ML19295G855

From kanterella
Jump to navigation Jump to search
Revised Final Status Survey (FSS) Report - Phase 2, Release Record - Unit 2 Steam Tunnel Embedded Floor Drain Pipe Survey Unit 06210
ML19295G855
Person / Time
Site: Zion  File:ZionSolutions icon.png
Issue date: 09/01/2019
From: Graham J
ZionSolutions
To:
Office of Nuclear Material Safety and Safeguards
Shared Package
ML19295G627 List:
References
ZS-2019-0090
Download: ML19295G855 (35)
v • d • e


Text

ZION STATION RESTORATION PROJECT FINAL STATUS SURVEY RELEASE RECORD UNIT 2 STEAM TUNNEL EMBEDDED FLOOR DRAIN PIPE SURVEY UNIT 06210

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 PREPARED BY / DATE: J. Graham 2019-09-01 Radiological Engineer REVIEWED BY / DATE: P. Giza 2019-09-01 Radiological Engineer APPROVED BY / DATE: D. Wojtkowiak 2019-09-01 C/LT Manager

[2]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 TABLE OF CONTENTS

1. EXECUTIVE

SUMMARY

....................................................................................................6

2. SURVEY UNIT DESCRIPTION ..........................................................................................6
3. CLASSIFICATION BASIS ...................................................................................................6
4. DATA QUALITY OBJECTIVES (DQO) ............................................................................7
5. SURVEY DESIGN .................................................................................................................9
6. SURVEY IMPLEMENTATION ........................................................................................15
7. SURVEY RESULTS ............................................................................................................17
8. QUALITY CONTROL ........................................................................................................19
9. INVESTIGATIONS AND RESULTS ................................................................................19
10. REMEDIATION AND RESULTS......................................................................................19
11. CHANGES FROM THE SURVEY PLAN ........................................................................19
12. DATA QUALITY ASSESSMENT (DQA) .........................................................................19
13. ANOMALIES .......................................................................................................................20
14. CONCLUSION .....................................................................................................................20
15. REFERENCES .....................................................................................................................20
16. ATTACHMENTS .................................................................................................................21 ATTACHMENT 1 - FIGURES ......................................................................22 ATTACHMENT 2 - SAMPLE DATA ...........................................................24 ATTACHMENT 3 - SIGN TEST ...................................................................28 ATTACHMENT 4 - QC SAMPLE ASSESSMENT .....................................30 ATTACHMENT 5 - GRAPHICAL PRESENTATIONS.............................32 LIST OF TABLES Table 1 - Dose Significant Radionuclides and Mixture................................................................... 8 Table 2 - Modified Base Case and Operational DCGLs ................................................................. 9 Table 3 - Surrogate Ratios ............................................................................................................. 10 Table 4 - Surrogate Base Case and Operational DCGLs ............................................................... 11 Table 5 - Typical FSS Instrument Detection Sensitivities............................................................. 14 Table 6 - Synopsis of Survey Design ............................................................................................ 15 Table 7 - Survey Data Collected .................................................................................................... 16 Table 8 - Instrument and Detector ................................................................................................. 17 Table 9 - Unit 2 Steam Tunnel Embedded Floor Drain Pipe - Measurement Results .................. 18

[3]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 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 cpm Counts per Minute dpm Disintegrations per Minute DQA Data Quality Assessment DQO Data Quality Objective DCGL Derived Concentration Guideline Level EMC Elevated Measurement Comparison FSS Final Status Survey HTD Hard-to-Detect IC Insignificant Contributor LTP License Termination Plan MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual OpDCGL Operational Derived Concentration Guideline Level OpSOF Operational Sum of Fractions QAPP Quality Assurance Project Plan QC Quality Control ROC Radionuclides of Concern SOF Sum of Fractions TEDE Total Effective Dose Equivalent

[4]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 UCL Upper Confidence Level ZNPS Zion Nuclear Power Station ZSRP Zion Station Restoration Project

[5]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210

1. EXECUTIVE

SUMMARY

This Final Status Survey (FSS) Release Record for survey unit 06210, the Unit 2 Steam Tunnel Embedded Floor Drain 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).

Final Status Survey Sample Plan S3-06210AF was 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).

Final Status Survey 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. The Unit 2 Steam Tunnel Embedded Floor Drain Pipe was classified as MARSSIM Class 3.

The Unit 2 Steam Tunnel Embedded Floor Drain Pipe was surveyed with a Ludlum 2350-1 Data Logger paired with a 44-159 gamma detector. Following excavation of the northeast corner of the Steam Tunnel, the drain piping was accessed through cleanout M205. The detector was able to access 120 feet of the pipe from this access point.

Readings were taken at 2-foot intervals to allow enough readings to provide for the 10%

coverage requirement for a Class 3 survey unit. The total length of this piping system was 474 linear feet.

For the FSS of the Unit 2 Steam Tunnel Embedded Floor Drain Pipe, 60 readings were obtained. All of the readings were below an Operational Sum of Fractions (OpSOF) of 0.5 when compared against the Operational DCGL for embedded pipe (OpDCGLEP) with the mean OpSOF reading of 0.002. The mean Base Case SOF (BcSOF), when compared to the Base Case DCGL for embedded pipe (BcDCGLEP) was 0.000, which results in the dose calculated for this survey unit of 0.006 mrem/yr.

2. SURVEY UNIT DESCRIPTION The Unit 2 Steam Tunnel Embedded Floor Drain Pipe consists of a 4-inch diameter pipe that is 474 linear feet in length. The floor of the tunnel is at 568 foot elevation, with the drain piping embedded in the concrete approximately 2 feet deep.
3. CLASSIFICATION BASIS Survey unit 06210 was classified in accordance with ZionSolutions procedure ZS-LT-300-001-002, Survey Unit Classification (Reference 5).

