ML25328A171

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Us Dept of Transportation - Nuclear Ship Savannah, Survey Unit Release Record Survey Unit STR-101-01 Containment Vessel (Cv) - 1st Level (Tanktop), Starboard Side
ML25328A171
Person / Time
Site: NS Savannah
Issue date: 11/20/2025
From: Hollenbeck P
US Dept of Transportation, Maritime Admin, Nuclear Ship Support Services
To:
Office of Nuclear Reactor Regulation
References
Download: ML25328A171 (0)
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U.S. Department of Transportation Maritime Administration Office of Ship Operations Nuclear Ship Savannah Survey Unit Release Record Survey Unit STR-101-01 Containment Vessel (CV) - 1st Level (Tanktop ), Starboard Side Approved:

Senior Technical Advisor Prepared by:

Nuclear Ship Support Services, LLC

SAVANNAH Technical Staff Survey Unit Release Record PREPARED BY I DATE:

PEER REVIEW / DATE:

DECOMMISSIONING PROGRAM MANAGER REVIEW /DATE:

INDEPENDENT REVIEW /

DATE:

FSS MAN AGER REVIEW / DATE:

LICENSING and COMPLIANCE MANAGER REVIEW/ DATE:

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

Survey Unit STR-101-01 Pete HO II en bee k Digitally signed by Pete Hollenbeck Date: 2025.03.12 11 :33:24 -04'00' Pete Hollenbeck, CHP D. Roberson Douglas Roberson Date Digitally signed by D. Roberson Date: 2025.03.12 10:49:33 -05'00' Date Soeuth Caleb Soeu n Digitally signed by Soeuth Caleb Soeun Date: 2025.03.17 12:59:19-04'00' Soeuth C. Soeun James Reese, CHP, RRPT James Reese Date Digitally signed by James Reese, CHP, RRPT Date: 2025.03.18 09:19:38 -07'00' Date Digitally signed by Daniel R.

Daniel R. Mihalik Mihalik Daniel Mihalik John Osborne LCM John Osborne 3/19/2025 Submitted Eric Darois Date: 2025.03.19 16:05:48 -04'00' Date Digitally signed by: John Osborne LCM ON: CN = John Osborne LCM email =

jmosborne@nsss.llc C = AD Date: 2025.03.28 17:12:42-05'00' Date 3/28/2025 Approved 9/2/2025 Date Page 2 of 32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record TABLE OF CONTENTS 1 --+ -+- 1st

1.

EXECUTIVE

SUMMARY

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

2.

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

3.

CLASSIFICATION BASIS................................................................................................... 7

4.

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

5.

SURVEY DESIGN............................................................................................................... 11

6.

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

7.

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

8.

QUALITY CONTROL........................................................................................................ 18

9.

INVESTIGATIONS AND RESULTS................................................................................ 18

10. REMEDIATION AND RESULTS...................................................................................... 18
11. CHANGES FROM THE FINAL STATUS SURVEY PACKAGE................................. 18
12. DA TA QUALITY ASSESSMENT...................................................................................... 19
13. ANOMALIES........................................................................................................................ 19
14. CONCLUSIONS................................................................................................................... 19
15. REFERENCES..................................................................................................................... 19
16. ATTACHMENTS................................................................................................................. 20 Survey Unit STR-101-01 Page 3 of32 Containment Vessel (CV)- 1st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record LIST OF TABLES l - -

-- I t Table 4 Radionuclide Fractions and Normalized Fractions............................................... 8 Table 4 15 mrem/y DCGLs for ROC and Ni-63.................................................................. 9 Table 4 Re-normalized Co-60 and Cs-137 Fractions........................................................ 10 Table 4 Operational DCGLs................................................................................................ 10 Table 5 STR-101-01 Systematic Measurement Designations........................................... 12 Table 5 Scanning Coverage................................................................................................. 12 Table 5 Investigation Levels................................................................................................ 13 Table 7 Summary of Systematic, Judgmental, and QC Static Measurements................ 16 Table 7 Basic Statistical Properties of Static Measurement Population.......................... 17 Table 7 Scan Measurement Summary................................................................................ 17 Survey Unit STR-101-01 Page 4 of32 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record LIST OF ACRONYMS AND ABBREVIATIONS ALARA As Low As Reasonably Achievable CV Containment Vessel CR Contractor Report DQO Data Quality Objective DCGL Derived Concentration Guideline Level ETD Easy-to-Detect FSS Final Status Survey HSA Historical Site Assessment 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 SA VANNA H QC Quality Control RASS Remedial Action Support Survey ROC Radionuclides of Concern TEDE Total Effective Dose Equivalent UBGR Upper Bound of the Gray Region VSP Visual Sample Plan Survey Unit STR-101-01 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side l - --- i rt Page 5 of32

SAVANNAH Technical Staff Survey Unit Release Record

1.

EXECUTIVE

SUMMARY

l --ri -- - i rt This Survey Unit Release Record for survey unit STR-101-01, Containment Vessel (CV)

- 1st Level (Tanktop), Starboard Side, 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 [L TP], STS-004-003, Revision 1, 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 1, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSlM), Reference (d).

This survey unit has a MARSSIM classification of I. A survey package was designed based upon the use of the Sign Test as the nonparametric statistical test for compliance. Both the Type l (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. Two (2) judgmental static beta measurements were acquired as per the sample plan. During survey implementation, eleven (11) static measurements were collected in locations that were identified as exceeding the 2,500 cpm scan action level and four (4) static measurements were collected following the installation of new fiberglass grating in the space. Surface scanning was performed on I 00% of the accessible total shell surface area in the survey unit. The data assessment results for survey unit STR-101-01 show that the maximum gross activity concentration among all the final systematic and judgmental measurements is equal to 37,716.98 dpm/100 cm2, which is 72.1% 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 STR-101-0 I is acceptable for unrestricted use. The mean gross activity concentration among all the final systematic and judgmental measurements is equal to 9,532.76 dpm/100 cm2, which is 13.7% of the 15 mrem/y gross activity DCGLw of 69,700 dpm/100 cm2. The mean gross activity concentration is equal to 2.05 mrem/y for the survey unit.

