ML20029D896
| ML20029D896 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 01/28/2020 |
| From: | Altic N Oak Ridge Institute for Science & Education |
| To: | John Hickman Division of Decommissioning, Uranium Recovery and Waste Programs |
| J HICKMAN | |
| References | |
| DCN 5271-SR-04-0, DE-SC0014664 | |
| Download: ML20029D896 (54) | |
Text
P.O. Box 117 Oak Ridge, TN 37831
- https://orise.orau.gov January 28, 2020 Mr. John Hickman U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards Division of Decommissioning, Uranium Recovery, and Waste Programs Reactor Decommissioning Branch Mail Stop: T8F5 11545 Rockville Pike Rockville, MD 20852
SUBJECT:
DOE Contract No. DE-SC0014664 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR SELECT PENETRATIONS AND EMBEDDED PIPING IN THE CONTAINMENT AND AUXILIARY BUILDINGS AT THE ZION NUCLEAR POWER STATION, ZION, ILLINOIS DOCKET NOs. 50-295 and 50-304; RFTA NO.18-004; DCN 5271-SR-04-0
Dear Mr. Hickman:
The Oak Ridge Institute for Science and Education (ORISE) is pleased to provide the enclosed report detailing the independent confirmatory survey activities associated with select penetrations in the Containment and Auxiliary Buildings at the Zion Nuclear Power Station in Zion, Illinois. This report provides the summary and results of ORISE on-site activities performed during the period of June 4-7, 2018.
You may contact me at 865.574.6273 or Erika Bailey at 865.576.6659 if you have any questions.
Sincerely, Nick A. Altic, CHP Health Physicist/Project Manager ORISE NAA:tb electronic distribution:
B. Lin, NRC R. Edwards, NRC K. Conway, NRC E. Bailey, ORISE D. Hagemeyer, ORISE File/5271
INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR SELECT PENETRATIONS AND EMBEDDED PIPING IN THE CONTAINMENT AND AUXILIARY BUILDINGS AT THE ZION NUCLEAR POWER STATION, ZION, ILLINOIS N. A. Altic, CHP ORISE FINAL REPORT Prepared for the U.S. Nuclear Regulatory Commission January 2020 Further dissemination authorized to NRC only; other requests shall be approved by the originating facility or higher NRC programmatic authority.
ORAU provides innovative scientific and technical solutions to advance research and education, protect public health and the environment and strengthen national security. Through specialized teams of experts, unique laboratory capabilities and access to a consortium of more than 100 major Ph.D.-granting institutions, ORAU works with federal, state, local and commercial customers to advance national priorities and serve the public interest. A 501(c) (3) nonprofit corporation and federal contractor, ORAU manages the Oak Ridge Institute for Science and Education (ORISE) for the U.S. Department of Energy (DOE). Learn more about ORAU at www.orau.org.
NOTICES The opinions expressed herein do not necessarily reflect the opinions of the sponsoring institutions of Oak Ridge Associated Universities.
This report was prepared as an account of work sponsored by the United States Government.
Neither the United States Government nor the U.S. Department of Energy, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe on privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, mark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement or recommendation, or favor by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof.
Zion Containment and Auxiliary Penetrations 5271-SR-04-0 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR SELECT PENETRATIONS AND EMBEDDED PIPING IN THE CONTAINMENT AND AUXILIARY BUILDINGS AT THE ZION NUCLEAR POWER STATION, ZION, ILLINOIS FINAL REPORT Prepared by N. A. Altic, CHP ORISE January 2020 Prepared for the U.S. Nuclear Regulatory Commission This document was prepared for the U.S. Nuclear Regulatory Commission by the Oak Ridge Institute for Science and Education (ORISE) through interagency agreement number 31310018N0014 with the U.S. Department of Energy (DOE). ORISE is managed by Oak Ridge Associated Universities under DOE contract number DE-SC0014664.
Zion Containment and Auxiliary Penetrations 5271-SR-04-0 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR SELECT PENETRATIONS AND EMBEDDED PIPING IN THE CONTAINMENT AND AUXILIARY BUILDINGS AT THE ZION NUCLEAR POWER STATION, ZION, ILLINOIS Prepared by:
Date:
N. A. Altic, CHP, Health Physicist/Project Manager ORISE Reviewed by:
Date:
P. H. Benton, Quality Manager ORISE Reviewed by:
Date:
W. F. Smith, Senior Chemist ORISE Reviewed and approved for release by:
Date:
E. N. Bailey, Survey and Technical Projects Group Manager ORISE FINAL REPORT JANUARY 2020 1/28/2020 1/28/2020 1/28/2020 1/28/2020
Zion Containment and Auxiliary Penetrations i
5271-SR-04-0 CONTENTS FIGURES.......................................................................................................................................................... iii TABLES............................................................................................................................................................. iii ACRONYMS.................................................................................................................................................... iv EXECUTIVE
SUMMARY
.............................................................................................................................. v
- 1. INTRODUCTION....................................................................................................................................... 1
- 2. SITE DESCRIPTION................................................................................................................................. 2 2.1 Unit 1 and 2 Containment Building Penetrations and Embedded Piping................................ 3 2.2 Auxiliary Building Penetrations....................................................................................................... 3
- 3. DATA QUALITY OBJECTIVES............................................................................................................. 4 3.1 State the Problem.............................................................................................................................. 4 3.2 Identify the Decision/Objective..................................................................................................... 5 3.3 Identify Inputs to the Decision/Objective.................................................................................... 5 3.3.1 Radionuclides of Concern and Release Guidelines.............................................................. 6 3.4 Define the Study Boundaries........................................................................................................... 8 3.5 Develop a Decision Rule.................................................................................................................. 9 3.6 Specify Limits on Decision Errors............................................................................................... 11 3.6.1 Hypothesis Testing................................................................................................................. 11 3.6.2 Field and Analytical MDCs................................................................................................... 12 3.7 Optimize the Design for Obtaining Data.................................................................................... 12
- 4. PROCEDURES.......................................................................................................................................... 12 4.1 Reference System............................................................................................................................ 13 4.2 Surface Scans.................................................................................................................................... 13 4.3 Surface Activity Measurements..................................................................................................... 13 4.4 Miscellaneous Sampling.................................................................................................................. 14
- 5. SAMPLE ANALYSIS AND DATA INTERPRETATION............................................................... 15
- 6. FINDINGS AND RESULTS................................................................................................................... 16 6.1 Unit 1 Containment........................................................................................................................ 16 6.1.1 Surface Scans........................................................................................................................... 16 6.1.2 Surface Activity Measurements............................................................................................. 16 6.1.3 Comparison of FSS and Confirmatory Data Sets.............................................................. 17 6.1.4 ROC Activity in the Swipe Sample...................................................................................... 18 6.2 Unit 2 Containment........................................................................................................................ 18 6.2.1 Surface Scans........................................................................................................................... 18
Zion Containment and Auxiliary Penetrations ii 5271-SR-04-0 6.2.2 Surface Activity Measurements............................................................................................ 19 6.2.3 Comparison of FSS and Confirmatory Data Sets.............................................................. 19 6.3 Auxiliary Building............................................................................................................................ 20
- 7.
SUMMARY
AND CONCLUSIONS...................................................................................................... 21
- 8. REFERENCES........................................................................................................................................... 22 APPENDIX A: FIGURES APPENDIX B: DATA TABLES APPENDIX C: SURVEY AND ANALYTICAL PROCEDURES APPENDIX D: MAJOR INSTRUMENTATION
Zion Containment and Auxiliary Penetrations iii 5271-SR-04-0 FIGURES Figure 2.1. ZNPS Overview (adapted from ZS 2018a)................................................................................ 2 Figure 2.2. ZNPS Containment and Auxiliary Buildings (Google Earth)................................................. 3 Figure 3.1. FSS Surface Activity Length Profile for Penetration P324 in the Unit 2 Containment Building............................................................................................................................................................. 10 Figure 4.1. Sample Size Determination Using VSP.................................................................................... 14 TABLES Table 3.1. FSS Confirmatory Survey Decision Process............................................................................... 5 Table 3.2. ZS Embedded Piping DCGLs...................................................................................................... 6 Table 3.3. ZS Penetration DCGLs.................................................................................................................. 7 Table 3.4. Penetrations Selected for Confirmatory Survey.......................................................................... 9 Table 6.1. Summary of Unit 1 Penetration Scan Range............................................................................. 16 Table 6.2. Summary of Confirmatory Measurements in Unit 1 Penetrations......................................... 16 Table 6.3. Students t-Test Summary for Unit 1 Penetrations.................................................................. 17 Table 6.4. ROC Activity in Miscellaneous Sample 5271M0038 Swipe.................................................... 18 Table 6.5. Summary of Unit 2 Penetration Scan Range............................................................................. 19 Table 6.6. Summary of Confirmatory Measurements in Unit 2 Penetrations......................................... 19 Table 6.7. Students t-Test Summary for Unit 2 Penetrations.................................................................. 20 Table 6.8. Confirmatory Measurements in the Auxiliary Building........................................................... 21
Zion Containment and Auxiliary Penetrations iv 5271-SR-04-0 ACRONYMS AA alternate action AF area factor Bkg background cpm counts per minute CsI cesium iodide DCGL derived concentration guideline level DCGLBC Base Case DCGL DCGLEMC elevated measurement comparison DCGL DCGLGROSS gross activity DCGL DCGLOp Operational DCGL DOE U.S. Department of Energy dpm disintegrations per minute DQO data quality objective DS decision statement EPA U.S. Environmental Protection Agency Exelon Exelon Generation Company FSS final status survey HS hot spot LTP license termination plan MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDC minimum detectable concentration mL milliliter mrem/yr millirem per year NaI sodium iodide NIST National Institute of Standards and Technology NRC U.S. Nuclear Regulatory Commission ORAU Oak Ridge Associated Universities ORISE Oak Ridge Institute for Science and Education pCi/g picocuries per gram pCi/m2 picocuries per square meter PPE personal protective equipment PSQ principal study question ROC radionuclide of concern SOF sum of fractions SU survey unit TAP total absorption peak TEDE total effective dose equivalent VSP Visual Sample Plan WWTF Waste Water Treatment Facility ZNPS Zion Nuclear Power Station ZS ZionSolutions, LLC
Zion Containment and Auxiliary Penetrations v
5271-SR-04-0 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR SELECT PENETRATIONS AND EMBEDDED PIPING IN THE CONTAINMENT AND AUXILIARY BUILDINGS AT THE ZION NUCLEAR POWER STATION, ZION, ILLINOIS EXECUTIVE
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) requested that the Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities of select remaining embedded piping and penetrations at the Zion Nuclear Power Station (ZNPS). The survey activities were conducted during the period of June 4-7, 2018, and included gamma surface scans, direct gamma measurements, and miscellaneous sampling. Direct gamma measurements were collected at randomly selected locations inside the Unit 1 and Unit 2 Containment penetrations and were compared with the corresponding FSS measurement.
None of the piping/penetration interior direct measurements exceeded the most restrictive Base Case derived concentration guideline level (DCGLBC) in any of the areas investigated as part of the confirmatory survey. A cloth wipe of the penetration P035 interior identified the presence of Am-241, which was deselected from the final status survey (FSS) analysis based on an insignificant dose contribution. The Am-241 activity on the wipe, which represents the removable radionuclide of concern (ROC) portion, was at least an order of magnitude less than the more predominant gamma-emitters, Cs-137 and Co-60.
The confirmatory survey did not generate sufficient evidence to conclude that the FSS and confirmatory measurements were statistically different. The difference in the sodium iodide (NaI) detector response profile for one measurement pair in penetration P323 may be explained by loose debris containing contamination that was present inside of the penetration during FSS, but was not present during the confirmatory survey. However, additional evaluation is not recommended given the low magnitude of the confirmatory survey measurements relative to the DCGLBC.
