ML25164A221
| ML25164A221 | |
| Person / Time | |
|---|---|
| Site: | NS Savannah |
| Issue date: | 06/11/2025 |
| From: | Koehler E US Dept of Transportation, Maritime Admin |
| To: | Office of Nuclear Material Safety and Safeguards |
| References | |
| EPID L-2025-LRM-0075 | |
| Download: ML25164A221 (1) | |
Text
1 Nuclear Ship (NS) SAVANNAH Decommissioning (DECON) Project Pre-Submittal Meeting Final Status Survey Reports June 18, 2025 Office: Project Manager, NS SAVANNAH DECON (MAR-642)
Program Manager: Erhard W. Koehler, Senior Technical Advisor Date Issued: June 11, 2025
Current Decommissioning (DECON) Status The DECON project is in Phase III: License Termination Completed Milestones:
- NRC Confirmatory Surveys completed, July 2024.
- License Termination Plan (LTP) approved by NRC, January 2025.
- Final Status Surveys (FSS) completed, January 2025.
Upcoming Milestones:
- License termination anticipated: FY 2026.
- Final Demobilization and Vessel Redelivery: Approx. 6 months after LT
Project Background Project Background
- As described in MARADs PSDAR and LTP, the objective of this project is to terminate license NS-1 without restrictions, to permit disposition of the ship through any of the means available to MARAD. These include preservation, shipbreaking and artificial reefing.
- NSS is a National Historic Landmark, whose decommissioning and disposition are subject to consultation under the National Historic Preservation Act. The LTP contains detailed discussions of MARADs work to conform landmark protections to the NRC decommissioning requirements and license termination criteria.
- Significant structures have been preserved. The FSS campaign and resulting reports demonstrate that these preservation efforts comply with the license termination criteria.
Program Overview
- There are 69 survey units planned for submittal.
- The LTP originally had 76 survey units. During the NRC LTP review, 9 survey units were removed as recorded in the October 16, 2024 second round RAI response. These units covered systems that have been removed in their entirety.
- MARAD added survey units and subdivided other units during the development of survey plans.
- All units employed a combination of direct measurements and scans using standard hand-held detectors. 14 of the total also employed an In Situ Object Counting System (ISOCS).
FSS Program Overview
Report Overview
- Each report will summarize the results of the included Survey Unit Release Records (SURRs).
- The SURRs will be attachments to the report.
- SURRs provide detailed description of the survey design, survey results and data assessments.
FSS Report - Overview
Each report is structured as below. This presentation focuses on Report 1 of 5, and will describe each section in that context. Later slides provide a summary list of the contents for reports 2-5, a discussion of the exterior hull survey, and note those units which include ISOCS.
- Introduction
- Final Status Survey Program Overview
- Ship and Survey Unit Information
- Summary of Survey Results
- FSS Final Report Summary
- References
- Attachments (SURRs)
FSS Report - Structure
Purpose:
To provide a summary of the survey results and overall conclusions which demonstrate that portions of the Nuclear Ship SAVANNAH (NSS) meet the 25 mrem per year release criterion as established in 10 CFR 20.1402, Radiological Criteria for Unrestricted Use.
- To ensure that the NSS meets these requirements, MARAD has established an administrative limit of less than or equal to 15 mrem (0.15 mSv) per year of residual radioactivity that is distinguishable from background radiation results in a TEDE to an average member of the critical group. This administrative limit includes as low as reasonably achievable (ALARA) considerations.
FSS Report - Introduction
This section of the report discusses the following topics:
- Survey Planning
- Survey Design
- Survey Implementation
- Radiological Release Criteria
- Calibration Sources and Efficiencies
- Survey Data Assessment
- Quality Assurance and Quality Control Measures
- Technician Training
- Instrumentation
- Periodic Surveillance FSS Report - Program Overview
The Ship and Survey Unit Information section is broken down into two parts. The Ship Description section includes a short summary of the detailed description in the LTP.
FSS Report - Ship and Survey Unit Information
The Survey Unit Information section describes the units associated with each report. The following list is the survey units from Report 1.
