PNP 2025-005, 50-Year Containment Tendon Surveillance Inspection Summary Report
| ML25062A010 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/03/2025 |
| From: | Filbrandt A Holtec Palisades |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| PNP 2025-005, EPID L-2021-LLA-0099 | |
| Download: ML25062A010 (1) | |
Text
27780 Blue Star Highway, Covert, MI 49043 1 Holtec Palisades, LLC (Holtec Palisades) is the licensed owner of PNP. Holtec Decommissioning International, LLC (HDI) is the licensed operator of PNP while the facility is in decommissioning. Pursuant to the license transfer application submitted in connection with the PNP restart (Reference 3), licensed authority will transfer from HDI to Palisades Energy, LLC (Palisades Energy) upon NRCs approval of the transition from decommissioning back to power operations. Holtec Palisades will remain the licensed owner of PNP.
PNP 2025-005 10 CFR 50.55a March 3, 2025 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Palisades Nuclear Plant Renewed Facility Operating License No. DPR-20 NRC Docket No. 50-255
References:
- 1)
Holtec Decommissioning International, LLC letter to U.S. Nuclear Regulatory Commission (NRC), License Amendment Request to Revise Renewed Facility Operating License and Permanently Defueled Technical Specifications to Support Resumption of Power Operations, dated December 14, 2023 (ADAMS Accession No. ML23348A148)
- 2)
NRC letter to Entergy Operations, Inc., Palisades Nuclear Plant - Issuance of Amendment No. 272 RE: Permanently Defueled Technical Specifications (EPID L-2021-LLA-0099), dated May 13, 2022 (ADAMS Accession No. ML22039A198)
- 3)
Holtec Decommissioning International, LLC letter to U.S. Nuclear Regulatory Commission, Application for Order Consenting to Transfer of Control of License and Approving Conforming License Amendments, dated December 6, 2023 (ADAMS Accession No. ML23340A161)
Subject:
50-Year Containment Tendon Surveillance Inspection Summary Report Holtec1, on behalf of Holtec Palisades, LLC, is providing the Palisades Nuclear Plant (PNP) 50-Year Containment Tendon Surveillance Inspection Summary Report. The summary report is prepared in accordance with American Society of Mechanical Engineers (ASME)Section XI, Rules for Inservice Inspection of Nuclear Plant Components, 2013 Edition, No Addenda, and Title 10 of the Code of Federal Regulations (10 CFR) 50.55a, Codes and standards, paragraph (b)(2(viii),Section XI condition: Concrete containment examinations.
In Reference 1, Holtec submitted a license amendment request (LAR) to, in part, revise the PNP Renewed Facility Operating License (RFOL), Appendix A, Permanently Defueled Technical Specifications (PDTS) to reflect the reinstatement of the PNP power operations licensing basis (POLB) and resumption of power operations at PNP. The PNP repower regulatory framework includes revising the PDTS to restore the PNP power operations technical specifications (POTS) and reinstating the Administrative Controls Technical Specifications (TSs) that were deleted as part of the implementation of the PDTS (Reference 2).
PNP-2025-005 Page 2 of 2 Therefore, as described on pages 77 and 84 of the Reference 1 Enclosure, TS 5.5.5, Containment Structural Integrity Surveillance Program, and TS 5.6.7, Containment Structural Integrity Surveillance Report, respectively, are proposed for reinstatement to reflect the power operation condition of PNP. The Reference 1 LAR is currently in NRC review.
The subject PNP 50-Year Containment Tendon Surveillance Inspection Summary Report is being submitted in accordance with PNP Administrative Controls TS 5.6.7, as proposed in the Reference 1 LAR, which requires submittal of a report within 90 days after completion of the containment tendon surveillance tests. The surveillance inspection and testing activities were completed on December 30, 2024. Submittal of the summary report in compliance with proposed TS 5.6.7 is consistent with the regulatory framework for reinstatement of the PNP POLB and the resumption of power operations at PNP.
The PNP 50-Year Tendon Surveillance Summary Report is provided in the Enclosure with this letter.
Should you have any questions or require additional information, please contact Katherine Chenier, Manager, Design Engineering and Analysis at (269) 764-2733.
Respectfully, Amy Filbrandt Acting Regulatory Assurance Manager Holtec Palisades
Enclosure:
Palisades Nuclear Plant ASME Section XI, IWL, 50-Year Containment Tendon Surveillance Inspection Summary Report cc:
NRC Region III Regional Administrator NRC Senior Resident Inspector - Palisades Nuclear Plant NRC Project Manager - Palisades Nuclear Plant
PNP 2025-005 ENCLOSURE PALISADES NUCLEAR PLANT ASME SECTION XI, IWL 50-YEAR CONTAINMENT TENDON SURVEILLANCE INSPECTION
SUMMARY
REPORT
PNP 2025-005 Enclosure Page 1 of 19 2024 CONTAINMENT STRUCTURAL INTEGRITY SURVEILLANCE PROGRAM, INSERVICE INSPECTION
SUMMARY
Submitted in accordance with American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, "Rules for Inservice Inspection of Nuclear Plant Components," Article IWA-6000, "Records and Reports" 2013 Edition, No Addenda
- 1.
Date:
August 26, 2024 through December 30, 2024
- 2.
Company Headquarters:
Holtec Decommissioning International, LLC (HDI)
Krishna P. Singh Technology Campus1 Holtec Blvd.
Camden, NJ 08104
- 3.
Plant:
Palisades Nuclear Plant 27780 Blue Star Highway Covert, Michigan 49043
- 4.
Unit No:
One
- 5.
