ML25328A176

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Us Dept of Transportation - Nuclear Ship Savannah, Survey Unit Release Record Survey Unit SYS-117-01 Neutron Shield Tank, Retained Walls
ML25328A176
Person / Time
Site: NS Savannah
Issue date: 11/20/2025
From: Roberson D
US Dept of Transportation, Maritime Admin, Nuclear Ship Support Services
To:
Office of Nuclear Reactor Regulation
References
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U.S. Department of Transportation Maritime Administration Office of Ship Operations Nuclear Ship SAVANNAH Survey Unit Release Record Survey Unit SYS-117-01 Neutron Shield Tank, Retained Walls Approved: a-~~-- ef7,3/:..zr Senior Technical Advisor Date Prepared by:

Nuclear Ship Support Services, LLC

S AVANNAH Technical Staff Survey Unit Release Record PREPARED BY/ DATE:

PEER REVIEW/ DATE:

DECOMMISSIONING PROGRAM MANAGER REVIEW /DATE:

INDEPENDENT REVIEW/

DATE:

FSS MANAGER REVIEW/ DATE:

LICENSING and COMPLIANCE MANAGER REVIEW /DATE:

SAFETY REVIEW COMMITTEE SUBMITTED/ APPROVED LICENSE TERMINATION PLAN MANAGER REVIEW/ DATE:

Survey Unit SYS-117-01 Neutron Shield Tank, Retained walls D. Roberson Digitally signed by D. Roberson Date: 2025.03.12 09:01 :15 -05'00' Douglas Roberson Date Pete Hollenbeck DigitallysignedbyPeteHollenbeck

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Pete Hollenbeck, CHP Date Soeuth Caleb Soeun Digitally signed by Soeuth Caleb Soeun Date: 2025.03.17 13:01 :41 -04'00' Soeuth C. Soeun Date James Reese CHP Digitally signed by James Reese, 1

1 CHP RRPT RRPT Dat~: 2025.03.18 09:26:00-07'00' James Reese Date Dan *, e I R M *,ha 1

  • 1 k Digitally signed by Daniel R. Mihalik Date: 2025.03.28 18:56:54 -04'00' Daniel Mihalik John Osborne John Osborne 3/19/2025 Submitted Eric Darois Date Digitally signed by: John Osborne LCM DN: CN = John Osborne LCM email LCM

= jmosborne@nsss.llc C = AD Date: 2025.04.29 15:52:25 -05'00' Date 3/28/2025 Approved 9/2/2025 Date Page 2 of 31

S AVANNAH Technical Staff Survey Unit Release Record TABLE OF CONTENTS

1.

EXECUTIVE

SUMMARY

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

2.

SURVEY UNIT DESCRIPTION.......................................................................................... 6

3.

CLASSIFICATION BASIS................................................................................................... 6

4.

DATA QUALITY OBJECTIVES......................................................................................... 7

5.

SURVEY DESIGN............................................................................................................... 10

6.

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

7.

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

8.

QUALITY CONTROL........................................................................................................ 17

9.

INVESTIGATIONS AND RESULTS................................................................................ 17

10. REMEDIATION AND RESULTS...................................................................................... 17
11. CHANGES FROM THE FINAL STATUS SURVEY PACKAGE................................. 17
12. DATA QUALITY ASSESSMENT...................................................................................... 17
13. ANOMALIES....................................................................................................................... 18
14. CONCLUSIONS................................................................................................................... 18
15. REFERENCES..................................................................................................................... 18
16. ATTACHMENTS................................................................................................................. 19 Survey Unit SYS-117-0 I Page 3 of3 I Neutron Shield Tank, Retained walls

SAVANNAH Technical Staff Survey Unit Release Record LIST OF TABLES Table 4 Radionuclide Fractions and Normalized Fractions............................................... 8 Table 4 15 mrem/y DCGLs for ROC and Ni-63.................................................................. 8 Table 4 Re-normalized Co-60 and Cs-137 Fractions.......................................................... 9 Table 4 Operational DCGLs................................................................................................ 10 Table 5 SYS-117-01 Systematic Measurement Designations............................................ 11 Table 5 Scanning Coverage................................................................................................. 12 Table 5 Investigation Levels................................................................................................ 12 Table 7 Summary of Systematic, Judgmental, and QC Static Measurements................ 15 Table 7 Basic Statistical Properties of Static Measurement Population.......................... 15 Table 7 Scan Measurement Summary................................................................................ 16 Survey Unit SYS-I 17-01 Page 4 of31 Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record LIST OF ACRONYMS AND ABBREVIATIONS ALARA As Low As Reasonably Achievable CR Contractor Report DQO Data Quality Objective DCGL Derived Concentration Guideline Level ETD Easy-to-Detect FSS Final Status Survey HTD Hard-to-Detect IC Insignificant Dose Contributors LBGR Lower Bound of the Gray Region LTP License Termination Plan MARAD Maritime Administration MARLAP Multi-Agency Radiological Laboratory Analytical Protocols MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDC Minimum Detectable Concentration NSS Nuclear Ship S AVANNAH NST Neutron Shield Tank QC Quality Control ROC Radionuclides of Concern TEDE Total Effective Dose Equivalent UBGR Upper Bound of the Gray Region YSP Visual Sample Plan Survey Unit SYS-117-01 Neutron Shield Tank, Retained walls Page 5 of3 l

SAVANNAH Technical Staff Survey Unit Release Record

1.

EXECUTIVE

SUMMARY

1 - --- h rt This Survey Unit Release Record for survey unit SYS-I I 7-01, Neutron Shield Tank [NST],

Retained Walls, has been generated in accordance with Maritime Administration (MARAD) procedure STS-005-035, Preparation of Survey Unit Release Records and FSS Final Reports, Reference (a) and satisfies the requirements of Section 5.10 of the Nuclear Ship SAVANNAH (NSS) License Termination Plan [LTP], STS-004-003, Revision l, Reference (b ).

A Final Status Survey (FSS) survey package for this survey unit was developed in accordance with MARAD procedure STS-005-030, Preparation of Final Status Survey Packages, Reference (c), the NSS LTP, and with guidance from NUREG-1575, Revision I, Multi-Agency Radiation Survey and Site Investigation Manual (MARS SIM), Reference (d).

This survey unit has a MARSSIM classification of Impacted. A survey package was designed based upon the use of the Sign Test as the nonparametric statistical test for compliance. Both the Type I (a) and Type II(~) decision error rates were set at 0.05. As a systematic measurement population, fifteen (15) static beta measurements were acquired from the survey unit. In addition, two (2) judgmental static beta measurements were acquired. Surface scanning was performed on approximately 100% of the total surface area in the survey unit. The data assessment results for survey unit SYS-117-0 l show that the maximum gross activity concentration among all the final systematic and judgmental measurements is equal to 6,261.95 dpm/100 cm 2, which is 12.0% of the operational Derived Concentration Guideline Level (DCGLw) value of 52,300 dpm/100 cm2.