Survey Unit Descriptions (All are Class 1):
STR-101-01 Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side STR-101-02 Containment Vessel (CV) - 1st Level (Tanktop), Port Side STR-102 Containment Vessel (CV) - 2nd Level (Flat)
STR-103 Containment Vessel (CV) - 3rd Level (D Deck)
STR-104 Containment Vessel (CV) - 4th Level (C Deck)
STR-105-01 Reactor Compartment - Lower Level (5-23) Starboard Half STR-105-02 Reactor Compartment - Lower Level (5-23) Port Half FSS Report - Ship and Survey Unit Information
Survey Unit Descriptions (All are Class 1, except as noted):
STR-105-03 Reactor Compartment - Lower Level (5-23) Drain Wells STR-108 Starboard Charging Pump Room STR-109 Auxiliary Access Trunk, C-Deck, Cold Water Chemistry Lab (Port) and Radiation Monitoring Room (Stbd)
STR-207 Health Physics Lab (Class 2)
STR-301 Navigation Bridge Deck - interior surfaces (Class 3)
SYS-112 Primary Pressurizer System (PE) including retained portions of the pressurizer SYS-117-01 Neutron Shield Tank wall located in the CV SYS-117-02 Fuel Transfer Tank wall located in the CV FSS Report - Ship and Survey Unit Information
Each report will include a graphical description of the location of its included survey units.
Big Picture of Report 1 Survey Unit Locations (14 of 15 are inside the red rectangle)
STR-301, Navigation Bridge Deck - interior surfaces (red oval)
STR-207, HP lab FSS Report - Ship and Survey Unit Information
Report 1 Big Picture - Containment, Reactor Compartment and Engine Room (Fr.99-148)
FSS Report - Ship and Survey Unit Information
Survey Unit Location: STR-101-01, Containment Vessel (CV) - 1st Level (Tanktop), Starboard Side Internal surfaces of the starboard side CV shell. Includes 1st-level deck and bulkheads up to the 14-foot elevation Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 2.05 mrem/yr Remediation: Four 3 ft by 1 ft areas. Applied peel away. Follow-up surveys < Operational DCGLW.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-101-02, Containment Vessel (CV) - 1st Level (Tanktop), Port Side Internal surfaces of the port side CV shell. Includes 1st-level deck and bulkheads up to the 14-foot elevation Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 1.12 mrem/yr Remediation: None. One survey triggered follow-up survey. Follow-up survey < Operational DCGLW.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-102, Containment Vessel (CV) - 2nd Level (Flat)
Internal surfaces of the CV shell bulkhead and deck/new fiberglass grating, Includes access to steam generator (U tube) manways and pressurizer heaters.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.88 mrem/yr Remediation: Two surveys triggered follow-up surveys. One additional required remediation by Masslinn cloth. Follow-up surveys < Operational DCGLW.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-103, Containment Vessel (CV) - 3rd Level (D Deck)
Internal surfaces of the CV shell bulkhead and deck/new fiberglass grating, Includes access to steam generator (steam side) manways, pressurizer and reactor coolant pumps.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.39 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-104, Containment Vessel (CV) - 2nd Level (C Deck)
Internal surfaces of the CV shell bulkhead and deck/new fiberglass grating, Includes access to reactor head, personnel hatch and equipment hatch.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 1.06 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-105-01, Reactor Compartment - Lower Level (5-23) Starboard Half Internal surfaces of the RC that extends from the Tanktop to above A-Deck. It contained reactor plant system components.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.12 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-105-02, Reactor Compartment - Lower Level (5-23) Port Half Internal surfaces of the RC that extends from the Tanktop to above A-Deck. It contained reactor plant system components.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.14 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-105-03, Reactor Compartment - Lower Level, Drain Wells There are two Drain wells in the RC lower Level.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.27 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-108, Starboard Charging Pump Room See red rectangle. The system supplied makeup water to the primary system and high-pressure water to seal control drives openings in the reactor vessel head.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.15 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-109, Auxiliary Access Trunk, C-Deck, Cold Water Chemistry Lab (Port) and Radiation Monitoring Room (Stbd) Decks A to C This area monitored water chemistry and air exhausted from the CV and RC. It included an equipment hatch to move material in and out of the RC lower level.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.10 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-207, Health Physics Lab The HP Laboratory was utilized primarily as a count room and for processing film badges. Records also indicate that decontamination of equipment was occasionally performed in the Health Physics Lab on A Deck.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.15 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: STR-301, Navigation Bridge Deck - interior surfaces The Navigation Bridge Deck contains the pilot house, gyro, radio and chart rooms. It also has fan rooms, battery rooms and an emergency generator room.
