ML25223A096
| ML25223A096 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/08/2025 |
| From: | Blind A - No Known Affiliation |
| To: | Office of Nuclear Reactor Regulation |
| Dennis Galvin | |
| Shared Package | |
| ML25157A008 | List: |
| References | |
| OEDO-25-00290, EPID L-2025-CRS-0000 | |
| Download: ML25223A096 (0) | |
Text
August 8, 2025 Docket 05000255 of 1
12
Subject:
Second Supplemental Filing to May 15, 2025 10 CFR § 2.206 Petition - Steam Generator Tube Integrity at Palisades To: NRC Petition Review Board Cc: PalisadesRestartProject.Resource@nrc.gov From: Alan Blind Date: August 8, 2025
Dear NRC Petition Review Board,
I respectfully submit this second supplemental filing in support of my May 15, 2025 petition under 10 CFR § 2.206, titled:
Request for Enforcement Action Against Palisades Nuclear Plant for Violation of Technical Specification 3.4.17 Prior to Certified Shutdown, and for NRC to Require Compliance with This Condition Action Statement Before Restart.
This supplemental filing provides new, material information supporting my May 15, 2025 petition under 10 CFR § 2.206, specifically concerning steam generator (SG) tube integrity at the Palisades Nuclear Plant. It reflects my review of the NRCs July 30, 2025 Request for Additional Information (RAI) to Holtec (ML25211A324), Holtecs responses, and the NRCs March 20, 2025 Audit Plan (ML25070A153). While those documents
August 8, 2025 Docket 05000255 of 2
12 pertain to Holtecs pending license amendment for sleeving degraded tubes, they reveal important technical and regulatory deficiencies directly relevant to restart safety and license compliance.
This filing incorporates and applies enforceable provisions of the Palisades approved Technical Specifications (ML25157A127, Amendment No. 276),
including TS 3.4.13 (Steam Generator Tube Integrity), TS 5.5.8 (Steam Generator Program), and TS 5.6.8 (Steam Generator Tube Inspection Report). These specifications establish the plants approved licensing basis and require NRC review and approval before restart when tube integrity is in question.
The filing also documents Holtecs admission that the chemistry conditions inside the steam generators were not monitored, known, or controlled during the two-year shutdown (May 2022 to May 2024). In combination with Holtecs failure to produce the required Condition Monitoring and Operational Assessment (CMOA) from the prior operating cycle (Refueling Outage 27), this introduces substantial uncertainty into any forward-looking tube integrity analysis and must be considered in any forward looking operational assessment.
August 8, 2025 Docket 05000255 of 3
12 Additionally, this supplement highlights NRC Staffs own safety concerns raised in RAI Questions 13 and 22regarding early crack initiation, undetected circumferential cracking, and flawed modeling assumptions.
These concerns are compounded by the aging Alloy 600 tubes, the sudden substantial increase in the rate of SSC cracking, and the high number of newly identified flaws, including indications exceeding 90%
through-wall.
Finally, this filing clarifies that restart under these conditions is prohibited unless and until the NRC has reviewed and approved Holtecs updated Operational Assessment in accordance with TS 5.5.8. For clarity and traceability, Petitioners request that ADAMS Accession No. ML25157A127, NRC approval of Palisades License, be cited as the controlling license document in any NRC Staff response, Safety Evaluation Report, or Commission decision relating to this matter.
I. Holtecs Admission: Shutdown Chemistry Conditions Were Not Controlled In response to RAI Question 11, Holtec stated:
August 8, 2025 Docket 05000255 of 4
12 The primary side chemistry of the SG tubes during the two-year shutdown from May 2022 to May 2024 is not well known.
Holtec RAI Response, ML25211A324 This unmonitored period coincided with Palisades operating under its Defueled Safety Analysis Report (DSAR), where wet layup chemistry controls were not required by its decommissioning license, however, the plant's mill-annealed Alloy 600 tubes remained exposed to conditions conducive to primary water stress corrosion cracking (PWSCC), without documented protection.
This admission directly undermines the assumptions required for a valid Operational Assessment, as mandated by Palisades Technical Specification 5.5.8:
The SG Program shall establish inspection frequencies, repair limits, and performance criteria If any of the performance criteria are not met, the condition shall be reported and the plant shall not be returned to service until a NRC-approved Corrective Action Plan is completed.
Palisades Technical Specifications, ML25157A127, p. 662
August 8, 2025 Docket 05000255 of 5
12 Because Holtec cannot confirm the chemistry conditions to which the steam generator tubes were exposed during the two-year decommissioning period, any forward-looking degradation model is inherently non-conservative. As a result, restart must not be permitted without full NRC review, incorporation of these uncertainties and formal approval of the Operational Assessment and any proposed corrective actions, in accordance with TS 5.5.8.
II. NRCs Statements Raise Alarm Over Early Crack Initiation and Undetected Crack Growth NRC staff in RAI Question 22 wrote:
An alternate way of interpreting the Table 6-2 data is that some small percentage of the parent tubes with sleeves may experience relatively short times to crack initiation.
And in RAI Question 13:
It is possible that over time a parent tube could experience circumferential cracking at the outermost expansion that is not detected until propagating to a larger crack size.
