ML20006D466

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Lacrossesolutions, LLC - Final Status Survey Report - Phase 2, Storm Drain 1, Survey Unit S3-012-109 a
ML20006D466
Person / Time
Site: La Crosse  File:Dairyland Power Cooperative icon.png
Issue date: 12/12/2019
From: Coffey L
LaCrosseSolutions
To:
Office of Nuclear Material Safety and Safeguards
Shared Package
ML20006D756 List:
References
LC-2019-0051 S3-012-109 A
Download: ML20006D466 (31)
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LA CROSSE BOILING WATER REACTOR FINAL STATUS SURVEY RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A 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 ...................................................................................................................... 12
7. SURVEY RESULTS .......................................................................................................................................... 13
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 ............................................................................................................................... 23 ATTACHMENT 4 - QUALITY CONTROL ASSESSMENT ...................................................................................... 25 ATTACHMENT 5 - GRAPHICAL PRESENTATIONS ............................................................................................. 27 2

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A 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/Buried Pipe Surrogate Ratio ............................................................................................................ 9 Table 5 Investigation Levels ................................................................................................................................ 11 Table 5 Synopsis of Survey Design...................................................................................................................... 12 Table 7 Summary of Systematic, Judgmental, and QC Measurements ........................................................... 15 Table 7 Basic Statistical Properties of the Systematic Measurement Population ............................................ 15 Table 16 Survey Unit S3-012-109 A Static Measurements Data Assessment .................................................. 22 Table 16 Survey Unit S3-012-109 A Sign Test ................................................................................................... 24 Table 16 Survey Unit S3-012-109 A QC Assessment ......................................................................................... 26 LIST OF FIGURES Figure 16 Survey Unit S3-012-109 A Map............................................................... Error! Bookmark not defined.

Figure 16 Quantile Plot for Gross Gamma Activity .......................................................................................... 28 Figure 16 Histogram for Gross Gamma Activity ............................................................................................... 29 Figure 16 Retrospective Power Curve for Survey Unit S3-012-109 A.............................................................. 30 3

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A 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 PVC Polyvinyl Chloride 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 4

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A

1. EXECUTIVE

SUMMARY

This Final Status Survey (FSS) Release Record for survey unit S3-012-109 A, Storm Drain 1 (SD1), 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 S3-012-109 A has a MARSSIM classification of 3. 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 (20) static gamma measurements were acquired from the survey unit. The data assessment results for survey unit S3-012-109 A 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 1.1569 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 0.1204. This SOF equates to a dose for the survey unit of 3.0112 mrem/yr.

2. SURVEY UNIT DESCRIPTION S3-012-109 A is an impacted Class 3 buried pipe survey unit. The survey unit consists of the interior surface of the SD1 pipe, which is a 10 Internal Diameter (ID) Polyvinyl Chloride (PVC) pipe that is used to direct storm water out of the roadway south of the Back-Up Control Center (BCC) building. The total length of pipe is approximately 195 feet (59.4 m). The total interior surface area of SD1 is 47.4 m2 (473,991 cm2). Refer to Attachment 1 of this report for a figure depicting survey unit S3-012-109 A.
3. CLASSIFICATION BASIS Based on the La Crosse Boiling Water Reactor Historical Site Assessment (HSA)

(Reference 6), the SD1 was identified as a Class 3 system.

5

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A 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 S3-012-109 A was determined to be Class 3.

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 S3-012-109 A 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 6

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A 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 Fraction of Total Activity Radionuclide (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).

7

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A 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 SD1 are provided in Table 4-3.

Table 4 Base Case DCGLs for Buried Pipe Group DCGLBP Radionuclide (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 8

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Table 4 Operational DCGLs for Buried Pipe Group OpDCGLBP Radionuclide (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 minimum detectable concentration (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 S3-012-109 A 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/Buried Pipe Surrogate Ratio Radionuclides Ratio Sr-90/Cs-137 0.502 9

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A The equation for calculating a surrogate DCGL is as follows:

Equation 1 1

=

1 2 3

[( ) + ( ) + ( ) + ( )]

2 3 Where: DCGLSur = Surrogate radionuclide DCGL DCGL2,3n = DCGL for radionuclides to be represented by the surrogate Rn = Ratio of concentration (or nuclide mixture fraction) of radionuclide n to surrogate radionuclide Using the Operational DCGLs presented in Table 4-3 and the ratio from Table 5-1, the following surrogate calculation was performed:

Equation 2 1

(137) =

1 0.502

[(6.68 + 04 )+( )]

(137) 1.08 + 05(90)

= 5.10 + 04 /100 2 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 0.919 0.006 0.003

[( )+( ) + (3.44 + 04 ) + (3.20 + 04 )]

1.57 + 04(60) 5.10 + 04137 (152) (154)

= 4.37 + 04 /100 2 The action level for survey unit S3-012-109 A 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 SD1, 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 10

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Water Discharge Pipes for the LaCrosse Boiling Water Reactor (Reference 12) was written 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 10 ID pipe, each measurement has a true Field-of-View (FOV) of 2,432 cm2.