Therefore, the null hypothesis of the Sign Test is rejected, and survey unit SYS-117-0 I is acceptable for unrestricted use. The mean gross activity concentration among all the final systematic and judgmental measurements is equal to I, 716.89 dpm/100 cm2, which is 2.5%

ofthe 15 mrem/y gross activity DCGLw of69,700 dpm/100 cm2. The mean gross activity concentration is equal to 0.37 mrem/y for the survey unit.

2.

SURVEY UNIT DESCRIPTION SYS-117-01 is an impacted systems survey unit. The NST was a primary shield filled with water that surrounded the reactor vessel. The survey unit consists of interior and exterior walls. The total surface area is approximately I 48 square meters (148 m2), based upon Computer Aided Design drawings. Refer to Attachment 1 of this report for figures and maps depicting survey unit SYS-117-01.

3.

CLASSIFICATION BASIS The NST scoping survey #042020231100 performed on 04/20/23, shows the system to be up to twice background. Based upon review of the historical information, the results of the characterization survey data, and completion of a final Survey Unit Classification Survey Unit SYS-117-01 Page 6 of3 l Neutron Shield Tank, Retained walls

SAVANNA H Technical Staff Survey Unit Release Record Worksheet, the correct final classification of survey unit SYS-117-01 is an Impacted system.

4.

DATA QUALITY OBJECTIVES FSS planning and design relies on a properly executed Data Quality Objective (DQO) process to ensure, through compliance with explicitly defined inputs and boundaries, that the primary objective of the survey is satisfied. The DQO process is described in the NSS LTP. The appropriate design for a given survey was developed using the DQO process as outlined in STS-05-030, Reference (c).

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 package, 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 SYS-117-0 I did not exceed the release criteria specified in the L TP and that the potential dose from residual radioactivity is As Low As Reasonably Achievable (ALARA).

MARAD Contractor Report (CR)-139, Calculations to Support NSS Surface Contamination DCGLs, Reference (e) established the basis for an initial suite of potential Radionuclides of Concern (ROC) for decommissioning. Insignificant dose contributors (IC) were determined consistent with the guidance contained in Section 3.3 of NUREG-

1757, Volume 2,

Revision 1,

Consolidated Decommissioning Guidance Characterization, Survey, and Determination of Radiological Criteria, Reference (t). In all analyses, Cs-137 and Co-60 contribute nearly I 00% of the total dose. The remaining radionuclides were designated as IC. Because Ni-63 comprises approximately 90% of the total activity, it is accounted for as a surrogate to Co-60. Therefore, the final ROCs for final status surveys are Cs-137 and Co-60surrogate.

LTP Chapter 6, Section 6.13 discusses the process used to derive the ROC for the decommissioning of the NSS, including the elimination of insignificant dose contributors from the initial suite. Table 4-1 on the next page presents the initial suite of ROC for the decommissioning of the NSS, and the normalized mixture fractions based on the radionuclide mixture.

Survey Unit SYS-117-01 Page 7 of3 I Neutron Shield Tank, Retained walls

SAVANNAH Technical Staff Survey Unit Release Record Table 4 Radionuclide Fractions and Normalized Fractions Normalized Sum of Sum of Only Co, Ni Nuclide Fractions Fractions and Cs C-14 3.37E-02 5.61 E-03 Co-60 9.78E-02 l.63E-02 l.63E-02 Ni-63 5.40E+00 9.00E-01 9.00E-01 Sr-90 9.22E-06 l.54E-06 Tc-99 1.27E-04 2.11 E-05 Ag-108m 8.30E-04 l.38E-04 Cs-137 4.57E-0l 7.61 E-02 7.61 E-02 H-3 1.93E-03 3.21 E-04 Fe-55 8.l0E-03 l.35E-03 Am-241 5.79E-07 9.66E-08 Pu-239/240 4.81E-07 8.0lE-08 Totals 6.00E+00 l.00E+00 9.93E-01 h st Each radionuclide-specific DCGLw is equivalent to the level of residual radioactivity (above background levels) that could, when considered independently, result in a Total Effective Dose Equivalent (TEDE) of 15 mrem/yr to an Average Member of the Critical Group. Table 4-2 presents the 15 mrem/y DCGLw for Co-60, Ni-63 and Cs-137 from Chapter 6 of the L TP.

Table 4 15 mrem/y DCGLs for ROC and Ni-63 Radionuclide DCGLw (dpm/100cm2)

Co-60 2.37E+04 Ni-63 2.53E+08 Cs-137 1.20E+05 Nickel-63 is a Hard-to-Detect (HTD) radionuclide. To account for Ni-63, the Easy-to-Detect (ETD) radionuclide Co-60 will be used as a surrogate.

The surrogate DCGL is computed as:

DCGL DCGLETD X DCGLnrv surrogate =

(f HTD:ETDXDCGLETD)+ DCGLHTD Where:

DCGLETD

==

the DCGL for the easy-to-detect radionuclide DCGLHTD==

the DCGL for the hard-to-detect radionuclide Survey Unit SYS-117-0 I Neutron Shield Tank, Retained walls Equation 1 Page 8 of3 I

SAVANNAH Technical Staff Survey Unit Release Record FHTD:ETD the activity ratio of the hard-to-detect radionuclide to the easy-to-detect radionuclide Using the data in Table 4-1, the Ni-63/Co-60 ratio equals 55.3. Solving Equation 1 using the DCGLs for Co-60 and Ni-63 in Table 4-2 and the Ni-63/Co-60 ratio of 55.3 is shown below.

G 2.53E+08 2

DC Lco-60 surrogate= 2.37E + 04 X (

)

= 2.36E+04 dpm/100 cm 55.3 X 2.37E+04 +2.53E+08 A gross activity DCGLw has been established, based on the representative radionuclide mix, as follows:

Where:

fn n

DCGLn 1

Gross Activity DCGLw = ti 12 fn DCGL1 + DCGL2 +** DCGLn

=

fraction of the total activity contributed by radionuclide n the number of radionuclides

=

DCGL for the ROC Equation 2 Of the three radionuclides, only Co-60 and Cs-137 can be detected by gross activity measurements. The normalized fractions for both radionuclides in Table 4-1 have to be re-normalized for use in Equation 2. Table 4-3 presents the re-normalized fractions for each radionuclide.

Table 4 Re-normalized Co-60 and Cs-137 Fractions Normalized Only Co-60 Re-sum of and Cs-137 normalized Nuclide fractions Fractions Fractions C-14 5.61 E-03 Co-60 1.63E-02 1.63E-02 1.76E-0l Ni-63 9.00E-01 Sr-90 1.54E-06 Tc-99 2.11 E-05 Ag-108m 1.38E-04 Cs-137 7.61 E-02 7.61E-02 8.24E-01 H-3 3.21 E-04 Fe-55 l.35E-03 Am-241 9.66E-08 Pu-239/240 8.0IE-08 Totals I.00E+00 9.24E-02 I.00E+00 Survey Unit SYS-117-01 Page 9 of31 Neutron Shield Tank, Retained walls

SAVANNAH Technical Staff Survey Unit Release Record Solving Equation 2 using the re-normalized Co-60 and Cs-137 fractions and the Co-60 surrogate DCGL is shown below.

