ML19295G788

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Revised Final Status Survey (FSS) Report - Phase 2, Turbine Building Basement Survey Unit 06100
ML19295G788
Person / Time
Site: Zion  File:ZionSolutions icon.png
Issue date: 09/01/2019
From: Giza P
ZionSolutions
To:
Office of Nuclear Material Safety and Safeguards
Shared Package
ML19295G627 List:
References
ZS-2019-0090
Download: ML19295G788 (83)
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Text

ZION STATION RESTORATION PROJECT FINAL STATUS SURVEY RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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PREPARED BY / DATE:

2019-09-01 P. Giza, Radiological Engineer REVIEWED BY / DATE:

2019-09-01 R. Massengill, Radiological Engineer APPROVED BY / DATE:

2019-09-01 D. Wojtkowiak, C/LT Manager

FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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TABLE OF CONTENTS

1.

EXECUTIVE

SUMMARY

................................................................................................... 8

2.

CLASSIFICATION BASIS................................................................................................ 11

3.

SURVEY UNIT DESCRIPTION....................................................................................... 15

4.

DATA QUALITY OBJECTIVES (DQO)......................................................................... 20

5.

SURVEY DESIGN.............................................................................................................. 23

6.

SURVEY IMPLEMENTATION........................................................................................ 36

7.

SURVEY RESULTS............................................................................................................ 37

8.

QUALITY CONTROL....................................................................................................... 48

9.

INVESTIGATIONS AND RESULTS............................................................................... 48

10. REMEDIATION AND RESULTS..................................................................................... 49
11. CHANGES FROM THE SURVEY PLAN....................................................................... 49
12. DATA QUALITY ASSESSMENT (DQA)........................................................................ 49
13. ANOMALIES....................................................................................................................... 49
14. COMPLIANCE EQUATION............................................................................................. 50
15. CONCLUSION.................................................................................................................... 52
16. REFERENCES.................................................................................................................... 53
17. ATTACHMENTS................................................................................................................ 54 ATTACHMENT 1 - MAPS.................................................................................................. 55 ATTACHMENT 2 - ISOCS GEOMETRY........................................................................... 60 ATTACHMENT 3 - SIGN TEST.......................................................................................... 71 ATTACHMENT 4 - QC MEASUREMENT ASSESSMENT.................................................... 73 ATTACHMENT 5 - GRAPHICAL PRESENTATIONS........................................................... 77 ATTACHMENT 6 - ISOCS REPORTS............................................................................... 83

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LIST OF TABLES Table 1 - Turbine Building 560 Foot and 570 Foot Elevation Concrete Core Sample Analysis Summary..................................................................................................... 13 Table 2 - Dose Significant Radionuclides and Mixture.......................................................................... 21 Table 3 - Base Case DCGLs (BcDCGLB) for the Turbine Building Basement Survey Unit - LTP Chapter 5, Table 5-3............................................................... 22 Table 4 - Operational DCGLs (OpDCGLB) for the Turbine Building Basement Survey Unit - LTP Chapter 5, Table 5-4............................................................... 23 Table 5 - Surrogate Ratios...................................................................................................................... 24 Table 6 - Surrogate Operational DCGLs for Turbine Building.............................................................. 25 Table 7 - Action Levels for Turbine Building........................................................................................ 25 Table 8 - Adjusted Minimum Number of ISOCS Measurements.......................................................... 26 Table 9 - Random ISOCS Measurement Locations for Turbine Building Structures............................ 27 Table 10 - Judgmental ISOCS Measurement Locations for Turbine Building Structures..................... 28 Table 11 - Random ISOCS Measurement Locations for Unit 1 and Unit 2 Steam Tunnels.................. 29 Table 12 - Judgmental ISOCS Measurement Locations for Unit 1 and Unit 2 Steam Tunnels............. 30 Table 13 - Judgmental ISOCS Measurement Locations for Circulating Water Discharge Tunnels...... 31 Table 14 - Judgmental ISOCS Measurement Locations for Circulating Water Discharge Pipe............ 32 Table 15 - Investigation Levels.............................................................................................................. 34 Table 16 - Synopsis of Survey Design................................................................................................... 35 Table 17 - Summary of ISOCS Results for Random Measurements..................................................... 37 Table 18 - Basic Statistical Properties of Random ISOCS Measurements............................................ 39 Table 19 - Summary of ISOCS Replicate Measurement for QC............................................................ 39 Table 20 - Summary of ISOCS Results for Judgmental Measurements Taken in the Turbine Building Basement and Steam Tunnels.................................................................. 40 Table 21 - Summary of Gamma Spectroscopy Results for Judgmental ISOCS Measurements Taken in Circulating Water Discharge Pipes........................................................................ 41 Table 22 - Basic Statistical Properties of Judgmental ISOCS Measurements in Circulating Water Discharge Pipe.................................................................................... 41 Table 23 - Summary of Results for Judgmental Measurements Taken in the Circulating Water Discharge Tunnels........................................................................ 42 Table 24 - Basic Statistical Properties of Judgmental ISOCS Measurements in Circulating Water Discharge Tunnel................................................................................ 44 Table 25 - Summary of Replicate Measurement Taken in Circulating Water Discharge Tunnel for QC........................................................................ 44 Table 26 - Summary of Final Status Surveys Performed in Ancillary Areas and in Embedded Piping within the Turbine Building Basement.................................................... 46 Table 27 - Surface Survey Units Contributing to the Turbine Building Basement................................ 47

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LIST OF FIGURES Figure 1 - Turbine Building Characterization Concrete Core Locations............................................... 12 Figure 2 - Turbine Building Basement 560 foot Elevation.................................................................... 17 Figure 3 - Turbine Building Basement North......................................................................................... 18 Figure 5 - 510 foot Valve Pit Circulating Water Discharge Pipe........................................................... 32 Figure 6 - Turbine Building Basement Random and Judgmental Measurements.................................. 56 Figure 7 - Unit 1 and Unit 2 Steam Tunnels Random and Judgmental Measurements.......................... 57 Figure 8 - Unit 1 and Unit 2 Circulating Water Discharge Tunnels Judgmental Measurements........... 58 Figure 9 - Unit 1 and Unit 2 Circulating Water Discharge Pipe Judgmental Measurements................. 59 Figure 10 - Quantile Plot for Co-60 Concentrations.............................................................................. 78 Figure 11 - Quantile Plot for Cs-137 Concentrations............................................................................. 79 Figure 12 - Histogram for Co-60 Concentrations................................................................................... 80 Figure 13 - Histogram for Cs-137 Concentrations................................................................................. 81 Figure 14 - Restrospective Power Curve................................................................................................ 82

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LIST OF ACRONYMS AND ABBREVIATIONS ALARA As Low As Reasonably Achievable AMCG Average Member of the Critical Group BcDCGL Base Case Derived Concentration Guideline Level BcSOF Base Case Sum of Fractions BFM Basement Fill Model BIL Basement Inventory Levels DQA Data Quality Assessment DQO Data Quality Objective DCGL Derived Concentration Guideline Level EMC Elevated Measurement Comparison FOV Field of View FSS Final Status Survey HTD Hard-to-Detect IC Insignificant Contributor LTP License Termination Plan LBGR Lower Bound of the Gray Region MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDC Minimum Detectable Concentration MDCR Minimum Detectable Count Rate NaI Sodium Iodide OpDCGL Operational Derived Concentration Guideline Level OpSOF Operational Sum of Fractions ORISE Oak Ridge Institute for Science and Education pCi/m2 activity per unit of area QAPP Quality Assurance Project Plan QC Quality Control RE Radiological Engineer

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ROC Radionuclides of Concern SOF Sum of Fractions TEDE Total Effective Dose Equivalent UBGR Upper Bound of the Gray Region UCL Upper Confidence Level URS Unconditional Release Survey VSP Visual Sample Plan ZNPS Zion Nuclear Power Station ZSRP Zion Station Restoration Project

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1.

EXECUTIVE

SUMMARY

This Final Status Survey (FSS) Release Record for survey unit 06100, Turbine Building, survey unit 09200B, Circulating Water Discharge Tunnels and survey unit 06105A, Unit 1 and Unit 2 Circulating Water Discharge Pipe has been generated for the Zion Station Restoration Project (ZSRP). The release record was developed in accordance with ZionSolutions procedure ZS-LT-300-001-005, Final Status Survey Data Reporting (Reference 1) and satisfies the requirements of Section 5.11 of the Zion Station Restoration Project License Termination Plan (LTP) (Reference 2). This FSS package for basement survey unit 06100, Turbine Building, survey unit 09200B, Circulating Water Discharge Tunnels and survey unit 06105A, Unit 1 and Unit 2 Circulating Water Discharge Pipe and survey unit 6100B Turbine Building Unit 1 and Unit 2 Steam Tunnels, also includes FSS design and FSS results for the following. The stand-alone Release Records for each are attached to this document as Appendices:

  • 06105B Turbine Building 560 foot Embedded Floor Drain Pipe
  • 06209 Unit 1 Steam Tunnel Embedded Floor Drain Pipe
  • 06210 Unit 2 Steam Tunnel Embedded Floor Drain Pipe
  • 06213/14 Unit 1 East and West Valve Houses
  • 06215/16 Unit 2 East and West Valve Houses
  • 06201 Unit 1 Diesel Fuel Oil Storage Tank Room
  • 06202 Unit 2 Diesel Fuel Oil Storage Tank Room
  • 06107 Unit 1 Tendon Buttress Pits
  • 06108 Unit 2 Tendon Buttress Pits
  • 06211 Unit 1 Tendon Tunnel 547 foot Embedded Floor Drain Pipe
  • 06212 Unit 2 Tendon Tunnel 547 foot Embedded Floor Drain Pipe FSS sample plans for each of these survey units were developed in accordance with ZionSolutions procedure ZS-LT-300-001-001, Final Status Survey Package Development (Reference 3), the ZSRP LTP, and guidance from NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (Reference 4). FSS was conducted to demonstrate that the concentrations of residual radioactivity are equal to or below site-specific Derived Concentration Guideline Levels (DCGL) corresponding to the dose criterion in 10 CFR 20.1402.

In accordance with ZSRP LTP Chapter 5, section 5.5.2.1 and Table 5-19, the Turbine Building basement and the Circulating Water Discharge Tunnels are classified as MARSSIM Class 3.

The Circulating Water Intake and Discharge Pipes, the Steam Tunnels, the Tendon Tunnels, the Buttress Pits and the associated embedded piping are integral to the Turbine Building basement and are also classified as MARSSIM Class 3. The Unit 1 and Unit 2 570 foot Diesel Generator rooms were also initially classified as MARSSIM Class 3. However, during the course of

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decommissioning, unpackaged radioactive material was transported through these areas from the Auxiliary Building. Consequently, the Unit 1 and Unit 2 570 foot Diesel Generator rooms were reclassified during decommissioning to MARSSIM Class 1.

The Unit 1 East and West Valve Houses (survey units 06113/14) were also initially classified as Class 3 but during FSS, activity was detected at concentrations greater than 50% of the release criteria. Consequently, these survey units were reclassified as Class 1.

Survey plans were 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.

The Canberra In Situ Object Counting System (ISOCS) was selected as the primary instrument used to perform FSS of the Turbine Building basement, Circulating Water Discharge Tunnels and Circulating Water Discharge Pipe survey units. In accordance with LTP Chapter 5, Table 5-23, the surface area of the complete Turbine Building Basement survey unit (including all ancillary areas) was determined to be 27,135 m2.

In accordance with LTP Chapter 5, Table 5-19, the minimum number of measurements necessary in the Turbine Building basement (which includes the area of the Steam Tunnels, the Diesel Generator Rooms, the Tendon Tunnels and the Valve Houses) and inside the Circulating Water Discharge Tunnels was fourteen (14). In addition, four (4) judgmental measurements were acquired in the Circulating Water Discharge Pipe. During FSS, a total of twenty-eight (28) random ISOCS measurements and 173 judgmental ISOCS measurements were taken on structural surfaces in the Turbine Building basement. Additionally, 327 random measurements were taken during FSS within embedded pipe systems that remain in the Turbine Building basement.

In accordance with ZionSolutions TSD 14-016, Description of Embedded Piping, Penetrations, and Buried Pipe to Remain in Zion End State (Reference 5), there were 11 penetrations (T91, T92, T93, T94, T96, T97, T98, T99, T100, T101 and T104) that accessed the exterior C wall of the Turbine Building basement (east wall) between the 585 foot and the 586 foot elevation. The pipes were all removed in April of 2017 during decommissioning, and the penetration openings in the Turbine Building east and west walls were grouted as required by LTP Chapter 6, section 6.6.1.

Penetrations also interfaced between the Turbine Building and the Auxiliary Building, primarily through the G wall but also through the north and south walls into the Unit 1 and Unit 2 Steam Tunnels, as well as both Unit 1 and Unit 2 Containments, through the Unit 1 and Unit 2 Main Steam Valve Houses. LTP Chapter 6, section 6.4.5 states, The dose from penetrations is summed with the dose from the wall and floor surfaces of both basements that the penetration interface. The FSS of the Turbine Building penetrations that interface with the Auxiliary Building is presented in the Release Record for the Auxiliary Building penetrations and, the FSS of the Turbine Building penetrations that interface with the Unit 1 and Unit 2

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Containments are presented in the Release Records for the Unit 1 and Unit 2 Containment penetrations. The FSS design employed the Operational DCGLs (OpDCGL) for the Auxiliary Building and Containment Penetrations as they were the most limiting. The resultant mean dose from interfacing penetrations was added to the Turbine Building dose to ensure compliance with the LTP.