The results of the confirmatory surveys conducted by ORISE did not identify any issues that would preclude the FSS data from demonstrating compliance with the release criteria.
Zion Containment and Auxiliary Penetrations 1
5271-SR-04-0 INDEPENDENT CONFIRMATORY SURVEY
SUMMARY
AND RESULTS FOR SELECT PENETRATIONS AND EMBEDDED PIPING IN THE CONTAINMENT AND AUXILIARY BUILDINGS AT THE ZION NUCLEAR POWER STATION, ZION, ILLINOIS
- 1. INTRODUCTION The Zion Nuclear Power Station (ZNPS) consists of two reactors, Units 1 and 2, which operated commercially from 1973 to 1997 and 1974 to 1996, respectively. Cessation of nuclear operations was certified in 1998 after both reactor units were defueled and the fuel assemblies had been placed in the spent fuel pools. Both units were then placed in safe storage pending the commencement of site decommissioning and dismantlement. In 2010, the U.S. Nuclear Regulatory Commission (NRC) operating license was transferred from Exelon Generation Company (Exelon) to ZionSolutions, LLC (ZS) to allow the physical decommissioning process that began in 2010 and is expected to be completed within 10 years. The end-state and primary decommissioning objective at ZNPS is the transfer of all spent nuclear fuel to the independent spent fuel storage installation and to reduce residual radioactivity levels below the criteria specified in 10 CFR 20.1402, permitting release of the site for unrestricted use. Upon successful completion of the decommissioning activities, control and responsibility for the site will be transferred back to Exelon and the independent spent fuel storage installation maintained under Exelons Part 50 license (EC 2015).
ZSs decommissioning commitments were that, all above-grade structures, with minor exceptions, would be demolished. Structures below the 588-foot elevation (referenced from mean sea level),
consisting of primarily exterior subgrade walls and floors, would remain. These basement structures would be backfilled as part of the final site restoration. In order to demonstrate compliance with the release criteria in 10 CFR 20.1402, ZS would implement a final status survey (FSS) of remaining basement structures along with associated embedded piping and penetrations, buried piping, and surface and subsurface soil. FSS methodologies are outlined in Chapter 5 of ZSs license termination plan (LTP) (ZS 2018a). NRC issued license amendments 178 and 191 to approve ZSs LTP in September of 2018 (NRC 2018a). The primary FSS method for basement structure survey units (SUs) was in situ gamma measurements using a portable, high-resolution gamma spectrometer. FSS methods were based on methods outlined in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (NRC 2000).
Zion Containment and Auxiliary Penetrations 2
5271-SR-04-0 NRC requested that the Oak Ridge Institute for Science and Education (ORISE) perform confirmatory survey activities of select remaining penetrations and embedded piping in the Containment and Auxiliary Buildings at ZNPS. This report summarizes the confirmatory survey activities and results for these areas.
- 2. SITE DESCRIPTION ZNPS is located in Lake County, Illinois, on the easternmost portion of the city of Zion. It is approximately 64 kilometers (40 miles) north of Chicago, Illinois, and 68 kilometers (42 miles) south of Milwaukee, Wisconsin. The owner-controlled site is composed of approximately 134 hectares (331 acres) and is situated between the northern and southern parts of Illinois Beach State Park on the western shore of Lake Michigan (EC 2015 and ZS 2018a). Figure 2.1 provides an overview of ZNPS. The site and its surrounding environs is relatively flat, with the elevation of the developed portion of the site at approximately 591 feet above mean sea level. For reference, the elevation of Lake Michigan, which bounds the site on the east, is approximately 577.4 feet at low water level (ZS 2018a).
Figure 2.1. ZNPS Overview (adapted from ZS 2018a)
Zion Containment and Auxiliary Penetrations 3
5271-SR-04-0 2.1 UNIT 1 AND 2 CONTAINMENT BUILDING PENETRATIONS AND EMBEDDED PIPING The Containment Buildings housed the reactor pressure vessels and consist of a steel liner with interior and exterior concrete several feet thick. In both Containment Building basements, all concrete from the interior of the steel liner from the 565-foot to the 588-foot elevation was removed. The Containment Buildings contained multiple penetrations ranging from 6 to 50 inches in diameter and 4 to 52 feet in length (ZS 2018b). The only embedded piping remaining in each Containment Building is the 1.5-inch diameter in-core sump drain pipe.
2.2 AUXILIARY BUILDING PENETRATIONS The Auxiliary Building housed various support systems for both reactors, such as residual heat removal and reactor letdown systems. The Auxiliary Building basement consists of wall and floor structures below the 588-foot elevation. Auxiliary Building structures above the 588-foot elevation were demolished, leaving the basement open to the environment at the time of the confirmatory activities. The Auxiliary Building contained multiple penetrations ranging from 2.5 to 36 inches in diameter all with a length of 3 feet (ZS 2018b).
Figure 2.2 displays the licensed area with the Containment and Auxiliary Buildings indicated.
Figure 2.2. ZNPS Containment and Auxiliary Buildings (Google Earth)
Zion Containment and Auxiliary Penetrations 4
5271-SR-04-0
- 3. DATA QUALITY OBJECTIVES The data quality objectives (DQOs) described herein are consistent with the Guidance on Systematic Planning Using the Data Quality Objectives Process (EPA 2006) and provide a formalized method for planning radiation surveys, improving survey efficiency and effectiveness, and ensuring that the type, quality, and quantity of data collected are adequate for the intended decision applications.
The seven steps of the DQO process are as follows:
- 1. State the problem
- 2. Identify the decision/objective
- 3. Identify inputs to the decision/objective
- 4. Define the study boundaries
- 5. Develop a decision rule
- 6. Specify limits on decision errors
- 7. Optimize the design for obtaining data 3.1 STATE THE PROBLEM The first step in the DQO process defined the problem that necessitated the study, identified the planning team, and examined the project budget and schedule. Prior to the confirmatory site visit, ZS was in the process of dismantling remaining structures and remediating remaining land areas. As part of this process, ZS conducted an FSS to demonstrate compliance with NRCs license termination criteria specified in 10 CFR 20.1402. To this end, NRC staff requested that ORISE perform confirmatory surveys of the penetrations and embedded piping in the Containment Buildings and Auxiliary Building to provide independent confirmatory data for NRCs consideration in their evaluation of the FSS. The problem statement was formulated as follows:
Confirmatory surveys are necessary to generate independent radiological data for NRCs consideration in the evaluation of the FSS design, implementation, and results for demonstrating compliance with the release criteria.
Zion Containment and Auxiliary Penetrations 5
5271-SR-04-0 3.2 IDENTIFY THE DECISION/OBJECTIVE The second step in the DQO process identified the principal study questions (PSQs) and alternate actions (AAs), developed a decision statement (DS), and organized multiple decisions, as appropriate. This was done by specifying AAs that could result from a yes response to the PSQ and combining the PSQ and AAs into a DS. Table 3.1 presents the confirmatory survey decision process.
Table 3.1. FSS Confirmatory Survey Decision Process Principal Study Question Alternate Actions Are the FSS measurements of penetrations and embedded piping equivalent to the ORISE independent confirmatory measurements?
Yes:
Confirmatory survey results indicate that FSS measurements of penetrations and embedded piping are equivalent to the ORISE measurements; therefore, compile confirmatory survey data and present the results to NRC.
No:
Confirmatory survey results indicate that there is a positive statistical bias in the ORISE confirmatory measurements relative to the FSS measurements; therefore, summarize the discrepancies and provide technical comments to NRC.
Decision Statement The FSS results for penetrations and embedded piping are/are not equivalent to the ORISE confirmatory survey measurements.
3.3 IDENTIFY INPUTS TO THE DECISION/OBJECTIVE The third step in the DQO process identified both the information needed and the sources of this information, determined the basis for action levels, and identified sampling and analytical methods that will meet data requirements. For this effort, information inputs include the following:
- FSS data for Unit 1 Containment, Unit 2 Containment, and the Auxiliary Building penetrations
- ZS derived concentration guideline levels (DCGLs), discussed in subsection 3.3.1
- ORISE confirmatory survey results, including surface radiation scans and direct surface activity measurements
Zion Containment and Auxiliary Penetrations 6
5271-SR-04-0 3.3.1 Radionuclides of Concern and Release Guidelines The primary radionuclides of concern (ROCs) identified for the ZNPS are beta-gamma emitters fission and activation productsresulting from reactor operations. At ZNPS, there are four distinct source terms: basement structures, soils, buried piping, and groundwater. Furthermore, basement structures are composed of four structural source terms: surfaces, embedded piping, penetrations, and fill. ZS has developed site-specific DCGLs that correspond to a residual radioactive contamination level, above background, which could result in a total effective dose equivalent (TEDE) of 25 millirem per year (mrem/yr) to an average member of the critical group. These DCGLsdefined in ZSs LTP as Base Case DCGLs (DCGLBCs)are radionuclide-specific and independently correspond to a TEDE of 25 mrem/yr for each source term. In order to ensure that the total dose from all source terms is less than the NRC-approved release criteria, the DCGLBCs are further reduced to Operational DCGLs (DCGLOps). The DCGLOps are scaled to an expected dose from prior investigations and are used for remediation and FSS design purposes. The initial suite of ROCs present at ZNPS was reduced based on an insignificant dose contribution from a number of radionuclides. The DCGLBCs and DCGLOps, accounting for insignificant dose contributors, for embedded piping and penetrationsexcluding fill material, are presented in Tables 3.2 and 3.3, respectively.
Table 3.2. ZS Embedded Piping DCGLsa ROC Auxiliary Bldg.
Basement Embedded Floor Drains Turbine Bldg.
Basement Embedded Floor Drains Unit 1 Containment In-Core Sump Embedded Drain Pipe Unit 2 Containment In-Core Sump Embedded Drain Pipe Unit 1 &
Unit 2 Steam Tunnel Embedded Floor Drains Unit 1 Tendon Tunnel Embedded Floor Drains Unit 2 Tendon Tunnel Embedded Floor Drains Base Case DCGLs (pCi/m2)
H-3 N/A N/A 8.28E+09 N/A 1.61E+10 Co-60 7.33E+09 6.31E+09 5.47E+09 4.07E+10 1.06E+10 Ni-63 2.78E+11 1.96E+11 1.40E+11 1.26E+12 2.72E+11 Cs-134 5.10E+09 1.43E+09 1.05E+09 9.22E+09 2.04E+09 Cs-137 2.68E+09 1.89E+09 1.37E+09 1.22E+10 2.67E+09 Sr-90 2.41E+08 6.94E+07 4.98E+07 4.48E+08 9.70E+07 Eu-152 N/A N/A 1.28E+10 N/A 2.48E+10 Eu-154 N/A N/A 1.11E+10 N/A 2.16E+10 Operational DCGLs (pCi/m2)
H-3 N/A N/A 6.62E+08 6.62E+08 N/A 3.22E+08 3.22E+08 Co-60 7.33E+09 2.52E+08 4.38E+08 4.38E+08 1.63E+09 2.12E+08 2.12E+08
Zion Containment and Auxiliary Penetrations 7
5271-SR-04-0 Table 3.2. ZS Embedded Piping DCGLsa ROC Auxiliary Bldg.
Basement Embedded Floor Drains Turbine Bldg.
