Text

License Amendment Request 24-07, Revision to Required Action Completion Times Consistent with NUREG-1431, Revision 5
	ML24366A127
Person / Time
Site:	Diablo Canyon
Issue date:	12/31/2024
From:	Mcbride D; Pacific Gas & Electric Co
To:	; Office of Nuclear Reactor Regulation, Document Control Desk
References
	DCL-24-121
	Download: ML24366A127 (1)
	v • d • e

Pacific Gas and Electric Company 0

Daniel J. McBride Director Nuclear Operations SeNices Diablo Canyon Power Plan!

Mail code 104/51506 P.O. Box 56 Avila Beach, CA 93424 805.545.4113 Dan.Mc Bride@pge.com PG&E Letter DCL-24-121 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Diablo Canyon Units 1 and 2 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 License Amendment Request 24-07 Revision to Required Action Completion Times Consistent with NUREG-1431,

Revision 5

Dear Commissioners and Staff:

Pursuant to 10 CFR 50.90, Pacific Gas and Electric Company (PG&E) hereby requests approval of the enclosed proposed amendment to Diablo Canyon Power Plant (DCPP), Unit 1 and 2 Technical Specifications (TS) 3.4.10, "Pressurizer Safety Valves", 3.4.12, "Low Temperature Overpressure Protection (L TOP) System", 3.7.4, "10% Atmospheric Dump Valves (ADVs)", and 3.7.6, "Condensate Storage Tank (CST)."

The proposed license amendment request (LAR) revises completion times associated with these TS to be consistent with the NUREG-1431, Revision 5, Completion Times.

Approval of the proposed amendment is requested by December 31, 2025. Once approved, the amendment will be implemented within 120 days.

PG&E makes no regulatory commitments (as defined by NEI 99-04) in this letter.

This letter includes no revisions to existing regulatory commitments.

The enclosure to this letter contains the evaluation of the proposed change.

In accordance with site administrative procedures and the Quality Assurance Program, the proposed amendment has been reviewed by the Plant Staff Review Committee.

A member of the STARS (Strategic Tea ming and Resource Sharing)

All1ance Callaway

Diablo Canyon

Palo Verde

Wolf Creek

Document Control Desk Page 2 PG&E Letter DCL-24-121 Pursuant to 10 CFR 50.91, PG&E is notifying the State of California of this LAR by transmitting a copy of this letter and enclosure to the California Department of Public Health.

If you have any questions or require additional information, please contact James Morris, Manager, Nuclear Regulatory Services, at 805-545-4609.

I state under penalty of perjury that the foregoing is true and correct.

Sincerely, Daniel J. McBride Director, Nuclear Operations Services kjse/51261669 Enclosure cc:

Diablo Distribution cc/enc:

Anthony Chu, Branch Chief, California Dept of Public Health Mahdi 0. Hayes, NRC Senior Resident Inspector Samson S. Lee, NRR Project Manager John D. Monninger, NRC Region IV Administrator A

member of the STARS (Strategic Teaming and Rernurce Sharing)

Alliance Callaway

Diablo Canyon,

Pa(o Verde

Wolf Creek

Enclosure PG&E Letter DCL-24-121 Page 1 of 9 Evaluation of the Proposed Change

Subject:

License Amendment Request 24-07, Revision to Required Action Completion Times for Technical Specifications 3.4.10, 3.4.12, 3.7.4, and 3.7.6 1.

SUMMARY

DESCRIPTION 2.

DETAILED DESCRIPTION 2.1 System Design and Operation 2.2 Current Technical Specifications Requirements 2.3 Reason for the Proposed Change 3.

TECHNICAL EVALUATION 4.

REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 No Significant Hazards Consideration 4.4 Conclusions 5.

ENVIRONMENTAL CONSIDERATION 6.

REFERENCES ATTACHMENTS:

1. Proposed Technical Specification Changes (Mark-Up)

2. Revised Technical Specification Page

3. Proposed Technical Specification Bases Changes (Mark-Up) - For Information Only

Enclosure PG&E Letter DCL-24-121 EVALUATION 1.