The SD1 contains 195 linear feet of 10 ID PVC piping, which equates to a surface area of 47.4 m2 (473,991 cm2). For survey unit S3-012-109 A, 10% survey coverage was selected.

Therefore, a total of at least twenty (20) distinct measurements over the entire accessible pathway of the piping system were required.

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. One (1) replicate static measurement was selected for Quality Control (QC) analysis for the FSS of this survey unit.

For this Class 3 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.

Table 5 Investigation Levels Direct Investigation Classification Scan Investigation Levels Levels

>Operational DCGL or >MDCscan if Class 3 MDCscan is greater than Operational >Operational DCGL DCGL 11

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Table 5-3 provides a synopsis of the survey design for survey unit S3-012-109 A.

Table 5 Synopsis of Survey Design Feature Design Criteria Basis Survey Unit Surface 195 of 10 inner diameter 47.4 m2 (473,991 cm2)

Area PVC pipe Number of Systematic 20 10% coverage Measurements (N)

Co-60: 1.57E+04 Sr-90: 1.08E+05 Operational DCGLs for Operational DCGLs buried pipe, Cs-137: 6.68E+04 (dpm/100 cm2) LTP Chapter 5, Table 5-8, Eu-152: 3.44E+04 Release Record Table 4-3 Eu-154: 3.20E+04 4.37E+04 dpm/100 cm2 Gross Gamma Operational Action Level DCGL, Equation 3 Investigation Level >Operational DCGL LTP Chapter 5, Table 5-15 Scan Areal Coverage N/A LTP Section 5.7.1.8 QC 1 replicate measurement LTP Chapter 5, Section 5.9 Number of 1 Per Sample Plan Judgmental 2 Actual Number Obtained Measurements Non-parametric Sign Test LTP Section 5.6.4.2 Statistical Test

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 August 1, 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 12

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A of the job. The survey-required field activities were performed during normal working hours and concluded on August 10, 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 SD1 were not representative of true background levels. A background study was performed by collecting measurements on a buried piece of 10 ID PVC pipe. The result of the background study for the 10 ID PVC pipe was an average background value of 3,581 cpm. This is the value subtracted from each measurement for compliance.

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 twenty (20) 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 2,423 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.

Two (2) judgmental static measurements were collected during implementation of FSS, in accordance with the sample plan. One measurement was taken at each end of the pipe: one at the manhole access end, and one at the discharge point where elevated readings were encountered.

The implementation of survey specific QC measures included the collection of one (1) 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 C1 C2 Cn

.......... .. 1 DCGL1 DCGL 2 DCGL n 13

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A 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. Three locations in S3-012-109 (SD1) were identified to be elevated. The investigation results are discussed in section 9 of this report. The SOF (based on the OpDCGLBP) 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 (20) static measurements that were acquired using the Ludlum Model 2350-1 paired to a Model 44-10 detector. In total, twenty-three (23) static measurements were collected, including the systematic, 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 S3-012-109 A are provided in Attachment 2.

14

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Table 7 Summary of Systematic, Judgmental, and QC Measurements Total Number of Systematic Measurements 20 Number of Quality Control Measurements 1 Number of Judgmental Measurements 2 Total Number of Measurements 23 Mean Systematic Measurement SOF (1) 0.5290 Max Individual Systematic Measurement SOF (1) 1.1383 Number of Systematic Measurements with SOF > 1 (1) 3 (1) Based on the OpDCGLBP Table 7 Basic Statistical Properties of the Systematic Measurement Population Mean Median Max Min Std. Dev. BcDCGL Avg Avg Dose ROC (dpm/100 (dpm/100 (dpm/100 (dpm/100 (dpm/100 (dpm/100 BcSOF per per ROC cm2) cm2) cm2) cm2) cm2) cm2) ROC Co-60 1.79E+03 1.31E+03 3.61E+03 9.80E+02 9.42E+02 7.50E+04 0.0239 0.5980 Cs-137 2.31E+04 1.69E+04 4.65E+04 1.26E+04 1.21E+04 3.18E+05 0.0726 1.8154 Eu-152 1.53E+02 1.12E+02 3.08E+02 8.36E+01 8.03E+01 1.64E+05 0.0009 0.0233 Eu-154 7.83E+01 5.72E+01 1.58E+02 4.28E+01 4.11E+01 1.52E+05 0.0005 0.0129 Sr-90 1.16E+04 8.47E+03 2.34E+04 6.33E+03 6.08E+03 5.16E+05 0.0225 0.5616 SUM 0.1204 3.0112 The mean SOF for the SD1 pipe, based on the mean concentration for each ROC as measured by the systematic measurement population when compared against the DCGLBP, is 0.1204. This SOF equates to a dose of 3.0112 mrem/yr.