1 Gross Activity DCGLw = 1_76E-l 8_24E-l = 6.97E+04 dpm/100 cm2.

2.36E+o4 + 1.20E+os The DCGLs are reduced to a fraction of the 15 mrem/yr dose limit. The reduced DCGLs, or operational DCGLw, is then used as the DCGL for the FSS design of the survey unit (investigations levels, etc.). The operational DCGLs are set at 75% of the 15 mrem/y DCGLw. The operational DCGLs are provided in Table 4-4.

Table 4 Operational DCGLs Radionuclide Operational DCGLw (dpm/100cm2)

Co-60 l.77E+04 Cs-137 9.00E+04 Gross Activity 5.23E+04 Instrument DQOs included a verification of the ability of the survey instrument to detect the radiation(s) of interest relative to the operational DCGLw. Survey instrument response checks were required prior to issuance and after the instrument had been used. Control and accountability of survey instruments was required to ensure the quality and prevent the loss of data. STS-05-030, Reference (c) states that a Minimum Detectable Concentration (MDC) below l 0% of the DCGL is preferable and up to 50% is acceptable. Because the background is low on the NSS, the MDC for most static and scan measurements were less than 10% ofthe DCGL and in all cases the MDCs were less than 50% of the DCGL.

5.

SURVEY DESIGN The L TP specifies that the Sign Test will be used as the nonparametric statistical test for compliance with the release criteria. The number of measurements for use with the Sign Test was determined in accordance with MA RAD procedure STS-005-031, Calculation of the Number of Measurements.for Final Status Surveys, Reference (g). The relative shift for the survey unit data set is defined as shift(~), which is the Upper Boundary of the Gray Region (UBGR), or the operational DCGLw, minus the Lower Bound of the Gray Region (LBGR), divided by sigma (er), which is the standard deviation of the data set used for survey design. The optimal value for the relative shift should range between one (l) and three (3). If the relative shift is less than one (1), or greater than three (3), then the value of two (2) will be used for the relative shift.

A NST scoping survey #042020231100 was performed on 04/20/23. Twenty (20) total surface activity measurements were collected. The maximum beta activity was 1,569 Survey Unit SYS-117-01 Page 10 of3 I Neutron Shield Tank, Retained walls

SAVANNA H Technical Staff Survey Unit Release Record l - -

- d i t dpm/100 cm2. The average act1v1ty concentration and standard deviation of the measurements was 798 and 353 dpm/100 cm2, respectively. Because the activity concentration is low, the LBGR was set to half the operational DCGLw. The relative shift for survey unit SYS-117-01, is based upon the scoping survey results and was calculated as follows:

52,300-26,150 Relative Shift (il/cr) =

353

= 74 Because the calculated relative shift was greater than three (3), the value of two (2) was used as the adjusted relative shift. Both the Type I error, or a value, and the Type II error, or p value, were set at 0.05. The sample size from STS-05-031, Reference (h) that equates to the Type I and Type II error of 0.05 for use with the Sign Test is a minimum number of fixed measurements value of fifteen (15). Fifteen (15) total systematic measurements were used in the survey design for survey unit SYS-117-01.

The survey unit was designated as an Impacted system which called for judgmental measurements. However, due to decommissioning activities in the proximity of the NST in the Containment Vessel, the measurement locations were selected based on a systematic grid with a random starting point. The systematic locations of the static measurements were selected using Visual Sample Plan (VSP). lnput parameters included the use of survey unit drawings, and the systematic sampling tool set with a predetermined number of measurement locations. The systematic measurement locations were identified in the field using dimension parameters provided on the survey unit map (see Attachment I).

Table 5-1 lists the systematic measurements to be collected for FSS of survey unit SYS-117-01.

Table 5 SYS-117-01 Systematic Measurement Designations Label LX(m)

LY(m)

Surface SYS-117-01-01 5.32 1.56 Exterior Shell Port Side SYS-117-01-02

-0.67 3.30 Exterior Shell Port Side SYS-117-01-03 3.01 5.03 Exterior Shell Port Side SYS-117-01-04 1.17 0.09 Exterior Shell Port Side SYS-117-01-05 0.34 1.82 Interior Shell Port Side SYS-117-01-06

-4.26 3.56 Interior Shell Port Side SYS-117-01-07

-0.58 0.67 Interior Shell Port Side SYS-117-01-08

-2.42 2.40 Interior Shell Port Side SYS-117-01-09 5.78 4.13 Exterior Shell Starboard Side SYS-117-01-10

-1.25 1.24 Exterior Shell Starboard Side SYS-117-01-11 2.44 2.98 Exterior Shell Starboard Side SYS-117-01-12 0.59 4.71 Exterior Shell Starboard Side SYS-117-01-13

-0.23 0.28 Interior Shell Starboard Side SYS-117-01-14

-4.84 2.01 Interior Shell Starboard Side SYS-117-01-15

-1.15 3.75 Interior Shell Starboard Side Survey Unit SYS-117-0 I Page 11 of31 Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record The implementation of Quality Control (QC) measures is referenced in L TP Chapter 5, Section 5.11. A randomly chosen replicate measurement was specified in the survey package. This measurement was to be collected by either a different technician or by a different instrument. Location SYS-117-01-02 was chosen for the replicate measurement.

In addition, the survey package also specified to perform QC operability checks of field instruments both prior to and after collection of the measurements.

The survey package also specified collection of two (2) judgmental measurements to augment the systematic measurements. The locations of these two measurements were to be determined by the technicians or the field supervisor. Those two judgmental measurements are identified as SYS-117-01-16-J, interior shell starboard side and SYS-117-01-17-J, exterior shell port side. Those locations are documented on the field forms.

For this Impacted system survey unit, the "Scanning Coverage" are those levels specified in L TP Chapter 5, Table 5-3, and are reproduced below in Table 5-2.

Table 5 Scanning Coverage Classification Required Scanning Coverage Fraction Systems and Components Judgmental For survey unit SYS-117-01, twelve scan areas were established. The survey package stated to scan 100% of the accessible area in each scan area SA-01 through SA-12. An estimated I 00% of the accessible surface area in SYS-117-0 I was to be scanned. Refer to for figures and maps depicting the measurement and scan locations in survey unit SYS-117-01.

For this Impacted systems survey unit, the "Investigation Levels" for direct and scanning measurement results are those levels specified in L TP Chapter 5, Table 5-2, and are reproduced below in Table 5-3.

