Parking 10203A East Training Area 1 1,999 10214E 1 1,989 Area Construction Parking 10203B East Training Area 1 1,977 10214F 1 1,661 Area SE Corner of Exclusion 10203C East Training Area 1 1,871 10220A 1 2,025 Area - Lakeshore SE Corner of Exclusion 10203F East Training Area 1 1,888 10220H 1 2,088 Area - Lakeshore SE Corner of Exclusion 10204A North Gate Area 1 2,231 10220I 1 2,060 Area - Lakeshore South of Protected Area -
10204B North Gate Area 1 1,549 10221A 1 1,976 Inland South of Protected Area -
10204C North Gate Area 1 1,547 10221C 1 1,959 Inland South of Protected Area -
10204D North Gate Area 1 1,545 10221D 1 1,697 Inland Station Construction North Half of Unit 2 10206A 1 2,844 12104 1 1,940 Area Containment Station Construction South Half of Unit 2 10206B 1 1,837 12105 1 1,938 Area Containment Station Construction North Half of Fuel &
10206C 1 1,833 12106 1 1,936 Area Auxiliary Buildings Station Construction South Half of Fuel &
10206D 1 1,829 12107 1 1,934 Area Auxiliary Buildings Station Construction North Half of Unit 1 10206E 1 1,825 12108 1 1,933 Area Containment South Half of Unit 1 10207A North Warehouse Area 1 2,675 12109 1 1,931 Containment Yard Between Unit 1 10207B North Warehouse Area 1 1,736 12110 1 1,740 Containment and Turbine South Yard Area 10207C North Warehouse Area 1 1,735 12111 1 1,964 Northeast of Gate House North Protected Area 10207D North Warehouse Area 1 1,733 12201A 1 1,992 Yard North Protected Area 10207E North Warehouse Area 1 1,731 12201B 1 1,995 Yard North Protected Area 10208A South Warehouse Area 1 2,460 12201C 1 1,968 Yard 11
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 1-1 (continued), Phase 4 Survey Units Survey Size Survey Size Name Class Name Class Unit (m2) Unit (m2)
North Protected Area 10208B South Warehouse Area 1 1,835 12201D 1 1,842 Yard North Protected Area 10208C South Warehouse Area 1 1,868 12201E 1 1,902 Yard Gate House and 10208D South Warehouse Area 1 1,827 12202A 1 1,998 Southwest Yard Restricted Area South of Gate House and 10209C 1 1,970 12202B 1 1,999 Gate House Southwest Yard NE Corner of Exclusion Gate House and 10212A 2 9,550 12202C 1 1,894 Area - Lakeshore Southwest Yard Gate House and 10212B VCC Construction Area 3 16,154 12202D 1 1,663 Southwest Yard NE Corner of Exclusion Gate House and 10212C 1 1,744 12202E 1 1,845 Area - Lakeshore Southwest Yard NE Corner of Exclusion Gate House and 10212D 1 1,490 12202F 1 1,858 Area - Lakeshore Southwest Yard NE Corner of Exclusion Under Service Building 10213A 2 5,730 12203A 1 1,988 Area and Southeast Yard NE Corner of Exclusion Area Under the Turbine 10213B 1 1,994 12205A 1 1,809 Area Building NE Corner of Exclusion Area Under the Turbine 10213C 1 1,934 12205B 1 1,814 Area Building Construction Parking Area Under the Turbine 10214A 2 8,542 12205C 1 1,818 Area Building Construction Parking Area Under the Turbine 10214B 2 7,372 12205D 1 1,821 Area Building Construction Parking Area Under the Turbine 10214C 2 7,579 12205E 1 1,825 Area Building Construction Parking 10214D 2 8,946 Area All FSS activities essential to data quality have been implemented and performed under approved procedures. Trained individuals, using properly calibrated instruments and laboratory equipment, that are sensitive to the Radionuclides of Concern (ROC), performed the FSS of the Phase 4 survey units in accordance with the LTP and approved procedures.
The survey data for all Phase 4 survey units demonstrate that the dose (TEDE) from residual radioactivity is less than the maximum annual dose (TEDE) which corresponds to the release criterion for license termination for unrestricted use specified in 10CFR20.1402, and support the release of these areas from the 10CFR50 license. Additionally, the ALARA requirement of 10CFR20.1402 has been satisfied.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 1-2, Phase 4 Survey Unit Locations 13
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 1.2 Phased Submittal Approach To minimize the incorporation of redundant historical assessments and other FSS program information, and to facilitate potential phased releases from the current license, FSSRs were prepared in a phased approach. A total of five (5) FSSRs, including this Phase 4 submittal, were generated and submitted to the NRC during the decommissioning project.
Release of Non-Impacted Open Lands On August 27, 2015, ZionSolutions submitted a request (ZS-2015-0134) to release a portion of the ZNPS site from the 10CFR50 licenses (DPR-39 and DPR-48) in accordance with 10CFR50.83, Release of Part of a Power Reactor Facility or Site for Unrestricted Use, and 10CFR100, Reactor Site Criteria. Specifically, a report was generated for the request that addresses the release of eleven (11) non-impacted open land areas from the 10CFR50 licenses. The report contained a summary of the final assessment performed as well as a summary of the characterization surveys performed of these non-impacted survey units.
ZionSolutions reviewed and assessed the subject property to ensure that the radiological condition of these land areas will have no adverse impact on the ability of the site, in aggregate, to meet the 10CFR20, Subpart E, Radiological Criteria for License Termination. The submitted report was not captured as a Phased Submittal with a FSSR because the survey units incorporated within the report were classified as non-impacted. As such, no statistical tests, scan measurements, static measurements, or elevated measurement comparisons were required. The release of the non-impacted areas from the license(s) was approved by the NRC on March 31, 2016.
Phase 1 Final Status Survey Report The Phase 1 FSSR was initially submitted to the NRC on November 1, 2018. The Phase 1 FSSR and the accompanying Release Records addressed the FSS of ten (10) Class 3 open land survey units at Zion. During the review of the Phase 1 FSSR, the NRC identified several quality mistakes which prompted ZionSolutions to withdraw the report until corrections were made. The required corrections were made and the Phase 1 FSSR was resubmitted to the NRC as Revision 1, minus two (2) of the original ten (10) survey units which were included in a subsequent FSSR due to the discovery of additional commodities that required removal.
On October 9, 2019, the NRC stated that the FSSR was sufficient to demonstrate that the surveys performed of seven (7) of the eight (8) Class 3 open land survey units were acceptable to support release of those survey units for unrestricted release. During the review of the revised report, the NRC Staff identified that the results from survey unit 10223 should have triggered the licensees commitment to assess subsurface residual radioactivity. By letter dated March 03, 2020, ZionSolutions submitted revision 2 of the release record for survey unit 10223 and the Phase 1 FSS Final Report. The submittal documented the results of the investigation that was completed in survey unit 10223, with regard to subsurface residual radioactivity.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Phase 2, Part 1 Final Status Survey Report The Phase 2, Part 1 FSSR, submitted to the NRC in March of 2019, contained the FSS units that encompassed the basement structures including the Unit 1 and Unit 2 Containments, the Spent Fuel Pool (SFP)/Transfer Canal, the Auxiliary Building, the Crib House/Forebay, the Waste Water Treatment Facility (WWTF) and the Turbine Building. As a result of a Condition Report regarding mistakes identified by the NRC in their review of the Phase 1 FSSR, the submittal of the Phase 2, Part 1 FSSR was withdrawn. On September 30, 2019, the revised Phase 2, Part 1 FSSR was submitted to the NRC.
Phase 2, Part 2 Final Status Survey Report The Phase 2, Part 2 FSSR and all pertinent Release Records were submitted to the NRC on November 25, 2019. The Phase 2, Part 2 FSSR contained the FSS units that encompassed buried pipe.
Phase 3 Final Status Survey Report The Phase 3 FSSR and all pertinent Release Records were submitted to the NRC on December 30, 2019. The Phase 3 FSSR addressed forty-one (41) Class 1 open land area survey units that totaled approximately 73,546 m2 in area.
2 Final Status Survey Program Overview The FSS Program consists of the methods used in planning, designing, conducting, and evaluating FSS at the ZNPS site to demonstrate that the premises are suitable for release in accordance with the criteria for decommissioning in Title 10CFR20, Subpart E. Final Status Surveys serve as the key action necessary to demonstrate that the TEDE to an AMCG from residual radioactivity does not exceed 25 mrem/year, and that all residual radioactivity at the site is reduced to levels that are ALARA.
To implement the FSS Program, ZionSolutions established the Characterization/License Termination (C/LT) Group, within the Radiation Protection division, with sufficient management and technical resources to fulfill project objectives. The C/LT Group was responsible for the safe completion of all surveys related to characterization, FSS, and final site closure. Approved site procedures and detailed technical support documents (TSD) were written to support the FSS process to ensure consistent implementation and adherence to applicable requirements. Figure 2-1 provides an organizational chart of the C/LT Group.
2.1 Survey Planning Following the cessation of commercial operation, the FSS planning phase was initiated in 1999 by the development of the Zion Station Historical Site Assessment (HSA) (Reference
- 9) and characterization process. The characterization process was iterative, and continued in 15
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 some cases up to the time of completing FSS. The HSA consisted of a review of site historical records regarding plant incidents, radiological survey documents, and routine and special reports submitted by Exelon Nuclear Generation, LLC (Exelon) to various regulatory agencies. Along with these assessments, interviews with current and past site personnel, reviews of historical site photos, and extensive area inspections were performed to meet the following objectives:
- Develop the information necessary to support FSS design, including the development of Data Quality Objectives (DQO) and survey instrument performance standards,
- Develop the initial radiological information to support decommissioning planning, including building decontamination, demolition, and waste disposal,
- Identify any unique radiological or health and safety issues associated with decommissioning,
- Identify the potential and known sources of radioactive contamination in systems, surface or subsurface soils, groundwater, and on structures,
- Divide the ZNPS site into manageable areas or units for survey and classification purposes, and
- Determine the initial classification of each survey area or unit as non-impacted or impacted. Impacted survey units are classified as Class 1, 2, or 3 as defined in MARSSIM.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 2-1, Characterization/License Termination Group Organizational Chart Senior Vice President &
General Manager Quality Assurance Manager VP -
Environmental Safety & Health Characterization/
LTP Manager Radiological Radiological Engineer Radiation Protection Engineer (LTP (Characterization/Final Instrumentation & Laboratory Lead) Status Survey Lead) Organization Support
- Radiological Instrument Supervisor
-Radiochemist
-Count Room Technician Characterization/ -Instrument Technician Radiological FSS Engineer/
Engineer Supervisors Characterization/
FSS Technicians 17
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Data Quality Objectives (DQO) are qualitative and quantitative statements derived from the DQO process. They clarify technical and quality objectives, define the appropriate type of data, and specify the tolerable levels or potential decision errors used as the basis for establishing the quality and quantity of data required to support inference and decisions. This process, described in MARSSIM and procedure ZS-LT-300-001-001, Final Status Survey Package Development, is a series of graded planning steps found to be effective in establishing criteria for data quality and guiding the development of FSS Sample Plans. The DQOs developed and implemented during the initial phase of site closure planning directed data collection efforts.
The DQO approach consists of the following seven steps:
- 1. State the Problem - This step provides a clear description of the problem, identification of planning team members (especially the decision makers), a conceptual model of the hazard to be investigated, and the estimated resources required to perform the survey.
The problem associated with FSS is to determine whether a given survey unit meets the radiological release criterion of 10CFR20.1402.
- 2. Identify the Decision - This step consists of developing a decision statement based on a principal study question (i.e., the stated problem) and determining alternative actions that may be taken based on the answer to the principle study question. Alternative actions identify the measures to resolve the problem. The decision statement combines the principal study question and alternative actions into an expression of choice among multiple actions. For the FSS, the principal study question is: Does residual radioactive contamination present in the survey unit exceed the established DCGL values? The alternative actions may include no action, investigation, resurvey, remediation, and reclassification.
- 3. Identify Inputs to the Decision - The information required depends on the type of media under consideration (e.g., soil, water, concrete) and whether existing data are sufficient or new data are needed to make the decision. If the decision can be based on existing data, then the source(s) will be documented and evaluated to ensure reasonable confidence that the data is acceptable. If new data is needed, then the type of measurement (e.g., scan, direct measurement, and/or sampling) is determined.
- 4. Define the Study Boundaries - This step includes identification of the target population of interest, the spatial and temporal features of that population, the time frame for collecting the data, practical constraints, and the scale of decision making. In FSS, the target population is the set of samples or direct measurements that constitute an area of interest. The medium of interest is specified during the planning process. The spatial boundaries include the entire area of interest, including soil depth, area dimensions, contained water bodies, and natural boundaries. Temporal boundaries include activities impacted by time-related events including weather conditions, season, operation of equipment under different environmental conditions, resource loading, and work schedule.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2
- 5. Develop a Decision Rule - This step develops the binary statement that defines a logical process for choosing among alternative actions. The decision rule is a clear statement using the If...then... format and includes action level conditions and the statistical parameter of interest.
- 6. Specify Tolerable Limits on Decision Errors - This step incorporates hypothesis testing and probabilistic sampling distributions to control the decision errors during data analysis. Hypothesis testing is a process based on the scientific method that compares a baseline condition (the null hypothesis) to an alternative condition (the alternative hypothesis). Hypothesis testing rests on the premise that the null hypothesis is true and that sufficient evidence must be provided to reject it.
- 7. Optimize the Design for Obtaining Data - The final step in the DQO process leads to the development of an adequate survey design. By using an on-site analytical laboratory, sampling and analysis processes are designed to provide near real-time data assessment during implementation of field activities and FSS. Gamma scans provide information on soil areas that have residual radioactivity greater than background and allow appropriate selection of biased sampling and measurement locations. This data will be evaluated and used to refine the scope of field activities to optimize implementation of the FSS design and ensure the DQOs are met.
As stated, the primary objective of the DQO process was to demonstrate that the level of residual radioactivity found in the soils in the land area survey units, including any areas of elevated activity, was equal to or below the site-specific DCGLs that correspond to the 25 mrem/year release criterion.
The LTP defines surface soil as in the soil layer within 0.15-m depth from the surface. The LTP defines subsurface soil as the soil layer from 0.15-m to 1-m depth of soil from the surface. Site-specific DCGLs were calculated for both the surface and subsurface soils.
Based on characterization data and historical information (LTP Chapter 5, Section 5.2.3),
there are no expectations of encountering a source term geometry that is comprised of a clean surface layer of soil over a contaminated subsurface soil layer. ZionSolutions TSD-14-011, Soil Area Factors (Reference 10) and LTP Chapter 6, Section 6.8, provide the exposure scenarios and modeling parameters that were used to calculate the site-specific DCGLs for soils (referred to as Base Case Soil DCGLs).
Each radionuclide-specific Base Case DCGL (BcDCGL) is equivalent to the level of residual radioactivity (above background levels) that could, when considered independently, result in a TEDE of 25 mrem/year to an AMCG. To ensure that the summation of dose from each source term is 25 mrem/year or less after all FSS is completed, the BcDCGLs were reduced based on an expected, or a priori, fraction of the 25 mrem/year dose limit from each source term. These reduced values were designated as Operational DCGLs (LTP Chapter 5, Section 5.2.4), and these Operational DCGLs (OpDCGL) were then used as the DCGL for the FSS design of the survey unit (calculation of surrogate DCGLs, investigations levels, etc.).
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Details of the OpDCGLs derived for each dose component and the basis for the applied a priori dose fractions are provided in ZionSolutions TSD-17-004, Operational Derived Concentration Guideline Levels for Final Status Survey (Reference 11).
Table 2-1 and Table 2-2 presents the surface and subsurface soil BcDCGL and OpDCGL for the main ROC used for the FSS of the Phase 4 open land survey units.
Table 2-2, Base Case and Operational DCGLs for Surface Soils(1)
Base Case Operational Radionuclide DCGL DCGL (pCi/g) (pCi/g)
Co-60 4.26 1.091 Cs-134 6.77 1.733 Cs-137 14.18 3.630 Ni-63 3,572.10 914.458 Sr-90 12.09 3.095 (1) Compiled from Tables 5-5 and 5-7 of LTP, Chapter 5 Table 2-3, Base Case and Operational DCGLs for Subsurface Soils(1)
Base Case Operational Radionuclide DCGL DCGL (pCi/g) (pCi/g)
Co-60 3.44 0.881 Cs-134 4.44 1.137 Cs-137 7.75 1.984 Ni-63 763.02 195.333 Sr-90 1.66 0.425 (1) Compiled from Tables 5-6 and 5-8 of LTP, Chapter 5 The development of information to support decommissioning planning and execution was accomplished through a review of known site radiological and environmental records. This information was consolidated in the HSA, TSD-14-028, Radiological Characterization Report (Reference 12), and in files containing copies of records maintained pursuant to Title 10CFR50.75(g) (1).
An initial objective of site characterization and assessment was to correlate the impact of a radiological event to physical locations on the ZNPS site and to provide a means to correlate subsequent survey data. To satisfy these objectives, the entire 331-acre site was divided into survey areas. Survey area size determination was based upon the shape of the area and the most efficient and practical size needed to bound the lateral and vertical extent of contamination identified in the area. Survey areas that have no reasonable potential for 20
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 contamination were classified as non-impacted. These areas had no radiological impact from site operations and were identified in the HSA. Survey areas with reasonable potential for contamination were classified as impacted.
Classification, as described in MARSSIM, is the process by which an area or survey unit is ranked according to its radiological characteristics and potential for residual radioactivity.
Residual radioactivity could be evenly distributed over a large area, appear as small areas of elevated activity, or a combination of both. In some cases, there may be no residual radioactivity in an area or survey unit. Therefore, the adequacy and effectiveness of the FSS process depends upon properly classified survey units to ensure that areas with the highest potential for contamination receive a higher degree of survey effort.
The impacted survey areas established by the HSA were further divided into survey units.
The suggested surface area limits provided in MARSSIM were used to establish the initial set of survey units for the LTP. A survey unit is a portion of a structure, buried pipe or open land area that is surveyed and evaluated as a single entity following FSS (note that this Phase 4 FSSR only includes land areas). Survey units were delineated to physical areas with similar operational history or similar potential for residual radioactivity to the extent practical. To the extent practical, survey units were established with relatively compact shapes. Highly irregular shapes were avoided unless the unusual shape was appropriate for the site operational history or the site topography. For identification, survey units were assigned a five-digit number that could be further modified by a letter for future divisions if needed (e.g., if the classification changed, then the corresponding survey unit size limitation also would change). Physically, survey unit boundaries were determined using commercially available mapping software with coordinates consistent with the Illinois State Plane System North American Datum (NAD) 1983 East. Table 2-3 provides an outline for classification versus area size for open land survey units consistent with MARSSIM, Table 1.
Table 2-4, Typical Final Status Survey Unit Areas Classification Area Type Suggested Area Class 1 Land Up to 2,000 m2 Class 2 Land 2,000 to 10,000 m2 Class 3 Land No Limit Prior to FSS, each survey units classification was reviewed and verified in accordance with the LTP and its implementing procedures. A classification change to increase the class could be implemented without notification to regulatory authorities. A classification change to decrease the class would be implemented only after accurate assessment and notification to regulatory authorities as detailed in the LTP and its implementing procedures. Typically, reclassification occurred after the evaluation of continuing characterization results or emergent data which indicated that a more restrictive classification was required. Final 21
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 classification was performed via the preparation of the FSS Sample Plan. The Sample Plan reconciled all outstanding characterization data to determine the appropriate and final survey unit classification for FSS.
2.2 Survey Design Final Status Surveys for the ZNPS site were designed following ZionSolutions procedures, the LTP, and MARSSIM guidance. FSS design utilized the combination of traditional scanning surveys, systematic sampling protocols, and investigative/judgmental methodologies to evaluate survey units relative to the applicable release criteria for open land sample plans.
