ML20352A242

Response to Request for Additional Information Re Revised Final Status Survey Final Reports, S2-011-103 Release Record, Revision 1, Final, Circulating Water Intake Pipe

ML20352A242
Person / Time
Site:	La Crosse  File:Dairyland Power Cooperative icon.png
Issue date:	11/02/2020
From:	La CrosseSolutions
To:	Office of Nuclear Material Safety and Safeguards
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References
LC-2020-0023
Download: ML20352A242 (32)

Text

LA CROSSE BOILING WATER REACTOR FINAL STATUS SURVEY RELEASE RECORD CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 REVISION 1

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LACROSSE SOLUTIONS

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 1

PREPARED BY / DATE:

R. F. Yetter III, FSS Specialist REVIEWED BY / DATE:

M. D. Uz, FSS Specialist REVIEWED BY / DATE:

R. Yetter, Director, Radiological Site Closure REVIEWED BY / DATE:

S. Roberts, VP Radiological Programs APPROVED BY / DATE:

S. Zoller, FSS Manager

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LACROSSESOLUTIONS

/4&~

Robert F. Yetter III Oct 25 2020 1 :57 PM cosign

~~

Mitchell Uz Oct 27 2020 8:03 AM cosi n

~5.'ljdwt Robert F. Yetter Oct 27 2020 11 :09 AM cosign Sa,zale 1!!:~

Sarah Roberts Oct 27 2020 12:59 PM cosign

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Scott G. Zoller

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Oct 29 2020 9:40 AM cosign

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 2

TABLE OF CONTENTS 1.

EXECUTIVE

SUMMARY

............................................................................................................................5 2.

SURVEY UNIT DESCRIPTION...................................................................................................................5 3.

CLASSIFICATION BASIS...........................................................................................................................5 4.

DATA QUALITY OBJECTIVES..................................................................................................................6 5.

SURVEY DESIGN.........................................................................................................................................9 6.

SURVEY IMPLEMENTATION.................................................................................................................13 7.

SURVEY RESULTS....................................................................................................................................14 8.

QUALITY CONTROL................................................................................................................................15 9.

INVESTIGATIONS AND RESULTS..........................................................................................................16 10.

REMEDIATION AND RESULTS...............................................................................................................16 11.

CHANGES FROM THE FINAL STATUS SURVEY PLAN......................................................................16 12.

DATA QUALITY ASSESSMENT...............................................................................................................16 13.

ANOMALIES...............................................................................................................................................17 14.

CONCLUSION............................................................................................................................................17 15.

REFERENCES............................................................................................................................................17 16.

ATTACHMENTS........................................................................................................................................18 ATTACHMENT 1 - FIGURES AND MAPS.........................................................................................................19 ATTACHMENT 2 - MEASUREMENT DATA......................................................................................................21 ATTACHMENT 3 - SIGN TEST.........................................................................................................................24 ATTACHMENT 4 - QUALITY CONTROL ASSESSMENT...................................................................................26 ATTACHMENT 5 - GRAPHICAL PRESENTATIONS.........................................................................................28

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 3

LIST OF TABLES Table 4 Dose Significant Radionuclides and Mixture for Buried Pipe.............................................................7 Table 4 Base Case DCGLs for Buried Pipe Group...........................................................................................8 Table 4 Operational DCGLs for Buried Pipe Group.......................................................................................9 Table 5 Soil Surrogate Ratio............................................................................................................................9 Table 5 Investigation Levels...........................................................................................................................12 Table 5 Synopsis of Survey Design.................................................................................................................12 Table 7 Summary of Systematic and QC Measurements...............................................................................15 Table 7 Basic Statistical Properties of the Systematic Measurement Population..........................................15 Table 16 Survey Unit S2-011-103 Static Measurements Data Assessment....................................................22 Table 16 Survey Unit S2-011-103 Sign Test...................................................................................................25 Table 16 Survey Unit S2-011-103 QC Assessment.........................................................................................27 LIST OF FIGURES Figure 16 Survey Unit S2-011-103 Drawing...................................................................................................20 Figure 16 Quantile Plot for Gross Gamma Activity.......................................................................................29 Figure 16 Histogram for Gross Gamma Activity...........................................................................................30 Figure 16 Retrospective Power Curve for Survey Unit S2-011-103...............................................................31

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LACROSSESOLUTIONS

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 4

LIST OF ACRONYMS AND ABBREVIATIONS ALARA As Low As Reasonably Achievable CWD Circulating Water Discharge CWI Circulating Water Intake DQO Data Quality Objective DCGL Derived Concentration Guideline Level DCGLBP Buried Pipe Base Case Derived Concentration Guideline Level FSS Final Status Survey HSA Historical Site Assessment IC Insignificant Contributors ID Internal Diameter LACBWR La Crosse Boiling Water Reactor LTP License Termination Plan MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MCNP Monte Carlo Neutral Particle MDC Minimum Detectable Concentration NaI Sodium Iodide OpDCGLBP Buried Pipe Operational Derived Concentration Guideline Level QAPP Quality Assurance Project Plan QC Quality Control ROC Radionuclides of Concern SOF Sum of Fractions TEDE Total Effective Dose Equivalent TSD Technical Support Document UCL Upper Confidence Limit

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LACROSSESOLUTIONS

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 5

1.