Commercial Service Date:
December 31, 1971
- 6.
Major Component Inspected:
Component Manufacturer Equipment Number Post-tensioning System Bechtel N-54A
- 7.
Completion Date of Examination:
December 30, 2024
- 8.
Authorized Inspection Agency:
Hartford Steam Boiler of Connecticut Hartford, Connecticut
PNP 2025-005 Enclosure Page 2 of 19 1 Holtec Palisades, LLC (Holtec Palisades) is the licensed owner of PNP. Holtec Decommissioning International, LLC (HDI) is the licensed operator of PNP while the facility is in decommissioning. Pursuant to the license transfer application submitted in connection with the PNP restart (Reference 1), licensed authority will transfer from HDI to Palisades Energy, LLC (Palisades Energy) upon NRCs approval of the transition from decommissioning back to power operations. Holtec Palisades will remain the licensed owner of PNP.
1.0 PURPOSE Holtec1, on behalf of Holtec Palisades, LLC, is providing the Palisades Nuclear Plant (PNP) 50-Year Containment Tendon Surveillance Inspection Summary Report. The summary report is prepared in accordance with American Society of Mechanical Engineers (ASME)Section XI, "Rules for Inservice Inspection of Nuclear Plant Components," 2013 Edition, No Addenda, and Title 10 of the Code of Federal Regulations (10 CFR) 50.55a, "Codes and standards, paragraph (b)(2(viii),Section XI condition: Concrete containment examinations."
The provided summary report supports the reinstatement of the PNP power operations licensing basis (POLB), which includes restoring Administrative Controls Technical Specification TS 5.5.5, "Containment Structural Integrity Surveillance Program," and TS 5.6.7, "Containment Structural Integrity Surveillance Report." These TSs were included in the power operations technical specifications (POTS) License Amendment Request (LAR) submitted to the NRC on December 14, 2023 (ADAMS Accession No. ML23348A148). The LAR is currently in NRC review.
The summary report is being submitted in accordance with PNP Administrative Controls TS 5.6.7, as proposed in the POTS LAR, which requires submittal of a report within 90 days after completion of the containment tendon surveillance tests. The surveillance inspection and testing activities were completed on December 30, 2024. Submittal of the summary report in compliance with proposed TS 5.6.7 is consistent with the regulatory framework for reinstatement of the PNP POLB and the resumption of power operations at PNP.
2.0 EXAMINATION AND INSPECTION SCOPE The examination and inspection scope for the 50-year tendon surveillance is summarized in Table 2.1. In addition to the required 13 ASME Section XI scope tendons, Palisades also replaced all accessible grease can gaskets (171 total) on the top (dome) end of the vertical tendons. Furthermore, 20 grease cap gaskets on the vertical tendons were replaced on the bottom end in the tendon gallery (tendon tunnel).
This significantly increased the number of tendon anchorages that were visually observed and/or inspected from 26 anchorages (2 at each of the 13 tendons) to 217 anchorages.
During this supplemental gasket replacement, four tendons were noted (V-30, V-104, V-130, and V-324) as having either missing and/or protruding buttonheads. This prompted additional inspections to assess their condition. As a result, the number of ASME IWL-2522 lift off tests performed also increased from the original scope of 13 tendons to 17.
These four tendons are considered as added scope and are listed in Table 2.1 with an asterisk (*) next to the tendon number.
Appendix A summarizes the remainder of the findings associated with the tendons where the grease caps were replaced.
PNP 2025-005 Enclosure Page 3 of 18 2.1 EXAMINATION CATEGORY L-B, UNBONDED POST-TENSIONING SYSTEM (ASME Section XI Table 2500-1)
Cat. L-B Item L2.10 Tendon Examination Category Item Number Parts Examined Examination Examination Requirement Acceptance Standard Comments/results L-B L2.10 Dome Tendons D2-03 (Common)
D1-10 D2-16 D3-21 Tendon IWL-2522 IWL-3221.1 Satisfactory L-B L2.10 Vertical Tendons V-334 (Common)
V-88 V-100 V-284 V-30*
V-104*
V-130*
V-324*
Tendon IWL-2522 IWL-3221.1 Satisfactory L-B L2.10 Horizontal Tendons H-42DF (Common)
H-67AE H-45BD H-72DF H-87BF Tendon IWL-2522 IWL-3221.1 Satisfactory
- Indicates this tendon was not part of the original scope.
2.1 EXAMINATION CATEGORY L-B, UNBONDED POST-TENSIONING SYSTEM (Continued)
Cat. L-B Item L2.20 Wire or Strand Examination Category Item Number Parts Examined Examination Examination Requirement Acceptance Standard Comments/results L-B L2.20 Tendons D3-21 H-72DF V-284 Wire or Strand IWL-2523 IWL-3221.2 Satisfactory
PNP 2025-005 Enclosure Page 4 of 18 2.1 EXAMINATION CATEGORY L-B, UNBONDED POST-TENSIONING SYSTEM (Continued)
Cat. L-B Item L2.30 Anchorage Hardware and Surrounding Concrete Examination Category Item Number Parts Examined Examination Examination Requirement Acceptance Standard Comments L-B L2.30 D2-03 Anchorage Hardware and Surrounding Concrete IWL-2524 Detailed Visual (VT-1)
IWL-3221.3 Satisfactory D1-10 Satisfactory D2-16 Satisfactory D3-21 Satisfactory L-B L2.30 V-334 Anchorage Hardware and Surrounding Concrete IWL-2524 Detailed Visual (VT-1)
IWL-3221.3 Satisfactory V-88 Satisfactory V-100 Satisfactory V-284 Two buttonheads were missing on the Field (bottom) end of V-284. IR PAL-03318. Refer to Section 3.1 for conclusion.