[6]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 The Turbine Building was initially classified as a Class 2 structure by the Zion Station Historical Site Assessment (HSA) (Reference 6). LTP Section 5.5.2.1.2 changed the classification of the Turbine Building basement from Class 2 to Class 3. The LTP states The FSS units for the basements of the Turbine Building, the Crib House/Forebay, WWTF and the Circulating Water Discharge Tunnels are designated as Class 3 as defined in MARSSIM, section 2.2 in that the FSS units are expected to contain levels of residual activity at a small fraction of the DCGLs, based on site operating history and previous radiation surveys.

4. DATA QUALITY OBJECTIVES (DQO)

Final Status Survey planning and design hinges on coherence with the 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 will be 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 unit 06210 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).

LTP Chapter 6, section 6.5.2 discusses the process used to derive the Radionuclides of Concern (ROC) for the decommissioning of Zion Nuclear Power Station (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.

The residual radioactivity in embedded piping located below the 588 foot grade that will remain and be subjected to FSS is discussed in LTP Chapter 2, section 2.3.3.7 and TSD

[7]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 14-016, Description of Embedded Piping, Penetrations, and Buried Pipe to Remain in Zion End State (Reference 7). The DCGLs for embedded piping are listed in LTP Chapter 5, sections 5.2.7 and 5.2.8.

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 reasonable conservative mixture to apply to the Unit 2 Steam Tunnel Embedded Floor Drain Pipe for FSS planning and implementation. Table 1 reproduces the ROC from LTP Chapter 5, Table 5-2.

Table 1 - Dose Significant Radionuclides and Mixture Auxiliary Building Radionuclide  % 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 FSS is conducted on the interior surfaces of embedded piping to demonstrate that the concentrations of residual activity are equal to or below DCGLs corresponding to the dose criterion in 10CFR20.1402 (DCGLEP). DCGLEP were calculated for each of the remaining embedded pipe systems. The DCGLEP values for the Steam Tunnel Drain embedded pipe system from LTP Chapter 6, section 6.13 are referred to as BcDCGLs.

At ZNPS, compliance is demonstrated through the summation of dose from four distinct source terms for the end-state (basements, soils, buried pipe and groundwater). 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 per year to an Average Member of the Critical Group (AMCG). To ensure that the summation of dose from each source term is 25 mrem/year or less after all FSS is completed, the BcDCGLs are reduced based on an expected, or a priori, fraction of the 25 mrem/year 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

[8]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 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 ZionSolutions TSD 17-004, Operational Derived Concentration Guideline Levels for Final Status Survey (Reference 8).

The BcDCGLs and OpDCGLs for the Unit 2 Steam Tunnel Embedded Floor Drain Pipe are listed in Tables 5-11 and 5-12 of the LTP.

License Termination Plan Chapter 5, section 5.5.5 discusses the alternate drilling spoils resident farmer scenario. The dose for the Unit 2 Steam Tunnel Embedded Floor Drain Pipe in this scenario is calculated to be 71.16 mrem/year using the maximum hypothetical activity that could be allowed to remain. As a conservative measure, the BcDCGLs were adjusted by a factor of 2.89 (71.16/25), which will reduce the hypothetical maximum dose to 25 mrem/year.

The Modified BcDCGLs and the OpDCGLs are reproduced in the Table 2.

Table 2 - Modified Base Case and Operational DCGLs Modified Base Case Operational Radionuclide Embedded Pipe DCGL Embedded Pipe DCGL pCi/m2 (1) pCi/m2 Co-60 1.41E+10 1.63E+09 Cs-134 3.19E+09 3.69E+08 Cs-137 4.22E+09 4.88E+08 Ni-63 4.36E+11 5.04E+10 Sr-90 1.55E+08 1.79E+07 (1) Values represent BcDCGLs from Table 5-11 for the Steam Tunnel reduced by a factor of 2.89.

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 Final Status Survey Package Development.

During FSS, concentrations for Hard-to-Detect (HTD) ROC Ni-63 and Sr-90 are inferred using a surrogate approach. Cs-137 is the principle surrogate radionuclide for Sr-90 and Co-60 is the principle surrogate radionuclide for Ni-63. The mean, maximum and 95%

Upper Confidence Level (UCL) of the surrogate ratios for concrete core samples taken in the Auxiliary Building basement were calculated in ZionSolutions TSD 14-019, Radionuclides of Concern for Soil and Basement Fill Model Source Terms (Reference

[9]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210

9) and are presented in Table 3. The maximum ratios will be used in the surrogate calculations during this FSS. Equations 2 through 5 show the results of the calculations.

The results of the surrogate calculations are listed in Table 4.