When this survey commenced in March of 2016, it was performed at risk in accordance with the initial version of the LTP, which was not approved. The survey design for all four (4) survey units in this document utilized Basement Inventory Levels (BIL) as the OpDCGLs had not yet been developed. The initial analysis of the FSS data was directly compared against the BILs to determine the Sum of Fractions (SOF) of individual measurements and to derive the values used for the Sign Test. In addition, other commitments from Revision 2 of the LTP, such as the requirement to acquire concrete core samples for Hard-to-Detect (HTD)

Radionuclides of Concern (ROC) analysis were not required at the time the surveys were performed. When compared against the BILs, all measurements taken for the FSS of these three (3) survey units were less than a SOF of 0.5 and decommissioning decisions were made based upon those results. However, for this Release Record, the measurement results taken in 2016 were compared against the OpDCGLs from the approved Revision 2 of the LTP. As the OpDCGLs are significantly more conservative than the BILs, several measurements exceeded a SOF (OpSOF) of 0.5 when compared against the OpDCGLs and several measurements exceeded an OpSOF of one. No measurements exceeded the Base Case DCGLs (BcDCGL).

In these cases, no investigations were performed as required by LTP Chapter 5, section 5.6.4.6 and, no assessment was made to determine if reclassification was appropriate as required by LTP Chapter 5, section 5.6.4.6.1. By the time this discrepancy was identified, the Turbine Building basement void had been completely backfilled and additional investigations were not possible. In addition, it should also be noted that with the exception of the two (2) measurements taken in the Unit 2 Discharge Tunnel (BcSOF of 0.941 and 0.686), all measurements were less than a SOF (BcSOF) of 0.5 when compared against the BcDCGLs.

Despite these differences in LTP Rev. 0 vs. Rev. 2 compliance, sufficient measurements were acquired to adequately quantify the radiological source term that remains in the Turbine Building footprint, thus, the dose assigned is representative and conservative. Upon discovery of these differences during preparation for this submittal, a Condition Report (ES-ZION-CR-2019-0020) was initiated to document the issue and any corrective actions.

Of the twenty-eight (28) random and 173 judgmental measurements obtained in the Turbine Building, two (2) judgmental ISOCS measurements taken in sumps exceeded an OpSOF of 0.5.

One (1) random measurement taken in the Unit 1 Steam Tunnel and two judgmental ISOCS measurements taken in the Unit 2 Circulating Water Discharge Tunnel exceeded an OpSOF of one.

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The mean OpSOF for the Turbine Building basement was 0.245 with a maximum OpSOF of 1.346. When compared against the BcDCGL for the Turbine Building, the mean BcSOF (area-weighted adjusted for the elevated measurement) for the Turbine Building basement was 0.021, which results in the dose calculated for this survey unit to be 0.523 mrem/yr.

The mean OpSOF for the Circulating Water Discharge Pipe was 0.146 with a maximum OpSOF of 0.417. When compared against the BcDCGLB, the mean BcSOF for the Circulating Water Discharge Pipe was 0.012, which results in the dose calculated for this survey unit to be 0.310 mrem/yr.

The mean OpSOF for the Circulating Water Discharge Tunnels was 0.285 with a maximum OpSOF of 2.252. When compared against the BcDCGLB, the mean BcSOF for the Circulating Water Discharge Tunnels (area-weighted adjusted for the 2 elevated measurements) was 0.127, which results in the dose calculated for this survey unit to be 3.180 mrem/yr.

In accordance with LTP Chapter 6, section 6.6.8, the activity in the Circulating Water Intake Pipes, Circulating Water Discharge Tunnels, Circulating Water Discharge Pipes, Buttress Pits/Tendon Tunnels, Diesel Generator Rooms and Valve Houses are included with Turbine Building through the DCGL calculation. The activity in the Circulating Water Intake Pipe is conservatively assumed to be part of the Turbine Building and the Crib House/Forebay survey units simultaneously. Consequently, the area-weighted mean of the measurements in these survey units are added to the mean (BcSOF) of the Turbine Building results. The area-weighted adjusted mean BcSOF for the Turbine Building is 0.037, which equates to a dose of 0.937 mrem/yr.

It should be noted that prior to backfill, a confirmatory survey of the Turbine Building basement was performed by Oak Ridge Institute for Science and Education (ORISE) with no findings.

2.

CLASSIFICATION BASIS Survey Units 06100, 09200 and 06105A were classified in accordance with ZionSolutions procedure ZS-LT-300-001-002, Survey Unit Classification (Reference 6). The Turbine Building and all systems within the Turbine Building were initially classified as a Class 2 structure by the Zion Station Historical Site Assessment (HSA) (Reference 7).

In November of 2012, Site Characterization of the Turbine Building commenced with the acquisition of a series of concrete core samples that were taken in the 560 foot elevation Turbine Building concrete floor as well as the 570 foot elevation Steam Tunnel concrete floors.

The locations where the core samples were taken are illustrated in Figure 1.

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Figure 1 - Turbine Building Characterization Concrete Core Locations A total of 10 concrete core samples were collected, 3 in the Turbine Building 560 foot elevation floor, 5 in the Unit 1 Steam Tunnel floor and 2 in the Unit 2 Steam Tunnel floor. The locations selected were biased toward locations where physical or observed radiological measurements indicated the presence of fixed and/or volumetric contamination of the concrete media. When possible, locations were determined based upon elevated observed contact dose rates or count rates. In addition, visual observations of floor and wall surfaces were used to identify potential locations of surface contamination, such as discoloration or standing water.

The goal was to identify, to the extent possible, the locations that exhibited the highest potential of representing the worst case radiological condition for concrete in each survey unit. A summary of the gamma spectroscopy results for the concrete cores obtained from the Turbine Building 560 foot elevation and the 570 foot elevation Steam Tunnels are provided in Table 1.

Cs-137 was the only plant-derived gamma emitting radionuclide identified. Concentrations for Co-60 were less than the Minimum Detectable Concentration (MDC) for all samples from the Turbine Building and the Steam Tunnels.

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Table 1 - Turbine Building 560 Foot and 570 Foot Elevation Concrete Core Sample Analysis Summary Location Sample ID Core Depth (inches)

Co-60 Cs-137 Surface Activity (1)(3)

Avg.

Subsurface Activity (2)(3)

Surface Activity (1)(3)

Avg.

Subsurface Activity (2)(3)

(pCi/g)

(pCi/g)

(pCi/g)

(pCi/g)

TB 560 el. North @ Grid F8 B206104-CJFCCV-001 5.5 1.14E-01 8.57E-02 1.27E-01 1.30E-01 TB 560 el. North @ Grid F11 B206104-CJFCCV-002 5.0 2.11E-01 1.07E-01 1.65E+00 1.76E-01 TB 560 el. North @ Grid F12 B206104-CJFCCV-003 4.0 2.73E-01 1.10E-01 4.67E+00 1.37E+00 Unit 1 Steam Tunnel @ Grid L32 B206207-CJFCCV-001 2.0 1.04E-01 1.18E-01 4.67E+00 2.98E+00 Unit 1 Steam Tunnel @ Grid K31 B206207-CJFCCV-002 2.0 1.30E-01 6.86E-02 4.52E+01 3.02E+00 Unit 1 Steam Tunnel@ Grid M32 B206207-CJFCCV-003 2.0 1.06E-01 9.61E-02 1.49E+01 1.03E+00 Unit 1 Steam Tunnel o/s West Valve Room B206207-CJFCCV-004 2.0 1.66E-01 7.57E-02 3.97E+01 2.44E+00 Unit 1 Steam Tunnel @ End of Tunnel B206207-CJFCCV-005 1.5 6.56E-02 1.22E-01 1.74E+01 1.70E+00 Unit 2 Steam Tunnel o/s West Valve Room B206208-CJFCCV-001 2.0 1.50E-01 1.17E-01 6.72E+00 5.95E-01 Unit 2 Steam Tunnel o/s West Valve Room B206208-CJFCCV-002 5.0 1.35E-01 8.93E-02 1.86E+01 1.97E-01 (1) Represents surface activity of floor following removal of loose contamination (2) Represents average of activity over entire depth of core sample minus the surface activity (3) Italicized values indicate MDC value.

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Analyses of the concrete core samples taken from the Turbine Building 560 foot elevation show the presence of Cs-137 at concentrations greater than the MDC of the instrument at 2 of the 3 sample locations, and only in the first half-inch of concrete. Observed Cs-137 concentrations ranged from 1.65 pCi/g to 4.67 pCi/g. At depths greater than 1 half-inch, concentrations for Cs-137 were less than MDC. In the Steam Tunnels, Cs-137 concentrations in the first half-inch of concrete ranged from 4.67 pCi/g to 45.2 pCi/g in Unit 1 and 6.72 pCi/g to 18.6 pCi/g in Unit 2. At depths greater than 1 half-inch, concentrations for Cs-137 were less than the MDC of the instrument used.

Between March 21, 2013, and March 27, 2013, additional characterization was performed in the Turbine Building. All accessible surfaces of the 560 foot elevation floor in the Turbine Building were scanned using a Ludlum Model 43-37 floor monitor. The average background of the instrument was 900 cpm. The alarm set-point was set at the observed background plus the Minimum Detectable Count Rate (MDCR) for the instrument. The mean observed count rate was 1,493 cpm with a maximum observed count rate of 3,922 cpm. Three (3) instrument alarms were observed, primarily around a posted radiological area adjacent to the elevator.

In accordance with the Basement Fill Model (BFM), the classification for the Turbine Building, Circulating Water Discharge Pipe and Circulating Water Discharge Tunnel survey units were changed from their original classification of Class 2 to Class 3 consistent with Section 5.5.2.1 of the LTP Chapter 5. The survey units and classifications designated for structures below 588 foot elevation from the HSA that were presented in LTP Chapter 2, Table 2-2 were based on screening values and source term assumptions that are significantly different from the BFM and were therefore not applicable. Process knowledge and the results of past radiological surveys and site characterization indicated that the probability of residual radioactivity in these FSS units exceeding 50% of the allowable inventory for the Turbine Building was very low.

During plant operations, the Circulating Water Discharge Tunnels were the main authorized effluent release pathway for the discharge of treated and filtered radioactive liquid effluent to Lake Michigan. The liquid effluent release pathway was monitored and the results presented in the annual Radiological Environmental Monitoring Program (REMP) report in accordance with the Off-site Dose Calculation Manual (ODCM). During decommissioning, the Unit 2 Circulating Water Discharge Tunnel was used as the authorized effluent release pathway from July 2013 to October 2015.

The FSS units for the basement of the Turbine Building, the Circulating Water Discharge Pipe and the Circulating Water Discharge Tunnel were designated as Class 3 as defined in MARSSIM, section 2.2 in that the FSS units were not expected to contain any residual radioactivity, or expected to contain levels of residual radioactivity at a small fraction of the DCGLs, based on site operating history and previous radiation surveys. The Turbine Building basement FSS unit would be subjected to an areal coverage commensurate with the guidance pertaining to Class 3 scan coverage as presented in MARSSIM, Table 5.9, which states that the

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scan coverage guidance is judgmental. In this context, judgmental areal coverage was defined as sufficient ISOCS measurements to ensure that at least 1% of the surface area in the survey unit was subjected to FSS.

A FSS Engineer performed a visual inspection and walk-down of the survey unit on April 14, 2016, prior to performing FSS. The purpose of the walk-down was to assess the physical condition of the survey unit, evaluate access points and travel paths and identify potentially hazardous conditions. A final classification assessment was performed in accordance with procedure ZS-LT-300-001-002 as part of the survey design for FSS.

Based upon completion of Survey Unit Classification Basis for final classification, which included a review of the historical information, the results of the Characterization Survey data and completion of a final Survey Unit Classification Worksheet, it was concluded that there was a low probability for the presence of residual radioactivity at concentrations greater than 50% of the allowable inventory, justifying a final survey unit classification of Class 3 for survey units 06100, 09200 and 06105A.

3.

SURVEY UNIT DESCRIPTION The Turbine Building basement survey unit is an impacted Class 3 basement FSS unit. A basement FSS unit is comprised of the combined internal wall and floor surfaces of each remaining building basement below the 588 foot elevation following demolition. The Turbine Building footprint is located within Class 1 open land survey units 12205A, 12205B, 12205C, 12205D and 12205E.

The Turbine Building housed the steam turbines and generators for both reactor units as well as secondary steam systems, circulating water systems, lubrication and fuel oil systems and emergency diesel generators. The internal structures that supported the Condensers, Turbine and Generators are solid concrete below the 588 foot elevation. The Circulating Water Intake and Discharge pipes are embedded in concrete above the 560 foot elevation. The floors of the Unit 1 and Unit 2 Steam Tunnels are at the 570 foot elevation and the floors of the Unit 1 and Unit 2 Diesel Generator Oil Storage rooms are at the 567 foot elevation. The Turbine Building sits on top of the Circulating Water Discharge Tunnels. The floor of the Unit 1 and Unit 2 Turbine Building basement is at the 560 foot elevation and has a Common Area between them.

The Unit 1 and 2 areas are mirror images of each other.

The Unit 1 and Unit 2 Circulating Water Discharge Pipe and Discharge Tunnels provided for the discharge of cooling water, primarily from the Main Condensers but also from ancillary cooling systems, to Lake Michigan. The Circulating Water Discharge Tunnels were also the main authorized effluent release path to Lake Michigan for the release of treated and filtered radioactive liquid effluent. The tunnels run under the Turbine Building where two (2) 12 foot diameter Circulating Water Discharge pipes open into the tunnels from above. The tunnels dip

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down under the Circulating Water Intake Pipes and then up again to the Valve House where they connect to the 14 foot diameter tunnels to Lake Michigan.