V-30*
One protruding wire on the Shop (top) end of V-30. IR PAL-04840. Refer to Section 3.1 for conclusion.
V-104*
Two protruding wires on the Shop (top) end of V-104. IR PAL-04880. Refer to Section 3.1 for conclusion.
V-130*
One protruding wire on the Shop (top) end of V-130. IR PAL-04878. Refer to Section 3.1 for conclusion.
V-324*
Three wires protruding and two wires missing were missing on the Shop (top) end of V-324. IR PAL-03168. Refer to Section 3.1 for conclusion.
L-B L2.30 H-42DF Anchorage Hardware and Surrounding Concrete IWL-2524 Detailed Visual (VT-1)
IWL-3221.3 Satisfactory H-67AE Satisfactory H-45BD One buttonhead was missing on the Field ("B" Buttress) end of H-45BD. IR PAL-03397. Refer to Section 3.1 for conclusion.
H-72DF Two buttonheads were broken on the Field ("D" Buttress) end after re-tensioning H-72DF. The buttonheads were found after removing the hydraulic ram from the tendon. See Section 3.1 for conclusion.
H-87BF Satisfactory
- Indicates this tendon was not part of the original scope.
PNP 2025-005 Enclosure Page 5 of 18 2.1 EXAMINATION CATEGORY L-B, UNBONDED POST-TENSIONING SYSTEM (Continued)
Cat. L-B Item L2.40 Corrosion Protection Medium Examination Category Item Number Parts Examined Examination Examination Requirement Acceptance Standard Comments L-B L2.40 D2-03 Corrosion Protection Medium IWL-2525, IWL-2526 IWL-3221.4 20.8% Duct Volume Grease Replaced.
Tendon hardware was observed as remaining coated with grease. IR PAL-03277. Refer to Section 3.2 for conclusion.
D1-10 Satisfactory - 9.32% Duct Volume Grease Replaced D2-16 Satisfactory - 7.95% Duct Volume Grease Replaced D3-21 Satisfactory - 6.40% Duct Volume Grease Replaced L-B L2.40 V-334 Corrosion Protection Medium IWL-2525, IWL-2526 IWL-3221.4 17.3% Duct Volume Grease Replaced.
IR PAL-03316. Refer to Section 3.2 for conclusion.
V-88 Satisfactory - 0.62% Duct Volume Grease Replaced V-100 12.6% Duct Volume Grease Replaced.
Tendon hardware was observed as remaining coated with grease. IR PAL-03314. Refer to Section 3.2 for conclusion.
V-284 Satisfactory - 7.76% Duct Volume Grease Replaced L-B L2.40 H-42DF Corrosion Protection Medium IWL-2525, IWL-2526 IWL-3221.4 Satisfactory - 6.41% Duct Volume Grease Replaced H-67AE Satisfactory - 7.95% Duct Volume Grease Replaced H-45BD 17.68% Duct Volume Grease Replaced. IR PAL-03397. Refer to Section 3.2 for conclusion.
H-72DF Satisfactory - 2.60% Duct Volume Grease Replaced H-87BF Satisfactory - 7.89% Duct Volume Grease Replaced
PNP 2025-005 Enclosure Page 6 of 18 2.1 EXAMINATION CATEGORY L-B, UNBONDED POST-TENSIONING SYSTEM (Continued)
Cat. L-B Item L2.50 Free Water Examination Category Item Number Parts Examined Examination Examination Requirement Acceptance Standard Comments L-B L2.50 D2-03 Free Water IWL-2525 N/A 6 Oz Water Shop End, 512 Oz Water Field End. IR PAL-03277. No corrosion observed on anchor head, shims, or buttonheads. Refer to Section 3.3 for conclusion.
D1-10 Satisfactory D2-16 Satisfactory D3-21 Satisfactory L-B L2.50 V-334 Free Water IWL-2525 N/A Satisfactory V-88 96 Oz Water Field (Bottom) End. IR PAL-03272. No corrosion observed on anchor head, shims, or buttonheads.
Refer to Section 3.3 for conclusion.
V-62*
256 Oz Water Field (Bottom) End. IR PAL-04835. No corrosion observed on anchor head, shims, or buttonheads.
Refer to Section 3.3 for conclusion.
V-100 Satisfactory V-104*
256 Oz Water Field (Bottom) End. IR PAL-04835. No corrosion observed on anchor head, shims, or buttonheads.
Refer to Section 3.3 for conclusion.
V-284 Satisfactory L-B L2.50 H-42DF Free Water IWL-2525 N/A Satisfactory H-67AE Satisfactory H-45BD Satisfactory H-72DF Satisfactory H-87BF Satisfactory
- Indicates this tendon was not part of the original scope.
PNP 2025-005 Enclosure Page 7 of 18 3.0 EXAMINATION AND INSPECTION RESULTS AND CORRECTIVE ACTIONS 3.1 The following items did not meet the acceptance criteria of ASME Section XI IWL-3221.3(c), which states, "The condition of tendon anchorage areas is acceptable ifbroken or unseated wires, broken strands, and detached buttonheads were documented and accepted during a preservice examination or during a previous Inservice examination."
Detached buttonheads and broken or unseated wires were discovered in the following tendons and documented in the issue reports listed in the table below. There are 90 wire strands in each tendon.
Tendon Wires IR Lift Off Test Comments V-284 2 Buttonheads missing on Field End (Bottom)
PAL-03318 Lift off Test per IWL-2522 successfully performed with 87 effective wires.