Basement Embedded Floor Drains Unit 1 Containment In-Core Sump Embedded Drain Pipe Unit 2 Containment In-Core Sump Embedded Drain Pipe Unit 1 &
Unit 2 Steam Tunnel Embedded Floor Drains Unit 1 Tendon Tunnel Embedded Floor Drains Unit 2 Tendon Tunnel Embedded Floor Drains Cs-134 5.10E+09 5.72E+07 8.40E+07 8.40E+07 3.69E+08 4.08E+07 4.08E+07 Cs-137 2.68E+09 7.56E+07 1.10E+08 1.10E+08 4.88E+08 5.34E+07 5.34E+07 Ni-63 2.78E+11 7.84E+09 1.12E+10 1.12E+10 5.04E+10 5.44E+09 5.44E+09 Sr-90 2.41E+08 2.78E+06 3.98E+06 3.98E+06 1.79E+07 1.94E+06 1.94E+06 Eu-152 N/A N/A 1.02E+09 1.02E+09 N/A 4.96E+08 4.96E+08 Eu-154 N/A N/A 8.88E+08 8.88E+08 N/A 4.32E+08 4.32E+08 aRecreated from ZS 2018a.
pCi/m2 = picocuries per square meter ROC = radionuclide of concern Table 3.3. ZS Penetration DCGLsa ROC Auxiliary Building Unit 1 & Unit 2 Containment SFP/Transfer Canal Turbine Building Crib House/
Forebayb WWTFb Base Case DCGLs (pCi/m2)
H-3 3.99E+09 3.42E+09 4.84E+16 3.23E+09 N/A N/A Co-60 8.82E+07 2.26E+09 4.45E+08 1.76E+09 N/A N/A Cs-134 3.28E+08 4.32E+08 7.48E+08 4.00E+08 N/A N/A Cs-137 6.17E+08 5.66E+08 1.46E+09 5.29E+08 N/A N/A Ni-63 6.79E+10 5.78E+10 1.86E+14 5.48E+10 N/A N/A Sr-90 2.41E+07 2.06E+07 9.26E+10 1.94E+07 N/A N/A Eu-152 3.29E+08 5.26E+09 9.44E+08 4.06E+09 N/A N/A Eu-154 2.33E+08 4.58E+09 8.53E+08 3.58E+09 N/A N/A Operational DCGLs (pCi/m2)
H-3 3.14E+08 2.33E+08 1.13E+16 2.58E+08 N/A N/A Co-60 6.95E+06 1.54E+08 1.04E+08 1.41E+08 N/A N/A Cs-134 2.58E+07 2.94E+07 1.74E+08 3.20E+07 N/A N/A Cs-137 4.86E+07 3.85E+07 3.40E+08 4.23E+07 N/A N/A Ni-63 5.35E+09 3.93E+09 4.33E+13 4.38E+09 N/A N/A Sr-90 1.90E+06 1.40E+06 2.16E+10 1.55E+06 N/A N/A Eu-152 2.59E+07 3.58E+08 2.20E+08 3.25E+08 N/A N/A Eu-154 1.84E+07 3.11E+08 1.99E+08 2.86E+08 N/A N/A aRecreated from ZS 2018a.
bThe Base Case and Operational DCGLs are not applicable because of the small surface area of penetrations present.
The corresponding DCGLs for basement surfaces will apply.
pCi/m2 = picocuries per square meter ROC = radionuclide of concern WWTF = Waste Water Treatment Facility
Zion Containment and Auxiliary Penetrations 8
5271-SR-04-0 Because each of the individual DCGLBCs represents a separate radiological dose, the sum-of-fractions (SOF) approach must be used to evaluate the total dose from the SU and demonstrate compliance with the dose limit. SOF calculations were performed as follows:
=
Cmean,j DCGLBC,j
=1
+,,
,x Where:
Cmean,j is the mean concentration of ROC j CElv,j is an elevated area of ROC j DCGLBC,j is the Base Case DCGL for ROC j AF,j is the area factor for ROC j It is important to note that AFsas described by MARSSIMare only applicable to soils.
However, the DCGLBCs for basement structures are scaled by area to account for elevated radioactivity. In this case, the AF in the equation above is equal to the SU surface area divided by the surface area of the elevated hot spot (HS) (AF = SUSA/HSSA). For soils, the quantity (DCGLBC,j x AFj) is referred to as the elevated measurement comparison, denoted by DCGLEMC.
Note that gross concentrations are considered here for conservatism.
3.4 DEFINE THE STUDY BOUNDARIES The fourth step in the DQO process defined target populations and spatial boundaries, determined the timeframe for collecting data and making decisions, addressed practical constraints, and determined the smallest subpopulations, area, volume, and time for which separate decisions must be made. Confirmatory surveys were performed on select penetrations and embedded piping in the Containment and Auxiliary buildings during the period of June 4-7, 2018. Penetrations selected for confirmatory survey were based on the highest FSS SOF results of penetrations that will remain.
Table 3.4 lists SUs that were initially selected for confirmatory survey. Each SU listed in Table 3.4 corresponds to the smallest subpopulation where decisions are made.
Zion Containment and Auxiliary Penetrations 9
5271-SR-04-0 Table 3.4. Penetrations Selected for Confirmatory Survey Unit 1 Containment Unit 2 Containment Auxiliary P035 Recirculating Sump Suction P235 Recirculating Sump Suction A011 Waste Disposal P036 Cavity Flood Sump Suction P236 Cavity Flood Sump Suction A023 Waste Disposal P037 Cavity Flood Sump Suction P237 Cavity Flood Sump Suction P123 Recirculating Sump Suction P323 Recirculating Sump Suction P124 Recirculating Sump Suction P324 Recirculating Sump Suction P125a In-Core Sump Discharge Pipe P325a,b In-Core Sump Discharge Pipe aClassified as embedded piping and, thus, DCGLs in Table 3.2 apply.
bThis piping was removed during remediation and was not available for confirmatory survey.
3.5 DEVELOP A DECISION RULE The fifth step in the DQO process specified appropriate population parameters (e.g., mean, median), confirmed action levels were above detection limits, and developed an ifthen decision rule statement. Decision rules for this survey were based on independent scan surveys and randomly and judgmentally selected surface activity measurements to determine whether there is a potential low relative statistical bias between the FSS and confirmatory data sets. FSS measurements consisted of surface activity measurements collected at 1-foot intervals throughout the length of the penetration. The FSS measurements were performed using sodium iodide (NaI) scintillation detectors calibrated to Cs-137 gamma rays1. Radionuclide-specific surface activity valuesin units of picocuries per square meter (pCi/m2)were calculated using the gross surface activity and the expected ROC activity contributions from the LTP.
For the Containment Building penetrations, ORISE collected co-located surface activity measurements to assess whether the confirmatory measurements and FSS measurements were from the same population distribution. FSS measurements in both of the Containment Buildings penetrations were performed using a 3-inch by 3-inch NaI detector, whereas the confirmatory measurements were collected with a 2-inch by 2-inch NaI detector. FSS measurements were reported as a gross value, uncorrected for background. The difference in detector volumes precluded a direct comparison of the gross response, as the relative response between the two detectors is dependent on the energy of the measured photons. Additionally, the FSS measurements were converted to units of total activity concentration and reported as a gross value, uncorrected for background. This prevented a direct comparison of the measurements reported in units of pCi/m2.
1 The gamma rays are from the Cs-137 daughter, Ba-137m
Zion Containment and Auxiliary Penetrations 10 5271-SR-04-0 Therefore, the data sets were normalized, pooled and rank-transformed prior to analysis. Thus, the parameter of interest is the mean difference of ranks between the confirmatory measurements and the FSS data sets.
Figure 3.1 presents an example FSS surface activity profile along the length of penetration P324 in the Unit 2 Containment Building. The peaks indicate the presence of relatively localized deposits of residual contamination. Additionally, judgmental confirmatory measurements were collected at these locationsif not randomly selectedfor comparison directly to the DCGLBC.
Figure 3.1. FSS Surface Activity Length Profile for Penetration P324 in the Unit 2 Containment Building FSS data assessment was performed by converting gross instrument counts to disintegrations per minute (dpm) using the efficiency factor determined with the Cs-137 calibration standard. The total dpm value was then divided among other gamma-emitting ROCs based on the abundance fractions determined from characterization. The divided activity values were then converted into units of pCi/m2 based on the surface area of a 1-foot length of penetration/pipe. This process is analogous to the gross activity DCGL (DCGLGROSS), which is often implemented in typical MARSSIM-based structural FSS, except in reverse. Typically, when developing a DCGLGROSS, individual DCGLs are weighted by the ROC abundance. Individual measurements then can be compared to the DCGLGROSS by an efficiency factor that accounts for the relative abundances. For confirmatory survey data evaluation, individual results were compared to the gamma-emitting ROC with the lowest DCGLBC.
Zion Containment and Auxiliary Penetrations 11 5271-SR-04-0 Based on the previous discussion, the decision rule is stated as follows:
If the confirmatory survey data and FSS data are in agreement and all measurements are below the lowest DCGLBC for gamma-emitters, then conclude that the FSS data are acceptable for demonstrating compliance with the release criterion; otherwise, perform further evaluation(s) and provide technical comments/recommendations to the NRC for their evaluation and decision making.
3.6 SPECIFY LIMITS ON DECISION ERRORS The sixth step in the DQO process examined the consequences of making an incorrect decision and established bounds on decision errors. Decision errors were controlled during the survey design, on-site field investigations, and during the data assessment. There were two orders of control, each discussed in the following subsections.
3.6.1 Hypothesis Testing The first order of control was related to the evaluation of the FSS data relative to the confirmatory survey data. Hypothesis testing adopts a scientific approach where the survey data were used to select between the baseline condition (the null hypothesis, H0) and an alternative condition (the alternative hypothesis, HA). The null hypothesis, or the assumed base condition, is normally stated based on which base condition carries the greatest risk, such as releasing a contaminated area or alternatively expending budgeted resources on investigations of likely clean areas. The confirmatory survey was the last step in the site survey and investigation process, as such the procedures and processes used to generate the FSS data received some level of review both by the licensee and the NRC. Therefore, the null and alternative hypotheses were as follows:
H0: The mean confirmatory measurement population ranks (RCU) were less than or equal to the FSS mean population ranks (RFSS). Mathematically, the null hypothesis was stated as: RCU - RFSS 0.
HA: The mean confirmatory measurement population ranks were greater than the FSS mean population ranks. Mathematically, the alternative hypothesis was stated as: RCU - RFSS > 0.
Zion Containment and Auxiliary Penetrations 12 5271-SR-04-0 For the hypothesis testing, two types of decision errors were considered: Type I (typically designated as alpha or ) and Type II (typically designated as beta or ). A Type I error occurs when the null hypothesis is rejected when it should not be rejected, also known as a false positive, and reflects the confidence level in the decision. A Type II error is incorrectly failing to reject the null hypothesis when the alternative hypothesis is true. This is also known as a false negative.
Decision errors were controlled both during field activities and during data quality assessment and were based on two orders of control. The Type I error rate was set to =0.05, that is, there is a 5%
chance of incorrectly rejecting the null hypothesis. The power of the statistical test, or the probability of the test to correctly reject the null hypothesis when it is false, is denoted as the quantity (1 - ). Typically, a prospective power is defined by selecting a Type II error rate that is acceptable while not requiring an overly burdensome sample size. The prospective Type II error rate was no greater than 0.1, that is, there is no greater than a 10% chance of concluding the confirmatory population mean is less than the FSS population mean when it is actually greater. The actual Type II error rate, and subsequent power, achieved is dependent on the number of samples collected and the concentration variability in the sample set.
3.6.2 Field and Analytical MDCs The second order of control was to optimize minimum detectable concentrations (MDCs) with respect to ORISE sample count times for both field and laboratory measurements. Measurement MDCs were, at a minimum, equal to 50% of the guidelines presented in Tables 3.2 and 3.3.
