ML23243A863
| ML23243A863 | |
| Person / Time | |
|---|---|
| Site: | 99902091 |
| Issue date: | 09/26/2023 |
| From: | Amy Snyder Reactor Decommissioning Branch |
| To: | |
| Snyder, A, NMSS/RDB | |
| Shared Package | |
| ML23243B020 | List: |
| References | |
| EPID M-2023-INS-0000 | |
| Download: ML23243A863 (21) | |
Text
TECHNICAL EVALUATION REPORT RELATED TO THE RECOMMENDATION FOR THE SURFACE SHIP SUPPORT BARGE PROJECT FOR UNRESTRICTED RELEASE APPLYING NRC REGULATIONS
1.0 BACKGROUND
The Surface Ship Support Barge (SSSB) was a barge, (i.e., non-powered vessel) that was used to support refueling Navy nuclear-powered ships. The SSSB was originally the mid-section of the SS CANTIGNY, which was converted to a nuclear support facility and in 1964 was named the Prototype Waterborne Expended Fuel Container. Further repairs and alterations resulted in renaming the former mid-section to the SSSB. The SSSB was last used to support the final defueling of the Ex-ENTERPRISE in approximately 2016.
The SSSB is not an U.S. Nuclear Regulatory Commission (NRC) licensed or regulated facility or site. It is regulated under the separate authority of Naval Reactors (a joint Department of the Navy and the Department of Energy organization) as part of the U.S. Navy Nuclear Propulsion Program (NNPP). In September 2019, NRC entered into an interagency agreement (IA) with Naval Sea Systems Command (NAVSEA) to provide technical support the Navy regarding NAVSEAs oversight of the dismantlement and disposal of the SSSB consistent with NRC requirements (Agencywide Documents and Access and Management System (ADAMS)
Accession No. ML20177A172 Pkg).
The program for conducting NRC inspection activities1 for the SSSB is described in Inspection Manual Chapter (IMC) 2565, Regional Inspection Activities for Naval Reactors Naval Vessels Undergoing Decommissioning. IMC 2565 supports fulfillment of NRCs responsibility for providing oversight and inspection services of the SSSB as agreed in the above-mentioned IA between the NRC and NAVSEA. IMC 2561, Reactor Decommissioning Inspection Program and its associated procedures are also used, as appropriate.
NAVSEA selected APTIM Federal Services, LLC (APTIM) to decommission the SSSB. By contract, APTIM is required to perform dismantlement and disposal in compliance with all NRC licensee-applicable regulations. The Project Manager in NRC's Reactor Decommissioning Branch, Division of Decommissioning, Uranium Recovery, & Waste Programs (DUWP), Office of Nuclear Material Safety and Safeguards (NMSS) was designated as the official NRC point of contact with inspection support from the NRC Region I Office. NAVSEA approved the APTIM Federal Services, LLC, Decommissioning Work Plan - Surface Ship Support Barge Dismantlement and Disposal, Revision 1, referred to as the Decommissioning Work Plan (DWP) months after transfer of custody as APTIM was contracted to move the ship to Alabama from Virginia. NAVSEA decoupled the transfer of custody, from DWP approval, and restricted work to only supporting the tow and minor characterization work, until the DWP was approved (ML21144A145 Pkg). Based on NRC review and recommendation (ML21166A152) for approval of the DWP (ML21097A263, as supplemented ML21130A576), NAVSEA authorized transfer of custody of the SSSB to APTIM on June 10, 2021 (ML21166A150), to support dismantlement consistent with NRC regulations (ML21166A149 Pkg). The NRC concluded that APTIM's proposed SSSB DWP, as supplemented, establishes a program for dismantlement and decommissioning compliant with NRC regulations as required by the contract (ML21166A151).
1 NRC conducts these inspections consistent with NRC requirements as if the NRC licensed the SSSB project. NRC uses the term inspection in its conventional sense here to refer to NRC documentary and site evaluations to assess if APTIM is performing consistent with the DWP and NRC regulations and to refer issues to NNPP for any follow-up action, as appropriate.
ENCLOSURE Additionally, in the NRC recommendation letter (ML21166A152), the NRC noted that APTIM included five specific DWP commitments in its supplemental DWP that NRC would confirm during NRC reviews of decommissioning activities performed in accordance with the IA (see list in inspection report in Table 1). The commitments were associated with updating the DWP Radiological Constituents of Potential Concern (RCOPCs) following characterization sampling, confirming the RCOPCs address potentially significant radionuclides, confirming negligible tritium surface contamination dose contribution, monitoring effluents to confirm there is no groundwater or surface water contamination, and maintaining constant negative pressure ventilation in areas where loose or unpackaged contamination exists.
APTIM submitted its Surface Ship Support Barge Final Status Survey Plan, Revision 2 (FSS),
dated January 23, 2023 (ML23037A809). This revision clarified in Chapter 2.0 that release surveys of the containment structure (CS) (tent where segmentation occurred) will be based on the Multi-Agency Radiation Survey and Assessment of Materials and Equipment (MARSAME)
(ML090260577) using a Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM) type survey. Also, the revision clarified in Chapter 3.0, that the CS and associated ventilation system will be surveyed as a structure. The NRC requested additional information (RAIs) on February 3, 2023 (ML23037A854 Pkg). APTIM responses to the RAIs were submitted on February 9, 2023 (ML23193A521), and March 18, 2023 (ML23193A441). The NRC determined that these responses, as well as the clarification of the approach for the CS, were acceptable and had no further questions. Originally, the SSSB DWP stated that the CS would be left in place. APTIM was not able to leave the CS in place because the Shipyard would not allow such an action even though meeting the unrestricted release criteria. Through discussion with NRC, the NRC informed APTIM that it could either use MARSAME or MARSSIM type survey for the CS removal (ML23254A254). APTIM chose to use the MARSSIM type survey (ML23254A193).
The SSSB underwent dismantlement, radiological decommissioning that included final status surveys, site cleanup, and dismantlement activities. This technical evaluation report (TER) documents the NRCs rationale and conclusions for its recommendation to the NNPP regarding whether the SSSB decommissioning site would meet the NRC criteria for unrestricted release and NRC decommissioning requirements as if it were an NRC licensee, as identified in the Decommissioning Work Plan - Surface Ship Support Barge Dismantlement and Disposal, Rev.
2 (DWP), Attachment 7, SSSB Final Status Survey (FSS) Plan Summary (ML22151A118). The DWP was found to be acceptable to the NRC if APTIM were a licensee (ML21141A034 Pkg).
Specifically, the NRC reviewed the DWP for the conformity with the radiological criteria for license termination for unrestricted use provided in Title 10 of the Code of Federal Regulations (10 CFR) Part 20, Subpart E - Radiological Criteria for License Termination and specifically, 10 CFR 20.1402, Radiological Criteria for Unrestricted Use, which establishes the requirements for the release of a site for unrestricted use. The SSSB FSS Plan Summary (Attachment 7 of DWP) and Surface Ship Support Barge Final Status Survey Plan, Revision 2 (FSSP), dated January 23, 2023 (ML23037A809), as supplemented on February 9, 2023 (ML23193A616), and March 18, 2023 (ML23193A441) were reviewed by NRC inspectors and technical staff and were determined to conform to the DWP. The NRC inspectors reviewed FSS procedures for sample collection and radiological surveys and determined that they adequately implemented the revised FSS Plan.