Table 3 - Surrogate Ratios Auxiliary Building Ratios Mean Max 95%UCL Ni-63/Co-60 44.143 180.450 154.632 Sr-90/Cs-137 0.001 0.002 0.002 The equation for calculating a surrogate DCGL is as follows:

Equation 1 1

=

1 2 3

+ + +

2 3 Using the Base Case and Operational DCGLs presented in Table 2 and the maximum ratios from Table 3, the following surrogate calculations were performed:

Equation 2 (Cs-137 Surrogate BcDCGL) 1 (137) = = 4.0009 /2 1 0.002

+

4.2209(137) 1.5508(90)

Equation 3 (Cs-137 Surrogate OpDCGL) 1 (137) = = 4.6308 /2 1 0.002

+

4.8808(137) 1.7907(90)

Equation 4 (Co-60 Surrogate BcDCGL) 1 (60) = = 2.0609 /2 1 180.45

+

1.4110(060) 4.3611(63)

Equation 5 (Co-60 Surrogate OpDCGL) 1 (60) = = 2.3808 /2 1 180.45

+

1.639(060) 5.0410(63)

[10]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Table 4 - Surrogate Base Case and Operational DCGLs Base Case Operational Radionuclide Embedded Pipe DCGL Embedded Pipe DCGL pCi/m2 pCi/m2 Co-60 2.06E+09 2.38E+08 Cs-134 3.19E+09 3.69E+08 Cs-137 4.00E+09 4.63E+08 The survey design calculated a gross-gamma OpDCGL of 1.75E+08 pCi/m2. The Action Level used for the surveys for this survey unit was 50% of this value: 8.74E+07 pCi/m2.

The equation for calculating Gross Activity is as follows:

Equation 6 1

= f1 f2 fN

+ +

DCGL1 DCGL2 DCGLN The normalized gamma mixture was applied to the OpDCGLs for the gamma-emitting nuclides in Table 2 in the following equation:

Equation 7 (Gross Gamma Activity DCGL) 1

= 0.98780 0.01207 0.00013

= 4.9208 /2

+ +

4.8808 1.6309 3.6908 The Gross Activity DCGL was then used in the surrogate equation using the surrogate ratios from Table 3:

Equation 8 (Surrogate Gross Gamma Activity DCGL) 1

() = = 1.7508 /2 1 180.45 0.002

+ +

4.9208 5.0410(63) 1.7907(90)

[11]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 The Unit 2 Steam Tunnel Embedded Floor Drain Pipe is Class 3 embedded pipe. For the survey of pipe internal surfaces, areal coverage is achieved by the area of detection for each static measurement taken. Scanning, in the traditional context, is not applicable to the survey of pipe internal surfaces. For the survey of these pipes, the pipe detector was calibrated for the specific geometry of the 4-inch pipes. For a 4-inch Internal Diameter (ID) pipe, each measurement has a calculated Field-of-View (FOV) of 1.05 ft2 (0.097 m2).

The Unit 2 Steam Tunnel Embedded Floor Drain Pipe contains 474 linear feet of 4-inch ID piping, which equates to a surface area of 46.1 m2. The LTP states that a FSS Class 3 survey unit shall have a minimum areal coverage of 10%. Therefore, one measurement was to be collected every 10 linear feet of piping traversed for a total of 47 distinct measurements over the entire accessible pathway of the piping system. For quality control purposes, a minimum of 5% of the measurements collected were to be replicated.

This would require an additional 3 measurements to be collected throughout the length of the accessible surface of the piping system at locations selected at random.

Each static measurement represents the gamma activity in gross Counts per Minute (cpm) for each specific measurement location. This gamma measurement value in cpm was then converted to Disintegrations per Minute (dpm) using an efficiency factor based on the calibration source. The total activity in dpm is then adjusted for the assumed total effective surface area commensurate with the pipe/penetration diameter, resulting in measurement results in units of dpm per m2. Unit conversion converted dpm to units of pCi. The measurement result, in units of pCi/m2, represents a commensurate and conservative gamma surface activity. The total gamma surface activity for each FSS measurement is converted to a gamma measurement result (in units of pCi/m2) for each gamma ROC based on the normalized gamma mixture from Table 1. Concentrations for HTD ROC are inferred using the surrogate approach in accordance with LTP Chapter 5.

Cs-137 is the principle surrogate radionuclide for H-3 and Sr-90. Co-60 is the principle surrogate radionuclide for Ni-63. The maximum ratios from Table 3, which are reproduced from Table 5-15 of the LTP, were used in the surrogate calculations.

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 summation of the dose fractions for each ROC produces an OpSOF for the measurement.

[12]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 To demonstrate that each survey unit satisfies the OpDCGL, the ROC concentration for each systematic measurement taken in the Unit 2 Steam Tunnel Embedded Floor Drain Pipe was divided by its applicable OpDCGLEP to derive an OpSOF for the ROC. The OpSOF for each ROC was then summed to determine the total OpSOF for all ROC that represents the measurement and was used as the summed value (Ws) for performing the Sign Test.

If the OpSOF for a systematic or judgmental measurement exceeded 0.5 in a Class 3 survey unit, then an investigation would be initiated in accordance with LTP Chapter 5, section 5.6.4.6 (Table 5-25). In a Class 3 FSS unit, the result of the investigation could prompt the reclassification of the survey unit (or a portion of the survey unit).

Embedded pipe survey units have a relatively small surface area, which results in OpDCGLs that are higher than the wall/floor OpDCGLs. The reason for this is that the total internal surface area of the embedded pipe survey unit in a given basement is much less than the total wall/floor surface area of the basement containing them. To eliminate the potential for activity levels in embedded pipe that could lead to releases greater than surrounding walls and floors, the following remediation and grouting action levels were applied to measurements of surface activity in embedded pipe.

  • If maximum activity exceeds the BcDCGLEP from LTP Chapter 5, Table 5-11 (SOF

>1), then remediation was performed.

  • If the maximum activity in an embedded pipe exceeded the surface OpDCGLB from LTP Chapter 5, Table 5-4 in the building that contains it, but was below the BcDCGLEP from LTP Chapter 5, Table 5-11, then the embedded pipe was remediated or grouted.
  • If an embedded pipe was remediated and the maximum activity continues to exceed the surface OpDCGLB from LTP Chapter 5, Table 5-4, but is less than the Operational DCGLEP from LTP Chapter 5, Table 5-12, then the embedded pipe was grouted.
  • If the maximum activity was below the surface OpDCGLB from LTP Chapter 5, Table 5-4, then grouting of the pipe was not required.