2.

SURVEY UNIT DESCRIPTION STR-101-01 is an impacted Class I survey unit. The CV 1st level housed the reactor plant and some supporting systems. The reactor rested on a support ring on the CV 1st level, and the entire CV rested on a cradle located on the tank top. The survey unit consists of the internal surfaces of the starboard side to the centerline of the CV structure. The l st-level deck, shell, ring stiffeners, and reactor vessel foundation up to the 14-foot elevation are considered one and referred to as the CV shell. Based upon Computer Aided Design drawings, the 1st level starboard-side half of the CV shell surface area is approximately Survey Unit STR-101-01 Page 6 of32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record 64.84 square meters (64.84 m2); this includes the shell surface above 2 meters. Refer to of this report for figures and maps depicting survey unit STR-101-01.

3.

CLASSIFICATION BASIS Based on the NSS Historical Site Assessment [HSA], Reference (e), survey unit STR-101-01, identified as survey unit 101 A 1 in the HSA, was identified as a Class 1 structure survey unit. Primary coolant leaks were experienced from time to time, as was typical of nuclear power plants of the era. Coolant was released as steam condensed and drained to the bottom of the containment vessel, from which it was collected in tank PD-T4, the containment drain tank. In August of 1966, a leak produced low-level contamination in the containment vessel that was decontaminated using a detergent solution. In 1968, a primary system leak from a pressure relief system isolation valve occurred. In 1969, a primary system leak from a control rod drive buffer seal was observed. On another occasion in 1969, 3500 gallons leaked from a primary coolant pump vent pipe. Based upon a review of the historical information, the results of the characterization survey data, the 2024 Remedial Action Support Survey (RASS) STR-101-RASS-01-Rev 0, and the completion of a final Survey Unit Classification Worksheet, the correct final classification of survey unit STR-101-0 l is Class 1.

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 L TP. The appropriate design for a given survey was developed using the DQO process as outlined in STS-005-030, 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 STR-101-01 does 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).

Survey Unit STR-101-01 Page 7 of32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

S AVANNAH Technical Staff Survey Unit Release Record MARAD Contractor Report (CR)-139, Calculations to Support NSS Surface Contamination DCGLs, Reference (t) 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 I,

Consolidated Decommissioning Guidance Characterization, Survey, and Determination of Radiological Criteria, Reference (g). 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-L TP 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 fro1111 the initial suite. Table 4-1 presents the initial suite ofROC for the decommissioning of the NSS, and the normalized mixture fractions based on the radionuclide mixture.

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 5.61E-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 l.27E-04 2.l lE-05 Ag-108m 8.30E-04 1.38E-04 Cs-137 4.57E-01 7.61 E-02 7.61E-02 H-3 l.93E-03 3.21 E-04 Fe-55

8. l0E-03 1.35E-03 Am-241 5.79E-07 9.66E-08 Pu-239/240 4.81E-07 8.0IE-08 Totals 6.00E+00 1.00E+00 9.93E-01 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 LTP.

Survey Unit STR-101-0 I Page 8 of32 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record 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 t

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 DCGLHTD surrogate =

(/ HTD:ETDXDCGLETo)+ DCGLHTD Equation I Where:

DCGLEm the DCGL for the easy-to-detect radionuclide DCGLttm the DCGL for the hard-to-detect radionuclide Fttm: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.

DCGLco-60 surrogate = 2.37E + 04 X (

253 E+~a

= 2.36E+04 dpm/100 cm2 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:

n DCGLn Gross Activity DCGLw =

1 fraction of the total activity contributed by radionuclide n

= the number of radionuclides

= DCGL for the Radionuclide of Concern (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 must be re-normalized for use in Equation 2. Table 4-3 presents the re-normalized fractions for each radionuclide.

Survey Unit STR-101-01 Page 9 of32 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record Table 4-3 -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 5.61E-03 Co-60 l.63E-02 1.63E-02 I.76E-01 Ni-63 9.00E-01 Sr-90 l.54E-06 Tc-99 2.I IE-05 Ag-108m l.38E-04 Cs-137 7.61E-02 7.61 E-02 8.24E-0I H-3 3.21E-04 Fe-55 l.35E-03 Am-241 9.66E-08 Pu-239/240 8.0IE-08 Totals 1.00E+00 9.24E-02 1.00E+00 Solving Equation 2, using the re-normalized Co-60 and Cs-I 37 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+04 1.20E+05 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 10% of the DCGL is preferable and up to 50% is acceptable. Because the Survey Unit STR-101-01 Page IO of32 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side

I l_

SAVANNAH Technical Staff Survey Unit Release Record background is low on the NSS, the MDCs for most static and scan measurements were less than 10% of the 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 MARAD procedure STS-005-031, Calculation of the Number of Measurements for Final Status Surveys, Reference (h). 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 ( u), which is the standard deviation of the data set used for survey design. The optimal value for the relative shift should range between one (I) and three (3). If the relative shift is less than one (I), or greater than three (3), then the value of two (2) will be used for the relative shift.