EXECUTIVE

SUMMARY

This Final Status Survey (FSS) Release Record for survey unit S2-011-103, Circulating Water Intake (CWI) Pipe, has been generated in accordance with LaCrosseSolutions procedure LC-FS-PR-009, Final Status Survey Data Reporting (Reference 1) and satisfies the requirements of Section 5.11 of the La Crosse Boiling Water Reactor License Termination Plan (LACBWR LTP) (Reference 2).

An FSS sample plan for this survey unit was developed in accordance with LaCrosseSolutions procedures LC-FS-PR-002, Final Status Survey Package Development (Reference 3) and LC-FS-PR-018, Radiation Surveys of Pipe Interiors Using Sodium/Cesium Iodide Detectors (Reference 4), the LACBWR LTP, and with guidance from NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (Reference 5).

Survey unit S2-011-103 has a MARSSIM classification of 2. A survey plan was designed based upon use of the Sign Test as the nonparametric statistical test for compliance. Both the Type I ( ) and Type II ( ) decision error rates were set at 0.05. As a systematic measurement population, twenty-nine (29) static gamma measurements were acquired from the survey unit. The data assessment results for survey unit S2-011-103 indicate that the maximum Sum of Fractions (SOF), considering the concentration of all applicable Radionuclides of Concern (ROC) either by direct measurement or by inference, is equal to 0.1309 when applying the respective Operational Derived Concentration Guideline Levels (OpDCGLBP) for buried pipe. The mean SOF when applying the respective Base Case DCGLs (DCGLBP) is 0.0240. This SOF equates to a dose for the survey unit of 0.6005 mrem/yr.

2.

SURVEY UNIT DESCRIPTION S2-011-103 is an impacted Class 2 buried pipe survey unit. The survey unit consists of the interior surface of the CWI Pipe, which is two (2) 42 internal diameter (ID) steel pipes that merge into a 60 ID steel pipe that runs from the LACBWR Crib House to the Turbine Building. The total length of pipe is approximately 46.5 feet (14.17 m). The total interior surface area of the CWI Pipe is 56.91 m2 (569,134 cm2). Refer to Attachment 1 of this report for a figure depicting survey unit S2-011-103.

3.

CLASSIFICATION BASIS Based on the La Crosse Boiling Water Reactor Historical Site Assessment (HSA)

(Reference 6), the CWI Pipe was identified as a Class 2 system.

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LACROSSESOLUTIONS a

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 6

Based upon review of the historical information and completion of a final Survey Unit Classification Worksheet from LC-FS-PR-006, Survey Unit Classification (Reference 7),

the correct final classification of survey unit S2-011-103 was determined to be Class 2.

4.

DATA QUALITY OBJECTIVES FSS planning and design relies on a properly executed 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 LACBWR 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 unit S2-011-103 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).

EnergySolutions Technical Support Document (TSD) RS-TD-313196-001, Radionuclides of Concern during LACBWR Decommissioning (Reference 8) established the basis for an initial suite of potential ROC for decommissioning. Insignificant contributors (IC) were determined consistent with the guidance contained in Section 3.3 of NUREG-1757, Volume 2, Revision 1, Consolidated Decommissioning Guidance - Characterization, Survey, and Determination of Radiological Criteria, Final Report (Reference 9). In all soil and concrete scenarios, Cs-137, Co-60, Sr-90, Eu-152 and Eu-154 contribute nearly 100% of the total dose. The remaining radionuclides were designated as IC and are eliminated from further detailed evaluation. Therefore, the final ROCs for LACBWR soil, basement concrete, and buried piping are Cs-137, Co-60, Sr-90, Eu-152 and Eu-154.

LTP, Section 6.14.1 discusses the process used to derive the ROC for the decommissioning of LACBWR, including the elimination of IC from the initial suite. Table 4-1 presents the

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LACROSSESOLUTIONS

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 7

ROC for the decommissioning of buried pipe at LACBWR and the normalized mixture fractions based on the radionuclide mixture.

Table 4 Dose Significant Radionuclides and Mixture for Buried Pipe Radionuclide Fraction of Total Activity (normalized)(1)

Co-60 0.064 Sr-90 0.098 Cs-137 0.829 Eu-152 0.005 Eu-154 0.003 (1) Based on maximum percent of total activity from Table 22 of RS-TD-313196-001, normalized to one for the dose significant radionuclides.

The LTP, Section 5.2, states that each radionuclide-specific Base Case DCGL 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. To ensure that the summation of dose from each source term is 25 mrem/yr or less after all FSS is completed, the Base Case DCGLs 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 Base Case DCGLs 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 Operational DCGL is then used as the DCGL for the FSS design of the survey unit (i.e., calculation of surrogate DCGLs and investigation levels).

Details of the Operational DCGLs derived for each dose component and the basis for the applied a priori dose fractions are provided in LC-FS-TSD-002, Operational Derived Concentration Guideline Levels for Final Status Survey (Reference 10).