3.7 OPTIMIZE THE DESIGN FOR OBTAINING DATA The seventh step in the DQO process was used to review DQO outputs, develop data collection design alternatives, formulate mathematical expressions for each design, select the sample size to satisfy DQOs, decide on the most resource-effective design of agreed upon alternatives, and document requisite details. Specific survey procedures are presented in Section 4.
- 4. PROCEDURES The ORISE survey team conducted independent confirmatory survey activities, including gamma surface scans, direct gamma measurements, and miscellaneous sampling activities within the
Zion Containment and Auxiliary Penetrations 13 5271-SR-04-0 accessible survey areas specifically requested by NRC. Survey activities were conducted in accordance with the Oak Ridge Associated Universities (ORAU) Radiological and Environmental Survey Procedures Manual and the ORAU Environmental Services and Radiation Training Quality Program Manual (ORAU 2016a and ORAU 2018).
4.1 REFERENCE SYSTEM Penetrations were segmented into 1-foot sections corresponding to measurements performed by ZS.
ORISE referenced confirmatory measurements in terms of the number of 1-foot segments from the origin. For the Containment Buildings, the origin of penetrations was the termination of the specific penetration on the Auxiliary Building side. For example, Location 0 corresponds to the beginning of the first 1-foot penetration segment from the Auxiliary Building moving toward the Containment Buildings. The embedded piping and penetrations measured in the Unit 1 Containment and Auxiliary Buildings, respectively, were referenced in a similar manner. For these two areas, the detector was fully inserted into the penetration/embedded piping from the access point. Select 1-foot segments were measured as the detector was withdrawn.
4.2 SURFACE SCANS Cesium iodide (CsI) and NaI pipe detectors were used to evaluate direct gamma radiation levels on interior penetration surfaces. All detectors were coupled to Ludlum Model 2221 ratemeter-scalers with audible indicators. Locations of elevated response that were audibly distinguishable from background levels, suggesting the presence of residual contamination, were further investigated with a follow-up, static gamma measurement.
4.3 SURFACE ACTIVITY MEASUREMENTS Surface activity measurements were collected from both randomly and judgmentally selected locations. Visual Sample Plan (VSP), Version 7.9, was used to determine the number of random co-located measurements to meet the DQOs specified in the previous section. Figure 4.1 provides the VSP inputs to determine the number of measurements. As indicated in Figure 4.1, 28 measurements were required; thus, 28 1-foot penetration segments were randomly selected for measurement. For the Unit 1 Containment in-core sump discharge embedded piping, the detector
Zion Containment and Auxiliary Penetrations 14 5271-SR-04-0 was fully inserted into the piping from access points on the 565-foot Elevation and Under-vessel Area. Every other 1-foot pipe segment was measured as the detector was withdrawn, for a total of 13 measurements. Because of the small relative length (approximately 3 feet) of the penetrations in the Auxiliary Building, the entire portion of the penetrations was measured in 1-foot segments, for a total of three measurements in each penetration.
Figure 4.1. Sample Size Determination Using VSP Static surface activity measurements were collected using either a Ludlum Model 44-157 NaI pipe detector or a Ludlum Model 44-159-1 CsI detector, depending on the length of the penetration. All detectors were coupled to Ludlum Model 2221 ratemeter-scalers. The count time for each static measurement was 1 minute. Detectors were calibrated to a Cs-137 standard in a manner that accounts for varying pipe diameter, and measurements were collected with the detector on the bottom on the penetration/pipe. The choice of Cs-137 as a calibration standard is conservative, because of the low efficiency of the scintillation detector relative to other gamma-emitting ROCs.
The calibration methodology is discussed further in Appendix C.
4.4 MISCELLANEOUS SAMPLING A miscellaneous sample of residual material was collected from penetration P035 in Unit 1 Containment. The sample was collected by wiping a cloth over the bottom portion of the penetration interior totaling approximately 0.25 m2.
Zion Containment and Auxiliary Penetrations 15 5271-SR-04-0
- 5. SAMPLE ANALYSIS AND DATA INTERPRETATION Data and the miscellaneous sample collected on site were transferred to the ORISE facility for analysis and interpretation. Sample custody was transferred to the Radiological and Environmental Analytical Laboratory in Oak Ridge, Tennessee. Sample analyses were performed in accordance with the ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2017). The miscellaneous sample was analyzed by high-resolution gamma spectrometry for gamma emitting Cs-134/137, Co-60, and Eu-152/154 and by alpha spectrometry for Am-241 after chemical separation. Laboratory results were reported in units of pCi/sample. Direct surface activity measurements were reported in units of pCi/m2. For consistency with the FSS measurements, surface activity measurements were not corrected for background contributions.
Both data sets were normalized based on the median and interquartile range (IQR) according to the following formula:
,=
1/2
Where:
Xi = the ith measurement in each data set
µ1/2 = the sample median IQR = interquartile range for the data set, defined as the difference between the 75th and 25th quartile After each data set was normalized, the results were pooled and ranked in ascending order. The mean difference between confirmatory and FSS sample ranks was evaluated using the two-sample Students t-test. Results for the t-test were generated using ProUCL, version 5.1.
Zion Containment and Auxiliary Penetrations 16 5271-SR-04-0
- 6. FINDINGS AND RESULTS The results of the confirmatory survey are discussed in the following subsections.
6.1 UNIT 1 CONTAINMENT 6.1.1 Surface Scans Overall surface scans in the Unit 1 Containment penetrations ranged from approximately 2,500 counts per minute (cpm) to 260,000 cpm, the highest of which was observed in P123, a reactor recirculating sump suction penetration. Scan ranges by penetration are summarized in Table 6.1.
Table 6.1. Summary of Unit 1 Penetration Scan Range Penetration Scan Range (cpm)a P035 3,000 to 25,000 P036 2,500 to 20,000 P037 2,500 to 25,000 P123 3,900 to 260,000 P124 2,700 to 95,000 aLudlum Detector Model 44-157 used 6.1.2 Surface Activity Measurements Individual surface activity measurements are presented in Table B.1 in Appendix B. Table 6.2 presents a summary of the confirmatory measurements collected in Unit 1 Containment penetrations.
Table 6.2. Summary of Confirmatory Measurements in Unit 1 Penetrationsa Penetration Parameter (pCi/m2)
Average Median SD Min Max P035 9.70E+05 7.84E+05 8.08E+05 6.79E+05 5.05E+06 P036 9.08E+05 7.77E+05 7.38E+05 4.12E+05 4.64E+06 P037 9.47E+05 7.93E+05 8.34E+05 6.38E+05 5.17E+06 P123 2.34E+07 1.07E+07 2.52E+07 1.29E+06 7.34E+07 P124 8.11E+06 7.71E+06 6.67E+06 9.63E+05 2.28E+07 aLudlum Detector Model 44-157 used
Zion Containment and Auxiliary Penetrations 17 5271-SR-04-0 The maximum surface activity measurement was collected from penetration P123 at 7.34E+07 pCi/m2, which is a small fraction of the Cs-134 DCGLBC at 17%
(7.34E+07 pCi/m2 /4.32E+08 pCi/m2). Cs-134 has the lowest DCGLBC of all the gamma-emitters listed in Table 3.3; therefore, a change in the assigned gamma-emitting ROC mix would not result in an exceedance of the respective DCGLBC.
Individual surface activity measurements for the Unit 1 in-core sump discharge embedded piping are presented in Table B.2. Results were compared directly to the DCGLBC for Cs-134. The maximum measurement collected was 2.77E+07 pCi/m2, which is approximately 3% of the DCGLBC (2.77E+07 pCi/m2 /1.05E+09 pCi/m2).
6.1.3 Comparison of FSS and Confirmatory Data Sets Raw detector responses (in units of cpm) for the paired measurements were plotted to examine the NaI response profile of each penetration. The plots for Unit 1 Containment penetrations are presented in Figure A.1 in Appendix A. Review of Figure A.1 indicates that the measurement pairs trend similarly between the FSS and confirmatory measurements throughout the length of the penetration (i.e., when the ORISE measurement indicates elevated activity, the FSS measurement is elevated in the same manner relative to other locations in the penetration).
Table 6.3 presents a summary of the Students t-test performed on measurements collected in Unit 1 Containment penetrations. There was not sufficient evidence to reject the null hypothesis for any of the penetrations investigated. Individual measurements used for the Students t-test are presented in Table B.3.
Table 6.3. Students t-Test Summary for Unit 1 Penetrations Penetration t
T p-val Result P035 0.390 1.674 0.35 p-val > 0.05: Fail to reject the null P036
-0.718 1.674 0.76 p-val > 0.05: Fail to reject the null P037 0.016 1.674 0.49 p-val > 0.05: Fail to reject the null P123
-1.218 1.674 0.89 p-val > 0.05: Fail to reject the null P124
-1.218 1.674 0.89 p-val > 0.05: Fail to reject the null t = t-test statistic T = critical value p-val = p-value; probability of t T
Zion Containment and Auxiliary Penetrations 18 5271-SR-04-0 6.1.4 ROC Activity in the Swipe Sample The swipe sample collected from penetration P035 in Unit 1 Containment was initially analyzed by gamma spectrometry, and the analysis revealed the presence of Am-241. Subsequent analysis via alpha spectrometry confirmed the presence of Am-241. Cm-244 also was noted as present in the sample (Cm follows the Am chemistry during the laboratory sample preparation process); however, since Cm was not anticipated, the sample was not processed to account for the slight difference in chemistry compared to Am. Therefore, the Cm-244 activity was not officially reported by the laboratory; although, the laboratory noted that the Cm-244 activity is expected to be approximately one-third of the Am-241 activity. The results for the miscellaneous sample swipe are presented in Table 6.4.
Table 6.4. ROC Activity in Miscellaneous Sample 5271M0038 Swipea ROC Concentration (pCi/Sample)b Am-241 154 +/- 24 Co-60 17,890 +/- 970 Cs-134b 20 +/- 52 Cs-137 3,870 +/- 270 Eu-152 736 +/- 83 Eu-154c 190 +/- 190 Cm-244d NR aAn area totaling approximately 0.25 m2 was wiped.
bUncertainties represent the total propagated uncertainty reported at the 95%
confidence level.
cROC activity was not present above the analytical MDC.
dCm-244 was identified, but value was not officially reported by the laboratory.
NR = not reported 6.2 UNIT 2 CONTAINMENT 6.2.1 Surface Scans Overall surface scans in Unit 2 Containment penetrations ranged from approximately 2,500 cpm to 15,000 cpm, the highest of which was observed in P324, a reactor recirculating sump suction penetration. Scan ranges by penetration are summarized in Table 6.5.
Zion Containment and Auxiliary Penetrations 19 5271-SR-04-0 Table 6.5. Summary of Unit 2 Penetration Scan Range Penetration Scan Range (cpm)a P235 2,500 to 10,000 P236 2,500 to 9,000 P237 2,500 to 8,000 P323 3,000 to 10,000 P324 3,000 to 15,000 aLudlum detector Model 44-157 used 6.2.2 Surface Activity Measurements Individual surface activity measurements are presented in Table B.4. Table 6.6 presents a summary of the confirmatory measurements collected in Unit 2 Containment penetrations.