A RASS survey of the CV 151 level was performed on April 9, 2024 and a scoping survey of the Neutron Shield Tank footprint was performed on April 20, 2023. A total of forty-four (44) static measurements and 50 smears were collected. Only nine (9) smears had positive alpha activity at 4.21 dpm/100 cm2. The maximum beta activity was 305.20 dpm/100 cm2. The average total surface activity concentration and standard deviation of the measurements was 6,868 and 9,907 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 STR-101-01 is based upon the RASS survey results and was calculated as follows:

52,300-26,150 Relative Shift (Ncr) = ------ = 2.64 9,907 Since the calculated relative shift fell between the optimal values of 1 and 3 no adjustment was required placing the relative shift at 2.64. 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 STR-101-01.

The survey unit was designated Class I; therefore, 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). Input 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 l ). Table 5-1 lists the systematic measurements to be collected for FSS of survey unit STR-101-01.

Survey Unit STR-101-01 Page 11 of32 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record l - --- 4 i rt Table 5 STR-101-01 Systematic Measurement Designations Label LX(m)

LY(m)

Surface STR-101-01-01 3.75

-4.72 CV Shell STR-101-01-02 6.14

-4.72 CV Shell STR-101-01-03 8.53

-4.72 CV Shell STR-101-01-04 10.92

-4.72 CV Shell STR-101-01-05 2.55

-2.65 CV Shell STR-101-01-06 4.94

-2.65 CV Shell STR-101-01-07 7.33

-2.65 CV Shell STR-101-01-08 9.72

-2.65 CV Shell STR-101-01-09 12.11

-2.65 CV Shell STR-101-01-10 1.36

-0.58 CV Shell STR-101-01-11 3.75

-0.58 CV Shell STR-101-01-12 6.14

-0.58 CV Shell STR-101-01-13 8.53

-0.58 CV Shell STR-101-01-14 10.92

-0.58 CV Shell STR-101-01-15 13.31

-0.58 CV Shell 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 STR-101-01-09 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 STR-101-01-16-J and STR-101-01-17-J. Those locations are documented on the field forms.

For this Class 1 structure 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 Class l 100%

For survey unit STR-101-01, a single scan area was established. The survey package stated to scan 100% of the accessible area in each scan area. Refer to Attachment I for figures and maps depicting the measurement and scan locations in survey unit STR-101-01.

Survey Unit STR-101-01 Page 12 of32 Containment Vessel (CV) - 1st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record 1

J } t For this Class 1 structure 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 Survey Unit Fixed Measurements Scan Measurements Classification Class 1

> Operational DCGLw

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

An additional action level was specified in the survey package. lf 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.

6.

SURVEY IMPLEMENTATION For survey unit STR-101-0 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 the beta mode. Surface scans were also performed utilizing the Ludlum 43-37 large area gas proportional detector connected to a Ludlum 3002 operating in beta mode.

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 (i). No conditions prohibited the proper collection of static and scan measurements.

FSS field activities were conducted under the approved FSS Package Number NSS-FSSP-STR-101-01-00-00, which included DQOs, survey design, detailed FSS instructions, survey maps and survey forms. FSS field activities were projected to take four (4) working days to complete. A daily briefing was conducted to discuss the expectations for job performance and to review the 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 four (4) days to complete and were performed on July 15, 2024, July 16, 2024, July 24, 2024, and July 26, 2024. On Dec 11, 2024, a single static measurement was collected at the location of an elevated scan measurement in SA-01, identified as SA-01-02-J, that was missed on July 26, 2024.

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.

Survey Unit STR-101-01 Page 13 of32 Containment Vessel (CV) - !st Level {Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record 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.

The entire scan area, SA-01, was scanned, resulting in 100% of the total shell surface area being scanned. The total scan area meets the scan coverage requirements for a Class I area as shown in LTP 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. Eleven locations were identified that exceeded the 2,500 cpm scan action level. Those locations were marked for follow-up static measurements. They were identified as judgmental measurements. Static measurements were collected on the eleven locations on July 24, 2024, and July 26,2024. The eleven locations were in four (4) separate areas that were approximately three (3) feet by one (1) foot each. The technicians inadvertently misnumbered the static measurement location starting at SA-01-02-J instead of SA-01-01-J. After remediation, follow-up static measurements were collected. Additional details can be found in Sections 9 and 10.

Following the RASS of the CV 1st level (Tank Top) and just prior to the FSS, new fiberglass grating was installed on the curvature walking surfaces of the CV shell. Because of this new grating, a second scan area was created, SA-02. Judgmental scanning in SA-02-J was performed on the new grating. Four additional judgmental statics, STR-101 18-J through STR-101-01-21-J, were added, capturing the new fiberglass grating.

The implementation of survey specific QC measures included the collection of one (I) replicate static measurement. The random location of the replicate measurement was STR-101-01-09 and identified as STR-101-01-09-D. That measurement was collected with a different instrument, but the same make and model used for the original measurement.

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-I 64, Reference G).

For example, (derived from NUREG-1507) if the 4n contact Tc-99 efficiency is 0.1002 c/d Survey Unit STR-101-01 Page 14 of32 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record l - -

- d I r 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 highest ambient background count rate from a I-minute count was 99 cpm. Rounding up the count rate to l 00 cpm, using the contact detector weighted efficiency of 0.0858 c/d and using LTP 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 577 dpm/100 cm 2. This value is 1.1 % of the operational DCGLw and less than 1 %

of the gross activity DCGLw. Table 7-1 presents the activity concentration for all static measurements. Using the same 100 cpm background count rate and using the contact detector weighted efficiency of 0.0159 c/d for a fiberglass grating surface, results in an MDC of 3,119 dpm/100 cm2. This value is 6.0% of the operational DCGLw and 4.5% of the gross activity DCGLw.

Table 7-1, on the next page, presents the act1v1ty concentration for all final static measurements. Remainder of this page left blank intentionally.