The dose contribution from each ROC is accounted for using the SOF to ensure that the total dose from all ROC does not exceed the dose criterion. A Base Case DCGL that is established for the average residual radioactivity in a survey unit is equivalent to a DCGLW.

The DCGLW can be multiplied by Area Factors to obtain a Base Case DCGL that represents the same dose to an individual for residual radioactivity over a smaller area within a survey unit.

At LACBWR, compliance is demonstrated through the summation of dose from five (5) distinct source terms for the end state (basements, soils, buried pipe, above-ground structures, and groundwater). When applied to buried pipe, the DCGLs are expressed in units of activity per surface area (dpm/100 cm2).

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LACROSSESOLUTIONS

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 8

Buried piping is defined as below ground pipe located outside of structures and basements.

The dose assessment methods and resulting DCGLs for buried piping are described in detail in LTP, Section 6.20. The buried piping was separated into two categories. The first category included the summation and grouping of all impacted buried pipe other than the Circulating Water Discharge (CWD) Pipe and is designated as the Buried Pipe Group.

The second category consisted of the CWD Pipe only. The separation of the CWD pipe was necessary because the geometry was significantly different than the other pipes, and the pipes are located in distinctly different parts of the site.

EnergySolutions TSD RS-TD-313196-004, LACBWR Soil DCGL, Basement Concrete DCGL, and Buried Pipe DCGL (Reference 11) and LTP, Section 6.20, provide the exposure scenarios and modeling parameters that were used to calculate the site-specific buried pipe DCGLs. The final DCGLs used during FSS account for the fact that the dose from the In Situ and Excavation scenarios must be summed in the conceptual model for buried pipe dose assessment (i.e., the In Situ and Excavation scenarios occur in parallel). The summed Buried Pipe Base Case DCGLs are reproduced in Table 4-2 below. The IC dose percentages for each of the buried pipe scenarios were used to adjust each buried pipe Base Case DCGL to account for the dose from the eliminated IC radionuclides. The Operational DCGLs for the CWI Pipe are provided in Table 4-3.

Table 4 Base Case DCGLs for Buried Pipe Group Radionuclide DCGLBP (dpm/100 cm2)

Co-60 7.50E+04 Sr-90 5.16E+05 Cs-137 3.18E+05 Eu-152 1.64E+05 Eu-154 1.52E+05

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LACROSSESOLUTIONS

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 9

Table 4 Operational DCGLs for Buried Pipe Group Radionuclide OpDCGLBP (dpm/100 cm2)

Co-60 1.57E+04 Sr-90 1.08E+05 Cs-137 6.68E+04 Eu-152 3.44E+04 Eu-154 3.20E+04 Instrument DQOs included a verification of the ability of the survey instrument to detect the radiation(s) of interest relative to the Operational DCGL. 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.

In accordance with the LTP, the minimum acceptable MDC for measurements obtained using field instruments was 50% of the applicable Operational DCGL.

5.

SURVEY DESIGN The level of effort associated with planning a survey is based on the complexity of the survey unit and nature of the hazards. Guidance for preparing FSS plans is provided in procedure LC-FS-PR-002, Final Status Survey Package Development.

The DQO process validated that Co-60, Sr-90, Cs-137, Eu-152, and Eu-154 would be the ROC in survey unit S2-011-103 as presented in LTP Section 5.1. During the data analysis of the FSS results, concentrations for the HTD ROC Sr-90 are inferred using a surrogate approach. Cs-137 is the principle surrogate radionuclide for Sr-90. During characterization, both Sr-90 and Cs-137 was positively detected in all thirty (30) concrete core samples assessed in the Reactor Building, Tunnel, and Waste Treatment Building. The 95% Upper Confidence Limit (UCL) of the Cs-137 fractions was chosen to represent the overall nuclide mix for soils/buried pipe, the Reactor Building, and the Waste Gas Tank Vault. The surrogate ratio for soil/buried pipe is given in Table 5-1.

Table 5 Soil Surrogate Ratio Radionuclides Ratio Sr-90/Cs-137 0.502 The equation for calculating a surrogate DCGL is as follows:

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LACROSSESOLUTIONS

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 10 Equation 1

=

1 1

+

+

+

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 Operational DCGLs presented in Table 4-3 and the ratio from Table 5-1, the following surrogate calculation was performed:

Equation 2

(

) =

1 1

6.68

+ 04(

) +

0.502 1.08

+ 05(

)

= 5.10

+ 04

/100 The surrogate Operational DCGL for Cs-137 is then used in the calculation of the gross gamma Operational DCGL, as calculated in Equation 3.

Equation 3

(

)

=

1 0.071 1.57

+ 04(

) +

0.919 5.10

+ 04

+

0.006 3.44

+ 04(

) +

0.003 3.20

+ 04(

)

= 4.37

+ 04

/100 The action level for survey unit S2-011-103 was equivalent to the calculated gross gamma Operational DCGL of 4.37E+04 dpm/100 cm2.