Attempts to find missing buttonheads in grease caps unsuccessful, indicating buttonheads have been missing since cap last removed during original construction. V-284 was de-tensioned, and a strand removed and successfully tested.
V-30*
1 Protruding wire on the Shop End (Top).
PAL-04840 Lift off Test per IWL-2522 successfully performed with 86 effective wires.
Three wires in V-30 were previously identified as being discontinuous and subsequently removed in 2002.
V-104*
Two Protruding wires on the Shop End (Top).
PAL-04880 Lift off Test per IWL-2522 successfully performed with 86 effective wires.
None.
V-130*
Two Protruding wires on the Shop End (Top).
PAL-04878 Lift off Test per IWL-2522 successfully performed with 86 effective wires.
Two missing buttonheads previously reported were observed.
V-324*
3 Protruding wires on Top End (Shop)
PAL-03168 Lift off Test per IWL-2522 successfully performed with 85 effective wires.
The 3 protruding wires were reported as being pushed down significantly after the Lift off test. Two wires were also reported as missing. These wires were removed during the 1971 and 1973 tendon inspections.
H-45BD 1 Buttonhead missing on Field End ("B" Buttress)
PAL-03397 Lift off Test per IWL-2522 successfully performed with 89 effective wires.
Attempts to find missing buttonhead in grease cap unsuccessful, indicating buttonheads have been missing since cap last removed in 1975.
H-72DF 2 Buttonheads broken on the Field End ("D" Buttress).
PAL-03583 Lift off Test per IWL-2522 successfully performed with 87 effective wires.
The 2 buttonheads were found after the stressing was completed inside the stressing adapter. Buttonheads appeared to have been deformed from initial stressing activities as noted by the double crowns and die flashing.
- Indicates this tendon was not part of the original scope.
PNP 2025-005 Enclosure Page 8 of 18 V-284 The two missing buttonheads on the Field End (bottom) of V-284, documented in IR PAL-03318, were determined to be of no consequence. The cause of the missing buttonheads appears to be fabrication flaws during the buttonheading process, as evidenced by the lack of buttonheads removed in the grease cap. That is, the buttonheads would have remained in the grease cap unless they fell off prior to the cap's installation. The last record of cap installation was original construction. There were no visible signs of deterioration at the ends of the wires.
This tendon met all requirements for tendon force measurement as required by IWI-3221.1, "Tendon Force and Elongation," indicating that the as-found condition was structurally adequate. V-284 was de-tensioned, and one wire strand removed. This strand was examined for corrosion and mechanical damage along its entire length. No concerns were found. The strand was sent out for strength testing per IWL-2523. The tendon was then fully re-tensioned, and a second lift-off test was successfully performed in accordance with IWL-2522. This demonstrates that the as-left condition is structurally adequate.
V-30 This tendon was not part of the original inspection scope, this issue was discovered during the replacement of the accessible grease can gaskets on the Containment Dome. The protruding wire on the Shop End (Top) of V-30, documented in IR PAL-04840, was determined to be of no consequence. Protruding wires may be an indication of tendon wire corrosion or breakage resulting in increased wire length. However, protruding wires may also be an indication of wires shifting within the tendon duct or cable strand and not necessarily a break or damage to the wire. Inspection personnel have reported that protruding wires often maintain continuity between both ends and a lift off test may resolve the issue. An IWL-2522 Lift off Test was added to the scope and performed on 10-30-2024. This tendon met all requirements for tendon force measurement as required by IWI-3221.1, "Tendon Force and Elongation." This demonstrates that the condition is structurally adequate.
V-104 This tendon was not part of the original inspection scope, this issue was discovered during the replacement of the accessible grease can gaskets on the Containment Dome. The two protruding wires on the Shop End (Top) of V-104, documented in IR PAL-04880 were determined to be of no consequence. Protruding wires may be an indication of tendon wire corrosion or breakage resulting in increased wire length. However, protruding wires may also be an indication of wires shifting within the tendon duct or cable strand and not necessarily a break or damage to the wire. Inspection personnel have reported that protruding wires often maintain continuity between both ends and a lift off test may resolve the issue. An IWL-2522 Lift off Test was added to the scope and performed on 10-24-2024. This tendon met all requirements for tendon force measurement as required by IWI-3221.1, "Tendon Force and Elongation." This demonstrates that the condition is structurally adequate.
V-130 This tendon was not part of the original inspection scope, this issue was discovered during the replacement of the accessible grease can gaskets on the Containment Dome. The two protruding wires on the Shop End (Top) of V-130, documented in IR PAL-04878 were determined to be of no consequence. Protruding wires may be an indication of tendon wire corrosion or breakage resulting in increased wire length. However, protruding wires may also
PNP 2025-005 Enclosure Page 9 of 18 be an indication of wires shifting within the tendon duct or cable strand and not necessarily a break or damage to the wire. Inspection personnel have reported that protruding wires often maintain continuity between both ends and a lift off test may resolve the issue. An IWL-2522 Lift off Test was added to the scope and performed on 10-24-2024. This tendon met all requirements for tendon force measurement as required by IWI-3221.1, "Tendon Force and Elongation." This demonstrates that the condition is structurally adequate.