Survey Unit STR-101-01 Page 15 of32 Containment Vessel (CV) - 1st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record J - --- s brl Table 7 Summary of Systematic, Judgmental, and QC Static Measurements Activity Concentration Measurement ID (dpm/100 cm2)

SA-01-01-J Not Used, See Section 6 SA-01-02-J 21796.07 SA-01-03-J 1492.61 SA-01-04-J 23205.37 SA-01-05-J 3451.65 SA-01-06-J 20406.74 SA-01-07-J 10564.86 SA-01-08-J 24488.08 SA-01-09-J 37716.98 SA-01-10-J 21456.22 SA-01-11-J 33695.29 SA-01-12-J 17499.81 STR-101-01-01 3463.31 STR-101-01-02 2262.23 STR-101-01-03 3066.84 STR-101-01-04 1935.72 STR-101-01-05 1667.52 STR-101-01-06 1620.88 STR-101-01-07 2017.35 STR-101-01-08 1317.69 STR-101-01-09 1376.00 STR-101-01-10 5107.51 STR-101-01-11 1387.66 STR-101-01-12 1107.79 STR-101-01-13 827.93 STR-101-01-14 1445.96 STR-101-01-15 1714.17 STR-101-01-16-J 23321.98 STR-101-01-17-J 2553.76 STR-101-01-18-J 5292.87 STR-101-01-19-J 8884.46 STR-101-01-20-J 5859.97 STR-101-01-21-J 13043.15 STR-101-01-09-D 1054.34 The raw static data with detector efficiencies are presented in Attachment 3.

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

Survey Unit STR-101-0 I Page 16 of32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record 1

Table 7 Basic Statistical Properties of Static Measurement Population Parameter Value Units Minimum Measurement 827.93 dpm/100 cm2 Maximum Measurement 37716.98 dpm/100 cm2 Mean 9532.76 dpm/100 cm2 Median 3457.48 dpm/100 cm2 Standard Deviation 10644.08 dpm/100 cm2 Coefficient of Variation 1.12 unitless Residual activity dose rate 2.05 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 STR-101-01, the calculated dose from residual activity is 2.05 mrem/yr.

The scan MDC for the Ludlum 43-37 detector was calculated using the rounded count rate of250 cpm, the detector weighted efficiency of0.0802 c/d at a distance of 0.75 inches and using L TP 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 0.711 seconds. The resulting MDC for scanning is 604 dpm/100 cm2. This value is 1.2% of the operational DCGLw and less than 1 % of the gross activity DCGLw.

The scan MDC for the Ludlum 43-93 detector was calculated using the highest rounded count rate of 100 cpm, the detector weighted efficiency of 0.0632 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 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 is 2,154 dpm/100 cm2. This value is 4.1 %

of the operational DCGLw and 3.1 % of the gross activity DCGLw. Using the same l 00 cpm background count rate and using the detector weighted efficiency of 0.0142 c/d for a fiberglass grating surface at a distance of 0.75 inches, results in an MDC of 9,616 dpm/100 cm2. This value is 18.4% of the operational DCGLw and 13.8% of the gross activity DCGLw.

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

Table 7 Scan Measurement Summary Low to High Range Average Scan ID (dpm/100 cm2)

(dpm/100 cm2)

SA-01 426.93 - 63318.59 31872.76 SA-02-J 4734.3 I - 15474.84 10104.58 The raw scan data with detector efficiencies are presented in Attachment 3.

Survey Unit STR-101-01 Page 17 of32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record

8.

QUALITY CONTROL l ---- d J rt The implementation of survey specific QC measures included the collection of one (1) replicate static measurement (STR-101-01-09-O) for analysis. The acceptance criteria for replicate static measurements is defined by NUREG-1576, Multi-Agency Radiological Laboratory Analytical Protocols Manual (MARLAP) Volume I, Appendix C, Section C.4.2.2 Duplicate Analyses, Reference (k). 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 (10). 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 Eleven locations triggered the scan action level of 2,500 cpm, requiring a confirmatory measurement at each location. Three of the static measurements triggered the Investigation Level of 52,300 dpm/100 cm2. Those locations are identified as SA-01-02-J at 98,885.21 dpm/100 cm2, SA-01-03-J at 67,633.75 dpm/100 cm2 and SA-01-12-J at 59,999.35 dpm/100 cm2. The results for the remaining measurements ranged from I, 131.12 dpm/100 cm2 to 37,716.98 dpm/100 cm2. None of these locations were part of the fifteen systematic/unbiased measurement locations.

10.

REMEDIATION AND RESULTS Remediation was performed in four separate areas, three (3) feet by one (1) foot each encompassing nine of the eleven locations exceeding the 2,500 cpm scan action level. Two of the locations were inaccessible for decon. All post remediation static measurements are less than the operational DCGLw and are presented in Table 7-1.

11.

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

A field change was initiated to the FSS package. As described in Section 6, a separate scan area, SA-02-J, was created for the new fiberglass grating. Four additional judgmental static measurements, STR-101-01-18-J through STR-101-01-21-J, were added and collected on the fiberglass grating.

Survey Unit STR-101-01 Page 18 of32 Containment Vessel (CV) - 1st Level (Tanktop ), Starboard Side

SAVANNA H Technical Staff Survey Unit Release Record

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 (I) for 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 Class 1.

The preliminary data review consisted of calculating 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 the instance that no measurements exceed the DCGLw, the test was conducted to demonstrate coherence to the statistical principles of the DQO process. The Sign Test was performed on the data and compared to the original assumptions of the DQOs. The evaluation of the Sign Test results clearly demonstrates that the survey unit passes the unrestricted release criteria, thus, the null hypothesis is rejected. The results of the Sign Test are presented in Attachment 5.