2.0 EVALUATION The NRC staff considered the criteria for decommissioning in 10 CFR Part 20, Subpart E, Radiological Criteria for License Termination, in its evaluation. Further, under 10 CFR 20.1402, found in Subpart E, a site will be considered acceptable for unrestricted use if: (1) the residual radioactivity that is distinguishable from background radiation results in a total effective dose equivalent (TEDE) to an average member of the critical group that does not exceed 25 mrem per year; and (2) the residual radioactivity has been reduced to levels that are as low as reasonably achievable (ALARA).
The NRC will recommend SSSB project termination to the NNPP if it determines that (i) the remaining dismantlement has been performed in accordance with the approved DWP, and (ii) the final radiation survey and associated documentation demonstrate that the facility and site have met the criteria for decommissioning in 10 CFR Part 20.1402. The NRC staff will determine if the SSSB site meets these criteria and will make a recommendation to the NNPP regarding whether unrestricted release criteria has been met if the SSSB were a licensed site.
As described in Section 5.0 of the DWP, APTIM committed to follow its DWP and FSS Plan, for completing the remaining cleanup activities. The approved DWP is part of the contract between the NNPP and APTIM and becomes a requirement for unrestricted release and project termination. Section 5.0 of the DWP and Sections 2.0, Final Status Overview and Section 3.0, Survey Design of the FSS Plan describe the plan that encompasses the radiological assessment of all affected structures, systems, and land areas for the purpose of quantifying the concentrations of any residual activity that exists following all decontamination activities. APTIM implemented to completion all the actions as required by the DWP and FSS Plan.
In accordance with the SSSB FSS Plan Summary (Attachment 7 of DWP, Rev. 2 (ML22151A118)), dated May 29, 2022, and SSSB FSS Plan, Revision 2, dated January 23, 2023 (ML23037A809), as supplemented on February 9, 2023 (ML23193A440), and March 18, 2023 (ML23193A441), APTIM performed the SSSB FSSs for site release for unrestricted use in accordance with its DWP.
Under contract to the NRC, the Oak Ridge Institute for Science and Education (ORISE), as managed by Oak Ridge Associated Universities (ORAU), conducted a confirmatory radiological survey, during the weeks of April 25 and May 15, 2023, of selected areas of the site to be released. After the survey and data evaluation, ORISE provided its SSSB Final Confirmatory Survey Report (ML23269A057) to the NRC. The independent survey included gamma and beta radiation surveys and soil sampling. The ORISE results identified discrepancies that resulted in APTIM performing additional remediation in survey units 20A and 20B and resurveying those areas for FSS. However, the results of the ORISE surveys, combined with the ORISE laboratory analytical results of the soil samples and smears, provided confidence in APTIMs sampling and measurement methods for unrestricted release because the discrepancies are believed to be attributed to isolated human errors associated with scanning speed.
The NRC staff completed its evaluation of the Final Status Survey Reports (FSSRs) and documented its review in a separate technical evaluation report (Attachment to this TER). The following is the NRC staffs evaluation of all the submittals in which APTIM proposed that it has demonstrated the site meets the unrestricted release requirements and other decommissioning requirements for license termination of the project, if the SSSB were a licensed facility and APTIM were the licensee. The NRC staff completed its review and recommend unrestricted release of the site and termination of the project based on its evaluation.
2.1 Remaining Dismantlement Activities Section 5.0, Planned Decommissioning Activities of the DWP provided a discussion of the remaining dismantlement activities necessary for license termination. These activities include site remediation and radiological FSSs.
In the DWP, APTIM stated it planned to remediate the site, including structures, that remain on site, to the criteria specified in 10 CFR Part 20, Subpart E, for unrestricted use. To meet these criteria, APTIM planned to use typical remediation methods, which include wiping, washing, vacuuming, scabbling, spalling, and abrasive blasting. For radiologically contaminated systems and components, APTIM planned to either: (1) remove them and send them to an offsite processing facility, or to a low-level radioactive waste facility, for disposal; or (2) decontaminate them onsite and ensure that any residual radioactivity remaining meets the release criteria for unrestricted use.
As stated in the DWP, Section 5.0., Planned Decommissioning Activities, and as evaluated by the NRC staff through inspection and FSS review, all structures associated with SSSB were removed. At SSSB project completion, no structures will remain. The NRC confirmed this during the confirmatory surveys. Also, NRC stated that the security fence should remain until the NNPP determines that the SSSB site has met the unrestricted release criteria (ML23241A931).
APTIM stated verbally that the security fence will be removed after obtaining approval from NAVSEA.
APTIM detailed the results of its FSSs in FSSRs it submitted to the NRC staff. Refer to Table 2, APTIM Decommissioning FSSRs and Corresponding NRC FSSR Approvals for a complete listing of these decommissioning submittals and the NRCs review for acceptability with ADAMS Accession Nos. and document dates. The NRC staff has reviewed the licensees FSSRs for SSSB and concluded that APTIM has remediated the remaining structures, systems, and components consistent with DWP Sections 4.0, Dose Modeling, and 5.0, Planned Decommissioning Activities. Therefore, the NRC staff concludes that the dismantlement and decontamination activities have been completed in accordance with the DWP. In addition, all of the equipment was removed and was released for unrestricted use per the DWP.
APTIM performed MARSAME surveys per its DWP, Rev. 2. For completeness, a list of these surveys are provided as follows: ML22056A104, ML22056A072, ML22056A068, ML22041A410, and ML22039A277. For the MARSAME surveys, based upon the survey results and the data evaluation (i.e., all measurements were less than the specified ALs), the null hypothesis has been rejected and NRC concluded that the equipment could be released for unrestricted release with no additional radiological controls if SSSB were a licensed site. The NRC contracted ORISE to perform confirmatory surveys of the areas being considered for unrestricted release as described in NRC Inspection Report 2021001. The inspectors and technical staff at NRC headquarters reviewed ORISEs report titled Independent Confirmatory Survey Summary and Results for the U.S. Navy Surface Ship Support Barge Ballast Wing Tank 9 Port, Mobile, Alabama and APTIMs survey results for Ballast Wing Tanks 9 Port, Centerline, and Starboard to determine if the tanks met the criteria for free release. The ORISE report (ML22129A117) notes that ORISE did not identify any anomalous issues that would preclude the confirmatory data from Wing Tank 9 Port from demonstrating compliance with the unrestricted, free release criterion. The NRC staff agreed with this assessment.
2.2 Final Status Survey The FSS is the radiation survey performed after an area has been fully characterized, remediation has been completed, and the (usually) licensee believes that the area is ready to be released for unrestricted use. The purpose of the FSS is to demonstrate that the area meets the radiological criteria for unrestricted release.