To aid in the development of an initial suite of potential ROC for the decommissioning of ZNPS, the analytical results of characterization samples collected at the site were reviewed.
In general, the samples associated with these results were collected from within various waste/process streams and sent off site to meet the analysis criteria of 10CFR61, Subparts C and D. This initial suite of potential radionuclides was further refined by the analysis of concrete core samples taken from the concrete walls and floors of both Containment Buildings and the Auxiliary Building. This analysis determined that Co-60, Cs-134, Cs-137, Ni-63, and Sr-90 accounted for 99.5% of all dose in the contaminated concrete mixes. For activated concrete, H-3, Eu-152, and Eu-154, in addition to the five aforementioned radionuclides, accounted for 99% of the dose. Due to the assumption that all activated concrete will be removed and disposed of as waste, the final suite of ROC for all areas outside of the Containments did not include H-3, Eu-152, and Eu-154.
The results of surface and subsurface soil characterization in the impacted area surrounding ZNPS indicated that there was minimal residual radioactivity in soil. Based on the characterization survey results, ZSRP did not anticipate the presence of significant concentrations of soil contamination. In addition, based on process knowledge, minimal contamination was expected in the buried piping abandoned in place. Consequently, due to the absence of any significant source term in soil or in any buried piping, the suite of ROC and radionuclide mixture derived for the Auxiliary Building concrete was considered a reasonably conservative mixture to apply to soils for FSS planning and implementation. The final suite of potential radionuclides and the mixture to be applied to soils is provided in Table 2-4.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 2-5, Dose Significant Radionuclides and Mixture(1)
% of Total Activity Radionuclide (normalized)
Co-60 0.92 Cs-134 0.01 Cs-137 75.32 Ni-63 23.71 Sr-90 0.05 (1) Compiled from Table 5-2 of the LTP Characterization results determined that Co-60 and/or Cs-137 would be the primary gamma-emitting ROC for the majority of survey design. All the FSS results provided in this report utilized Cs-137 as the primary ROC. Cs-137 characterization data for the survey units discussed in this report were used to determine the expected variability, number of samples required, and investigation levels for FSS design.
The dose contribution from each ROC was accounted for using the Sum of Fractions (SOF) to ensure that the total dose from all ROC did not exceed the dose criterion. The SOF or unity rule was applied to the data used for the survey planning, data evaluation, and statistical tests for soil sample analyses since multiple radionuclide-specific measurements were performed, or concentrations were inferred based on known relationships. The application of the unity rule served to normalize the data to allow for an accurate comparison of the various data measurements to the release criteria. When the unity rule was applied, the DCGLW (used for the nonparametric statistical test) becomes one (1). The soil BcDCGLs (surface soil and subsurface soil) are directly analogous to the DCGLW as defined in MARSSIM. The use and application of the unity rule was performed in accordance with Section 4.3.3 of MARSSIM.
Survey design objectives included a verification of the survey instruments ability to detect the radiation(s) of interest relative to the DCGL. As standard practice employed to ensure that this objective was consistently met, radiation detection instruments used in FSS were calibrated on a yearly frequency with National Institute of Standards and Technology (NIST) traceable sources in accordance with ZionSolutions procedures. Instruments were response checked before and after each use. Minimum Detectable Count Rates (MDCR) were established and verified prior to FSS. Control and accountability of survey instruments were maintained and documented to assure quality and prevent the loss of data.
Based upon classification, the required percentage of the surface area in the survey unit was scanned (see Table 4-3) with portable gamma radiation detection instruments. Information obtained during the survey was automatically logged by the instrument for review and analysis. For Class 3 and Class 2 survey units, sample and scan coordinates were identified 23
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 using a random sample tool in Visual Sample Plan (VSP), and a survey unit-specific required scan surface area was applied around the sample point. Sample location coordinates were programmed into a Global Positioning System (GPS), then physically located and marked.
Investigational samples were collected at areas of elevated scan readings. All details and instructions were incorporated into the FSS Sample Plan for the survey unit.
Surface soil samples were collected to a depth of 0.15-meters below the topsoil surface.
Leaves, rocks, roots, and other objects were excluded as much as possible from the sample.
In Class 1 open land survey units, subsurface soil samples (soil from a depth of greater than 0.15-meters) were collected as part of the survey design. In accordance with Section 5.7.1.6.2 of the LTP, a subsurface soil sample was required at 10% of the systematic surface soil sample locations in a Class 1 survey unit with the location(s) selected at random. In addition, if during the performance of FSS, the analysis of a surface soil sample, or the results of a surface gamma scan indicated the potential presence of residual radioactivity at a concentration of 75% of the subsurface soil OpDCGL, then a biased subsurface soil sample(s) would be required to a depth of 1-meter within the area of concern as part of the investigation. This occurred in thirty-three (33) of the sixty-seven (67) open land area survey units in this Phase 4 FSSR (survey units 10204B, 10204D, 10206A, 10206B, 10206D, 10207A, 10207B, 10207C, 10207D, 10208C, 10208D, 10209C, 10212A, 10212B, 10213B, 10213C, 10214A, 10214B, 10214C, 10214D, 10214E, 10214F, 10220A, 10220I, 10221A, 10221C, 10221D, 12201C, 12201D, 12201E, 12203A, 12205A and 12205E).
Designated soil samples were sent to an off-site laboratory for Hard-to-Detect (HTD) analysis. Laboratory analysis results were summarized in Release Records and reported as actual calculated results. Sample report summaries within the Release Records included unique sample identification, analytical method, radioisotope, result, uncertainty (two standard deviations), laboratory data qualifiers, units, and required Minimum Detectable Concentration (MDC).
Another consideration of survey design was the use of surrogates. In lieu of analyzing every sample for HTD radionuclides, the development and application of Surrogate Ratio DCGLs as described in MARSSIM, Section 4.3.2 was applied to estimate the HTD radionuclide concentration in each sample and survey result. Surrogate ratios allow for expedient decision making in characterization, remediation planning, and FSS design.
A surrogate is a mathematical ratio where an Easy-to-Detect (ETD) radionuclide (i.e.,
Cs-137) concentration is related to a HTD radionuclide (i.e., Sr-90) concentration. From the analytical data, a ratio is developed and applied in the survey scheme for samples taken in the area. Details and applications of this method are provided in Section 5.2.11 of the LTP.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Some portion of the radioactivity found in the soil samples is typically attributed to fallout or background. Due to the lack of significant activity revealed during background studies, assessments and characterization, it was determined that background subtraction would not be applied during FSS.
2.3 Survey Implementation Final Status Survey implementation of the Phase 4 survey units started on January 11, 2019.
Implementation was the physical process of the FSS Sample Plan execution for a given survey unit. Each Sample Plan was assigned to a Radiological Engineer (RE) for implementation and completion in accordance with ZionSolutions procedures and the QAPP for Characterization and FSS. The tasks included in the implementation were:
- Verification and validation of personnel training as required by Training Department and Radiation Protection procedures,
- Monitoring instrument calibration as detailed in ZS-RP-108-000-000, Radiological Instrumentation Program (Reference 13) and ZS-RP-108-004-012, Calibration and Initial Set-Up of the 2350-1 (Reference 14),
- Implementation of applicable operating and health and safety procedures,
- Implementation of isolation of control of the survey unit in accordance with ZS-LT-300-001-003, Isolation and Control for Final Status Survey,
- Determination of the amount of sampling required to meet DQOs as described in ZS-LT-300-001-001, Final Status Survey Package Development,
- Determination of sample locations and creation of survey unit maps displaying the locations in accordance with ZS-LT-300-001-001,
- Proper techniques for collecting and handling FSS samples in accordance with Job Aid LT-JA-004, FSS Sample Collection (Reference 15),
- Maintaining Quality Assurance/Quality Control requirements (i.e., replicate measurements or samples) in accordance with the QAPP for Characterization and FSS.
- Sample Chain-of-Custody maintained in accordance with ZS-LT-100-001-004, Sample Media Preparation (Reference 16),
- Sample submission to approved laboratories in accordance with ZS-WM-131, Chain of Custody Protocol (Reference 17),
- Application of the DCGLs to sample results in accordance with the Data Quality Assessment (DQA) process as detailed in ZS-LT-300-001-004, Final Status Survey Data Assessment, and
- Determination of investigation methodology and corrective actions, if applicable.
The FSS implementation and completion process resulted in the generation of field data and analysis data consisting of measurements taken with handheld radiation detecting equipment, observations noted in field logs, and radionuclide specific analysis. Data were stored electronically on the ZionSolutions network.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 2.4 Survey Data Assessment Prior to proceeding with data evaluation and assessment, the assigned RE ensured consistency between the data quality and the data collection process and the applicable requirements.
The DQA process is an evaluation method used during review of FSS data to ensure the validity of FSS results and demonstrate compliance with the FSS Sample Plan objectives. A key step in the data assessment process converts all of the survey results to DCGL units. The individual measurements and sample concentrations are compared to the DCGL for evidence of small areas of elevated activity or results that are statistical outliers. When practical, graphical analyses of survey data were used to depict the spatial correlation of the measurements or samples.
For the Class 1 and Class 2 open land areas addressed in this final report, the survey data was evaluated using the Sign Test (as described in the LTP). The Sign Test is a one-sample statistical test that compares data directly to the release criteria. Combined with an effective sampling scheme, passing the Sign Test satisfies the release criteria. Selection of the Sign Test is prudent and conservative in the assumption that the radionuclides being considered are not present in background, or are at levels at a small fraction of the applicable release criteria. Furthermore, any background contribution (e.g., Cs-137 from global fallout) in the sample increases the likelihood of failing the survey unit, which is conservative. If the release criteria were exceeded or if results indicated the need for additional data points, appropriate further actions were implemented usually through the issue of an investigation as specified in ZS-LT-300-001-001, Final Status Survey Package Development, or through an addendum or redesign of the FSS Sample Plan.
2.5 Quality Assurance and Quality Control Measures Quality assurance and control measures were employed throughout the FSS process to ensure that all decisions were based on data of acceptable quality. Quality assurance and control measures were applied to ensure:
- The plan was correctly implemented,
- The DQA process was used to assess results,
- DQOs were properly defined and derived,
- All data and samples were collected by individuals with the proper training and in adherence to approved procedures and sample plans,
- All instruments were properly calibrated,
- All collected data was validated, recorded, and stored in accordance with approved procedures,
- All required documents were properly maintained, and
- Corrective actions were prescribed, implemented and tracked, as necessary.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Independent laboratories used for analysis of the samples collected during FSS maintained Quality Assurance Plans designed for their facility. ZionSolutions reviewed these plans, as required by ZS-QA-10, Quality Assurance Project Plan (Reference 18) and the QAPP for Characterization and FSS, prior to selection of a laboratory for FSS sample analysis to ensure that the standards were acceptable.
The C/LT Group has undergone surveillance by the ZionSolutions Quality Assurance (QA) department on a consistent basis throughout the project at ZNPS. The QA surveillances have scrutinized the LTP, C/LT procedures, Sample Plans, Release Records and other C/LT records. The responses to the QA surveillances were captured in the Corrective Action Program (CAP).
3 Site Information 3.1 Site Description Zion Nuclear Power Station, owned by Exelon, was located in Zion, Illinois, on the west shore of Lake Michigan. The site is approximately 40 miles north of Chicago, Illinois, and 42 miles south of Milwaukee, Wisconsin.
The owner-controlled site (see Figure 3-1) consisted of approximately 331 acres, and within the owner-controlled area was an approximate 87-acre, fence-enclosed nuclear facility (see Figure 3-2). The center of the community of Zion is approximately 1.6 miles from the plant location on the site. There were no schools or hospitals within one mile of the site, and no residences within 2,000 feet of any ZNPS structures.
Westinghouse Electric Corporation, Sargent and Lundy Engineers, and the Commonwealth Edison Company (ComEd) jointly participated in the design and construction of ZNPS. The plant was comprised of two (2) pressurized water reactors with supporting facilities. The primary coolant system for each unit employed a four-loop pressurized water reactor nuclear steam supply system housed in a steel-lined, reinforced concrete containment structure. Each unit employed a pressurized water reactor nuclear steam supply system furnished by Westinghouse Electric Corporation, designed for a power output of 3,250 MWt. The equivalent warranted gross and approximate net electrical outputs of the plant were 1085 MWe and 1050 MWe, for Unit 1 and Unit 2, respectively.
ZNPS was previously operated by Commonwealth Edison until it was permanently shut down on February 13, 1998. On March 9, 1998, ComEd certified to the NRC that all fuel assemblies had been permanently removed from both reactors and placed in the Spent Fuel Pool. The NRC acknowledged the certification of permanent cessation of power operation and permanent removal of fuel from the reactor vessels in a letter dated May 4, 1998. In 2000, the license was transferred from ComEd to Exelon. In 2008, the license was transferred to ZionSolutions to coordinate and execute the decommissioning of the site.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 3-1, Zion Nuclear Power Station Owner Controlled Area 28
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 4-2, Zion Nuclear Power Station Radiologically Restricted Area 29
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 The Post Shutdown Decommissioning Activities Report (PSDAR) (Reference 19) was submitted, in accordance with 10CFR50.82(a), in February 2000 and accepted by the NRC.
An amended PSDAR was submitted in March 2008 to accommodate the transfer of the 10CFR50 licenses to ZionSolutions and to revise cost estimates and the decommissioning schedule. The Defueled Safety Analysis Report (DSAR) (Reference 20) was updated in October 2016. An evaluation of the systems, structures, and components (SSCs) was performed to determine the function these systems would perform in a defueled condition.
With the relocation of the spent fuel to the Independent Spent Fuel Storage Installation (ISFSI), the license basis for the majority of the SSCs was changed, and only minimal SSCs were needed to support the ongoing active decommissioning. The remaining SSCs needed to support active decommissioning had controls established in the QAPP and the Offsite Dose Calculation Manual (ODCM) (Reference 21).
Site characterization commenced on November 2, 2011. At the time when characterization commenced, the site-specific ZionSolutions characterization plans and procedures were still under development. Consequently, due to schedule restraints, ZionSolutions contracted the EnergySolutions Commercial Services Group (ESCSG) to perform characterization of the ISFSI location, the Vertical Concrete Cask (VCC) Construction Area, and the pathway for the new rail track. The results of these surveys were validated and integrated into the subsequent site-specific characterization program, which was approved in February 2012.
Initial scheduled site characterization efforts concluded on November 11, 2013.
3.2 Survey Unit Description The following information is a description of each survey unit addressed in this report at the time of FSS from January 2019 until August 2022. During this period, sixty-seven (67) open land area survey units that comprise an area of approximately 178,182 m 2 (44 acres), were evaluated in accordance with the FSS process specified in the LTP.
Survey Unit 10203A Survey unit 10203A, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey units 10204D and 10206E, the south by survey unit 12201A, on the east by survey units 10203B, 10203C, and 10203F, and the north by survey unit 10214D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam.
Survey Unit 10203B Survey unit 10203B, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10203A, the east by survey units 10203C and 10203D, the north by survey unit 10203C, and the south by survey unit 10203F.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10203C Survey unit 10203C, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10203A, the northeast by survey unit 10213C, the northwest by survey unit 10214D, the east by survey unit 10203D, and the south by survey unit 10203B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10203F Survey unit 10203F, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10203A, the south by survey units 12201A and 12201B, and the north by survey units 10203B and 10203D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam.
Survey Unit 10204A Survey unit 10204A, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10205, the south by survey units 10206A and 10206B, on the east by survey unit 10204B, and the north by survey unit 10214C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .
Survey Unit 10204B Survey unit 10204B, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10204A, the south by 10206B and 10206C, on the east by 10204C, and the north by 10214C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .
Survey Unit 10204C Survey unit 10204C, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10204B, the south by survey units 10206C and 10206D, on the east by survey unit 10204D, and the north by survey unit 10214D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10204D Survey unit 10204D, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10204C, the south by survey units 10206D and 10206E, on the east by survey unit 10203A, and the north by survey unit 10214D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .
Survey Unit 10206A Survey unit 10206A, the Station Construction Area, is a Class 1 open land survey unit.
The survey unit is bounded on the west by survey unit 10205, the south by survey unit 10207A, on the east by survey unit 10206B, and the north by survey unit 10204A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .
Survey Unit 10206B Survey unit 10206B, the Station Construction Area, is a Class 1 open land survey unit.
The survey unit is bounded on the west by survey unit 10206A, the south by survey unit 10207B, on the east by survey unit 10206C, and the north by survey units 10204A and 10204B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .
Survey Unit 10206C Survey unit 10206C, the Station Construction Area, is a Class 1 open land survey unit.
The survey unit is bounded on the west by survey unit 10206B, the south by survey unit 10207C, on the east by survey unit 10206D, and the north by survey units 10204B and 10204C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .
Survey Unit 10206D Survey unit 10206D, the Station Construction Area, is a Class 1 open land survey unit.
The survey unit is bounded on the west by survey unit 10206C, the east by survey unit 10206E, the north by survey units 10204C and 10204D; and the south by survey unit 10207D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of loam .
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10206E Survey unit 10206E, Station Construction Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10206D, the northeast by survey unit 10203A, the southeast by survey unit 12202A, the north by survey unit 10204D, and the south by survey unit 10207E.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10207A Survey unit 10207A, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10205, the south by survey unit 10208A, the east by survey unit 10207B, and the north by survey unit 10206A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the survey unit from the north to south.
Survey Unit 10207B Survey unit 10207B, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207A, the south by survey units 10208A and 10208B, the east by survey unit 10207C, and the north by survey unit 10206B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10207C Survey unit 10207C, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207B, the south by survey units 10208B and 10208C, the east by survey unit 10207D, and the north by survey unit 10206C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10207D Survey unit 10207D, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207C, the south by survey unit 10208C, the east by survey unit 10207E, and the north by survey unit 10206D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10207E Survey unit 10207E, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207D, the south by survey unit 10208D, the east by survey units 12202B and 12202C, and the north by survey unit 10206E.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10208A Survey unit 10208A, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10205, the east by survey unit 10208B, the north by survey units 10207A and 10207B; and the south by survey unit 10218A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the survey unit from the north to south.
Survey Unit 10208B Survey unit 10208B, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10208A, the east by survey unit 10208C, the north by survey units 10207B and 10207C; and the south by survey unit 10218A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10208C Survey unit 10208C, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10208B, the east by survey unit 10208D, the north by survey units 10207C and 10207D; and the south by survey units 10218A and 10221A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10208D Survey unit 10208D, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10208C, the east by survey units 12202E and 10209A; the north by survey unit 10207E, and the south by survey unit 10221A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10209C Survey unit 10209C, Restricted Area South of Gate House, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10209B, the east by 10209D, the north by survey units 12202E and 12202F, and the south by survey units 10221B and 10221C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10212A Survey unit 10212A, NE Corner of Exclusion Area - Lakeshore, is a Class 2 open land survey unit. It is bounded on the west by survey units 10213A and 10213B; the east by survey unit 10222, the north by survey unit 10212B and the south by survey units 10212C and 10201A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10212B Survey unit 10212B, VCC Construction Area, is a Class 3 open land survey unit. It is bounded on the west by survey unit 10214E, the east by survey unit 10222, the north by a non-impacted area and the south by survey units 10212A, 10213A and 10214E.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10212C Survey unit 10212C, NE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10213C, the east by survey unit 10212A, the north by survey unit 10212A and the south by survey unit 10212D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10212D Survey unit 10212D, NE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10213C, the east by survey unit 10212A, the north by survey unit 10212C and the south by survey units 10201A, 10202A and 10203E.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A drainage ditch, which is designated a wetland, runs west to east through the survey unit.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10213A Survey unit 10213A, NE Corner of Exclusion Area, is a Class 2 open land survey unit. It is bounded on the west by survey units 10214D and 10214E; the east by survey unit 10212A, the north by survey unit 10212B and the south by survey unit 10213B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10213B Survey unit 10213B, NE Corner of Exclusion Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214D, the east by survey unit 10212A, the north by survey unit 10213A and the south by survey unit 10213C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam and the area is located within a floodplain.