For the survey of interior pipe surfaces, areal coverage is achieved by the area of detection for each static measurement collected. Scanning, in the traditional context, is not applicable to the survey of pipe internal surfaces. For the survey of the CWI Pipe, the detector was erroneously calibrated for a specific geometry of a 3,050 cm2 (1 ft x 1 m) area of contamination on the bottom of the pipe, resulting in inaccurate detector efficiencies and inaccurate calculations for activity per area. TSD LC-FS-TSD-005, MCNP Modeling of Water Discharge Pipes for the LaCrosse Boiling Water Reactor (Reference 12) was written

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LACROSSESOLUTIONS SurrogatevccL SurrogatevccL cs-137

[ (-E-cs--137) (

E Sr-90 ) ]

E dpm cm2 SurrogatevcGL gamma

[(

E Co-60 )

(

E Cs-137)

(

E Eu-152 )

(

E Eu-154 ) ]

E dpm cm2

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 11 to address the discrepancy in efficiency and area of detection. The TSD details the Monte Carlo Neutral Particle (MCNP) radiation transport code that modeled the response of a NaI detector to a calibration source for several different pipe sizes. The MCNP models resulted in efficiency correction factors. The calculated efficiency from original source calibration can be multiplied by the correction factors to obtain an efficiency that more realistically portrays the specific contamination geometry of the pipe. For a 60 ID pipe, each measurement has a true Field-of-View (FOV) of 14,590 cm2. Although approximately half the pipe is the smaller 42 ID, the same detector calibrated for a 60 ID pipe was used. This provided for a fluid and efficient survey and ensured that measurements for the 42 ID portion of the CWI were conservative.

The CWI Pipe contains 46.5 linear feet of 42 ID and 60 ID steel piping, which equates to a surface area of 56.91 m2 (569,134 cm2). The LTP states that a Class 2 FSS unit shall have an areal coverage of 10% to 100%. For survey unit S2-011-103, 50% survey coverage was selected. Therefore, a total of at least twenty-four (24) distinct measurements over the entire accessible pathway of the piping system were required. During survey design, five (5) systematic static measurements were added, for a total of twenty-nine (29) static measurements that make up the systematic measurement population.

Each static measurement represents the gamma activity in gross counts per minute (cpm) for each specific measurement location. Background is subtracted, then the value is converted to dpm using an efficiency factor based on the calibration source and the efficiency correction factors detailed in TSD LC-FS-TSD-005, MCNP Modeling of Water Discharge Pipes for the LaCrosse Boiling Water Reactor. The total activity in dpm is then adjusted for the assumed effective surface area commensurate with the pipe diameter, resulting in units of dpm/100 cm2. The total gamma surface activity for each measurement was converted to an activity concentration for each gamma-emitting ROC, based on the normalized gamma mixture from Table 4-1. Concentrations for the HTD ROC Sr-90 were inferred using the surrogate approach in accordance with LTP Chapter 5.

The implementation of quality control measures as referenced by LTP, Section 5.9 and LaCrosseSolutions LC-QA-PN-001, Final Status Survey Quality Assurance Project Plan (QAPP) (Reference 13) includes the collection of replicate static measurements on 5% of the systematic measurements collected in the survey unit, with the locations selected at random. Two (2) replicate static measurements were selected for Quality Control (QC) analysis for the FSS of this survey unit.

For this Class 2 buried pipe survey unit, the Investigation Levels for measurement results are those levels specified in LTP Chapter 5, Table 5-16, and are reproduced below in Table 5-2.

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 12 Table 5 Investigation Levels Classification Scan Investigation Levels Direct Investigation Levels Class 2

>Operational DCGL or >MDCscan if MDCscan is greater than Operational DCGL

>Operational DCGL Table 5-3 provides a synopsis of the survey design for survey unit S2-011-103.

Table 5 Synopsis of Survey Design Feature Design Criteria Basis Survey Unit Surface Area 56.91 m2 (569,314 cm2) 46.5 of 60 and 42 diameter steel pipe Number of Systematic Measurements (N) 29 50% coverage Operational DCGLs (dpm/100 cm2)

Co-60: 1.57E+04 Sr-90: 1.08E+05 Cs-137: 6.68E+04 Eu-152: 3.44E+04 Eu-154: 3.20E+04 Operational DCGLs for buried pipe, LTP, Table 5-8, Release Record, Table 4-3 Action Level 4.37E+04 dpm/100 cm2 Gross Gamma Operational DCGL, Equation 3 Investigation Level

>Operational DCGL LTP, Table 5-16 Scan Areal Coverage N/A LTP, Section 5.7.1.8 QC 2 replicate measurements LTP, Section 5.9 Number of Judgmental Measurements 1

Per Sample Plan Non-parametric Statistical Test Sign Test LTP, Section 5.6.4.2

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 13 6.

SURVEY IMPLEMENTATION FSS field activities were conducted under the FSS sample plan, which included DQOs, survey design, detailed FSS instructions, job safety analysis, and related procedures for reference. The survey unit was inspected and controlled in accordance with LC-FS-PR-010, Isolation and Control for Final Status Survey (Reference 14). A Field Log was used to document field activities and other information pertaining to the performance of the FSS.