13.

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

14.

CONCLUSIONS Survey unit STR-101-0 I has met the DQOs of the FSS package. The survey unit is properly classified as Class 1.

All final measurements are less than the DCGLw. 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 STR-101-0 I is 2.05 mrem/yr TEDE, based on the mean activity of all the final measurements.

Survey unit STR-101-01 is acceptable for unrestricted use.

15.

REFERENCES (a)

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

(b)

STS-004-003, N.S. SA VANNAH License Termination Plan, Revision l.

(c)

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

Survey Unit STR-101-01 Page 19 of32 Containment Vessel (CV) - !st Level (Tanktop), Starboard Side

SAVANNAHTechnical Staff Survey Unit Release Record 1 - --- +

  • 3 1 (d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

(I)

16.

NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM), Revision 1, August 2000.

CR-003, STS-109, Historical Site Assessment, Revision 1, 2023.

CR-139, TSD 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 of the 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.

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

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

ATTACHMENTS - Figures and Maps - Calibration Records - Static and Scan Data - Quality Control Assessment - Sign Test - Graphical Presentations Survey Unit STR-101-01 Page 20 of32 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record Survey Unit STR-10 I -0 I - Figures and Maps Location of the Containment Vessel (CV)- 1st Level (Tanktop)

~

Containment Vessel (CV) - I st Level (Tanktop), Starboard Side t

Page 21 of32

SAVANNAH Technical Staff Survey Unit Release Record Containment Vessel (CV) - 1st Level (Tanktop) Starboard Side Systematic and Judgmental Static Locations NSS-FSSP-STR-101-01 LEGEND:.

VSP Origin Point in Ship Coordinates:

2'0" Aft of Frame 121 On Centerline 13' IO" above baseline NOTES:

CV SHELL SHOWN I FLATTENED VIEW (5' to 14')

SAMPLE LOCATIONS CREA TEO IN VISUAL SAMPLE PLAN NUMBER OF SAMPLES: 15 PLACEMENT METHOD* SYSTEMATIC START Loe* RANDOM BOW h Survey Unit STR-101-01 Page 22 of32 Containmenl Vessel (CV) - I st Level (Tanktop), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record Containment Vessel (CV) - 1st Level (Tanktop) Starboard Side Scan Areas r r r 125 120 NSS-FSSP-STR-101-01 NOTE:

Shell curvature was flattened out for sampling placement purposes.

11 Point of Origin, located on the AFT end of CV on centerline and just under the 2nd level at 14-foot elevation.

Survey Unit STR-I 0I-0 I Containment Vessel (CV) - I st Level (Tanktop), Starboard Side t

l r

l 10 105 SA-01 BOW b i'

r r 1 10C Page 23 of32

SAVANNAH Technical Staff Survey Unit Release Record - Calibration Records Calibration CtrtiflC.tta

  • ID Number: 25035113000
  • 20240131
  • 0 RSCS customer: MatthewG Hunter Rad atoon Safety & Control SeMces, Inc.

93 ledge Road Seabrook NH 0387 4 Testl I

Test2 I

5.01 kcpm I

4.99 kcpm I

Ranqe Tarqet Value AUTO 500 Kcpm#

AUTO 50 Kcpm#

AUTO 5 KcpmJi AUTO 0.5Kcpm#

Instrument Ludlooi Model :l002 Probe Model LU<!lum 43-37 Precision Check Tesl3 I

Mean 5.00 kcpm I

5.00 kcpm Accuracy Check As Found Aslell 500Kcpm#

500 Kcpm#

49 9 Kcpmtt 49 9Kcpmtt 5.01 Kcpmll 5.0 1 Kcpm#

0.499Kcpmli 0.499Kcpmll Readings Wltl1

  • Indicate ranges where As-Found readings are >20% ol Target vall.Ie Readings Y.'lth ** Indicate As-lell readings are >10% ollarget value.

Readings with# indicate ranges were calibrated uSing a pulser Serial Number 25035113 Serial Number 190949 I

Results I

Pass Source ID Pulser 98756 Pulser 98756 Pulser 98756 Pulser 96756 Probe Isotope Efficleney NtST Source to Geometry Comment 43-37 190949 Tc-99 0.0585 CID (4 Pi) 127356 Tc-99 Flat surface 3/4" Above Aat Surface 43-37 190949 Cs-137(Beta) 0 1703 CID (4 Pi) 127357 Cs-I37(Beta)

Flat surface 3/4" AfXJve Aat Surface 43-37 190949 Tc-99 0.0276 CID (4 Pi) 1273..."6 Tc-99 Flat Surface 3/4" AfXJve Grnte 43-37 190949 Cs-137(Beta) 0.0387 CID (4 Pi) 127357 Cs-137(Beta)

Flat surface 3/4" f,JJove Grate Physical Checks Electronics CMcks As Founel As Ltfl outer Ptiys,cat Check* Pass H. hVotta e 900 Volts 1800Volts Tap Test Pass AU<!io Fooctlon Ched< Pass Calibration Date Set Pass Comments: calibrated with Ludlum 43-37 SIN 190949 IISllQ 20' C to C cable for wan and overhead set up.