SUMMARY

DESCRIPTION The proposed changes in this license amendment request (LAR) would modify the Technical Specification (TS) requirements related to the Required Actions (RAs)

Completion Times (CTs) for Diablo Canyon Power Plant (DCPP) TS 3.4.10, Pressurizer Safety Valves, 3.4.12, Low Temperature Overpressure Protection (LTOP)

System, 3.7.4, 10% Atmospheric Dump Valves (ADVs), and 3.7.6, Condensate Storage Tank (CST) to the following:

Change the TS 3.4.10 Required Action B.2 CT from 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

Change the TS 3.4.12 Required Action G.1 CT from 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

Change the TS 3.7.4 Required Action D.2 CT from 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

Change the TS 3.7.6 Required Action B.2 CT from 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

The proposed changes to the TS 3.4.10, 3.4.12, 3.7.4, and 3.7.6 CTs are consistent with the corresponding NUREG-1431, Revision 5 (Reference 1) CTs.

2.

DETAILED DESCRIPTION 2.1 System Design and Operation The proposed amendment changes the specified CTs below.

TS 3.4.10, Pressurizer Safety Valves CT for Required Action B.2 The pressurizer safety valves provide, in conjunction with the Reactor Protection System, overpressure protection for the reactor coolant system (RCS). If the Required Action of A.1 cannot be met within the required CT or if two or more pressurizer safety valves are inoperable, the plant must be brought to a MODE in which the requirement does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months (Required Action B.1) and to MODE 4 with any RCS cold leg temperatures Low Temperature Overpressure Protection (LTOP) arming temperature specified in the Pressure and Temperature Limits Report (PTLR) within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action B.2).

Page 2 of 9

Enclosure PG&E Letter DCL-24-121 TS 3.4.12, Low Temperature Overpressure Protection (LTOP) System CT for Required Action G.1 The LTOP System controls RCS pressure at low temperatures so the integrity of the reactor coolant pressure boundary (RCPB) is not compromised by violating the pressure and temperature (P/T) limits of 10 CFR 50, Appendix G (Reference 2). The RCS must be depressurized, and a vent must be established within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (Required Action G.1 ) when:

a. Both required RCS Class I PORVs are inoperable; or

b. A Required Action and associated CT of Condition A, B, D, E, or F is not met; or

c. The LTOP System is inoperable for any reason other than Condition A, B, C, D, E, or F.

TS 3.7.4, 10% Atmospheric Dump Valves (ADVs) CT for Required Action D.2 The 10% ADVs provide a method for cooling the unit to residual heat removal (RHR) entry conditions should the preferred heat sink via the 40% steam dump valves to the condenser not be available. If the ADV lines cannot be restored to OPERABLE status within the associated CT, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months (Required Action D.1), and in MODE 4, without reliance upon steam generator for heat removal, within 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months (Required Action D.2).

TS 3.7.6, Condensate Storage Tank (CST) CT for Required Action B.2 The CST provides a safety grade source of water to the steam generators for removing decay and sensible heat from the RCS. If the CST cannot be restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months (Required Action B.1), and in MODE 4, without reliance on the steam generator for heat removal, within 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months (Required Action B.2).

2.2 Current Technical Specifications Requirements The current Required Action CTs for the four TS Required Actions discussed above are in accordance with NUREG-1431, Revision 1 (Reference 3) which were the basis for the DCPP Standard Technical Specifications (STS) conversion to the Westinghouse improved STS.

Page 3 of 9

Enclosure PG&E Letter DCL-24-121 2.3 Reason for the Proposed Change The proposed amendment would make the specified DCPP TS Required Action CTs consistent with NUREG-1431, Revision 5.

3.

TECHNICAL EVALUATION The proposed amendment changes the following TS Required Action CTs consistent with NUREG-1431, Revision 5:

The TS 3.4.10 Required Action B.2 CT to place the plant in Mode 4 with any RCS cold leg temperatures less than or equal to LTOP arming temperature specified in the PTLR, is changed from 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The Required Action B.2 is not changed. The proposed CT change is reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

The TS 3.4.12 Required Action G.1 CT to depressurize the RCS and establish an RCS vent, is changed from 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The Required Action G.1 is not changed.

Required Action G.1 requires that the RCS must be depressurized, and a vent must be established within the Completion Time when:

a. Both required RCS are inoperable, or

b. Required Action and associated Completion Times of Condition A, B, D, E, or F is not met, or

c. The LTOP system is inoperable for any reason other than Condition A, B, C, D, E, or F.