The instrumentation used for the FSS of the Unit 2 Steam Tunnel Embedded Floor Drain Pipe was the Ludlum Model 2350-1 and the Model 44-159 detector.

[13]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 The instrumentation sensitivities are provided in Chapter 5 of the LTP and are reproduced in Table 5.

Table 5 - Typical FSS Instrument Detection Sensitivities BKGD Typical Typical Count Static MDC Scan MDC Count Instrument Instrument /Detector Radiation BKGD Time (dpm/100 (dpm/100 Time Efficiency (cpm) (1)(2) (min.) cm2) cm2)

(min.)

Ludlum 2350-1/ 44-159 Gamma 1 700 0.024 1 5,250 N/A (1) Typical calibration source used is Cs-137. The efficiency is determined by counting the source with the detector in a fixed position from the source (reproducible geometry). The t value is based on ISO-7503-1 and conditions noted for each detector.

(2) The efficiency varies for the pipe detectors depending on the pipe diameter used. The efficiency used for the table is the average efficiency value for the pipe diameters. The detectors and diameters are: Model 44-159: 2-4 in. dia., Model 44-157: 4-8 in. dia., Model 44-162: 8-12 in. diameter.

The Elevated Measurement Comparison (EMC) did not apply to this survey unit. At 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 compliance with ZS-LT-01, Quality Assurance Project Plan (for Characterization and FSS) (QAPP) (Reference 10), replicate measurements were to be performed on 5%

of the static measurement locations.

[14]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Table 6 - Synopsis of Survey Design Feature Design Criteria Basis Survey Unit Area 46.1 m2 4 in (ID) x 474 ft (length) x Number of Static 47 10% areal coverage, Class 3 Measurements Measurement As needed to obtain sufficient 10% areal coverage, Class 3 Spacing measurements for 10% areal coverage

  • Co 1.63E+09 pCi/m2
  • Cs-134 - 3.69E+08 pCi/m2 Operational DCGLs for Unit 1 and Unit 2 Steam Tunnel Drain DCGLs
  • Cs-137 -4.88E+08 pCi/m2 Embedded Pipe,
  • Ni-63 -5.04E+10 pCi/m2 (LTP Chapter 5, Table 5-12)
  • Sr-90 -1.79E+07 pCi/m2 Gross Gamma DCGL adjusted for HTD HTD ROC Analysis LTP 5.7.1.9 based on the isotopic mixture Measurement

>0.5 Gross Gamma Operational DCGL (LTP Chapter 5, Table 5-25)

Investigation Level Scan Survey Area N/A LTP 5.7.1.9 Coverage replicate measurements will be Quality Control performed on 5% of the static QAPP (QC) measurement locations

6. SURVEY IMPLEMENTATION Survey instructions for this FSS were incorporated into and performed in accordance with FSS Sample Plan S3-06210AF, which was developed in accordance with ZionSolutions procedure ZS-LT-300-001-001, Final Status Survey Package Development. The FSS unit was inspected and controlled in accordance with ZionSolutions procedure ZS-LT-300-001-003, Isolation and Control for Final Status Survey (Reference 11).

Field Logs (ZS-LT-300-001-001 Attachment 14) were used to document field activities and other information pertaining to the performance of the FSS. Daily briefings were conducted to discuss the expectations for job performance and to review safety aspects of the job.

[15]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 The approach used for the radiological survey of the interior surfaces of the Unit 2 Steam Tunnel Embedded Floor Drain Pipe involved the insertion of a 1 x 1 CsI detector that was attached to the See Snake camera system and transported through the pipe to the maximum deployment length, or to a location of drain drop. A simple push-pull methodology was used, whereby the position of the detector in the piping system could be easily determined in a reproducible manner. Footage was tabulated on the See Snake, then measurements were obtained at 2 foot intervals while backing out of the pipe section.

A background value was also determined for the detector/instrument combination to be used prior to deployment. The background value was obtained at the location where the pre-use response check of the instrument was performed. The background value was primarily used to ensure that the detector had not become cross-contaminated by any previous use. Background was not subtracted from any measurement.

Daily prior to use and daily following use, each detector was subjected to an Operational Response Check in accordance with procedure ZS-LT-300-001-006, Radiation Surveys of Pipe Interiors Using Sodium/Cesium Iodide Detectors (Reference 12). The Daily Operational Response Check compared the background response and the response to check sources ranges established for normal background and detector source response to ensure that the detector was working properly.

Surveys of the Unit 2 Steam Tunnel Embedded Floor Drain Pipe were performed on April 30, 2018. The survey was completed in 1 day. The piping was accessed through the Y cleanout position (M205) located in the northeast corner of the Unit 2 Steam Tunnel. The See Snake and detector were inserted 120 feet into the pipe. Because the entire length of the pipe was not available for survey, it was decided to take measurements at 2 foot intervals to obtain sufficient readings to meet the 10% coverage required for the Class 3 survey unit. The Survey Design called for 47 readings to be taken at 10 foot intervals. Table 7 summarizes the data collected:

Table 7 - Survey Data Collected Length # of Measurements Pipe Run Comment Surveyed Taken M205 120 60 3 QC readings taken The instrument and detector used for this survey are presented in Table 8. The instrument and detector were verified to be properly calibrated prior to use.