Results: 16 systematic random measurement locations, 2 judgmental measurement locations, 1 QC. 0.13 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: SYS-112, Primary Pressurizer System (PE) including retained portions of the pressurizer A manway was cut in the side of the pressurizer, all internal components were removed and a large section of the bottom that held the heaters was also removed. All that remains is the upper pressurizer shell and supporting skirt.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.42 mrem/yr Remediation: None. Two surveys triggered follow-up surveys. Follow-up surveys < Operational DCGLW.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: SYS-117-01, Neutron Shield Tank wall located in the CV The neutron shield tank was a primary shield filled with water that surrounded the reactor vessel. The survey unit consists of interior and exterior walls.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.37 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Survey Unit Location: SYS-117-02, Fuel Transfer Tank wall located in the CV The Fuel Transfer Tank surrounds the reactor vessel head above the hot legs. It was used to reduce dose during refueling.
Results: 15 systematic static measurement locations, 2 judgmental measurement locations, 1 QC. 0.15 mrem/yr Remediation: None. No investigation levels were triggered.
FSS Report 1 of 5 Summary of Survey Results
Derivation of the Gross Activity DCGLW
- Derivation of the Gross Activity DCGLW is presented in Chapter 6 of the LTP with details presented in LTP Reference 6-9, CR-139, Calculations to Support NS Savannah Surface Contamination DCGLs
- CR-139 established the basis for an initial suite of potential Radionuclides of Concern (ROC) for decommissioning which included 11 radionuclides such as C-14, Co-60, Ni-63, Sr-90, etc.
- They comprise 99.3% of the total activity. All other radionuclides are classified as Insignificant Dose Contributors.
Radionuclide Fraction of Total Activity Gross Activity DCGLW (dpm/100 cm2)
Co-60 1.63E-02 2.37E+04 Ni-63 9.00E-01 2.53E+08 Cs-137 7.61E-02 1.20E+05 Total 9.93E-01 NA FSS Report - Summary of Survey Results
Derivation of the Gross Activity DCGLW
- Ni-63 is a hard-to-detect (HTD) radionuclide. To account for Ni-63, the Easy-To-Detect (ETD) radionuclide Co-60 is used as a surrogate.
- The surrogate DCGL is computed as shown below
=
(:) +
Co-60 surrogate DCGLW = 2.37E + 04 2.53E+08 55.3 2.37+04 +2.53E+08 Co-60 surrogate DCGLW = 2.36E4 dpm/100 cm2 FSS Report - Summary of Survey Results
Derivation of the Gross Activity DCGLW
- The gross activity DCGLW is computed as shown below
=
1 1
1 +
2 2 +
1 1.76E1 2.36+04+ 8.241 1.20+05
= 6.97E+04 dpm/100 cm2 FSS Report - Summary of Survey Results
Investigation Levels
- It is a quality control check to determine when a measurement process begins to deviate from expected norms.
- It may indicate a failing instrument or an improper measurement.
- Operational DCGLw is 75% of the DCGLw (based on the MARAD 15 mrem administrative limit)
Survey Unit Classification For fixed measurements, perform investigation if:
For scan measurements, perform investigation if:
Class 1
> Operational DCGLW.
> Operational DCGLW Class 2
> Operational DCGLW
> Operational DCGLW Class 3
> 0.25 x Operational DCGLW
>0.25 x Operational DCGLW Systems and Components
> Operational DCGLW
> Operational DCGLW FSS Report - Summary of Survey Results
FSS Unit Number
- Systematic Measurements
- Random Measurements
- Judgmental Measurements
- Duplicate Measurements STR-101-01 15 0
17 1
STR-101-02 15 0
6 1
STR-102 15 0
2 1
STR-103 15 0
2 1
STR-104 15 0
2 1
STR-105-01 15 0
2 1
STR-105-02 15 0
2 1
STR-105-03 15 0
2 1
STR-108 15 0
2 1
STR-109 15 0
2 1
SYS-112 17 0
2 1
SYS-117-01 15 0
2 1
SYS-117-02 15 0
2 1
STR-207 15 0
2 1
STR-301 0
17 2
1 FSS Report 1 of 5 Final Report Summary Summary of Static Measurements