Survey Unit 10213C Survey unit 10213C, NE Corner of Exclusion Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214D, the east by survey units 10212C and 10212D; the north by survey unit 10213B and the south by survey units 10203C through 10203E.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam and the area is located within a floodplain.
Survey Unit 10214A Survey unit 10214A, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by a non-impacted area, the east by survey unit 10214B, the north by a non-impacted area and the south by survey unit 10205.
The topography of the survey unit is mainly flat with some small dips and depressions. Since this area was used for parking, the top surface is a mixture of gravel and soil. A paved road runs east to west in the northern part of the survey unit.
Survey Unit 10214B Survey unit 10214B, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by survey unit 10214A, the east by survey units 10214C and 10214F; the north by a non-impacted area and the south by survey unit 10205.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10214C Survey unit 10214C, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by survey units 10214B and 10214F; the east by survey unit 10214D, the north by a non-impacted area and the south by survey units 10205, 10204A, and 10204B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. Rail tracks run through the center of the survey unit in a north-south direction.
Survey Unit 10214D Survey unit 10214D, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by survey unit 10214C, the east by survey units 10213A, 10213B, 10213C and 10214E; the north by a non-impacted area and the south by survey units 10203A, 10203C, 10204B, 10204C and 10204D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 10214E Survey unit 10214E, Construction Parking Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214D, the east by survey units 10212B and 10213A; the north by a non-impacted area and the south by survey unit 10214D.
The topography of the survey unit is mainly flat with some small dips and depressions. The top surface is a mixture of gravel and soil.
Survey Unit 10214F Survey unit 10214F, Construction Parking Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214B, the east by survey unit 10124C, the north by survey units 10214B and 10214C; and the south by survey units 10214B and 10214C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly gravel as it was used as a parking area. A rail spur, with a ballast made up of gravel, runs through the eastern half of the survey unit.
Survey Unit 10220A Survey unit 10220A, the SE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey units 10220E, 10220F, and 10220G, the south by survey unit 10220C, the east by survey unit 10220H, and the north by survey units 10221A and 10221B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10220H Survey unit 10220H, SE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10220A, the south by survey unit 10220C, the east by survey unit 10220I, and the north by survey units 10221B and 10221C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A Wetland area runs along the southeast boundary of the survey unit.
Survey Unit 10220I Survey unit 10220I, the SE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10220H, the south by survey unit 10220C, the east by survey unit 10220J, and the north by survey units 10221C, 10221D and 10221H.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. There is a wetland area on the west side of the survey unit.
Survey Unit 10221A Survey unit 10221A, South of Protected Area - Inland is a Class 1 open land survey unit.
It is bounded on the west by survey unit 10218 (ISFSI), the east by survey unit 10221B, the north by survey units 10208C, 10208D, 10209A and 10209B; and the south by survey units 10220A and 10220G.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the survey unit from the southeast corner to the northwest corner.
Survey Unit 10221C Survey unit 10221C, South of Protected Area - Inland, is a Class 1 open land survey unit.
It is bounded on the west by survey unit 10221B, the east by survey unit 10221D, the north by survey units 10209C through 10209E; and the south by survey units 10220H and 10220I.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the southern half of the survey unit.
Survey Unit 10221D Survey unit 10221D, South of Protected Area - Inland, is a Class 1 open land survey unit.
It is bounded on the west by survey unit 10221C, the south by survey unit 10220I, the east by survey units 10221E through 10221H; and the north by survey units 10209E, 10210A and 10210B.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the southern part of the survey unit and a drainage ditch runs north to south through the survey unit.
Survey Unit 12104 Survey unit 12104, described as the North Half of Unit 2 Containment, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202A, the south by survey unit 12105, the east by survey unit 12205A, and the north by survey units 12201A through 12201C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12105 Survey unit 12105, South Half of Unit 2 Containment, is a Class 1 open land survey unit.
It is bounded on the west by survey unit 12202A, the south by survey unit 12106, the east by survey units 12205A and 12205B; and the north by survey unit 12104.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12106 Survey unit 12106, North Half of Fuel & Auxiliary Buildings, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202A, the south by survey unit 12107, the east by survey units 12205B and 12205C; and the north by survey unit 12105.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12107 Survey unit 12107, the South Half of Fuel & Auxiliary Buildings, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202B, the south by survey unit 12108, the east by survey unit 12205C, and the north by survey unit 12106.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12108 Survey unit 12108, the North Half of Unit 1 Containment, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202B, the east by survey units 12205C and 12205D; the north by survey unit 12107 and the south by survey unit 12109.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 12109 Survey unit 12109, the South Half of Unit 1 Containment, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202B, the south by survey unit 12110, the east by survey units 12205D and 12205E, and the north by survey unit 12108.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12110 Survey unit 12110, the Yard Between Unit 1 Containment and Turbine, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202C, the east by survey unit 12205E, the north by survey unit 12109 and the south by survey units 12202D and 12111.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12111 Survey unit 12111, the South Yard Area Northeast of Gate House, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202D, the south by survey unit 12202F, the east by survey units 12203A and 12205E, and the north by survey unit 12110.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12201A Survey unit 12201A, the North Protected Area Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10206E, the south by survey units 12104 and 12202A, the east by survey unit 12201B, and the north by survey units 10203A and 10203F.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12201B Survey unit 12201B, the North Protected Area Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12201A, the south by survey unit 12104, the east by survey unit 12201C, and the north by survey units 10203D, 10203E, and 10203F.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 12201C Survey unit 12201C, the North Protected Area Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12201B, the south by survey units 12104 and 12205A, the east by survey unit 12201D, and the north by survey units 10203E and 10202D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12201D Survey unit 12201D, the North Protected Area Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12201C, the south by survey unit 12205A, the east by survey unit 12201E, and the north by survey unit 10202D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 12201E Survey unit 12201E, the North Protected Area Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12201D, the south by survey unit 12205A, the east by survey units 12101, 12102, and 12103, and the north by survey unit 10202D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
Survey Unit 12202A Survey unit 12202A, the Gate House and Southwest Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10206E, the south by survey unit 12202B, the east by survey units 12104 through 12106, and the north by survey unit 12201A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12202B Survey unit 12202B, the Gate House and Southwest Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10206E and 10207E, the south by survey unit 12202C, the east by survey units 12107, 12108, and 12109, and the north by survey unit 12202A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 12202C Survey unit 12202C, the Gate House and Southwest Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207E, the south by survey unit 12202E, the east by survey units 12202D and 12110, and the north by survey unit 12202B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12202D Survey unit 12202D, the Gate House and Southwest Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202C, the south by survey units 12202E and 12202F, the east by survey units 12110 and 12111, and the north by survey unit 12110.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12202E Survey unit 12202E, the Gate House and Southwest Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10208D, the south by survey units 10209A, 10209B, and 10209C, the east by survey unit 12202F, and the north by survey units 12202C and 12202D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12202F Survey unit 12202F, the Gate House and Southwest Yard, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202E, the south by survey units 10209C, 10209D, 10209E, and 10210A, the east by survey unit 12203A, and the north by survey units 12202D and 12111.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12203A Survey unit 12203A, Under Service Building and Southeast Yard is a Class 1 open land survey unit. It is bounded on the west by survey units 12111 and 12202F, the south by survey units 10210A and 10210B, the east by survey unit 12203B, and the north by survey unit 12205E.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 12205A Survey unit 12205A, the Area Under the Turbine Building, is a Class 1 open land survey unit. It is bounded on the west by survey units 12104 and 12105, the south by survey unit 12205B, the east by survey units 12103 and 12204A, and the north by survey units 12201C, 12201D, and 12201E.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12205B Survey unit 12205B, the Area Under the Turbine Building, is a Class 1 open land survey unit. It is bounded on the west by survey units 12105 and 12106, the south by survey unit 12205C, the east by survey units 12204A and 12204B, and the north by survey unit 12205A.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12205C Survey unit 12205C, the Area Under the Turbine Building, is a Class 1 open land survey unit. It is bounded on the west by survey units 12106, 12107, and 12108, the south by survey unit 12205D, the east by survey units 12204B and 12204C, and the north by survey unit 12205B.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12205D Survey unit 12205D, the Area Under the Turbine Building, is a Class 1 open land survey unit. It is bounded on the west by survey units 12108 and 12109, the south by survey unit 12205E, the east by survey units 12204C and 12113, and the north by survey unit 12205C.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
Survey Unit 12205E Survey unit 12205E, the Area Under the Turbine Building, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12109, 12110, and 12111, the south by survey units 12203A and 12203B, the east by survey unit 12113, and the north by survey unit 12205D.
The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly sand.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 3.3 Summary of Historical Radiological Data The historical site radiological data for this Phase 4 FSSR at ZNPS incorporated the results of the HSA issued in 1999 and supplemented in 2006 and included the initial characterization surveys completed in 2013.
Historical Site Assessment The HSA was a detailed investigation to collect existing information (from the start of ZNPS activities related to radioactive materials or other contaminants) for the site and its surroundings. The HSA focused on historical events and routine operational processes that resulted in contamination of plant systems, onsite buildings, surface and subsurface soils within the Radiologically Controlled Area (RCA). It also addressed support structures, open land areas and subsurface soils outside of the RCA but within the owner-controlled area.
The information compiled by the HSA was used to establish initial survey units and their MARSSIM classifications. This information was used as input into the development of site-specific DCGLs, remediation plans and the design of the FSS. The scope of the HSA included potential contamination from radioactive materials, hazardous materials, and other regulated materials.
The objectives of the HSA were to:
- Identify potential, likely, or known sources of radioactive and chemical contaminants based on existing or derived information,
- Distinguish portions of the site that may need further action from those that pose little or no threat to human health,
- Provide an assessment of the likelihood of contaminant migration,
- Provide information useful to subsequent continuing characterization surveys,
- Provide an initial classification of areas and structures as non-impacted or impacted,
- Provide a graded initial classification for impacted soils and structures in accordance with MARSSIM guidance, and
- Delineate initial survey unit boundaries based upon the initial classification.
The survey units established by the HSA were used as initial survey units for characterization. Prior to characterization, survey unit sizes were adjusted in accordance with the guidance provided in MARSSIM Section 4.6 for the suggested physical area sizes for survey units for FSS.
Of the sixty-seven (67) open land area survey units in this Phase 4 FSSR, only eight (8) survey units (survey units 12104, 12105, 12106, 12107, 12108, 12109, 12110 and 12111) were given an initial classification as Class 1, and seventeen (17) survey units (survey units 12201A, 12201B, 12201C, 12201D, 12201E, 12202A, 12202B, 12202C, 12202D, 12202E, 12202F, 12203A, 12205A, 12205B, 12205C, 12205D and 12205E) were given an initial classification as Class 2 by the HSA. Based on process knowledge and historical surveys to 44
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 date, the remaining forty-two (42) survey units were given an initial classification of Class
- 3. During building demolition in the Spring of 2017, discrete particles of radioactive material were identified during the performance of operational surveys and Radiological Assessments (RA) in and around the Class 2 and Class 3 survey units. As a conservative measure starting in July of 2016, the classification of a majority of the open land survey units located within the 87-acre, fence-enclosed area was increased to Class 1. This action included all survey units addressed in this report that were initially classified as Class 2 or Class 3 with the exception of survey units 10212A, 10213A, 10214A, 10214B, 10214C and 10214D, which had a final classification of Class 2 and survey unit 10212B, which retained its original classification as Class 3.
Characterization Surveys Site characterization of the ZNPS was performed in accordance with ZS-LT-02, Characterization Survey Plan (Reference 22). It was developed to provide guidance and direction to the personnel responsible for implementing and executing characterization survey activities. The Characterization Survey Plan worked in conjunction with implementing procedures and survey unit specific survey instructions (sample plans) that were developed to safely and effectively acquire the requisite characterization data.
Characterization data acquired through the execution of the Characterization Survey Plan was used to meet three primary objectives:
- Provide radiological inputs necessary for the design of FSS,
- Develop the required inputs for the LTP,
- Support the evaluation of remediation alternatives and technologies and estimate waste volumes.
The final output of the initial site characterization was TSD-14-028, Radiological Characterization Report. The report concluded that based on the results of the characterization surveys, it was expected that residual plant-derived radioactivity was present in the sixty-seven (67) survey units addressed by this report.
FSS of Excavated Areas In the Spring of 2018, an area was excavated to expose the remaining foundation of the Fuel Handling Building (FHB) and Car Shed (see Figure 3-3). This excavation included the west half of survey units 12105, 12106, and 12107. An FSS sample plan was written to perform an FSS on the exposed subsurface soil within the excavation prior to backfill to grade. When the FSS was performed, these survey units were designated as survey units 12105K, 12106K, and 12107K. This survey area within the excavation was assigned a MARSSIM classification of 1. A survey plan was designed based upon use of the Sign Test as the nonparametric statistical test for compliance. Both the Type I () and Type II () decision error rates were set at 0.05. Scanning was performed on 100% of the total exposed 45
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 excavation surface area. No areas of elevated activity were detected during the scans.
Seventeen (17) systematic soil samples were acquired from within each survey unit. When compared to the OpDCGL for subsurface soils, the maximum observed OpSOF was 0.453 for a subsurface soil sample taken within the excavation, with survey unit 12107K exhibiting the largest mean OpSOF of 0.155. This area was subsequently backfilled with clean fill prior to the demolition of the Containment Buildings. The results of the FSS performed on survey units 12105K, 12106K, and 12107K are included as Addendums to Release Records 12105, 12106, and 12107, respectively.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 5-3, Fuel Handling Building (FHB) and Car Shed Excavation Survey Units 12106K 12107K 12105K 47
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Continuing Characterization Chapter 5, Section 5.3.4.4 of the LTP states that the subsurface soils in the keyways between the Containment Buildings and the Turbine Building will be assessed for radiological contamination of subsurface soils once subsurface utilities and subsurface access-interfering structures (e.g., Waste Annex Building) had been removed. This applied to the survey unit 12109 as well as the north boundary of survey unit 12110.
During the course of the decommissioning and the remediation of the indigenous soils following the removal of the sacrificial layer, the soils in question were completely removed and disposed of as contaminated waste. The tops of the underlying structures were exposed, and post-remediation scans and samples taken from the excavation prior to backfill did not indicate the presence of the ROC at concentrations exceeding the OpDCGLs. No further action was taken.
In August of 2018, ZSRP completed the demolition and backfill of the Auxiliary Building basement and Spent Fuel Pool (SFP). The next buildings that were slated for demolition were the Unit 1 and Unit 2 Containment domes. It was the intention of ZSRP at the time to designate the exterior concrete of the Unit 1 and Unit 2 Containment domes as Clean Concrete Demolition Debris (CCDD) and to use the CCDD as fill material in basements. However, for the concrete to be considered for use as CCDD, it was important to maintain its unrestricted release pedigree. The 588-foot grade surface soils surrounding the two containments were identified as contaminated. While it was necessary to remediate the soils surrounding the Containments, the timeframe required was prohibitive at the time. Therefore, in lieu of remediating the exposed soil, a sacrificial layer of clean soil from off-site was placed over the contaminated indigenous surface soil with up to 1 1/2 feet of clean fill. Once the sacrificial layer was in place, the Containment dome structures were demolished without having to wait for the remediation to be completed (see Figures 3-4).
Figure 6-4, Demolition of Containment Domes 48
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 From August 2018 through December 2018, both Unit 1 and Unit 2 Containments were demolished and the resultant CCDD was removed from the area. After removal of the CCDD, the sacrificial soil was removed and the exposed 588-foot indigenous soils were scanned. The survey was performed under an RA, which required 100% scan of the soils exposed by the removal of the sacrificial layer with an alarm set-point set at the MDCR of the instrument plus background. Any indication of elevated activity greater than the MDCR would then prompt investigation and remediation as necessary.
From February 26, 2019, through June 18, 2019, scanning and remediation commenced south of Unit 1 and progressed to the north and west of the Containment footprints (see Figure 3-5). Large areas of elevated activity were identified by scan and verified by soil sample analysis and subsequently marked. All soil identified as exceeding the OpDCGLs for subsurface soil was excavated and disposed of as radioactive waste. Following excavation, post-remediation surveys were performed by scan and media sampling. The analysis of all post-remediation soil samples showed an OpSOF less than one (1) when sample results were directly compared against the OpDCGLs for subsurface soils. However, all excavations remained open to allow the Oak Ridge Institute for Science and Education (ORISE) to perform confirmatory surveys of the exposed remediated soil.
Figure 7-5, Remediation of Indigenous Soils Following Removal of Sacrificial Soil Barrier 49
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 ORISE performed confirmatory surveys of the exposed subsurface soils surrounding the Containments in August of 2019. Three (3) small particles of radioactive material were identified by the ORISE survey. The particles were captured and removed. Shortly thereafter, clean fill was acquired from an off-site source and used to increase the grade of all survey units surrounding any end-state basement to the 591-foot elevation. In accordance with LTP Chapter 6, Section 6.4.1, the end-state basements must be covered by at least three feet of clean soil and physically altered to a condition which would not realistically allow the remaining structures, if excavated, to be occupied.
Section 5.3.4.4 of LTP Chapter 5 states that attempts shall be made to acquire subsurface soil samples from beneath each Containment basement foundation and the Auxiliary Building basement floor slab. The objective was to assess the radiological contamination of subsurface soils adjacent to and below these basement slabs. Section 5.3.4.4 of LTP Chapter 5 also states that attempts shall be made to acquire soil samples from beneath each basement floor slab and around each foundation from grade to the floor slab depth or refusal, whichever was less.
Many attempts were made to acquire these samples following the demolition of all above-grade structures. As part of this effort, one (1) subsurface soil sample was taken in survey unit 12109 along the west side of the Auxiliary Building to a depth of 52 feet below grade, where refusal was met. Several attempts were made to acquire samples at a deeper depth and below the basement slab in survey unit 12109. However, with the exception of sample acquired under the Auxiliary Building, the mud-mat placed around the Containment basement exterior during construction obstructed the GeoProbe from acquiring samples at a deeper depth. For the sample acquired in survey unit 12109, the probe was able to punch through the mud-mat and acquire a sample at a sub-basement slab depth. Twelve (12) additional samples were taken adjacent to the foundations of both Unit 1 and Unit 2 Containment buildings and the Auxiliary Building to a depth of 32 feet to 48 feet. All of the deep subsurface soil samples were analyzed by the on-site gamma spectroscopy system. No ROCs were positively detected in any of these samples except for one sample taken along the foundation of Unit 2 Containment where Cs-137 was positively detected at a concentration of 0.095 pCi/g which is below the action level that would require an investigation.
Reperformance of FSS in 2021 and 2022 After the initial FSS in survey unit 12203A, Clean Concrete Demolition Debris (CCDD) was stored in the survey unit prior to the debris final disposal. The FSS was reperformed to address concerns regarding the placement and removal of CCDD into 12203A after the initial FSS was performed.
Following the completion of FSS in survey units 12201C and 12201D, concrete foundation structures were found in the survey units that did not meet the requirement that all remaining 50
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 structures be below 588 grade. Excavations were performed to remove this concrete.
Because the geologic features of the survey units significantly changed during the excavation, the FSS was reperformed following the completion of this work.
Following the completion of FSS in survey units 12205A and 12201E, clean fill was imported from off-site and placed on portions of the survey units to ensure discovered buried items were three feet below grade. Because the geologic features of the survey units significantly changed due to the fill, the FSSs were reperformed following the completion of this work.
3.4 Conditions at the Time of Final Status Survey The land areas discussed in this report were open land areas. All above ground structures and commodities were removed and disposed of during decommissioning (see Figure 3-6).