August 8, 2025 Docket 05000255 of 6
12 Holtec did not rebut or clarify these concerns, which apply not only to sleeved tubes but to all SG tubes at Palisadesparticularly those with Alloy 600 exposed to unknown layup chemistry for two years. These statements reinforce the purpose of the forward-looking assessment requirements in TS 5.5.8 and NRC-endorsed guidance (NEI 97-06, Rev. 3):
In cases where performance criteria cannot be met or the operational assessment is inconclusive, the plant shall not be returned to service without NRC approval.
NEI 97-06, Rev. 3, § 3.3.1, p. 3-4 III. NRC Audit Request Confirms Petitioners Allegation and Exposes Missing Baseline Data In my original petition, I alleged that Entergy failed to submit the required Condition Monitoring and Operational Assessment report following Refueling Outage 27, in violation of TS 5.6.8:
The results of the steam generator tube inspections shall be included in the report including the results of the condition monitoring assessment, and if required, the results of the operational
August 8, 2025 Docket 05000255 of 7
12 assessment.
ML25157A127, p. 664 The NRCs March 20, 2025 Audit Plan (ML25070A153) confirms that Holtec was asked to produce Framatome Document 51-9321652-000a document that still does not appear in ADAMS and may never have been submitted by Entergy. Without this baseline data, Holtec lacks the evidence necessary to construct a credible forward-looking model of flaw growth and tube integrity.
IV. Technical Specifications Require NRC Approval Before Restart if Tube Integrity Is Not Assured This section replaces the original narrative to reflect the current enforceable license language.
A. Technical Specification 3.4.13 SG Tube Integrity All SG tubes shall be OPERABLE.
ML25157A127, p. 569 If any SG tube is not operable:
August 8, 2025 Docket 05000255 of 8
12 A.1 Be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> A.2 Be in Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> Ibid., p. 570 Restart is prohibited unless tube operability is confirmed.
B. Technical Specification 5.5.8 SG Program Requirements If any of the performance criteria are not met, the condition shall be reported and the plant shall not be returned to service until a NRC-approved Corrective Action Plan is completed.
Ibid., p. 662 This requirement, directly enforceable under the license, clearly prohibits re-entry into Mode 4 without NRC approval if tube integrity is in question.
C. Technical Specification 5.6.8 SG Tube Inspection Report The report shall be submitted within 90 days after initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 5.5.8.
Ibid., p. 664
August 8, 2025 Docket 05000255 of 9
12 This establishes a reporting deadline but does not override the prohibition on restart if performance criteria are unmet.
Because Holtec has admitted it lacks knowledge of primary-side chemistry, and the inspection data shows deep cracking, it cannot be presumed that tube integrity has been maintained. NRC review and approval of the Operational Assessment must occur before restart, consistent with the license and NEI 97-06.
V. The Role of Uncertainty in Operational Assessments As outlined in GSI-163 (NUREG-0933), NEI 97-06, and TS 5.5.8, predictive modeling of tube integrity must be based on known inspection results, chemistry conditions, degradation mechanisms, and material behavior.
Holtecs current assessment lacks critical inputs, including:
Verified chemistry conditions during shutdown; Baseline data from 1R27; Bounding assumptions for Alloy 600 degradation; NRC-reviewed predictions for crack growth under current conditions.
August 8, 2025 Docket 05000255 of 10 12 Given the extent of uncertainty, the only safe and compliant regulatory posture is to require NRC review of the full Operational Assessment prior to re-entry into Mode 4.
VI. Relief Requested The specific relief requested in the May 15, 2025 petition remains unchanged; however, it is now additionally supported, in this supplement, by the enforceable requirements of Technical Specifications 3.4.13, 5.5.8, and 5.6.8, as approved in Amendment No. 276 to the Palisades Operating License (ADAMS Accession No. ML25157A127). These provisions require that SG tube integrity be assured prior to restart and prohibit return to service unless a valid Operational Assessment demonstrates compliance with structural and leakage performance criteria. Critically, TS 5.5.8 explicitly requires that the plant shall not be returned to service until a Corrective Action Plan has been reviewed and approved by the NRC if performance criteria are not met.
Accordingly, this supplement adds the following new relief requests:
August 8, 2025 Docket 05000255 of 11 12 1.
The NRC must enforce the Palisades licensing basis by requiring Holtec to obtain explicit NRC review and approval of its Operational Assessment and restart justification before the plant enters Mode 4. This requirement is not discretionary; it is mandated by TS 5.5.8 and must be enforced to uphold the integrity of the license and ensure public safety.
2.
The NRC must explicitly consider the substantial uncertainty introduced by:
Holtecs admission that the primary side chemistry conditions were not known or monitored during the two-year shutdown from May 2022 to May 2024; and
The absence of a docketed Condition Monitoring and Operational Assessment for Refueling Outage 27 (Cycle 28),
which deprives the current Operational Assessment of a validated historical degradation baseline.
These unresolved gaps violate the spirit and intent of GSI-163 and contradict the predictive assurance required by both NEI 97-06 and Technical Specification 5.5.8. Restart under such uncertainty is not
August 8, 2025 Docket 05000255 of 12 12 consistent with the licensing basis and cannot proceed without full NRC evaluation and formal approval.