ML25133A223
| ML25133A223 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  (DPR-080, DPR-082) |
| Issue date: | 05/13/2025 |
| From: | Zawalick M Pacific Gas & Electric Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| DCl-25-050 | |
| Download: ML25133A223 (1) | |
Text
Maureen R. Zawalick Vice President Business and Technical Services Diablo Canyon Power Plant P.O. Box 56 Avila Beach, CA 93424 805.545.4242 Maureen.Zawalick@pge.com A member of the STARS Alliance Callaway x Diablo Canyon x Palo Verde x Wolf Creek PG&E Letter DCL-25-050 ATTN: Document Control Desk 10 CFR 54 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Diablo Canyon Units 1 and 2 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Supplement 4: Diablo Canyon Power Plant License Renewal Application, Amendment 6
References:
- 1. PG&E Letter DCL-23-118, License Renewal Application, dated November 7, 2023 (ML23311A154)
- 2. PG&E Letter DCL-24-092, Supplement and Annual Update: Diablo Canyon Power Plant License Renewal Application, Amendment 1, dated October 14, 2024 (ML24289A118)
- 3. PG&E Letter DCL-25-001, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation Diablo Canyon Safety Review Pacific Gas and Electric Company Diablo Canyon Units 1 and 2 (Set 2),
dated January 2, 2025 (ML25002A050)
- 4. PG&E Letter DCL-25-022, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation Diablo Canyon LRA Safety Review Pacific Gas and Electric Company Diablo Canyon Units 1 and 2 (Set 3), dated February 25, 2025 (ML25056A500)
- 5. PG&E Letter DCL-25-023, Supplement and Annual Update: Diablo Canyon Power Plant License Renewal Application, Amendment 4, dated March 6, 2025 (ML25069A508)
- 6. PG&E Letter DCL-25-046, Supplement 3: Diablo Canyon Power Plant License Renewal Application, Amendment 5, dated April 24, 2025 (ML25114A242)
Dear Commissioners and Staff:
In Reference 1, Pacific Gas and Electric Company (PG&E) submitted an operating license renewal application (LRA) for Diablo Canyon Power Plant (DCPP) Units 1 and 2 to extend the current Facility Operating Licenses an additional 20 years beyond their current expiration dates. In References 2, 3, 4, 5, and 6, PG&E amended the LRA. To support NRC's review of the LRA, PG&E is providing a voluntary supplement to the LRA included in the Enclosure.
The Enclosure includes a description of the changes along with the affected section(s) and page number(s) of the docketed full LRA (Reference 1) where the Pacific Gas anti Elecmr: Company*
Document Control Desk PG&E Letter DCL-25-050 Page 2 A member of the STARS Alliance Callaway x Diablo Canyon x Palo Verde x Wolf Creek changes apply. For clarity, revisions to the LRA are provided with deleted text by red strikethroughs and inserted text by blue underline. Bolded LRA text indicates portions that were previously amended by References 2, 3, 4, 5, or 6.
PG&E makes no new or revised regulatory commitments (as defined by NEI 99-04) in this submittal.
If you have any questions or require additional information, please contact Mr. Philippe Soenen at (805) 459-3701.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on ____________________.
Sincerely, Maureen R. Zawalick Vice President, Business and Technical Services Enclosure cc:
cc/enc:
Diablo Distribution Anthony Chu, Chief, California Department of Public Health Kim Conway, NRC Environmental Project Manager
$OLVVD1HXKDXVHQ, NRC$FWLQJ License Renewal Branch Chief Brian Harris, NRC Senior Project Manager Mahdi O. Hayes, NRC Senior Resident Inspector Delphine Hou, California Department of Water Resources Samson S. Lee, NRR Senior Project Manager John D. Monninger, NRC Region IV Deputy Administrator May 13, 2025
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Enclosure PG&E Letter DCL-25-050 Diablo Canyon Power Plant, Units 1 and 2 License Renewal Application, Amendment 6, Change Description and Revisions
Enclosure PG&E Letter DCL-25-050 Page 1 of 2 Supplement - DCPP LRA, Amendment 6 Affected License Renewal Application (LRA) Sections: Table 3.6.2-1 LRA Page Numbers: 3.6-18 Description of Change:
LRA Table 3.6.2-1 is updated to clarify the population of components for Component Type "Insulated Cable and Connections." The existing "Insulated Cable and Connections" line that reflects those components exposed to oil residue (see Plant Specific Note 3) is revised to correct the NUREG-1801 Item and Table 1 Item to "None" since General Note I is cited. A new line for "Insulated Cable and Connections" is further added to reflect the population of components that are not exposed to oil residue, and therefore, NUREG-1801 Item VI.A.LP-33 and Table 1 Item 3.6-1, 008 are applicable.