The proposed CT change considers the time required to place the plant in this Condition and the relatively low probability of an overpressure event during this time period due to increased operator awareness of administrative control requirements.

The TS 3.7.4 Required Action D.2 CT, to place the plant in Mode 4, without reliance upon the steam generator for heat removal, is changed from 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The Required Action D.2 is not changed. The proposed CT change is reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

The TS 3.7.6 Required Action B.2 CT to place the plant in Mode 4, without reliance on the steam generator for heat removal, is changed from 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . The Required Action B.2 is not changed. The proposed CT change is reasonable, based on Page 4 of 9

Enclosure PG&E Letter DCL-24-121 operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

The purpose of the TS Required Actions is to ensure the affected systems are restored to operable status consistent with the requirements of the LCO to support the assumptions of the applicable safety analyses, or that the plant is placed in an operating Mode where the systems are no longer required operable. The proposed CT changes allows additional time to restore the affected systems to operable status or to plan and execute the required plant system configuration changes to place the plant in an operating Mode where the systems are no longer required operable. The additional time allowed minimizes the potential for human errors while restoring plant equipment to operable status or changing plant modes. The proposed CT changes are acceptable because the revised CTs continue to provide adequate assurance of safe plant operation.

4.

REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 10 CFR 50.36 In Section 50.36 of Title 10 of the Code of Federal Regulations (10 CFR 50.36), the Nuclear Regulatory Commission established its regulatory requirements related to the content of the TSs. Pursuant to 10 CFR 50.36, TSs are required to include items in the following categories: (1) safety limits, limiting safety system setting, and limiting control settings; (2) limiting conditions for operation (LCOs); (3) surveillance requirements; (4) design features; and (5) administrative controls. The rule does not specify specific requirements for items (1) through (5) in a plants TSs.

As stated in 10 CFR 50.36(c)(2)(i), LCOs are the lowest functional capability or performance level of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow remedial action permitted by technical specifications until the condition can be met. The remedial actions in the TSs are specified in terms of LCO conditions, required actions, and CTs, or allowed outage times, to complete the required actions. When an LCO is not being met, the CTs specified in the TSs are the time allowed in the TSs for completing the specified required actions. The conditions and Page 5 of 9

Enclosure PG&E Letter DCL-24-121 required actions specified in the TSs must be a reasonable time for completing the required actions while maintaining the safe operation of the plant.

NUREG-1431, Revision 5 In NUREG-1431, Revision 5, the improved STS are listed for Westinghouse plants. The proposed Completion Time changes for TS 3.4.10, TS 3.4.12, TS 3.7.4, and TS 3.7.6 discussed in this LAR are consistent with those found in NUREG-1431, Revision 5 for each respective TS. As stated in NUREG-1431, Revision 5, The improved STS were developed based on the criteria in the Final Commission Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, dated July 22, 1993 (58 FR 39132), which was subsequently codified by changes to Section 36 of Part 50 of Title 10 of the Code of Federal Regulations (10 CFR 50.36) (60 FR 36953). Licensees are encouraged to upgrade their technical specifications consistent with those criteria and conforming, to the practical extent, to Revision 5 to the improved STS.

General Design Criteria The DCPP units are designed to comply with the Atomic Energy Commission (AEC)

(now NRC) General Design Criteria (GDC) for Nuclear Power Plant Construction Permits, published in July 1967. DCPP Updated Final Safety Analysis Report (UFSAR)

Sections 3.1.1 through 3.1.10 provide a listing of these criteria and a discussion of conformance. The DCPP design basis is the 1967 GDCs. Subsequent PG&E commitments to GDCs issued later (e.g., 1971 GDC) have been made that are described in the UFSAR discussion of the related 1967 GDCs, or in other UFSAR sections specific to the applicable systems and detailed analysis.

The applicable DCPP license basis GDC to this LAR are Criterion 6, 1967 - Reactor Core Design, and GDC Criterion 10, 1971 with respect to the design of the reactor core, as described in UFSAR Section 3.1.3.1.

Criterion 6, 1967 - Reactor Core Design states:

The reactor core shall be designed to function throughout its design lifetime, without exceeding acceptable fuel damage limits which have been stipulated and justified. The core design, together with reliable process and decay heat removal systems, shall provide for this capability under all expected conditions of normal operation with appropriate margins for uncertainties and for transient situations which can be anticipated, including the effects of the loss of power to recirculation pumps, tripping out Page 6 of 9

Enclosure PG&E Letter DCL-24-121 of a turbine generator set, isolation of the reactor from its primary heat sink, and loss of all offsite power.