8. QUALITY CONTROL The implementation of survey specific QC measures included the collection of (1) replicate static measurement 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 the replicate measurement is not within 20% of the standard measurement, but both measurements are below the Operational DCGL, there is an acceptable agreement. The QC replicate measurement did fall within the 20% criteria, and both the standard and replicate measurement were below the Operational DCGL. No further action was deemed necessary, and there is an acceptable agreement between standard and replicate results. Refer to Attachment 4 for QC analysis results.

15

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A

9. INVESTIGATIONS AND RESULTS Investigations were performed at a bend in the pipe where the collected readings began to increase. ISOCS data was collected above the ground at measured locations where the pipe elevated readings occurred to identify any influence from the soil surrounding the pipe. K-40 was the only radionuclide identified by the ISOCS measurement. Collection of soil samples at the same points was performed for gamma spectroscopy analysis. A total of sixteen (16) samples were analyzed, with Cs-137 identified in one sample at 0.10 pCi/g. K-40 was identified in all samples with concentrations ranging from 4 to 8.6 pCi/g.

Additionally, in-situ readings were taken inside the pipe with a BNC SAM 940 Nuclide Identifier. Cs-137 was not identified with the BNC SAM 940 instrument. After a review of the data, it was verified to be a natural radionuclide anomaly causing slightly higher than normal readings but less than the DCGLBP.

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.
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 3. The survey design had adequate power as indicated by the Retrospective Power Curve (see Attachment 5).

Seventeen (17) of the total twenty (20) systematic measurements were less than a SOF of one (1) when compared to the OpDCGLBP. No measurement exceeded the DCGLBP.

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 16

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A passes the unrestricted release criteria, thus, the null hypothesis is rejected. The Sign Test is provided as Attachment 3.

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 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 S3-012-109 A 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 3. Therefore, in accordance with LTP Section 5.11, the survey unit meets the release criteria.

The dose contribution from survey unit S3-012-109 A is 3.0112 mrem/yr TEDE, based on the average concentration of the ROC in measurements used for non-parametric statistical testing (mean SOF).

Survey unit S3-012-109 A 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 17

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A

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
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 Attachment 1 - Figures and Maps Attachment 2 - Measurement Data Attachment 3 - Sign Test Attachment 4 - Quality Control Assessment Attachment 5 - Graphical Presentations 18

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A ATTACHMENT 1 FIGURES AND MAPS 19

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Figure 16 Survey Unit S3-012-109 A Map 20

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A ATTACHMENT 2 MEASUREMENT DATA 21