Large component removal in the Turbine Building was completed in 2015. Initial component removal included the dismantlement and removal of most of the large components, including the turbines, generator, moisture separator reheaters, feedwater heaters and coolers. In parallel with this effort, surveys were performed for the unconditional release of materials, equipment and structural surfaces throughout the building. Unconditional Release Surveys (URS) were performed in accordance with ZS-LT-400-001-001, Unconditional Release of Material, Equipment and Secondary Structures (Reference 8).

All systems and materials that were identified by radiological survey as contaminated with detectable plant-derived radioactive material were removed and properly disposed of as radioactive waste. The remaining structure and materials in the Turbine Building were surveyed to demonstrate compliance with the unconditional release criteria. All remaining commodities were removed from the Turbine Building basement, with the exception of the underground Circulating Water pipe, Circulating Water Discharge Tunnels and buried Service Water pipe running between the Crib House location and the Auxiliary Building beneath the Turbine Building concrete floor.

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Figure 2 - Turbine Building Basement 560 foot Elevation

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Figure 3 - Turbine Building Basement North

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The Turbine Building structure was demolished to a depth of 3 feet below grade in accordance with the requirements of the Asset Sale Agreement. The Circulating Water Intake Piping, Circulating Water Discharge Pipe were filled with grout and the Intake/Discharge pipe and Discharge Tunnels were abandoned in place. Following the performance of FSS (as detailed in this Release Record) and a confirmatory survey by ORISE, the Turbine Building void was backfilled to the 588 foot elevation using clean concrete debris and clean fill from off-site.

Figure 4 - Turbine Building Demolition

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4.

DATA QUALITY OBJECTIVES (DQO)

Final Status Survey planning and design hinges on coherence with the Data Quality Objective (DQO) process to ensure, through compliance with explicitly defined inputs and boundaries, that the primary objective of the survey is satisfied. The DQO process is described in the ZSRP LTP in accordance with MARSSIM. The appropriate design for a given survey was developed using the DQO process as outlined in Appendix D of MARSSIM.

The DQO process incorporated hypothesis testing and probabilistic sampling distributions to control decision errors during data analysis. Hypothesis testing is a process based on the scientific method that compares a baseline condition to an alternate condition. The baseline condition is technically known as the null hypothesis. Hypothesis testing rests on the premise that the null hypothesis is true and that sufficient evidence must be provided for rejection. In designing the survey plan, the underlying assumption, or null hypothesis was that residual activity in the survey unit exceeded the release criteria. Rejection of the null hypothesis would indicate that residual activity within the survey unit does not exceed the release criteria.

Therefore, the survey unit would satisfy the primary objective of the FSS sample plan.

The primary objective of the FSS sample plan is to demonstrate that the level of residual radioactivity in survey units 06100, 09200 and 06105A did not exceed the release criteria specified in the LTP and that the potential dose from residual radioactivity is As Low As Reasonably Achievable (ALARA).

ZionSolutions TSD 11-001, Technical Support Document for Potential Radionuclides of Concern During the Decommissioning of the Zion Station (Reference 9) established the basis for an initial suite of potential ROC for the decommissioning of the Zion Nuclear Power Station (ZNPS). LTP Chapter 2 provides detailed characterization data that described contamination levels in the basements. The survey data for basements is based on core samples obtained at biased locations with elevated contact dose rates and/or evidence of leaks/spills and analyzed for the presence of plant-derived radionuclides. ZionSolutions TSD 14-019, Radionuclides of Concern for Soil and Basement Fill Model Source Terms (Reference 10) evaluates the results of the concrete core analysis data from the Containments and Auxiliary Building and refines the initial suite of potential ROC by evaluating the dose significance of each radionuclide.

LTP Chapter 6, section 6.5.2 discusses the process used to derive the ROC for the decommissioning of ZNPS, including the elimination of insignificant dose contributors (IC) from the initial suite. Based upon the analysis of the mixture, it was determined that Co-60, Ni-63, Sr-90, Cs-134 and Cs-137 accounted for 99.5% of all dose in the non-activated contaminated concrete mixes.

Due to absence of significant source term in the Turbine Building, the suite of ROC and radionuclide mixture derived for the Auxiliary Building concrete was considered as a

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reasonable conservative mixture to apply to the Turbine Building for FSS planning and implementation. Table 2 reproduces the ROC from LTP Chapter 5, Table 5-2.

Table 2 - Dose Significant Radionuclides and Mixture Radionuclide Auxiliary Building

% of Total Activity (normalized)(1)

Co-60 0.92%

Ni-63 23.71%

Sr-90 0.05%

Cs-134 0.01%

Cs-137 75.32%

(1) Based on maximum percent of total activity from Table 20 of TSD 14-019, normalized to one for the dose significant radionuclides.

A fundamental precursor to survey design is to establish a relationship between the release criteria and some measurable quantity. This is done through the development of DCGLs. The DCGLs represent average levels of radioactivity above background levels and are presented in terms of surface or mass activity concentrations. Chapter 6 of the LTP describes in detail the modeling used to develop the DCGLs for structures.

The End State basements are comprised of steel and/or concrete structures which were covered by at least three (3) feet of clean soil and physically altered to a condition which would not realistically allow the remaining structures, if excavated, to be occupied. The exposure pathways in the BFM are associated with residual radioactivity in floors and walls that is released through leaching into water contained in the interstitial spaces of the fill material. The BFM assumes that the inventory of residual radioactivity in a given building is released either instantly or over time by diffusion, depending on whether the activity is surficial or volumetric, respectively. The activity released into the fill water will adsorb onto the clean fill, as a function of the radionuclide-specific distribution coefficients, resulting in equilibrium concentrations between the fill and the water. Consequently, the only potential exposure pathways after backfill, assuming the as-left geometry, are associated with the residual radioactivity in the water contained in the fill.

The final outputs of the BFM are the Basement DCGLs which are calculated using the BFM Groundwater (GW) and BFM Drilling Spoils Dose Factors. DCGLs are calculated separately for the GW and Drilling Spoils scenarios and for the summation of both scenarios. The summation DCGL is designated as the BcDCGL and is used during FSS to demonstrate compliance (analogous to the DCGLW as defined in MARSSIM). The BcDCGLs are

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radionuclide-specific concentrations that represent the 10 CFR 20.1402 dose criterion of 25 mrem/yr and are calculated for each ROC and each backfilled basement.

When applied to structures, the DCGLs are expressed in units of activity per unit of area (pCi/m2). The unity rule is applied when there is more than one ROC. The measurement results for each singular ROC present in the mixture are compared against their respective DCGL to derive a dose fraction.

The BcDCGLs for the unrestricted release of the Turbine Building basement survey unit are provided in Table 3. The IC dose percentage of 5% was used to adjust the Turbine Building basement DCGLs to account for the dose from the eliminated IC radionuclides.

Table 3 - Base Case DCGLs (BcDCGLB) for the Turbine Building Basement - LTP Chapter 5, Table 5-3 Radionuclide Turbine Building Floors and Walls (pCi/m2)

Co-60 7.03E+07 Ni-63 2.18E+09 Sr-90 7.74E+05 Cs-134 1.59E+07 Cs-137 2.11E+07 Each radionuclide-specific BcDCGL is equivalent to the level of residual radioactivity (above background levels) that could, when considered independently, result in a Total Effective Dose Equivalent (TEDE) of 25 mrem/yr to an Average Member of the Critical Group (AMCG). To ensure that the summation of dose from each source term is 25 mrem/yr or less after all FSS is completed, the BcDCGLs are reduced based on an expected, or a priori, fraction of the 25 mrem/yr dose limit from each source term. The reduced DCGLs, or Operational DCGLs can be related to the BcDCGLs as an expected fraction of dose based on an a priori assessment of what the expected dose should be based on the results of site characterization, process knowledge and the extent of planned remediation. The OpDCGL is then used as the DCGL for the FSS design of the survey unit (calculation of surrogate DCGLs, investigations levels, etc.).

Details of the OpDCGLs derived for each dose component and the basis for the applied a priori dose fractions are provided in TSD 17-004, Operational Derived Concentration Guideline Levels for Final Status Survey (Reference 11).

The OpDCGLs for the unrestricted release of the Turbine Building basement survey unit are provided in Table 4.

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Table 4 - Operational DCGLs (OpDCGLB) for the Turbine Building Basement - LTP Chapter 5, Table 5-4 Radionuclide Turbine Building Floors and Walls Circulating Water Discharge Pipe (pCi/m2)

Circulating Water Discharge Tunnel (pCi/m2)

Co-60 5.98E+06 2.94E+07 Ni-63 1.85E+08 9.11E+08 Sr-90 6.58E+04 3.24E+05 Cs-134 1.35E+06 6.65E+06 Cs-137 1.79E+06 8.82E+06 Instrument DQOs included a verification of the ability of the survey instrument to detect the radiation(s) of interest relative to the OpDCGL. The Canberra ISOCS was selected as the primary instrument used to perform FSS of basement surfaces. Survey instrument response checks were required prior to issuance and after the instrument had been used. Control and accountability of survey instruments was required to assure the quality and prevent the loss of data.

As part of the DQOs applied to laboratory processes, analysis results were reported as actual calculated results. The actual recorded value was used as the recorded FSS result for measurement and/or sample values that are less than MDC. Negative values were recorded as zero. For radionuclides less than MDC, the value representing the highest abundance was selected. Results were not reported as less than MDC. Sample report summaries included unique sample identification, analytical method, radionuclide, result, uncertainty, laboratory data qualifiers, units, and the observed MDC.

In accordance with the LTP, for laboratory analysis, MDCs less than 10% of the OpDCGL were preferable while MDCs up to 50% of the OpDCGL were acceptable. The maximum acceptable MDC for measurements obtained using field instruments was 50% of the applicable OpDCGL.

5.

SURVEY DESIGN 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.

During FSS, concentrations for HTD ROC Ni-63 and Sr-90 were inferred using a surrogate approach. Cs-137 is the principle surrogate radionuclide for Sr-90 and Co-60 is the principle

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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 TSD 14-019 and are presented in Table 5. The maximum ratios were used in the surrogate calculations during this FSS. Equations 1 through 3 show the results of the calculations. The results of the surrogate calculations are listed in Table 6.

Table 5 - Surrogate Ratios Ratios Auxiliary Building Mean Max 95%UCL Ni-63/Co-60 44.143 180.450 154.632 Sr-90/Cs-137 0.001 0.002 0.002 The equation for calculating a surrogate DCGL is as follows:

Equation 1

=

1

1

+

2 2+

3 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 4 and the maximum ratios from Table 5, the following surrogate calculations were performed:

Equation 2 (Cs-137 Surrogate OpDCGL)

(137) =

1

1 1.79+ 06(137)+

0.002 6.58+ 04(90)

= 1.70+ 06 /2 Equation 3 (Co-60 Surrogate OpDCGL)

(60) =

1

1 5.98+ 06(060)+

180.45 1.85+ 08(63)

= 8.75+ 05 /2

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Table 6 - Surrogate Operational DCGLs for Turbine Building Radionuclide Turbine Building Floors and Walls, Circulating Water Discharge Pipe Circ. Water Discharge Tunnel pCi/m2 pCi/m2 Co-60 8.75E+05 4.31E+06 Cs-137 1.70E+06 8.36E+06 The action level for investigation in a Class 3 basement structure survey unit is 50% of the OpDCGL. The action levels for survey units 06100, 09200 and 06105A are presented in Table 7.

Table 7 - Action Levels for Turbine Building Radionuclide Action Levels Turbine Building Floors and Walls, Circulating Water Discharge Pipe Circ. Water Discharge Tunnel (pCi/m2)

(pCi/m2)

Co-60 4.38E+05 2.16E+06 Cs-134 6.75E+05 3.33E+06 Cs-137 8.49E+05 4.18E+06 The Sign Test was selected as the non-parametric statistical test. The use of the Sign Test did not require the selection or use of a background reference area, which simplified survey design and implementation. This approach was conservative since it included background Cs-137 as part of the sample set.

The Elevated Measurement Comparison (EMC) did not apply to this survey unit. At the ZSRP, EMC only applies to soils as all other media (structural surfaces, embedded pipe, buried pipe and penetrations) will be remediated to their applicable BcDCGL. In addition, survey units 06100, 09200 and 06105A were Class 3 basement survey units and discrete, elevated areas of contamination were not expected.

Sample size determination for FSS of basement surface survey units is addressed in LTP Chapter 5, section 5.5.2.2. To ensure that the number of ISOCS measurements based on the necessary areal coverage in a basement surface FSS unit was sufficient to satisfy a statistically based sample design, a calculation was performed to determine sample size. If the sample size based on the statistical design required more ISOCS measurements than the number of ISOCS

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measurement required by the areal coverage, then the number of ISOCS measurements was adjusted to meet the larger sample size.

Following the guidance in MARSSIM, the Type I decision error that was used for this calculation was set at 0.05 and the Type II decision error was set at 0.05. The Upper Bound of the Gray Region (UBGR) was set at the OpDCGLB. The Lower Bound of the Gray Region (LBGR) was set at the expected fraction of the OpDCGLB. The expected fraction of the OpDCGLB in a Class 3 FSS basement unit was set at 1%. The standard deviation of the concrete core samples taken in the Turbine Building was used for sigma ().