[16]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Table 8 - Instrument and Detector Instrument/Detector Calibration Due Serial #

Type Date Ludlum 2350-1 304708 05/01/18 Ludlum 44-159 PR327896 05/01/18 Daily prior to use (Pre-Test) and daily upon completion of surveys (Post-Test), response checks were performed in accordance with procedure ZS-LT-300-001-006 for each detector and data logger pairing. In addition, all instruments and detectors were physically inspected for mechanical damage as part of the response check process.

During the FSS, no instances were encountered where an instrument and/or detector failed a Pre or Post response check or were found to be physically damaged during the inspection.

7. SURVEY RESULTS After completion of the FSS measurements in the pipe, the sample plan was reviewed to confirm the completeness of the survey and the survey data was validated in accordance with procedure ZS-LT-300-001-004, Final Status Survey Data Assessment (Reference 13). Data processing includes converting measurement data into reporting units, validating instrument applicability and sensitivity, calculating relevant statistical quantities, and verification that all DQO have been met. In accordance with the procedure, a preliminary Data Assessment was prepared.

The primary gamma emitting ROC for the FSS of the Unit 2 Steam Tunnel Floor Drains FSS unit are Co-60, Cs-134 and Cs-137. Ni-63 and Sr-90 are also ROC for the Unit 2 Steam Tunnel Floor Drains. Ni-63 is inferred from the measured concentration of Co-60, while Sr-90 is inferred from the measured concentration of Cs-137. The ROC concentrations and OpSOF for each measurement taken in the Unit 2 Steam Tunnel Embedded Floor Drain Pipe are presented in Attachment 2. A statistical summary of the data is presented in Table 9.

[17]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Table 9 - Unit 2 Steam Tunnel Embedded Floor Drain Pipe - Measurement Results Individual Measurement Metrics Total Number of Systematic Measurements = 60 Number of Quality Control Measurements = 3 Number of Judgmental/Investigational Measurements = 0 Total Number of Measurements = 63 Mean Systematic Measurement OpSOF = 0.002 Max Individual Systematic Measurement OpSOF = 0.003 Number of Systematic Measurements with OpSOF >1 = 0 Statistical Quantities - Systematic Measurement Population MEAN MEDIAN MAX MIN ST DEV BcDCGL Avg Dose Avg SOF ROC per ROC (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) per ROC (mrem/yr)

Co-60 1.19E+04 1.16E+04 1.56E+04 9.87E+03 1.33E+03 1.41E+10 0.000 0.000 Cs-134 1.29E+02 1.26E+02 1.70E+02 1.07E+02 1.45E+01 3.19E+09 0.000 0.000 Cs-137 9.73E+05 9.47E+05 1.28E+06 8.08E+05 1.09E+05 4.22E+09 0.000 0.006 Ni-63 2.15E+06 2.09E+06 2.81E+06 1.78E+06 2.41E+05 4.36E+11 0.000 0.000 Sr-90 1.95E+03 1.89E+03 2.55E+03 1.62E+03 2.18E+02 1.55E+08 0.000 0.000 BASE CASE SOF (BcSOF) ASSIGNED TO SURVEY UNIT (SYSTEMATIC AVG.) = 0.000 DOSE ASSIGNED TO SURVEY UNIT (SYSTEMATIC AVG.) = 0.006

[18]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 All measurements were less than 50% of the OpDCGL, meeting the requirement for a Class 3 area. The data collected passed the Sign Test. The result of the Sign Test is provided in Attachment 3.

The activity in this pipe was also compared to the OpDCGLB for the building that contains it. According to Table 5-20 of the LTP, the Steam Tunnel drains are included with the Turbine Building. The results of this comparison showed that the OpSOFB for all of the measurements were less than one when compared to the OpDCGLB for the Turbine Building, with a maximum SOF of 0.770. Consequently, grouting of the Unit 2 Steam Tunnel Embedded Floor Drain Pipe was not required.

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. 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 readings and the original readings. Refer to Attachment 4 for quality control analysis results.
9. INVESTIGATIONS AND RESULTS As all measurements in the accessible pipe interior surface area was below an OpSOF of 0.5, no investigations were required or performed.
10. REMEDIATION AND RESULTS No remediation was performed in this piping survey unit.
11. CHANGES FROM THE SURVEY PLAN Only 120 feet of the piping was accessible for survey, therefore readings were taken at 2-foot intervals in the pipe run to obtain enough measurements to meet the 10% coverage requirement for a Class 3 survey unit.

The survey instructions called for a 44-157 detector to be used for the survey. Due to the size limitation for a 4-inch pipe, the smaller 44-159 detector was used instead.

12. DATA QUALITY ASSESSMENT (DQA)

In accordance with procedure ZS-LT-300-001-004, the DQOs, sample design, and data were reviewed for completeness, accuracy, and consistency. Documentation was complete and legible. The FSS unit was properly classified as Class 3. All measurement results were individually reviewed and validated. The number of measurements was sufficient to meet the requirement of 10% areal coverage of accessible surfaces. The

[19]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 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 meet the acceptance criteria as specified in the QAPP.

The data for Gross Gamma Activity 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.
14. CONCLUSION Sixty (60) static measurements were taken in the Unit 2 Steam Tunnel Embedded Floor Drain Pipe, taken at 2-foot intervals. The accessible length of pipe was 120 feet, therefore the areal coverage requirement of 10% for a Class 3 survey unit was met.

All of the measurements were below an OpSOF of 0.5. The average OpSOF for the survey unit was 0.002. The requirements for a Class 3 survey unit have been met.

The Sign Test was passed, and the Null Hypothesis was rejected. A Retrospective Power Curve showed that adequate power was achieved.

The dose contribution from embedded pipe in survey unit 06210, Unit 2 Steam Tunnel Embedded Floor Drain Pipe, is 0.006 mrem/yr TEDE, based on the average concentration of the ROC in samples used for non-parametric statistical sampling.