Table 6.6. Summary of Confirmatory Measurements in Unit 2 Penetrationsa Penetration Parameter (pCi/m2)
Average Median SD Min Max P235 7.67E+05 7.03E+05 2.68E+05 6.26E+05 2.10E+06 P236 7.41E+05 6.88E+05 2.46E+05 6.06E+05 1.96E+06 P237 7.22E+05 6.55E+05 2.26E+05 5.89E+05 1.83E+06 P323 1.14E+06 1.02E+06 4.34E+05 7.53E+05 2.53E+06 P324 1.01E+06 8.85E+05 3.00E+05 7.10E+05 1.99E+06 aLudlum detector Model 44-157 used The maximum surface activity measurement was a judgmental (Table B.4) measurement collected from penetration P324 at 3.26E+06 pCi/m2, which is less than 1% of the Cs-134 DCGLBC (3.26E+06 pCi/m2 /4.32E+08 pCi/m2). Cs-134 has the lowest DCGLBC of all the gamma-emitters listed in Table 3.4; therefore, a change in the assigned gamma-emitting ROC mix would not result in an exceedance of their respective DCGLBC.
6.2.3 Comparison of FSS and Confirmatory Data Sets As with the penetrations in Unit 1 Containment, the Unit 2 Containment raw detector responses (in units of cpm) for the paired measurements were plotted to examine the NaI response profile of each penetration. These plots for the Unit 2 Containment penetrations are presented in Figure A.2.
Review of Figure A.2 indicates that the measurement pairs trend similarly between the FSS and confirmatory measurements throughout the length of the penetration, with the exception of P323.
The confirmatory measurement data set is missing a peak at Location 1 that is present in the FSS
Zion Containment and Auxiliary Penetrations 20 5271-SR-04-0 data set. The survey team noted what appeared to be loose concrete rubble in several of the penetrations. A possible explanation for the missing peak in the P323 data set is that loose concrete rubble containing contamination inside penetration P323 was removed prior to the confirmatory survey.
Table 6.7 presents a summary of the Students t-test performed on measurements collected in Unit 2 Containment penetrations. There was not sufficient evidence to reject the null hypothesis for any of the penetrations investigated. Individual measurement pairs used for the Students t-test test are presented in Table B.5.
Table 6.7. Students t-Test Summary for Unit 2 Penetrations Penetration t
T p-val Result P235
-0.751 1.674 0.772 p-val > 0.05: Fail to reject the null P236 0.049 1.674 0.481 p-val > 0.05: Fail to reject the null P237
-0.57 1.674 0.714 p-val > 0.05: Fail to reject the null P323
-0.8 1.674 0.786 p-val > 0.05: Fail to reject the null P324
-0.244 1.674 0.596 p-val > 0.05: Fail to reject the null t = t-test statistic T = critical value p-val = p-value; probability of t T 6.3 AUXILIARY BUILDING Surface scans were not performed in the investigated Auxiliary Building penetrations A011 and A023 because the static measurements covered the entire penetration. Table 6.8 presents the Auxiliary Building penetration measurements. Because of the small sample size, the confirmatory measurements were not compared to the FSS measurements, but, rather, were compared directly to the DCGLBC. The maximum measurement was collected from penetration A011 and was approximately 4% of the Cs-137 DCGLBC (2.57E+07 pCi/m2 /6.17E+08 pCi/m2). Assuming that the predominant gamma-emitting ROC is Co-60, which has the lowest DCGLBC of gamma-emitting ROCs in Table 3.3 instead of Cs-137, the max result is approximately 30% of the DCGLBC (2.57E+07 pCi/m2 /8.82E+07 pCi/m2).
Zion Containment and Auxiliary Penetrations 21 5271-SR-04-0 Table 6.8. Confirmatory Measurements in the Auxiliary Building A011a A023b Locationc Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Location Gross Count (cpm)
Gross Surface Activity (pCi/m2) 0 6,957 2.09E+07 0
20,421 5.17E+06 1
8,546 2.57E+07 1
36,759 9.30E+06 2
6,041 1.81E+07 2
34,129 8.63E+06 aLudlum detector Model 44-159-1 used bLudlum detector Model 44-157 used cLocation refers to the 1-foot pipe segment referenced from the origin, which was the furthest point in the piping accessed from the Auxiliary Building.
- 7.
SUMMARY
AND CONCLUSIONS At NRCs request, ORISE conducted confirmatory survey activities at ZNPS during the period of June 4-7, 2018. The survey activities included gamma surface scans, direct gamma measurements, and miscellaneous sampling. None of the piping/penetration interior direct measurements exceeded the most restrictive DCGLBC in any of the areas investigated as part of the confirmatory survey. A cloth wipe of the penetration P035 interior identified the presence of Am-241, which was deselected from FSS analysis based on an insignificant dose contribution. The Am-241 activity on the wipe, which represents the removable ROC portion, was at least an order of magnitude less than the more predominant gamma-emitters, Cs-137 and Co-60.
For the paired measurements, there was not sufficient evidence to reject the null hypothesis for all investigated Unit 1 and Unit 2 containment penetrations, except for P323 in Unit 2 Containment.
Thus, since the sample ranks are not statistically different, it is concluded that the confirmatory and FSS measurements were drawn from the same population distribution. The difference in the NaI response profile for Location 1 in penetration P323 may be explained by loose debris containing contamination that was present inside of the penetration during FSS, but was not present during the confirmatory survey. However, additional evaluation is not recommended given the low magnitude of the confirmatory survey measurements relative to the DCGLBC.
The results of the confirmatory surveys conducted by ORISE did not identify issues that would preclude the FSS data from demonstrating compliance with the release criteria.
Zion Containment and Auxiliary Penetrations 22 5271-SR-04-0
- 8. REFERENCES EC 2015. The Future of Zion. Webpage: http://www.exeloncorp.com/locations/power-plants/zion-station. Exelon Corporation. Chicago, Illinois. Accessed June 30, 2015.
EPA 2006. Guidance on Systematic Planning Using the Data Quality Objectives Process. EPA QA/G-4.
U.S. Environmental Protection Agency. Washington, D.C. February.
NRC 2000. Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM). NUREG-1575; Revision 1. U.S. Nuclear Regulatory Commission. Washington, D.C. August.
NRC 2018. Letter from J.B. Hickman, USNRC, to J. Sauger, Energy Solutions, RE: Zion Nuclear Power Station, Units 1 and 2 - Issuance of Amendments 191 and 178 for the Licenses to Approve the License Termination Plan. September 28.
ORAU 2014. ORAU Radiation Protection Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. October.
ORAU 2016a. ORAU Radiological and Environmental Survey Procedures Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. November 10.
ORAU 2016b. ORAU Health and Safety Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. January.
ORAU 2017. ORAU Radiological and Environmental Analytical Laboratory Procedures Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. August 24.
ORAU 2018. ORAU Environmental Services and Radiation Training Quality Program Manual. Oak Ridge Associated Universities. Oak Ridge, Tennessee. July 20.
ZS 2018a. Zion Station Restoration Project License Termination Plan, Rev. 2. ZionSolutions, LLC. Chicago, Illinois. February 7.
ZS 2018b. Letter from D. Wojtkowiak, ZionSolutions to J. Hickman, NRC, RE: Summary of Embedded Piping and Penetrations for Unit 1 Containment, Unit 2 Containment, Auxiliary Building and the Turbine Building.
May 16.
Zion Containment and Auxiliary Penetrations 5271-SR-04-0 APPENDIX A: FIGURES
Zion Containment and Auxiliary Penetrations A-1 5271-SR-04-0 Figure A.1. Unit 1 Penetration NaI Response Profile
Zion Containment and Auxiliary Penetrations A-2 5271-SR-04-0 Figure A.2. Unit 2 Penetration NaI Response Profile
Zion Containment and Auxiliary Penetrations 5271-SR-04-0 APPENDIX B: DATA TABLES
Zion Containment and Auxiliary Penetrations B-1 5272-SR-04-0 Table B.1. Confirmatory Measurements in Unit 1 Penetrationsa P035 P036 P037 P123 P124 Loc.b Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2) 0 19,681 5.05E+06 0
18,090 4.64E+06 0
20,174 5.17E+06 1
261,720 6.71E+07 0
88,938 2.28E+07 1
4,277 1.10E+06 1
4,228 1.08E+06 1
4,121 1.06E+06 2
286,327 7.34E+07 1
56,290 1.44E+07 3
3,081 7.90E+05 2
3,179 8.15E+05 2
3,210 8.23E+05 5
221,934 5.69E+07 2
62,337 1.60E+07 4
3,198 8.20E+05 4
3,225 8.27E+05 4
3,151 8.08E+05 8
172,891 4.43E+07 3
61,751 1.58E+07 6
3,018 7.74E+05 5
3,202 8.21E+05 5
3,131 8.03E+05 9
180,581 4.63E+07 5
64,397 1.65E+07 7
3,071 7.88E+05 6
3,038 7.79E+05 6
3,144 8.06E+05 10 204,430 5.24E+07 7
51,462 1.32E+07 10 3,324 8.52E+05 8
3,233 8.29E+05 8
3,499 8.97E+05 12 231,571 5.94E+07 9
54,467 1.40E+07 11 3,245 8.32E+05 10 3,043 7.80E+05 9
3,271 8.39E+05 13 229,697 5.89E+07 10 58,168 1.49E+07 17 3,296 8.45E+05 11 3,193 8.19E+05 10 3,080 7.90E+05 14 191,506 4.91E+07 11 60,098 1.54E+07 19 2,994 7.68E+05 12 3,096 7.94E+05 11 3,039 7.79E+05 17 107,018 2.74E+07 15 50,267 1.29E+07 23 2,647 6.79E+05 14 3,024 7.75E+05 13 3,468 8.89E+05 18 141,016 3.62E+07 16 45,956 1.18E+07 25 2,697 6.92E+05 15 3,132 8.03E+05 14 3,108 7.97E+05 20 79,916 2.05E+07 17 40,794 1.05E+07 27 2,761 7.08E+05 20 3,068 7.87E+05 19 2,849 7.31E+05 21 62,427 1.60E+07 18 38,639 9.91E+06 28 2,682 6.88E+05 21 2,844 7.29E+05 20 2,608 6.69E+05 22 55,485 1.42E+07 19 32,940 8.45E+06 29 2,779 7.13E+05 24 2,807 7.20E+05 23 2,489 6.38E+05 23 27,689 7.10E+06 20 27,189 6.97E+06 30 2,819 7.23E+05 27 2,940 7.54E+05 26 2,610 6.69E+05 24 16,049 4.12E+06 21 23,047 5.91E+06 31 2,938 7.53E+05 28 2,955 7.58E+05 27 2,686 6.89E+05 28 9,760 2.50E+06 22 16,579 4.25E+06 33 2,795 7.17E+05 33 2,894 7.42E+05 32 2,765 7.09E+05 32 5,811 1.49E+06 23 11,543 2.96E+06 36 3,047 7.81E+05 35 2,880 7.39E+05 34 2,777 7.12E+05 34 8,604 2.21E+06 31 4,458 1.14E+06 37 3,030 7.77E+05 36 2,855 7.32E+05 35 2,854 7.32E+05 37 6,638 1.70E+06 36 4,073 1.04E+06 38 3,003 7.70E+05 39 2,814 7.22E+05 38 2,708 6.94E+05 39 5,224 1.34E+06 37 3,855 9.89E+05 39 3,042 7.80E+05 40 2,813 7.21E+05 39 2,707 6.94E+05 40 5,753 1.48E+06 39 4,144 1.06E+06 41 3,309 8.49E+05 42 2,880 7.39E+05 41 2,967 7.61E+05 42 6,051 1.55E+06 40 4,321 1.11E+06
Zion Containment and Auxiliary Penetrations B-2 5272-SR-04-0 Table B.1. (continued) Confirmatory Measurements in Unit 1 Penetrationsa P035 P036 P037 P123 P124 Loc.b Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2) 42 3,311 8.49E+05 43 2,927 7.51E+05 42 3,242 8.31E+05 43 8,102 2.08E+06 43 4,335 1.11E+06 44 4,588 1.18E+06 45 3,085 7.91E+05 44 3,324 8.52E+05 45 5,850 1.50E+06 46 3,980 1.02E+06 45 3,623 9.29E+05 46 3,157 8.10E+05 45 3,724 9.55E+05 46 5,019 1.29E+06 47 3,755 9.63E+05 46 3,726 9.56E+05 47 2,926 7.50E+05 47 3,802 9.75E+05 47 5,547 1.42E+06 48 3,837 9.84E+05 48 3,951 1.01E+06 48 1,607 4.12E+05 48 2,840 7.28E+05 48 7,598 1.95E+06 49 3,893 9.98E+05 13c 62,764 1.61E+07 aLudlum detector Model 44-157 used.
bLocation refers to the 1-foot pipe segment referenced from the origin, which is the termination of the penetration on the Auxiliary Building side.
cJudgmental measurement.