Portions of the open land areas specified were excavated to remove buried pipe and commodities. Excavations created to remove sub-grade commodities were assessed against the OpDCGLs for subsurface soil prior to backfill in accordance with LTP Chapter 5, Section 5.7.1.6. All subsurface soil that was identified as exceeding the subsurface soil OpDCGLs was excavated and removed as waste. Excavations were backfilled using overburden that was verified to be less than the subsurface soil OpDCGLs or with clean fill brought in from non-radiological off-site sources. Open land survey units were then smoothed and brought to grade using heavy earth-moving machinery. Transit roads consisting of gravel and hard packed dirt were maintained for vehicular traffic.
Prior to FSS, areas ready for survey were isolated and controlled under ZS-LT-300-001-003, Isolation and Control for Final Status Survey. This included posting of the area as well as notifications to site personnel. Permission was obtained from C/LT staff to enter and work in these areas. Posting of the boundaries controlled public access, and a routine surveillance program monitored for any inadvertent public access with procedurally defined recovery and reporting protocols in the event of any impact to the final status of these survey units.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 8-6, Phase 4 Open Land Areas Prepared for FSS 3.5 Identification of Potential Contaminants ZionSolutions TSD-11-001, Technical Support Document for Potential Radionuclides of Concern During the Decommissioning of the Zion Station (Reference 23) was prepared and approved in October 2012. The purpose of this document was to establish the basis for an initial suite of potential ROC for the decommissioning. Industry guidance was reviewed as well as the analytical results from the sampling of various media from past plant operations.
Based on the elimination of some of the theoretical neutron activation products, noble gases and radionuclides with a half-life of less than two years, an initial suite of potential ROC for the decommissioning of the ZNPS was prepared.
The site characterization showed that the radionuclide identified in most of the samples was Cs-137. For all of the characterization samples, the concentrations of Cs-137 were typical of the concentrations determined from off-site locations and fallout as documented by TSD-13-004, Examination of Cs-137 Global Fallout In Soils At Zion Station (Reference 24).
Characterization results also identified Co-60 at concentrations greater than MDC at several locations.
Cs-137 deposition resulting from global fallout is thought to be the source of most of the Cs-137 encountered in samples collected in the open lands surrounding ZNPS. Geological deposition, regional concentrations and transport mechanisms are well documented and the subject of numerous publications and studies. However, as a conservative measure, Cs-137 resulting from fallout or background was not subtracted from analytical results for FSS at ZNPS.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 In accordance with the LTP, a minimum of 10% of the non-parametric sample population or any sample with a SOF of 0.1 or greater was sent to an off-site laboratory for HTD ROC analysis. This process was done to verify that the surrogate ratios between HTD ROC and the ETD ROC as established in the LTP remained valid and conservative even with changing environmental conditions. For soil samples with positive results for both an HTD ROC and the corresponding surrogate radionuclide, the HTD to surrogate ratio would have been derived. If the derived surrogate ratio had exceeded the maximum surrogate ratios presented in LTP Chapter 5, Table 5-15, then consideration would have been given to using a survey unit specific surrogate ratio after sufficient investigation and consultation with the NRC.
Analyses for HTD radionuclides positively identified Ni-63 in some samples, but the threshold described above was not encountered in any of the sixty-seven (67) survey units addressed by Phase 4. Accordingly, the maximum ratios from LTP Chapter 5, Table 5-15 were used for all surrogate calculations During the FSS implementation, areas of interest were scanned with portable, hand-held radiation detection meters. Prior to scanning, background levels were determined, and investigation levels set in accordance with the Sample Plan. Areas were then scanned for elevated readings. When an elevated area was found, the area was marked, and a sample was collected at that location for gamma spectroscopy analysis and further evaluation.
3.6 Radiological Release Criteria All FSS of the surface soil in open land survey units submitted in this Phase 4 FSSR were designed to the OpDCGL for surface soils, and all results were compared to this value.
However, since the release criteria were based on the BcDCGL (25 mrem/year), surpassing the OpDCGL did not disqualify a survey unit from meeting the release criteria provided that the Elevated Measurement Comparison (EMC) was not exceeded. Discrete, elevated areas of contamination were identified in several of these survey units during FSS, however all residual radioactivity greater than the OpDCGL concentrations was remediated prior to demonstrating compliance. The EMC was calculated during the FSS of several of these survey units (10207A, 10213B, 10220I, 10221A, 10221D and 12203A); however, as all soils identified as exceeding the OpDCGLs were remediated in these survey units, the EMC was not used to demonstrate compliance.
4 Final Status Survey Protocol 4.1 Data Quality Objectives The DQO process as outlined in Section 2 of this report was applied for each FSS Sample Plan and contained basic elements common to all FSS Sample Plans at ZSRP. An outline of those elements that are presented in the ZSRP FSS Sample Plans are as follows:
State the Problem 53
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 The problem: To demonstrate that the level of residual radioactivity in a survey unit does not exceed the release criteria of 25 mrem/year TEDE and that the potential dose from residual radioactivity is ALARA.
Stakeholders: The primary stakeholders interested in the answer to this problem are ZionSolutions LLC, Exelon, the Illinois Environmental Management Agency (IEMA) and the NRC.
The Planning Team: The planning team consisted of the assigned RE with input from other C/LT personnel as well as the Safety Department. The primary decision makers were the Technical Lead/RE with input from the C/LT Manager.
Schedule: The approximate time projected to mobilize, implement, and assess an FSS unit was typically four (4) days.
Resources: The following resources were necessary to implement an FSS Sample Plan:
- RE to prepare the plan and evaluate data,
- C/LT Field Supervisor to monitor and coordinate field activities,
- Survey Mapping/computer aided design (CAD) Specialist to prepare survey maps, layout diagrams, composite view drawings, and other graphics as necessary to support design and reporting,
- C/LT Technicians to perform survey activities, collect survey measurement data, and collect media samples,
- Chemistry/Analysis laboratory Staff to analyze samples as necessary.
Identify the Decision Principal Study Question: Are the residual radionuclide concentrations found in the soil equal to or below site-specific DCGLs for surface soils?
Alternate Actions: Alternative actions included failure of the survey unit, remediation, reclassification, and resurvey.
The Decision: If the survey unit failed to demonstrate compliance with the release criteria, then the survey unit would not be suitable for unrestricted release. The DQA process was reviewed to identify the appropriate additional action or combination of actions.
Identify Inputs to the Decision Information Needed: The survey unit required evaluation of residual activity and its surface area. The characterization surveys and HSA were preliminary sources of information for FSS. In some cases, new measurements of sample media were needed to determine the concentration and variability for those radionuclides potentially present at the site at the time of FSS.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Historical Information: The classification as originally identified in the HSA and the verification of that classification during characterization. A summary of site processes or incidents that occurred in the survey unit.
Radiological Survey Data: The current radiological survey data from the HSA and from characterization was used to develop a sample size for FSS.
Radionuclides of Concern: The ROC for the FSS of open land areas are presented in Section 2.2, Table 2-4, of this report.
Basis for the Action Level: The action levels for the FSS of Class 1, 2 and 3 open land areas were the OpDCGL, or a percentage of the OpDCGL (100% for survey units designated as Class 1 or Class 2 and 50% for Class 3 survey units).
During FSS, concentrations for HTD ROC, Ni-63 and Sr-90, were inferred using a surrogate approach. As presented in the LTP, Cs-137 is the principle surrogate radionuclide for Sr-90 and Co-60 is the principle surrogate radionuclide for Ni-63. The mean, maximum and 95%
Upper Confidence Level (UCL) of the surrogate ratios for concrete core samples taken in the Auxiliary Building basement were calculated in ZionSolutions TSD-14-019, Radionuclides of Concern for Soil and Basement Fill Model Source Terms (Reference 25) and are presented in Table 4-1. The maximum ratios were used in the surrogate calculations during the FSS of the Phase 4 open land survey units. No area specific ratios were determined by continuing characterization.
Table 4-1, Surrogate Ratios Auxiliary Building Ratios Mean Max 95% UCL Ni-63/Co-60 44.143 180.450 154.632 Sr-90/Cs-137 0.001 0.002 0.002 For the FSS of the open land survey units in this report, the surrogate OpDCGLs for Co-60 and Cs-137 was computed based on the maximum ratios from Table 4-1.
The equation for calculating a surrogate DCGL is as follows:
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Equation 1 1
=
1 2 3
[( ) + ( ) + ( ) + ( )]
2 3 Where: DCGLSur = Surrogate radionuclide DCGL DCGL2,3n = DCGL for radionuclides to be represented by the surrogate Rn = Ratio of concentration (or nuclide mixture fraction) of radionuclide n to surrogate radionuclide Using the OpDCGLs presented in Table 2-1 and the maximum ratios from Table 4-1, the following surrogate calculations were performed:
Equation 2 1
(137) = = 3.622 /
1 0.002
[(3.630 )+( )]
(137) 3.095(90)
The surrogate OpDCGL that was used for Cs-137 in the survey units for direct comparison of sample results to demonstrate compliance was 3.622 pCi/g.
Equation 3 1
(60) = = 0.898 /
1 180.45
[(1.091 )+( )]
(60) 914.458(63)
The surrogate OpDCGL that was used for Co-60 in the survey units for direct comparison of sample results to demonstrate compliance was 0.898 pCi/g.
The action level for investigation in a Class 1 open land survey unit was the OpDCGL. The surrogate DCGL for Co-60 while inferring Ni-63 was 0.898 pCi/g, and the surrogate DCGL for Cs-137 while inferring Sr-90 was 3.622 pCi/g.
Investigation Levels: The investigation levels used for the FSS of Phase 4 survey units were designated in accordance with Table 5-25 of the LTP, recreated below as Table 4-2.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 4-2 FSS Investigation Levels Classification Scan Investigation Levels Direct Investigation Levels Class 1 >Operational DCGL or >MDCscan if MDCscan is greater than Operational >Operational DCGLW DCGL
>Operational DCGL or >MDCscan if Class 2 MDCscan is greater than Operational >Operational DCGLW DCGL
>Operational DCGL or >MDCscan if Class 3 MDCscan is greater than Operational >0.5 Operational DCGLW DCGL Sampling and Analysis Methods to Meet the Data Requirements: Surface soil samples were collected down to a depth of 0.15-meters (6-inches) and analyzed for gamma-emitting radionuclides by on-site or off-site gamma spectroscopy. The media consisted of soils and sand as required to complete the FSS. Subsurface soil sampling was collected using hand-auger or GeoProbe technology, typically to a depth of 1-meter. Several samples were acquired of subsurface soils surrounding buried basement foundations to deeper depths.
The target MDC for the analysis of sample media using laboratory instruments was 10% of the applicable OpDCGL. If necessary, measurement results with associated MDC that exceeded these values were accepted as valid data after evaluation by C/LT Supervision.
In accordance with LTP Chapter 5, Section 5.1, 10% of the volumetric samples acquired for FSS or any sample with a SOF in excess of 0.1 when compared against the OpDCGL (OpSOF) were sent off-site for HTD ROC analysis. These analyses aimed to reaffirm that the radionuclide mix was not significantly different than that assumed in the LTP.
All activities were subject to the requirements of the QAPP for Characterization and FSS, which requires, among other things, the use of trained technicians, calibrated instruments, and procedures. In addition to these requirements, a minimum of 5% of the required number of samples were selected for Quality Control (QC) evaluation. At least one (1) duplicate soil sample was collected in each survey unit for QC evaluation.
Define the Boundaries of the Survey Boundaries of the Survey: The actual physical boundaries as stated for each survey unit.
Temporal Boundaries: The times and dates the survey was performed. Scanning and sampling in a survey unit was normally performed only during daylight and dry weather.
Constraints: The most common constraints were the weather, brush or undergrowth, and standing water in a survey unit.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Develop a Decision Rule Decision Rule: If any measurement data results exceeded the release criteria, the DQA process would be used to evaluate alternative actions.
Specify Tolerable Limits on Decision Errors The Null Hypothesis: Residual radioactivity in the survey unit exceeds the release criteria.
Type I Error: This is also known as the error. This is the error associated with incorrectly concluding the null hypothesis has been rejected. In accordance with LTP Section 5.6.4.1.1, the error was set at 0.05 (5%).
Type II Error: This is also known as the error. This is the error associated with incorrectly concluding the null hypothesis has been accepted. In accordance with LTP Section 5.6.4.1.1, the error was set at 0.05 (5%).
The Lower Bound of the Gray Region (LBGR): The LBGR was set at 50% of the OpDCGL.
In using the unity rule, the OpDCGL becomes one (1) and the LBGR is set as 0.5.
Optimize Design Type of Statistical Test: The Sign Test was selected as the non-parametric statistical test for FSS. The Sign Test is conservative as it increases the probability of incorrectly accepting the null hypothesis (i.e., the conclusion will be that the survey unit does not meet the release criteria) and does not require the selection or use of a background reference area.
Number of Non-Parametric Samples: In the majority of the open land survey units addressed by this Phase 4 FSSR, 17 surface soil samples were required for the non-parametric statistical test (sample size N = 17). In ten (10) of the sixty-seven (67) survey units (survey units 10204A, 10206A, 10207A, 10208A, 10212A, 10212C, 10212D, 10220A, 10221A, and 12201E), between eighteen (18) and twenty-four (24) surface soil samples were required for the non-parametric statistical test. In one (1) of the survey units (survey unit 12203A), thirty (30) surface soil samples were required for the non-parametric statistical test. The locations of the samples were determined using software VSP.
Number of Judgmental Samples and Locations: The selection of judgmental samples was at the discretion of the cognizant RE. Locations chosen for sampling were usually areas of interest (small piles, trenches, etc.) and any areas of elevated radiation identified by scan.
Number of Scan Areas and Locations: Scan frequencies were prescribed in accordance with LTP Chapter 5, Section 5.6.4.4 and Table 5-24. Minimum scan frequencies are presented in Table 4-3.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 4-1, Recommended Scan Coverage Area Classification Surface Scans Class 1 100%
10% to 100%,
Class 2 Systematic and Judgmental Class 3 Judgmental Number of Samples for Quality Control: The implementation of quality control measures as referenced by LTP Chapter 5, Section 5.9 and the QAPP included the collection of a soil sample for split sample analysis on 5% of the soil samples taken in a survey unit with the locations selected at random.
Power Curve: The Prospective Power Curve, developed using characterization data and VSP, showed adequate power for the survey design in each of the survey units.
4.2 Survey Unit Designation and Classification Procedure ZS-LT-300-001-002, Survey Unit Classification (Reference 26), defines the decision process for classifying an area in accordance with the LTP and MARSSIM.
During the FSS of areas submitted for the Phase 4 FSSR, several survey units were reclassified during the performance of FSS. All changes to classification were to a more rigorous classification. All but seven (7) survey units of the sixty-seven (67) addressed by this Phase 4 FSSR were designated as Class 1.
4.3 Background Determination During FSS area scanning, ambient backgrounds were determined. As a conservative measure, technicians established an Alarm Set Point (ASP) for the Ludlum Model 2350-1 instrument coupled to a Ludlum Model 44-10 NaI detector at the MDCR of the instrument plus the background for each scan area. The results of scans in each survey unit addressed by this Phase 4 FSSR is provided in the Release Records.
4.4 Final Status Survey Sample Plans The level of effort associated with planning a survey is based on the complexity of the survey and nature of the hazards. Guidance for preparing FSS plans is provided in procedure ZS-LT-300-001-001 Final Status Survey Package Development. The FSS plan uses an integrated sample design that combines scanning surveys and sampling.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 4.5 Survey Design 4.5.1 Determination of Number of Data Points The number of soil samples for FSS was determined in accordance with procedure ZS-LT-300-001-001 Final Status Survey Package Development and MARSSIM. The relative shift (/) for the survey unit data set is defined as shift (), which is the Upper Boundary of the Gray Region (UBGR), or the OpDCGL (SOF of 1), minus the LBGR (SOF of 0.5),
divided by sigma (), which is the standard deviation of the data set used for survey design (characterization). If the calculated relative shift for a survey unit was greater than 3, then a value of 3 was used as the adjusted /.
A breakdown of the number of soil samples collected for the Phase 4 survey units is provided in Table 4-4 below.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 4-4, Number of Surface Soil Samples for FSS Survey Area Class # of Samples Spacing Description Unit (m2) (initial/Final) NP Judg. Inv. QC (m) 10203A East Training Area 1,999 3/1 17 0 0 1 11.7 10203B East Training Area 1,977 3/1 17 6 0 2 11.6 10203C East Training Area 1,871 3/1 17 3 0 2 11.3 10203F East Training Area 1,888 3/1 17 0 0 1 11.3 10204A North Gate Area 2,231 3/1 19 0 0 2 11.6 10204B North Gate Area 1,549 3/1 17 0 2 2 10.3 10204C North Gate Area 1,547 3/1 17 0 0 1 10.3 10204D North Gate Area 1,545 3/1 17 0 1 2 10.2 10206A Station Construction Area 2,844 3/1 24 0 0 2 11.7 10206B Station Construction Area 1,837 3/1 17 0 4 3 11.2 10206C Station Construction Area 1,833 3/1 17 0 0 1 11.2 10206D Station Construction Area 1,829 3/1 17 0 1 2 11.1 10206E Station Construction Area 1,825 3/1 17 0 0 1 11.1 10207A North Warehouse Area 2,675 3/1 23 4 26 4 11.6 10207B North Warehouse Area 1,736 3/1 17 0 10 2 10.9 10207C North Warehouse Area 1,735 3/1 17 0 12 2 10.9 10207D North Warehouse Area 1,733 3/1 17 1 2 2 10.8 10207E North Warehouse Area 1,731 3/1 17 0 0 1 10.8 10208A South Warehouse Area 2,460 3/1 21 1 0 2 11.6 10208B South Warehouse Area 1,835 3/1 17 0 0 1 11.2 10208C South Warehouse Area 1,868 3/1 17 0 4 2 11.3 10208D South Warehouse Area 1,827 3/1 17 0 10 2 11.1 10209C Restricted Area South of Gate House 1,970 3/1 17 0 15 2 11.6 10212A NE Corner of Exclusion Area - Lakeshore 9,550 3/2 18 0 2 2 24.8 10212B VCC Construction Area 16,154 3/3 17 0 4 2 Random 10212C NE Corner of Exclusion Area - Lakeshore 1,744 3/1 19 0 0 2 10.3 10212D NE Corner of Exclusion Area - Lakeshore 1,490 3/1 22 2 0 2 8.8 10213A NE Corner of Exclusion Area 5,730 3/2 17 0 0 1 19.7 10213B NE Corner of Exclusion Area 1,994 3/1 17 3 27 3 11.6 10213C NE Corner of Exclusion Area 1,934 3/1 17 9 6 3 11.5 10214A Construction Parking Area 8,542 3/2 17 0 10 2 24.1 10214B Construction Parking Area 7,372 3/2 17 0 1 2 22.4 10214C Construction Parking Area 7,579 3/2 17 0 6 2 22.7 10214D Construction Parking Area 8,946 3/2 17 1 6 2 24.7 10214E Construction Parking Area 1,989 3/1 17 0 2 2 11.6 10214F Construction Parking Area 1,661 3/1 17 0 1 2 10.6 10220A SE Corner of Exclusion Area - Lakeshore 2,025 3/1 23 0 13 3 10.1 10220H SE Corner of Exclusion Area - Lakeshore 2,088 3/1 17 4 0 2 11.9 10220I SE Corner of Exclusion Area - Lakeshore 2,060 3/1 17 5 16 2 11.8 61
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 4-4 (continued), Number of Surface Soil Samples for FSS Survey Area Class # of Samples Spacing Description Unit (m2) (initial/Final) NP Judg. Inv. QC (m) 10221A South of Protected Area - Inland 1,976 3/1 22 12 9 6 10.2 10221C South of Protected Area - Inland 1,959 3/1 17 8 13 3 11.5 10221D South of Protected Area - Inland 1,697 3/1 17 7 22 3 10.7 12104 North Half of Unit 2 Containment 1,940 1/1 17 0 0 1 11.5 12105 South Half of Unit 2 Containment 1,938 1/1 17 0 0 1 11.5 12106 North Half of Fuel & Auxiliary Buildings 1,936 1/1 17 0 0 1 11.5 12107 South Half of Fuel & Auxiliary Buildings 1,934 1/1 17 0 0 1 11.5 12108 North Half of Unit 1 Containment 1,933 1/1 17 0 0 1 11.5 12109 South Half of Unit 1 Containment 1,931 1/1 17 0 0 1 11.5 12110 Yard Between Unit 1 Containment and Turbine 1,740 1/1 17 0 0 1 10.9 12111 South Yard Area Northeast of Gate House 1,964 1/1 17 3 0 2 11.6 12201A North Protected Area Yard 1,992 2/1 17 0 0 1 11.6 12201B North Protected Area Yard 1,995 2/1 17 0 0 1 11.6 12201C North Protected Area Yard 1,968 2/1 17 0 6 2 11.6 12201D North Protected Area Yard 1,842 2/1 17 0 5 3 11.2 12201E North Protected Area Yard 1,902 2/1 18 0 2 2 11.0 12202A Gate House and Southwest Yard 1,998 2/1 17 0 0 1 11.6 12202B Gate House and Southwest Yard 1,999 2/1 17 0 0 1 11.7 12202C Gate House and Southwest Yard 1,894 2/1 17 0 0 1 11.3 12202D Gate House and Southwest Yard 1,663 2/1 17 0 0 1 10.6 12202E Gate House and Southwest Yard 1,845 2/1 17 2 0 2 11.2 12202F Gate House and Southwest Yard 1,858 2/1 17 5 0 2 11.2 12203A Under Service Building and Southeast Yard 1,988 2/1 30 0 14 3 8.7 12205A Area Under the Turbine Building 1,809 2/1 17 0 0 1 11.1 12205B Area Under the Turbine Building 1,814 2/1 17 0 0 1 11.1 12205C Area Under the Turbine Building 1,818 2/1 17 0 0 1 11.1 12205D Area Under the Turbine Building 1,821 2/1 17 0 0 1 11.1 12205E Area Under the Turbine Building 1,825 2/1 17 0 4 2 11.1 62
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 4.5.2 Sample Locations Locations of the samples were determined using software VSP. VSP software imports a topographical map of the selected survey area and designates the sample locations with coordinates and bearings based on the Illinois State Plane System NAD 1983 East. Pacific Northwest National Laboratory (PNNL) created VSP for the United States Department of Energy. For those locations where access was impractical or unsafe, sample locations were relocated to the closest adjacent suitable location. Sample locations were identified using GPS coordinates and are consistent with the Illinois State Plane System. Once located, sample points were physically marked as required by ZS-LT-300-001-001 and graphically plotted using drafting software.