Customer Equipment ID:

caIIbrated By N,cote WedIg OC Review By Matthew Hunter Atmospheric Cond LOnS - -*,nperature* 70 0 'F Humidity 24.0 "'* 83rome:nc Press

30 12 ""'1Q Date: Jan 3 I. 2024 Expires: Jan 31. 2025 oc Date Jan 31, 2024 In tolerance conditions 3111 b3sed on test res,Ats I> ino wrth.n si:,eclflod lim ts.. i!h no ro<lutbon by 1110 uncer1:11n1,, of lhe measurement ThlS c.,l1bratJon W3S performed bi RSC$ U$i"9 the fol'VNllO NIST Traceable sources Pulser 98756 * (Cll Due* OCI 31 2024)

'Jorl<ed on c.>l.br.loon: N COie Weotg The reponed axp:mcled oocert:11nty of measurement ts s:J:ed,s tnO s:>ndYcl unceru my or measurement TT1Jlt!l)iied by the cover:ioe f*ctor k such at lhe coverage prob3b, corresponds to app<<>'111\\31ely 95"'.

Unless o:her.,,se stated c:il bl'3uans performed In tonf01l'll3nce to tne lol10'~1ng documents AASI N323AB-2013; RSCS New Hampshire R3dlo:lc Materi31 LJcense Number 381R RSCS ca. bl'3tion seMCes are performed In a<eord:mce,-Ith Ille RSCS Rodla>on Protection Program M3nuaJ :md Sl3nd3rd Oper3br19 Proced res C;,l.bration L3l>of3to,Y Is operated 111 3ttord3nte..,111 ANS~ CSL 2540-1-1994.

RSCS. Inc h3s been,ssessed by ANAB *nd meets the ~~*ments of IS0/1:C 17025:2017 le demonstratJng tecl\\n cal competence.,

field of callbr3tion. Refer to the ScOl)e of Accredrt.:mon AC-2079 tor WormJtion on tile rJl)es of c.ii*brabons to whIth s aared!tation :,ppl.es.

Th*s cahbl'3tion certifJcate s II not be reproduced e,cept 111 full without the e, press wntten consent of RSCS Inc

~

S:11-,& Ccnd s.rva,, w:

a?LtdgtRox' klbocaNHOX:*

100,£~

l!ll1,*4-t"""J 1/1 t pj Survey Unit STR-101-01 Page 24 of32 Containment Vessel (CV) - 1st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record C.ilibra!lon Certificate - ID Number: 25035132000

~

cs Customer: Matthe G Hunter Radration Safety & Control Serv,ces, Inc.

93 Ledge Road Seabrook NH 0387 4 Testl I

Test2 I

5.00 kcpm I

4.99 kcpm I

Range TaroetValue AUTO 500 Kcpm#

AUTO 50 Kcpm#

AUTO 5Kcpm#

AUTO 0.5Krnm#

Instrument Ludlum MO<lel 3002 Probt Model Ludlum 43-93 Precision Check Test3 I

Mean 4.99 kcpm I

4.99 kcpm Accuracy Check As Found As Len 499Kcpm!I 499Kcpm#

50 Kcpm#

50 Kcpm~

5Kcpm#

5Kcpm#

0.498Kcpm#

0.498Kcpm#

Readings with

  • Ind cate ranges 11,'here As-Found readings are >20% of Target value Readings with " indicate As-left read ngs are >10% ol Target value.

Readings v.1th # 111dlcate ranges were calibrated using a pulser Serl.ii Number 25035132 Serial Number 42 1425 I

Results I

Pass Source ID Pulser 987 56 Pulser 98756 Pulser 98756 Pulser 98756 Probt Isotope Efflcitncy NIST Source ID G.omttry Comment 43-93 421425 Tc-99 43-93 421425 Cs-I37(Beta) 43-93 421425 Cs-137(Beta) 43-93 421425 Tc-99 43-93 421425 Cs-t37(Beta) 43-93 421425 Tc-99 43-93 421425 Cs-I37(Beta) 43-93 421-125 Tc-99 Physical Cheeks Light Check of Scmtllal!on Probes Pass Outer Physical Check: Pass Tap Test Pass Audio Function Cheek Pass Cord check Pass Calibration Date Set. Pass 0 0243 CID (4 Pl) 127356 Tc-99 0.0505 CID (4 Pl) 127357 Cs-I37(Beta) 0.0398 CID (4 Pi) 127357 Cs-I37(Beta) 0.0177 CID (4 Pl) 127356 Tc-99 0.1620 CID (4 Pl) 127357 Cs-137(Beta) 0.1108 CID (4 Pl) 127356 Tc-99 0.1193 CID (4 Pl) 127357 Cs-137(Beta) 0.0821 CID (4 Pl) 127356 Tc-99 Electronics Chtcks HI h Volt:l e Comments* Calibrated with 20' C to C cilble Customer Equipment ID:

Calibrated By Nicole Wedlg QC Review By Matthei Hunter Atmosp ric Cond :.ens -Temperature 71 1 *F f.umla.

36.0 "

  • 83rome:nc Pressure:30.29 IMlg.

Flat surface On Grate Flat SUrface On Grate Flat Surface 3/4" N>ove Grate Flat surface 3/4" N>ove Grate Flat surface on Contact Flat Surface On Contact Flat surface 3/4" Above Source Flat surface 3/4' Above Source As Found As Ltft 678 Volts 780 Volts Date: Mar 05. 202-1 Expires: Mar 05, 2025 QC Date* Mar 05, 2024 In toleraoce condrtJons are b.Jsed on tes; resu 13 iOll wrth,n specified rim :s wrth no reouctJon by lhe uncertainty ol lhe me3suremenL Unless o:herw*se stated Is cal bration "3S per1ormed b'/ RSCS 31 93 Ledge Rd Seabrook. NH u-.lbnQ the folloW no NIST Traceable sources PUiser 98756 - (C:ll Dile* 0c. 31 2024)

~otl<ed on cal.bra n: Nicole Wedlg The reported expanded 111certainty of measurement is s:a:ed 3s the S!.lnd3rd uncerumly or me3suren-<ml rrultiplied by the coveraoe f3ctor k such 1h31 the coverage prob3bl ity corresponds o :ippro M3le!y 95'16 Unless 0' erw:se Stiled C3lbralJonS performed m conform3nce to e lo 11-ing doCUIT'ents. MSI N323AB-2013; RSCS Ne-N Hamps ire R3dlOOCWl!