Loc. = Location
Zion Containment and Auxiliary Penetrations B-3 5272-SR-04-0 Table B.2. Unit 1 In-Core Sump Discharge Embedded Piping Confirmatory Measurementsa Locationb Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Measured from 565' Elevation 0
3228 1.04E+07 2
1098 3.55E+06 4
853 2.76E+06 6
808 2.61E+06 8
738 2.39E+06 10 612 1.98E+06 12 518 1.67E+06 14 677 2.19E+06 16 729 2.36E+06 18 1204 3.89E+06 20 1588 5.13E+06 Measured from UV Area 0
8558 2.77E+07 1
6255 2.02E+07 aLudlum detector Model 44-159-1 used bLocation refers to the 1-foot pipe segment referenced from the origin, which was the furthest point in the piping accessed from the specified location.
Zion Containment and Auxiliary Penetrations B-4 5272-SR-04-0 Table B.3. Measurement Data Used for Students t-Test in Unit 1 Containment P035 P036 P037 Loc.
FSS ORISE Loc.
FSS ORISE Loc.
FSS ORISE cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R 0
35,400 21.645 55 19,681 35.216 56 0
46,900 27.898 55 18,090 51.308 56 0
30,900 26.438 55 20,174 31.469 56 1
12,800 3.988 54 4,277 2.581 52 1
16,000 6.060 54 4,228 4.078 53 1
14,300 7.574 53 4,121 1.892 52 3
8,690 0.777 47 3,081 0.047 31 2
9,380 1.382 52 3,179 0.504 42 2
15,200 8.597 54 3,210 0.214 37 4
8,450 0.590 45 3,198 0.294 36 4
8,510 0.767 50 3,225 0.661 48 4
8,240 0.688 46 3,151 0.105 34 6
7,920 0.176 34 3,018
-0.087 22 5
8,250 0.583 46 3,202 0.583 45 5
8,490 0.972 49 3,131 0.068 31 7
8,180 0.379 37 3,071 0.025 30 6
7,770 0.244 39 3,038 0.024 29 6
8,010 0.426 45 3,144 0.092 32 10 7,780 0.066 32 3,324 0.561 44 8
7,580 0.110 33 3,233 0.688 49 8
7,720 0.097 33 3,499 0.746 48 11 7,980 0.223 35 3,245 0.394 38 10 7,600 0.124 34 3,043 0.041 30 9
7,830 0.222 38.5 3,271 0.326 42 17 7,670
-0.020 28 3,296 0.502 39 11 7,500 0.053 31 3,193 0.552 43 10 7,800 0.188 35 3,080
-0.026 28 19 7,220
-0.371 15 2,994
-0.138 19 12 7,350
-0.053 27 3,096 0.221 37 11 7,820 0.210 36 3,039
-0.101 25 23 6,570
-0.879 1
2,647
-0.873 2
14 7,560 0.095 32 3,024
-0.024 28 13 7,830 0.222 38.5 3,468 0.689 47 25 6,760
-0.730 5
2,697
-0.767 4
15 7,310
-0.081 26 3,132 0.344 40 14 7,560
-0.085 26 3,108 0.026 29 27 6,830
-0.676 8
2,761
-0.631 9
20 6,630
-0.562 9
3,068 0.126 35 19 7,670 0.040 30 2,849
-0.451 19 28 6,800
-0.699 7
2,682
-0.799 3
21 6,680
-0.527 10 2,844
-0.637 6
20 7,490
-0.165 24 2,608
-0.895 3
29 6,790
-0.707 6
2,779
-0.593 10 24 6,440
-0.696 5
2,807
-0.763 2
23 6,900
-0.835 6
2,489
-1.115 1
30 6,960
-0.574 11 2,819
-0.508 14 27 6,730
-0.491 13 2,940
-0.310 22 26 6,720
-1.040 2
2,610
-0.892 5
31 7,030
-0.520 13 2,938
-0.256 16 28 6,600
-0.583 8
2,955
-0.259 23 27 6,850
-0.892 4
2,686
-0.752 10 33 7,380
-0.246 17 2,795
-0.559 12 33 6,800
-0.442 15 2,894
-0.467 14 32 7,080
-0.631 14 2,765
-0.606 15 36 7,590
-0.082 23 3,047
-0.025 27 35 6,940
-0.343 20 2,880
-0.514 11.5 34 6,950
-0.778 8
2,777
-0.584 16 37 7,650
-0.035 26 3,030
-0.061 24 36 6,870
-0.392 17 2,855
-0.600 7
35 7,070
-0.642 13 2,854
-0.442 20 38 7,540
-0.121 20 3,003
-0.119 21 39 6,820
-0.428 16 2,814
-0.739 4
38 6,940
-0.790 7
2,708
-0.711 12 39 7,490
-0.160 18 3,042
-0.036 25 40 7,070
-0.251 24 2,813
-0.743 3
39 6,960
-0.767 9
2,707
-0.713 11 41 7,880 0.145 33 3,309 0.530 42 42 6,960
-0.329 21 2,880
-0.514 11.5 41 7,230
-0.460 18 2,967
-0.234 23 42 7,720 0.020 29 3,311 0.534 43 43 7,280
-0.102 25 2,927
-0.354 19 42 7,290
-0.392 21 3,242 0.273 41 44 8,350 0.512 40 4,588 3.239 53 45 7,750 0.230 38 3,085 0.184 36 44 7,380
-0.290 22 3,324 0.424 44 45 8,360 0.520 41 3,623 1.195 49 46 8,240 0.576 44 3,157 0.429 41 45 7,600
-0.040 27 3,724 1.161 50 46 8,550 0.668 46 3,726 1.413 50 47 9,290 1.318 51 2,926
-0.358 18 47 7,840 0.233 40 3,802 1.304 51 48 8,990 1.012 48 3,951 1.890 51 48 8,310 0.625 47 1,607
-4.852 1
48 7,990 0.403 43 2,840
-0.468 17 Loc. = Location Adj. Meas. = Adjusted Measurement R = Rank
Zion Containment and Auxiliary Penetrations B-5 5272-SR-04-0 Table B.3. (continued) Measurement Data Used for Students t-Test in Unit 1 Containment P123 P124 Loc.
FSS ORISE Loc.
FSS ORISE cpm Adj. Meas.
R cpm Adj. Meas.
R cpm Adj.
Meas.
R cpm Adj. Meas.
R 1
479,101 1.217 54 261,720 1.206 53 0
162,181 0.991 55 88,938 1.140 56 2
526,958 1.358 56 286,327 1.340 55 1
134,469 0.739 52 56,290 0.508 41 5
414,485 1.028 50 221,934 0.988 48 2
140,482 0.793 53 62,337 0.625 48 8
341,986 0.815 42 172,891 0.719 40 3
142,018 0.807 54 61,751 0.614 46 9
364,683 0.881 45 180,581 0.761 41 5
132,897 0.724 51 64,397 0.665 50 10 382,545 0.934 47 204,430 0.892 46 7
113,921 0.552 43 51,462 0.414 38 12 401,693 0.990 49 231,571 1.041 52 9
116,654 0.576 44 54,467 0.472 40 13 358,186 0.862 44 229,697 1.030 51 10 120,771 0.614 47 58,168 0.544 42 14 278,439 0.628 39 191,506 0.821 43 11 122,955 0.634 49 60,098 0.582 45 17 211,777 0.432 36 107,018 0.358 35 15 99,666 0.422 39 50,267 0.391 37 18 218,737 0.453 37 141,016 0.545 38 16 87,455 0.311 36 45,956 0.308 35 20 130,937 0.195 33 79,916 0.210 34 17 81,059 0.253 34 40,794 0.208 33 21 114,604 0.147 32 62,427 0.114 31 18 70,213 0.154 31 38,639 0.166 32 22 83,459 0.055 29 55,485 0.076 30 19 58,052 0.043 29 32,940 0.056 30 23 45,926
-0.055 28 27,689
-0.076 27 20 48,516
-0.043 28 27,189
-0.056 27 24 35,893
-0.085 26 16,049
-0.140 22 21 39,051
-0.129 26 23,047
-0.136 25 28 17,545
-0.138 23 9,760
-0.174 12 22 27,807
-0.232 24 16,579
-0.261 23 32 14,501
-0.147 21 5,811
-0.196 5
23 20,407
-0.299 22 11,543
-0.359 21 34 19,739
-0.132 25 8,604
-0.181 11 31 10,519
-0.389 20 4,458
-0.496 10 37 13,026
-0.152 17 6,638
-0.191 8
36 9,827
-0.395 18 4,073
-0.503 6
39 12,057
-0.155 14 5,224
-0.199 2
37 9,546
-0.398 16 3,855
-0.507 3
40 12,460
-0.153 16 5,753
-0.196 4
39 9,817
-0.395 17 4,144
-0.502 7
42 13,498
-0.150 18 6,051
-0.195 7
40 9,420
-0.399 15 4,321
-0.498 8
43 18,757
-0.135 24 8,102
-0.183 10 43 10,061
-0.393 19 4,335
-0.498 9
45 11,732
-0.156 13 5,850
-0.196 6
46 9,079
-0.402 14 3,980
-0.505 5
46 12,157
-0.154 15 5,019
-0.200 1
47 8,810
-0.405 11 3,755
-0.509 1
47 14,346
-0.148 20 5,547
-0.197 3
48 9,072
-0.402 13 3,837
-0.508 2
48 13,510
-0.150 19 7,598
-0.186 9
49 8,928
-0.404 12 3,893
-0.507 4
Loc. = Location Adj. Meas. = Adjusted Measurement R = Rank
Zion Containment and Auxiliary Penetrations B-6 5272-SR-04-0 Table B.4. Confirmatory Measurements in Unit 2 Penetrationsa P235 P236 P237 P323 P324 Loc.b Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2) 0 8,203 2.10E+06 0
7,630 1.96E+06 0
7,142 1.83E+06 0
8,269 2.12E+06 1
3,925 1.01E+06 4
3,074 7.88E+05 1
3,606 9.25E+05 2
2,907 7.45E+05 1
4,335 1.11E+06 2
3,303 8.47E+05 5
3,017 7.74E+05 4
2,968 7.61E+05 4
3,017 7.74E+05 2
3,530 9.05E+05 5
3,317 8.51E+05 7
2,955 7.58E+05 5
2,969 7.61E+05 8
2,951 7.57E+05 3
3,999 1.03E+06 6
3,573 9.16E+05 9
3,082 7.90E+05 8
2,772 7.11E+05 9
2,834 7.27E+05 5
5,086 1.30E+06 7
3,325 8.53E+05 10 3,068 7.87E+05 10 2,697 6.92E+05 13 3,025 7.76E+05 6
4,406 1.13E+06 10 3,463 8.88E+05 12 3,100 7.95E+05 11 2,716 6.96E+05 16 3,016 7.73E+05 8
9,883 2.53E+06 11 5,752 1.48E+06 14 3,035 7.78E+05 12 2,893 7.42E+05 18 3,290 8.44E+05 9
4,355 1.12E+06 12 3,349 8.59E+05 15 3,039 7.79E+05 13 2,846 7.30E+05 20 2,664 6.83E+05 12 3,521 9.03E+05 13 3,241 8.31E+05 16 3,031 7.77E+05 14 2,864 7.34E+05 22 2,500 6.41E+05 15 4,025 1.03E+06 14 3,332 8.54E+05 17 2,839 7.28E+05 15 2,956 7.58E+05 24 2,540 6.51E+05 17 7,786 2.00E+06 15 3,383 8.68E+05 19 2,929 7.51E+05 16 2,808 7.20E+05 25 2,297 5.89E+05 20 5,508 1.41E+06 17 5,321 1.36E+06 20 2,576 6.61E+05 17 2,791 7.16E+05 26 2,415 6.19E+05 22 3,404 8.73E+05 19 3,438 8.82E+05 21 2,738 7.02E+05 18 2,817 7.22E+05 27 2,440 6.26E+05 23 3,133 8.03E+05 20 3,625 9.30E+05 22 2,659 6.82E+05 21 2,548 6.53E+05 28 2,484 6.37E+05 24 3,063 7.85E+05 26 7,776 1.99E+06 23 2,504 6.42E+05 25 2,363 6.06E+05 29 2,496 6.40E+05 25 3,942 1.01E+06 27 3,683 9.44E+05 25 2,969 7.61E+05 28 2,509 6.43E+05 30 2,512 6.44E+05 26 5,916 1.52E+06 28 2,962 7.60E+05 26 2,615 6.71E+05 29 2,461 6.31E+05 33 2,488 6.38E+05 29 3,214 8.24E+05 29 2,805 7.19E+05 29 2,714 6.96E+05 34 2,500 6.41E+05 34 2,526 6.48E+05 31 2,936 7.53E+05 31 2,767 7.10E+05 31 2,442 6.26E+05 35 2,520 6.46E+05 35 2,495 6.40E+05 32 3,127 8.02E+05 32 2,811 7.21E+05 32 2,515 6.45E+05 37 2,472 6.34E+05 36 2,566 6.58E+05 34 3,103 7.96E+05 34 4,940 1.27E+06 33 2,586 6.63E+05 38 2,624 6.73E+05 37 2,544 6.52E+05 35 4,412 1.13E+06 36 5,769 1.48E+06 37 2,545 6.53E+05 39 2,605 6.68E+05 38 2,469 6.33E+05 37 3,450 8.85E+05 38 3,201 8.21E+05 40 2,632 6.75E+05 40 2,558 6.56E+05 42 2,622 6.72E+05 39 3,445 8.83E+05 40 2,983 7.65E+05
Zion Containment and Auxiliary Penetrations B-7 5272-SR-04-0 Table B.4. (continued) Confirmatory Measurements in Unit 2 Penetrationsa P235 P236 P237 P323 P324 Loc.b Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2)
Loc.