V-324 This tendon was not part of the original inspection scope, this issue was discovered during the replacement of the accessible grease can gaskets on the Containment Dome. The three protruding wires on the Shop End (Top) of V-324, documented in IR PAL-03168, were determined to be of no consequence. Protruding wires may be an indication of tendon wire corrosion or breakage resulting in increased wire length. However, protruding wires may also be an indication of wires shifting within the tendon duct or cable strand and not necessarily a break or damage to the wire. Inspection personnel have reported that protruding wires often maintain continuity between both ends and a lift off test may resolve the issue. An IWL-2522 Lift off Test was added to the scope and performed on 9-26-2024. This tendon met all requirements for tendon force measurement as required by IWI-3221.1, "Tendon Force and Elongation." This demonstrates that the condition is structurally adequate. The test report indicated that the three protruding wires were pushed down significantly by the lift of test, indicating that continuity in the wires was maintained. Two wires were also reported missing in this tendon that were recorded as being removed in the 1971 and 1973 inspections.
H-45BD The missing tendon buttonhead on H-45BD, documented in IR PAL-03397, was determined to be of no consequence. The cause of the missing buttonhead appears to be fabrication flaws during the buttonheading process or from the de-tensioning/re-tensioning performed in 1975, as evidenced by the lack of a buttonhead removed in the grease. That is, the buttonhead would have remained in the grease cap unless it fell off prior to the cap's installation. The last records of this installation were at original construction in 1969 and during a de-tensioning/re-tensioning of H-45BD in November 1975. There was no visible sign of deterioration at the end of the wires.
Additionally, this tendon met all requirements for tendon force measurement as required by IWI-3221.1, "Tendon Force and Elongation." This demonstrates that the condition is structurally adequate.
H-72DF The two broken tendon buttonheads found after re-tensioning H-72DF, documented in IR PAL-03583, were determined to be of no consequence. The cause of the missing buttonheads appeared to be fabrication flaws during the buttonheading process since both buttonheads were malformed with double crowns from the field forming process. Excessive gripping die flashing that extended below the buttonheads was also noted. This die flashing can change the stress field around the buttonhead resulting in a failure when tested. A wire strand from H-72DF was removed and it showed no corrosion or mechanical damage. The as-found and as-left requirements for tendon force measurement per IWI-3221.1, "Tendon Force and Elongation" were met for Tendon H-72DF. This demonstrates that the condition is structurally adequate.
As required by 10 CFR 50.55a (b) (2)(viii)(E), Holtec has considered the possibility that this condition may exist in inaccessible areas. Based on the results of inspections and tests, it is
PNP 2025-005 Enclosure Page 10 of 18 concluded that the degree of buttonhead or wire failures in inaccessible areas and the results of failures are the same as accessible areas. It is concluded that, even with the same level of failure, inaccessible tendons would meet performance requirements in a similar manner to that documented for accessible areas.
As a result of this evaluation, no repair/replacement activities were required; consequently, no additional examinations were required.
3.2 Section XI IWL-3221.4 states, "Corrosion protection medium is acceptable when the reserve alkalinity, water content, and soluble ion concentrations of all samples are within the limits specified in Table IWL-2525-1." Two samples of grease were removed from each end of the 13 surveillance tendons. Laboratory analysis of the sheathing filler revealed:
3.2.1 Ion Concentration - All tendon grease samples' ion concentrations were within their respective acceptance limits.
3.2.2 Moisture Content - All tendon grease samples' moisture contents were within the acceptance limit.
3.2.3 Reserve Alkalinity (Base Number) - All tendon grease samples' base numbers were above the acceptance limit of 0 mg KOH/g of sample. (Acceptance limit shall be at least 50% of the as-installed value, unless the as-installed value is 5 or less in which case the base number shall be no less than zero).
3.2.4 No signs of degradation of the grease, by either color or consistency, were noted on any of the tendons tested.
The following items did not meet the acceptance criteria of ASME Section XI IWL-3221.4, which states, "The absolute difference between the amount removed and the amount replaced shall not exceed 10% of the tendon net duct volume." The table below summarizes the tendons where the amount of grease replaced exceeded 10% of the tendon net duct volume.
Tendon Percent (%)
Replacement Issue Report (IR)
Gasket Replaced Comments D2-03 20.8%
PAL-03277 Shop & Field Ends Reported as leaking around gasket.
Gaskets were replaced.
V-100 12.6%
PAL-03314 Top (Shop End) &
Bottom (Field End)
Reported as leaking around gasket.
Gaskets were replaced.
V-334 17.3%
PAL-03316 Top (Shop End) &
Bottom (Field End)
Gaskets were replaced. Inspection report indicated that grease did not flow down through duct from the previous fill in 2018. Based on reports, grease was pumped into the duct in 2024 but poured into duct in 2018.
H-45BD 17.68%
PAL-03397 "B" Buttress (Field End) & "D" Buttress (Shop End)
Gaskets were replaced.
The tendons were inspected to ensure that corrosion protection medium adequately coated the anchorage hardware with acceptable results. Grease forms a protective coating for tendons and associated components and this function was not compromised by the amount of leakage noted. No significant corrosion was found. The tendons were refilled with grease and had acceptable grease replacement versus grease loss ratios.
PNP 2025-005 Enclosure Page 11 of 18 End cap elastomeric component (gasket) replacement was performed during the 50-year tendon surveillance with work order number 50084269 on all tendons listed in the table above.
Previous evaluation of these types of leaks has been attributed to grease filling techniques and subsequent heating of the grease by the sun and containment internal heat. Degradation of elastomeric components may be caused by exposure to the sun in addition to normal aging. The leakage was not considered significant; hence, had no impact on the operability of the containment or the containment post tensioning system.