4.6 Instrumentation Radiation detection and measurement instrumentation for performing FSS were selected to provide both reliable operation and adequate sensitivity to detect the ROC identified at the site at levels sufficiently below the OpDCGL. Detector selection was based on detection sensitivity, operating characteristics and expected performance in the field.
The DQO process included the selection of instrumentation appropriate for the type of measurement to be performed (i.e., scan measurements and sample analysis) that were calibrated to respond to a radiation field under controlled circumstances, evaluated periodically for adequate performance to established quality standards, and sensitive enough to detect the ROC with a sufficient degree of confidence.
Electronic data logging was used to the extent practicable to automatically record measurements to minimize transcription errors.
Specific implementing procedures controlled the issuance, use, and calibration of instrumentation used for FSS. The specific DQOs for instruments were established early in the planning phase for FSS activities, implemented by standard operating procedures and executed in the FSS Sample Plan.
4.6.1 Detector Efficiencies The Ludlum Model 2350-1 Data Logger coupled with the Ludlum Model 44-10 2-inch x 2-inch NaI Gamma Scintillation detector was selected as the primary radiation detection instrumentation for performing scanning for open land survey units for FSS at ZNPS.
Instrument efficiencies (i) are derived from the surface emission rate of the radioactive source(s) used during the instrument calibration. Total efficiency (t) is calculated by multiplying the instrument efficiency (i) by the surface efficiency (s) commensurate with the radionuclides beta energy using the guidance provided in ISO 7503-1, Part 1, Evaluation of Surface Contamination, Beta-emitters (maximum beta energy greater than 0.15 MeV) and alpha-emitters (Reference 27).
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 4.6.2 Detector Sensitivities The evaluation of open land areas required a detection methodology of sufficient sensitivity for the identification of small areas of potentially elevated activity. Scanning measurements were performed by passing a hand-held detector, primarily the Ludlum Model 44-10 NaI detector, in gross count rate mode across the land surface under investigation. The centerline of the detector was maintained at the ground to detector distance detailed in the sample plan and moved from side to side in a 1-meter wide pattern at a typical scan rate of 0.25 m/sec or 0.5 m/sec. The audible and visuals signals were monitored for detectable increases in count rate. An observed count rate increase resulted in further investigation to verify findings and to define the level and extent of residual radioactivity.
An a priori determination of scanning sensitivity was performed to ensure that the measurement system (including the surveyor) was able to detect concentrations of radioactivity at levels below the regulatory release limit. The specified performance level and surveyor efficiency was expressed in terms of scan MDCR. This sensitivity is the lowest count rate that can be reliably detected at any given background by the measurement system.
The specified MDCR correlates to the targeted MDC.
This approach represents the surface scanning process for land areas defined in NUREG-1507, Minimum Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions (Reference 28). The gamma scan MDCR is discussed in detail in ZionSolutions TSD-11-004, Ludlum Model 44-10 Detector Sensitivity (Reference 29) which examines the gamma sensitivity for a 2-inch x 2-inch NaI detector to several radionuclide mixtures of Co-60 and Cs-137 at various detector distances and scan speeds. TSD-11-004 provides MDCR values for the expected ZNPS soil mixture based on detector background condition, scan speed, soil depth (0.15-meters), soil density (1.6 g/cm3) and detector distance to the surface of interest.
4.6.3 Instrument Maintenance and Control Control and accountability of survey instruments were maintained to assure the quality and prevent the loss of data. All personnel operating radiological instruments, analysis equipment, measurement location equipment etc., were qualified to operate any assigned equipment and recognize off-normal results and indications.
4.6.4 Instrument Calibration Instruments and detectors were calibrated for the radiation types and energies of interest or to a conservative energy source. Instrument calibrations were documented with calibration certificates and/or forms and maintained with the instrumentation and project records.
Calibration labels were also attached to all portable survey instruments. Prior to using any survey instrument, the current calibration was verified, and all operational checks were performed.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Instrumentation used for FSS were calibrated and maintained in accordance with approved ZionSolutions site calibration procedures. Radioactive sources used for calibration were traceable to the NIST and were obtained in standard geometries to match the type of samples being counted. When a characterized high-purity germanium (HPGe) detector was used, suitable NIST-traceable sources were used for calibration, and the software set up appropriately for the desired geometry. If vendor services were used, these were obtained in accordance with purchasing requirements for quality related services, to ensure the same level of quality.
4.7 Survey Methodology 4.7.1 Scan Surveys The LTP specifies the minimum amount of scanning required for each class as summarized in Table 4-3. The total fraction of scanning coverage is determined during the DQO process with the amount and location(s) based on the likelihood of finding elevated activity during FSS. Sixty (60) of the sixty-seven (67) open land survey units addressed by this Report were classified as Class 1 and required 100% areal scan coverage. Of the remaining seven (7) open land survey units addressed by this Phase 4 FSSR, six (6) open land survey units were classified as Class 2 where 10% to 50% areal scan coverage were typically performed, and one open land survey unit was classified as Class 3, where 10% areal coverage was performed. Actual scan frequencies performed in each survey unit are presented in the Release Records.
For Class 1 and Class 2 survey units, the survey unit was broken down into manageable scan grids. Each scan grid was located with GPS and marked. Each scan grid was completely scanned to the extent possible. Walkover scans were conducted with a Ludlum Model 2350-1 instrument coupled to a Ludlum Model 44-10 Sodium Iodide (NaI) detector at a scanning speed of 0.25 m/sec or 0.5 m/sec. while observing the audible and visual indications of radioactivity. During the scanning, the technician recorded data and observations in a Field Log. This log documented field activities and other information pertaining to the survey.
Where an area could not be scanned due to the presence of a physical obstruction or standing water, a notation was made in the Field Log and subsequently denoted in the Release Record.
Areas with elevated readings were marked, and investigational samples were collected.
4.7.2 Soil Sampling In accordance with the FSS Sample Plan and applicable job aids, FSS technicians collected surface and subsurface soil samples at locations specified by the survey design. Each sample location was documented, along with soil conditions and observations, and a chain of custody was developed to maintain sample integrity.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 4.8 Quality Control Surveys The method used for evaluating QC split samples collected in support of the FSS program is specified in the QAPP for Characterization and FSS. QC split data was assessed using criteria taken from the NRC Inspection Manual, Inspection Procedure 84750, Radioactive Waste Treatment, and Effluent and Environmental Monitoring (Reference 30).
A minimum of 5% of the sample locations used in the FSS design were selected randomly and submitted as splits. Split samples taken for FSS were obtained from one location, homogenized, divided into separate containers, and treated as separate samples. These samples were then used to assess errors associated with sample heterogeneity, sample methodology, and analytical procedures. It was desirable that when analyzed, there is agreement between the splits resulting in data acceptance. If there was no agreement between the samples, the RE evaluated the magnitude and impact on survey design, the implementation and evaluation of results as well as the need to perform confirmatory sampling. If the RE had determined that the discrepancy affected quality or was detrimental to the implementation of FSS, then a Condition Report would have been issued. This threshold was not encountered during the FSS of Phase 4 open land survey units.
To maintain the quality of the FSS, isolation and control measures were implemented prior to and during survey activities upon completion of FSS until there was no risk of recontamination or upon license termination. Following FSS, and until the area is released, a semi-annual surveillance will be performed on completed FSS survey units. This includes an inspection of area postings, inspection of the area for signs of dumping or disturbance and biased sampling. In the event that isolation and control measures were compromised, a follow-up survey may be performed after evaluation.
5 Survey Findings Procedure ZS-LT-300-001-004, Final Status Survey Data Assessment, provided guidance to C/LT personnel to interpret survey results using the DQA process during the assessment phase of FSS activities.
The DQA process was the primary evaluation tool to determine that data is of the right type, quality and quantity to support the objectives of the FSS Sample Plan. The five steps of the DQA process are:
- 1. Review the Sample Plan DQOs and the survey design,
- 2. Conduct a preliminary data assessment,
- 3. Select the statistical test,
- 4. Verify the assumptions of the statistical test,
- 5. Draw conclusions from the data.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Data validation descriptors described in MARSSIM Table 9.3 were used during the DQA process to verify and validate collected data as required by the QAPP for Characterization and FSS.
5.1 Survey Data Conversion During the data conversion, the RE evaluated raw data for problems or anomalies encountered during Sample Plan activities (sample collection and analysis, handling and control, etc.) including the following:
- Recorded data,
- Missing values,
- Deviation from established procedure, and
- Analysis flags.
Once resolved, initial data conversion, which is part of preliminary data assessment, was performed and consisted of converting the data into units relative to the release criteria (e.g.,
pCi/g) and calculating basic statistical quantities (e.g., mean, median, standard deviation).
Table 5-1 provides a summary of the basic statistical properties for the FSS of the sixty-seven (67) Phase 4 open land survey units.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 5-1, Basic Statistical Properties for FSS of Phase 4 Open Land Survey Units Radionuclide Statistical Summary Survey Mean Max # OpSOF Co-60 Cs-137 Description Unit OpSOF OpSOF >1 Max Mean St. Dev. Max Mean St. Dev.
(pCi/g) (pCi/g) (pCi/g) (pCi/g) (pCi/g) (pCi/g) 10203A East Training Area 0.038 0.092 0 6.95E-02 1.78E-02 1.90E-02 9.90E-02 4.41E-02 3.00E-02 10203B East Training Area 0.050 0.127 0 6.48E-02 2.21E-02 2.30E-02 2.18E-01 5.17E-02 5.70E-02 10203C East Training Area 0.037 0.090 0 5.00E-02 1.79E-02 1.60E-02 8.18E-02 3.20E-02 2.20E-02 10203F East Training Area 0.028 0.078 0 4.89E-02 1.55E-02 1.40E-02 3.56E-02 1.02E-02 1.10E-02 10204A North Gate Area 0.044 0.085 0 5.57E-02 2.29E-02 1.40E-02 6.17E-02 2.45E-02 1.90E-02 10204B North Gate Area 0.037 0.095 0 6.02E-02 1.77E-02 1.90E-02 6.17E-02 2.94E-02 2.10E-02 10204C North Gate Area 0.056 0.102 0 6.50E-02 3.52E-02 1.90E-02 1.14E-01 3.73E-02 2.40E-02 10204D North Gate Area 0.044 0.084 0 6.36E-02 2.37E-02 1.70E-02 5.68E-02 2.48E-02 1.90E-02 10206A Station Construction Area 0.061 0.422 0 5.18E-02 2.11E-02 1.70E-02 1.52E+00 9.90E-02 3.04E-01 10206B Station Construction Area 0.048 0.117 0 6.61E-02 2.64E-02 2.30E-02 7.91E-02 3.97E-02 2.20E-02 10206C Station Construction Area 0.058 0.106 0 5.18E-02 2.70E-02 1.60E-02 9.11E-02 5.55E-02 2.40E-02 10206D Station Construction Area 0.069 0.198 0 1.56E-01 3.99E-02 3.40E-02 1.26E-01 6.45E-02 3.10E-02 10206E Station Construction Area 0.028 0.104 0 8.29E-02 1.73E-02 2.20E-02 5.37E-02 1.70E-02 1.70E-02 10207A North Warehouse Area 0.136 1.345 1 (1) 1.51E-01 3.31E-02 3.20E-02 4.26E+00 3.14E-01 8.88E-01 10207B North Warehouse Area 0.038 0.085 0 6.19E-02 2.05E-02 2.10E-02 1.03E-01 3.65E-02 2.50E-02 10207C North Warehouse Area 0.069 0.150 0 1.04E-01 3.87E-02 3.00E-02 1.78E-01 6.00E-02 3.80E-02 10207D North Warehouse Area 0.052 0.110 0 5.88E-02 2.59E-02 1.90E-02 8.72E-02 4.06E-02 2.80E-02 10207E North Warehouse Area 0.044 0.096 0 6.78E-02 2.65E-02 2.10E-02 6.34E-02 3.34E-02 1.60E-02 10208A South Warehouse Area 0.046 0.089 0 6.13E-02 2.71E-02 1.70E-02 8.74E-02 3.43E-02 2.30E-02 10208B South Warehouse Area 0.047 0.095 0 6.05E-02 2.67E-02 2.20E-02 9.88E-02 3.76E-02 3.60E-02 10208C South Warehouse Area 0.045 0.083 0 6.33E-02 2.58E-02 2.00E-02 5.92E-02 2.27E-02 2.10E-02 10208D South Warehouse Area 0.042 0.086 0 5.35E-02 2.44E-02 1.70E-02 5.54E-02 2.37E-02 1.50E-02 10209C Restricted Area South of Gate House 0.060 0.117 0 7.23E-02 3.19E-02 2.20E-02 1.48E-01 6.04E-02 3.40E-02 10212A NE Corner of Exclusion Area - Lakeshore 0.048 0.092 0 3.87E-02 2.01E-02 1.50E-02 1.44E-01 5.54E-02 3.70E-02 10212B VCC Construction Area 0.039 0.097 0 6.92E-02 2.19E-02 1.90E-02 5.25E-02 2.35E-02 1.60E-02 10212C NE Corner of Exclusion Area - Lakeshore 0.060 0.202 0 5.97E-02 2.00E-02 1.60E-02 4.90E-01 9.46E-02 1.06E-01 68
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 5-1 (continued), Basic Statistical Properties for FSS of Phase 4 Open Land Survey Units Radionuclide Statistical Summary Survey Mean Max # OpSOF Co-60 Cs-137 Description Unit OpSOF OpSOF >1 Max Mean St. Dev. Max Mean St. Dev.
(pCi/g) (pCi/g) (pCi/g) (pCi/g) (pCi/g) (pCi/g) 10212D NE Corner of Exclusion Area - Lakeshore 0.082 0.150 0 8.32E-02 2.53E-02 1.90E-02 4.00E-01 1.60E-01 1.20E-01 10213A NE Corner of Exclusion Area 0.081 0.188 0 7.02E-02 2.76E-02 1.90E-02 4.54E-01 1.55E-01 1.36E-01 10213B NE Corner of Exclusion Area 0.151 1.014 1 (1) 5.00E-02 2.27E-02 1.80E-02 3.47E+00 4.31E-01 8.05E-01 10213C NE Corner of Exclusion Area 0.096 0.187 0 6.23E-02 2.93E-02 2.20E-02 5.85E-01 1.90E-01 1.37E-01 10214A Construction Parking Area 0.036 0.059 0 5.05E-02 1.84E-02 1.40E-02 8.22E-02 2.41E-02 2.20E-02 10214B Construction Parking Area 0.038 0.085 0 4.62E-02 2.00E-02 1.60E-02 8.78E-02 2.65E-02 2.90E-02 10214C Construction Parking Area 0.035 0.067 0 3.98E-02 1.78E-02 1.20E-02 9.50E-02 1.96E-02 2.60E-02 10214D Construction Parking Area 0.036 0.101 0 6.20E-02 1.59E-02 1.60E-02 1.45E-01 3.44E-02 4.10E-02 10214E Construction Parking Area 0.030 0.090 0 5.60E-02 1.50E-02 1.50E-02 5.87E-02 2.05E-02 1.80E-02 10214F Construction Parking Area 0.043 0.086 0 5.87E-02 2.05E-02 1.90E-02 5.44E-02 2.16E-02 1.60E-02 10220A SE Corner of Exclusion Area - Lakeshore 0.058 0.298 0 2.34E-01 3.36E-02 4.70E-02 6.63E-02 3.40E-02 2.10E-02 10220H SE Corner of Exclusion Area - Lakeshore 0.048 0.100 0 4.87E-02 2.47E-02 1.70E-02 1.22E-01 4.83E-02 3.10E-02 10220I SE Corner of Exclusion Area - Lakeshore 0.038 0.117 0 7.76E-02 2.00E-02 1.70E-02 9.76E-02 3.30E-02 2.70E-02 10221A South of Protected Area - Inland 0.059 0.189 1 (1) 8.32E-02 3.15E-02 2.00E-02 3.81E-01 5.48E-02 7.90E-02 10221C South of Protected Area - Inland 0.067 0.262 0 1.05E-01 3.19E-02 2.90E-02 4.32E-01 7.78E-02 1.20E-01 10221D South of Protected Area - Inland 0.045 0.110 0 4.45E-02 2.35E-02 1.30E-02 2.28E-01 4.36E-02 5.40E-02 12104 North Half of Unit 2 Containment 0.034 0.068 0 5.14E-02 1.89E-02 1.80E-02 4.36E-02 1.55E-02 1.60E-02 12105 South Half of Unit 2 Containment 0.034 0.080 0 4.85E-02 1.91E-02 1.70E-02 5.74E-02 1.03E-02 1.70E-02 12106 North Half of Fuel & Auxiliary Buildings 0.031 0.053 0 4.35E-02 1.83E-02 1.50E-02 4.08E-02 1.28E-02 1.50E-02 12107 South Half of Fuel & Auxiliary Buildings 0.038 0.076 0 6.09E-02 2.54E-02 1.90E-02 4.07E-02 1.16E-02 1.30E-02 12108 North Half of Unit 1 Containment 0.027 0.046 0 3.33E-02 1.59E-02 1.20E-02 1.35E-02 3.53E-03 5.00E-03 12109 South Half of Unit 1 Containment 0.037 0.131 0 9.77E-02 2.43E-02 2.50E-02 3.78E-02 1.01E-02 1.30E-02 12110 Yard Between Unit 1 Containment and Turbine 0.053 0.114 0 7.99E-02 3.78E-02 2.30E-02 2.84E-02 7.66E-03 9.00E-03 12111 South Yard Area Northeast of Gate House 0.031 0.061 0 4.82E-02 1.76E-02 1.60E-02 2.82E-02 7.52E-03 1.00E-02 12201A North Protected Area Yard 0.035 0.077 0 4.61E-02 2.12E-02 1.50E-02 4.45E-02 1.25E-02 1.40E-02 12201B North Protected Area Yard 0.030 0.068 0 5.15E-02 1.61E-02 1.70E-02 3.61E-02 1.12E-02 1.40E-02 69
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 5-1 (continued), Basic Statistical Properties for FSS of Phase 4 Open Land Survey Units Radionuclide Statistical Summary Survey Mean Max # OpSOF Co-60 Cs-137 Description Unit OpSOF OpSOF >1 Max Mean St. Dev. Max Mean St. Dev.