Criterion 6, 1967 is applicable to the process and decay heat removal systems including the RCS. As described in UFSAR Section 3.1.3.1, GDC Criterion 10, 1971 supersedes GDC Criterion 6, 1967 for DCPP with respect to the design of the reactor core.

The Criterion 10, 1971 - Reactor Design is:

The reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that specified acceptable fuel design limits are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences.

As described in UFSAR Table 3.1-2, there is no direct association for the 1967 GDC with Criterion 15, 1971 - Reactor Coolant System Design or Criterion 34, 1971 -

Residual Heat Removal.

The changes contained in this LAR do not involve a change to the design of a plant component and therefore do not impact DCPP compliance with the applicable DCPP design basis GDC.

4.2 Precedent The proposed amendment includes information that is consistent with Callaway Plant License Amendment 188 that was approved by NRC, in November 2008 (Reference 4).

4.3 No Significant Hazards Consideration

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change increases specified Completion Times to be consistent with the improved Standard Technical Specifications (STS) for Westinghouse plants. The proposed change does not involve a significant increase in the probability of an accident previously evaluated because the change involves no change to the plant or its modes of operation. The proposed change does not increase the consequences of an accident because the design-basis mitigation function of the affected systems is not changed and the consequences of an accident during the increased Completion Time are no different from those during the existing Completion Time. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

Page 7 of 9

Enclosure PG&E Letter DCL-24-121

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed change does not change the design, configuration, or method of operation of the plant. The proposed change does not involve a physical alteration of the plant (no new or different kind of equipment will be installed). Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed change increases specified Completion Times to be consistent with the improved STS for Westinghouse plants. The proposed change continues to ensure that adequate margins of safety are maintained.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, PG&E concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c),

and, accordingly, a finding of no significant hazards consideration is justified.

4.4 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.

ENVIRONMENTAL CONSIDERATION A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant Page 8 of 9

Enclosure PG&E Letter DCL-24-121 Page 9 of 9 increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

6.

REFERENCES 1.

NUREG-1431, Revision 5, Standard Technical Specifications Westinghouse Plants, September 2021.

2.

10 CFR 50, Appendix G.

3.

NUREG-1431, Revision 1, Standard Technical Specifications Westinghouse Plants, April 1995.

4.

NRC Letter Callaway Plant, Unit 1 - Issuance of Amendment Re: Adoption of Industry Travelers TSTF-247-A and TSTF-352-A (TAC Nos. MD7515 and MD7516) dated November 25, 2008 [ADAMS Accession No. ML082910895]

Enclosure PG&E Letter DCL-24-121 Proposed Technical Specification Changes (Mark-Up)

24 Pressurizer Safety Valves 3.4.10 3.4 REACTOR COOLANT SYSTEM (R_CS) 3.4.10 Pressurizer Safety Valves LCO 3.4.1 0 Three pressurizer safety valves shall be OPERABLE with lift settings

~ 2460 psig and$ 2510 psig.

APPLICABILITY:

MODES 1, 2, and 3, MODE 4 with all RCS cold leg temperatures > Low Temperature Overpressure Protection (L TOP) arming temperature specified in the PTLR.

NOTE-----------

The lift settings are not required to be within the LCO limits during MODES 3 and 4 for the purpose of setting the pressurizer safety valves under ambient (hot) conditions. This exception is allowed for 54 hours6.25e-4 days 0.015 hours 8.928571e-5 weeks 2.0547e-5 months following entry into MODE 3 provided a preliminary cold setting was made prior to heatup.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One pressurizer safety A.1 Restore valve to 15 minutes valve inoperable.

OPERABLE status.

B.

Required Action and 8.1 Be in MODE 3.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion AND Time not met.

OR r° Two or more pressurizer 8.2 Be in MODE 4 with any 42 hours4.861111e-4 days 0.0117 hours 6.944444e-5 weeks 1.5981e-5 months safety valves inoperable.

RCS cold leg temperatures $ L TOP arming temperature specified in the PTLR.