The relative shift (/) was calculated as discussed in LTP Chapter 5, section 5.6.4.1.6. The relative shift (/) for the survey unit data set is defined as shift (), which is the UBGR, or the OpDCGLB (OpSOF of 1) minus the LBGR (OpSOF of 0.01), divided by sigma (), which is the standard deviation of the data set used for survey design. The optimal value for / should range between 1 and 3. The largest value the / can have is 3. If the / exceeds 3, then the value of 3 will be used for /. The / for survey unit 06100, based on standard deviation of 15.66 for Cs-137 resulted in a / that was greater than 3. Consequently, a value of 3 was used as the adjusted relative shift (/). From Table 5-5 of MARSSIM, the required number of measurements (N) for use with the Sign Test, using a value of 0.05 for the Type I and Type II decision errors, is 14 measurements for a / value of 3. Consequently, the number of ISOCS measurements in Turbine Building basement surface FSS unit was adjusted to meet the larger sample size. Table 8 presents the Turbine Building basement surface FSS units from LTP Chapter 5, Table 5-19 and the adjusted number of ISOCS measurements required.

Table 8 - Adjusted Minimum Number of ISOCS Measurements FSS Unit Classification Required Areal Coverage Adjusted # of ISOCS Measurements Adjusted Areal Coverage Adjusted Areal Coverage (m2)

(FOV-28 m2)

(m2)

(% of Area)

Turbine Building Basement Class 3 149 14 392 3%

Circulating Water Discharge Tunnels Class 3 49 14 392 8%

A Retrospective Power Curve was generated using MARSSIM Power 2000, a software package developed to support the decommissioning license termination rule (10CFR20, Subpart E). The result of the MARSSIM Power 2000 program computer run showed adequate power for the survey design (see Attachment 5). The survey design specified 14 ISOCS measurements for non-parametric statistical testing.

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As the survey unit was classified as Class 3, measurement locations were selected at random.

The random locations of the ISOCS measurements were selected using Visual Sample Plan (VSP), in accordance with ZS-LT-300-001-001. Input parameters included use of a grid layout and the random sampling tool set with a predetermined number (14) of measurement points.

Measurement locations for the ISOCS measurements taken for survey design are listed with the grid coordinates, based on a local origin selected by the survey designer, in Table 9. A map of the random ISOCS measurement locations for the Turbine Building basement is provided in Figure 6 in Attachment 1.

Table 9 - Random ISOCS Measurement Locations for Turbine Building Basement Structures Measurement ID Coordinates X-Axis (meters)

Y-Axis (meters)

B3-06100A-FRWC-001-GD 295.63 252.07 B3-06100A-FRWC-002-GD 449.65

-135.25 B3-06100A-FRFC-003-GD 141.60 37.94 B3-06100A-FRWC-004-GD 757.71 213.14 B3-06100A-FRWC-005-GD 64.59 271.54 B3-06100A-FRWC-006-GD 584.43 216.02 B3-06100A-FRWC-007-GD 45.33

-114.9 B3-06100A-FRFC-008-GD 314.88 21.36 B3-06100A-FQWC-009-GD 468.91 254.96 B3-06100A-FRWC-009-GD 468.91 254.96 B3-06100A-FRWC-010-GD 160.85

-244.68 B3-06100A-FRFC-011-GD 545.92 47.31 B3-06100A-FRFC-012-GD 112.72 66.78 B3-06100A-FRFC-013-GD 343.76

-30.55 B3-06100A-FRWC-014-GD 305.25

-238.19 In addition to the random measurements, an additional 16 ISOCS measurements were taken at judgmental locations. The selection of these locations was based upon the results of past operational and characterization surveys, which provided indication that these areas had a higher probability for the presence of residual radioactivity. Measurement locations for the ISOCS measurements taken at judgmental locations are listed in Table 10. A map of the judgmental ISOCS measurement locations taken in the Turbine Building basement is provided in Figure 6 in Attachment 1.

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Table 10 - Judgmental ISOCS Measurement Locations for Turbine Building Basement Structures Measurement ID Location B3-06100A-FJWC-015-GD C/D Oil Room East Wall B3-06100A-FJWC-016-GD C/D Oil Room North Wall B3-06100A-FJWC-017-GD Unit 1 510 foot Valve Pit B3-06100A-FJWC-018-GD Unit 2 510 foot Valve Pit B3-06100A-FJFC-019-GD Elevator Sump Floor B3-06100A-FJFC-020-GD Unit 1 Eq. Drain Sump B3-06100A-FJWC-021-GD Unit 2 Eq. Drain Sump B3-06100A-FJFC-022-GD Unit 2 CW Surge Line B3-06100A-FJFC-023-GD Unit 1 Col. G-27 B3-06100A-FJFC-024-GD Unit 1 Col. G-25 B3-06100A-FJFC-025-GD Central Floor Drain Sump B3-06100A-FJFC-026-GD Central Fire Sump B3-06100A-FJWC-027-GD Central Fire Sump B3-06100A-FJWC-028-GD EVS 1 B3-06100A-FJWC-030-GD EVS 2 B3-06100A-FJWC-031-GD EVS 1 The area of the floors and walls of the Unit 1 and Unit 2 Steam Tunnels are also part of survey unit 06100. Fourteen (14) additional ISOCS measurement locations were selected at random on the walls and floors of the Steam Tunnels. The random locations of the ISOCS measurements were selected using VSP, in accordance with ZS-LT-300-001-001. Input parameters included use of a grid layout and the random sampling tool set with a predetermined number (14) of measurement points. These fourteen (14) measurements were added to the fourteen (14) measurements taken on the 560 foot elevation of the Turbine Building basement resulting in a population of 28 measurements. Measurement locations for the ISOCS measurements taken for survey design in Unit 1 and Unit 2 Steam Tunnels are listed in Table

11. A map of the random ISOCS measurement locations for the Unit 1 and Unit 2 Steam Tunnels is provided in Figure 7 in Attachment 1.

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Table 11 - Random ISOCS Measurement Locations for Unit 1 and Unit 2 Steam Tunnels Measurement ID Location B3-06100B-FRFC-007-GD Floor B3-06100B-FRFC-008-GD Floor B3-06100B-FRWC-009-GD North Wall B3-06100B-FRWC-010-GD North Wall B3-06100B-FRWC-011-GD South Wall B3-06100B-FQWC-011-GD South Wall B3-06100B-FRWC-012-GD South Wall B3-06100B-FRWC-013-GD South Wall B3-06100B-FRWC-014-GD South Wall B3-06100B-FRWC-015-GD South Wall B3-06100B-FRWC-016-GD North Wall B3-06100B-FRWC-017-GD North Wall B3-06100B-FRWC-018-GD North Wall B3-06100B-FRWC-019-GD North Wall B3-06100B-FRFC-020-GD Floor In addition to the random measurements, an additiona) ISOCS measurements were taken at judgmental locations in the Steam Tunnels. The selection of these locations was based upon the results of past operational and characterization surveys which provided indication that these areas had a higher probability for the presence of residual radioactivity. Measurement locations for the ISOCS measurements taken at judgmental locations in the Steam Tunnels are listed in Table 12. A map of the judgmental ISOCS measurement locations taken in the Steam Tunnels is provided in Figure 7 in Attachment 1.

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Table 12 - Judgmental ISOCS Measurement Locations for Unit 1 and Unit 2 Steam Tunnels Measurement ID Location B3-06100B-FJWC-001-GD Unit 1 North east wall B3-06100B-FJWC-002-GD Unit 1 South east wall B3-06100B-FJFC-003-GD Unit 1 Floor B3-06100B-FJWC-004-GD Unit 2 North east wall B3-06100B-FJWC-005-GD Unit 2 South east wall B3-06100B-FJFC-006-GD Unit 2 Floor B3-06100B-FJWC-021-GD Unit 2 West Wall B3-06100B-FJWC-022-GD Unit 1 North Wall Revision 2 of ZSRP LTP Chapter 5, section 5.1 states that concrete core samples will be collected during FSS to confirm the HTD to surrogate radionuclide ratios. The FSS of the Turbine Building basement walls and floors was completed prior to issuance of Revision 2 of the LTP, when this commitment was made. The basement below the 588 foot elevation has been backfilled and is no longer accessible. Therefore, no concrete core samples were acquired during FSS. However, as previously stated, ZionSolutions acquired and analyzed 10 concrete core samples during site characterization. Only Cs-137 was positively identified at detectable concentrations in these samples and at very low concentrations. In addition, 4 concrete core samples were acquired during the FSS of the Unit 1 and Unit 2 Diesel Fuel Oil Storage Tank Rooms on the Turbine Building 570 foot elevation. Those samples were analyzed for the HTD ROC. The results of those samples are addressed in the Release Records for Unit 1 and Unit 2 Diesel Fuel Oil Storage Tank Rooms which are attached as Appendixes to this Release Record.

Fourteen (14) ISOCS measurements were required for the survey of the Unit 1 and Unit 2 Circulating Water Discharge Tunnels. Access to the Circulating Water Discharge Tunnels is very limited and therefore, these areas were surveyed as biased areas using judgmental measurements. Sample plan B3-09200B was generated for the acquisition of the judgmental ISOCS measurements in these Tunnels.

In March of 2016, the Circulating Water Discharge Tunnels were drained and surveyed.

Continuing characterization was combined with FSS due to the low levels of residual radioactivity that was expected to remain. Judgmental FSS measurements using the ISOCS were located on surfaces within the Tunnels that could be accessed safely. Measurement locations for the judgmental ISOCS measurements are listed with the grid coordinates, based on a local origin selected by the survey designer, in Table 13. A map of the judgmental ISOCS

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measurement locations for the Circulating Water Discharge Tunnels is provided in Figure 8 in.

Table 13 - Judgmental ISOCS Measurement Locations for Circulating Water Discharge Tunnels Measurement ID Coordinates X-Axis (meters)

Y-Axis (meters)

B3-09200B-FJCC-001-GD 7.3 0.64 B3-09200B-FJWC-002-GD 153.1 11.6 B3-09200B-FJFC-003-GD 9.1 331.1 B3-09200B-FJWC-004-GD 16.57

-61.20 B3-09200B-FJFC-005-GD 9.0 327.0 B3-09200B-FJWC-006-GD 58.48

-110.95 B3-09200B-FJWC-007-GD

-147.8 10.8 B3-09200B-FJCC-008-GD 9.0 327.0 B3-09200B-FJCC-009-GD 23.1 252.5 B3-09200B-FJFC-010-GD 9.2 66.7 B3-09200B-FJWC-011-GD

-31.3 4.4 B3-09200B-FJWC-012-GD

-142.8 10.8 B3-09200B-FJFC-013-GD 16.7 4.5 B3-09200B-FJFC-014-GD 8.9 327.2 The survey unit for the Circulating Water Discharge Pipes consisted of the 48-inch internal diameter (ID) crossover sections of both Unit 1 and Unit 2. On the 560 foot elevation of the Turbine Building, there were two 510 foot Valve Pits that housed the 48-inch diameter Circulating Water Discharge Pipes. The 510 foot valve was removed from the Unit 1 and Unit 2 pits, leaving the 48-inch Circulating Water Discharge Pipes exposed. The 48-inch pipe was cut, leaving the north and south section of the pipe open for survey as shown in Figure 5.

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Figure 5 - 510 Valve Pit Circulating Water Discharge Pipe The FSS consisted of two (2) judgmental ISOCS measurements in each pipe opening, one to the north and one to the south. The interior of both pipes had a surface area of 760 m2, but the only accessible portions of the pipe were the sections open to the Valve Houses. Judgmental ISOCS measurement locations are listed in Table 14.

Table 14 - Judgmental ISOCS Measurement Locations for Circulating Water Discharge Pipe Measurement ID Location S3-06105A-FJSM-001-GD Unit 1 North Section S3-06105A-FJSM-002-GD Unit 1 South Section S3-06105A-FJSM-003-GD Unit 2 North Section S3-06105A-FJSM-004-GD Unit 2 South Section A map of the judgmental ISOCS measurement locations for the Circulating Water Discharge Pipes is provided in Figure 9 in Attachment 1.

The implementation of quality control measures as referenced by LTP Chapter 5, section 5.9 and ZionSolutions ZS-LT-01, Quality Assurance Project Plan (for Characterization and FSS) (QAPP) (Reference 12) includes the collection of a replicate measurement at 5% of the locations selected at random. One (1) ISOCS measurement, B3-06100A-FQWC-09-GD, was selected randomly for the replicate measurement for the Turbine Building basement. One (1)

ISOCS measurement, B3-06100B-FQWC-011-GD, was selected randomly for the replicate

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measurement for the Unit 1 and Unit 2 Steam Tunnels. An additional replicate ISOCS measurement, B3-09200B-FQCC-009-GD, was selected for the judgmental measurements taken in the Circulating Water Discharge Tunnel.

The areal scan coverage requirements for FSS of structures as specified in the LTP is commensurate with the probability that a small area of elevated activity could exist within a FSS unit at a concentration exceeding the BcDCGL and the likelihood that such an area would not be detected by the FSS ISOCS measurements. It is highly unlikely that the ISOCS, with a nominal Field of View (FOV) of approximately 28 m2 would not detect and account for elevated areas. The primary basis used to determine reasonable areal coverage for the ISOCS measurements is the potential for the OpDCGL to be exceeded. The criteria for selecting reasonable and risk-informed areal coverage is based on a graded approach similar to the guidance for scan surveys during FSS provided in MARSSIM, where the coverage is based on the expected fraction of the DCGL (in this case, OpDCGL).

