ML19077A042
| ML19077A042 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 09/20/2018 |
| From: | Giza P ZionSolutions |
| To: | Office of Nuclear Material Safety and Safeguards |
| References | |
| ZS-2019-0017 | |
| Download: ML19077A042 (33) | |
Text
ZION STATION RESTORATION PROJECT FINAL STATUS SURVEY RELEASE RECORD U1 CONTAINMENT INCORE SUMP DISCHARGE PIPE SURVEY UNIT 01111 (No. P125)
FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
PREPARED BY / DATE: Patsy Giza 9/20/2018 Radiological Engineer REVIEWED BY / DATE: R.F. Decker 9/20/2018 Radiological Engineer APPROVED BY / DATE: D. Wojtkowiak 9/20/2018 C/LT Manager
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
TABLE OF CONTENTS
- 1. EXECUTIVE
SUMMARY
................................................................................................... 4
- 2. SURVEY UNIT DESCRIPTION ......................................................................................... 4
- 3. CLASSIFICATION BASIS .................................................................................................. 5 4 DATA QUALITY OBJECTIVES ........................................................................................ 5 5 SURVEY DESIGN................................................................................................................. 7
- 6. SURVEY IMPLEMENTATION........................................................................................ 13
- 7. SURVEY RESULTS............................................................................................................ 14
- 8. QUALITY CONTROL........................................................................................................ 16
- 9. INVESTIGATIONS AND RESULTS................................................................................ 16
- 10. REMEDIATION AND RESULTS ..................................................................................... 16
- 11. CHANGES FROM THE SURVEY PLAN........................................................................ 16
- 12. DATA QUALITY ASSESSMENT (DQA) ........................................................................ 17
- 13. ANOMALIES....................................................................................................................... 17
- 14. CONCLUSION .................................................................................................................... 17 15 REFERENCES..................................................................................................................... 18
- 16. ATTACHMENTS ................................................................................................................ 18 ATTACHMENT 1 - FIGURES AND MAPS ..................................................................... 19 ATTACHMENT 2 - SAMPLE DATA................................................................................ 21 ATTACHMENT 3 - SIGN TEST........................................................................................ 27 ATTACHMENT 4 - QC DATA .......................................................................................... 29 ATTACHMENT 5 - GRAPHICAL PRESENTATIONS ................................................. 31 LIST OF TABLES Table 1 - Dose Significant Radionuclides and Mixture....................................................................6 Table 2 -Base Case and Operational DCGLs...................................................................................7 Table 3 - Surrogate Ratios for Containment ....................................................................................8 Table 4 - Typical FSS Instrument Detection Sensitivities..............................................................11 Table 5 - Synopsis of Survey Design..............................................................................................12 Table 6 - Survey Data Collected.....................................................................................................13 Table 7 - Instrument and detector ...................................................................................................14 Table 8 - Unit 1 Incore Sump Discharge Pipe (P125)- Statistical Summary.................................16
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
- 1. EXECUTIVE
SUMMARY
This Final Status Survey (FSS) Release Record for Survey Unit #S1-01111, Unit 1 Containment In-Core Sump Discharge Pipe (No. P125) has been generated for the Zion Station Restoration Project (ZSRP). The release record was developed in accordance with ZionSolutions procedure ZS-LT-300-001-005, Final Status Survey Data Reporting (Reference 1) and satisfies the requirements of Section 5.11 of the ZSRP License Termination Plan (LTP) (Reference 2).
FSS Sample Plan #S1-01111AF was developed in accordance with ZionSolutions procedure ZS-LT-300-001-001, Final Status Survey Package Development (Reference
- 3) the ZSRP LTP, and guidance from NUREG-1575, Revision 1, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (Reference 4).
A FSS is conducted to demonstrate that the concentrations of residual radioactivity are equal to or below site-specific Derived Concentration Guideline Levels (DCGL) corresponding to the dose criterion in 10 CFR 20.1402. The Unit 1 Containment In-Core Sump Discharge Pipe (P125) is classified as MARSSIM Class 1.
Measurements were collected at 1 foot intervals inside the pipe which has a 1.61 inch Internal Diameter (ID). The Ludlum 2350-1 Data Logger paired with a Ludlum Model 44-159 Cesium Iodide (CsI) gamma detector was selected to survey 26.74 linear feet with a surface area of 1.05 m2 to provide 100% coverage requirement for a Class 1 survey unit.
Due to an obstruction (90 degree elbow), 22 measurements were taken to achieve 100%
areal coverage of the accessible internal surface which equated to a surface area of 0.86 m2.