Details of FSS results were submitted to the NRC in two separate FSSRs. Refer to Table 2, FSSRs and Corresponding NRC FSSR Evaluation, for a complete listing of these decommissioning submittals and the NRCs technical evaluation with ADAMS Accession Nos.
and document dates. The NRC concluded that all FSSRs would be acceptable if APTIM were a licensee because APTIM demonstrated that requirements of the SSSB FSS Plan, Revision 2, criteria were met.
The NRC conducted performance-based in-process inspections of APTIMs FSS Plan during the decommissioning process. The purpose of the inspections was to verify that the FSSs were being conducted in accordance with the DWP, and to evaluate the quality of the FSSs by reviewing the FSS procedures, methodology, equipment, surveyor training and qualifications, document quality control, and survey data supporting the FSSRs. The NRC inspectors documented their findings in inspection reports. Table 1, NRC Inspection Reports for SSSB on FSSs, provides the ADAMS Accession No. and document date for the relevant inspection reports.
In addition, the NRC conducted two independent confirmatory surveys to verify the FSS results obtained and reported by APTIM. During one of the confirmatory surveys, ORISE collected solid samples. These were analyzed and included in the confirmatory survey report. Two confirmatory surveys were performed but only one confirmatory survey report was developed covering both surveys. Refer to Table 3, Confirmatory Survey Report for Decommissioning, below, that references the confirmatory surveys performed with date and ADAMS Accession Nos. Confirmatory surveys consisted of surface scans for beta and gamma radiation, direct measurements for total beta activity, and collection of smear samples and soil samples for determining removable radioactivity levels.
Table 1, NRC Inspection Reports for SSSB on FSSs ADAMS Accession No.
Document Date Document Title ML23230A248 September 1, 2023 SURFACE SHIP SUPPORT BARGE - U. S. NUCLEAR REGULATORY COMMISSION INSPECTION REPORT NO.
99902091/2023001 ML22350A693 January 11, 2023 Surface Ship Support Barge - U.S. Nuclear Regulatory Commission Inspection Report No. 99902091/2022002 ML22146A101 May 27, 2022 Surface Ship Support Barge - U. S. Nuclear Regulatory Commission Inspection Report No. 99902091/2022001 ML22011A007 January 19, 2022 SURFACE SHIP SUPPORT BARGE - U. S. NUCLEAR REGULATORY COMMISSION INSPECTION REPORT NO.
99902091/2021001 The NRC staffs review of the all the FSSRs is documented in the Attachment to this TER and the survey units are referenced in Table 2, SSSB FSSRs and NRC Evaluation. APTIM submitted Phase I of the FSSR (ML23186A045), dated on July 3, 2023 and Phase II of the FSSR (ML23207A230), dated July 28, 2023.
Table 2, SSSB FSSRs and Corresponding NRC FSSR Evaluations FSS Report Decommissioning Work Plan -
Surface Ship Support Barge (SSSB)
Dismantlement and Disposal, Rev.
2 (DWP), Attachment 7, SSSB FSS Plan Summary (ML22151A118) and SSSB FSS Plan, Revision 2, dated January 23, 2023 (ML23037A809),
APPENDIX A, FSS SURVEY UNITS APTIM Submittal NRC
Response
1 SU-01 (paved)
SU-02 (paved)
SU-03 (paved)
SU-07 (paved)
SU-08 (paved)
SU-09 (paved)
SU-10 (paved)
SU-15 (paved)
SU-18A (non-paved)
SU-21 (non-paved)
APTIM Federal Services, LLC, FSS Report, Phase 1
- Surface Ship Support Barge Dismantlement and Disposal; Contract N00024-20-C-4139, dated July 3, 2023 (ML23186A045)
See TER Attachment 2
SU-04 (paved)
SU-05 (paved)
SU-06 (paved)
SU-11 (paved)
SU-12 (paved)
SU-13 (paved)
SU-14 (paved)
SU-16 (paved)
SU-17 (paved)
SU-18B (non-paved)
SU-19 (non-paved)
SU-20A (non-paved)
SU-20B (non-paved)
SU-22 (storm drains)
CS Ventilation Housing APTIM Federal Services, LLC, FSS Report, Phase 2
- Surface Ship Support Barge Dismantlement and Disposal; Contract N00024-20-C-4139, dated July 28, 2023 (ML23207A230).
See TER Attachment Under contract to the NRC, and at the request of the NRC, ORISE conducted two confirmatory radiological surveys of the area to be released the weeks of April 25 and May 15, 2023. The surveys included gamma, alpha, and beta radiation surveys and soil sampling. The results of the ORISE gamma, alpha, and beta radiation surveys, combined with the ORISE laboratory analytical results of the soil samples, satisfies the soil and surface activity derived concentration guideline levels (DCGL) described in the APTIM DWP. The report detailing these confirmatory survey activities is identified in Table 3, SSSB Confirmatory Survey Report for Decommissioning.
Table 3, SSSB Confirmatory Survey Report for Decommissioning ADAMS Accession No.
Document Date Document Title ML23269A057 September 2023 Independent Confirmatory Survey Summary and Results for SSSB Survey Units ML22129A117 April 29, 2022 Independent Confirmatory Survey Summary and Results for the U.S. Navy Surface Ship Barge Ballast Wing Tank 9, Port Mobile, Alabama Under 10 CFR 20.1402, found in Subpart E, a site will be considered acceptable for unrestricted use if: (1) the residual radioactivity that is distinguishable from background radiation results in a TEDE to an average member of the critical group that does not exceed 25 mrem per year; and (2) the residual radioactivity has been reduced to levels that are ALARA.
For this evaluation, the NRC staff used these criteria but slightly modified (DWP is used in the SSSB project as opposed to the term LTP) as follows because the SSSB is not a licensed facility and no part of the SSSB project site was formerly released for unrestricted release under a license:
The NRC will recommend termination of the SSSB project to the NNPP if it determines:
(1) dismantlement has been performed in accordance with the approved DWP; and (2) the final radiation survey and associated documentation, demonstrate that the facility and site have met the criteria for decommissioning in 10 CFR Part 20, Subpart E, if the facility were licensed. Under 10 CFR 20.1402, found in Subpart E, a site will be considered acceptable for unrestricted use if: (1) the residual radioactivity that is distinguishable from background radiation results in a TEDE to an average member of the critical group that does not exceed 25 mrem per year; and (2) the residual radioactivity has been reduced to levels that are ALARA.
APTIM met the NRC criteria for unrestricted release for the SSSB project.
As noted above, there were no partial site releases (PSRs) conducted for the SSSB project.
Therefore, the PSR approach discussed under, "For PSR and previous PSR interactions" in Appendix K, Section K.1.5, in the NUREG-1757, Vol 2, Rev.1, Consolidated Decommissioning Guidance, Characterization, Survey, and Determination of Radiological Criteria (ML063000252) was not used by the NRC to conduct its review for the SSSB decommissioning project.