As a Class 3 survey unit, LTP Chapter 5, Table 5-19, reproduced as Table 8, specifies that a minimum of 392 m2 or 3% of the accessible surface area in the Turbine Building structural basement survey unit will be subjected to scan coverage. The surface area covered by a single ISOCS measurement is large (a nominal range of 10-30 m2), and the FOV of the measurement becomes a substitute for scanning that is typically performed by moving a hand-held detector over the surface in question. Twenty-eight (28) ISOCS measurements were taken of the Turbine Building and Steam Tunnel basement surfaces, representing an areal coverage of 792 m2. In addition, twenty-four (24) judgmental ISOCS measurements were taken in the Turbine Building basement and Steam Tunnels, providing for another 799 m2 of areal coverage. Four (4) judgmental measurements were also taken in the Circulating Water Discharge Pipe, which is included with the surface area of the Turbine Building. Those measurements add an additional 113 m2 to the areal coverage. The total areal coverage of the FSS performed of the Turbine Building basement and Steam Tunnels, including the Circulating Water Discharge Pipe, was 1,704 m2 or 6.3%, which is far in excess of the areal coverage requirements stated in LTP Chapter 5, Table 5-19. Table 8 also specifies that a minimum of 392 m2 or 8% of the accessible surface area in the Circulating Water Discharge Tunnel survey unit will be subjected to scan coverage. The fourteen (14) judgmental measurements provided 396 m2 of areal coverage, again in excess of the areal coverage requirements stated in LTP Chapter 5, Table 5-

19. For these basement survey units, the Investigation Levels are those levels specified in LTP Chapter 5, Table 5-25 and are reproduced below in Table 15.

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Table 15 - Investigation Levels Classification Direct Measurement Class 1

> OpDCGL Class 2

> OpDCGL Class 3

> 0.5 OpDCGL Table 16 provides a synopsis of the survey design for survey units 06100, 09200B and 06105A.

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Table 16 - Synopsis of Survey Design Feature Survey Unit Basis Survey Unit 06100 Survey Unit 09200 Survey Unit 06105A Survey Unit Area 27,135 m2 (total area incl. all areas) 4,868 1,075 (LTP Chapter 6, Tables 6-22 and 6-23)

Number of Measurements 28 Random, 24 Judgmental 14 Judgmental 4 Judgmental (LTP Chapter 5, Table 5-19)

Measurement Spacing Random Biased Biased (LTP Chapter 5, Section 5.6.4)

DCGLs (pCi/m2)

  • Cs-134 1.35E+06
  • Cs-134 6.65E+06
  • Cs-134 1.35E+06
  • Cs-137 1.79E+06 Operational DCGLs, (LTP Chapter 5, Table 5-4)

Measurement Investigation Level

>0.5 OpDCGL

>0.5 OpDCGL

>0.5 OpDCGL (LTP Chapter 5, Table 5-25)

Scan Survey Area Coverage 392 m2 or 3%

392 m2 or 8%

(incl. with Turbine Building Area)

(LTP Chapter 5, Table 5-19)

QC 5% of measurement 5% of measurement N/A (LTP Chapter 5, section 5.9.3.1)

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6.

SURVEY IMPLEMENTATION Survey instructions for this FSS were incorporated into and performed in accordance with FSS Sample Plans B3-06100 Turbine Building, B3-09200B Circulating Water Discharge Tunnels and S3-06105A Unit 1 and Unit 2 Circulating Water Discharge Pipe, which were developed in accordance with ZionSolutions procedure ZS-LT-300-001-001. All FSS units were inspected and controlled in accordance with ZionSolutions procedure ZS-LT-300-001-003, Isolation and Control for Final Status Survey (Reference 13). Compliance with the unrestricted release criteria was demonstrated through direct measurements using the ISOCS.

FSS field activities commenced in the Turbine Building basement in March of 2016. A Field Log (ZS-LT-300-001-001 Attachment 14) was used to document field activities and other information pertaining to the performance of the FSS.

FSS field activities were projected to take 12 working days to complete FSS in all three areas.

Daily briefings were conducted to discuss the expectations for job performance and to review safety aspects of the job.

ZionSolutions TSD 14-022, Use of In-Situ Gamma Spectroscopy for Final Status Survey of End State Structures (Reference 14) provides the initial justification for the selection of reasonably conservative geometries for efficiency calibrations for the ISOCS based on the physical conditions of the remediated surface and the anticipated depth and distribution of activity. Prior to implementing the sample plan for the FSS of the Turbine Building basement structure and the Circulating Water Discharge Tunnel, the physical condition of the surfaces to be surveyed were assessed to ensure that the geometry was not significantly changed from that assumed in TSD 14-022. Most ISOCS measurements were acquired using the geometry labeled as TBFLOOR, which assumed a circular plane source with a contaminant depth of 1 half-inch. With the 90-degree collimation shield installed and a stand-off distance of 3 meters, this orientation corresponded to a nominal FOV of 28 m2. Other geometries were used where the physical configuration of the measurement was different than a circular plane. For example, unique geometries were used for measurements taken in valve boxes and sumps.

Unique ISOCS geometries were also employed for the measurements taken in the Circulating Water Discharge Tunnels and Circulating Water Discharge Pipe. A stand-off guide attached to the detector was used to establish a consistent source to detector distance and center the detector over the selected measurement location. The details pertaining to ISOCS geometries are provided in Attachment 2.

The 28 random ISOCS measurement locations were marked based on grid coordinates provided by VSP. Replicate measurements were also acquired in the Turbine Building basement at locations B3-06100A-FQWC-09-GD, B3-6100B-FQWC-011-GD and in the Circulating Water Discharge Tunnels at location B3-09200B-FQCC-009-GD.

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7.

SURVEY RESULTS Direct measurements were acquired at each random location in the Turbine Building basement and Steam Tunnels and at the selected judgmental locations in the Turbine Building basement, the Circulating Water Discharge Pipe and the Circulating Water Discharge Tunnels using the ISOCS. A summary of the results of the 28 ISOCS measurements taken for non-parametric statistical testing are provided in Table 17. The concentrations for Ni-63 and Sr-90 were inferred based on the maximum ratios as specified in Table 5. The complete ISOCS gamma spectroscopy reports are presented in Attachment 6.

The SOF or unity rule is the mathematical test used to evaluate compliance with radiological criteria for license termination when more than one radionuclide has been determined to be potentially present. The equation for the unity rule is:

Equation 4 Where:

Cn

= concentration of radionuclide n DCGLn

= DCGL of radionuclide n.

The basic statistics for the random measurements are summarized in Table 18.

Table 17 - Summary of ISOCS Results for Random Measurements Measurement ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-06100A-FRWC-001-GD 1.30E+04 1.60E+04 1.59E+04 2.35E+06 3.18E+01 0.036 B3-06100A-FRWC-002-GD 1.34E+04 1.97E+04 1.80E+04 2.42E+06 3.60E+01 0.041 B3-06100A-FRFC-003-GD 4.49E+03 6.34E+03 4.91E+03 8.10E+05 9.82E+00 0.013 B3-06100A-FRWC-004-GD 1.43E+04 1.66E+04 1.89E+04 2.58E+06 3.78E+01 0.040 B3-06100A-FRWC-005-GD 1.43E+04 1.80E+04 1.89E+04 2.58E+06 3.78E+01 0.041 B3-06100A-FRWC-006-GD 1.15E+04 1.57E+04 2.07E+04 2.08E+06 4.14E+01 0.037 B3-06100A-FRWC-007-GD 1.15E+04 1.93E+04 1.33E+04 2.08E+06 2.66E+01 0.035 B3-06100A-FRFC-008-GD 6.68E+03 8.20E+03 9.02E+03 1.21E+06 1.80E+01 0.019 B3-06100A-FRWC-009-GD 1.20E+04 1.66E+04 1.82E+04 2.17E+06 3.64E+01 0.037 B3-06100A-FRWC-010-GD 1.47E+04 1.57E+04 1.75E+04 2.65E+06 3.50E+01 0.039 B3-06100A-FRFC-011-GD 1.43E+04 1.75E+04 1.93E+04 2.58E+06 3.86E+01 0.041 1

2 2

1 1

+

+

DCGL C

DCGL C

DCGL C

n n

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Table 17 (continued) - Summary of ISOCS Results for Random Measurements Measurement ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-06100A-FRFC-012-GD 1.39E+04 1.97E+04 1.95E+04 2.51E+06 3.90E+01 0.042 B3-06100A-FRFC-013-GD 1.20E+04 1.97E+04 2.28E+04 2.17E+06 4.56E+01 0.042 B3-06100A-FRFC-014-GD 1.13E+04 1.69E+04 1.73E+04 2.04E+06 3.46E+01 0.036 B3-06100B-FRFC-007-GD 1.53E+05 2.05E+05 2.00E+05 2.76E+07 4.00E+02 0.444 B3-06100B-FRFC-008-GD 1.68E+05 2.14E+05 1.69E+06 3.03E+07 3.38E+03 1.346 B3-06100B-FRWC-009-GD 1.47E+05 1.98E+05 1.95E+05 2.65E+07 3.90E+02 0.429 B3-06100B-FRWC-010-GD 1.44E+05 1.97E+05 2.80E+05 2.60E+07 5.60E+02 0.475 B3-06100B-FRWC-011-GD 1.58E+05 1.85E+05 1.97E+05 2.85E+07 3.94E+02 0.434 B3-06100B-FRWC-012-GD 1.37E+05 7.71E+03 1.82E+05 2.47E+07 3.64E+02 0.269 B3-06100B-FRWC-013-GD 1.49E+05 1.94E+05 2.33E+05 2.69E+07 4.66E+02 0.451 B3-06100B-FRWC-014-GD 1.32E+05 1.64E+05 1.80E+05 2.38E+07 3.60E+02 0.378 B3-06100B-FRWC-015-GD 1.32E+05 1.89E+05 1.85E+05 2.38E+07 3.70E+02 0.400 B3-06100B-FRWC-016-GD 1.32E+05 1.85E+05 1.84E+05 2.38E+07 3.68E+02 0.396 B3-06100B-FRWC-017-GD 1.73E+05 2.14E+05 1.95E+05 3.12E+07 3.90E+02 0.471 B3-06100B-FRWC-018-GD 1.47E+05 1.76E+05 2.03E+05 2.65E+07 4.06E+02 0.418 B3-06100B-FRWC-019-GD 1.32E+05 2.06E+05 1.98E+05 2.38E+07 3.96E+02 0.420 B3-06100B-FRFC-020-GD 1.43E+04 1.95E+04 2.10E+04 2.58E+06 4.20E+01 0.043 (1) Concentrations are inferred One measurement, B3-06100B-FRFC-008-GD, exceeded an OpSOF of 1 when compared against the OpDCGLs for the Turbine Building basement. This measurement was taken on the floor in the Unit 1 Steam Tunnel at the entrance to the East Valve House. However, when compared against the BILs, the measurement presented a SOF of 0.117. Consequently, no action or investigation was taken at the time the survey was performed in 2016. The BcSOF, when compared against the BcDCGLs for this individual measurement is 0.114. The adjustment to the mean BcSOF from elevated measurement B3-06100B-FRFC-008-GD is 0.000 (see Attachment 3).

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Table 18 - Basic Statistical Properties of Random ISOCS Measurements Individual Measurement Metrics Total Number of Systematic Measurements =

20 Number of Quality Control Measurements =

2 Number of Judgmental/Investigational Measurements =

0 Total Number of Measurements =

22 Mean Systematic Measurement OpSOF

=

0.245 Max Individual Systematic Measurement OpSOF

=

1.346 Number of Systematic Measurements with OpSOF >1

=

1 Statistical Quantities - Systematic Measurement Population ROC Mean Median Max Min Std. Dev.

BcDCGL Avg. SOF Avg. Dose (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2) per ROC Per ROC Co-60 7.45E+04 1.45E.04 1.73E+05 4.49E+03 6.89E+04 7.03E+07 0.001 0.026 Cs-134 9.21E+04 1.97E+04 2.14E+05 6.34E+03 9.03E+04 1.59E+07 0.006 0.145 Cs-137 1.56E+05 2.19E+04 1.69E+06 4.91E+03 3.15E+05 2.11E+07 0.007 0.185 Ni-63 1.34E+07 2.62E+06 3.12E+07 8.10E+05 1.24E+07 2.18E+09 0.006 0.154 Sr-90 3.13E+02 4.38E+01 3.38E+03 9.82E+00 6.30+02 7.74E+05 0.000 0.010 The mean BcSOF from random measurements taken on basement structural surfaces in survey unit 06100 is 0.021. This is derived by summing the average BcSOF per ROC resulting from the average concentration in Table 18. The adjustment to the mean BcSOF from elevated measurement B3-06100B-FRFC-008-GD is 0.000. The adjusted mean BcSOF for survey unit 06100 is 0.021, which equates to a dose of 0.523 mrem/yr.

The implementation of required QC measurements included the collection of 2 additional ISOCS measurement at locations 9 (B3-06100A-FQWC-09-GD) and 11 (B3-06100B-FQWC-011-GD) for replicate measurements analysis. The replicate ISOCS measurement results are provided in Table 19. The concentration for Ni-63 and Sr-90 are inferred based on the maximum ratios as specified in Table 5.

Table 19 - Summary of ISOCS Replicate Measurements for QC Measurement ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-06100A-FQWC-009-GD 1.53E+04 1.80E+04 1.59E+04 2.76E+06 3.18E+01 0.003 B3-06100B-FQWC-011-GD 1.51E+05 1.75E+05 1.71E+05 2.72E+07 3.42E+02 0.002 (1) Concentrations are inferred

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Twenty-four (24) judgmental measurements were acquired in the Turbine Building and in the Steam Tunnels. A summary of the results are provided in Table 20. The concentration for Ni-63 and Sr-90 were inferred based on the maximum ratios as specified in Table 5. The complete ISOCS gamma spectroscopy reports are presented in Attachment 6.