M.3:en3J I.Jeense Number l81R RSCS c3_11Jrn on serv1ce_s 3re performed in 3tcord:ince wrth !he RSCS R3d13~on Protection Prog~m M3nU31 ;md Stand3ro Operat1no Procedures RlcLJIICl'l~lc.:..-ct~,1nc

'-'3.ledge~ S..00...M-!Dlii"

!0015::~:33~

.~

. *7+-!':":S 111 t

Survey Unit STR-101 -01 Page 25 of32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record

~libration Certificate

  • 10 Number: 25035134000
  • 20240606
  • 1 RSCS Customer: Scott Ginter Radiation Safety & Control Services. Inc.

93 Ledge Road Seabrook NH 03874 Instrument Ludlum Model 3002 Probe Model Ludlum 43-93 Precision Check Serial Number 25035134 Serial Number 421368 Test!

I Tesl2 I

Test3 I

Mean I

Resuns 49.90 kcpm I

49.90 kcpm I

49.90 kcpm I

49.90 kcpm I

Accuracy Check Range Target Value As Found As Lett AUTO 500 Kcpm#

500 Kcpm#

500Kcpm#

AUTO 50 Kcpm#

49 9Kcpm#

49 9 Kcpm#

AUTO 5 Kcpm#

5 Kcpm#

AUTO 0.5Kcpm#

0.5 Kcpm#

Readings with

  • lnelIcate ranges Where As-Founel readings are >20% 01 Target value.

Readings with - inellcate As-left readings are > 10% of Target v.:ilue.

Readings with # indicate ranges were calibrated using a pulser Probe Isotope 43-93 421368 Cs-137(Beta) 43-93 42 1368 Tc-99 43-93 421368 Cs-137(Beta) 43-93 421368 Tc-99 43-93 42 I 368 Cs-I 37(Beta) 43-93 421368 Tc-99 43-93 421368 Cs-137 (Beta) 43-93 42 1368 Tc-99 Physical Checks light Check of SC1ntilati0n Probes* Pass Outer Physical Check: Pass Tap Test: Pass Audio Function Check. Pass Cord check Pass Efficiency 0 0158 CID (4 Pl) 0.0162 CID (4 Pi) 0.0 160 CID (4 Pi) 0 0055 CID (4 Pl) 0.1755 CID (4 Pl) 0.0975 CID (4 Pi) 0.1 238 CID (4 Pl) 0.0658 CID (4 Pi)

NIST Source 10 127357 Cs-137(Beta) 63963 (Beta) Tc-99 127357 Cs-I37 Beta) 127356 Tc-99 127357 cs-137(Beta) 127356 Tc-99 127357 Cs-137(Beta) 127356 Tc-99 Electronics Checks Hi h Volta e Comments: Ellioencles performed using 1 5" fiberglass grate as requested.

Customer Equ pment ID:

5 Kcpm#

0.5Kepm#

Geometry Flat Surface Flat surface Flat surface Flat surface Flat surface Flat surface Flat surface Flat Surface As Found 700 Vons Pass Source ID PuIser66*151 Pulser 66151 Pulser 66151 Pulser 66151 Comment On Grate On Grate 3/4" Above Grate 3/4" Above Grate On Contact On Contact 314* AbOve Source 314' Above Source As Left 700 Volts Calibrated By N cole Wedig QC Review By Matthew Hunter Date: Jun 06, 2024 Expires: Jun 06. 2025 QC Date Jun 06. 2024 Atmosp enc Cood :;ons

  • Temperature 71 O 'F. Humidity: 52.0 %. Barometnc Pressure:29.62 1n/hg.

In 1OIerance conditions are based on test results fa' lfl9 with n specified llm, s with no reduction by the uncertainty of the measurement The results contained herein relate only to e,em cahbrated Unless otherwse stated

  • is cal*bratlon was pertormed by RSCS at P3 Ledge Rd. Seabrook NH utilllJ!lg the fOIIO'.,,,ng NIST Traceable sources*

Pulser 66151 * (Cal Due: Apr05 2025)

Worl<ed on calibratoo: Chris Pirie\\ NlcOle Wed11 The reported expanded uncertainty of measuremem ls s:a~ as the s:andard uncertainty of measurement multiplied by the c.overage factor k such that the coverage prob:ibtfity corresponds o ~proximately 95'!6.

Unless othe/Wlse stated cal.llra:.ons performed in contorrronce to Ille fo110wIng documents: ANSI N323AB-20t 3: RSCS New Hampsture R3Clloacwe Material License Number 381 R. RSCS caobration services are performed,n accordance with tne RSCS Radia~on Protection Program Manual and Standard Operabno Procedures Cal bratlon Laboratory Is operated In accordance v,ilh ANSVNCSL Z..'40* t

  • 1994.

-Sn<yleai.dS.--m 731..-dgt Ro.liQ Sub'oot.NH 0JE74.