Gross Count (cpm)
Gross Surface Activity (pCi/m2) 41 2,692 6.90E+05 41 2,591 6.64E+05 43 2,600 6.67E+05 40 3,531 9.06E+05 43 4,505 1.16E+06 42 2,670 6.85E+05 44 2,513 6.44E+05 45 2,699 6.92E+05 41 3,655 9.37E+05 47 3,845 9.86E+05 47 2,746 7.04E+05 45 2,664 6.83E+05 48 2,528 6.48E+05 46 4,410 1.13E+06 48 4,581 1.17E+06 48 2,720 6.98E+05 48 2,669 6.84E+05 49 2,793 7.16E+05 48 5,188 1.33E+06 49 5,426 1.39E+06 17c 3,203 8.21E+05 44c 7,630 1.96E+06 35c 12,708 3.26E+06 aLudlum detector Model 44-157 used.
bLocation refers to the 1-foot pipe segment referenced from the origin, which is the termination of the penetration on the Auxiliary Building side.
cJudgmental measurement.
Loc. = Location
Zion Containment and Auxiliary Penetrations B-8 5272-SR-04-0 Table B.5. Measurement Data Used for Students t-Test in Unit 2 Containment P235 P236 P237 Loc.
FSS ORISE Loc.
FSS ORISE Loc.
FSS ORISE cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R 0
18,286 10.718 55 8,203 13.167 56 0
20,623 20.830 56 7,630 14.878 55 0
23,766 16.553 56 7,142 11.657 55 4
7,835 0.980 52 3,074 0.800 46 1
11,036 6.348 54 3,606 2.776 53 2
8,148 1.564 53 2,907 0.895 43 5
7,886 1.028 53 3,017 0.663 39 4
7,778 1.427 52 2,968 0.857 49 4
7,969 1.393 52 3,017 1.174 49 7
7,807 0.954 51 2,955 0.514 35 5
7,562 1.100 51 2,969 0.860 50 8
7,714 1.148 47 2,951 1.006 45 9
7,903 1.044 54 3,082 0.820 48 8
7,078 0.369 36 2,772 0.268 32 9
7,441 0.886 42 2,834 0.709 41 10 7,680 0.836 49 3,068 0.786 45 10 6,938 0.158 31 2,697 0.042 29 13 7,458 0.902 44 3,025 1.194 50 12 7,651 0.809 47 3,100 0.863 50 11 7,098 0.400 38 2,716 0.099 30 16 7,594 1.033 46 3,016 1.172 48 14 7,603 0.764 44 3,035 0.706 41 12 7,164 0.499 42 2,893 0.632 47 18 7,774 1.205 51 3,290 1.868 54 15 7,473 0.643 38 3,039 0.716 43 13 7,035 0.304 33 2,846 0.490 41 20 6,577 0.057 34 2,664 0.277 38 16 7,549 0.714 42 3,031 0.697 40 14 7,077 0.368 35 2,864 0.544 44 22 6,519 0.001 29 2,500
-0.140 11 17 7,463 0.634 37 2,839 0.234 33 15 7,143 0.468 40 2,956 0.821 48 24 6,533 0.014 30 2,540
-0.038 25 19 6,976 0.180 32 2,929 0.451 34 16 7,181 0.525 43 2,808 0.376 37 25 6,348
-0.163 7
2,297
-0.656 1
20 6,815 0.030 31 2,576
-0.400 5
17 7,245 0.622 46 2,791 0.325 34 26 6,517
-0.001 28 2,415
-0.356 2
21 6,669
-0.106 21 2,738
-0.010 27 18 7,225 0.591 45 2,817 0.403 39 27 6,544 0.025 31 2,440
-0.292 3
22 6,562
-0.206 15 2,659
-0.200 16 21 6,583
-0.378 17 2,548
-0.406 16 28 6,571 0.051 33 2,484
-0.180 5
23 6,385
-0.371 7
2,504
-0.574 2
25 6,302
-0.803 2
2,363
-0.962 1
29 6,410
-0.104 16.5 2,496
-0.150 9
25 6,452
-0.308 9
2,969 0.547 36 28 6,410
-0.640 5
2,509
-0.523 10 30 6,410
-0.104 16.5 2,512
-0.109 15 26 6,697
-0.080 24 2,615
-0.306 10 29 6,427
-0.614 8
2,461
-0.668 4
33 6,367
-0.145 10 2,488
-0.170 6
29 6,577
-0.192 17 2,714
-0.068 25 34 6,499
-0.505 12 2,500
-0.550 9
34 6,397
-0.116 13 2,526
-0.074 19 31 6,553
-0.214 14 2,442
-0.723 1
35 6,320
-0.776 3
2,520
-0.490 13 35 6,475
-0.041 24 2,495
-0.152 8
32 6,431
-0.328 8
2,515
-0.547 3
37 6,415
-0.632 7
2,472
-0.635 6
36 6,443
-0.072 20 2,566 0.028 32 33 6,464
-0.297 11 2,586
-0.376 6
38 6,618
-0.326 20 2,624
-0.177 25 37 6,401
-0.112 14 2,544
-0.028 27 37 6,680
-0.096 22.5 2,545
-0.475 4
39 6,729
-0.158 26 2,605
-0.235 23 38 6,581 0.060 35 2,469
-0.219 4
40 6,492
-0.271 12 2,632
-0.265 13 40 6,646
-0.283 21 2,558
-0.376 18 42 6,485
-0.032 26 2,622 0.170 37 41 6,645
-0.129 19 2,692
-0.121 20 41 6,511
-0.487 14 2,591
-0.277 22 43 6,417
-0.097 18 2,600 0.114 36 42 6,680
-0.096 22.5 2,670
-0.174 18 44 6,526
-0.465 15 2,513
-0.511 11 45 6,448
-0.067 22 2,699 0.366 39 47 6,789 0.006 29 2,746 0.010 30 45 6,710
-0.187 24 2,664
-0.057 27 48 6,386
-0.127 12 2,528
-0.069 21 48 6,777
-0.006 28 2,720
-0.053 26 48 6,592
-0.365 19 2,669
-0.042 28 49 6,466
-0.050 23 2,793 0.605 40 Loc. = Location Adj. Meas. = Adjusted Measurement R = Rank
Zion Containment and Auxiliary Penetrations B-9 5272-SR-04-0 Table B.5. (continued) Measurement Data Used for Students t-Test in Unit 2 Containment P323 P324 Loc.
FSS ORISE Loc.
FSS ORISE cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R cpm Adj.
Meas.
R 0
27,627 4.485 55 8,269 2.859 53 1
10,502 0.923 44 3,925 0.363 39 1
35,806 6.483 56 4,335 0.242 34 2
8,335 0.033 30 3,303
-0.113 15 2
12,965 0.904 46 3,530
-0.293 18 5
8,161
-0.039 24.5 3,317
-0.102 17 3
9,929 0.162 32 3,999 0.019 29 6
7,993
-0.108 16 3,573 0.094 34 5
12,027 0.675 42 5,086 0.742 44 7
8,477 0.091 33 3,325
-0.096 18 6
12,091 0.690 43 4,406 0.290 36 10 7,868
-0.159 13 3,463 0.010 29 8
15,367 1.491 50 9,883 3.933 54 11 8,078
-0.073 21 5,752 1.763 51 9
14,843 1.363 49 4,355 0.256 35 12 7,976
-0.115 14 3,349
-0.078 20 12 9,180
-0.021 27 3,521
-0.299 17 13 8,087
-0.069 22 3,241
-0.160 12 15 9,349 0.021 30 4,025 0.036 31 14 8,175
-0.033 27 3,332
-0.091 19 17 15,584 1.544 51 7,786 2.538 52 15 8,350 0.039 31 3,383
-0.052 23 20 9,055
-0.051 26 5,508 1.023 47 17 10,152 0.779 41 5,321 1.433 47 22 7,949
-0.321 16 3,404
-0.377 11 19 8,359 0.043 32 3,438
-0.010 28 23 7,656
-0.393 10 3,133
-0.557 5
20 8,875 0.255 37 3,625 0.134 35 24 7,437
-0.446 7
3,063
-0.604 2
26 12,457 1.726 50 7,776 3.313 56 25 8,127
-0.278 21 3,942
-0.019 28 27 8,170
-0.035 26 3,683 0.178 36 26 10,502 0.302 39 5,916 1.294 48 28 7,331
-0.380 7
2,962
-0.374 8
29 7,740
-0.372 12 3,214
-0.503 6
29 7,175
-0.444 5
2,805
-0.494 2
31 7,486
-0.434 8
2,936
-0.688 1
31 7,094
-0.477 4
2,767
-0.524 1
32 7,493
-0.433 9
3,127
-0.561 4
32 7,372
-0.363 9
2,811
-0.490 3
34 8,199
-0.260 23 3,103
-0.577 3
34 13,792 2.275 54 4,940 1.141 45 35 10,211 0.231 33 4,412 0.294 38 36 12,604 1.787 53 5,769 1.776 52 37 8,271
-0.243 24 3,450
-0.346 14 38 8,161
-0.039 24.5 3,201
-0.191 11 39 7,893
-0.335 15 3,445
-0.350 13 40 7,305
-0.390 6
2,983
-0.358 10 40 8,078
-0.290 20 3,531
-0.292 19 43 14,172 2.431 55 4,505 0.808 42 41 8,177
-0.266 22 3,655
-0.210 25 47 9,366 0.456 40 3,845 0.302 38 46 10,537 0.311 40 4,410 0.292 37 48 11,841 1.473 48 4,581 0.866 43 48 11,036 0.433 41 5,188 0.810 45 49 11,270 1.239 46 5,426 1.513 49 Loc. = Location Adj. Meas. = Adjusted Measurement R = Rank
Zion Containment and Auxiliary Penetrations 5272-SR-04-0 APPENDIX C: SURVEY AND ANALYTICAL PROCEDURES
Zion Containment and Auxiliary Penetrations C-1 5271-SR-04-0 C.1.