Table 5 Investigation Levels Classification Direct Investigation Levels Scan Investigation Levels Systems and

> Operational DCGLw

> Operational DCGLw Components These investigation levels were specified in the survey package.

An additional action level was specified in the survey package. If the technician observed a count rate of2,500 cpm when scanning, approximately one-half of the investigation level, they were to stop scanning, backup and rescan the elevated location again to see if the count rate was observed again. If observed again, an additional static measurement would be collected. If not, they would continue scanning.

Survey Unit SYS-117-01 Page 12 of31 Neutron Shield Tank, Retained walls

SAl'ANNAH Technical Staff Survey Unit Release Record

6.

SURVEY IMPLEMENTATION For survey unit SYS-117-0 I, compliance with the unrestricted use criteria was demonstrated through a combination of surface scanning and surface static measurements with a Ludlum Model 43-93 ZnS detector connected to a Ludlum Model 3002 meter operating in beta mode. Additionally, a Ludlum 43-37 large area gas proportional detector connected to a Ludlum Model 3002 meter was utilized in the beta mode for surface scanning.

Prior to performing the survey, a walkdown of the survey unit was performed per MARAD procedure STS-005-032, Survey Unit Turnover and Control, Reference (h). No conditions prohibited the proper collection of static and scan measurements.

FSS field activities were conducted under the approved FSS Package Number NSS-FSSP-SYS-117-01-00-00, which included DQOs, survey design, detailed F instructions, survey maps and survey forms. FSS field activities were projected to take three (3) working days to complete. A daily briefing was conducted to discuss the expectations for job performance and to review safety aspects of the job. An FSS package "Field Log" was used to document field activities and other information pertaining to the performance of the FSS.

The FSS field activities took three (3) days to complete and were performed on July 17, 2024, July 18,2024, and July 22, 2024, except for a static measurement collected on July 25, 2024, in SA-10.

An ambient background count rate was collected by taking a I-minute static measurement, while maintaining the detector waist high. This value was used to calculate the MDC for scanning and static measurements.

The fifteen (15) systematic static measurement locations were marked based on the dimensions provided on the survey map. Two (2) judgmental measurement locations were selected and marked as per the sample plan. A I-minute static measurement was acquired at each location with the detector in contact with the surface.

All planned scan areas, SA-01 through SA-12, were scanned. Approximately 100% of the total surface area was scanned. The actual total scan area exceeds the scan coverage requirements for Systems and Components as shown in L TP Table 5-3 and reproduced in Table 5-2 of this release record. Scanning was performed with the detector held approximately 0.75 inches from the surface while moving at a speed of one detector width per second.

The implementation of survey specific QC measures included the collection of one (I) replicate static measurement. The random location of the replicate measurement was SYS-117-01-02 and identified as SYS-117-01-02-O. That measurement was collected with a different instrument, but the same make and model used for the original measurement.

Survey Unit SYS-117-01 Page 13 of3 I Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record l - - --- bri The instruments used for this survey were satisfactorily checked prior to and after performing the survey.

7.

SURVEY RESULTS The efficiencies used to convert count rates to activity are weighted efficiencies in which the Tc-99 (Co-60 surrogate) and Cs-137 efficiencies are weighted by the fraction Co-60 and Cs-137 comprise the NSS fingerprint. This is documented in CR-164, Reference (i).

For example, (derived from NUREG-1507) if the 41t contact Tc-99 efficiency is 0.1002 c/d and the 41t Cs-137 contact efficiency is 0.1868 c/d, the weighted contact efficiency is shown below.

Weighted efficiency ( c/d) = (0.1002) (0.176) + (0.1868) (0.824) = 0. 1716 c/d Copies of the instrument calibration records are presented in Attachment 2.

The ambient background count rate from a I-minute count was 74 cpm. Rounding up the count rate to 75 cpm, using the contact detector weighted efficiency of 0.1530 c/d for unpainted surfaces or the weighted efficiency of 0.0858 for painted surfaces and using L TP Equation 5-6 (derived from NUREG-1507), in which the count time and background count times are equal, results in an MDC for I-minute static measurement equal to 283 dpm/100 cm2 on unpainted surfaces and 504 dpm/100 cm2 on painted surfaces. These values do not exceed 1 % of the operational or gross activity DCGLw.

Table 7-I, on the next page, presents the activity concentration for all final static measurements. The remainder of this page left blank intentionally.

Survey Unit SYS-117-01 Page 14 of3 I Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record Table 7 Summary of Systematic, Judgmental, and QC Static Measurements Activity Concentration Measurement ID (dpm/100 cm2)

SYS-117-01-01 1107.79 SYS-117-01-02 1096.13 SYS-117-01-03 1224.40 SYS-117-01-04 1131.12 SYS-117-01-05 490.23 SYS-117-01-06 444.48 SYS-117-01-07 405.26 SYS-I 17-01-08 320.28 SYS-117-01-09 967.86 SYS-117-01-10 1247.73 SYS-117-01-11 5608.94 SYS-117-01-12 2122.30 SYS-117-01-13 496.77 SYS-117-01-14 379.11 SYS-117-01-15 418.33 SYS-I 17-01-16-J 5464.45 SYS-117-01-17-J 6261.95 SYS-117-0 I D 824.25 The raw static data with detector efficiencies are presented in Attachment 3.

t Table 7-2 presents the basic statistical properties of all the final static measurement population, without the duplicate measurement.

Table 7 Basic Statistical Properties of Static Measurement Population Parameter Value Units Minimum Measurement 320.28 dpm/100 cm2 Maximum Measurement 6261.95 dpm/100 cm2 Mean 1716.89 dpm/100 cm2 Median 1096.13 dpm/100 cm2 Standard Deviation 1998.38 dpm/100 cm2 Coefficient of Variation 1.16 unitless Residual activity dose rate 0.37 mrem/y The mean activity from static measurements was divided by the gross activity DCGLw to derive a mean fraction. The mean fraction was then multiplied by 15 mrem/yr to derive the dose attributed to the survey unit. For survey unit SYS-117-01, the calculated dose from residual activity is 0.37 mrem/yr.

The scan MDC for the Ludlum 43-93 detector was calculated using the same rounded count rate of 75 cpm, the detector weighted efficiency on unpainted surfaces of 0.1128 c/d and a weighted efficiency on painted surfaces of0.0632 c/d at a distance of0.75 inches and using Survey Unit SYS-117-01 Page 15 of3 I Neutron Shield Tank, Retained walls

S AVANNA H Technical Staff Survey Unit Release Record LTP Equation 5-8 (derived from NUREG-1507). The elevated area was assumed to be a 100 cm2 circular source. The detector width is 3.6 inches, and thus the detector speed is 3.6 in/second. With these parameters, the resulting observation interval is 1.234 seconds. The resulting MDC for scanning unpainted surfaces is 1,045 dpm/100 cm2 and the scan MDC for painted surfaces is 1,865 dpm/100 cm2. The most conservative value of 1,865 dpm/100 cm2 is 3.6% of the operational DCGLw and 2.7% of the gross activity DCGLw.