001 ~3-an, ri:n, *-4.67n Survey Unit STR-101-01 Containment Vessel (CV) - l st Level (Tanktop ), Starboard Side Page 26 of32

SAVANNAH Technical Staff Survey Unit Release Record Meter ID 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035132 25035134 25035134 25035134 25035134 NA 25035147 25035132 25035132 25035132 25035132 25035132 25035132 25035134 25035132 25035134 25035134 25035134 - Static Data Count Rate Total Weighted Eff Measurement ID (cpm)

(c/d)

STR-101-01-01 297 0.0858 STR-101-01-02 194 0.0858 STR-101-01-03 263 0.0858 STR-101-01-04 166 0.0858 STR-101-01-05 143 0.0858 STR-101-01-06 139 0.0858 STR-101-01-07 173 0.0858 STR-101-01-08 113 0.0858 STR-101-01-09 118 0.0858 STR-101-01-10 438 0.0858 STR-101-01-11 119 0.0858 STR-101-01-12 95 0.0858 STR-101-01-13 71 0.0858 STR-101-01-14 124 0.0858 STR-101-01-15 147 0.0858 STR-101-01-16-J 2000 0.0858 STR-101-01-17-J 219 0.0858 STR-101-01-18-J 84 0.0159 STR-101-01-19-J 141 0.0159 STR-101-01-20-J 93 0.0159 STR-101-01-21-J 207 0.0159 SA-01-01-J Not Used, See Section 6 SA-01-02-J 2230 0.1023 SA-01-03-J 128 0.0858 SA-01-04-J 1990 0.0858 SA-01-05-J 296 0.0858 SA-01-06-J 1750 0.0858 SA-01-07-J 906 0.0858 SA-01-08-J 2100 0.0858 SA-01-09-J 3470 0.0920 SA-01-10-J 1840 0.0858 SA-01-11-J 3100 0.0920 SA-01-12-J 1610 0.0920 STR-101-01-09-D 97 0.0920 Note: Meter IDs 25035132, 25035134 and 25035147 are connected to a Ludlum model 43-93 detector with an area of 100 cm2.

Survey Unit STR-101-01 Page 27 of32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record Date Scan ID 7/15/24 SA-01 7 /16/24 SA-01 7/16/24 SA-02-J - Scan Data Min/Max Range Meter ID (cpm) 25035113 200/1700 25035132 60/4000 25035134 67/219 rt Total Average Weighted (cpm)

Eff (c/d) 950 0.0802 2030 0.0632 143 0.0142 Note: Meter ID 25035113 is connected to a Ludlum model 43-37 detector with an area of 584 cm2. Meter IDs 25035132 and 25035134 are connected to a Ludlum model 43-93 detector with an area of 100 cm2.

Survey Unit STR-101-01 Page 28 of32 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

SAVANNAH Technical Staff Survey Unit Release Record J - - -- j_

,. t - Quality Control Assessment Measurement Initial measurement Replicate measurement Average Absolute Value of the difference Condition d m/100 cm2 Avera e < 52,300 Survey Unit STR-101-01 Absolute value of the difference 321.66 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side Value (dpm/100 cm2) 1376.00 1054.34 1215.17 321.66 Control Limit d m/100 cm2 11087.6 Result Pass Page 29 of32

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

STR-101-01-01 3463.3 t STR-101-01-02 2262.23 STR-101-01-03 3066.84 STR-101-01-04 1935.72 STR-101-01-05 1667.52 STR-101-01-06 1620.88 STR-101-01-07 2017.35 STR-101-01-08 1317.69 STR-101-01-09 1376.00 STR-101 t 0 5107.51 STR-101-01-1 t 1387.66 STR-101-01-12 1107.79 STR-101-01-13 827.93 STR-101-01-14 1445.96 S TR-t 0 I 15 1714.17 STR-101-01-16-J 23321.98 STR-101-01-17-J 2553.76 STR-101-01-18-J 5292.87 STR-101-01-19-J 8884.46 STR-101-01-20-J 5859.97 STR-t 01-01-21-J 13043.15 SA-01-02-J 21796.07 SA-01-03-J 1492.61 SA-01-04-J 23205.37 SA-01-05-J 3451.65 SA-01-06-J 20406.74 SA-01-07-J 10564.86 SA-01-08-J 24488.08 SA-01-09-J 37716.98 SA-01-10-J 21456.22 SA-01-11-J 33695.29 SA-01-12-J 17499.81 Parameter Survey Unit STR-101-01 Number of Measurements Number ofS+

Critical Value Meets I Doesn't Meet Acee tance Criteria DCGLw - Result (dpm/100 cm2) 66236.69 67437.77 66633.16 67764.28 68032.48 68079.12 67682.65 68382.31 68324.00 64592.49 68312.34 68592.21 68872.07 68254.04 67985.83 46378.02 67146.24 64407.13 60815.54 63840.03 56656.85 47903.93 68207.39 46494.63 66248.35 49293.26 59135.14 45211.92 3 t 983.02 48243.78 36004.71 52200.19 Result 32 32 21 Meets Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side j

Sign

+l

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SAVANNAH Technical Staff Survey Unit Release Record - Graphical Presentations Quantile Plot of Gross Activity Concentration 40300 35300

"/::. 30300 0

0 o 25300

--E

_g-20300

(.)

C: 15300 0 u

(.) 10300

<(

5300 300 * * * * * * * * * * * * *****

0%

10%

20%

30%

40%

50%

60%

70%

80%

Survey Unit STR-101-01 Containment Vessel (CV) - 1st Level (Tanktop ), Starboard Side rt 90%

100%

Page 31 of32

SAVANNAH Technical Staff Survey Unit Release Record Histogram Survey Unit Number:

STR-101-01 Containment Vessel (CV) - I st Level (Tanktop)

Survey Unit Name:

Starboard Side 20 18 16 14

>-.. 12

(.)

C:

Q) 10

u Q) ct

8 6

4 2

0 5439 10050 14661 19272 23884 28495 Upper end \\ alue (dpm/ I 00 cm2)

Survey Unit STR-101-01 Containment Vessel (CV) - I st Level (Tanktop ), Starboard Side

, J - - -- d rt 33106 37717 Page 32 of32

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