FSS field activities commenced on March 28, 2018.

FSS field activities were projected to take four (4) working days to complete. Daily briefings were conducted to discuss the expectations for job performance and to review safety aspects of the job. The survey-required field activities were performed during normal working hours and concluded on March 28, 2018.

Background measurements were acquired in the North Yard area of the site. These readings were found to be inconsistent with the activity measured in the pipe; nearly all measurements were negative after subtracting background. It was determined that the backgrounds originally collected for the CWI pipe were not representative of true background levels. Because the CWI pipe was no longer accessible after survey implementation, a background study was performed by collecting measurements on a buried piece of 60 ID steel pipe. The background study measurements were determined to still be too high, due to the length of the pipe being too short. It was decided, then, that background would not be subtracted from any measurement in the CWI pipe. This provided a reasonable and conservative solution that did not require the re-excavation of soil above the pipe to access it.

Daily, prior to and following use, each detector was subjected to an Operational Response Check in accordance with procedure LC-FS-PR-018, Radiation Surveys of Pipe Interiors Using Sodium/Cesium Iodide Detectors. The Daily Operational Response Check compared the background response and the response to check source ranges established for normal background and detector source response to ensure that the detector was working properly.

The thirty (30) systematic 1-minute static measurements were collected using a Ludlum Model 2350-1 paired with a Model 44-10 NaI detector operated in the rate-meter mode and using audio response. The detector was fitted into a wheeled rig, which maintained a fixed detector geometry, an area of detection of 14,590 cm2. The static MDC was sufficient to detect residual radioactivity at the action level (adjusted gross gamma Operational DCGL of 4.37E+04 dpm/100 cm2). Complete measurement results are provided in Attachment 2.

One (1) judgmental static measurement was collected during implementation of FSS, in accordance with the sample plan.

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 14 The implementation of survey specific QC measures included the collection of two (2) replicate static measurements for QC analysis.

7.

SURVEY RESULTS 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 application of the unity rule serves to normalize the data to allow for an accurate comparison of the various data measurements to the release criteria. When the unity rule is applied, the DCGLW (used for the nonparametric statistical test) becomes one (1). The DCGLBP are directly analogous to the DCGLW as defined in MARSSIM. The use and application of the unity rule was performed in accordance with section 4.3.3 of MARSSIM.

As described in LTP, Section 5.10.3.2, the Sign Test was used to evaluate the measured residual radioactivity against the dose criterion. The SOF for each measurement was used as the sum value for the Sign Test. The Sign Test then demonstrated that the mean activity for each ROC was less than the OpDCGLBP at a Type I decision error of 0.05. The results of the Sign Test are presented in Attachment 3.

For buried pipe, areas of elevated activity were defined as any area identified by measurement (systematic or judgmental) that exceeded the OpDCGLBP but was less than the DCGLBP. The SOF (based on the OpDCGLB) for a systematic or judgmental measurement can exceed one (1) without remediation as long as the survey unit passes the Sign Test, and the mean SOF (based on the OpDCGLBP) for the survey unit does not exceed one (1). Once the survey data set passes the Sign Test (using Operational DCGLs), then the mean radionuclide activity for each ROC from systematic measurements along with any identified elevated areas from systematic and judgmental samples can be used with the Base Case DCGLs to perform a mean SOFBP calculation. The dose from residual radioactivity assigned to the FSS unit is the mean SOFBP multiplied by 25 mrem/yr.

The systematic measurement population consisted of twenty-nine (29) static measurements that were acquired using the Ludlum Model 2350-1 paired to a Model 44-10 detector. In total, thirty-two (32) static measurements were collected, including the systematic, 1

2 2

1 1

DCGL C

DCGL C

DCGL C

n n

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LACROSSESOLUTIONS

--+--+

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 15 judgmental, and QC measurements. A breakdown of the total static measurements and SOF for systematic measurements compared to the OpDCGLBP is provided in Table 7-1. A summary of the results of the systematic measurements taken for non-parametric statistical testing when compared to the DCGLBP is provided in Table 7-2. The complete results of the data assessment for survey unit S2-011-103 are provided in Attachment 2.

Table 7 Summary of Systematic and QC Measurements Total Number of Systematic Measurements 29 Number of Quality Control Measurements 2

Number of Judgmental Measurements 1

Total Number of Measurements 32 Mean Systematic Measurement SOF (1) 0.1142 Max Individual Systematic Measurement SOF (1) 0.1309 Number of Systematic Measurements with SOF > 1 (1) 0 Number of Judgmental Measurements with SOF > 1 (1) 0 (1) Based on the OpDCGLBP Table 7 Basic Statistical Properties of the Systematic Measurement Population ROC Mean Median Max.

Min.

St. Dev.