Parameter STR-101-01 STR-101-02 STR-102 STR-103 STR-104 Units Minimum Measurement 8.28E+02 1.08E+03 6.03E+02 5.73E+02 1.06E+03 dpm/100 cm2 Maximum Measurement 3.77E+04 2.45E+04 2.49E+04 9.20E+03 5.07E+04 dpm/100 cm2 Mean 9.53E+03 5.18E+03 4.07E+03 1.82E+03 4.91E+03 dpm/100 cm2 Median 3.46E+03 2.13E+03 8.54E+02 7.74E+02 1.35E+03 dpm/100 cm2 Standard Deviation 1.06E+04 5.96E+03 6.38E+03 2.52E+03 1.19E+04 dpm/100 cm2 Coefficient of Variation 1.12E+00 1.15E+00 1.57E+00 1.38E+00 2.42E+00 Unitless FSS Report 1 of 5 Final Report Summary Summary of Random and Static Measurement Parameters
Parameter STR-105-01 STR-105-02 STR-105-03 STR-108 STR-109 Units Minimum Measurement 2.87E+02 3.49E+02 5.09E+02 4.02E+02 3.55E+02 dpm/100 cm2 Maximum Measurement 1.15E+03 1.47E+03 3.93E+03 1.22E+03 5.61E+02 dpm/100 cm2 Mean 5.77E+02 6.31E+02 1.28E+03 7.00E+02 4.59E+02 dpm/100 cm2 Median 5.41E+02 4.97E+02 7.80E+02 6.53E+02 4.41E+02 dpm/100 cm2 Standard Deviation 1.89E+02 3.00E+02 1.08E+03 1.81E+02 6.93E+01 dpm/100 cm2 Coefficient of Variation 3.30E-01 4.80E-01 8.50E-01 2.60E-01 1.50E-01 Unitless FSS Report 1 of 5 Final Report Summary Summary of Random and Static Measurement Parameters
Parameter SYS-112 SYS-117-01 SYS-117-02 STR-207 STR-301 Units Minimum Measurement 2.52E+02 3.20E+02 8.83E+02 4.95E+02 3.72E+2 dpm/100 cm2 Maximum Measurement 2.92E+03 6.26E+03 1.85E+04 8.74E+02 1.04E+3 dpm/100 cm2 Mean 6.64E+02 1.72E+03 5.43E+03 6.84E+02 5.93E+2 dpm/100 cm2 Median 3.66E+02 1.10E+03 2.14E+03 6.59E+02 5.72E+2 dpm/100 cm2 Standard Deviation 6.91E+02 2.00E+03 5.92E+03 1.22E+02 1.28E+2 dpm/100 cm2 Coefficient of Variation 1.04E+00 1.16E+00 1.09E+00 1.80E-01 2.20E-1 Unitless FSS Report 1 of 5 Final Report Summary Summary of Random and Static Measurement Parameters
Survey Unit Dose Rate (mrem/yr)
STR-101-01 2.05 STR-101-02 1.12 STR-102 0.88 STR-103 0.39 STR-104 1.06 STR-105-01 0.12 STR-105-02 0.14 STR-105-03 0.27 STR-108 0.15 STR-109 0.10 SYS-112 0.42 SYS-117-01 0.37 SYS-117-02 1.17 STR-207 0.15 STR-301 0.13 The dose contribution from residual activity in each survey unit was calculated by taking the mean activity from the static measurements and dividing by the gross activity DCGL to derive a mean fraction.
The mean fraction was then multiplied by 15 mrem/yr (NSS administrative limit) to derive the dose from residual activity in the survey unit.
Residual Activity Dose Rates in Each Survey Unit FSS Report 1 of 5 Final Report Summary
Conclusions All fifteen survey units met the DQOs of the survey plans.
The survey units have been properly classified.
The maximum activity concentration measured of all the random and judgmental static measurements was 5.07E+04 dpm/100 cm2. This value is 72.7% of the gross activity DCGLW.
The sample data from all fifteen survey units passed the Sign test. The null hypothesis was rejected. Therefore, all fifteen survey units meet the release criteria.
The maximum dose contribution from residual activity in all fifteen survey units is 2.05 mrem/yr TEDE, based on the mean activity of measurements used for non-parametric statistical sampling.
No anomalous data was encountered as the result of the analysis of the collected data. Several elevated scan results and investigation levels were triggered resulting in investigations being performed as the result of the analysis of the collected data. Details are described in the report and in previous slides.
Isolation and Control procedures are implemented after FSS is complete.
All fifteen survey units are acceptable for unrestricted release.
FSS Report 1 of 5 Final Report Summary
Report Preparation Status as of June 11, 2025
- All fifteen SURRs have completed internal, independent and Safety Review Committee reviews.
- Planned submission is July 2025.
- MARAD will submit the report and all SURRs in hard copy to the document Control Desk -
as we have submitted all correspondence.