APTIM decommissioned the SSSB site using NUREG 1575, Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM), Rev. 1 (ML003761445) approach, meaning that APTIM demonstrated compliance on a survey unit by survey unit basis. Under this method, the size of the survey units and the rigor of the surveys performed are determined based on the expected level of residual radioactivity in areas across the site as well as spatial and topographical considerations.
The NRC staff evaluation of the submittals listed in Table 2 above determined that future site inhabitants across all survey units would experience an average hypothetical future dose of less than 2 mrem/y. The maximum occurred for survey unit 17 which had a hypothetical future dose of 3.25 mrem/y based on the average gross beta activity measurements. To obtain these results in paved survey units, the NRC staff ratioed the average of systematic gross beta measurements to the adjusted DCGL of 5,300 dpm/100 cm2 and multiplied by 25 mrem/y, the potential dose basis for the adjusted gross DCGL derivation. In soil survey units, the NRC staff calculated the sum-of-fractions (SOF) value from the average RCOPC concentrations in systematic samples (average value of each RCOPC divided by the applicable DCGL with negative averages set to zero) and multiplied it by 25 mrem/y which is the potential dose basis for the DCGLs. Based on cleanup activities carried out by APTIM for decommissioning; the NRC staffs review of APTIMs Decommissioning FSSRs; and the results of ORISE confirmatory surveys for Decommissioning, conducted under contract with the NRC, the NRC staff concludes that the SSSB site would meet the criteria of 10 CFR 20.1402 for decommissioning activities if it were a licensed site.
The NRC considered the final dose from for the entire site. In this case, the site is defined as the entire SSSB project site. In applying the sum of the fractions approach, described in detail in NUREG-1757, Vol 2, Rev.2 (ML22194A859), the actual cleanup values demonstrated that the potential dose from all residual radioactivity at the SSSB site from all media is less than 25 millirem per year. Thus, the NRC staff concludes that the entire SSSB project site is below the NRC release criteria for unrestricted use of less than 25 mrem/year plus ALARA.
NUREG-1757, Vol. 2, Rev. 2, Consolidated Decommissioning Guidance Characterization, Survey, and Determination of Radiological Criteria (ADAMS Accession No. ML22194A859),
provides guidance regarding ALARA. This guidance states that in light of the conservatism in the building surface and surface soil generic screening levels developed by NRC staff, the NRC staff presumes, absent information to the contrary, that licensees who remediate building surfaces or soil to the generic screening levels do not need to provide analyses to demonstrate that these screening levels are ALARA. In addition, both the Statements of Consideration for Subpart E and the Final Generic Impact Statement (NUREG-1496) provide that an ALARA analysis for unrestricted release of soil need not be done. The NRC agrees with APTIMs February 9, 2023, response (ML23193A521) to RAI 2 (ML23037A864) that shows that APTIM used these screening levels and meets ALARA requirements because APTIM followed the guidance as specified in Appendix N, ALARA Analyses, of NUREG-1757 Vol. 2, Rev 2.
This TER does not evaluate non-radiological constituents. However, the FSSRs did include non-radiological constituents. These assessment are found in Section 6.5.2 of each of the FSSRs (Phase I of the FSSR (ML23186A045), dated on July 3, 2023 and Phase II of the FSSR (ML23207A230), dated July 28, 2023). APTIM removed all SSSB structures and components, as specified in its DWP, Rev. 2, and disposed of them as radioactive waste in accordance with Table 3-1, Structural Areas and Table 3-2, Vessel Systems in the DWP.
Therefore, based on the above discussion, the NRC staff concludes that the entire SSSB project site, meets the requirements of 10 CFR 20.1402. If the SSSB site were licensed, it would be considered acceptable for unrestricted use because the residual radioactivity that is distinguishable from the background radiation results in a total TEDE to an average member of the critical group that does not exceed 25 mrem/y, and the residual radioactivity has been reduced to levels that are ALARA.
2.3 Other Documents Required for License Termination In addition to the license termination requirements of 10 CFR Part 50, Part 30, 40, and 70, licensees also have requirements for forwarding of specific records to NRC prior to license termination. In this case, APTIM is not a licensee, but the in the DWP, similar records were required to be addressed. Table 4, Record Forwarding Requirements, summarizes these requirements.
Table 4, Record Forwarding Requirements 10 CFR 30.51(d)
By product material Associated with producing Special Nuclear Material Prior to license termination, each licensee authorized to possess radioactive material with a half-life greater than 120 days, in an unsealed form, shall forward the following records to the appropriate NRC Regional Office:
(1) Records of disposal of licensed material made under 10 CFR 20.2002 (including burials authorized before January 28, 1981),
20.2003, 20.2004, 20.2005; and (2) Records required by 10 CFR 20.2103(b)(4).
Prior to license termination, each licensee shall forward the records required by 10 CFR 30.35(g) to the appropriate NRC Regional Office.
Prior to license termination, each licensee authorized to possess source material, in an unsealed form, shall forward the following records to the appropriate NRC Regional Office:
(1) Records of disposal of licensed material made under 10 CFR 20.2002 (including burials authorized before January 28, 1981),
20.2003, 20.2004, 20.2005; and (2) Records required by 10 CFR 20.2103(b)(4).
(Receipt, transfer, and disposal source of biproduct material)
Prior to license termination, each licensee shall forward the records required by 10 CFR 40.36(f) to the appropriate NRC Regional Office.
(Records of the results of measurements and calculations used to evaluate the release of radioactive effluents to the environment. This includes those records of the results of measurements and calculations used to evaluate the release of radioactive Before license termination, licensees shall forward the following records to the appropriate NRC Regional Office:
(1) Records of disposal of licensed material made under 10 CFR 20.2002 (including burials authorized before January 28, 1981),
20.2003, 20.2004, 20.2005; and (2) Records required by 10 CFR 20.2103(b)(4); and (3) Records required by 10 CFR 70.25(g).
effluents to the environment required under the standards for protection against radiation in effect prior to January 1, 1994.)
For the SSSB project, APTIM did not dispose of licensed material under 10 CFR 20.2002.
Also, APTIM has not disposed of any licensed material under 10 CFR 20.2003, 20.2004, or 20.2005. Therefore, records of such disposals do not exist because these types of disposals were never made for the SSSB project through the NRC. APTIM followed its Waste Management Plan located in Chapter 9 of its DWP, Rev. 2 (ML22151A118) which is consistent with 10 CFR 20.2006.
Based on the information above, NRC considers APTIM's submittals to be consistent with the record forwarding requirements in 10 CFR 30.51(d)(1), 10 CFR 40.61(d)(1), and 10 CFR 70.51(a)(1) in support of SSSB project unrestricted release.
Section 20.2103(b)(4) addresses records associated with the release of radioactive effluents to the environment. There were no point sources of effluent discharges from the SSSB site. As discussed in Attachment 3 to the DWP, SSSB Project Environmental Monitoring Plan, (ML22151A118) thermoluminescent dosimeter (TLDs) or optically stimulated luminescence devices (OSLs) would be used to monitor direct exposure at the site perimeter fencing and air samplers were established at roughly each compass point along the site fencing during the dismantlement work as preliminarily shown in Appendix A to Attachment 3 of the DWP.