For the FSS of the In-Core Sump Discharge Pipe, 22 readings were obtained. 21 readings were below a Sum-of-Fraction (SOF) of 1.0 when compared against the Operational DCGL (OpDCGLEP) with a mean OpSOF of 0.1044. Compared against the Base Case DCGL (BcDCGLEP), the mean SOF was 0.0484, which equated to a dose of 1.2093 mrem/yr.
- 2. SURVEY UNIT DESCRIPTION The Unit 1 Containment In-Core Sump Discharge Pipe is 1.61 inch ID embedded pipe located in the concrete of the Incore Access Tunnel in Unit-1. The incore area extends below the containment slab and consists of a cylindrical area directly under the reactor vessel biological shield and a sloped tunnel. The incore area walls are 1 foot 11.5 inches thick (23.5 inches) with a 2 foot 6 inches under vessel area floor thickness. There is also an access tunnel with 15 inch thick walls, floor and roof. The sump is 2 ft. x 2 ft. x 2 ft.
approximately 1 foot from the bend line. The pipe enters the wall at the floor above the sump making the opposite of the triangle 17 feet plus 9.5 feet or 22.5 feet. The base is 43
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125) feet minus 30 feet 9-inches making the hypotenuse length 25.74 feet assuming the pipe enters the wall approximately 1 foot before sloping upward results in an estimated length of 26.74 feet (8.15 meters) and 1.05 m2 surface areas. Twenty-seven (27) measurements were planned to be taken but only 22 feet of the pipe was accessible for survey.
- 3. CLASSIFICATION BASIS Survey Unit #S1-01111 embedded pipe No. P125 was classified in accordance with ZionSolutions procedure ZS-LT-300-001-002, Survey Unit Classification (Reference 5).
Based on information from the Zion Station Historical Site Assessment (HSA),
(Reference 6), the In-Core Sump Discharge Pipe is located in a Class 1 area. The Under Vessel Incore area was subjected to operational conditions as well as the exercising of the in-core detectors. The Unit 1 In-Core Sump Discharge Pipe contained radioactive material and was classified as a Class 1 system.
4 DATA QUALITY OBJECTIVES Final Status Survey planning and design hinges on coherence with the Data Quality Objective (DQO) process to ensure, through compliance with explicitly defined inputs and boundaries, that the primary objective of the survey is satisfied. The DQO process is described in the ZSRP LTP in accordance with MARSSIM. The appropriate design for a given survey will be developed using the DQO process as outlined in Appendix D of MARSSIM.
The DQO process incorporated hypothesis testing and probabilistic sampling distributions to control decision errors during data analysis. Hypothesis testing is a process based on the scientific method that compares a baseline condition to an alternate condition. The baseline condition is technically known as the null hypothesis. Hypothesis testing rests on the premise that the null hypothesis is true and that sufficient evidence must be provided for rejection. In designing the survey plan, the underlying assumption, or null hypothesis was that residual activity in the survey unit exceeded the release criteria. Rejection of the null hypothesis would indicate that residual activity within the survey unit does not exceed the release criteria. Therefore, the survey unit would satisfy the primary objective of the FSS sample plan.
The primary objective of the FSS sample plan is to demonstrate that the level of residual radioactivity in Survey Unit #S1-01111 did not exceed the release criteria specified in the LTP and that the potential dose from residual radioactivity is As Low As Reasonably Achievable (ALARA).
LTP Chapter 6, section 6.5.2 discusses the process used to derive the ROC for the decommissioning of ZSRP, including the elimination of insignificant dose contributors
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
(IC) from the initial suite. In accordance with LTP Chapter 6, Table 6-2, the ROC for Containments include: Cs-137, Co-60, Sr-90, Cs-134, Ni-63, H-3, Eu-152 and Eu-154.
The residual radioactivity in embedded piping located below the 588 foot grade that will remain and be subjected to FSS is discussed in LTP Chapter 2, section 2.3.3.7 and TSD 14-016, Description of Embedded Piping, Penetrations, and Buried Pipe to Remain in Zion End State (Reference 7). The DCGLs for embedded piping are listed in LTP Chapter 5, sections 5.2.7 and 5.2.8.
For the Unit 1 In-Core Sump Discharge Pipe (P125), the suite of ROC and radionuclide mixture derived for the Containment concrete was considered as a reasonable conservative mixture to apply to the Unit 1 In-Core Sump Discharge Pipe (P125) for FSS planning and implementation. Table 1 reproduces the ROC from LTP Chapter 5, Table 5-2.