The scan MDC for the Ludlum 43-37 detector was calculated using the count rate of 150 cpm, the detector weighted efficiency on unpainted surfaces of 0.1506 c/d and a weighted efficiency on painted surfaces of 0.0878 c/d at a distance of 0.75 inches and using LTP Equation 5-8 (derived from NUREG-1507). The elevated area was assumed to be a I 00 cm2 circular source. The detector width is 6.25 inches, and thus the detector speed is 6.25 in/second. With these parameters, the resulting observation interval is 0.71 lseconds. The resulting MDC for scanning unpainted surfaces is 249.7 dpm/100 cm2 and the scan MDC for painted surfaces is 428.3 dpm/100 cm 2. The most conservative value of 428.3 dpm/100 cm2 is 0.8% of the operational DCGLw and 0.6% of the gross activity DCGLw.

Table 7-3 presents activity concentrations for all scan measurements.

Table 7 Scan Measurement S ummary Low to High Range Average Scan ID (dpm/100 cm2) d m/100 cm 2)

SA-01 231.91 - 1591.56 911.74 SA-02 90.95 - 312.63 201.79 SA-03 59.12 - 1064.28 561.70 SA-04 90.95 - I 064.28 577.62 SA-05 48.88 - 1623.02 835.95 SA-06 109.14-1623.02 866.08 SA-07 192.12 - 2849.34 1520.73 SA-08 128.08 - 533.67 330.88 SA-09 91.79 - 783.42 437.60 SA-10 111 - 66484.52 33297.76 SA-I I 76.85 - 3245.08 1660.96 SA-12 102.46 - 3245.08 1673.77 The raw scan data with detector efficiencies are presented in Attachment 3.

One (1) static measurement was collected on July 25, 2024, in SA-IO due to a positive indication during scanning which triggered the 2,500 cpm action level. This condition was observed when performing the preliminary data review. The follow-up static measurement SA-I 0-0 I resulted in an activity concentration of 31,368.07 dpm/100 cm2 which is below the investigation level.

Survey Unit SYS-117-01 Page 16 of31 Neutron Shield Tank, Retained walls

SAVANNAH Technical Staff Survey Unit Release Record

8.

QUALITY CONTROL 1 - - -- f rt The implementation of survey specific QC measures included the collection of one (I) replicate static measurement (SYS-117-01-02-O) for analysis. The acceptance criteria for replicate static measurements is defined by NUREG-1576, Multi-Agency Radiological Laboratory Analytical Protocols Manual (MARLAP) Volume 1, Appendix C, Section C.4.2.2 Duplicate Analyses, Reference (j). That section states that when the average of the two measurements is less than the UBGR, the control limit for the absolute difference between the two values is 4.24µMR. The required method uncertainty (µMR) is a control limit formula value that is equal to the shift divided by ten (I 0). The shift is equal to the operational DCGLw, minus one half the operational DCGLw, or 26,150 dpm/100 cm2.

Therefore, the control limit is equal to 11,087.6 dpm/100 cm2, as shown below.

Control limit= 26, 150/10*4.24 = 11,087.6 dpm/100 cm2.

The results of the evaluation of the QC measurement show agreement between the original and duplicate measurements. See Attachment 4 for the results.

9.

INVESTIGATIONS AND RESULTS No investigation levels were triggered, and no investigations were performed as the result of the analysis of the collected data.

10.

REMEDIATION AND RESULTS No radiological remedial action was performed in this survey unit as a result of the FSS.

11.

CHANGES FROM THE FINAL STATUS SURVEY PACKAGE There were no addendums or field changes to the FSS package which was developed in accordance with STS-005-030.

12.

DATA QUALITY ASSESSMENT The DQO sample design and data were reviewed in accordance with MARAD procedure STS-005-033, Final Status Survey Data Assessment and Investigation, Reference (k) completeness and consistency. Documentation was complete and legible. Scan surveys and the collection of static measurements were consistent with the DQOs and were sufficient to ensure that the survey unit was properly designated as an Impacted system.

The preliminary data review consisted ofcalculating basic statistical quantities (e.g., mean, median, standard deviation). The mean and median values of the data were well below the operational DCGLw. The survey unit data is presented graphically in a frequency plot and quantile plot presented in Attachment 6.

All fifteen systematic/unbiased measurements did not require remediation and were less than the DCGLw. Although MARSSIM states that the Sign Test need not be performed in Survey Unit SYS-I I 7-0 I Page 17 of31 Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record 1 - -- + b rt the instance that no measurements exceed the OCGLw, the test was conducted to demonstrate coherence to the statistical principles of the OQO process. The Sign Test was performed on the data and compared to the original assumptions of the OQOs. The evaluation of the Sign Test results clearly demonstrates that the survey unit passes the unrestricted use criteria, thus, the nu II hypothesis is rejected. The results of the Sign Test are presented in Attachment 5.

13.

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

14.

CONCLUSIONS

15.

(a)

(b)

(c)

(d)

(e)

(t)

(g)

(h)

(i)

Survey unit SYS-117-01 has met the OQOs of the FSS package. The survey unit is properly classified an Impacted system.

All final measurements are less than the OCGLw. The sample data passed the Sign Test.

The null hypothesis was rejected. Therefore, the survey unit meets the release criteria.

The dose contribution from residual activity in survey unit SYS-117-01 is 0.37 mrem/yr TEOE, based on the mean activity of all the final measurements.

Survey unit SYS-117-0 I is acceptable for unrestricted use.

REFERENCES STS-005-035, Preparation of Survey Unit Release Records and FSS Final Reports.

STS-004-003, N.S. SA l'ANNAH License Termination Plan, Revision 1.

STS-005-030, Preparation of Final Status Survey Packages.

NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM), Revision I, August 2000.

CR-139, TSO 21-089, Calculations to Support NSS Surface Contamination DCGLs, Revision 1, September 2022.

NUREG-1757, Vol 2, Rev 1, Characterization, Survey, and Determination of Radiological Criteria.

STS-005-031, Calculation oft he Number of Measurements for Final Status Surveys.

STS-005-032, Survey Unit Turnover and Control.

CR-164, TSO 23-126, Calculation of Weighted Efficiencies and MDCs of Ludlum Detectors for Final Status Surveys on the NS SAVANNAH, Rev O 1.

Survey Unit SYS-117-01 Page 18 of3 I Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record 1 --ri -- - t rt (i)

(k)

NUREG-1576, Multi-Agency Radfological Laboratory Analytical Protocols Manual, (MARLAP), July 2004.

16.

STS-005-033, Final Status Survey Data Assessment and Investigation.