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Table 16 Survey Unit S3-012-109 A Static Measurements Data Assessment Gamma Measur Activity1 (dpm/100 cm2) Fraction of OpDCGL Measurement Result Measurem ement Population dpm/100 ent OpSOF ID Co-60 Cs-137 Eu-152 Eu-154 Sr-90 Co-60 Cs-137 Eu-152 Eu-154 Sr-90 cm2 S 1 13428 9.59E+02 1.23E+04 8.18E+01 4.18E+01 6.20E+03 0.0611 0.1848 0.0024 0.0013 0.0574 0.3070 S 2 13534 9.67E+02 1.24E+04 8.24E+01 4.22E+01 6.25E+03 0.0616 0.1863 0.0024 0.0013 0.0578 0.3094 S 3 13723 9.80E+02 1.26E+04 8.36E+01 4.28E+01 6.33E+03 0.0624 0.1889 0.0024 0.0013 0.0586 0.3137 S 4 13797 9.85E+02 1.27E+04 8.40E+01 4.30E+01 6.37E+03 0.0628 0.1899 0.0024 0.0013 0.0590 0.3154 S 5 15397 1.10E+03 1.42E+04 9.37E+01 4.80E+01 7.11E+03 0.0700 0.2119 0.0027 0.0015 0.0658 0.3520 S 6 15340 1.10E+03 1.41E+04 9.34E+01 4.78E+01 7.08E+03 0.0698 0.2111 0.0027 0.0015 0.0656 0.3507 S 7 17663 1.26E+03 1.62E+04 1.08E+02 5.50E+01 8.15E+03 0.0803 0.2431 0.0031 0.0017 0.0755 0.4038 S 8 18861 1.35E+03 1.73E+04 1.15E+02 5.88E+01 8.70E+03 0.0858 0.2596 0.0033 0.0018 0.0806 0.4312 S 9 18656 1.33E+03 1.72E+04 1.14E+02 5.81E+01 8.61E+03 0.0849 0.2568 0.0033 0.0018 0.0797 0.4265 S 10 16448 1.17E+03 1.51E+04 1.00E+02 5.13E+01 7.59E+03 0.0748 0.2264 0.0029 0.0016 0.0703 0.3760 S 11 18877 1.35E+03 1.74E+04 1.15E+02 5.88E+01 8.71E+03 0.0859 0.2598 0.0033 0.0018 0.0807 0.4315 S 12 14421 1.03E+03 1.33E+04 8.78E+01 4.49E+01 6.66E+03 0.0656 0.1985 0.0026 0.0014 0.0616 0.3297 S 13 16743 1.20E+03 1.54E+04 1.02E+02 5.22E+01 7.73E+03 0.0762 0.2304 0.0030 0.0016 0.0716 0.3828 S 14 18040 1.29E+03 1.66E+04 1.10E+02 5.62E+01 8.33E+03 0.0821 0.2483 0.0032 0.0018 0.0771 0.4124 S 15 34619 2.47E+03 3.18E+04 2.11E+02 1.08E+02 1.60E+04 0.1575 0.4765 0.0061 0.0034 0.1479 0.7914 S 16 35120 2.51E+03 3.23E+04 2.14E+02 1.09E+02 1.62E+04 0.1598 0.4834 0.0062 0.0034 0.1501 0.8028 S 17 39388 2.81E+03 3.62E+04 2.40E+02 1.23E+02 1.82E+04 0.1792 0.5421 0.0070 0.0038 0.1683 0.9004 S 18 48285 3.45E+03 4.44E+04 2.94E+02 1.50E+02 2.23E+04 0.2197 0.6645 0.0085 0.0047 0.2063 1.1038 S 19 50608 3.61E+03 4.65E+04 3.08E+02 1.58E+02 2.34E+04 0.2302 0.6965 0.0090 0.0049 0.2163 1.1569 S 20 46118 3.29E+03 4.24E+04 2.81E+02 1.44E+02 2.13E+04 0.2098 0.6347 0.0082 0.0045 0.1971 1.0543 J 21 J 13624 9.73E+02 1.25E+04 8.30E+01 4.25E+01 6.29E+03 0.0620 0.1875 0.0024 0.0013 0.0582 0.3115 J 22 J 32666 2.33E+03 3.00E+04 1.99E+02 1.02E+02 1.51E+04 0.1486 0.4496 0.0058 0.0032 0.1396 0.7467 Q 21 QC 18602 1.33E+03 1.71E+04 1.13E+02 5.80E+01 8.59E+03 0.0846 0.2560 0.0033 0.0018 0.0795 0.4252 1: Sr-90 activity is inferred from Cs-137.

22

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A ATTACHMENT 3 SIGN TEST 23

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Table 16 Survey Unit S3-012-109 A Sign Test SOF

  1. 1-Ws Sign (Ws) 1 0.3070 0.69 +1 2 0.3094 0.69 +1 3 0.3137 0.69 +1 4 0.3154 0.68 +1 5 0.3520 0.65 +1 6 0.3507 0.65 +1 7 0.4038 0.60 +1 8 0.4312 0.57 +1 9 0.4265 0.57 +1 10 0.3760 0.62 +1 11 0.4315 0.57 +1 12 0.3297 0.67 +1 13 0.3828 0.62 +1 14 0.4124 0.59 +1 15 0.7914 0.21 +1 16 0.8028 0.20 +1 17 0.9004 0.10 +1 18 1.1038 (0.10) -1 19 1.1569 (0.16) -1 20 1.0543 (0.05) -1 Number of positive differences (S+) 17 Critical Value 14 Survey Unit Meets the Acceptance Criteria 24

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A ATTACHMENT 4 QUALITY CONTROL ASSESSMENT 25

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Table 16 Survey Unit S3-012-109 A QC Assessment Standard Measurement Replicate Activity Activity Acceptable

+20% -20%

ID Value ID Value (Y/N) 21 J 13624 16349 10900 21 QC 18602 N 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. In 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.

26

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A ATTACHMENT 5 GRAPHICAL PRESENTATIONS 27

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Figure 16 Quantile Plot for Gross Gamma Activity 28

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Figure 16 Histogram for Gross Gamma Activity 29

FSS RELEASE RECORD STORM DRAIN 1 SURVEY UNIT S3-012-109 A Figure 16 Retrospective Power Curve for Survey Unit S3-012-109 A 30

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