As required by 10 CFR 50.55a(b)(2)(viii)(E), Holtec has considered the possibility that this condition may exist in inaccessible areas. Based on the results of inspections, it is concluded that the level of leakage in inaccessible areas could be the same as accessible areas. However, even if this condition exists in inaccessible areas, it is expected that tendons will meet performance requirements in a similar manner to that documented for accessible areas. This is based on visual examinations, where no absence of grease on the tendons was noted. As stated above in this section, the grease forms a protective coating for tendons and associated components and this function has not been compromised.
As a result of the evaluation, no repair/replacement activities were required; consequently, no additional examinations are required.
3.3 The following items did not meet the acceptance criteria of ASME Section XI IWL-3221.3(e), which states, "There is no evidence of free water."
Free water was discovered in the following tendons and documented in the issue reports listed in the table below. The water sample lab pH test results are also listed below:
Tendon Water IR Sample pH Comments D2-03 6 Oz. Shop End (SE) 512 Oz. Field End (NE)
PAL-03277 Shop = 9.06 Field = 12.1 Grease cap gasket on shop end observed to be degraded and leaking by. Replacement of end cap gaskets was completed. Lift off Test per IWL-2522 performed.
V-88 96 Oz. Field End (Bottom)
PAL-03272 8.70 Grease cap gasket on shop end observed to be degraded and leaking by. Replacement of end cap gaskets was completed. Lift off Test per IWL-2522 performed.
V-62*
256 Oz. Field End (Bottom)
PAL-04829 8.28 Replacement of end cap gaskets was completed.
V-104*
256 Oz. Field End (Bottom)
PAL-04880 9.40 Replacement of end cap gaskets was completed. Lift off Test per IWL-2522 performed.
- Indicates this tendon was not part of the original scope.
The cause of water infiltration has been attributed to degraded grease can gaskets, condensation, migration through concrete cold joints, and/or tendon sheathing. The cold joint and tendon grease sheathing are generally not watertight and can allow water infiltration when sufficient void space exists. There is no applicability to other plants on site since there are no other plants on site currently.
The anchorage hardware, bearing plate, and nearby concrete were visually inspected at all of the locations listed above. No adverse issues were found. The corrosion medium was noted as remaining coating the metal hardware at all locations. Any grease loss
PNP 2025-005 Enclosure Page 12 of 18 from cap removal was replaced and new end cap gaskets were installed. The grease forms a protective coating for tendons and associated components and this function has not been compromised by the presence of water.
In addition, Tendons D2-03, V-88, and V104 were successfully tested for force and elongation per IWL-2522.
As required by 10 CFR 50.55a (b) (2)(viii)(E), Holtec has considered the possibility that this condition may exist in inaccessible areas. Based on the results of inspections and tests, it is concluded that the water in tendons D2-03 may be due to their location and the existence of cold joints near the tendon end anchorage. In addition, the grease cap gasket on D2-03 was observed as being degraded on the shop end indicating another potential source of water. In the case of Tendons V-62, V-88, and V-104, it was concluded that the water intrusion may be due to degradation in the end cap gaskets on the top end of the Containment Building.
Even if this condition exists in inaccessible areas, it is expected that tendons would meet performance requirements in a similar manner to that documented for accessible areas.
This is based on visual examinations, where no absence of grease on the tendons was noted. As stated above in this section, the grease forms a protective coating for tendons and associated components and this function has not been compromised by the presence of water.
As a result, no repair/replacement activities were warranted. Hence, no additional examinations are required. There are no acceptance criteria for pH of the water given in the IWL Section 2525.2 (b), the only requirement is that the sample is analyzed for pH.
4.0
SUMMARY
The TS 5.5.5, "Containment Structural Integrity Surveillance Program," demonstrates continued containment operability by providing assurance that the containment is capable of fulfilling designed operating and accident functions. Based on an evaluation of the 50-year tendon surveillance results, and after reviewing the acceptable disposition of non-conforming items, Holtec concludes that the containment structure has not experienced abnormal degradation related to the post-tensioning system and continues to be operable.
PNP 2025-005 Enclosure Page 13 of 19 Appendix A Summary of Gasket Replacements Tendon End Gasket Changed Grease Coating Hardware
% Grease Replacement Water Total Comments V-02 Top 100%
12.27 0
IR-PAL-04315 V-04 Top 100%
7.59 0
V-06 Top & Bottom 100%
7.60 0
V-08 Top 100%
14.9 0
IR-PAL-04315 V-10 Top & Bottom 100%
13.50 0
IR-PAL-04315 V-12 Top 100%
9.90 0
V-14 Top & Bottom 100%
16.46 0
IR-PAL-04315 V-16 Top 100%
6.70 0
V-18 Top 100%
3.10 0
V-20 Top & Bottom 100%
4.88 0
V-22 Top 100%
1.99 0
V-24 Top 100%
8.46 0
V-26 Top & Bottom 100%
1.20 0
V-28 Top 100%
3.00 0
V-30 Added Scope Tendon See Section 2.0.
V-32 Top 100%
5.09 0
V-34 Top 100%
5.70 0
V-36 Top 100%
4.93 0
V-38 Top 100%
3.97 0
V-40 Top 100%
2.70 0
V-42 Top 100%
1.80 0
V-44 Top 100%
8.55 0
V-46 Top 100%
5.45 0
V-48 Top 100%
4.43 0
V-50 Top 100%
1.80 0
V-52 Top 100%
1.06 0
V-54 Top 100%
0.53 0
V-56 Top 100%
2.56 0
V-58 Top 100%
1.58 0
V-60 Top 100%
1.88 0
V-62 Added Scope Tendon See Section 2.0.