ATTACHMENTS Attachment I - Figures and Maps - Calibration Records - Static and Scan Data - Quality Control Assessment - Sign Test - Graphical Presentations Survey Unit SYS-117-01 Neutron Shield Tank, Retained walls Page 19 of3 I

SAVANNAH Technical Staff Survey Unit Release Record 1

I i

.. t..

l -_:_ - t' Survey Unit SYS-117-01 Neutron Shield Tanlc, Retained walls - Figures and Maps Location of the Neutron Shield Tank, Retained Walls 1

- -- d bsi' BOW b Page 20 of31

SAVANNAH Technical Staff Survey Unit Release Record Neutron Shield Tank, Retained Walls, Systematic and Judgmental Static Locations

~--------SYS-117-01--03 YS.117-01--0:

.<1">

'I?

Extenor Shell Port Side <>:1' it YS-117--01-01 VSP Origin Point in Ship Coordinates: Exterior 8" Aft of Frame 110 4'9" to the Port of Centerline 9'6-3/8" above baseline 1' Aft of Frame 115 4' 1 0" to the Starboard of Centerline 9'8-3/8" above baseline SYS.117--01-04 Sbrboard~

YS.117.01-12 YS-117.01.0S lntenor SheR Port Sode YS-1 17-01~8 YS-117.01.07 VSP Origin Point in Ship Coordinates: Interior 8" Aft of Frame 110 4' 8" to the Port of Centerline 9'6-3/8" above baseline I' Aft of Frame 115 4'9" to the Starboard of Centerline 9'8-3/8" above baseline YS-117--01--09 YS.117--01-11 Extenor Shell Starboard Side tntenor Shell S rt>oard Side YS-117-0

  • 4 r,)

SYS.117- 0 LEGEND:

-s ISP 5.1n-.,le t.oca;,on Sc.rface Origm Point Survey Unit SYS-117-01 Neutron Shield Tanlc, Retained walls NOTES:

SAMPLE LOCATIO S CREATED IN VISUAL SAMPLE PLAN NUMBER OF SAMPLES: 17 PLACEMENT METHOD: RANDOM START LOC: RANDOM

  1. vs., 1.01. J BOW D Page 21 of31

SA VANNAH Technical Staff Survey Unit Release Record Survey Unit SYS-117-01 Neutron Shield Tanlc, Retained walls Neutron Shield Tank, Retained Walls, Scan Areas Interior Shell Exterior Shell t

Opening Page 22 of31

S AVANNAH Technical Staff Survey Unit Release Record - Calibration Records Calibration Certificate - ID Number: 25035102000 - 20240305 - 1 RSCS Customer: MattheW G Hunter Radiation Safety & Control Services Inc.

93 Ledge Road Seabrook NH 03874 Test1 Tas12 4.98 kcpm 4.98 kcpm Range Target Value AUTO 500 Kcpm#

AUTO SO Kcpm #

AUTO 5 Kcpm #

AUTO 0.5 Kcpm #

Instrument Ludlum Model 3002 Probe Model Ludlum 43-93 Precision Check Test3 4.98 kcpm Accurac Check As Found 497 Kcpm#

49.8 Kcpm #

4.98 Kcpm #

0.501 Kcpm #

Mean 4.98 kcprn As Left 497 Kcpm#

49.8 Kcpm #

4.98 Kcpm #

0.501 Kcpm #

Readings with

  • Indicate ranges where As-Found readings are >20% orTarget value Readings with ** Indicate As-left readings are > 10% of Target value.

Readings with # Indicate ranges were calibrated using a pulser Serial Number 25035102 Serial Number 421410 Results

!"ass Source ID Pulser98756 Pulser 98756 Pulser 98756 Pulser 98756 Probe lsoto e Efflclenc NIST Source ID Geomet Comment 43-93 421410 Tc-99 43-93 421410 Cs-137(Beta) 43-93 421410 Tc-99 43-93 421410 Cs-1 37(Beta) 43-93 421410 Cs-137(Bela) 43-93 421410 Tc-99 43-93 421410 Cs-137(Bela) 43-93 421410 Tc-99 Physical Checks Light Check or Sclntilatlon Probes: Pass outer Physical Check: Pass Tap Test: Pass Audio Function Check: Pass Cord check: Pass Calibration Date Set: Pass 0.0269 CID (4 Pl) 127356 Tc-99 0.0552 CID (4 Pl) 127357 Cs-137(Beta) 0.0176 CID (4 Pl) 127356 Tc-99 0.0389 CID (4 Pl) 127357 Cs-137(Bela) 0.1599 CID (4 Pl) 127357 Cs-137(Beta) 0.1164 CID (4 Pl) 127356 Tc-99 0.1100 CID (4 Pl) 127357 Cs-137(Bela) 0.0744 CID (4 Pl) 127356 Tc-99 Electronics Checks High Voltage Comments: Calibrated with 20' C to C cable.

Customer Equipment 10.

Calibrated By Nicole Wedlg QC Review By Matthew Hunter Atmosphenc Cond11Jons. Temperature 71 I "F Hum1d1ty 36.0 %, Bacometnc Pressure 30 29 1n/hg Flat Surface On Grate Flat Surface On Grate Flat Surface 314" Above Grata Flat Surface 314" Above Grate Flat Surface On Contact Flat Surface On Contact Flat Surface 314" Above Source Flat Surface 314

  • Above Source As Found As Left 675 Volts 795 Volts Date: Mar 05. 2024 Expires: Mar OS. 2025 QC Date: Mar 05. 2024 In toleronce coodlbons ore based on test results toling within specified limllS with no reduction by the uncertmnty of the meosurernent Unless otherwise stated, this colibmbon was performed by RSCS ot 93 Ledge Rd, Seobrool<, NH utihzmg the following NIST Trocoable sources Putser98758 - (Cal Due Oct 3I 2024)

Worked on cal1brat,on NICOie Wed1g The reported expanded unceno,nty of measurement 1s stated os the standard uncertoonty of measurement mult1pied by the coverage factor k such that the coverage probabiUty corresponds to approxmotely 95**

Unless otherwise stated, cahbrot,ons performed 1n conformance to the following documents ANSI N323AB-20 13; RSCS New Hampshire Rod,ooctive Material License Number 381R RSCS cohbraoon services ore performed in accordance with the RSCS Rodmlion Protecbon Program Manual and Standard Operobng Procedures

"-:acllion S.ltty l COl'Cl'O s<<'olttM N 9ll.ooefto.d S...._NHC3174 t&oO S...'\\S.t.331 lf.Ol 1 *74-17:ll I 2 j

Survey Unit SYS-117-01 Page 23 of31 Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record Calibration Cartlflcate. ID Number: 25035113000. 20240131

Customer: MatthewG Hunter Radiation Safety & Control Services, Inc.