Enclosure PG&E Letter DCL-25-050 Page 2 of 2 Supplement - DCPP LRA, Amendment 6 LRA Table 3.6.2-1 on page 3.6-18 (as modified by DCL-24-092, Enclosure 1, Attachment C) is revised as follows:
Table 3.6.2-1: Electrical and Instrument and Controls - Summary of Aging Management Evaluation - Electrical Components Component Type Intended Function Material Environment Aging Effect Requiring Management Aging Management Program NUREG-1801 Item Table 1 Item Notes Insulated Cable and Connections (including terminal blocks, fuse holders, etc.)
Electrical Continuity, Insulate (Electrical)
Various Organic Polymers Adverse Localized Environment Reduced Insulation Resistance; Moisture Intrusion and Radiation-Induced Oxidation Insulation Material for Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements (B.2.3.36)
VI.A.LP-33None 3.6-1, 008None I, 3 Insulated Cable and Connections (including terminal blocks, fuse holders, etc.)
Electrical Continuity, Insulate (Electrical)
Various Organic Polymers Adverse Localized Environment Reduced Insulation Resistance; Moisture Intrusion and Radiation-Induced Oxidation Insulation Material for Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements (B.2.3.36)
VI.A.LP-33 3.6-1, 008 A
General Notes A. Consistent with component, material, environment, aging effect, and AMP listed for NUREG-1801 line item. AMP is consistent with NUREG-1801 AMP description.
I Aging effect in NUREG-1801 for this component, material, and environment combination is not applicable.
Plant Specific Notes
- 3. An adverse localized environment (oil mist) was identified for in scope cables and connections (located in the auxiliary building, elev. 115). The DCPP Insulation Material for Electrical Cables and Connections Not Subject to 10 CFR 50.49 Environmental Qualification Requirements AMP (B.2.3.36) will manage the aging effects by periodic inspections and cable surface cleaning until a solution to prevent or divert oil from the affected cables is implemented. See Section B.2.3.36.
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Enclosure PG&E Letter DCL-25-050 Page 1 of 2 Supplement - DCPP LRA, Amendment 6 Affected License Renewal Application (LRA) Sections: Section B.2.3.28 LRA Page Numbers: B.2-135 and B.2-136 Description of Change:
LRA Section B.2.3.28 is revised to update the DCPP ASME Section XI, Subsection IWE aging management program (AMP) operating experience discussion on containment liner moisture barriers. The revision deletes the statement regarding Unit 1 having no such moisture barriers to eliminate potential future confusion. If any areas are identified in the future as a moisture barrier, in either Unit, they will be managed by the DCPP ASME Section XI, Subsection IWE AMP.
Enclosure PG&E Letter DCL-25-050 Page 2 of 2 Supplement - DCPP LRA, Amendment 6 LRA Section B.2.3.28 on pages B.2-135 and B.2-136 (as modified by DCL-24-092,, Attachment EEE) is revised as follows:
B.2.3.28 ASME Section XI, Subsection IWE Operating Experience Industry Operating Experience x
RIS 2016-07, "Containment Shell or Liner Moisture Barrier Inspection," reiterated the NRC position regarding inservice inspection requirements for moisture barrier materials.
The results of the initial evaluation concluded that this document was not applicable to DCPP. However, a subsequent review determined that the DCPP Units 1 and 2 include containment liner caulking in Unit 2 meets the definition of a moisture barriers as defined in RIS 2016-07. This is in the scope of LR and is managed by the DCPP ASME Section XI, Subsection IWE AMP. PG&E revised the IWE inspection procedure to inspect the containment liner moisture barrier for degradation.
Plant Specific Operating Experience Unit 2 inspection of containment liner moisture barriers in the Spring 2024 refueling outage identified areas of the liner moisture barrier that did not meet acceptance criteria. These findings were entered into the CAP and are currently scheduled to be resolved in the next Unit 2 refueling outage in 2025. Unit 1 has no containment liner moisture barrier. A review of DCPP OE on containment liner moisture barriers identified no degradation of the containment liner due to potential intrusion of moisture into inaccessible areas at the interface of the containment liner with the concrete containment floor.