Table 1 - Dose Significant Radionuclides and Mixture Containment Radionuclide % of Total Activity (normalized)(1)
H-3 0.08 Co-60 4.72 Ni-63 26.50 Sr-90 0.03 Cs-134 0.01 Cs-137 68.17 Eu-152 0.44 Eu-154 0.06 (1) Based on maximum percent of total activity from Table 20 of TSD 14-019, normalized to one for the dose significant radionuclides.
A FSS is conducted on the interior surfaces of embedded piping to demonstrate that the concentrations of residual activity are equal to or below DCGLs corresponding to the dose criterion in 10CFR20.1402 (DCGLEP). DCGLEP were calculated for each of the remaining embedded pipe systems. The DCGLEP values for the Unit 1 In-Core Sump Discharge Pipe (P125) embedded pipe system from LTP Chapter 6, section 6.13 are referred to as Base Case DCGLs.
At ZNPS, compliance is demonstrated through the summation of dose from four distinct source terms for the end-state (basements, soils, buried pipe and groundwater). Each radionuclide-specific Base Case DCGL is equivalent to the level of residual radioactivity
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
(above background levels) that could, when considered independently, result in a Total Effective Dose Equivalent (TEDE) of 25 mrem per year to an Average Member of the Critical Group (AMCG). To ensure that the summation of dose from each source term is 25 mrem/year or less after all FSS is completed, the Base Case DCGLs are reduced based on an expected, or a priori, fraction of the 25 mrem/year dose limit from each source term.
The reduced DCGLs, or Operational DCGLs can be related to the 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 (calculation of surrogate DCGLs, investigations levels, etc.).
Details of the Operational DCGLs derived for each dose component and the basis for the applied a priori dose fractions are provided in ZionSolutions TSD 17-004, Operational Derived Concentration Guideline Levels for Final Status Survey (Reference 8).
The Base Case and Operational DCGLs for the In-Core Sump Discharge Pipe are listed in Tables 5-11 and 5-12 of the LTP.
Table 2 - Base Case and Operational DCGLs Base Case Operational Unit 1 & Unit 2 Unit 1 & Unit 2 Radionuclide Containment In Core Sump Containment In Core Sump Embedded Drain Pipe Embedded Drain Pipe H-3 8.28E+09 6.62E+08 Co-60 5.47E+09 4.38E+08 Ni-63 1.40E+11 1.12E+10 Sr-90 4.98E+07 3.98E+06 Cs-134 1.05E+09 8.40E+07 Cs-137 1.37E+09 1.10E+08 Eu-152 1.28E+10 1.02E+09 Eu-154 1.11E+10 8.88E+08 5 SURVEY DESIGN The level of effort associated with planning a survey is based on the complexity of the survey and nature of the hazards. Guidance for preparing FSS plans is provided in procedure ZS-LT-300-001-001 Final Status Survey Package Development.
Using the surrogate ratios in Table 3 and equation 1 from LTP Chapter 5, section 5.2.11, an adjusted gross gamma Operational DCGL was calculated by applying the normalized gamma for Eu-152, Eu-154, Cs-137, Cs-134 and Co-60, mixture from Table 1. The DCGLs are scaled and the most limiting value is used to determine the action level in dpm. The most limiting scaled DCGL value is 2.40E+07 pCi/m 2 (Co-60). The maximum ratios from LTP Chapter 5, Table 5-15 are reproduced below in Table 3.
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
Table 3 - Surrogate Ratios for Containment Containment Ratios Mean Max 95%UCL H-3/Cs-137 0.208 1.760 0.961 Ni-63/Co-60 30.623 442.317 193.910 Sr-90/Cs-137 0.002 0.021 0.010 For the FSS of Survey Unit #S1-01111 (P125), the surrogate Operational DCGLs for H-3, Co-60 and Cs-137 were computed based on the maximum ratios from Table 3.
The equation for calculating a surrogate DCGL is as follows:
Equation 1 Where: DCGLSur = Surrogate radionuclide DCGL DCGL2,3n = DCGL for radionuclides to be represented by the surrogate Rn = Ratio of concentration (or nuclide mixture fraction) of radionuclide n to surrogate radionuclide Using the Operational DCGLs presented in Table 2 and the maximum ratios from Table 3, the following surrogate calculations were performed:
Equation 2 (Co-60 Surrogate Operational DCGL)
Equation 3 (Cs-137 Surrogate Operational DCGL)
The survey design calculated a surrogate gross gamma Operational DCGL of 5.40E+07 pCi/m2.