93 Ledge Roed Seabrook NH 03874 Test1 I

Test2 I

5.01 kcpm I

4,99kcpm I

Range Target Value AUTO 500 Kcpm #

AUTO 50 Kcpm #

AUTO 5 Kcpm#

AUTO 0.5 Kcpm #

Instrument Ludlum Model 3002 Probe Model Ludlum 43-37 Precision Check Test3 I

Mean 5.00 kcpm I

5.00 kcpm Accuracy Check As Found As Left 500 Kcpm #

500 Kcpm #

49.9Kcpm#

49.9 Kcpm #

5.01 Kcpm#

5.01 Kcpm #

0.499 Kcpm #

0.499 Kcpm #

Readings wtth

  • Indicate ranges where As-Found readings are >20% of Target value.

Readings wtth " Indicate As-left readings are > 10% of Target value.

Readings wtth # Indicate ranges were calibrated using a pulser Serial Number 2503511 3 Serial Number 190949 I

Results I

Pass Source ID Pulser 98756 Pulser 98756 Pulser 98756 Pulser 98756 Probe Isotope Efficiency NIST Source ID Geometrv Comment 43-37 190949 Tc-99 0.0585 CID (4 Pl) 127356 Tc-99 Flat Surface 3/4" Above Flat Surface 43-37 190949 Cs-137(Beta) 0.1703 CID (4 Pl) 127357 Cs-137(Beta)

Flat Surface 314" Above Flat Surface 43-37 190949 Tc-99 0.0276 CID (4 Pl) 127356 Tc-99 Flat Surface 3/4" Above Grate 43-37 190949 Cs-137(Beta) 0.0387 CID (4 Pl) 127357 Cs-137(Beta)

Flat Surface 314" Above Grate Physical Checks Electronics Checks As Found As Left Outer Physical Check: Pass HI h Volta e 900 Volts 1800 Volts Tap Test: Pass Audio Function Check: Pass Calibration Date Set: Pass Comments: Calibrated with Ludlum 43-37 SIN 190949 using 20' C to C cable for wall and overhead set up.

Customer Equipment ID:

Calibrated By Nicole Wedlg QC Review By Matthew Hunter Atmospheric Conditions - Temperature 70 O "F, Humidity* 24.0,., Borometnc Pressure:30 12 inlhg Date: Jan 31. 2024 Expires: Jan 31. 2025 QC Date: Jan 31. 2024 In tolerance cond1Uons ore based on test results lolling within spec1f,ed limits with no reduction by the uncertainty of the measurement This colibrotion wos performed by RSCS using the following NIST Traceable sources Pulser 98756 - (Col Due Oct 31. 2024)

Worked on colibrotion Nicole Wed1g The reported expanded uncertoInty of meosurement Is stoled os the stondord uncerto111ty of meosurement mulupNed by the coveroge foctor k such thot the coverage probability corresponds to opproximately 95°.

Unless otherwise stated, colibrotions performed in conformance to the following documents ANSI N323AB-20 13, RSCS New HdmpshIre Radioactive Moteriol l.Jcense Number 381R RSCS cohbrott00 serv,ces ore performed in accordance wrth the RSCS Rodmtion Protection Program Manual and Standard Operaung Procedures Calibrobon Laboratory Is operoted In accordance with ANSI/NCSL 2540- t-1994.

RSCS, Inc has been assessed by ANAB and meets the requirements of ISO/IEC 17025 20 17 while demonstrot1ng technical compelence In the field of calibration Refer to the Scope of Accred1tobon AC-2079 for information on the types of calibrations to which this occredijation a,plies This cohbrotion cert1ficote shall not be reproduced except in full Without the express wntten consent of RSCS, Inc RaGll'°9'\\S.tetylCofltro $ervt,c.M l"C:

9l L'"9fi RON S.WOOk hH Cl874 (800* S1S-Uli i<<lll 474-6723 Survey Unit SYS-117-01

..,....,,_OHfetycom Neutron Shield Tank, Retained walls Ill Page 24 of 31

SA VANNA H Technical Staff Survey Unit Release Record Calibration Certificate - ID Number: 25035132000 - 20240305 - 1 RSCS Customer: Matthew G Hunter Radiation Safety & Control Services. Inc.

93 Ledge Road Seabrook NH 03874 Instrument Ludlum Model 3002 Probe Model Ludlum 43-93 Serial Number 25035132 Serial Number 421425 Precision Check Test1 I

Test2 I

Test3 I

Mean I

Results 5.00 kcpm I

4.99kcpm I

4.99 kcpm I

4.99 kcpm I

Pass Accuracy Check Range Target Value As Found As Left Source ID AUTO 500 Kcpm #

499 Kcpm #

499 Kcpm #

Pulser 98756 AUTO 50 Kcpm #

50 Kcpm #

50 Kcpm #

Pulser 98756 AUTO 5 Kcpm #

5 Kcpm#

5 Kcpm#

Pulser 98756 AUTO 0.5 Kcpm #

0.498 Kcpm#

0.498 Kcpm#

Pulser 98756 Readings with

  • Indicate ranges where As-Found readings are >20% of Target value.

Readings with.. Indicate As-left readings are >10% ofTarget value.

Readings with # indlcete ranges were calibraled using a pulser Probe Isotope 43-93 421425 Tc-99 43-93 421425 Cs-137(Beta) 43-93 421425 Cs-137(Beta) 43-93 421425 Tc-99 43-93 421425 Cs-137(Beta) 43-93 421425 Tc-99 43-93 421425 Cs-137(Beta) 43-93 421425 Tc-99 Physical Checks Light Check of Sclntllatlon Probes: Pass Outer Physical Check: Pass Tap Test: Pass Audio Function Check: Pass Cord check: Pass Calibration Date Set: Pass Efficiency 0.0243 C/D (4 Pl) 0.0505 C/D (4 Pl) 0.0398 C/D (4 Pl) 0.0177 C/D (4 Pl) 0.1620 C/D (4 Pl) 0.1108 C/D (4 Pl) 0.1193 C/D (4 Pl) 0.0821 C/D (4 Pl)

Comments: Calibrated with 20' C to C cable.

Customer Equipment ID:

NIST Source ID 127356 Tc-99 127357 Cs-137(Beta) 127357 Cs-137(Beta) 127356 Tc-99 127357 Cs-137(Beta) 127356 Tc-99 127357 Cs-137(Beta) 127356 Tc-99 Electronics Checks High Voltage Calibrated By Nicole Wedlg QC Review By Matthew Hunter Atmosphenc Conditions - Temperature 7 I I

  • F, Humidity 36 0 ' ** Barometr1c Pressure 30 29 In/hg Geometry Comment Flat Surface On Grate Flat Surface On Grete Flat Surface 3/4
  • Above Grate Flat Surface 3/4" Above Grate Flat Surface On Contact Flat Surface On Contact Flat Surface 3/4" Above Source Flat Surface 3/4" Above Source As Found As Left 678 Volts 780 Volts Date: Mar 05, 2024 Expwes: Mar05, 2025 QC Date: Mar 05, 2024 In tolerance condibons are based on test results fnlting within specifl8d bm~s with no reduction by the uncef10inty of the measurement Unless otherwise stated, this cahbronon was performed by RSCS at 93 Ledge Rd Seabrool<. NH uti1zmg the foUOW1ng NIST Tr.1ceabte sources Pulser 98756- (Cal Due Oct 31, 2024)

Worked on cahbrotJon Nicole Wed,g The reponed expanded uncertainty ol measurement Is stoled as the standard uncertainty of measurement mult1pbed by the cowroge facto, k such that the coverage probability corresponds to approximately 95°0.