The NRC staff note that APTIM submitted on July 13, 2023 (ML23222A073 Pkg) a spreadsheet with all the Environmental Monitoring data and trending over the course of the project and the 2023 Public Dose assessment (ML23222A082) for the end of the project. The NRC staff notes that there were no impacts to the environment due to the SSSB project. Further, on June 22 (ML23223A031) and July 6, 2023 (ML23222A074), APTIM provided documentation showing that all waste has been removed from the SSSB site.
With the last waste shipment, and all the previous environmental trending and waste disposal information, as noted above, the NRC staff conclude that the decommissioning record associated with the release of effluents to the environment would be complete if the SSSB were a licensed facility.
With these submittals, NRC concludes that APTIM for the SSSB project would have met all the requirements of 10 CFR 30.51(d)(2), 10 CFR 40.61(d)(2), and 10 CFR 70.51(a)(2) if it were a licensee.
Due to the similarity of the requirements, APTIM would have also addressed the requirements of 10 CFR 30.51(f), 10 CFR 40.61(f), and 10 CFR 70.51(a)(3), collectively, if it were a licensee.
These regulations require the licensee to forward information important to decommissioning as required by paragraphs (1), (2), (3), and (4) of 10 CFR 30.35(g), 10 CFR 40.36(f), and 10 CFR 70.25(g), respectively. NRC concludes that APTIM would have met these requirements, if it were a licensee, through the submittal of: (1) SSSB DWP, revisions and information incorporated therein; (2) SSSB Characterization reports of which the results were summarized in the DWP; (3) APTIM SSSB FSSRs, and (4) other information environmental and waste documentation, as noted above.
Based on the above information, the NRC concludes that APTIM would have met the requirements of 10 CFR Parts 30, 40, and 70 for forwarding of specific records to NRC prior to license termination, if APTIM were a licensee.
Other Records of Note For completeness for the project decommissioning files, the NRC staff notes (ML23251A128) that for 2021 there were no measurable dose received by anyone. For 2022, the project dose was 727 mrem with a maximum individual dose of 151 mrem. For 2023, first quarter, the project dose was 47 mrem with a maximum individual dose of 24 mrem/yr. Overall, the project dose from beginning to end was 774 (727 + 47) mrem with a max individual dose of 175 mrem. Also, A total of 17 individuals received measurable dose on the project. Only one had more than 100 mrem. The reported results would demonstrate if the SSSB site were licensed, that the decommissioning occupational dose meet the requirements in 10 CFR part 20, Standards for Protection Against Radiation.
3.0 STATE INTERACTION The NRC and the State of Alabama held monthly SSSB status calls covering approximately the duration of SSSB decommissioning project. This TER was prepared by the NRC staff without input from the State of Alabama. On September 11, 2023, the NRC staff notified the State of Alabama for awareness that the NRC was near completion of its review and estimates that it would provide its recommendation to the NNPP on whether APTIM meet the unrestricted release criteria terminate the SSSB project (ML23255A203) by the end of September 2023.
4.0 ENVIRONMENTAL CONSIDERATION
S NAVSEA approved the DWP months after transfer of custody as APTIM was contracted to move the ship to Alabama from Virginia. NAVSEA decoupled the transfer of custody, from DWP approval, and restricted work to only supporting the tow and minor characterization work, until the DWP was approved (ML21144A145 Pkg). In a letter dated May 11, 2021 (ML21144A148)
APTIM requested to commence the open-ocean transit of the SSSB to Mobile, AL prior to approval of the DWP. After completing the transit, APTIM said it would off-load the SSSB onto land at the decommissioning site but will not commence any decommissioning work until the DWP is approved. On May 14, 2021, NAVSEA approved (ML21144A147) the APTIM request, based on the NRC environmental review documented in the NRC March 17, 2021 letter (ML21061A108) and the NAVSEA evaluation (ML21134A201).
As documented in the Surface Ship Support Barge - Memorandum for the Record regarding Categorical Exclusion of Barge Transfer for Dismantlement and Disposal, under the terms of the NAVSEA-NRC agreement, the NRC reviewed the DWP for compliance with NRC regulations and provided NAVSEA with an environmental analysis that NAVSEA can use in consideration of its responsibilities under the National Environmental Policy Act (NEPA).
NRC concluded that decommissioning of the SSSB will have no significant impact on the environment. Specifically, the NRC concluded that decommissioning of the SSSB, as described in the DWP, would involve no significant hazards consideration, no significant increase in the amounts, and no significant change in the types of any effluents that may be released offsite, and no significant increase in individual or cumulative occupational radiation exposure. Based upon the NRC review, the NRC staff recommended that a simple environmental assessment (or categorical exclusion, as applicable) would appropriately capture the potential environmental impacts of this decommissioning action. The NRC evaluation report (ML21134A200 Pkg) was provided to the NAVSEA. NAVSEA concurred with the NRC conclusion and noted that transfer of vessels for decommissioning is eligible for categorical exclusion under 32 CFR 775.6(f)(11) and decommissioning of vessels is eligible for categorical exclusion under 32 CFR 775.6(f)(21). NAVSEAs memorandum for the record (ML21134A202) documents the decision, based upon the environmental review provided by the NRC and the lack of extraordinary circumstances under 32 CFR 775.6(e),
to categorically exclude decommissioning and disposal of the SSSB from further analysis under NEPA.
NRCs recommendation that SSSB project met the criteria for unrestricted release and NAVSEAs decision on whether to agree with the NRC recommendation does not require further environmental evaluation. License termination or PSR under unrestricted release is not an action that requires an amendment to the license and therefore no further NEPA evaluation would be required. If SSSB were licensed, the termination of the SSSB license would not require an amendment.
5.0 EVALUATION OF THE NEED FOR NRC/ENVIRONMENTAL PROTECTION AGENCY (EPA) LEVEL 2 CONSULTATION
5.1 Background
The NRC and U.S. EPA entered into a Memorandum of Understanding (MOU) for Consultation and Finality on Decommissioning and Decontamination of Contaminated Sites on October 9, 2002 (ML20177A172 Pkg). The MOU provides that, unless an NRC licensed site exceeds any of three trigger criteria contained in the MOU, the EPA agrees to a policy of deferral to the NRC for decision making on decommissioning, without the need for consultation.
For sites that trigger the criteria in the MOU, the NRC will consult with the EPA at two points in the decommissioning process: (1) prior to NRC approval of the licensees LTP or Decommissioning Plan, which the NRC terms Level 1 consultation; and (2) following completion of the FSS, which the NRC terms Level 2 consultation. SSSB is not an NRC licensed facility.
However, the NRC compared the FSSR against the EPA-NRC criteria (ML022830208) for completeness, as if the SSSB were a licensed facility, and concludes that a consultation would not be needed either a Level 1 nor Level 2 consultation because concentrations of contaminants of concerns did not trigger the EPA-NRC criteria in the MOU, Even though the SSSB site is an industrial site, it met the screen criteria for the most restrictive scenario (the residential scenario) for unrestricted release.