Equation 4
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
The normalized gamma mixture was applied to the Operational DCGLs for the gamma emitting nuclides in Table 2 in the following equation:
Equation 5 (Gross Gamma Activity DCGL)
The Gross Activity DCGL was then used in the surrogate equation using the surrogate ratios from Table 3:
The Unit 1 Incore Discharge Sump Pipe (P125) is Class 1 embedded pipe. For the survey of pipe internal surfaces, areal coverage is achieved by the area of detection for each static measurement taken. Scanning, in the traditional context, is not applicable to the survey of pipe internal surfaces. For the survey of these pipes, the efficiency for the pipe detector was derived for the specific geometry of the 1.61-inch ID pipe.
The Unit 1 Incore Discharge Sump Pipe (P125) contains 26.74 linear feet of 1.61-inch ID piping, which equates to a surface area of 1.05 m2. The SeeSnakeTM camera was inserted 22 feet into the pipe. Because the entire length of the pipe was not accessible due to a 90 degree elbow, it was decided to take 22 measurements which equated to 0.86 m 2 surface area. The LTP states that a FSS Class 1 survey unit shall have a minimum areal coverage of 100%. Therefore, one measurement was to be collected every 1 foot of piping traversed for a total of 22 distinct measurements over the entire accessible pathway of the piping system. For quality control purposes, a minimum of 5% of the measurements collected were to be duplicated. This would require an additional 3 measurements to be collected throughout the length of the accessible surface of the piping system at locations selected at random.
Each static measurement represents the gamma activity in gross cpm for each specific measurement location. This gamma measurement value in cpm was then converted to dpm using an efficiency factor based on the calibration source in a comparable geometry.
The total activity in dpm is then adjusted for the assumed total effective surface area commensurate with the pipe/penetration diameter, resulting in measurement results in units of dpm per cm2. The total gamma surface activity for each FSS measurement is converted to a gamma measurement result (in units of pCi/m2) for each gamma ROC based on the normalized gamma mixture from Table 1. Concentrations for HTD ROC are inferred using the surrogate approach presented earlier in this release record.
The unity rule is applied when there is more than one ROC. The measurement results for each singular ROC present in the mixture are compared against their respective DCGL to derive a dose fraction. The summation of the dose fractions for each ROC produces a SOF for the measurement. When compared against the Base Case DCGL, the term is
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125) defined as BcSOF. When compared against the Operational DCGL, the term is defined as OpSOF.
To demonstrate that each survey unit satisfies the Operational DCGL, the ROC concentration for each systematic measurement taken in the Unit 1 In-Core Sump Discharge Pipe was divided by its applicable Operational DCGL (OpDCGLEP for embedded pipe) to derive a OpSOF for the ROC. The OpSOF for each ROC was then summed to determine the total OpSOF for all ROC that represents the measurement and was used as the summed value (Ws) for performing the Sign Test.
Embedded pipe survey units have a relatively small surface area leading to Operational DCGLs that are higher than the wall/floor Operational DCGLs. The reason for this is that the total internal surface area of the embedded pipe survey unit in a given basement is much less than the totals wall/floor surface area of the basement containing them. To eliminate the potential for activity levels in embedded pipe that could lead to releases greater than surrounding walls and floors, the following remediation and grouting action levels were applied to measurements of surface activity in embedded pipe.
If maximum activity exceeds the Base Case DCGLEP from Table 2 (SOF >1), then remediation was performed.
If the maximum activity in an embedded pipe exceeded the surface Operational DCGLB from LTP Chapter 5, Table 5-4 in the building that contains it, but was below the Base Case DCGLEP from Table 2, then the embedded pipe was remediated or grouted.
If an embedded pipe was remediated and the maximum activity continues to exceed the surface Operational DCGLB from LTP Chapter 5, Table 5-4, but is less than the Operational DCGLEP from Table 3, then the embedded pipe was grouted.
If the maximum activity was below the surface Operational DCGLB from LTP Chapter 5, Table 5-4, then grouting of the pipe was not required.
The instrumentation used for the FSS of the Unit 1 In-Core Sump Discharge Pipe (P125) was the Ludlum Model 2350-1 and the Model 44-159 detector. The instrumentation sensitivities are provided in Chapter 5 of the LTP and are reproduced in Table 4.
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
Table 4 - Typical FSS Instrument Detection Sensitivities BKGD Typical Typical Count Instrument Static MDC Scan MDC Radiation count time BKGD Instrument Time
/Detector (dpm/100 cm2) (dpm/100 cm2)
(min.) (cpm) Efficiencyab (min.)