Table 20 - Summary of ISOCS Results for Judgmental Measurements Taken in the Turbine Building Basement and Steam Tunnels Measurement ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-06100B-FJWC-015-GD 7.13E+03 9.62E+03 1.13E+04 1.29E+06 2.26E+01 0.022 B3-06100B-FJWC-016-GD 4.44E+03 2.60E+04 4.67E+03 8.02E+05 9.34E+00 0.027 B3-06100A-FJW-017-GD 0.00E+00 4.92E+04 8.06E+04 0.00E+00 1.61E+02 0.084 B3-06100A-FJWC-018-GD 1.16E+05 0.00E+00 1.37E+06 2.08E+07 2.75E+03 0.941 B3-06100A-FJFC-019-GD 0.00E+00 3.50E+04 0.00E+00 0.00E+00 0.00E+00 0.026 B3-06100A-FJFC-020-GD 5.81E+04 2.07E+05 4.21E+05 1.05E+07 8.41E+02 0.467 B3-06100A-FJWC-021-GD 2.22E+04 9.19E+04 3.23E+05 4.00E+06 6.46E+02 0.284 B3-06100A-FJFC-022-GD 1.68E+04 1.69E+04 5.52E+04 3.03E+06 1.10E+02 0.064 B3-06100A-FJFC-023-GD 1.28E+04 1.80E+04 3.27E+03 2.31E+06 6.53E+00 0.030 B3-06100A-FJFC-024-GD 0.00E+00 1.57E+04 0.00E+00 0.00E+00 0.00E+00 0.012 B3-06100A-FJFC-025-GD 1.31E+05 2.58E+05 9.34E+05 2.37E+07 1.87E+03 0.891 B3-06100A-FJFC-026-GD 1.74E+04 1.75E+04 7.42E+04 3.14E+06 1.48E+02 0.077 B3-06100A-FJWC-027-GD 2.85E+04 3.22E+04 2.56E+05 5.14E+06 5.11E+02 0.207 B3-06100A-FJWC-028-GD 7.00E+02 1.36E+03 1.42E+05 1.26E+05 2.84E+02 0.086 B3-06100A-FJWC-030-GD 1.37E+04 1.89E+04 1.89E+04 2.47E+06 3.78E+01 0.041 B3-06100A-FJWC-031-GD 1.50E+04 1.74E+04 1.70E+05 2.71E+06 3.40E+02 0.130 B3-06100B-FJWC-001-GD 1.62E+04 1.80E+04 5.65E+04 2.92E+06 1.13E+02 0.006 B3-06100B-FJWC-002-GD 1.34E+04 2.18E+04 1.80E+04 2.42E+06 3.60E+01 0.004 B3-06100B-FJFC-003-GD 4.67E+03 6.69E+03 7.24E+03 8.43E+05 1.45E+01 0.001 B3-06100B-FJWC-004-GD 1.34E+04 2.09E+04 2.08E+04 2.42E+06 4.16E+01 0.004 B3-06100B-FJWC-005-GD 1.43E+04 1.80E+04 1.84E+04 2.58E+06 3.68E+01 0.003 B3-06100B-FJFC-006-GD 4.58E+03 6.02E+03 7.91E+03 8.26E+05 1.58E+01 0.001 B3-06100B-FJWC-021-GD 1.49E+05 1.92E+05 1.87E+05 2.69E+07 3.74E+02 0.268 B3-06100B-FJWC-022-GD 1.49E+05 1.85E+05 2.04E+05 2.69E+07 4.08E+02 0.271 (1) Concentrations are inferred

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Of the twenty-four (24) judgmental samples taken, two (2) measurements exceeded an OpSOF of 0.5. Measurement B3-06100A-FJWC-018-GD, which was taken in the 510 foot Valve Pit has an OpSOF of 0.941 and B3-06100A-FJFC-025-GD, which was taken in the Floor Drain Sump, had an OpSOF of 0.891. When compared against the BILs, the SOF for measurement B3-06100A-FJWC-018-GD was 0.081 and the SOF for B3-06100A-FJFC-025-GD was 0.077.

Consequently, no action or investigation was taken at the time the survey was performed.

When compared against the BcDCGLs, the BcSOF for measurement B3-06100A-FJWC-018-GD is 0.080 and the BcSOF for measurement B3-06100A-FJFC-025-GD was 0.076.

Four (4) judgmental ISOCS measurements were taken within the Unit 1 and Unit 2 Circulating Water Discharge Pipe. A summary of the results of the four (4) judgmental ISOCS measurements taken within the Circulating Water Discharge Pipe are provided in Table 21.

The concentration for Ni-63 and Sr-90 were inferred based on the maximum ratios as specified in Table 5. The complete ISOCS gamma spectroscopy reports are presented in Attachment 6.

Table 21 - Summary of Gamma Spectroscopy Results for Judgmental ISOCS Measurements Taken in Circulating Water Discharge Pipes Measurement ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-06105A-FJSM-001-GD 1.60E+04 1.15E+04 1.28E+04 2.89E+06 2.56E+01 0.034 B3-06105A-FJSM-002-GD 9.20E+03 1.07E+04 1.25E+04 1.66E+06 2.50E+01 0.026 B3-06105A-FJSM-003-GD 2.64E+05 5.49E+04 1.26E+05 4.76E+07 2.52E+02 0.417 B3-06105A-FJSM-004-GD 2.63E+04 2.05E+04 1.05E+05 4.75E+06 2.10E+02 0.107 (1) Concentrations are inferred In order to assess the dose contribution from the Circulating Water Discharge Pipe, the concentration of each ROC in each judgmental measurement was also compared against the respective BcDCGLs. The calculation of the mean BcSOF for the Circulating Water Discharge Pipe and the resultant dose is presented in Table 22.

Table 22 - Basic Statistical Properties of Judgmental ISOCS Measurements in Circulating Water Discharge Pipe Individual Measurement Metrics Total Number of Systematic Measurements =

4 Number of Quality Control Measurements =

0 Number of Judgmental/Investigational Measurements =

0 Total Number of Measurements =

4

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Table 22 (continued) - Basic Statistical Properties of Judgmental ISOCS Measurements in Circulating Water Discharge Pipe Mean Systematic Measurement OpSOF

=

0.146 Max Individual Systematic Measurement OpSOF

=

0.417 Number of Systematic Measurements with OpSOF >1

=

0 Statistical Quantities - Systematic Measurement Population ROC Mean Median Max Min Std. Dev.

BcDCGL Avg. SOF Avg. Dose (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2) per ROC Per ROC Co-60 7.89E+04 2.12E+04 2.64E+05 9.20E+03 1.24E+05 7.03E+07 0.001 0.028 Cs-134 2.44E+04 1.60E+04 5.49E+04 1.07E+04 2.08E+04 1.59E+07 0.002 0.038 Cs-137 6.41E+04 5.89E+04 1.26E+05 1.25E+04 6.00E+04 2.11E+07 0.003 0.076 Ni-63 1.42E+07 3.82E+06 4.76E+07 1.66E+06 2.23E+07 2.18E+09 0.007 0.163 Sr-90 1.28E+02 1.18E+02 2.52E+02 2.50E+01 1.20E+02 7.74E+05 0.000 0.004 The mean BcSOF from the judgmental measurements taken on the Circulating Water Discharge Pipe in survey unit 06105A is 0.012. This equates to a dose of 0.310 mrem/yr. This is derived by summing the average BcSOF per ROC resulting from the average concentration in Table 22. There were no identified elevated areas.

Fourteen (14) judgmental ISOCS measurements were taken within the Unit 1 and Unit 2 Circulating Water Discharge Tunnels. A summary of the results of the 14 judgmental measurements are provided in Table 23. The concentration for Ni-63 and Sr-90 were inferred based on the maximum ratios as specified in Table 5. The complete ISOCS gamma spectroscopy reports are presented in Attachment 6.

Table 23 - Summary of Results for Judgmental Measurements Taken in the Circulating Water Discharge Tunnels Measurement ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-09200B-FRCC-001-GD 1.66E+04 1.63E+04 1.99E+04 3.00E+06 3.98E+01 0.009 B3-09200B-FRWC-002-GD 1.51E+04 1.69E+04 1.84E+04 2.72E+06 3.68E+01 0.008 B3-09200B-FRFC-003-GD 1.08E+04 1.79E+04 1.42E+04 1.95E+06 2.84E+01 0.007 B3-09200B-FRWC-004-GD 1.43E+04 1.77E+04 1.93E+04 2.58E+06 3.86E+01 0.008 B3-09200B-FRFC-005-GD 9.51E+06 8.85E+04 2.66E+05 1.72E+09 5.32E+02 2.252 B3-09200B-FRWC-006-GD 1.15E+04 1.83E+04 1.89E+04 2.08E+06 3.78E+01 0.008

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Table 23 (continued) - Summary of Results for Judgmental Measurements Taken in the Circulating Water Discharge Tunnels Measurement ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-09200B-FRWC-007-GD 2.59E+04 2.18E+04 2.10E+04 4.67E+06 4.20E+01 0.012 B3-09200B-FRCC-008-GD 6.89E+06 7.40E+04 2.69E+05 1.24E+09 5.38E+02 1.641 B3-09200B-FRCC-009-GD 1.43E+04 1.88E+04 1.82E+04 2.58E+06 3.64E+01 0.008 B3-09200B-FRFC-010-GD 1.43E+04 1.88E+04 1.84E+04 2.58E+06 3.68E+01 0.008 B3-09200B-FRWC-011-GD 1.22E+04 1.30E+04 1.96E+04 2.20E+06 3.92E+01 0.007 B3-09200B-FRWC-012-GD 2.51E+04 2.11E+04 1.99E+04 4.53E+06 3.98E+01 0.011 B3-09200B-FRFC-013-GD 1.34E+04 1.88E+04 1.68E+04 2.42E+06 3.36E+01 0.008 B3-09200B-FRFC-014-GD 8.73E+03 1.08E+04 1.65E+04 1.58E+06 3.30E+01 0.006 (1) Concentrations are inferred The Circulating Water Discharge Tunnels were the main authorized effluent release pathway for the discharge of treated and filtered radioactive liquid effluent to Lake Michigan. During plant operations and during decommissioning until the pathway was secured in October of 2015, the liquid effluent release pathway was monitored and the results presented in the annual REMP report in accordance with the ODCM. The release of effluent during decommissioning was made at the west end of the Discharge Tunnel in the steel lined area under the 12-foot diameter Down-comer pipes. Judgmental measurements B3-09200B-FRFC-005-GD and B3-09200B-FRCC-008-GD were taken on the floor under the Unit 2 Down-comer pipe where the effluent was released during decommissioning.

All FSS ISOCS measurements results in both Unit 1 and Unit 2 Circulating Water Discharge Tunnels were less than an OpSOF of 0.5 with the exception of the area under the Unit 2 Down-comer pipe. When compared against the OpDCGLs, judgmental measurements B3-09200B-FRFC-005-GD and B3-09200B-FRCC-008-GD resulted in OpSOF of 2.252 and 1.641 respectively. Co-60 and Cs-137 were positively identified in both measurements. When compared against the BILs, both measurements presented a SOF of 0.162 and 0.118 respectively. Consequently, no action or investigation was taken at the time the survey was performed. The BcSOF for both measurements were 0.941 and 0.686 respectively. The adjustment to the mean BcSOF from elevated measurements B3-09200B-FRFC-005-GD and B3-09200B-FRCC-008-GD is 0.008 (see Attachment 3).

In order to assess the dose contribution from the Circulating Water Discharge Tunnels, the concentration of each ROC in each judgmental measurement was also compared against the respective BcDCGLs. The calculation of the mean BcSOF for the Circulating Water Discharge Tunnels and the resultant dose is presented in Table 24.

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Table 24 - Basic Statistical Properties of Judgmental ISOCS Measurements in Circulating Water Discharge Tunnel Individual Measurement Metrics Total Number of Systematic Measurements =

14 Number of Quality Control Measurements =

1 Number of Judgmental/Investigational Measurements =

0 Total Number of Measurements =

15 Mean Systematic Measurement OpSOF

=

0.285 Max Individual Systematic Measurement OpSOF

=

2.252 Number of Systematic Measurements with OpSOF >1

=

2 Statistical Quantities - Systematic Measurement Population ROC Mean Median Max Min Std. Dev.

BcDCGL Avg. SOF Avg. Dose (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2) per ROC Per ROC Co-60 1.18E+06 1.43E+04 9.51E+06 8.73E+03 3.02E+06 7.03E+07 0.017 0.421 Cs-134 2.66E+04 1.86E+04 8.85E+04 1.08E+04 2.35E+04 1.59E+07 0.002 0.042 Cs-137 5.40E+04 1.91E+04 2.69E+05 1.42E+04 9.05E+04 2.11E+07 0.003 0.064 Ni-63 2.14E+08 2.58E+06 1.72E+09 1.58E+06 5.44E+08 2.18E+09 0.098 2.450 Sr-90 1.08E+02 3.82E+01 5.38E+02 2.84E+01 1.81E+02 7.74E+05 0.000 0.003 The mean BcSOF from random measurements taken on basement structural surfaces in survey unit 09200 is 0.119. This is derived by summing the average BcSOF per ROC resulting from the average concentration in Table 24. The adjustment to the mean BcSOF from elevated measurements B3-09200B-FRFC-005-GD and B3-09200B-FRCC-008-GD is 0.008. The adjusted mean BcSOF for survey unit 09200 is 0.127, which equates to a dose of 3.180 mrem/yr.

A replicate measurement was acquired in the Circulating Water Discharge Tunnels at location B3-09200B-FQCC-009-GD. A summary of the result for the QC replicate measurement is provided in Table 25.