(pCi/g) (pCi/g) (pCi/g) (pCi/g) (pCi/g) (pCi/g) 12201C North Protected Area Yard 0.016 0.036 0 1.75E-02 6.54E-03 6.00E-03 6.60E-02 1.34E-02 1.60E-02 12201D North Protected Area Yard 0.015 0.037 0 1.80E-02 4.09E-03 5.00E-03 5.38E-02 1.21E-02 1.60E-02 12201E North Protected Area Yard 0.003 0.039 0 2.79E-02 5.79E-03 8.00E-03 8.12E-02 1.17E-02 2.00E-02 12202A Gate House and Southwest Yard 0.032 0.094 0 8.10E-02 2.09E-02 2.40E-02 4.75E-02 7.12E-03 1.30E-02 12202B Gate House and Southwest Yard 0.032 0.072 0 4.86E-02 2.04E-02 1.50E-02 4.24E-02 7.50E-03 1.20E-02 12202C Gate House and Southwest Yard 0.039 0.091 0 4.79E-02 2.47E-02 1.60E-02 5.65E-02 1.14E-02 1.40E-02 12202D Gate House and Southwest Yard 0.039 0.092 0 7.43E-02 2.50E-02 2.10E-02 4.37E-02 1.65E-02 1.50E-02 12202E Gate House and Southwest Yard 0.024 0.046 0 3.23E-02 1.28E-02 1.10E-02 4.05E-02 1.32E-02 1.40E-02 12202F Gate House and Southwest Yard 0.039 0.074 0 5.52E-02 2.11E-02 1.60E-02 6.61E-02 2.31E-02 2.10E-02 12203A Under Service Building and Southeast Yard 0.037 0.078 0 5.22E-02 1.12E-02 1.20E-02 1.71E-01 4.21E-02 4.00E-02 12205A Area Under the Turbine Building 0.016 0.046 0 4.01E-02 6.37E-03 1.00E-02 1.73E-02 4.38E-03 5.00E-03 12205B Area Under the Turbine Building 0.023 0.055 0 3.90E-02 1.32E-02 1.30E-02 3.56E-02 5.50E-03 1.10E-02 12205C Area Under the Turbine Building 0.034 0.092 0 6.51E-02 2.12E-02 1.90E-02 4.53E-02 1.35E-02 1.40E-02 12205D Area Under the Turbine Building 0.031 0.075 0 6.71E-02 2.01E-02 1.70E-02 2.09E-02 4.67E-03 7.00E-03 12205E Area Under the Turbine Building 0.033 0.083 0 5.87E-02 1.88E-02 1.60E-02 3.59E-02 4.09E-03 1.00E-02 (1) Although the survey unit passed EMC, as a conservative measure, the soils in the identified elevated area were completely excavated and removed and replaced with clean fill imported from off-site.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 5.2 Survey Data Verification and Validation Items supporting DQO sample design and data were reviewed for completeness and consistency. These included:
- Classification history and related documents,
- Site description,
- Survey design and measurement locations,
- Analytic method and detection limits and that the required analytical method(s) were adequate for the radionuclides of concern,
- Sampling variability provided for the radionuclides of interest,
- QC measurements have been specified,
- Survey and sampling result accuracy have been specified,
- MDC limits,
- Field conditions for media and environment, and
- Field records.
Documentation, as listed, was reviewed to verify completeness and that it was legible:
- Field and analytical results,
- Chain-of-custody,
- Field Logs,
- Instrument issue, return and source check records,
- Instrument downloads, and
- Measurement results relative to measurement location.
After completion of these previously mentioned tasks, a Preliminary Data Assessment record was initiated. This record served to verify that all data was reported in standard units in relation to the DCGLs and that the calculation of the statistical parameters needed to complete data evaluation were completed which, at a minimum, included the following:
- The number of observations (i.e. samples or measurements),
- The range of observations (i.e. minimum and maximum values),
- Mean,
- Median, and
- Standard deviation.
In order to adequately evaluate the data set, consideration as additional options included the coefficient of variation, measurements of relative standing (such as percentile), and other statistical applications as necessary (frequency distribution, histograms, skew, etc.).
Finalization of the data review consisted of graphically displaying the data in distributions and percentiles plots.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 5.3 Anomalous Data/Elevated Scan Results and Investigation The following are summaries of anomalous data, elevated scan results and investigations performed during the FSS of the Phase 4 open land survey units. Details and specifics are provided in the individual Release Records.
Survey Unit 10203B During the gamma scan, one (1) location was identified with suspected higher than normal background readings. A separate scan was performed in this area and a surface soil sample was obtained at the location with the highest scan reading. The gamma spectroscopy results revealed no activity levels above MDC for Cs-137, Co-60 or Cs-134.
Survey Unit 10203C During the gamma scan, three (3) locations were identified with suspected higher than normal background readings. A separate scan was performed in these areas, and a surface soil sample was obtained at the location with the highest scan reading in each area. The gamma spectroscopy results for the judgmental samples revealed two (2) samples with activity levels above MDC for Cs-137 and no samples with activity levels above MDC for Co-60 or Cs-134. None of the judgmental sample results identified an OpSOF exceeding 0.1.
Survey Unit 10204B During the FSS of Class 1 open land survey unit 10204B, an investigation was performed following the observation of two (2) scan alarms. The source of the elevated activity was determined to be a layer of clay that retained elevated levels of Naturally Occurring Radioactive Material (NORM). Two (2) surface soil samples and one (1) QC soil sample were taken for the investigation. Gamma spectroscopy results revealed none of the investigative samples had activity levels above MDC for the ROC.
Survey Unit 10204D During the FSS of Class 1 open land survey unit 10204D, an investigation was performed following the observation of a scan alarm. A small elevated area was observed toward the western edge of a scan row. The activity was found to be from a small radioactive particle, located approximately 2 inches below the surface, reading 20,000 cpm. One (1) surface soil sample, one (1) surface soil QC sample and one (1) subsurface soil sample were taken following the removal of the particle. Gamma spectroscopy results of the investigative samples revealed one sample with detectable Cs-137 and less than MDC for all other ROC.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10206A During the FSS of Class 1 open land survey unit 10206A, the survey design identified a sample variability of 0.30, and N=17 for the number of systematic samples to be collected.
However, since the survey unit had a surface area of 2,844 m2, seven (7) additional samples were added to maintain the grid spacing of 11.7 m.
Survey Unit 10206B Several investigations occurred throughout this survey unit. Several scan alarms were observed. The second scan alarm could not be reproduced on subsequent scans. Four (4) investigational surface samples were taken as a result of these elevated scans. In addition to the surface samples, four (4) investigational subsurface samples were also collected at the areas with elevated scans. Gamma spectroscopy results of the investigative samples revealed one sample with detectable Cs-137 (but less than OpDCGL) and less than MDC for all other ROC. No additional investigations were conducted in this survey unit.
Survey Unit 10206D One (1) investigation occurred within this survey unit. A scan alarm was detected. An elevated area was identified as a 1 ft2 area. It was determined that the cause of the elevated scan result was due to a small particle of radioactive material approximately 3 inches below the surface. The particle was removed, and a surface investigative sample and subsurface investigative sample were collected at the location of the remediation. The gamma spectroscopy results for the two (2) investigative samples identified no activity above MDC for the ROC.
Survey Unit 10207A An investigation was performed based on a scan alarm. The activity was identified as a small radioactive particle located 3 inches below the surface. The particle was captured and removed. A surface soil sample was taken at the location of the particle, along with a QC split sample and a subsurface soil sample. The gamma spectroscopy results of these samples revealed a positive activity for Cs-137 in the QC split sample, with no activity above MDC for Co-60 and Cs-134.
A second investigation was performed based on another scan alarm. An elevated area of 1 ft2 was identified. A surface soil sample was taken at the location, along with a QC split sample and a subsurface soil sample. The gamma spectroscopy results for these samples indicated a positive activity for Cs-137 in the surface sample, with no activity above MDC for Cs-137, Co-60 and Cs-134 in the other samples.
A third investigation was performed based on the analytical results of a surface soil sample that exceeded an OpSOF of one. An additional fourteen (14) investigation surface soil samples were taken to bound the area of elevated activity. When analyzed by the on-site gamma spectroscopy system, three (3) of these samples also had activity above an OpSOF 73
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 of one. The area was calculated to be 6 m2 based on the GPS coordinates of the samples.
The average OpSOF in the bounded area was 1.383. The average activity for all ROC was below the DCGLEMC values. The conclusion of the investigation was that the survey unit would have passed the EMC, with a final dose for the survey unit of 2.50 mrem/year.
One (1) judgmental sample was taken in an area of higher background readings on the west end of the survey unit. In addition, three (3) judgmental samples were taken in the northern end of the survey unit. These samples were taken at the same distance from the railroad tracks as the identified elevated area in order to verify that there was no activity near the rail spur ballast in the north end of the survey unit. The gamma spectroscopy results for the judgmental samples showed two samples with low levels of Cs-137 activity, with the OpSOF below one for all four samples.
As a conservative measure, it was decided to remediate the activity identified in the elevated area. Six (6) to twelve (12) inches of soil was removed from a 14 m2 area surrounding the elevated area. Post-remediation scans showed no areas above the scan MDCR of the instruments. Ten (10) soil samples were taken in the remediated area. The results of these samples were compared to the surface OpDCGLs. None of these samples exceeded an OpSOF of one. As the source term that was prompting the application of the EMC process was removed, the additional dose to the mean of the survey unit BcSOF was not added.
Fifteen (15) systematic samples were relocated to the closest adjacent suitable location due to the original locations falling on the railroad spur which is made up of gravel and not soil.
In addition, one of the sample locations randomly selected for a subsurface sample was not accessible to the Geoprobe, so a sample was collected at an adjacent location.
Survey Unit 10207B During the FSS of Class 1 open land survey unit 10207B, an investigation was performed following the identification of two areas of elevated activity during scanning. Scanning performed during the investigation identified a small radioactive particle (16,000 cpm) 4 inches below the surface. The particle was captured. An investigation sample was taken at the location of the particle, with four (4) bounding samples taken 0.5 meter from the location of the particle. A QC split sample and a subsurface sample were also obtained as part of the investigation. Gamma spectroscopy results revealed that Cs-137 activity was present at low levels in three samples, and the activity level for Co-60 and Cs-134 was less than MDC in all five samples. The highest OpSOF for these samples was 0.098.
A second elevated area was also bounded by scan. An investigation sample was taken at the location of the highest scan reading, with four (4) bounding samples taken 0.5 meter from the initial sample. A subsurface sample was also obtained at the location of elevated scan.
Gamma spectroscopy results revealed that Cs-137 activity was present at low levels in one sample, and the activity level for Co-60 and Cs-134 was less than MDC in all five samples.
The highest OpSOF for these samples was 0.064.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10207C During the FSS of Class 1 open land survey unit 10207C, investigations were performed in three (3) locations following scan alarms. In the first two identified elevated areas, small radioactive particles were identified and captured. In both areas, a surface sample was obtained at the location of the particle, with four (4) bounding samples taken at a distance of 0.5 meters. One (1) subsurface sample was taken at the location of the highest scan reading in the area covered by the two investigations. Gamma spectroscopy results revealed that there were positively detected Cs-137 concentrations in nine (9) of the twelve (12) investigation samples. The highest OpSOF for these samples was 0.095.
A third elevated area was also identified in this survey unit during FSS. On a rescan of this area, the alarm was not verified. A surface sample was obtained at the scan location. Gamma spectroscopy results revealed no activity above MDC for the ROC in this sample.
Survey Unit 10207D During the FSS of Class 1 open land survey unit 10207D, an investigation was performed following the identification of two (2) areas of elevated activity. A surface and subsurface investigation sample was taken at each point along with a QC split sample. Gamma spectroscopy results revealed that three (3) of the samples had positive activity for Cs-137 with the highest OpSOF of 0.132. No further action was taken.
In addition, a judgmental sample was taken in an area that exhibited a higher background reading. This sample had positive activity for Cs-137 with an OpSOF of 0.063. No further action was taken.
Survey Unit 10208A The area of Class 1 survey unit 10208A is 2,460 m2, which is above the suggested size limitation of 2,000 m2 for Class 1 Open Land areas. Subsequently, additional samples were collected to maintain the grid spacing at approximately 11.6 m, which is the calculated result based on a survey unit size of 2,000 m2.
Of the twenty-one (21) systematic surface soil sample locations provided by VSP, eleven (11) samples were relocated to the closest adjacent suitable location because they fell on the rail spur, which consists of gravel and not soil.
In addition, one (1) judgmental surface sample was collected in the southwest corner of the survey unit.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10208B During the FSS of Class 1 open land survey unit 10208B, one (1) systematic sample was relocated to the closest adjacent suitable location due to the original location falling on the railroad spur which is made up of gravel and not soil.
Survey Unit 10208C During the FSS of Class 1 open land survey unit 10208C, an investigation was performed following a scan alarm. A 2 ft. x 6 ft. area was identified with a maximum count rate of 5,081 cpm. Four (4) surface soil samples were taken in this area. Gamma spectroscopy results revealed only one (1) sample with an activity level above MDC for Cs-137 and no samples with activity levels above MDC for Co-60 or Cs-134. Since the OpSOF for the investigation samples were all less than 1.0, with a maximum OpSOF of 0.086, no further action was deemed necessary.
Survey Unit 10208D During the FSS of Class 1 open land survey unit 10208D, investigations were performed following scan alarms. Four (4) small areas (each less than 1 ft2) were identified. One (1) surface and one (1) subsurface soil sample were taken in each area. Gamma spectroscopy results revealed all samples to be less than MDC for Cs-137, Co-60 and Cs-134. No further action was necessary.
Surface and subsurface investigation soil samples were also taken in six other locations where scan alarms occurred during the FSS readiness survey performed under an RA. These scan alarms were not reproduced during the FSS. Gamma spectroscopy results revealed only two (2) samples with activity levels above MDC for Cs-137 and no samples with activity levels above MDC for Co-60 or Cs-134. Since the OpSOF for the samples were all less than 1.0, with a maximum OpSOF of 0.108, no further action was deemed necessary.
Survey Unit 10209C An investigation was performed based on a scan alarm. The activity was identified as a small radioactive particle. The particle was captured and removed. An investigation sample was taken at the location of the particle, along with four (4) bounding samples taken approximately 1 m from the initial sample. A QC split sample and a subsurface sample were also obtained. Gamma spectroscopy results revealed that the activity for the ROC in the samples was below the OpDCGLs, therefore no further action was taken.
Another investigation was performed based on another scan alarm observed during a QC scan. The activity was identified as a small metallic object (nail) which was captured and removed. A surface soil sample was obtained at the location of the metallic object. The gamma spectroscopy results revealed positive Cs-137 activity, with an OpSOF less than one.
No further action was taken 76
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 A third investigation was performed following additional scan alarms during the QC scan.
An area approximately 3 m by 7 m was identified on the east end of the survey unit and an area approximately 1 m by 1 m was identified on the west end of the survey unit. Four (4) investigation samples were taken in the areas. Positive Cs-137 activity was detected in all four of the surface samples, with Co-60 activity detected above MDC in one sample. No sample exceeded an OpSOF of one. In addition, subsurface samples were taken at each location. The gamma spectroscopy results for the subsurface samples were less than MDC for the ROC. No further action was taken.
Survey Unit 10212A No remediation was performed in Class 2 open land survey unit 10212A. Investigations were performed following scan alarms. Two (2) small areas (each less than 100 cm2) were identified. One (1) surface and one (1) subsurface soil sample were taken at each location.
Gamma spectroscopy results revealed only one (1) sample with an activity level above MDC for Cs-137 and no samples with activity levels above MDC for Co-60 or Cs-134. Since the OpSOF for the investigation samples were all less than 1.0, with a maximum OpSOF of 0.089, no further action was deemed necessary.
In addition to the scan alarms addressed above, a technician documented two (2) scan alarms; however, the exact locations were not marked. The two locations were immediately re-scanned by the technician but the alarms could not be reproduced. Two other technicians scanned the row one week later and were not able to reproduce the alarms. Therefore, no further action was deemed necessary.
Finally, due to some areas in the survey unit being inaccessible for scan due to standing water and low-lying trees, two (2) additional scan rows were added. This enabled the survey to achieve the areal scan coverage requirement of 50%.
Survey Unit 10212B No remediation was performed in Class 3 open land survey unit 10212B. An investigation was performed following scan alarms. Two (2) areas with elevated activity were identified.
A 1-meter by 1-meter area, with a maximum count rate of 1,845 cpm, and a 1-meter by 8-meter area, with a maximum count rate of 1,802 cpm, were investigated. One (1) surface soil sample was taken in the smaller area and three (3) surface samples were taken in the larger area. A subsurface soil sample was also obtained in each area. Gamma spectroscopy results revealed only one (1) surface soil sample with an activity level above MDC for Cs-137. None of the samples had activity levels above MDC for Co-60 or Cs-134. Since the OpSOF for the investigation samples were all less than 0.5, with a maximum OpSOF of 0.059, no further action was deemed necessary.
Finally, due to some areas in the survey unit being inaccessible for scan due to standing water, two (2) additional scan areas were added. This enabled the survey to achieve the areal scan coverage requirement of 10%.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10212D One of the randomly selected locations for a subsurface sample, selected per the sample plan, was not available at the time of FSS. The Geoprobe machine could not access the area; therefore, a sample was collected at an adjacent location.
When the FSS of Class 1 open land survey unit 10212D was performed, the inlet pipe on the west end of the drainage ditch and the outlet pipe on the east end were both dammed. Two (2) pumps were removing water while the survey was in progress. However, due to the influx of ground water, it was not possible to remove all of the water from the drainage ditch.
Approximately 377 m2 was inaccessible for scanning due to standing water in the drainage ditch.
The standing water in the drainage ditch also precluded scanning a 1-meter radius around 10 systematic soil samples, one judgmental soil sample, and one judgmental sediment sample.
The quality of the data that was collected during FSS was determined to be acceptable and sufficient for determining that the survey unit was suitable for unrestricted release.
Survey Unit 10213B An investigation was performed based on several scan alarms. Two small areas of elevated activity were identified, each 1 ft2 in size. One (1) surface soil sample was taken in each area. Gamma spectroscopy results revealed both samples with concentrations above MDC for Cs-137, and neither sample with concentrations above MDC for Co-60 or Cs-134. Since the OpSOF for both investigation samples were less than one, no further action was necessary.