Unless otherwise stoled, cahbrat,ons performed in conformance to the following documents ANSI N323AB-2013, RSCS New 1-ampsh,re Radioactive Material l.Jcense Number 381 R RSCS cahbretion services are performed In acco,donce ~

the RSCS Rodiot,on Protecnon Program Monuol ond Standard Operobng Procedures Raoi:tlKln ~lt(y & Co,1tn> Ser.Ket lric 93 Led91 l\\oa6 Se~ NH 0)17' (800 S~S-!lli

!601) 474-6723 I :2 1zi Survey Unit SYS-117-01 Page 25 of3 l Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record - Static Data Count Rate Total Weighted Eff Meter ID Measurement ID (cpm)

(c/d) 25035132 SYS-117-01-01 95 0.0858 25035132 SYS-117-01-02 94 0.0858 25035132 SYS-117-01-03 105 0.0858 25035132 SYS-117-01-04 97 0.0858 25035132 SYS-117-01-05 75 0.1530 25035132 SYS-117-01-06 68 0.1530 25035132 SYS-117-01-07 62 0.1530 25035132 SYS-117-01-08 49 0.1530 25035132 SYS-117-01-09 83 0.0858 25035132 SYS-117-01-10 107 0.0858 25035132 SYS-I 17-01-11 481 0.0858 25035132 SYS-117-01-12 182 0.0858 25035132 SYS-117-01-13 76 0.1530 25035132 SYS-117-01-14 58 0.1530 25035132 SYS-117-01-15 64 0.1530 25035132 SYS-117-01-16-J 836 0.1530 25035132 SYS-117-01-17-J 537 0.0858 25035102 SYS-117-01-02-D 70 0.0849 Note: Meter IDs 25035132 and 25035102 are connected to a Ludlum model 43-93 detector with an area of I 00 cm2.

Survey Unit SYS-117-01 Page 26 of31 Neutron Shield Tank, Retained walls

S AVANNA H Technical Staff Survey Unit Release Record Meter ID 25035113 25035113 25035113 25035132 25035132 25035132 25035113 25035113 25035113 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035113 25035113 25035113 25035113 25035113 25035113 - Scan Data Min/Max Range Average Location (cpm)

(cpm)

SA-01 204/1400 802 SA-02 80/275 177.5 SA-03 52/160 106 SA-04 30/120 75 SA-05 30/120 75 SA-06 30/120 75 SA-07 90/400 245 SA-08 60/250 155 SA-09 43/367 205 SA-10 60/4200 2130 SA-11 80/205 142.5 SA-12 80/205 142.5 SA-01 80/110 95 SA-07 80/180 130 SA-03 30/120 75 SA-05 61/183 122 SA-06 61 /183 122 SA-04 80/292 186 SA-05 43/117 80 SA-06 96/271 183.5 SA-10 52/400 226 SA-11 36/1500 768 SA-12 48/1000 524 t

Total Weighted Eff (c/d) 0.1506 0.1506 0.1506 0.1128 0.1128 0.1128 0.0878 0.0878 0.0878 0.0632 0.0632 0.0632 0.1128 0.0632 0.1128 0.1128 0.1128 0.1506 0.1506 0.1506 0.0878 0.0878 0.0878 Note: Meter ID 25035113 is connected to a Ludlum model 43-37 detector with an area of 584 cm2. Meter ID 25035132 is connected to a Ludlum model 43-93 detector with an area of I 00 cm2.

Survey Unit SYS-117-01 Page 27 of3 I Neutron Shield Tank, Retained walls

S AVANNAH Technical Staff Survey Unit Release Record - Quality Control Assessment Measurement Value (dpm/100 cm2)

Initial measurement I 096.13 Replicate measurement 824.25 Average 960.19 Absolute Value of the difference 271.88 Condition Absolute value of the Control Limit (dpm/100 cm2) difference (dpm/100 cm2)

Average < 52,300 271.88 11087.6 Survey Unit SYS-117-01 Neutron Shield Tank, Retained walls t

Result Pass Page 28 of3 I

S AVANNAH Technical Staff Survey Unit Release Record - Sign Test Measurement Result DCGLw - Result ID (dpm/100 cm2)

(dpm/100 cm2)

SYS-117-01-01 1107.79 68592.21 SYS-117-01-02 1096.13 68603.87 SYS-117-01-03 1224.40 68475.60 SYS-117-01-04 1131.12 68568.88 SYS-117-01-05 490.23 69209.77 SYS-117-01-06 444.48 69255.52 SYS-117-01-07 405.26 69294.74 SYS-117-01-08 320.28 69379.72 SYS-117-01-09 967.86 68732.14 SYS-117-01-10 1247.73 68452.27 SYS-117-01-11 5608.94 64091.06 SYS-117-01-12 2122.30 67577.70 SYS-117-01-13 496.77 69203.23 SYS-117-01-14 379.11 69320.89 SYS-117-01-15 418.33 69281.67 SYS-117-01-16-J 5464.45 64235.55 SYS-117-01-17-J 6261.95 63438.05 Parameter Result Number of Measurements 17 Number ofS+

17 Critical Value 12 Meets / Doesn't Meet Acceptance Criteria Meets Survey Unit SYS-117-0 I Neutron Shield Tank, Retained walls Sign

+1

+l

+l

+l

+1

+1

+l

+l

+l

+1

+l

+l

+l

+1

+l

+l

+1 Page 29 of3 l

S AVANNA H Technical Staff Survey Unit Release Record - Graphical Presentations Quantile Plot of Gross Activity Concentration 7100 6100

,....._ 5100 r,

E u

0 0

~ 4100 C

Cl.

"O g 3100 0 u -

(.)

<( 2 100 1100 100 0%

10%

20%

30%

40~-o 50%

60°-o 70%

80%

Survey Unit SYS-117-0 I Neutron Shield Tank, Retained walls rt 90%

100%

Page 30 of3 I

SAVANNAH Technical Staff Survey Unit Release Record Histogram Survey Unit Number: SYS-117-01 Neutron Shield Tank, Survey Unit Name: Retained Walls 9

8 7

6

..,.... g 5 CJ

l O"'

~ 4 L.

2 0

1063 Survey Unit SYS-117-0 I 1806 2548 3291 1034 4777 l ppcr end \\alue (dpm 100 crn 2)

Neutron Shield Tank, Retained walls t

5519 6262 Page 31 of31

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