Ludlum 2350-1/ 44- Gamma 1 700 0.024 1 5,250 N/A 159 a) Typical calibration source used is Cs-137. The efficiency is determined by counting the source with the detector in a fixed position from the source (reproducible geometry). The value is based on ISO-7503-1 and conditions noted for each detector.
b) The efficiency varies for the pipe detectors depending on the pipe diameter used. The efficiency used for the table is the average efficiency value for the pipe diameters. The detectors and diameters are: Model 44-159: 2-4 in. dia., Model 44-157:
4-8 in. dia., Model 44-162: 8-12 in. diameter.
In compliance with ZS-LT-01, Quality Assurance Project Plan (QAPP) for Characterization and Final Status Survey (Reference 9), replicate measurements were to be performed on 5% of the static measurement locations.
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
Table 5 - Synopsis of Survey Design FEATURE DESIGN CRITERIA BASIS Survey Unit Area 0.86 m2 Number of Static 22 100% areal coverage, Class 1 Measurements Measurement One measurement every foot 100% areal coverage, Class 1 Spacing H 6.62E+08 Co 4.38E+08 Ni 1.12E+010 Operational DCGLs for Unit 1 In-DCGLs Sr 3.98E+06 Core Sump Discharge Embedded Pipe Cs-134 - 8.40E+07 (P125), (LTP Chapter 5, Table 5-12)
Cs-137 - 1.10E+08 Eu-152 - 1.02E+09 Eu-154 - 8.88E+08 Gross Gamma DCGL adjusted for HTD ROC Analysis LTP 5.7.1.9 HTD based on the isotopic mixture Measurement
>Operational DCGLW (LTP Chapter 5, Table 5-25)
Investigation Level Scan Survey Area N/A LTP 5.7.1.9 Coverage replicate measurements will be QC performed on 5% of the static QAPP measurement locations
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
- 6. SURVEY IMPLEMENTATION Survey instructions for this FSS were incorporated into and performed in accordance with FSS Sample Plan #S1-01111-AF, which was developed in accordance with ZionSolutions procedure ZS-LT-300-001-001, Final Status Survey Package Development. The FSS unit was inspected and controlled in accordance with ZionSolutions procedure ZS-LT-300-001-003, Isolation and Control for Final Status Survey (Reference 10).
The approach used for the radiological survey of the interior surfaces of the P125 piping involved the insertion of a Ludlum Model 44-159 detector, a 1-inch x 1-inch CsI detector that was attached to the end of a fiber rod and transported through the pipe to the maximum deployment length, or to a location of drain drop. A simple push-pull methodology was used, whereby the position of the detector in the piping system could be easily determined in a reproducible manner. Footage was tabulated at 1 foot intervals while backing out of the pipe section.
A background value was also determined for the detector/instrument combination to be used prior to deployment. The background value was obtained at the location where the pre-use response check of the instrument was performed. The background value was primarily used to ensure that the detector had not become cross-contaminated by any previous use. Background was not subtracted from any measurement.
The detector was subjected to Pre and Post Operational Response Checks in accordance with procedure ZS-LT-300-001-006, Radiation Surveys of Pipe Interiors Using Sodium/Cesium Iodide Detectors (Reference 11). The Daily Operational Response Check compared the background response and the response to check sources ranges established for normal background and detector source response to ensure that the detector was working properly.
Surveys of the Unit 1 In-Core Sump Discharge Pipe (P125) were performed on Dec. 07, 2017. The survey was completed in 1 day. The piping was accessed on the 565 foot elevation of Unit 1 Containment through the pipe opening at the top of the ladder going under-vessel. The SeeSnakeTM camera was inserted 22 feet into the pipe. Because the entire length of the pipe was not accessible due to a 90 degree elbow, 22 measurements were taken at 1 foot intervals to obtain sufficient readings to achieve 100% areal coverage of the accessible internal surfaces of the pipe. Table 6 summarizes the data collected:
Table 6 - Survey Data Collected Length # of measurements Pipe run Comment surveyed taken P125 22 feet 22 3 QC readings taken
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
The instrument and detector used for this survey are presented in Table 7. The instrument and detector were verified to be properly calibrated prior to use.
Table 7 - Instrument and detector Instrument/Detector Calibration Due Serial #
Type Date Ludlum 2350-1 304713 04/12/18 Ludlum 44-159 PR327895 04/12/18 Daily prior to use (Pre-Test) and daily upon completion of surveys (Post-Test), response checks were performed in accordance with procedure ZS-LT-300-001-006 for each detector and data logger pairing. In addition, all instruments and detectors were physically inspected for mechanical damage as part of the response check process. During the FSS, no instances were encountered where an instrument and/or detector failed a Pre or Post response check or were found to be physically damaged during the inspection.