An additional investigation was performed based on the results of a systematic surface soil sample with an OpSOF exceeding one. An additional 17 investigation samples were taken to bound the area of elevated activity. During the investigation process it was discovered that the rope boundary separating survey unit 10213B with the Class 2 survey unit 10213A, was positioned approximately 2 feet south of the actual boundary defined using GPS. This was discovered during the performance of a surveillance survey in survey unit 10213A. The GPS locations of three (3) of the samples collected during the surveillance survey showed them to be within the boundaries of survey unit 10213B and these samples are included in the FSS. Three (3) of the investigation samples also had activity above an OpSOF of one.
The bounded area was calculated to be approximately 5 m2 based on the GPS coordinates of the bounding samples. The average OpSOF in the bounded area was 1.052.
The average activities for all ROC were below the DCGLEMC values. The conclusion of the investigation was that the survey unit would have passed the EMC, with a final dose for the survey unit of 1.922 mrem/year TEDE.
As a conservative measure, it was decided to remediate the elevated area. Six (6) inches to one (1) foot of soil was removed from the area encompassed by the bounding samples. The 78
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 area remediated was approximately 10 m2. Post-remediation scans showed no areas above the scan MDCR of the instrument. Eight (8) soil samples were taken in the remediated area.
The results of these samples were compared to the subsurface OpDCGLs. No sample result exceeded an OpSOF of one. The remediated excavation was subsequently backfilled using clean fill imported from off-site. As the source term that was prompting the application of the EMC process was removed, the additional dose to the mean of the survey unit BcSOF was not added.
Approximately 42 m2 of open land surface area was inaccessible for scanning due to low lying trees. This area was not in the vicinity of the previously discussed elevated area.
Survey Unit 10213C Investigations were performed based on several scan alarms. Three small areas were identified, each less than 2 ft2 in size. One (1) surface soil sample was taken in each area.
Gamma spectroscopy results revealed all of the samples with concentrations above MDC for Cs-137 and no samples with concentrations above MDC for Co-60 or Cs-134. The OpSOF for the investigation samples were all less than one. No further action was deemed necessary.
Additional surface soil samples were taken where technicians observed elevated count rates near but below the action level. Gamma spectroscopy results revealed all of the samples with concentrations above MDC for Cs-137 and no samples with concentrations above MDC for Co-60 or Cs-134. The OpSOF for these samples were all less than one. No further action was deemed necessary.
An additional investigation was performed when two (2) technicians logged count rates above the alarm set points of their instruments in two (2) locations. The technicians were unaware that this occurred until the downloaded data from the instrument was reviewed. The two (2) locations were re-scanned and the alarms could not be reproduced. No further action was deemed necessary.
One of the sample points randomly selected in the sample plan for a subsurface sample was relocated to the closest adjacent suitable location, which was approximately 3-meters directly south of the original location. The original location was not accessible for the Geoprobe machine to obtain a sample due to the presence of standing water.
Approximately 123 m2 of open land surface area was inaccessible for scanning due to low lying trees and approximately 86 m2 was inaccessible due to standing water and ice.
The standing water and low-lying trees also precluded scanning a 1-meter radius around several sample locations. This did not adversely affect the quality of the data collected during the FSS of this survey unit, which was deemed acceptable.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10214A Investigations were performed following scan alarms. Four (4) areas were identified. One (1) surface and one (1) subsurface soil sample were taken in each elevated area. Two (2) surface and two (2) subsurface soil samples were taken in the elevated area located in row
- 10. Gamma spectroscopy results revealed three (3) samples with activity levels above MDC for Cs-137 and no samples with activity levels above MDC for Co-60 or Cs-134.
Survey Unit 10214B An investigation was performed following a scan alarm. One (1) area was identified. The surface at this location was broken asphalt and soil. One (1) surface and one (1) subsurface soil sample were taken in the elevated area, along with a QC split sample of the surface sample. Gamma spectroscopy results revealed no activity levels above MDC for the ROC in these samples. No further action was taken.
Survey Unit 10214C Investigations were performed following several scan alarms. An area approximately 6 m by 7 m was marked on the west end of the survey unit, in the roadway that consisted of a mix of broken asphalt and soil surfaces. A surface and subsurface soil sample pair were obtained from six (6) locations. Gamma spectroscopy results revealed one (1) sample with activity levels above MDC for Cs-137, one (1) sample with activity levels above MDC for Cs-134, and no samples with activity levels above MDC for Co-60. The OpSOF for all the investigation samples were all less than one. No further action was taken.
Survey Unit 10214D Investigations were performed following several scan alarms. Four (4) areas were identified.
Six (6) surface and six (6) subsurface soil samples were taken in the elevated areas. Gamma spectroscopy results for the investigation samples revealed low levels of Cs-137 activity, and no activity above the MDC for Co-60 or Cs-134. The highest OpSOF for these samples was 0.115. No further action was taken.
A judgmental sample was taken in an area where the instrument recorded the alarm setpoint of the instrument. The instrument did not alarm because the value was incorrectly stored in the instrument. The gamma analysis results for the sample revealed no activity above the MDC for the ROC.
Survey Unit 10214E Investigations were performed following observed scan alarms. Two (2) areas were identified. One (1) surface and one (1) subsurface soil sample were taken in each elevated area. Gamma spectroscopy results revealed one (1) sample with an activity level above MDC for Cs-137 and no samples with activity levels above MDC for Co-60 or Cs-134. The OpSOF for the investigation samples were all less than one. No further action was necessary.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10214F During the FSS of Class 1 open land survey unit 10214F, an investigation was performed following a scan alarm. An elevated area of 1 m2 was identified. One (1) surface soil sample and one (1) subsurface soil sample were taken in the location. Gamma spectroscopy results revealed both of the samples to be less than MDC for Cs-137, Co-60 and Cs-134. No further action was deemed necessary.
Six (6) systematic soil samples were relocated to the closest adjacent suitable location due to the original locations falling on the railroad ballast which is made up of gravel and not soil.
Survey Unit 10220A During the FSS of Class 1 open land survey unit 10220A, two (2) investigations were performed. An investigation was performed following a scan alarm. A small radioactive particle was discovered and captured. Five (5) surface soil samples and a subsurface soil sample were taken following the removal of the particle. Gamma spectroscopy results revealed that activity level for the ROC was less than MDC in all of the investigation samples.
In addition, a second investigation was performed for activity identified at one of the systematic sample locations. This sample had a positive result for Co-60 at 2.16 pCi/g.
Bounding samples were taken to the west, southwest, northwest and directly adjacent to the location of the elevated systematic sample. Gamma spectroscopy results revealed that activity level for the ROC was less than MDC in all of the samples. It was suspected that the activity in the sample was a small radioactive particle. The sample was split and sent to Eberline for HTD analysis. The Eberline results positively indicated Co-60 at a concentration of 5.75 pCi/g, while the on-site lab results showed Co-60 to be less than MDC, which supports the conclusion that the activity was a particle and it was embedded in the soil matrix of the aliquot sent to Eberline. Because the particle was not captured, a conservative estimate of the size of the area was set at 1 m2. The conclusion of the investigation using these parameters was that the survey unit would have passed the EMC, with a final dose for the survey unit of 1.3 mrem/year TEDE. However, use of the EMC was not necessary as the FSS failed due to excessive variability and was performed again with a new set of samples.
Addendum 2 was added to the sample plan for the FSS of survey unit 10220A, which directed that a second set of twenty-three (23) systematic samples be collected to replace the initial sample population of seventeen (17) surface soil samples. This was done because the initial set of seventeen (17) systematic samples had a greater variability, than the value used to calculate the number of samples used in the original survey design.
Survey Unit 10220H During the FSS of Class 1 open land survey unit 10220H, an area of elevated activity above an OpSOF of 1.0 was found in adjacent survey unit 10221D. This activity was found at the 81
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 discharge point of a drain-pipe that runs under the rail line. This water drains to the wetland area in survey units 10220I and 10220H. An additional area was found in the wetland in 10220I that was also above an OpSOF of 1.0. To determine if the activity had spread to the wetlands in 10220H, four (4) judgmental samples were taken in the wetland starting at the boundary with 10220I. Positive Cs-137 was identified in all of the samples, with Co-60 present above the MDC in one (1) of the samples. These samples were all below an OpSOF of 1.0, with the highest at 0.371. No further action was taken.
Survey Unit 10220I During the FSS of Class 1 open land survey unit 10220I, two (2) investigations were performed.
An area of elevated activity was identified by gamma scans. The area of the elevated area was estimated to be approximately 1 ft2. Due to the fact that the area in question was covered with an asphalt like material, a surface soil sample could not be readily obtained. The asphalt like material was removed to a depth of approximately 3 feet. A sample of the asphalt substance was sent to the on-site lab for gamma spectroscopy analysis for a qualitative analysis. This analysis showed that the sample contained concentrations of NORM, but no plant-derived ROC at detectable concentrations. A subsurface soil sample was obtained to a 3-foot depth at the elevated location, along with two (2) additional samples of the asphalt media. Again, the analysis of these samples showed concentrations of NORM, but no plant-derived ROC at detectable concentrations. No further action was deemed necessary.
A second investigation occurred prompted by an area of elevated activity identified in the adjacent survey unit 10221D. This activity was found at the discharge point of a drain pipe that runs under the rail line. This water drains to the wetland area in survey units 10220I and 10220H. To determine if the activity had spread to the wetlands in 10220I, five (5) judgmental samples were taken in the wetland starting at the boundary with 10221D.
Positive concentrations of Cs-137 were identified in all of the samples, and Co-60 was present in positively detected concentrations in two (2) of the judgmental samples. The result of the analysis of one of the judgmental surface soil samples resulted in an OpSOF for the sample of 1.04. Six (6) additional investigation samples were taken to bound the area of elevated activity at an area of 2 m2. The conclusion of the investigation was that the survey unit would have passed the EMC, with a final dose to the survey unit of 1.00 mrem/year.
However, as a conservative measure, the elevated area in this survey unit was remediated, along with an adjoining elevated area in survey unit 10221D. An area of approximately 25 m2 was remediated in the two survey units to a depth of approximately 1 foot. The void was backfilled using clean fill imported from off-site.
Post-remediation scans and sampling showed that the remediation was successful and that the activity was removed. Post-remediation investigation samples were taken at the same locations as the original judgmental samples.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Also, a discrete area in the wetland was not accessible for surface soil scanning due to the presence of standing water.
Survey Unit 10221A During the first attempt at performing FSS in Class 1 open land survey unit 10221A, an investigation was performed based on the analysis of one of the systematic surface soil sample with results exceeding an OpSOF of one. Nine (9) investigation samples were taken to bound the area of elevated activity. Three (3) of the investigation samples also had activity above an OpSOF of one. The elevated area was bounded on all sides except the southwest side which abuts the railroad ballast which consists of gravel and not soil. Therefore, twelve (12) judgmental surface soil samples were taken adjacent to the railroad ballast.
The area of the bounded elevated activity was calculated to be approximately 10 m2 based on the GPS coordinates of the bounding samples. The conclusion of the investigation was that the survey unit would have passed the EMC, with a final dose for the survey unit of 5.795 mrem/year TEDE.
Even though the survey unit passed the sign test and the EMC, and the mean OpSOF did not exceed unity, the initial set of systematic samples had an actual variability which was significantly higher than the variability used for survey design. Consequently, a decision was made to fail the survey unit and, as corrective actions, to remediate the elevated area and obtain a second set of systematic samples under a revised FSS Plan. These samples were collected using a higher estimated variability to increase the sample population density. One foot of soil was removed from the area encompassed by the bounding samples up to the railroad ballast on the southwest side. Post-remediation scans showed no areas above the scan MDCR of the instrument. Five (5) soil samples were taken of the exposed soil in the excavation created by the remediation. The results of these samples were compared to the subsurface OpDCGLs. The maximum OpSOF was 0.672. The remediated excavation was subsequently backfilled using clean fill imported from off-site.
Eight (8) systematic samples were relocated to the closest adjacent suitable location due to the original locations falling on the railroad ballast which is made up of gravel and not soil.
Survey Unit 10221C During the FSS of Class 1 open land survey unit 10221C, an investigation was performed based on the results of gamma scans performed under an RA on the railroad ballast located in survey unit 10221C and the soil areas extending 1-meter beyond the ballast gravel. The RA identified two (2) small areas of elevated activity. A small radioactive particle was identified and captured in the second area. A surface soil sample was taken at the location of each elevated scan and bounding samples were taken in the immediate vicinity (within 1 meter). Gamma spectroscopy results revealed five (5) samples with activity levels above MDC for Cs-137 and no samples with activity levels above MDC for Co-60 and Cs-134.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Since the OpSOF for the investigation samples were all less than one, with a maximum observed OpSOF of 0.300, no further action was deemed necessary.
Three (3) systematic samples were relocated to the closest adjacent suitable location due to the original locations falling on the railroad ballast which is made up of gravel and not soil.
Survey Unit 10221D During the FSS of Class 1 open land survey unit 10221D, an area of elevated activity above an OpSOF of one was discovered after collecting a judgmental surface soil sample in the drainage ditch on the south side of the railroad ballast at the discharge point of a steel culvert running under the ballast. Seventeen (17) investigation surface samples were taken to bound the area of elevated activity. Five (5) of the seventeen (17) investigation samples also showed activity above an OpSOF of one. In addition, the elevated area extended into adjacent survey unit 10220I, where a separate investigation was performed. The area of the bounded elevated area was calculated to be approximately 10 m2 based on the GPS coordinates of the bounding samples. The average OpSOF in the bounded area was 2.628.
The conclusion of the investigation was that the survey unit could have passed the EMC, with a final dose for the survey unit of 5.738 mrem/year TEDE. However, as a conservative measure, the decision was made to remediate the area of elevated activity, including the portion located in survey unit 10220I.
Post-remediation scans showed no areas above the scan MDCR of the instrument. Also, the ballast was scanned and no areas above the scan MDCR of the instrument were detected.
Five (5) additional soil samples were taken in the remediated area. The maximum OpSOF of the post-remediation investigation surface soil samples was 0.743.
Two (2) systematic samples were relocated to the closest adjacent suitable location due to the original locations falling on the railroad ballast which is made up of gravel and not soil.
In addition, a small 1.6 m2 area was not accessible for survey due to standing water.
Survey Unit 12111 During the FSS of Class 1 open land survey unit 12111, three (3) judgmental samples were taken for the FSS. The first sample was taken to investigate an area exhibiting a higher background. This sample was taken at the location in this area which scanning exhibited the highest count rate. Two (2) additional judgmental surface soil samples were taken along the south 20-meter section of the survey unit, which was inaccessible for scans due to standing water. The sample results for all judgmental samples showed activity for the ROC was less than the MDC of the instrument.
Survey Unit 12201C QC scans were performed in four (4) rows at locations of scan alarms. The initial alarm latch readings were confirmed during the QC scans.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 An investigation was performed in an elevated area in rows #19 to #22, in an area bounded as 4m x 5m. The investigation identified the location of the highest reading in row #21 (10,365 cpm). A field gamma spec reading taken at with the Inspector 1000 identified Cs-137. A small piece of concrete was identified and captured. The piece read 50k cpm. Three (3) investigation samples, L1-12201C-FIGS-201-SS, L1-12201C-QIGS-201-SS, and L1-12201C-FIGS-201-SB were collected. These samples showed positive activity for Cs-137, with the highest OpSOF of 0.763.
An investigation was performed at the location of scan alarms in the east end of row #43 (7,913 cpm). A field gamma spec reading taken with the Inspector 1000 identified no plant related nuclides. A QC scan of row #42 confirmed the alarm from the initial scan, and found an additional alarm in the center section (8,374 cpm). Investigation sample L1-12201C-FIGS-202-SS was taken at the location of the center section alarm and L1-12201C-FIGS-203-SS at the east end alarm. No discrete radioactive particle (DRP) was identified during the sampling. These samples showed no activity for the ROC above MDA.
An elevated area was identified on scan surveys that included the center section of rows #52 to #62 and the east section of rows #54 to #60. This area was approximately 200 m2 in size.
The high reading in each row was predominantly in the center section and were latched. A field gamma spec reading taken in each row with the Inspector 1000 identified no plant related nuclides. QC scans were performed in rows #54 and #60. These scans confirmed the readings from the original scans. Investigation samples were taken at the alarms in the east end of row #55 (7,866 cpm), L1-12201C-FIGS-204-SS, and the center of row #58 (9,709 cpm), L1-12201C-FIGS-205-SS. No DRP was identified during the sampling. These samples showed no activity for the ROC above MDA.
Survey Unit 12201D QC scans were performed in survey unit 12201D on 101 m2 of surface area, including the areas at the locations of the scan alarms. The readings of the initial scans were confirmed on the QC scans.
An investigation was performed at the location of a scan alarms at the west end of rows 53 to 58. Six (6) latch readings were recorded. Field gamma spec readings taken with the Inspector 1000 identified no plant related nuclides. A DRP was not identified during the investigation. Two (2) investigation samples, L1-12201D-FIGS-301-SS and L1-12201D-FIGS-302-SS were collected. These samples showed no activity above MDC for the ROC.
An investigation was performed at the location of a scan alarms at the east end of rows 59 and 60. Two (2) latch readings were recorded. Field gamma spec readings taken with the Inspector 1000 identified no plant related nuclides. A DRP was not identified during the investigation. Two (2) investigation samples, L1-12201D-FIGS-303-SS and L1-12201D-QIGS-303-SS were collected. These samples showed no activity above MDC for the ROC.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 12201E An investigation was performed at the location of a scan alarm at the west end of row 70.
One (1) latch reading was recorded. A field gamma spec reading taken with the Inspector 1000 identified no plant related nuclides. A DRP was not identified during the investigation.
Two (2) investigation samples, L1-12201E-FIGS-202-SS and L1-12201E-QIGS-202-SS were collected. These samples showed no activity above MDC for the ROC.
An investigation sample, L1-12201E-FIGS-201-SS, was also taken of the east end of row 58, in an area that showed a higher background, to verify that plant related nuclides were not present. This sample showed no activity above MDC for the ROC.
Survey Unit 12202E During the FSS of Class 1 open land survey unit 12202E, two (2) judgmental surface soil samples were taken to investigate an area exhibiting a higher background. The results of these samples showed no activity above MDC for the ROC. No further action was taken.
Survey Unit 12202F During the FSS of Class 1 open land survey unit 12202F, five (5) judgmental surface soil samples and two (2) judgmental subsurface soil samples were taken to investigate two areas exhibiting higher background. In the first area, two (2) surface soil samples were taken, along with a QC split soil sample and two (2) subsurface soil samples. The results of the analysis of these samples indicated no activity above MDC for the ROC.
In the second area, three (3) surface soil samples were taken. Sample analysis indicated positive activity for Cs-137 in one (1) of the samples at a concentration of 0.208 pCi/g. The analysis of remaining samples indicated no activity above MDC for the ROC. No further action was taken.
Survey Unit 12203A QC scans were performed in survey unit 12203A at the locations of the scan alarms. The initial alarm latch readings were repeated during the QC scans. The results of these readings were used to determine the locations for investigation samples. The following table lists the results for the QC latch mode readings.
One (1) scan alarm was due to small point source of activity:
- 1. Row #16 - surface readings of 8,212 cpm, confirmed by QC reading of 12,174 cpm, identified as a DRP reading 35k cpm.
The DRP listed above was captured and removed from the survey unit. Scans of the soil following the removal showed activity was less than the Action Level. No other DRPs were identified on the original or QC scans.
QC scans were performed in the following areas of the survey unit:
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2
- 1. From rows 7 to 11 in the west 10m section, nine (9) latch values were recorded, which was confirmed on the QC scan. Soil sample L1-12203A-FIGS-015-SS was obtained at the highest of the readings in row #10. The results showed a small positive activity for Cs-137, with an OpSOF of 0.037.