The SSSB site is not a licensed site and the EPA MOU noted above is not applicable. However, for completeness, the NRC staff evaluated the SSSB results against the trigger levels as if it were a licensee.
5.2 Evaluation The unrestricted release was completed in accordance with the SSSB DWP and NRC decommissioning requirements which requires the evaluation of the FSSRs, among other things, as part of the project completion process. Based on the NRC staffs recommendation of approval of the FSSRs, the NRC staff determined that each FSSR demonstrates that each of the SSSB survey units is acceptable to release for unrestricted use in accordance with, Radiological Criteria for License Termination, of Part 20, Standards for Protection Against Radiation, to Title 10 of the Code of Federal Regulations (10 CFR), Subpart E for unrestricted release, if the SSSB were a licensed facility. FSSR evaluation for SSSB survey units are found in Attachment A.
The above-mentioned NRC-EPA MOU provides that, unless an NRC licensed site exceeds any of three trigger criteria, the EPA agrees to a policy of deferral to NRC decision making on decommissioning, without the need for consultation. For sites that trigger the criteria in the MOU, the NRC will consult with the EPA at two points in the decommissioning process:
(1) prior to NRC approval of the LTP or Decommissioning Plan, which the NRC terms Level 1 consultation; and (2) following completion of the FSS, which the NRC terms Level 2 consultation.
Following completion of the review and approval of the SSSB FSSRs, the NRC staff evaluated the FSS measurements to determine whether they would trigger the need for a Level 2 consultation. Based on this evaluation, the NRC staff concluded that a Level 2 consultation would not be needed if APTIM held an NRC license because the average concentration (calculated from final status survey data) of each radionuclide of concern within each survey unit in all FSSRs is below the values set forth in Table 1 of the MOU and, when applying the SOF approach, described above (in footnote 4), the SOF is significantly below unity for every survey unit. Therefore, the site would not have required a Level 2 consultation. It also would not have met the other triggers in the MOU.
6.0 CONCLUSION
The NRC staff concludes, based on the considerations discussed above, that: (i) the remaining SSSB dismantlement was performed in accordance with the DWP, (ii) the SSSB FSSs and associated documentation, including an assessment of dose contributions, demonstrate that the facility and site have met the criteria for decommissioning in 10 CFR part 20, Subpart E, if the SSSB were a licensed facility and (iii) the Navys contractor conducting the SSSB project, APTIM, met the requirements for forwarding of specific records to NRC prior to project completion, if APTIM were a licensee. The NRC concludes that APTIM was consistent with the requirements for termination of the SSSB project as stated in 10 CFR 50.82(a)(11) and recommends that NAVSEA approve the unrestricted release of the SSSB project site.
Principal Contributors:
A. Snyder, Senior Project Manager, DUWP/RDB G. Chapman, Health Physicist, CHP, DUWP/RDB K. Pinkston, Risk Analyst, PhD, DUWP/RTAB Date:
September 26, 2023
ATTACHMENT:
TECHNICAL EVALUATION BY OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS RELATED TO FINAL STATUS SURVEYS FOR SURFACE SHIP SUPPORT BARGE DOCKET NO. 99902091
1.0 INTRODUCTION
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed Final Status Survey Reports (FSSRs) for twenty-nine surveys encompassing the land areas (paved and unpaved) and structures at the Surface Ship Support Barge (SSSB) site as submitted by letters dated July 3, 2023 (Agencywide Documents ADAMS Accession No. ML23186A045) and as submitted by letter dated July 28, 2023 (ML23207A230). These surveys detailed the results of twenty-nine final status surveys (FSSs) that generally followed the previously approved survey plan (ML22151A118). The survey plan called for scanning, and direct measurement or sampling consistent with NUREG 1575, Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM), Rev.1 (ML003761445) methods.
The criteria for unrestricted release was that associated with the screening criteria in NUREG-1757, Vol 1, Rev. 1, Consolidated Decommissioning Guidance: Decommissioning Process for Materials Licensees, Appendix B, Screening Values. The radionuclides of concern (ROCs) for the surveys were Co-60, H-3, C-14, and Ni-63, with Co-60 being the primary ROC which would serve as a surrogate for other hard-to-detect ROCs when performing beta/gamma survey measurements. Soil or sediment samples were analyzed for all ROCs. In addition, APTIM, the Navys contractor, had an ALARA goal that it would strive to ensure that residual radioactivity was not significantly elevated above that indicated during baseline surveys.
The site is that area contained within the Alabama Shipyard in Mobile, AL where the SSSB was placed to facilitate its decommissioning and shipment as waste materials. The area, most of which was fenced off to provide access control, was primarily paved although some portions were unpaved. A containment structure (CS) was constructed over a portion of the fenced area which is where most of the sectioning work of the SSSB occurred. The CS was present at the time of the FSS surveys and included as a survey unit as was the ventilation housing unit servicing the CS and the storm drains located on the site. The structure itself was of metal frame with fabric lining on the interior and exterior of the frame; the interior lining material was removed before the FSS. The surface soil inside the CS was removed to at least 6 below grade, in some areas significantly more soil was removed. The CS FSS results were reviewed by the NRC and then the CS was removed from the site. Once the NRC and Naval Sea Systems Command (NAVSEA) accept and verify/approve the remaining FSSRs, it is expected that the remaining security fence will be removed, and the soil areas will be brought up to grade with materials brought in from offsite before the site is released for unrestricted use.
Initially, APTIM, the contractor performing the SSSB decommissioning work, estimated that 22 survey units, as well as the storm drains, would be surveyed. However, the plans changed from the initial estimate due to the phasing approach of the surveys and because physical features of the site made it more practical to further segment the survey units from what was originally planned. The classification of the survey units was not relaxed from what was initially discussed in the survey plan. The NRC staffs analysis of the surveys performed is provided below.
2.0 EVALUATION APTIM provided data summaries of each survey unit in the documents submitted. The NRC staff reviewed the data summaries, as well as the data reported for each survey, and compiled a table of the most relevant information (see Attachment 1. Summary of Final Status Surveys for 29 Survey Units). The NRC staff noted that the survey unit areas were compliant with the size guidance for the survey unit classifications in MARSSIM. Those survey units for which no area was provided were considered adequate because they were either a Class 3 survey unit with unlimited size restrictions or were of minimal size concern such as being a relatively small ventilation housing unit, accessible portions of drains, etc. As may be seen from the tables, all surveys were stated as meeting the release criteria (i.e., < 25 mrem/y hypothetical dose).
Compliance was established primarily by inspection of the survey data as no datum was greater than half of its respective DCGL. The dose estimated in the table was calculated by NRC staff and typically reflects rounding of the calculated sum of fraction (SOF) values to 2 significant digits. All survey unit hypothetical dose estimates were less than 4 mrem/y with the highest hypothetical dose being estimated for survey unit 17 (3.25 mrem/y). No elevated areas of measurements exceeding the DCGLw (DCGLs for average concentrations over large areas) or a sample specific SOF greater than unity were identified in any survey unit.