Survey unit 06210, Unit 2 Steam Tunnel Embedded Floor Drain Pipe is acceptable for unrestricted release.

15. REFERENCES
1. ZionSolutions procedure ZS-LT-300-001-005, Final Status Survey Data Reporting
2. Zion Station Restoration Project License Termination Plan
3. ZionSolutions procedure ZS-LT-300-001-001, Final Status Survey Package Development
4. NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual
5. ZionSolutions procedure ZS-LT-300-001-002, Survey Unit Classification
6. Zion Station Historical Site Assessment

[20]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210

7. ZionSolutions TSD 14-016, Description of Embedded Piping, Penetrations, and Buried Pipe to Remain in Zion End State
8. ZionSolutions TSD 17-004, Operational Derived Concentration Guideline Levels for Final Status Survey
9. ZionSolutions TSD 14-019, Radionuclides of Concern for Soil and Basement Fill Model Source Terms
10. ZionSolutions procedure ZS-LT-01, Quality Assurance Project Plan (for Characterization and FSS)
11. ZionSolutions procedure ZS-LT-300-001-003, Isolation and Control for Final Status Survey
12. ZionSolutions procedure ZS-LT-300-001-006, Radiation Surveys of Pipe Interiors Using Sodium/Cesium Iodide Detectors
13. ZionSolutions procedure ZS-LT-300-001-004, Final Status Survey Data Assessment
16. ATTACHMENTS Attachment 1 - Figures Attachment 2 - Sample Data Attachment 3 - Sign Test Attachment 4 - QC Sample Assessment Attachment 5 - Graphical Presentations

[21]

ATTACHMENT 1 - FIGURES

[22]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210

[23]

ATTACHMENT 2 - SAMPLE DATA

[24]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Unit 2 Steam Tunnel Embedded Floor Drain Pipe - Measurement Data FEET GROSS Co-60 Cs-134 Cs-137 Ni-63 Sr-90 POSITION INTO GAMMA OpSOFEP OpSOFB PIPE (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2)

Position #0 120 1.13E+06 1.37E+04 1.49E+02 1.12E+06 2.47E+06 2.24E+03 0.002 0.676 Position #1 118 1.18E+06 1.42E+04 1.54E+02 1.16E+06 2.56E+06 2.32E+03 0.003 0.701 Position #2 116 1.16E+06 1.40E+04 1.52E+02 1.15E+06 2.52E+06 2.29E+03 0.003 0.691 Position #3 114 1.08E+06 1.30E+04 1.41E+02 1.07E+06 2.35E+06 2.13E+03 0.002 0.642 Position #4 112 1.03E+06 1.24E+04 1.34E+02 1.01E+06 2.23E+06 2.03E+03 0.002 0.611 Position #5 110 9.66E+05 1.17E+04 1.27E+02 9.54E+05 2.10E+06 1.91E+03 0.002 0.575 Position #6 108 9.38E+05 1.13E+04 1.23E+02 9.26E+05 2.04E+06 1.85E+03 0.002 0.559 Position #7 106 9.01E+05 1.09E+04 1.18E+02 8.90E+05 1.96E+06 1.78E+03 0.002 0.537 Position #8 104 9.43E+05 1.14E+04 1.24E+02 9.31E+05 2.05E+06 1.86E+03 0.002 0.562 Position #9 102 1.00E+06 1.21E+04 1.31E+02 9.90E+05 2.18E+06 1.98E+03 0.002 0.597 Position #10 100 9.11E+05 1.10E+04 1.19E+02 9.00E+05 1.98E+06 1.80E+03 0.002 0.543 Position #11 98 9.22E+05 1.11E+04 1.21E+02 9.10E+05 2.01E+06 1.82E+03 0.002 0.549 Position #12 96 9.32E+05 1.12E+04 1.22E+02 9.21E+05 2.03E+06 1.84E+03 0.002 0.555 Position #13 94 9.82E+05 1.18E+04 1.29E+02 9.70E+05 2.14E+06 1.94E+03 0.002 0.585 Position #14 92 1.02E+06 1.23E+04 1.34E+02 1.01E+06 2.22E+06 2.02E+03 0.002 0.608 Position #15 90 8.85E+05 1.07E+04 1.16E+02 8.74E+05 1.93E+06 1.75E+03 0.002 0.527 Position #16 88 9.23E+05 1.11E+04 1.21E+02 9.12E+05 2.01E+06 1.82E+03 0.002 0.550 Position #17 86 9.20E+05 1.11E+04 1.21E+02 9.09E+05 2.00E+06 1.82E+03 0.002 0.548 Position #18 84 9.13E+05 1.10E+04 1.20E+02 9.02E+05 1.99E+06 1.80E+03 0.002 0.544 Position #19 82 8.94E+05 1.08E+04 1.17E+02 8.83E+05 1.95E+06 1.77E+03 0.002 0.532 Position #20 80 9.41E+05 1.14E+04 1.23E+02 9.30E+05 2.05E+06 1.86E+03 0.002 0.561 Position #21 78 9.59E+05 1.16E+04 1.26E+02 9.47E+05 2.09E+06 1.89E+03 0.002 0.571 Position #22 76 9.71E+05 1.17E+04 1.27E+02 9.59E+05 2.11E+06 1.92E+03 0.002 0.578 Position #23 74 9.99E+05 1.21E+04 1.31E+02 9.87E+05 2.18E+06 1.97E+03 0.002 0.595 Position #24 72 9.59E+05 1.16E+04 1.26E+02 9.47E+05 2.09E+06 1.89E+03 0.002 0.571 Position #25 70 9.13E+05 1.10E+04 1.20E+02 9.02E+05 1.99E+06 1.80E+03 0.002 0.544