Table 25 - Summary of Replicate Measurement Taken in Circulating Water Discharge Tunnel for QC MEASUREMENT ID Co-60 Cs-134 Cs-137 Ni-63(1)

Sr-90(1)

OpSOF (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

B3-09200B-FQCC-009-GD 1.04E+04 2.00E+04 1.95E+04 1.88E+06 3.90E+01 0.008 (1) Concentrations are inferred

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Appendixes 1 through 13 present Release Records of FSS performed on ancillary areas and embedded pipe associated with the Turbine Building basement following the initial FSS performed in March of 2016. These areas were either not accessible or deferred at the time the Turbine Building basement was subjected to FSS. For example, the Unit 1 and Unit 2 Diesel Generator rooms on the 570 foot elevation are part of the surface area of the Turbine Building as specified in LTP Chapter 6, section 6.6.8.1. During decommissioning, both areas were used as the transit path for radioactive materials removed from the Auxiliary Building. This activity was active after the FSS performed in 2016 and was completed in 2018. Consequently, both Diesel Generator rooms were resurveyed for compliance as Class 1 areas. These Release Records are as follows;

  • Appendix 10a - 06105B - Turbine Building 560 foot Embedded Floor Drain Pipe
  • Appendix 10b - 06107 - Unit 1 Tendon Buttress Pits
  • Appendix 10c - 06108 - Unit 2 Tendon Buttress Pits
  • Appendix 10d - 06201 - Unit 1 Diesel Fuel Oil Storage Tank Room
  • Appendix 10e - 06202 - Unit 2 Diesel Fuel Oil Storage Tank Room
  • Appendix 10f - 06209 - Unit 1 Steam Tunnel Embedded Floor Drain Pipe
  • Appendix 10g - 06210 - Unit 2 Steam Tunnel Embedded Floor Drain Pipe
  • Appendix 10h - 06211 - Unit 1 Tendon Tunnel 547 foot Embedded Floor Drain Pipe
  • Appendix 10i - 06212 - Unit 2 Tendon Tunnel 547 foot Embedded Floor Drain Pipe
  • Appendix 10j - 06213/14A - Unit 1 East and West Valve Houses
  • Appendix 10k - 06215/16A - Unit 2 East and West Valve Houses Each of the Appendixes listed above are stand-alone Release Records for the areas specified.

Table 26 below provides a summary of the FSS results from each. Specifics of the FSS performed in each are provided in each applicable Release Record.

The surface DCGL calculations for the Turbine Building basement accounted for the activity in the Circulating Water Intake Pipes and Circulating Water Discharge Tunnels by summing the surface areas of the connected structures and using the summed areas for the DCGL calculation. The results of the FSS of the Circulating Water Intake Pipes are presented in the Release Record for the Crib House/Forebay; however, the Circulating Water Intake Pipes are also connected to the Turbine Building basement and therefore, the Intake Pipe surface area is also added to the Turbine Building basement. The activity in the Circulating Water Intake Pipes is conservatively assumed to be in both basements simultaneously. The summary of the results of the FSS performed on the Circulating Water Intake Pipe (documented in the Release Record for the Crib House/Forebay) is also presented in Table 26.

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Table 26 - Summary of Final Status Surveys Performed in Ancillary Areas and in Embedded Piping within the Turbine Building Basement Survey Unit Description Area Class No. of Measure ments Mean Concentrations OpSOF Mean BcSOF Dose Co-60 Cs-134 Cs-137 Ni-63 Sr-90 m2 (pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

(pCi/m2)

Mean Max (mrem/yr) 06105B TB 560 foot Embedded Drains 238 3

134 9.73E+03 1.07E+02 8.00E+05 1.76E+06 1.60E+03 0.011 0.028 0.001 0.011 06201 Unit1 570 foot DG Rooms 813 1

51 1.17E+04 3.67E+04 1.25E+04 2.11E+06 2.49E+01 0.054 0.177 0.004 0.102 06202 Unit 2 570 foot DG Rooms 813 1

51 1.51E+04 1.18E+04 2.89E+04 2.72E+06 5.78E+01 0.043 0.228 0.004 0.091 06213 Unit 1 East Valve Room 304 1

26 1.50E+04 3.67E+04 6.86E+05 2.70E+06 1.37E+03 0.448 4.213 0.127 3.186 06214 Unit 1 West Valve Room 304 1

26 1.60E+04 4.40E+04 3.20E+05 2.90E+06 6.40E+02 0.239 1.817 0.053 1.324 06215 Unit 2 East Valve Room 240 3

20 1.91E+04 4.58E+04 6.91E+04 3.45E+06 1.38E+02 0.096 0.327 0.008 0.205 06216 Unit 2 West Valve Room 240 3

20 1.77E+04 4.08E+04 9.95E+04 3.20E+06 1.99E+02 0.109 0.304 0.009 0.231 06107 Unit 1 Tendon Buttress Pits 1596 3

7 4.95E+03 1.44E+03 6.95E+03 8.92E+05 1.39E+01 0.011 0.034 0.001 0.023 06108 Unit 2 Tendon Buttress Pits 1596 3

6 2.47E+03 5.35E+03 5.32E+03 4.46E+05 1.06E+01 0.010 0.022 0.001 0.021 06211 Unit 1 Tendon Tunnel 547 foot Embedded Floor Drain Pipe 51 3

58 1.11E+04 1.21E+02 9.08E+05 2.00E+06 1.82E+03 0.018 0.074 0.000 0.009 06212 Unit 2 Tendon Tunnel 547 foot Embedded Floor Drain Pipe 44 3

44 8.23E+03 8.95E+01 6.74E+05 1.49E+06 1.35E+03 0.014 0.016 0.000 0.007 06209 Unit 1 Steam Tunnel Embedded Floor Drain Pipe 47 3

68 3.80E+04 4.13E+02 3.11E+06 6.86E+06 6.23E+03 0.007 0.018 0.001 0.020 06210 Unit 2 Steam Tunnel Embedded Floor Drain Pipe 46 3

60 1.19E+04 1.29E+02 9.73E+05 2.15E+06 1.95E+03 0.002 0.003 0.000 0.006 08102 Unit 1 and Unit 2 Circulating Water Intake Pipe 4412 3

4 8.99E+03 5.86E+02 7.86E+02 1.62E+06 1.57E+00 0.002 0.006 0.001 0.018

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The activity in the Circulating Water Intake Pipes, Circulating Water Discharge Tunnels, Circulating Water Discharge Pipes, Buttress Pits/Tendon Tunnels, Diesel Generator Rooms and Valve Houses are included with Turbine Building through the DCGL calculation. The area-weighted mean of the measurements taken during FSS in these survey units will be added to the mean of the Turbine Building results. The entire surface areas will be included in the area-weighted average calculation.

The process for calculating the combined basement surface dose from each of the survey units and the calculation method is provided below. Table 27 lists the surface survey units that contribute to the Turbine Building basement.

Table 27 - Surface Survey Units Contributing to the Turbine Building Basement Basement Surface Survey Unit 1 Surface Survey Unit 2 Surface Survey Unit 3 Surface Survey Unit 4 Surface Survey Unit 5 Surface Survey Unit 6 Surface Survey Unit 7 Turbine All walls and floors Circulating Water Discharge Tunnel Circulating Water Intake Pipe (1)

Buttress Pits/

Tendon Tunnels(1)

Circulating Water Discharge Pipe (1)

Unit 1 and Unit 2 Diesel Generator Rooms Unit 1 and Unit 2 Valve Houses (1) Judgmental measurements only - Circulating Water Intake Pipe, Circulating Water Discharge Pipe and Buttress Pits/Tendon Tunnels are not survey units.

After passing the Sign Test, the mean dose contribution for the multiple surface survey units in the Turbine Building basement were determined on an area-weighted basis. The total basement area used in the weighted average calculation is the adjusted surface area used to calculate the DCGLs in LTP Chapter 6, section 6.6.8. The adjusted areas used for the DCGL calculations for the Turbine Building, and applied in the weighted average calculation of total basement surface dose is 27,135 m2, which is reproduced from Chapter 6, section 6.6.8.1, Table 6-23.

The area-weighted BcSOF for basements that have dose contributions from multiple surface survey units was calculated in accordance with Equation 5. For the Circulating Water Discharge Tunnels, Circulating Water Intake Pipe, Circulating Water Discharge Pipe and Buttress Pits/Tendon Tunnels, the SOFBi,B used in Equation 5 is the mean of the judgmental measurements that were taken.

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Equation 5

,=,

=1 where:

SOFB,B

=

total surface SOF including all surface survey units in basement (B)

SASUi,B

=

surface area of survey unit (i) in basement (B)

SAAdjust,B

=

adjusted surface area for DCGL calculation (LTP Chapter 5, Table 5-23) for basement (B)

SOFBi,B

=

SOFB for survey unit (i) in basement (B)

8.

QUALITY CONTROL In compliance with ZS-LT-01, replicate measurements were performed on 5% of the survey locations chosen at random. Three (3) replicate measurements were taken, 1 in the Turbine Building basement, 1 in the Steam Tunnel and 1 in the Circulating Water Discharge Tunnel.

Using the acceptance criteria specified ZS-LT-01, Quality Assurance Project Plan (QAPP) for Characterization and Final Status Survey, there was acceptable agreement between the replicate and original readings. Refer to Attachment 4 for quality control analysis results.

9.

INVESTIGATIONS AND RESULTS When FSS of the Turbine Building basement was performed in March of 2016, it was performed at risk in accordance with the initial version of the LTP, which was not approved.

The initial analysis of the Turbine Building basement and Circulating Water Discharge Tunnel FSS data was directly compared against the BILs from the draft LTP to determine the SOF of individual measurements. When compared against the BILs, all measurements taken for the FSS of these three survey units were less than a SOF of 0.5. Consequently, no investigations were required or performed at the time the survey was performed. However, when the measurement results were compared against the OpDCGLs from the approved Revision 2 of the LTP, several measurements exceeded an OpSOF of 0.5 and several measurements exceeded an OpSOF of 1. In accordance with LTP Chapter 5, section 5.6.4.6, as these survey units were classified as Class 3, an investigation should have been performed and an assessment made to determine if reclassification was warranted. This was not accomplished. By the time this discrepancy was identified, the Turbine Building basement void had been completely backfilled and additional investigations were not possible. It should be noted that, with the exception of the 2 measurements taken under the Unit 2 Down-comer in the Unit 2 Discharge Tunnel, all measurements were less that a BcSOF of 0.5 when compared against the BcDCGLs. The BcSOF for the two measurements in the Unit 2 Discharge Tunnel were less than 1.

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10.

REMEDIATION AND RESULTS Historically, no radiological remedial action as described by MARSSIM Section 5.4 was performed in these survey units prior to or as a result of the FSS. Chapter 4 of the ZSRP LTP determined that remediation beyond that required to meet the release criteria is unnecessary and that the remaining residual radioactivity was ALARA.

11.

CHANGES FROM THE SURVEY PLAN There were no addendums to the FSS plans.

12.

DATA QUALITY ASSESSMENT (DQA)

In accordance with procedure ZS-LT-300-001-004, Final Status Survey Data Assessment (Reference 15), the DQOs, sample design, and data were reviewed for completeness, accuracy, and consistency. Documentation was complete and legible. The FSS units were properly classified. All measurement results were individually reviewed and validated. The number of measurements was sufficient to meet the areal coverage requirements for accessible surfaces.

The instrumentation used to perform the FSS were in calibration, capable of detecting the activity with an adequate MDC and successfully response checked prior to and following use.

An adequate number of replicate measurements were taken and the results met the acceptance criteria as specified in the QAPP.

The Sign Test (Attachment 3) was performed on the data and compared to the original assumptions of the DQOs. The evaluation of the Sign Test results clearly demonstrates that the survey units pass the unrestricted release criteria, thus, the null hypothesis is rejected.

The preliminary data review consisted of calculating basic statistical quantities (e.g., mean, median, standard deviation). All data was considered valid including negative values, zeros, values reported below the MDC, and values with uncertainties greater than 2 standard deviations. The mean and median values for each ROC were well below the respective OpDCGLs. Also, the retrospective power curve showed that a sufficient number of samples were collected to achieve the desired power. Therefore, the survey units meet the unrestricted release criteria with adequate power as required by the DQOs.

The data for Co-60 and Cs-137 is represented graphically through a frequency plot and a quantile plot. All graphical representations are provided in Attachment 5.

13.

ANOMALIES No anomalies were observed during the performance or analyses of the survey.

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14.

COMPLIANCE EQUATION There are four distinct source terms for the end-state at Zion: backfilled basements, soil, buried piping and groundwater. Demonstrating compliance with the dose criterion requires the summation of dose from the four source terms (see Equation 6-11 from LTP Chapter 6, section 6-17).

The final compliance dose will be calculated using Equation 6-11 after FSS has been completed in all survey units. The results of the FSS performed for each FSS unit will be reviewed to determine the maximum dose from each of the four source terms (e.g., basement, soil, buried pipe and existing groundwater if applicable) using the mean BcSOF of FSS results plus the dose from any identified elevated areas. The compliance dose must be less than 25 mrem/yr.

The dose contribution from each ROC is accounted for using the BcSOF to ensure that the total dose from all ROC does not exceed the dose criterion.

The term for each basement includes the dose contributions from wall and floor surfaces within the basement, the dose contribution from embedded pipe within the basement, the dose contribution from penetrations within the basement and the dose contribution from concrete fill in the basement when clean concrete debris was used as fill. Each (structural surfaces, embedded pipe and penetrations) are surveyed separately during FSS. The dose from clean concrete fill is predetermined in accordance with LTP Chapter 5, Table 5-21, which is conservatively based on a maximum allowable MDC of 5,000 dpm/100cm2. The dose from fill assigned to the Turbine Building basement is 1.58 mrem/yr, which equates to a SOF of 0.063.

Basement surface area adjustments (i.e., increases) were applied to the structure surface DCGL calculation for certain basements to ensure that the DCGLs accounted for the contribution of residual radioactivity from basements/structures that cannot, on their own, support a water supply well but were hydraulically connected to a basement that could support a well. One of these structures is the Circulating Water Intake Pipes. The surface area adjustments resulted in lowering the DCGL concentrations (pCi/m2) in the Crib House/Forebay by requiring the allowable total activity to be uniformly distributed over the larger, combined surface areas.