- 7. SURVEY RESULTS After completion of the FSS measurements in the pipe, the sample plan was reviewed to confirm the completeness of the survey and the survey data was validated in accordance with procedure ZS-LT-300-001-004, Final Status Survey Data Assessment (Reference 12). Data processing includes converting measurement data into reporting units, validating instrument applicability and sensitivity, calculating relevant statistical quantities, and verification that all DQO have been met. In accordance with the procedure, a preliminary Data Assessment was prepared.
The primary gamma emitting ROC for the FSS of the Unit 1 In-Core Sump Discharge Pipe (P125) FSS unit are Co-60, Cs-134, Eu-152, Eu-154 and Cs-137. H-3, Ni-63 and Sr-90 are also ROC for the Unit 1 In-Core Sump Discharge Pipe P125. Ni-63 is inferred from the measured concentration of Co-60, while Sr-90 and H-3 are inferred from the measured concentration of Cs-137.
Twenty-two (21) measurements were < 1.0 OpSOF. The mean of the OpSOF for all 22 samples was 0.1044. One measurement exceeded the exceeded the OpDCGLEP but was less than the BcDCGLEP. The SOF (based on the OpDCGL) for a systematic or a judgmental measurement/sample(s) may exceed one without remediation as long as the survey unit passes the Sign Test and, the mean SOF (based on the Operational DCGL) for the survey unit does not exceed one. Once the survey data set passes the Sign Test (using OpDCGLs), the mean radionuclide activity (pCi/m2) for each ROC from systematic measurements along with any identified elevated areas from systematic and judgmental samples will be used with the BcDCGLs to perform a SOF calculation for each surface
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
FSS unit in a basement in accordance with the following equation. The mean SOF for the survey unit will then be adjusted by adding the SOF from the elevated areas to the mean to account for the additional dose attributed to the elevated areas.
Equation 5 where:
SOFB = SOF for structural surface survey unit within a Basement using BcDCGLs Mean ConcB ROCi = Mean concentration for the systematic measurements taken during the FSS of structural surface in survey unit for each ROCi Base Case DCGLB ROCi = BcDCGL for structural surfaces (DCGLB) for each ROCi Elev ConcB ROCi = Concentration for ROCi in any identified elevated area (systematic or judgmental)
SAElev = surface area of the elevated area SASU = adjusted surface area of FSS unit for DCGL calculation The surface area of the accessible portion of the pipe (SASU) is 0.86 m2. The surface area of the elevated areas is 0.036 m2. The adjustment made to the mean SOF due to the one elevated measurement is 0.0193.
The activity in this pipe must also compared to the OpDCGLB for the building in which it resides. According to Table 5-20 of the LTP, the Unit 1 In-Core Sump Discharge Pipe (P125) will be included with the Unit 1 Containment. The results of this comparison show that 13 measurements were >SOF of 1 when compared to the OpDCGL B for the Unit 1 Containment Building. The pipe was grouted accordingly.
The data collected passed the Sign Test. The result of the Sign Test is provided in Attachment 3.
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
Table 8 - Unit 1 Incore Sump Discharge Pipe (P125)- Statistical Summary Mean Max Min Standard Base Case Nuclide Radionuclide (1) Conc. Conc. Conc. Deviation DCGL EP Mean SOF 2 2 2 2 2 (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m ) (pCi/m ) (BcDCGLEP)
H-3 3.21E+07 5.12E+08 2.94E+06 1.08E+08 8.28E+09 0.0039 Co-60 1.26E+06 2.01E+07 1.16E+05 4.26E+06 5.47E+09 0.0002 Ni-63 5.57E+08 8.90E+09 5.12E+07 1.88E+09 1.40E+11 0.0040 Sr-90 3.83E+05 6.11E+06 3.51E+04 1.29E+06 4.98E+07 0.0077 Cs-134 2.67E+03 4.26E+04 2.45E+02 9.02E+03 1.05E+09 0.0000 Cs-137 1.82E+07 2.91E+08 1.67E+06 6.15E+07 1.37E+09 0.0133 Eu-152 1.18E+05 1.88E+06 1.08E+04 3.97E+05 1.28E+10 0.0000 Eu-154 1.60E+04 2.56E+05 1.47E+03 5.41E+04 1.11E+10 0.0000 (1) Concentrations for H-3, Ni-63 and Sr-90 are inferred Mean SOF 0.0291 The SOF adjustment for the elevated measurement equals 0.0193. This value is then added to the mean SOF for the Unit 1 In-Core Sump Discharge Pipe (P125) FSS unit of 0.0291 resulting in an adjusted total mean BcSOF for the Unit 1 In-Core Sump Discharge Pipe (P125) of 0.0484. This SOF equates to a dose of 1.209 mrem/yr. This value is the dose assigned to the survey unit based on the average of the systematic measurements adjusted for the dose contribution of elevated areas.