V-64 Top 100%
0.85 0
V-66 Top 100%
2.49 0
V-68 Top 100%
1.65 3 oz.
IR-PAL-03569. One bolt on grease cap found loose as potential source of water.
V-70 Top 100%
4.08 0
PNP 2025-005 Enclosure Page 14 of 19 Tendon End Gasket Changed Grease Coating Hardware
% Grease Replacement Water Total Comments V-72 Top 100%
1.29 0
V-74 Top 100%
2.38 0
V-76 Top 100%
1.38 0
V-78 Top 100%
2.17 0
V-80 Top 100%
1.10 0
V-82 Top 100%
2.38 0
V-84 Top 100%
1.49 0
V-86 Top 100%
3.80 0
V-88 Scope Tendon See Section 2.0.
V-90 Top 100%
4.20 0
V-92 Top 100%
2.05 0
V-94 Top & Bottom 100%
8.10 0
V-96 Top 100%
3.50 0
V-98 Top 100%
2.26 0
V-100 Scope Tendon See Section 2.0.
V-102 Top 100%
2.70 0
V-104 Added Scope Tendon See Section 2.0.
V-106 Top 100%
3.18 0
One protruding wire previously reported. No corrosion.
V-108 Top 100%
15.40 0
IR-PAL-04315 V-110 Top 100%
3.98 0
V-112 Top 100%
11.69 0
IR-PAL-04315 V-114 Top 100%
7.70 0
V-116 Top 100%
0.63 3 oz.
Two missing wires previously reported. No corrosion.
IR-PAL-03551. Two bolts on grease cap found loose as potential source of water.
V-118 Top 100%
2.40 0
V-120 Top 100%
4.60 0
V-122 Top 100%
6.50 0
V-124 Top 100%
4.83 0
V-126 Top 100%
2.01 0
V-128 Top 100%
1.74 0
V-130 Added Scope Tendon See Section 2.0.
V-132 Top 100%
1.78 0
V-134 Top 100%
2.03 0
V-136 Top 100%
1.94 0
V-138 Top 100%
2.03 0
V-140 Top 100%
2.90 0
V-142 Tendon Not Installed by Design.
PNP 2025-005 Enclosure Page 15 of 19 Tendon End Gasket Changed Grease Coating Hardware
% Grease Replacement Water Total Comments V-144 Top 100%
0.85 0
V-146 Top 100%
3.03 0
V-148 Top 100%
1.99 0
V-150 Top 100%
2.49 0
V-152 Top 100%
3.49 0
V-154 Top & Bottom 100%
8.53 0
V-156 Top 100%
6.30 0
V-158 Top 100%
3.70 0
V-160 Top 100%
1.06 0
V-162 Top 100%
3.26 0
V-164 Top 100%
1.86 0
V-166 Top 100%
2.90 0
V-168 Top 100%
0.53 0
V-170 Top 100%
2.35 0
V-172 Top 100%
1.37 0
V-174 Top 100%
3.37 0
V-176 Top & Bottom 100%
4.70
< 2 oz.
One missing wire previously reported. No additional breaks or corrosion. IR-PAL-04835 V-178 Top 100%
2.45 0
V-180 Top 100%
2.85 0
V-182 Top 100%
7.47 0
V-184 Top 100%
1.87 0
V-186 Top 100%
1.80 0
V-188 Top 100%
2.37 0
V-190 Top 100%
3.97 0
V-192 Top 100%
5.37 0
V-194 Top 100%
7.40 0
V-196 Top 100%
7.20 0
V-198 Top 100%
4.10 0
V-200 Top 100%
6.20 0
V-202 Top 100%
9.50 0
V-204 Top 100%
7.20 0
V-206 Top 100%
5.56 0
V-208 Tendon Not Installed by Design.
V-210 Top 100%
9.26 0
V-212 Top 100%
7.10 0
V-214 Top 100%
8.20 0
V-216 Top 100%
16.36 0
IR-PAL-04315
PNP 2025-005 Enclosure Page 16 of 19 Tendon End Gasket Changed Grease Coating Hardware
% Grease Replacement Water Total Comments V-218 Top 100%
3.80 0
V-220 Top 100%
5.79 0
V-222 Top 100%
11.1 0
IR-PAL-04315 V-224 Top 100%
8.10 0
V-226 Top 100%
7.70 0
V-228 Top 100%
4.20 0
V-230 Top & Bottom 100%
11.38 0
IR-PAL-04315 V-232 Top 100%
7.20 0
V-234 Top 100%
21.18 0
IR-PAL-04315 V-236 Top 100%
21.99 0
IR-PAL-04315 V-238 Top & Bottom 100%
2.68 0
V-240 Top 100%
7.30 0
V-242 Top 100%
5.90 0
V-244 Top 100%
15.87 0
IR-PAL-04315 V-246 Top 100%
8.90 0
V-248 Top & Bottom 100%
5.49 0
V-250 Top & Bottom 100%
8.17 0
V-252 Top 100%
21.50 0
IR-PAL-04315 V-254 Top 100%
5.80 0
V-256 Top 100%
5.40 0
V-258 Top 100%
21.3 0
IR-PAL-04315 V-260 Top & Bottom 100%
19.05 0
IR-PAL-04315 V-262 Top 100%
4.49 0
V-264 Top 100%
3.58 0
V-266 Top 100%
5.36 0
V-268 Top 100%
15.0 0
IR-PAL-04315 V-270 Top 100%
4.65 0
V-272 Top 100%
16.14 0
IR-PAL-04315 V-274 Top 100%
7.60 0
V-276 Top & Bottom 100%
6.69 0
V-278 Top 100%
5.90 0
V-280 Top 100%
5.65 0
V-282 Top 100%
16.0 0
IR-PAL-04315 V-284 Scope Tendon See Section 2.0.