(dpm/100 cm2)

BcDCGL Avg. SOF per ROC Avg. Dose per ROC (dpm/100 cm2)

(dpm/100 cm2)

(dpm/100 cm2)

(dpm/100 cm2)

(dpm/100 cm2)

Co-60 3.58E+02 3.60E+02 4.09E+02 2.44E+02 2.87E+01 7.50E+04 0.0048 0.1192 Cs-137 4.60E+03 4.64E+03 5.26E+03 3.13E+03 3.70E+02 3.18E+05 0.0145 0.3620 Eu-152 3.05E+01 3.07E+01 3.49E+01 2.08E+01 2.45E+00 1.64E+05 0.0002 0.0046 Eu-154 1.56E+01 1.57E+01 1.78E+01 1.06E+01 1.25E+00 1.52E+05 0.0001 0.0026 Sr-90 2.31E+03 2.33E+03 2.64E+03 1.57E+03 1.86E+02 5.16E+05 0.0045 0.1120 SUM 0.0240 0.6005 The mean SOF for the CWI Pipe, based on the mean concentration for each ROC as measured by the systematic measurement population when compared against the DCGLBP, is 0.0240. This SOF equates to a dose of 0.6005 mrem/yr.

8.

QUALITY CONTROL The implementation of survey specific QC measures included the collection of two (2) replicate static measurements for QC analysis. The acceptance criteria for replicate static measurements is that the same conclusion is reached for each measurement. This is defined as the replicate measurement being within 20% of the standard measurement. In cases where

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 16 the replicate measurement is not within 20% of the standard measurement, but both measurements are below the Operational DCGL, there is an acceptable agreement. Both QC replicate measurement fell within the 20% criteria, and there is an acceptable agreement between standard and replicate results. Refer to Attachment 4 for QC analysis results.

9.

INVESTIGATIONS AND RESULTS No investigations were performed during the performance or analyses of the survey.

10.

REMEDIATION AND RESULTS No radiological remedial action as described by MARSSIM Section 5.4 was performed in this survey unit. Chapter 4 of the LTP determined that remediation beyond that required to meet the release criteria is unnecessary and that the remaining residual radioactivity in buried pipe was ALARA.

11.

CHANGES FROM THE FINAL STATUS SURVEY PLAN TSD LC-FS-TSD-005, MCNP Modeling of Water Discharge Pipes for the LaCrosse Boiling Water Reactor, was developed in response to the inaccurate efficiency calibration geometry originally assumed in the sample plan and during survey implementation. Additionally, as described in section 6 of this release record, background was not subtracted from the measurements.

12.

DATA QUALITY ASSESSMENT The DQO survey design and data were reviewed in accordance with LC-FS-PR-008, Final Status Survey Data Assessment (Reference 15) for completeness and consistency.

Documentation was complete and legible. Surveys were consistent with the DQOs and were sufficient to ensure that the survey unit was properly designated as Class 2. The survey design had adequate power as indicated by the Retrospective Power Curve (see Attachment 5).

All measurements were less than a SOF of one (1) when compared to the OpDCGLBP.

The Sign Test 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 unit passes 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 that exceeded two standard deviations. The mean and median values for each ROC were well below the respective

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 17 Operational DCGLs. Also, the retrospective power curve shows that a sufficient number of measurements were collected to achieve the desired power. Therefore, the survey unit meets the unrestricted release criteria with adequate power as required by the DQOs.

13.

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

14.

CONCLUSION Survey unit S2-011-103 has met the DQOs of the FSS plan. The ALARA criteria as specified in Chapter 4 of the LTP were achieved.

The sample data passed the Sign Test. The null hypothesis was rejected. The Retrospective Power Curve showed that adequate power was achieved. The survey unit is properly classified as Class 2. Therefore, in accordance with LTP Section 5.11, the survey unit meets the release criteria.

The dose contribution from survey unit S2-011-103 is 0.6005 mrem/yr TEDE, based on the average concentration of the ROC in measurements used for non-parametric statistical testing (mean SOF).

Survey unit S2-011-103 is acceptable for unrestricted release.

15.

REFERENCES

1. LC-FS-PR-009, Final Status Survey Data Reporting

2. La Crosse Boiling Water Reactor License Termination Plan

3. LC-FS-PR-002, Final Status Survey Package Development

4. LC-FS-PR-018, Radiation Surveys of Pipe Interiors Using Sodium/Cesium Iodide Detectors

5. NUREG-1575, Revision 1, Multi-Agency Radiation Survey and Site Investigation Manual

6. La Crosse Boiling Water Reactor Historical Site Assessment

7. LC-FS-PR-006, Survey Unit Classification

8. RS-TD-313196-001, Radionuclides of Concern during LACBWR Decommissioning

9. NUREG-1757, Volume 2, Revision 1, Consolidated Decommissioning Guidance -

Characterization, Survey, and Determination of Radiological Criteria, Final Report

10. LC-FS-TSD-002, Operational Derived Concentration Guideline Levels for Final Status Survey DCGL

11. RS-TD-313196-004, LACBWR Soil DCGL, Basement Concrete DCGL, and Buried Pipe

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 18

12. LC-FS-TSD-005, MCNP Modeling of Water Discharge Pipes for the LaCrosse Boiling Water Reactor

13. LC-QA-PN-001, Final Status Survey Quality Assurance Project Plan

14. LC-FS-PR-010, Isolation and Control for Final Status Survey

15. LC-FS-PR-008, Final Status Survey Data Assessment 16.

ATTACHMENTS - Figures and Maps - Measurement Data - Sign Test - Quality Control Assessment - Graphical Presentations