- 8. QUALITY CONTROL In compliance with ZS-LT-01, replicate measurements were performed on 5% of the survey locations chosen at random. Three (3) replicate measurements were taken. Using the acceptance criteria specified ZS-LT-01, Quality Assurance Project Plan (QAPP) for Characterization and Final Status Survey, there was acceptable agreement between the replicate readings and the original readings. Refer to Attachment 4 for quality control analysis results.
- 9. INVESTIGATIONS AND RESULTS No investigations were required or performed.
- 10. REMEDIATION AND RESULTS No remediation was performed in this pipe.
- 11. CHANGES FROM THE SURVEY PLAN Only 22 feet of the piping was accessible for survey. Measurements were taken at 1 foot intervals in the pipe to achieve 100% coverage of accessible internal surfaces.
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
The survey instructions called for a 44-157 detector to be used for the survey. This was a typo error in the sample plan the smaller 44-159 detector was used.
- 12. DATA QUALITY ASSESSMENT (DQA)
In accordance with procedure ZS-LT-300-001-004, the DQOs, sample design, and data were reviewed for completeness, accuracy, and consistency. Documentation was complete and legible. The FSS unit was properly classified as Class 1. All measurement results were individually reviewed and validated. The number of measurements was sufficient to meet the requirement of 100% areal coverage of accessible surfaces. The instrumentation used to perform the FSS was in calibration, capable of detecting the activity with an adequate MDC and successfully response checked prior to and following use. An adequate number of replicate measurements were taken and the results meet the acceptance criteria as specified in the QAPP.
The data for Gross Gamma Activity is represented graphically through a frequency plot and a quantile plot. All graphical representations are provided in Attachment 5.
- 13. ANOMALIES No anomalies were observed during the performance or analyses of the survey.
- 14. CONCLUSION Twenty-two (22) static measurements were taken in the Unit 1 In-Core Sump Discharge Pipe (P125), at 1-foot intervals. The accessible length of pipe was 22 feet; therefore 100%
areal survey coverage was achieved.
Twenty-two (21) measurements were < 1.0 OpSOF. The mean of the OpSOF for all 22 samples was 0.1044. One measurement exceeded the exceeded the OpDCGLEP but was less than the BcDCGLEP. The SOF adjustment for the elevated measurement equals 0.0193. This value is then added to the mean BcSOF for the Unit 1 In-Core Sump Discharge Pipe (P125) FSS unit of 0.0291 resulting in an adjusted total SOF for the Unit 1 In-Core Sump Discharge Pipe (P125) of 0.0484. This SOF equates to a dose of 1.209 mrem/yr.
The Sign Test was passed, and the Null Hypothesis was rejected.
The conclusion of this Release Record is that Survey Unit #S1-01111 passes FSS.
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125) 15 REFERENCES
- 1. ZionSolutions procedure ZS-LT-300-001-005, Final Status Survey Data Reporting
- 2. Zion Station Restoration Project License Termination Plan (LTP)
- 3. ZionSolutions procedure ZS-LT-300-001-001, Final Status Survey Package Development
- 4. NUREG-1575, Revision 1, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)
- 5. ZionSolutions procedure ZS-LT-300-001-002, Survey Unit Classification
- 6. Zion Station Historical Site Assessment (HSA)
- 7. ZionSolutions TSD 14-016, Description of Embedded Piping, Penetrations, and Buried Pipe to Remain in Zion End State
- 8. ZionSolutions TSD 17-004, Operational Derived Concentration Guideline Levels for Final Status Survey
- 9. ZionSolutions procedure ZS-LT-01, Quality Assurance Project Plan (QAPP) for Characterization and Final Status Survey
- 10. ZionSolutions procedure ZS-LT-300-001-003, Isolation and Control for Final Status Survey
- 11. ZionSolutions procedure ZS-LT-300-001-006, Radiation Surveys of Pipe Interiors Using Sodium/Cesium Iodide Detectors
- 12. ZionSolutions procedure ZS-LT-300-001-004, Final Status Survey Data Assessment
- 16. ATTACHMENTS Attachment 1 - Figure and Maps Attachment 2 - Sample Data Attachment 3 - Sign Test Attachment 4 - QC Data Attachment 5 - Graphical Presentations
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
ATTACHMENT 1 - FIGURES AND MAPS
FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
ATTACHMENT 2 - SAMPLE DATA
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
ATTACHMENT 3 - SIGN TEST
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
ATTACHMENT 4 - QC DATA
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
Unit 1 In-Core Sump Discharge Pipe (P125) - QC Agreement Duplicate Sample Assessment Form Survey Unit #: 01111A Survey Unit # P125 Survey Unit Name: U1 In Core Sump Discharge Pipe Sample Plan#: S101111A-F Sample
Description:
Comparison of replicate measurements collected from measurement location #s 6, 12 and 20. The standard measurements were S1-01111A-FSSM-006-GD, S1-01111A-FSSM-012-GD and S1-01111A-FSSM-020-GD. The comparison measurments were S1-01111A-FQSM-006-GD, S1-01111A-FQSM-012-GD and S1-01111A-FQSM-020-GD.