[25]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Unit 2 Steam Tunnel Embedded Floor Drain Pipe - Measurement Data (continued)

FEET GROSS Co-60 Cs-134 Cs-137 Ni-63 Sr-90 POSITION INTO GAMMA OpSOFEP OpSOFB 2 2 2 2 2 2 PIPE (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m )

Position #26 68 1.03E+06 1.25E+04 1.36E+02 1.02E+06 2.25E+06 2.04E+03 0.002 0.616 Position #27 66 1.04E+06 1.25E+04 1.36E+02 1.02E+06 2.26E+06 2.05E+03 0.002 0.617 Position #28 64 1.22E+06 1.47E+04 1.60E+02 1.20E+06 2.65E+06 2.40E+03 0.003 0.725 Position #29 62 1.13E+06 1.36E+04 1.48E+02 1.12E+06 2.46E+06 2.23E+03 0.002 0.673 Position #30 60 1.15E+06 1.39E+04 1.51E+02 1.13E+06 2.50E+06 2.27E+03 0.003 0.684 Position #31 58 1.19E+06 1.44E+04 1.57E+02 1.18E+06 2.60E+06 2.36E+03 0.003 0.712 Position #32 56 1.29E+06 1.56E+04 1.70E+02 1.28E+06 2.81E+06 2.55E+03 0.003 0.770 Position #33 54 1.20E+06 1.44E+04 1.57E+02 1.18E+06 2.60E+06 2.36E+03 0.003 0.713 Position #34 52 1.07E+06 1.29E+04 1.40E+02 1.05E+06 2.32E+06 2.11E+03 0.002 0.636 Position #35 50 1.15E+06 1.39E+04 1.51E+02 1.13E+06 2.50E+06 2.27E+03 0.003 0.684 Position #36 48 1.02E+06 1.23E+04 1.33E+02 1.00E+06 2.21E+06 2.01E+03 0.002 0.606 Position #37 46 1.13E+06 1.37E+04 1.49E+02 1.12E+06 2.47E+06 2.24E+03 0.002 0.676 Position #38 44 9.27E+05 1.12E+04 1.22E+02 9.16E+05 2.02E+06 1.83E+03 0.002 0.552 Position #39 42 9.13E+05 1.10E+04 1.20E+02 9.02E+05 1.99E+06 1.80E+03 0.002 0.544 Position #40 40 9.32E+05 1.12E+04 1.22E+02 9.21E+05 2.03E+06 1.84E+03 0.002 0.555 Position #41 38 1.03E+06 1.25E+04 1.35E+02 1.02E+06 2.25E+06 2.04E+03 0.002 0.615 Position #42 36 1.04E+06 1.26E+04 1.37E+02 1.03E+06 2.27E+06 2.06E+03 0.002 0.622 Position #43 34 1.03E+06 1.24E+04 1.35E+02 1.01E+06 2.24E+06 2.03E+03 0.002 0.612 Position #44 32 1.00E+06 1.21E+04 1.31E+02 9.89E+05 2.18E+06 1.98E+03 0.002 0.596 Position #45 30 9.97E+05 1.20E+04 1.31E+02 9.85E+05 2.17E+06 1.97E+03 0.002 0.594 Position #46 28 8.71E+05 1.05E+04 1.14E+02 8.60E+05 1.90E+06 1.72E+03 0.002 0.519 Position #47 26 8.46E+05 1.02E+04 1.11E+02 8.36E+05 1.84E+06 1.67E+03 0.002 0.504 Position #48 24 8.78E+05 1.06E+04 1.15E+02 8.67E+05 1.91E+06 1.73E+03 0.002 0.523 Position #49 22 8.92E+05 1.08E+04 1.17E+02 8.81E+05 1.94E+06 1.76E+03 0.002 0.531 Position #50 20 9.41E+05 1.14E+04 1.23E+02 9.30E+05 2.05E+06 1.86E+03 0.002 0.561

[26]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Unit 2 Steam Tunnel Embedded Floor Drain Pipe - Measurement Data (continued)

FEET GROSS Co-60 Cs-134 Cs-137 Ni-63 Sr-90 POSITION INTO GAMMA OpSOFEP OpSOFB 2 2 2 2 2 2 PIPE (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m )

Position #51 18 9.64E+05 1.16E+04 1.26E+02 9.52E+05 2.10E+06 1.90E+03 0.002 0.574 Position #52 16 9.16E+05 1.11E+04 1.20E+02 9.05E+05 2.00E+06 1.81E+03 0.002 0.546 Position #53 14 8.18E+05 9.87E+03 1.07E+02 8.08E+05 1.78E+06 1.62E+03 0.002 0.487 Position #54 12 8.55E+05 1.03E+04 1.12E+02 8.44E+05 1.86E+06 1.69E+03 0.002 0.509 Position #55 10 8.34E+05 1.01E+04 1.09E+02 8.24E+05 1.82E+06 1.65E+03 0.002 0.497 Position #56 8 8.94E+05 1.08E+04 1.17E+02 8.83E+05 1.95E+06 1.77E+03 0.002 0.532 Position #57 6 8.46E+05 1.02E+04 1.11E+02 8.36E+05 1.84E+06 1.67E+03 0.002 0.504 Position #58 4 8.69E+05 1.05E+04 1.14E+02 8.58E+05 1.89E+06 1.72E+03 0.002 0.518 Position #59 2 8.41E+05 1.01E+04 1.10E+02 8.31E+05 1.83E+06 1.66E+03 0.002 0.501