- 2. A latch value was recorded on the east end of row #9, which was confirmed on the QC scan.
- 3. Rows 14 through 20 had eleven (11) latch values recorded. These were individual alarms spaced throughout the rows. QC scans confirmed 8 of the alarms. A DRP was identified and captured in row #16 (east). Soil samples L1-12203A-FIGS-016-SS, L1-12203A-FIGS-017-SS, and L1-12203A-FIGS-018-SS were obtained in rows #16 (east), #17 (west) and #18 (west) at the highest of the readings. The results showed a small positive activity for Cs-137 on one of the samples, with an OpSOF of 0.035.
- 4. Rows 27 through 29 had three (3) latch values recorded. These were individual alarms approximately 10m from the east boundary of the survey unit. QC scans confirmed the alarms. Soil samples L1-12203A-FIGS-19-SS and L1-12203A-FIGS-020-SS were obtained in rows #27 (center) and #29 (east) at the highest of the readings. The results showed a small positive activity for Cs-137 on one of the samples, with an OpSOF of 0.027.
- 5. Rows 33 through 40 had five (5) latch values recorded. These were individual alarms spaced throughout the rows. QC scans confirmed the alarms. Soil samples L1-12203A-FIGS-21-SS and L1-12203A-FIGS-022-SS were obtained in rows #38 (center) and #39 (east) at the highest of the readings. The results showed no activity above MDA for the ROC.
- 6. Rows 44 through 48 had twenty-five (25) latch values recorded. These were located in rows 45 and 46 through all 3-10m sections of these rows. QC scans confirmed most of the alarms. Soil samples L1-12203A-FIGS-23-SS, L1-12203A-FIGS SS, L1-12203A-FIGS-25-SS and L1-12203A-FIGS-026-SS were obtained at the highest of the readings. The results for the samples showed no activity above MDA for the ROC.
- 7. Rows 57 through 69 had eleven (11) latch values recorded in rows 57 and 58. QC scans confirmed four (4) of the alarms. For rows 59 through 67, the entire area was determined to be above the action level. Soil samples L1-12203A-FIGS-27-SS and L1-12203A-FIGS-028-SS were obtained at row 61 (west) and row 66 (east),
respectively. Systematic samples 18, 19, and 20 were also taken in these rows, at rows 65 (west), 63 (center), and 61 (east), respectively. These five samples were spatially distributed throughout the area. The results showed a small positive 87
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 activity for Cs-137 on systematic sample #18, with an OpSOF of 0.035. The results for the other samples showed no activity above MDA for the ROC.
FSS package L1-12203A-F Plan #2 was approved in June of 2021. Subsequently it was decided to increase the sample number in Plan #2 from 17 to 30. FSS package L1-12203A-F Plan #3 was written to direct these 30 systematic samples. It was then decided to increase the required HTD analyses from: 10% of the samples analyzed for the 5 Radionuclides of Concern (ROC) to: 20% of the soil samples collected for the ROC plus all nuclides listed in Table 5-1 of the LTP (Full Suite analysis). Sample plan L1-12203A Plan #4 was written to include this requirement.
Survey Unit 12205E During the FSS of Class 1 open land survey unit 12205E, an investigation was performed following scan alarms in the south end of the survey unit. The area was bounded by scans as being approximately 0.3 m in width by 5 m in length. Four (4) surface soil samples were taken in the bounded area, as well as a split QC soil sample and a subsurface soil sample for the investigation. Gamma spectroscopy results revealed that activity level for the ROC was less than MDC in all of the samples. It was suspected that the higher readings in this area was due to the presence of clay approximately 6-inches below the surface of the sand used to backfill the area. No further action was deemed necessary.
5.4 Evaluation of Number of Sample/Measurement Locations in Survey Units An effective tool utilized to evaluate the number of samples collected in the sampling design is the Retrospective Power Curve generated by VSP, MARSSIM 2000 or COMPASS. The Retrospective Power Curve shows how well the survey design achieved the DQOs. For reporting purposes, all Release Records include a Retrospective Power Curve analysis indicating that the survey design had adequate power to pass the FSS release criteria (i.e., an adequate number of samples were collected).
The Sign Test was selected as the statistical test for all Release Records submitted in this report. This test, performed in accordance with ZS-LT-300-001-004, along with the Retrospective Power Curve demonstrates survey design adequacy. If the data passed the Sign Test and Retrospective Power Curve, the null hypothesis was rejected, and the survey unit was released with no further actions required. For reporting purposes, all survey unit Release Records passed the Sign Test, indicating that the survey design was adequate (i.e.,
an adequate number of samples were collected).
The EMC was not implemented during the FSS of the survey units addressed by this report; however, it was calculated in several survey units (survey units 10207A, 10213B, 10220I, 10221A, 10221D and 12203A). Discrete, elevated areas of contamination were identified in several survey units during FSS. As a conservative measure, it was decided to remediate all activity identified by the surveys as exceeding the OpDCGLs prior to demonstrating 88
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 compliance. In all cases, post-remediation scans showed no areas above the scan MDCR of the instruments and the analysis of all post-remediation samples that were taken indicated OpSOF less than one. In the survey units where the EMC was calculated, as the elevated activity was removed by the remediation, the additional dose to the mean of the survey unit due to the elevated activity was not added. However, the elevated concentration of the systematic sample that exceeded the OpSOF was conservatively used to calculate the mean BcSOF and the resultant assigned dose for the survey unit.
5.5 Comparison of Findings with Derived Concentration Guideline Levels The SOF or unity rule was applied to FSS data in accordance with the guidance provided in Section 2.7 of NUREG-1757, Vol. 2, and the LTP. This was accomplished by calculating a fraction of the OpDCGL for each sample or measurement by dividing the reported concentration by the OpDCGL. If a sample had multiple ROC, then the fraction of the OpDCGL for each ROC was summed to provide an OpSOF for the sample.
Unity rule equivalents were calculated for each measurement result using the inferred concentration for the HTD ROC calculated using the maximum ratios from LTP Chapter 5, Table 5-15. The inferred concentrations were then compared against the applicable OpDCGL to derive an OpSOF for each ROC. The individual OpSOF for each ROC were then summed to derive an OpSOF for the sample. This was the value used to perform the Sign Test. The mean and maximum OpSOF for each open land survey unit addressed in this Phase 4 FSSR is presented in Table 5-1 of this report.
A mean BcSOF was calculated for each ROC by dividing the reported mean concentration for each ROC by the BcDCGL. A BcSOF of one is equivalent to the decision rule, meaning any measurement with a BcSOF of one or greater, would not meet the 25 mrem/year release criteria. The mean BcSOF was multiplied by 25 to establish the dose attributed to soil in a survey unit. A summary of the mean BcSOF and dose contribution for each Phase 4 survey unit is provided in Table 5-2 below.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 5-2, Mean Base Case SOF and Dose Contribution from Soil Survey Mean Dose Survey Mean Dose Description Description Unit BcSOF (mrem/yr) Unit BcSOF (mrem/yr)
Construction Parking 10203A East Training Area 0.010 0.244 10214E 0.008 0.195 Area Construction Parking 10203B East Training Area 0.013 0.321 10214F 0.011 0.278 Area SE Corner of Exclusion 10203C East Training Area 0.010 0.238 10220A 0.014 0.348 Area - Lakeshore SE Corner of Exclusion 10203F East Training Area 0.007 0.181 10220H 0.012 0.307 Area - Lakeshore SE Corner of Exclusion 10204A North Gate Area 0.011 0.283 10220I 0.010 0.244 Area - Lakeshore South of Protected Area -
10204B North Gate Area 0.009 0.235 10221A 0.015 0.379 Inland South of Protected Area -
10204C North Gate Area 0.014 0.361 10221C 0.017 0.427 Inland South of Protected Area -
10204D North Gate Area 0.011 0.279 10221D 0.011 0.286 Inland Station Construction North Half of Unit 2 10206A 0.016 0.392 12104 0.009 0.215 Area Containment Station Construction South Half of Unit 2 10206B 0.012 0.309 12105 0.009 0.216 Area Containment Station Construction North Half of Fuel &
10206C 0.015 0.370 12106 0.008 0.198 Area Auxiliary Buildings Station Construction South Half of Fuel &
10206D 0.018 0.440 12107 0.010 0.246 Area Auxiliary Buildings Station Construction North Half of Unit 1 10206E 0.007 0.180 12108 0.007 0.170 Area Containment South Half of Unit 1 10207A North Warehouse Area 0.035 0.869 12109 0.009 0.236 Containment Yard Between Unit 1 10207B North Warehouse Area 0.010 0.243 12110 0.014 0.340 Containment and Turbine South Yard Area 10207C North Warehouse Area 0.018 0.441 12111 0.008 0.197 Northeast of Gate House North Protected Area 10207D North Warehouse Area 0.013 0.333 12201A 0.009 0.223 Yard North Protected Area 10207E North Warehouse Area 0.011 0.282 12201B 0.008 0.190 Yard North Protected Area 10208A South Warehouse Area 0.012 0.297 12201C 0.004 0.103 Yard North Protected Area 10208B South Warehouse Area 0.012 0.300 12201D 0.004 0.098 Yard North Protected Area 10208C South Warehouse Area 0.012 0.291 12201E 0.003 0.085 Yard Gate House and 10208D South Warehouse Area 0.011 0.272 12202A 0.008 0.206 Southwest Yard Restricted Area South of Gate House and 10209C 0.015 0.382 12202B 0.008 0.202 Gate House Southwest Yard 90
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 5-2 (continued), Mean Base Case SOF and Dose Contribution from Soil Survey Mean Dose Survey Mean Dose Description Description Unit BcSOF (mrem/yr) Unit BcSOF (mrem/yr)
NE Corner of Exclusion Gate House and 10212A 0.012 0.304 12202C 0.010 0.248 Area - Lakeshore Southwest Yard Gate House and 10212B VCC Construction Area 0.010 0.250 12202D 0.010 0.252 Southwest Yard NE Corner of Exclusion Gate House and 10212C 0.015 0.382 12202E 0.006 0.156 Area - Lakeshore Southwest Yard NE Corner of Exclusion Gate House and 10212D 0.021 0.526 12202F 0.010 0.248 Area - Lakeshore Southwest Yard NE Corner of Exclusion Under Service Building 10213A 0.021 0.519 12203A 0.009 0.237 Area and Southeast Yard NE Corner of Exclusion Area Under the Turbine 10213B 0.039 0.968 12205A 0.004 0.104 Area Building NE Corner of Exclusion Area Under the Turbine 10213C 0.025 0.616 12205B 0.006 0.150 Area Building Construction Parking Area Under the Turbine 10214A 0.009 0.230 12205C 0.009 0.220 Area Building Construction Parking Area Under the Turbine 10214B 0.010 0.243 12205D 0.008 0.199 Area Building Construction Parking Area Under the Turbine 10214C 0.009 0.227 12205E 0.008 0.211 Area Building Construction Parking 10214D 0.009 0.232 Area 5.6 Description of ALARA to Achieve Final Activity Levels Section N.1.5 of NUREG-1757, Vol. 2, states that For residual radioactivity in soil at sites that may have unrestricted release, generic analyses show that shipping soil to a low-level waste disposal facility is unlikely to be cost effective for unrestricted release, largely because of the high costs of waste disposal. Therefore, shipping soil to a low-level waste disposal facility generally does not have to be evaluated for unrestricted release. Section 4.4.1 of LTP Chapter 4 presents a simple ALARA analysis for the excavation and disposal of soils as low-level radioactive waste that confirms the statement in Section N.1.5 of NUREG-1757, Vol. 2 that the cost of disposing excavated soil as low-level radioactive waste is clearly greater than the benefit of removing and disposing of soil with residual radioactivity concentrations less than the dose criterion. Since the cost is greater than the benefit, it is not ALARA to excavate and dispose of soils with residual radioactivity concentrations below the DCGL.
Housekeeping and cleanup of survey units was completed prior to turnovers for FSS, and good housekeeping practices were employed during the execution of the FSS. Good housekeeping practices and proper implementation of isolation and control measures in survey units mitigated any potential cross-contamination and ensured that the reported residual activity levels were accurate and final.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 5.7 NRC/Independent Verification Team Findings The Oak Ridge Institute for Science and Education (ORISE) has performed confirmatory surveys in several of the sixty-seven (67) survey units addressed by this Phase 4 FSSR.
ORISE Report 5271-SR-08-0, "Independent Confirmatory Survey Summary And Results For The Remaining Land Areas At The Zion Nuclear Power Station Zion, Illinois (Reference 31) details the results of the FSS confirmatory surveys performed.
6 Summary Final Status Survey is the process used to demonstrate that the ZNPS structures and soils comply with the radiological criteria for unrestricted use specified in 10CFR20.1402. The purpose of the FSS Sample Plan is to describe the methods to be used in planning, designing, conducting, and evaluating the FSS.
The two radiological criteria for unrestricted use specified in 10CFR20.1402 are: 1) the residual radioactivity that is distinguishable from background radiation results in a TEDE to an AMCG that does not exceed 25 mrem/year, including that from groundwater sources of drinking water, and 2) the residual radioactivity has been reduced to levels that are ALARA.
The sixty (60) Class 1 open land survey units, six (6) Class 2 open land survey units and one (1) Class 3 open land survey unit addressed in this Final Report have met the DQOs of the FSS Sample Plans developed and implemented for each. In each survey unit, all identified ROC were used for statistical testing to determine the adequacy of the survey unit for FSS, the sample data passed the Sign Test, the null hypothesis was rejected, and a Retrospective Power Curve showed that adequate power was achieved. Each of the sixty-seven (67) survey units were properly classified. Evaluation of the data for each survey unit shows that none of the ROC concentration values exceeded the OpDCGL or any investigational levels and therefore, in accordance with the LTP Section 5.10, each of the survey units addressed in this Phase 4 FSSR meets the release criterion.
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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 7 References
- 1. Zion Station Restoration Project License Termination Plan
- 2. NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual
- 3. ZS-LT-01, Quality Assurance Project Plan (for Characterization and FSS)
- 4. ZS-LT-300-001-001, Final Status Survey Package Development
- 5. ZS-LT-300-001-003, Isolation and Control for Final Status Survey
- 6. ZS-LT-300-001-004, Final Status Survey Data Assessment
- 7. NUREG-1757, Vol. 2, Consolidated Decommissioning Guidance Characterization, Survey, and Determination of Radiological Criteria
- 8. ZS-LT-300-001-005, Final Status Survey Data Reporting
- 9. Zion Station Historical Site Assessment
- 10. TSD-14-011, Soil Area Factors
- 11. TSD-17-004, Operational Derived Concentration Guideline Levels for Final Status Survey
- 12. TSD-14-028, Radiological Characterization Report
- 13. ZS-RP-108-000-000, Radiological Instrumentation Program
- 14. ZS-RP-108-004-012, Calibration and Initial Set-Up of the 2350-1
- 15. LT-JA-004, FSS Sample Collection
- 16. ZS-LT-100-001-004, Sample Media Preparation
- 17. ZS-WM-131, Chain of Custody Protocol
- 18. ZS-QA-10, Quality Assurance Project Plan
- 19. [Amended] Post-Shutdown Decommissioning Activities Report
- 20. Defueled Safety Analysis Report
- 22. ZS-LT-02, Characterization Survey Plan
- 23. TSD-11-001, Technical Support Document for Potential Radionuclides of Concern During the Decommissioning of the Zion Station
- 24. TSD-13-004, Examination of Cs-137 Global Fallout In Soils At Zion Station
- 25. TSD-14-019, Radionuclides of Concern for Soil and Basement Fill Model Source Terms 93
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2
- 26. ZS-LT-300-001-002, Survey Unit Classification
- 27. ISO 7503-1, Part 1, Evaluation of Surface Contamination, Beta-emitters (maximum beta energy greater than 0.15 MeV) and alpha-emitters
- 28. NUREG-1507, Minimum Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions
- 29. TSD-11-004, Ludlum Model 44-10 Detector Sensitivity
- 30. NRC Inspection Manual, Inspection Procedure 84750, Radioactive Waste Treatment, and Effluent and Environmental Monitoring
- 31. ORISE Report 5271-SR-08-0, "Independent Confirmatory Survey Summary And Results For The Remaining Land Areas At The Zion Nuclear Power Station Zion, Illinois 94
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 8 Appendices A1 FSS Release Record, Survey Unit 10203A A2 FSS Release Record, Survey Unit 10203B A3 FSS Release Record, Survey Unit 10203C A4 FSS Release Record, Survey Unit 10203F A5 FSS Release Record, Survey Unit 10204A A6 FSS Release Record, Survey Unit 10204B A7 FSS Release Record, Survey Unit 10204C A8 FSS Release Record, Survey Unit 10204D A9 FSS Release Record, Survey Unit 10206A A10 FSS Release Record, Survey Unit 10206B A11 FSS Release Record, Survey Unit 10206C A12 FSS Release Record, Survey Unit 10206D A13 FSS Release Record, Survey Unit 10206E A14 FSS Release Record, Survey Unit 10207A A15 FSS Release Record, Survey Unit 10207B A16 FSS Release Record, Survey Unit 10207C A17 FSS Release Record, Survey Unit 10207D A18 FSS Release Record, Survey Unit 10207E A19 FSS Release Record, Survey Unit 10208A A20 FSS Release Record, Survey Unit 10208B A21 FSS Release Record, Survey Unit 10208C A22 FSS Release Record, Survey Unit 10208D A23 FSS Release Record, Survey Unit 10209C A24 FSS Release Record, Survey Unit 10212A A25 FSS Release Record, Survey Unit 10212B A26 FSS Release Record, Survey Unit 10212C A27 FSS Release Record, Survey Unit 10212D A28 FSS Release Record, Survey Unit 10213A A29 FSS Release Record, Survey Unit 10213B A30 FSS Release Record, Survey Unit 10213C A31 FSS Release Record, Survey Unit 10214A A32 FSS Release Record, Survey Unit 10214B A33 FSS Release Record, Survey Unit 10214C A34 FSS Release Record, Survey Unit 10214D A35 FSS Release Record, Survey Unit 10214E A36 FSS Release Record, Survey Unit 10214F A37 FSS Release Record, Survey Unit 10220A A38 FSS Release Record, Survey Unit 10220H A39 FSS Release Record, Survey Unit 10220I 95
FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 A40 FSS Release Record, Survey Unit 10221A A41 FSS Release Record, Survey Unit 10221C A42 FSS Release Record, Survey Unit 10221D A43 FSS Release Record, Survey Unit 12104 A44 FSS Release Record, Survey Unit 12105 A45 FSS Release Record, Survey Unit 12106 A46 FSS Release Record, Survey Unit 12107 A47 FSS Release Record, Survey Unit 12108 A48 FSS Release Record, Survey Unit 12109 A49 FSS Release Record, Survey Unit 12110 A50 FSS Release Record, Survey Unit 12111 A51 FSS Release Record, Survey Unit 12201A A52 FSS Release Record, Survey Unit 12201B A53 FSS Release Record, Survey Unit 12201C A54 FSS Release Record, Survey Unit 12201D A55 FSS Release Record, Survey Unit 12201E A56 FSS Release Record, Survey Unit 12202A A57 FSS Release Record, Survey Unit 12202B A58 FSS Release Record, Survey Unit 12202C A59 FSS Release Record, Survey Unit 12202D A60 FSS Release Record, Survey Unit 12202E A61 FSS Release Record, Survey Unit 12202F A62 FSS Release Record, Survey Unit 12203A A63 FSS Release Record, Survey Unit 12205A A64 FSS Release Record, Survey Unit 12205B A65 FSS Release Record, Survey Unit 12205C A66 FSS Release Record, Survey Unit 12205D A67 FSS Release Record, Survey Unit 12205E 96