The NRC staff reviewed the box and whisker plots of the gamma walkover surveys conducted over each paved or unpaved survey unit with 80-100% coverage. The NRC staff noted that results of scans during the FSSs were generally similar to the baseline surveys for each survey unit although it appears that more variability in data was present at the time of FSS. A statistical evaluation would be necessary to demonstrate whether the datasets were significantly different, which is not the traditional purpose of the scanning surveys but rather to identify elevations in gamma radiation fluence that need to be further investigated, usually through biased measurements or samples. The NRC staff also reviewed the post plots of the walkover surveys and noted that adequate effort was made to scan appropriate portions of the site consistent with MARSSIM guidance. It was also noted that the results of the surveys, as indicated in the box and whisker plots, were generally not indicative of the presence of significant areas of contamination which would be indicated if outliers were present at much higher values than was present during baseline surveys. APTIM performed walkover gamma surveys consistent with MARSSIM general guidance which has a tabulated sensitivity of 3.4 pCi/g for Co-60, which is less than the screening value of 3.8 pCi/g and was considered adequate for the surveys. APTIM notes that actual background at the site is much lower than assumed in the MARSSIM guidance so that actual sensitivity should be 2 pCi/g Co-60 or better. The scanning sensitivity is discussed further in the confirmatory survey section of this report.
Similarly, the NRC staff reviewed the box and whisker plots of the beta walkover surveys that were conducted so that coverage was achieved approximating 10% for Class 3 survey units, 25% for Class 2 survey units, and 100% for Class 1 paved survey units. The NRC staff noted that the plots indicated higher beta scanning results during FSS than were present during baseline surveys for each survey unit for which baseline surveys were conducted. APTIM noted that this may have been because the detector was located higher from the ground during the baseline surveys. Regardless, the magnitude of measurements did not even exceed half of the screening limit of 5,300 dpm/100 cm2 indicating that no significant beta contamination is likely present that could exceed the release criteria.
Similar to above, APTIM made box and whisker plots of the direct beta measurements taken in the various non-soil survey units. All measurements were significantly less than the 5,300 dpm/100 cm2 screening limit with the highest measurement (taken in the storm drains) being less than 1/3rd of the limit. Interestingly, the FSS survey measurements were generally less, on average, than the baseline measurements in those survey units for which baseline measurements were taken. APTIM states that this is likely due to Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) present in blasting grit which was present to some degree across much of the site prior to the SSSB being brought to the Alabama Shipyard. Much of the area was cleaned/swept of debris and rocks prior to the scanning/direct measurement surveys to minimize the potential for damage to the instrumentation. Summaries of the direct measurements were presented in Appendix F of the submittals.
Removable activity (smears) were collected at each direct measurement location consisting of one smear each for gross alpha/beta, tritium, C-14, and Ni-63 analyses. APTIM provided summaries of the results in Appendixes F and G of its submittals. Detectable activity greater than the Minimum Detectable Concentration (MDC) was not found for gross alpha/beta smears.
Isotopic analyses of hard-to-detect (HTD) smears identified concentrations greater than the Minimum Detectable Activity (MDA) infrequently across the site except for the CS where results greater than the MDC for H-3 and Ni-63 became significantly more frequent. All reported results greater than the MDCs were several orders of magnitude less than the applicable DCGLw for the identified radionuclides. Also, the positive results, even if less than the MDC, for gross alpha/beta activity were generally consistent with screening modeling assumptions that less than 10% removable activity was present. There is no direct criteria applicable to removable activity as the DCGLw for direct measurement applies to the total beta activity measurements previously discussed and the screening criteria has an assumption that 10% of the total activity measured is due to removable activity.
Soil and sediment samples were collected from the unpaved survey units (i.e., SU18A, SU18B, SU19, SU20A, SU20B, and SU21) as well as SU22 (storm drains). Samples were analyzed for all four ROCs with the results summarized in Appendix I of the submittals. While there were infrequent detects above the MDC for Ni-63 and Co-60 across the site, only 1 detection exceeded 1 pCi/g (1.04 pCi/g in a biased sample), and most were only slightly greater than the MDC. An exception to this was in survey units 20A and 20B which were inside the CS footprint.
In these survey units, relatively frequent Co-60 detects above the MDC occurred although, again, the detectable concentrations were less than 1 pCi/g, except for the one biased sample in survey unit 20B previously referred to, and did not approach the DCGLw of 3.8 pCi/g. The NRC staff noted that the a posteriori evaluation of relative shift in unpaved areas performed by APTIM (Table 6-6 of the submittals and related text) stated that it indicated not enough samples were collected. The NRC staff performed a similar evaluation utilizing the reported sample analytical data and determined a relative shift much greater than what was actually used by APTIM during survey planning could have been applicable, demonstrating that an adequate number of samples were obtained. This discrepancy is likely because APTIM based its evaluation on the walkover survey data while NRC staff utilized the reported sample analytical data which staff believe to be more applicable.
The NRC staff note that the CS and ventilation housing were already removed from the SSSB site at the time of this report being drafted, and ORISE performed a confirmatory survey of these survey units before they were removed from the SSSB site. APTIM submitted its Surface Ship Support Barge Final Status Survey Plan, Revision 2 (FSS), dated January 23, 2023 (ML23037A809). This revision clarified in Chapter 2.0 that release surveys of the CS (tent where segmentation occurred) will be based on the Multi-Agency Radiation Survey and Assessment of Materials and Equipment (MARSAME) (ML090260577) using a MARSSIM type survey. Also, the revision clarified in Chapter 3.0, that the CS and associated ventilation system will be surveyed as a structure. The NRC RAIs on February 3, 2023 (ML23037A854 Pkg).
APTIM responses to the RAIs were submitted on February 9, 2023 (ML22361A102) and March 18, 2023 (ML23193A441). The NRC determined that these responses, as well as the clarification of the approach for the CS, were acceptable and had no further questions.
Originally, the SSSB DWP stated that the CS would be left in place. APTIM was not able to leave the CS onsite event though it met unrestricted release criteria because the Shipyard would not allow such an action. Through discussion with NRC, the NRC informed APTIM that it could either use MARSAME or MARSSIM type survey for the CS removal (ML23254A254).
APTIM chose to use the MARSSIM type survey (ML23254A193).
The NRC staff considered it unrealistic to sum the potential dose from a structure and component as the structure and component have been removed from the SSSB site. The NRC staff verified that the CS and ventilation housing met the unrestricted release criteria through its independent assessment and through the ORISE confirmatory survey. Again, because the structure and component are no longer present at the SSSB site, the NRC staff believes it is not appropriate to include the dose contribution in the all-pathway dose because they are not present on SSSB site and therefore could not contribute to the residual radioactivity remaining on site. Also, groundwater was not potable under the site and was not a consideration for containing residual radioactivity, as such it was excluded from this assessment. The potential dose estimates are based solely on the average of systematic measurements (i.e., excluding the biased measurements) taken of the media present in each survey unit with the criteria being conservatively based either on residential farming or small apartment living equating to 25 mrem/y. As such, the hypothetical dose estimates are considered conservative for an industrial use area that is primarily open pavement. Also, the soil in survey units 20A and 20B was conservatively evaluated as though they were surface soil when, in reality, additional fill will be brought in to bring that area up to grade and further reduce any potential exposure. Lastly, the NRC staff note that, in paved survey units, the gross beta measurements were used to demonstrate compliance. These gross beta measurements do not have background subtraction leading to what staff would consider significantly overstated residual radioactivity concentrations in the paved survey units.