- To allow for more timely access by NRC staff, MARAD requests NRC consider allowing MARAD to upload the FSS Reports to the NRC Box.
FSS Report 1 of 5 Final Report Summary
Estimated submission: August 2025 MARAD does not plan for a pre-submittal meeting for reports 2 - 5.
STR-106 PORT Stabilizer Room STR-107 PORT Charging Pump Room STR-110 Gas Absorption Room STR-111 Cupola Inner Wall STR-202-01 RC - Mid Level - Decon Shower STR-205 STBD Stabilizer Room STR-206 Engine Room STR-208 Horseshoe STR-209 Hot Chem Lab STR-211 RC - Mid Level - 14' Flat STR-306 Promenade Deck - Exterior STR-313 Refrigerator Rooms and Passageways STR-316 Cargo Hold 4 - C Deck STR-317 Elevators and Shafts SYS-103 Soluble Poison Shutdown System (SP)
Future FSS Report - 2 of 5
Estimated submission: September 2025 The SURRs, in which the survey unit used the ISOCS as part of the survey design or to supplement the data collection and analysis, will include a separate attachment that describes ISOCS evaluation and the geometry to support the analysis.
STR-302 Bridge Deck - Exterior STR-303 Boat Deck - Interior STR-304 Boat Deck - Exterior STR-308 A Deck - Forward - Exterior STR-309 A Deck - Aft - Exterior STR-311 C Deck - Interior STR-312 D Deck - Various STR-314 Dry Stores and Stewards Stores STR-315 Cargo Hold 3 SYS-102 Emergency Cooling System (DK)
SYS-114-01 PD-T5 Equip Drain Tank - STBD SYS-114-02 PD-T6 Equip Drain Tank - PORT SYS-114-03 PD - Void Tank SYS-114-04 PD - Fresh Water Shield Tank SYS-118 Decommissioning HVAC Future FSS Report - 3 of 5
Includes only the 2019 Exterior Hull Surveys.
Note that MARAD previously presented on this topic on January 19th, 2022, during an LTP meeting with the NRC. These slides update that presentation.
FSS Unit Number MARSSIM Survey Unit Class Description of Hull Area Surveyed FSS-310A1 3
Starboard Fore FSS-311A1 3
Starboard Mid FSS-312A1 3
Starboard Aft FSS-313A1 3
Port Fore FSS-314A1 3
Port Mid FSS-315A1 3
Port Aft FSS-316A1 3
Starboard Above Boot Stripe FSS-317A1 3
Port Above Boot Stripe FSS-318A1 3
Rudder Future FSS Report - 4 of 5
Survey Unit Summary Future FSS Report - 4 of 5
Estimated submission: early October 2025 Notes:
- 1. These surveys were performed in 2019 during the last drydock availability at Philadelphia Ship Repair, LLC, (PSR) in Philadelphia, PA. This was the only time that the exterior hull was readily accessible to perform these surveys.
- 2. These surveys were performed following the methodology of an FSS, as described in the decommissioning activities guided by MARSSIM. They were not performed per the procedures that were later developed as part of the current decommissioning program.
- 3. All survey personnel followed the requirements of STS-003-001, Decommissioning Quality Assurance Program, STS-005-001, Radiation Protection Plan and STS-008-002, Health and Safety Plan.
- 4. Previous presentation suggested report CR-143 might be used as a release record; however, MARAD has instead prepared SURRs.
Future FSS Report - 4 of 5
Estimated submission: late October 2025 The SURRs, in which the survey unit used the ISOCS as part of the survey design or to supplement the data collection and analysis, will include a separate attachment that describes ISOCS evaluation and the geometry to support the analysis.
STR-201 RC - Mid Level - D Deck STR-202-00 RC - Mid Level - C Deck STR-203 RC - Upper Level - B Deck STR-204 RC - Upper Level - A Deck STR-210 Cargo Hold 4 - Tank Top STR-305 Promenade Deck - Interior STR-307 A Deck - Interior STR-310 B Deck - Interior SYS_STR-119 Penetrations SYS-106 Hydrogen Addition System (HA)
SYS-109 Intermediate Cooling System (CW)
SYS-116-01 Steam Generator - PORT SYS-116-02 Steam Generator - STBD STR-201 RC - Mid Level - D Deck STR-202-00 RC - Mid Level - C Deck Future FSS Report - 5 of 5
Questions?
POC - Erhard W. Koehler, MARAD.
(202) 680-2066 erhard.koehler@dot.gov