Standard Measurement Duplicate Activity Activity Acceptable
+20% -20%
ID Value ID Value (Y/N)
(pCi/m 2 ) (pCi/m 2 ) (pCi/m 2 ) (pCi/m 2 )
S1-01111A-FSSM-006-GD 3.45E+06 4.13E+06 2.76E+06 S1-01111A-FQSM-006-GD 3.32E+06 Y S1-01111A-FSSM-012-GD 2.10E+06 2.52E+06 1.68E+06 S1-01111A-FQSM-012-GD 2.13E+06 Y S1-01111A-FSSM-020-GD 2.92E+06 3.50E+06 2.33E+06 S1-01111A-FQSM-020-GD 4.17E+06 Y Comments/Corrective Actions: The 1st two replicate measurement The acceptance criteria for replicate static measurements results (S1-01111A-FQSM-006-GD and S1-01111A-FQSM-012- and scan surveys is that the same conclusion is reached GD) are in acceptable agreement (within + 20%). The 3rd replicate for each measurement. This is defined as + 20% of the measurement S1-01111A-FSSM-020 result is outside of the standard acceptance range (+30%). This is expectedly due to the detector not being positioned exactly over the original location resulting in the higher value. In accordance with section 4.1.2 of the QAPP, a replicate measurement is in agreement if, based on the professional judgment of the Radiological Engineer, that the same conclusion is reached for the replicate measurement location as with the standard. In the case of S1-01111A-FQSM-020-GD, this is true. No further investigation is necessary.
Performed by: Date: Reviewed by: Date:
9/18/2018 9/18/2018
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
ATTACHMENT 5 - GRAPHICAL PRESENTATIONS
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
QUANTILE PLOT FOR GROSS GAMMA ACTIVITY Survey Unit: S101111A Survey Unit Name: Unit 1-In-Core Sump Drain Pipe (No. P125)
Mean: 1.96E+07 pCi/m2 Quantile Plot for Gross Gamma Activity 3.50E+08 3.00E+08 2.50E+08 2.00E+08 1.50E+08 1.00E+08 5.00E+07 0.00E+00 0% 20% 40% 60% 80% 100% 120%
Percentage Point Gross Gamma Rank Percent 15 1.80E+06 22 0%
16 1.83E+06 21 5%
14 2.07E+06 20 10%
13 2.10E+06 19 14%
17 2.23E+06 18 19%
20 2.36E+06 17 24%
12 2.38E+06 16 29%
18 2.45E+06 15 33%
10 2.55E+06 14 38%
11 2.84E+06 13 43%
19 2.86E+06 12 48%
21 2.92E+06 11 52%
9 2.96E+06 10 57%
8 3.28E+06 9 62%
7 3.45E+06 8 67%
6 3.45E+06 7 71%
5 4.36E+06 6 76%
4 4.45E+06 5 81%
3 9.98E+06 4 86%
22 1.07E+07 3 90%
2 4.74E+07 2 95%
1 3.13E+08 1 100%
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FSS RELEASE RECORD U1 CONTAINMENT IN CORE SUMP DISCHARGE PIPE SURVEY UNIT 01111(P125)
HISTOGRAM FOR GROSS GAMMA ACTIVITY Survey Unit: S101111A Survey Unit Name: Unit 1 In-Core Sump Drain Pipe (P125)
Mean: 1.96E+07 pCi/m2 Median: 2.89E+06 pCi/m2 ST DEV: 6.62E+07 Skew: 4.54E+00 Histogram 25 21 20 15 10 Frequency 5
1 0 0 0 0 0
5.37E+07 5.37E+07 5.37E+07 5.37E+07 1.06E+08 More Bin pCi/m2 Bin Frequency 5.37E+07 21 5.37E+07 0 5.37E+07 0 5.37E+07 0 1.06E+08 0 More 1
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