Confirmatory Survey A confirmatory survey was performed by the NRCs contractor (Oak Ridge Institute of Science and Education, ORISE) during the week of April 25 and May 15, 2023 (ML23269A057). At that time, almost all of the waste and operational support equipment had been removed, the soil within the CS footprint had been removed to a depth of approximately 6 or more below grade, and the inner liner of the CS had been removed. APTIM had completed its FSSs and believed it had met its commitments for release of the site.
Generally, ORISE was able to verify most of the surveys and information that APTIM had produced were consistent with meeting the release criteria and confidence was achieved relative to the measurement methods being utilized. However, ORISE did identify ~17 areas of high contamination or hot spots in soil under the CS (survey units 20A and 20B) during its scanning survey of that area. These hot spots were relatively small in area (i.e., less than 0.1 m2). APTIM was given the opportunity to remediate these areas, if practical, while ORISE was present on site and could verify the remediation. APTIM did remediate four of the hot spots at that time which was verified by ORISE rescanning the affected areas. ORISE then took samples of the three most elevated remaining hot spots for assessment. Upon analysis of the samples, it was determined that Co-60 was present in these samples that would preclude NRCs ability to confirm the affected survey units met the release criteria. APTIM subsequently performed additional remediation of the areas to remove the hot spots, and reperformed an FSS survey of the impacted survey units. The reported FSS data for these survey units included biased sampling verification that the hot spots had been adequately remediated.
The NRC staff believe the reason APTIM had missed the hot spots during its initial FSS surveys was due to their scanning technique being based on default guidance in MARSSIM which assumed an area of contamination of at least 0.25 m2, and for which the detector response would be subsequently longer than over a smaller area such as was found by ORISE. ORISEs scanning techniques were generally conducive to a more sensitive scanning survey, slower speed of progression and closer to the surface, than what APTIM had performed. If APTIM had recognized that smaller areas of significant contamination existed, it would have been expected to modify its scanning techniques appropriately to assure it achieved a proper sensitivity necessary to be compliant with regulations in 10 CFR 20.1501. APTIMs subsequent remediation of the discovered hot spots was consistent with its stated ALARA goal to achieve radiological conditions similar to the baseline surveys (pre-SSSB conditions).
Given the limited amount of impacted soil identified at the site and the fact that APTIM reperformed FSSs of the suspect survey units after remediation of the identified hot spots, the NRC staff have reasonable assurance that the submitted FSS reports from APTIM are reflective of site conditions and no significant elevations in soil remain.
Conclusions The NRC staff reviewed the FSS submittals provided by APTIM regarding the SSSB site on the Alabama Shipyard. NRC staff find that the SSSB FSSs adequately demonstrated consistency with the unrestricted release criteria in 10 CFR 20.1402.
6, Summary of Final Status Surveys for 29 Survey Units Phase and Accession No.
Survey Unit Classification Matrix Area (m2)
Area Scanned*
Survey Hypothetical Dose (mrem/y)
Any Elevations?
Elevation Dose (mrem/y)
Phase 1, ML23186A045 1
2 paved 781
~30%
1.0 N
N/A Phase 1, ML23186A045 2
2 paved 788
~45%
2.0 N
N/A Phase 1, ML23186A045 3
2 paved 793
~63%
1.5 N
N/A Phase 2, ML23207A230 4
2 paved 801
~34%
1.5 N
N/A Phase 2, ML23207A230 5
2 paved 833
~30%
1.5 N
N/A Phase 2, ML23207A230 6A 2
paved 318
~38%
1.75 N
N/A Phase 1, ML23186A045 7
2 paved 988
~46%
1.25 N
N/A Phase 1, ML23186A045 8
2 paved 988
~39%
1.5 N
N/A Phase 1, ML23186A045 9
2 paved 988
~35%
1.75 N
N/A Phase 2, ML23207A230 10 2
paved 817
~33%
2.25 N
N/A Phase 2, ML23207A230 11 2
paved 776
~36%
2.25 N
N/A Phase 2, ML23207A230 12A 2
paved 881
~26%
1.5 N
N/A Phase 2, ML23207A230 13A 2
paved 864
~26%
2.0 N
N/A Phase 2, ML23207A230 14A 2
paved 899
~25%
1.5 N
N/A Phase 1, ML23186A045 15 3
paved 2113
~33%
1.0 N
N/A Phase 2, ML23207A230 16 3
paved 2050
~14%
2.0 N
N/A Phase 2, ML23207A230 17 2
paved 4358
~25%
3.25 N
N/A Phase 1, ML23186A045 18A 2
soil 1165
~81%
0.04 N
N/A Phase 2, ML23207A230 18B 2
soil 500
~89%
0.35 N
N/A Phase 2, ML23207A230 19 2
soil 381
~80%
0.11 N
N/A Phase 2, ML23207A230 20A 1
soil 921
~100%
1.36 N
N/A Phase 2, ML23207A230 20B 1
soil 893
~100%
1.23 N
N/A Phase 1, ML23186A045 21 3
soil 2299
~83%
0 N
N/A Phase 2, ML23207A230 22 (storm drains) 2 Concrete/
n/a
~25%
3.0/0.10 N
N/A
7 Phase and Accession No.
Survey Unit Classification Matrix Area (m2)
Area Scanned*
Survey Hypothetical Dose (mrem/y)
Any Elevations?
Elevation Dose (mrem/y)
Sediment Phase 2, ML23207A230 23 1
paved 481
~100%
2.5 N
N/A Phase 2, ML23207A230 24 1
paved 791
~100%
1.25 N
N/A Phase 2, ML23207A230 CS 3
Fabric/metal frame
~10%
0 N
N/A Phase 2, ML23207A230 Ventilation unit 1
Metal housing
~100%
0 N
N/A
Area scanned is that area stated by APTIM for beta walkover surveys in paved areas or gamma walkover surveys for unpaved areas. Staff note that gamma walkover surveys were conducted over much of the site consistent with the FSS Plan.
ML23243B020; ML23243A863 OFFICE NMSS/DUWP/RDB NMSS/DUWP/RDB NMSS/DUWP/RTAB OGC/GCRPS/RMR
/NLO*
NAME ASnyder SAnderson CMcKenney AGendelman DATE Sep 6, 2023 Sep 13, 2023 Sep 13, 2023 Sep 26, 2023 OFFICE NMSS/DUWP NAME JMarshall DATE Sep 26, 2023