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 19 ATTACHMENT 1 FIGURES AND MAPS

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 20 Figure 16 Survey Unit S2-011-103 Drawing

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, I

. l

. I I

• i I **

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 21 ATTACHMENT 2 MEASUREMENT DATA

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SUR VEY UNIT S2-011-103

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LACROSSESOLUTIONS Table 16-1-Survey Unit S2-011-103 Static Measurements Data Assessment Measurement Gamma Result Activity' (dpm/100 cm2)

Fraction ofOpDCGL Measurement Population Measurement ID OpSOF dpm/100 cm2 Co-60 Cs-137 Eu-152 Eu-154 Sr-90 Co-60 Cs-137 Eu-152 Eu-154 Sr-90 s

SLI 4813 3.44E+02 4.42E+03 2.93E+0l l.50E+0l 2.22E+03 0.0219 0.0662 0.0009 0.0005 0.0206 0.1100 s

SL2 4847 3.46E+02 4.46E+03 2.95E+0l l.5lE+0l 2.24E+03 0.0221 0.0667 0.0009 0.0005 0.0207 0.1108 s

SL3 4534 3.24E+02 4.l7E+03 2.76E+0l l.41E+0l 2.09E+03 0.0206 0.0624 0.0008 0.0004 0.0194 0.1036 s

SL4 4663 3.33E+02 4.29E+03 2.84E+0l l.45E+0l 2.l5E+03 0.0212 0.0642 0.0008 0.0005 0.0199 0.1066 s

SL5 4811 3.44E+02 4.42E+03 2.93E+0l l.50E+0l 2.22E+03 0.0219 0.0662 0.0009 0.0005 0.0206 0.1100 s

SL6 5029 3.59E+02 4.62E+03 3.06E+0l l.57E+0l 2.32E+03 0.0229 0.0692 0.0009 0.0005 0.0215 0.1150 s

SL7 5108 3.65E+02 4.70E+03 3.llE+0l l.59E+0l 2.36E+03 0.0232 0.0703 0.0009 0.0005 0.0218 0.1168 s

SL8 3409 2.44E+02 3.13E+03 2.08E+0l l.06E+0l l.57E+03 0.0155 0.0469 0.0006 0.0003 0.0146 0.0779 s

SL9 5224 3.73E+02 4.80E+03 3.l8E+0l l.63E+0l 2.41E+03 0.0238 0.0719 0.0009 0.0005 0.0223 0.1194 s

SLI0 4709 3.36E+02 4.33E+03 2.87E+0l l.47E+0l 2.l7E+03 0.0214 0.0648 0.0008 0.0005 0.0201 0.1076 s

SLll 5101 3.64E+02 4.69E+03 3.llE+0l l.59E+0l 2.35E+03 0.0232 0.0702 0.0009 0.0005 0.0218 0.1166 s

SLl2 5019 3.58E+02 4.61E+03 3.06E+0l l.56E+0l 2.32E+03 0.0228 0.0691 0.0009 0.0005 0.0214 0.1147 s

SLl3 5017 3.58E+02 4.61E+03 3.05E+0l l.56E+0l 2.32E+03 0.0228 0.0690 0.0009 0.0005 0.0214 0.1147 s

SLl4 4993 3.57E+02 4.59E+03 3.04E+0l l.56E+0l 2.30E+03 0.0227 0.0687 0.0009 0.0005 0.0213 0.1141 s

SLl5 5237 3.74E+02 4.81E+03 3.l9E+0l l.63E+0l 2.42E+03 0.0238 0.0721 0.0009 0.0005 0.0224 0.1197 s

SLl6 5000 3.57E+02 4.60E+03 3.04E+0l l.56E+0l 2.31E+03 0.0227 0.0688 0.0009 0.0005 0.0214 0.1143 s

SLl7 5183 3.70E+02 4.76E+03 3.l6E+0l l.62E+0l 2.39E+03 0.0236 0.0713 0.0009 0.0005 0.0221 0.1185 s

SLl8 5252 3.75E+02 4.83E+03 3.20E+0l l.64E+0l 2.42E+03 0.0239 0.0723 0.0009 0.0005 0.0224 0.1201 s

SLl9 5480 3.91E+02 5.04E+03 3.34E+0l l.71E+0l 2.53E+03 0.0249 0.0754 0.0010 0.0005 0.0234 0.1253 s

SL20 5119 3.66E+02 4.71E+03 3.l2E+0l l.60E+0l 2.36E+03 0.0233 0.0704 0.0009 0.0005 0.0219 0.1170 s

SL21 5250 3.75E+02 4.83E+03 3.20E+0l l.64E+0l 2.42E+03 0.0239 0.0723 0.0009 0.0005 0.0224 0.1200 s

SL22 J 5141 3.67E+02 4.73E+03 3.13E+0l l.60E+0l 2.37E+03 0.0234 0.0708 0.0009 0.0005 0.0220 0.1175 s

SL23 5279 3.77E+02 4.85E+03 3.21E+0l l.65E+0l 2.44E+03 0.0240 0.0727 0.0009 0.0005 0.0226 0.1207 s

SL24 5237 3.74E+02 4.81E+03 3.l9E+0l l.63E+0l 2.42E+03 0.0238 0.0721 0.0009 0.0005 0.0224 0.1197 22

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SUR VEY UNIT S2-011-103 Measurement Gamma Result Population Measurement ID dpm/100 cm2 s

SL25 5057 s

SL26 4971 s

SL27 4871 s

SL28 4907 s

SL29 5046 s

SL30 5726 Q

SL4QC 4521 Q

SL23 QC 5320 (1) Sr-90 activity inferred from Cs-137.