[27]

ATTACHMENT 3 - SIGN TEST

[28]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Sign Test - Unit 2 Steam Tunnel Embedded Floor Drain Pipe Survey Area 06000 Survey Area Unit 2 Steam Tunnel Survey Unit 06210 Survey Unit Floor Drain Pipe (embedded)

Classification 3 Type I Error 0.05 Number of Measurements 60 SOF SOF

  1. 1-Ws Sign # 1-Ws Sign (Ws) (Ws) 1 0.002 1.00 -1 31 0.003 1.00 +1 2 0.003 1.00 +1 32 0.003 1.00 +1 3 0.003 1.00 +1 33 0.003 1.00 +1 4 0.002 1.00 +1 34 0.003 1.00 +1 5 0.002 1.00 +1 35 0.002 1.00 +1 6 0.002 1.00 +1 36 0.003 1.00 +1 7 0.002 1.00 +1 37 0.002 1.00 +1 8 0.002 1.00 +1 38 0.002 1.00 +1 9 0.002 1.00 +1 39 0.002 1.00 +1 10 0.002 1.00 +1 40 0.002 1.00 +1 11 0.002 1.00 +1 41 0.002 1.00 +1 12 0.002 1.00 +1 42 0.002 1.00 +1 13 0.002 1.00 +1 43 0.002 1.00 +1 14 0.002 1.00 +1 44 0.002 1.00 +1 15 0.002 1.00 +1 45 0.002 1.00 +1 16 0.002 1.00 +1 46 0.002 1.00 +1 17 0.002 1.00 +1 47 0.002 1.00 +1 18 0.002 1.00 +1 48 0.002 1.00 +1 19 0.002 1.00 +1 49 0.002 1.00 +1 20 0.002 1.00 +1 50 0.002 1.00 +1 21 0.002 1.00 +1 51 0.002 1.00 +1 22 0.002 1.00 +1 52 0.002 1.00 +1 23 0.002 1.00 +1 53 0.002 1.00 +1 24 0.002 1.00 +1 54 0.002 1.00 +1 25 0.002 1.00 +1 55 0.002 1.00 +1 26 0.002 1.00 +1 56 0.002 1.00 +1 27 0.002 1.00 +1 57 0.002 1.00 +1 28 0.002 1.00 +1 58 0.002 1.00 +1 29 0.003 1.00 +1 59 0.002 1.00 +1 30 0.002 1.00 +1 60 0.002 1.00 +1 Number of positive differences (S+) 60 Critical Value 36 The Survey Unit MEETS the Acceptance Criteria

[29]

ATTACHMENT 4 - QC SAMPLE ASSESSMENT

[30]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Unit 2 Steam Tunnel Embedded Drain Pipe - QC Agreement Survey Unit # 06210 Survey Unit Name Unit 2 Steam Tunnel Embedded Floor Sample Plan # S3-06210A-F Drain Sample

Description:

Comparison of replicate measurements collected from four measurement locations accessed from cleanout M205.

STANDARD COMPARISON ID Activity Value +20% -20% ID Activity Value Acceptable (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (Y/N) 98' into pipe 9.22E+05 1.11E+06 7.37E+05 98' into pipe 8.69E+05 Y 70' into pipe 9.13E+05 1.10E+06 7.30E+05 70' into pipe 9.43E+05 Y 28' into pipe 8.71E+05 1.04E+06 6.97E+05 28' into pipe 8.44E+05 Y Comments/Corrective Actions: There was The acceptance criteria for replicate static acceptable agreement between the standard measurements and scan surveys are that the measurement and the replicate measurement. Based same conclusion is reached for each on the professional judgment of the Radiological measurement. This is defined as + 20% of Engineer, the same conclusion was reached for each the standard.

measurement. No further action is necessary.

[31]

ATTACHMENT 5 - GRAPHICAL PRESENTATIONS

[32]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 QUANTILE PLOT for Gross Gamma Activity Survey Unit: S3-06210 Survey Unit Name: Unit 2 Steam Tunnel Drains Embedded Pipe Mean: 9.85E+05 Quantile Plot For Gross Gamma Activity 1.40E+06 1.30E+06 Gross Activity (pCi/m2) 1.20E+06 1.10E+06 1.00E+06 9.00E+05 8.00E+05 7.00E+05 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Percentage

[33]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Histogram for Gross Gamma Activity Survey Unit: S3-06210 Survey Unit Name: Unit 2 Steam Tunnel Drains Embedded Pipe Mean: 9.85E+05 pCi/m2 Median: 9.59E+05 pCi/m2 ST DEV: 1.11E+05 pCi/m2 Skew: 8.05E-01 pCi/m2 Frequency Plot for Gross Gamma Activity 18 16 14 12 Frequency 10 8

6 4

2 0

8.77E+05 9.37E+05 9.96E+05 1.06E+06 1.11E+06 1.17E+06 1.23E+06 1.29E+06 Upper End Value (pCi/m2 Upper Observation Observation Value Frequency  %

8.77E+05 8 13%

9.37E+05 17 28%

9.96E+05 10 17%

1.06E+06 12 20%

1.11E+06 2 3%

1.17E+06 6 10%

1.23E+06 4 7%

1.29E+06 1 2%

TOTAL 60 100%

[34]

FSS RELEASE RECORD UNIT 2 STEAM TUNNEL FLOOR DRAIN PIPE SURVEY UNIT 06210 Retrospective Power Curve for Survey Unit 06210

[35]

Retrieved from "https://kanterella.com/w/index.php?title=ML19295G855&oldid=2161970"