V-286 Top 100%
9.55 0
V-288 Top 100%
5.87 0
V-290 Top 100%
9.00 0
V-292 Top 100%
15.87 0
IR-PAL-04315
PNP 2025-005 Enclosure Page 17 of 19 Tendon End Gasket Changed Grease Coating Hardware
% Grease Replacement Water Total Comments V-294 Top 100%
7.97 0
V-296 Top 100%
9.55 0
V-298 Top & Bottom 100%
7.20 0
V-300 Top 100%
9.30 0
V-302 Top 100%
7.56 0
V-304 Top 100%
9.25 0
V-306 Top & Bottom 100%
5.58 0
V-308 Top 100%
18.77 0
IR-PAL-04315 V-310 Top 100%
8.79 0
V-312 Top 100%
15.47 0
IR-PAL-04315 V-314 Top 100%
9.00 0
V-316 Inaccessible Tendon.
V-318 Inaccessible Tendon.
V-320 Inaccessible Tendon.
V-322 Top 100%
8.50 0
V-324 Added Scope Tendon See Section 2.0.
V-326 Top 100%
4.50 0
V-328 Inaccessible Tendon.
V-330 Inaccessible Tendon.
V-332 Top 100%
9.25 0
V-334 Scope Tendon See Section 2.0.
V-336 Top & Bottom 100%
15.10 0
IR-PAL-04315 V-338 Top & Bottom 100%
9.50 0
V-340 Top 100%
6.98 0
V-342 Top 100%
5.80 0
V-344 Top 100%
19.00 0
IR-PAL-04315 V-346 Top 100%
5.17 0
V-348 Top & Bottom 100%
9.07 0
V-350 Top 100%
14.37 0
IR-PAL-04315 V-352 Top 100%
31.00 0
IR-PAL-04315 V-354 Top 100%
6.79 0
V-356 Top 100%
20.8 0
IR-PAL-04315 V-358 Top 100%
13.78 0
IR-PAL-04315 V-360 Top 100%
7.90 0
As shown in the table above, tendons V-2,V-8,V-10,V-14,V-108,V-112,V-216,V-222,V-230,V-234,V-236,V-244,V-252,V-258,V-260,V-268,V-272,V-282,V-292,V-308,V-312,V-336,V-344,V-350,V-352,V-356 and V-358 did not meet the acceptance criteria of ASME Section XI IWL-3221.4, which states, "The absolute difference between the amount removed and the amount
PNP 2025-005 Enclosure Page 18 of 19 replaced shall not exceed 10% of the tendon net duct volume."
The tendons were inspected to ensure that corrosion protection medium remained coating the anchorage hardware with acceptable results. Grease forms a protective coating for tendons and associated components and this function was not compromised by the amount of leakage noted. No significant corrosion was found. The tendons were refilled with grease and had acceptable grease replacement versus grease loss ratios.
As required by 10 CFR 50.55a(b)(2)(viii)(E), Holtec has considered the possibility that this condition may exist in inaccessible areas. Based on the results of inspections, it is concluded that the level of leakage in inaccessible areas could be the same as accessible areas.
However, even if this condition exists in inaccessible areas, it is expected that tendons will meet performance requirements in a similar manner to that documented for accessible areas. This is based on visual examinations, where no absence of grease on the tendons was noted. As stated above in this section, the grease forms a protective coating for tendons and associated components and this function has not been compromised.
As shown in the table above, free water was discovered in tendons V-68, V-116, and V-176.
The amount of water was not sufficient to obtain samples for any of the three tendons. The cause of water infiltration has been attributed to degraded grease can gaskets and/or hardware, condensation, migration through concrete cold joints, and/or tendon sheathing. In the case of tendons V-68 and V-116 at least one nut on the grease can was observed as being loose which could have been a source of water.
The cold joint and tendon grease sheathing are generally not watertight and can allow water infiltration when sufficient void space exists. There is no applicability to other plants on site since there are no other plants currently.
The anchorage hardware, bearing plate, and nearby concrete were visually inspected. No adverse issues were found. The corrosion medium was noted as remaining coating the metal hardware. Any grease loss from cap removal was replaced and new end cap gaskets were installed. The grease forms a protective coating for tendons and associated components and this function has not been compromised by the presence of water.
As required by 10 CFR 50.55a (b) (2)(viii)(E), Holtec has considered the possibility that this condition may exist in inaccessible areas. Even if this condition exists in inaccessible areas, it is expected that, tendons would meet performance requirements in a similar manner to that documented for accessible areas. This is based on visual examinations, where no absence of grease on the tendons was noted. As stated above in this section, the grease forms a protective coating for tendons and associated components and this function has not been compromised by the presence of water.
As a result, no repair/replacement activities were warranted. Hence, no additional examinations are required.
PNP 2025-005 Enclosure Page 19 of 19
5.0 REFERENCES
- 1. Holtec Decommissioning International, LLC letter to U.S. Nuclear Regulatory Commission, Application for Order Consenting to Transfer of Control of License and Approving Conforming License Amendments, dated December 6, 2023 (ADAMS Accession No. ML23340A161)
- 2. Holtec Decommissioning International, LLC letter to U.S. Nuclear Regulatory Commission (NRC), License Amendment Request to Revise Renewed Facility Operating License and Permanently Defueled Technical Specifications to Support Resumption of Power Operations, dated December 14, 2023 (ADAMS Accession No. ML23348A148)