Activity' (dpm/100 cm2)

Co-60 Cs-137 Eu-152 Eu-154 3.61E+02 4.65E+03 3.08E+0l l.58E+0l 3.55E+02 4.57E+03 3.03E+0l l.55E+0l 3.48E+02 4.48E+03 2.97E+0l l.52E+0l 3.50E+02 4.51E+03 2.99E+0l l.53E+0l 3.60E+02 4.64E+03 3.07E+0l l.57E+0l 4.09E+02 5.26E+03 3.49E+0l l.78E+0l 3.23E+02 4.l6E+03 2.75E+0l l.41E+0l 3.80E+02 4.89E+03 3.24E+0l l.66E+0l 23

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LACROSSESOLUTIONS Fraction ofOpDCGL Measurement Sr-90 Co-60 Cs-137 Eu-152 Eu-154 Sr-90 OpSOF 2.33E+03 0.0230 0.0696 0.0009 0.0005 0.0216 0.1156 2.29E+03 0.0226 0.0684 0.0009 0.0005 0.0212 0.1136 2.25E+03 0.0222 0.0670 0.0009 0.0005 0.0208 0.1113 2.26E+03 0.0223 0.0675 0.0009 0.0005 0.0210 0.1122 2.33E+03 0.0230 0.0694 0.0009 0.0005 0.0216 0.1153 2.64E+03 0.0260 0.0788 0.0010 0.0006 0.0245 0.1309 2.09E+03 0.0206 0.0622 0.0008 0.0004 0.0193 0.1033 2.46E+03 0.0242 0.0732 0.0009 0.0005 0.0227 0.1216

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 24 ATTACHMENT 3 SIGN TEST

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 25 Table 16 Survey Unit S2-011-103 Sign Test SOF 1-Ws Sign (Ws) 1 0.1100 0.89

+1 2

0.1108 0.89

+1 3

0.1036 0.90

+1 4

0.1066 0.89

+1 5

0.1100 0.89

+1 6

0.1150 0.89

+1 7

0.1168 0.88

+1 8

0.0779 0.92

+1 9

0.1194 0.88

+1 10 0.1076 0.89

+1 11 0.1166 0.88

+1 12 0.1147 0.89

+1 13 0.1147 0.89

+1 14 0.1141 0.89

+1 15 0.1197 0.88

+1 16 0.1143 0.89

+1 17 0.1185 0.88

+1 18 0.1201 0.88

+1 19 0.1253 0.87

+1 20 0.1170 0.88

+1 21 0.1200 0.88

+1 22 0.1207 0.88

+1 23 0.1197 0.88

+1 24 0.1156 0.88

+1 25 0.1136 0.89

+1 26 0.1113 0.89

+1 27 0.1122 0.89

+1 28 0.1153 0.88

+1 29 0.1309 0.87

+1 Number of positive differences (S+)

29 Critical Value 19 Survey Unit Meets the Acceptance Criteria

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 26 ATTACHMENT 4 QUALITY CONTROL ASSESSMENT

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SUR VEY UNIT S2-011-103 Table 16-3-Survey Unit S2-011-103 QC Assessment Standard Measurement Replicate I

Activity

+20%

-20%

Activity Acceptable ID Value ID Value (YIN)

SIA 4663 5596 3731 SIA QC 4521 y

SL23 5279 6335 4223 SL23 QC 5320 y

Comments/Corrective Actions: The replicate measurement results are in acceptable The acceptance criteria for replicate static measurements and is that the agreement same conclusion is reached for each measurement. This is defined as the replicate measurement being within 20% of the standard measurement. fu cases where the replicate measurement is not within 20% of the standard measurement, but both measurements are below the Operational DCGL, there is an acceptable agreement.

27

FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 28 ATTACHMENT 5 GRAPHICAL PRESENTATIONS

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 29 Figure 16 Quantile Plot for Gross Gamma Activity

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 30 Figure 16 Histogram for Gross Gamma Activity

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FSS RELEASE RECORD - REVISION 1 CIRCULATING WATER INTAKE PIPE SURVEY UNIT S2-011-103 31 Figure 16 Retrospective Power Curve for Survey Unit S2-011-103

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LACROSSESOLUTIONS Probability that the urvey -nit Passes 1.0 0.8 0.6 0.4 0.2 0.0 1)%

3)%

50%

-0%

90% 1 JO% 110%

130%

15 0%

True urve_

• nit oncentration (percent of D GL)