PROJECT HEALTH AND SAFETY The Oak Ridge Institute for Science and Education (ORISE) performed all survey activities in accordance with the Oak Ridge Associated Universities (ORAU) Radiation Protection Manual, the ORAU Health and Safety Manual, and the ORAU Radiological and Environmental Survey Procedures Manual (ORAU 2014, ORAU 2016b, and ORAU 2016a). Prior to on-site activities, a work-specific hazard checklist was completed for the project and discussed with field personnel. The planned activities were thoroughly discussed with site personnel prior to implementation to identify hazards present.
Additionally, prior to performing work, a pre-job briefing and walkdown of the survey areas were completed with field personnel to identify hazards present and discuss safety concerns. Should ORISE have identified a hazard not covered in the ORAU Radiological and Environmental Survey Procedures Manual (ORAU 2016a) or the projects work-specific hazard checklist for the planned survey and sampling procedures, work would not have been initiated or continued until the hazard was addressed by an appropriate job hazard analysis and hazard controls.
C.2.
QUALITY ASSURANCE Field survey and laboratory activities were conducted in accordance with procedures from the following documents:
- ORAU Radiological and Environmental Survey Procedures Manual (ORAU 2016a)
- ORAU Radiological and Environmental Analytical Laboratory Procedures Manual (ORAU 2017)
- ORAU Environmental Services and Radiation Training Quality Program Manual (ORAU 2018)
The procedures contained in these manuals were developed to meet the requirements of U.S. Department of Energy (DOE) Order 414.1D and the U.S. Nuclear Regulatory Commission (NRC) Quality Assurance Manual for the Office of Nuclear Material Safety and Safeguards, and contain measures to assess processes during their performance.
Zion Containment and Auxiliary Penetrations C-2 5271-SR-04-0 Quality control procedures include:
- Daily instrument background and check-source measurements to confirm that equipment operation is within acceptable statistical fluctuations.
- Participation in Mixed-Analyte Performance Evaluation Program and Intercomparison Testing Program laboratory quality assurance programs.
- Training and certification of all individuals performing procedures.
- Periodic internal and external audits.
C.3 PIPE DETECTOR CALIBRATION Efficiency factors representing the total gamma-emitting radionuclide of concern (ROC) activity for the sodium iodide (NaI)/cesium iodide (CsI) detector were determined based on the diameter of the measured penetration. Calibration of all field instrumentation was based on standards/sources traceable to the National Institute of Standards and Technology (NIST). A Cs-137 line source, approximately 30 centimeters (cm) in length, was used for the efficiency determination of each detector. The calibration source was continuously rotated around the detector at constant speed using a motorized jig during measurement acquisition. Rotating the source simulates a large-area source distributed over a cylindrical geometry. Based on the length of the calibration standard, the area represented by each static measurement will be the surface area of a 1-foot long segment of pipe/penetration. Figure C.1 depicts the calibration geometry from the top down (looking into the penetration).
Figure C.1. Detector Calibration Geometry
Zion Containment and Auxiliary Penetrations C-3 5271-SR-04-0 Direct measurements were converted to surface activity units by:
100 2=
xx 1
2.22 (Equation C-1)
Where pCi = picocurie cm2 = square centimeter Rgross = the gross static measurement count rate, uncorrected for background
= detector efficiency G = Source area modification factor representing the surface area of a 1-linear-foot section of the penetration, which is 0.56 m2 for a 23-inch diameter penetration. The detector field of view covers significantly more than this area. Previous ORISE pipe detector calibrations demonstrate that approximately 90% of the detector response to a point source (relative to the source centered with the detector midpoint) occurs within 15 cm from the detector midpoint.
dpm = disintegrations per minute The static minimum detectable concentration (MDC) in units of pCi/square meter (m2) was calculated by
100 2=
3+4.65 x
x 1
2.22 (Equation C-2)
Where Bkg = Background count rate, which is assumed to be 4,000 counts per minute (cpm)
Factors and G in Equation C-2 are the same as presented in Equation C-1. A summary of efficiency factors and corresponding MDCs for varying penetration/pipe diameters are presented in Table C.1.
Zion Containment and Auxiliary Penetrations C-4 5271-SR-04-0 Table C.1. Detector Efficiency and MDC Summary Duct Diameter (in)
Bkg (cpm)a G (m2)
MDC (pCi/m2)
Comment NaI Detector - Model 44-157 6
9,750 1.22E-02 0.15 1.17E+05 Applies to Aux waste disposal penetration A023 23 9,750 3.14E-03 0.56 1.19E+05 Applies to penetrations in the cavity flood sump and rx recirc sump CsI Detector - Model 44-159-1 1.5 750 3.82E-03 0.04 4.21E+05 Applies to in-core discharge embedded piping 1.97 750 3.13E-03 0.05 3.92E+05 Applies to Aux waste disposal penetration A011 aBackground taken as typical value from manufacturer manual. Site-specific values were not determined; however this value is a conservative estimate.
C.4 RADIOLOGICAL SAMPLE ANALYSIS Miscellaneous sample 5271M0038 contained multiple matrices, including the cloth wipe, some debris-residue material, some type of rubber/silicone seal, and a personal protective equipment (PPE) glove that was used to obtain the sample. The entire sample was analyzed by gamma spectrometry in a 250 milliliter (mL) marinelli beaker, and multiple radionuclides were identified, including, but not limited to, Am-241. To further determine where the radionuclides were concentrated within the sample, the sample was split into four different portions and placed into corresponding smaller gamma spectrometry calibrated geometries containers. The cloth wipe was cut into two pieces and each piece was placed in its own container and labeled, respectively, swipe 1 and swipe 2. The debris-residue was put into one container and labeled residue 1. The glove and seal were placed into another container and labeled glove-seal. Each container then was counted via gamma spectroscopy. The container labeled swipe 1 was identified to contain the Am-241. While the other three containers were identified to have other minor residual contamination, Am-241 was not identified in these three containers.
C.4.1 Gamma Spectroscopy Samples were counted using intrinsic, high-purity, germanium detectors coupled to a pulse-height analyzer system. Background and Compton stripping, peak search, peak identification, and concentration calculations were performed using the computer capabilities inherent in the analyzer system. All total absorption peaks (TAPs) associated with the ROCs were reviewed for consistency of activity. Spectra also were reviewed for other identifiable TAPs. TAPs used for determining the
Zion Containment and Auxiliary Penetrations C-5 5271-SR-04-0 activities of ROCs and the associated MDCs for a 1-hour count time are presented in Table C.2.
Gamma spectrometry values reported in this document were based on the initial count of the sample in the 250 mL marinelli beaker. It was noted that only one portion of the swipe contained Am-241, and that same portion contained the majority of the gamma activity.
Table C.2. MDCs and Total Absorption Peak Radionuclide TAP (MeV)a MDC (pCi/sample)
Co-60 1.332 60 Cs-134 0.795 109 Cs-137 0.662 90 Eu-152 0.344 151 Eu-154 0.723 400 a mega electron volt C.4.2 Americium-241 Analysis by Alpha Spectrometry The swipe portion that contained Am-241 was placed in a 250-mL platinum dish and the dish was placed into a muffle furnace, which was slowly ramped up to 900oC. The remaining residue was first acid extracted with 1M HCL to remove elemental iron. This liquid fraction was held back to later return to the fused sample. The remaining solid residue was returned to the platinum dish and fused by a fluoride-pyrosulfate fusion. The sample was completely dissolved. The fusion cake was dissolved in 500 mL of 2M HCL with heat. The initial 1M HCL extraction was added back to the sample. The sample was diluted to 1000 mL with 1M HCL; 100 mL of the sample was used for Am-241 analysis, including a duplicate. Because of anticipated activity levels of 15-20 pCi/100 mL, the sample was spiked with Am-243 at similar levels. Analysis proceeded with no deviations. In addition to Am-241, Cm-244 was identified in the sample; however, the value determined by the software is an estimated value (biased low). Accurate analysis of the curium isotopes requires minor procedural changes to eliminate the low bias.
Zion Containment and Auxiliary Penetrations 5271-SR-04-0 APPENDIX D: MAJOR INSTRUMENTATION
Zion Containment and Auxiliary Penetrations D-1 5271-SR-04-0 The display of a specific product is not to be construed as an endorsement of the product or its manufacturer by the author or his employer.
D.1 SCANNING AND MEASUREMENT INSTRUMENT/DETECTOR COMBINATIONS D.1.1 Gamma Ludlum NaI Scintillation Detector Model 44-157, Crystal: 5.1 cm x 5.1 cm coupled to: Ludlum Ratemeter-scaler Model 2221 Ludlum CsI Scintillation Detector Model 44-159-1, Crystal: 1.8 cm x 1.8 cm coupled to: Ludlum Ratemeter-scaler Model 2221 D.2 LABORATORY ANALYTICAL INSTRUMENTATION High-Purity, Extended Range Intrinsic Detector CANBERRA/Tennelec Model No: ERVDS30-25195 (Canberra, Meriden, Connecticut)
Used in conjunction with:
Lead Shield Model G-11 (Nuclear Lead, Oak Ridge, Tennessee) and Multichannel Analyzer Canberras Gamma Software Dell Workstation (Canberra, Meriden, Connecticut)
High-Purity, Intrinsic Detector EG&G ORTEC Model No. GMX-45200-5 Used in conjunction with:
Lead Shield Model G-11 Lead Shield Model SPG-16-K8 (Nuclear Data)
Multichannel Analyzer Canberras Gamma Software Dell Workstation (Canberra, Meriden, Connecticut)
High-Purity, Intrinsic Detector EG&G ORTEC Model No. GMX-30P4 Used in conjunction with:
Lead Shield Model G-11 Lead Shield Model SPG-16-K8 (Nuclear Data)
Multichannel Analyzer Canberras Gamma Software Dell Workstation (Canberra, Meriden, Connecticut)
Zion Containment and Auxiliary Penetrations D-2 5271-SR-04-0 High-Purity, Intrinsic Detector EG&G ORTEC Model No. CDG-SV-76/GEM-MX5970-S Used in conjunction with:
Lead Shield Model G-11 Lead Shield Model SPG-16-K8 (Nuclear Data)
Multichannel Analyzer Canberras Gamma Software Dell Workstation (Canberra, Meriden, Connecticut)
CANBERRA Alpha AnalystTM Integrated Alpha Spectrometer System with A450-18AM Alpha Passivated Implanted Planar Silicon detectors Used in conjunction with:
CANBERRA Apex-Alpha software v.1.2.0.56