The activity in the Circulating Water Intake Pipes is included in both the Crib House/Forebay and the Turbine Building Basement. The Intake Pipe was grouted which essentially eliminated the hydraulic connections. However, in calculating the BcDCGLs, the hydraulic connections to the Intake Pipe were assumed to be fully regained in the future after degradation of the isolation barriers and grout.

The BcDCGLs for the Turbine Building Basement account for the activity in the Circulating Water Intake Pipes, Circulating Water Discharge Tunnels, Circulating Water Discharge Pipes, Buttress Pits/Tendon Tunnels, Diesel Generator Rooms and Valve Houses by summing the surface areas. In accordance with LTP Chapter 6, Table 6-23, the combined summed surface area of the Turbine Building is 27,135 m2. The areas for each of the surface areas within the

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Turbine Building are provided in Table 26. Area weighting using Equation 5 was used to sum for the mean residual activity in the Turbine Building structure (BcSOF=0.021), Circulating Water Discharge Tunnels (BcSOF=0.127), Unit 1 East Valve Room (BcSOF=0.127), Unit 1 West Valve Room (BcSOF=0.053), Circulating Water Discharge Pipes (BcSOF=0.012), Unit 1 Diesel Generator Room (BcSOF=0.004), Unit 2 Diesel Generator Room (BcSOF=0.004), Unit 2 East Valve Room (BcSOF=0.008), Unit 2 West Valve Room (BcSOF=0.009), Unit 1 Tendon Buttress Pit (BcSOF=0.001), Unit 2 Tendon Buttress Pit (BcSOF=0.001) and the Circulating Water Intake Pipes (BcSOF=0.001). The area weighted mean BcSOF for the Turbine Building was calculated as follows using Equation 6.

Equation 6

14864 27135(0.021)+

4868 27135(0.127)+

304 27135(0.127)+

304 27135(0.053)+

1075 27135(0.012)+

813 27135(0.004)+

813 27135(0.004)+

240 27135(0.008)+

240 27135(0.009)+

1596 27135(0.001)+

1596 27135(0.001)+

4412 27135(0.001)= 0.037 The area weighted mean BcSOF for the Turbine Building basement FSS unit is 0.037. This equates to a dose of 0.937 mrem/yr. The adjusted mean BcSOF for the Turbine Building is then used in the following equation to calculate BcSOFBASEMENT for the Turbine Building.

Equation 7

= + + +

where:

BcSOFBASEMENT

=

BcSOF (mean of FSS systematic results plus the dose from any identified elevated areas) for backfilled basements BcSOFB

=

BcSOF for structural survey unit(s) within the basement (mean of FSS systematic results plus the dose from any identified elevated areas)

BcSOFEP

=

BcSOF for embedded pipe survey unit(s) within the basement (mean of FSS systematic results plus the dose from any identified elevated areas)

BcSOFPN

=

BcSOF for penetration survey unit(s) within the basement (mean of FSS systematic results plus the dose from any identified elevated areas)

BcSOFCF

=

BcSOF for clean concrete fill (if applicable) based on maximum MDC during Unrestricted Release Survey (URS)

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In accordance with TSD 14-016, there were 11 penetrations (T91, T92, T93, T94, T96, T97, T98, T99, T100, T101 and T104) that accessed the exterior C wall of the Turbine Building basement (east wall) between the 585 foot and the 586 foot elevation. All the penetrations on the east wall of the Turbine Building were concentrated in and around the basement Oil Room at the centerline of the building. As all the penetrations in question were shallow in relation to the final end-state grade (588 foot elevation), the pipes were all removed during decommissioning, and the openings in the wall were grouted. Penetrations also interfaced between the Turbine Building and the Auxiliary Building, primarily through the G wall but also through the north and south walls into the Unit 1 and Unit 2 Steam Tunnels, as well as both Unit 1 and Unit 2 Containments, through the Unit 1 and Unit 2 Main Steam Valve Houses.

LTP Chapter 6, section 6.4.5 states, The dose from penetrations is summed with the dose from the wall and floor surfaces of both basements that the penetration interface. The mean BcSOF for the Auxiliary Building penetrations was 0.002 and, the mean BcSOF for the Unit 1 and Unit 2 Containments were 0.059 and 0.008 respectively. The mean BcSOF for each penetration survey unit were summed for a value of 0.069, which was used as the BcSOFPN variable for the BcSOFBASEMENT calculation for the Turbine Building.

The value for embedded pipe in the Turbine Building is a summation of the BcSOF for the 560 foot elevation floor drains, the Unit 1 and Unit 2 Steam Tunnel floor drains and the Unit 1 and Unit 2 Tendon Tunnel floor drains. These values are listed in Table 26 and sum for a BcSOF value of 0.0023.

The BcSOFBASEMENT value for the Turbine Building is then derived as follows; Equation 8

= 0.037 + 0.003 + 0.069 + 0.063 = 0.173 The BcSOFBASEMENT for the Turbine Building basement is 0.173. This dose fraction equates to a dose of 4.317 mrem/yr TEDE to an AMCG from residual radioactivity in the Turbine Building basement.

15.

CONCLUSION Survey unit 06100, Turbine Building, survey unit 09200, Circulating Water Discharge Tunnels and survey unit 06105A, Unit 1 and Unit 2 Circulating Water Discharge Pipe have met the DQOs of their respective FSS plans. The ALARA criteria as specified in Chapter 4 of the LTP were achieved. The EMC is not applicable to structural surfaces, and remediation was not required.

All identified ROC were used for statistical testing to determine the adequacy of the survey unit for FSS. Evaluation of the data shows that none of the mean ROC concentration values

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exceeded the OpDCGL; therefore, in accordance with the LTP Section 5.10, the survey unit meets the release criterion.

The sample data passed the Sign Test. The null hypothesis was rejected. The Retrospective Power Curve showed that adequate power was achieved. The survey units were properly classified.

The dose contribution from structural surfaces in survey unit 06100, Turbine Building, is 0.937 mrem/year TEDE, based on the average concentration of the ROC in samples used for non-parametric statistical sampling as well as measurements taken in the Circulating Water Intake Pipes, Circulating Water Discharge Tunnels, Circulating Water Discharge Pipes, Buttress Pits/Tendon Tunnels, Diesel Generator Rooms and Valve Houses on an area-weighted basis.

The dose from penetrations that interfaced with the Turbine Building is 1.727 mrem/yr TEDE, the dose from embedded pipe in the Turbine Building is 0.037 mrem/year TEDE and the dose from clean fill is 1.580 mrem/yr. The total dose attributed to the Turbine Building as a summation of all dose components is 4.317 mrem/yr.

Survey units 06100, Turbine Building, 09200, Circulating Water Discharge Tunnels and 06105A, Unit 1 and Unit 2 Circulating Water Discharge Pipe are acceptable for unrestricted release.

16.

REFERENCES

1.

ZionSolutions ZS-LT-300-001-005, Final Status Survey Data Reporting

2.

Zion Station Restoration Project License Termination Plan

3.

ZionSolutions ZS-LT-300-001-001, Final Status Survey Package Development

4.

NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual

5.

ZionSolutions TSD 14-016, Description of Embedded Piping, Penetrations, and Buried Pipe to Remain in Zion End State

6.

ZionSolutions procedure ZS-LT-300-001-002, Survey Unit Classification

7.

Zion Station Historical Site Assessment

8.

ZionSolutions procedure ZS-LT-400-001-001, Unconditional Release of Material, Equipment and Secondary Structures

9.

ZionSolutions TSD 11-001, Technical Support Document for Potential Radionuclides of Concern During the Decommissioning of the Zion Station

10.

ZionSolutions TSD 14-019, Radionuclides of Concern for Soil and Basement Fill Model Source Terms

11.

ZionSolutions TSD 17-004, Operational Derived Concentration Guideline Levels for Final Status Survey

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12.

ZionSolutions procedure ZS-LT-01, Quality Assurance Project Plan (for Characterization and FSS)

13.

ZionSolutions procedure ZS-LT-300-001-003, Isolation and Control for Final Status Survey

14.

ZionSolutions TSD 14-022, Use of In-Situ Gamma Spectroscopy for Final Status Survey of End State Structures

15.

ZS-LT-300-001-004, Final Status Survey Data Assessment

17.

ATTACHMENTS

1. - Maps
2. - ISOCS Geometry
3. - Sign Test
4. - QC Measurement Assessment
5. - Graphical Presentations
6. - ISOCS Reports

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ATTACHMENT 1 MAPS

FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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Figure 6 - Turbine Building Basement Random and Judgmental Measurements

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Figure 7 - Unit 1 and Unit 2 Steam Tunnels Random and Judgmental Measurements

FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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Figure 8 - Unit 1 and Unit 2 Circulating Water Discharge Tunnels Judgmental Measurements

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Figure 9 - Unit 1 and Unit 2 Circulating Water Discharge Pipe Judgmental Measurements

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ATTACHMENT 2 ISOCS GEOMETRY

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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ATTACHMENT 3 SIGN TEST

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Survey Area 06000 Survey Area Turbine Building Survey Unit 06100 Survey Unit Basement Surfaces Classification 3

Type I Error 0.05 Number of Measurements 28 SOF (Ws) 1-Ws Sign 1

0.036 0.96

-1 2

0.041 0.96

+1 3

0.013 0.99

+1 4

0.040 0.96

+1 5

0.041 0.96

+1 6

0.037 0.96

+1 7

0.035 0.96

+1 8

0.019 0.98

+1 9

0.037 0.96

+1 10 0.039 0.96

+1 11 0.041 0.96

+1 12 0.042 0.96

+1 13 0.042 0.96

+1 14 0.036 0.96

+1 15 0.444 0.56

+1 16 1.346 (0.35)

-1 17 0.429 0.57

+1 18 0.475 0.52

+1 19 0.434 0.57

+1 20 0.269 0.73

+1 21 0.451 0.55

+1 22 0.378 0.62

+1 23 0.400 0.60

+1 24 0.396 0.60

+1 25 0.471 0.53

+1 26 0.418 0.58

+1 27 0.420 0.58

+1 28 0.043 0.96

+1 Number of positive differences (S+)

27 Critical Value 18 The Survey Unit MEETS the Acceptance Criteria

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ATTACHMENT 4 QC MEASUREMENT ASSESSMENT

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Replicate Measurement Assessment Survey Unit #

06100 Survey Unit Name Turbine Building Structural Surfaces Sample Plan #

B3-06100A-S Sample

Description:

Comparison of systematic and QC ISOCS measurements at location #9. The standard measurement ID is B3-06100A-FRWC-009-GD. The comparison measurements ID is B3-06100A-FQWC-009-GD.

STANDARD COMPARISON ROC Activity Value Standard Error Resolution Agreement Range Activity Value Standard Error Comparison Ratio Acceptable (Y/N)

K-40 7.88E+05 1.72E+05 5

0.5-2.0 8.44E+05 1.82E+05 0.9 Y

Comments/Corrective Actions: There was acceptable agreement between the standard measurement and the replicate measurement. Based on the professional judgment of the Radiological Engineer, the same conclusion was reached for each measurement. No further action is necessary.

Table is provided to show acceptance criteria used to assess split samples.

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Replicate Measurement Assessment Survey Unit #

06000 Survey Unit Name Turbine Building Steam Tunnel Sample Plan #

B3-06100B-S Sample

Description:

Comparison of systematic and QC ISOCS measurements at location #11. The standard measurement ID is B3-6100B-FRWC-011-GD. The comparison measurements ID is B3-6100B-FQWC-011-GD.

STANDARD COMPARISON ROC Activity Value Standard Error Resolution Agreement Range Activity Value Standard Error Compariso n Ratio Acceptable (Y/N)

K-40 1.81E+07 2.58E+06 7

0.5-2.0 1.80E+07 2.64E+06 1.0 Y

Comments/Corrective Actions: There was acceptable agreement between the standard measurement and the replicate measurement. Based on the professional judgment of the Radiological Engineer, the same conclusion was reached for each measurement. No further action is necessary.

Table is provided to show acceptance criteria used to assess split samples.

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Replicate Measurement Assessment Survey Unit #

09000 Survey Unit Name Circ. Water Discharge Tunnel Sample Plan #

B3-09200B-S Sample

Description:

Comparison of systematic and QC ISOCS measurements at location #9. The standard measurement ID is B3-09200B-FRCC-009-GD. The comparison measurements ID is B3-09200B -FQCC-009-GD.

STANDARD COMPARISON ROC Activity Value Standard Error Resolution Agreement Range Activity Value Standard Error Compariso n Ratio Acceptable (Y/N)

K-40 8.88E+05 2.14E+05 4

0.5-2.0 8.90E+05 1.93E+05 1.0 Y

Comments/Corrective Actions: There was acceptable agreement between the standard measurement and the replicate measurement. Based on the professional judgment of the Radiological Engineer, the same conclusion was reached for each measurement. No further action is necessary.

Table is provided to show acceptance criteria used to assess split samples.

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ATTACHMENT 5 GRAPHICAL PRESENTATIONS

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Figure 10 - Quantile Plot for Co-60 Concentrations

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Figure 11 - Quantile Plot for Cs-137 Concentrations

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Figure 12 - Histogram for Co-60 Concentrations

FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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Figure 13 - Histogram for Cs-137 Concentrations

FSS RELEASE RECORD TURBINE BUILDING BASEMENT SURVEY UNIT 06100

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Figure 14 - Restrospective Power Curve

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ATTACHMENT 6 ISOCS REPORTS (See Separate ISOCS Reports File)

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