SURVEILLANCE REQUIREMENTS SR 3.4.10.1 SURVEILLANCE Verify each pressurizer safety valve is OPERABLE in accordance with the lnservice Testing Program.

Following testing, lift settings shall be within+/- 1 %.

FREQUENCY In accordance with the lnservice Testing Progral'l)

DIABLO CANYON - UNITS 1 & 2 3.4-18 Unit 1 - Amendment No. 4a5 Unit 2 - Amendment No. 4e5

12 ACTIONS (continued)

CONDITION E.

One required RCS Class I PORV inoperable in MODE4.

F.

One required RCS Class I PORV inoperable in MODE 5 or 6, with the vessel head closure bolts not fully de-tensioned.

G. Two required RCS Class I PORVs inoperable.

OR Required Action and associated Completion Time of Condition A, B, D, E, or F not met.

OR L TOP System inoperable for any reason other than Condition A, B, C, D, E, or F.

DIABLO CANYON - UNITS 1 & 2 E.1 F.1 G.1 REQUIRED ACTION Restore required RCS Class I PORV to OPERABLE status.

Restore required RCS Class I PORV to OPERABLE status.

Depressurize RCS and establish RCS vent of

~ 2.07 square inches.

LTOP System 3.4.12 COMPLETION TIME 7 days 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months

~

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3. 7 PLANT SYSTEMS 3.7.6 Condensate Storage Tank (CST)

LCO 3. 7.6 The CST shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3, CST 3.7.6 MODE 4 when steam generator is relied upon for heat removal.

ACTIONS CONDITION REQUIRED ACTION A.

CST inoperable.

A.1 Verify by administrative means OPERABILITY of backup water supply.

AND A.2 Restore CST to OPERABLE status.

B. Required Action and B.1 Be in MODE 3.

associated Completion AND Time not met.

B.2 Be in MODE 4, without reliance on steam generator for heat removal.

SURVEILLANCE REQUIREMENTS SURVEILLANCE SR 3.7.6.1 Verify the CST water volume is~ 200,000 gallons for Unit 1 and:".. 166,000 gallons for Unit 2.

COMPLETION TIME 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months AND Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter 7 days 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months

~

+S hours FREQUENCY In accordance with the Surveillance Frequency Control Program

-j DIABLO CANYON - UNITS 1 & 2 3.7-13 Unit 1 - Amendment No. ~.200,-2-84 Unit 2 - Amendment No. ~.204-.~

Enclosure PG&E Letter DCL-24-121 Revised Technical Specification Page Remove Page Insert Page 3.4-18 3.4-18 3.4-25 3.4-25 3.7-8 3.7-8 3.7-13 3.7-13

Pressurizer Safety Valves 3.4.10 DIABLO CANYON - UNITS 1 & 2 Rev 17 Page 19 of 40 Tab_3!4u3r17.doc 1119.1135 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.10 Pressurizer Safety Valves LCO 3.4.10 Three pressurizer safety valves shall be OPERABLE with lift settings 2460 psig and 2510 psig.

APPLICABILITY:

MODES 1, 2, and 3, MODE 4 with all RCS cold leg temperatures > Low Temperature Overpressure Protection (LTOP) arming temperature specified in the PTLR.

NOTE-----------------------------------------

The lift settings are not required to be within the LCO limits during MODES 3 and 4 for the purpose of setting the pressurizer safety valves under ambient (hot) conditions. This exception is allowed for 54 hours6.25e-4 days 0.015 hours 8.928571e-5 weeks 2.0547e-5 months following entry into MODE 3 provided a preliminary cold setting was made prior to heatup.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One pressurizer safety valve inoperable.

A.1 Restore valve to OPERABLE status.

15 minutes B. Required Action and associated Completion Time not met.

OR B.1 Be in MODE 3.

AND 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Two or more pressurizer safety valves inoperable.

B.2 Be in MODE 4 with any RCS cold leg temperatures LTOP arming temperature specified in the PTLR.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.10.1 Verify each pressurizer safety valve is OPERABLE in accordance with the Inservice Testing Program.

Following testing, lift settings shall be within +/- 1%.

In accordance with the Inservice Testing Program 3.4-18 Unit 1 - Amendment No. 135, Unit 2 - Amendment No. 135,

LTOP System 3.4.12 DIABLO CANYON - UNITS 1 & 2 Rev 17 Page 26 of 40 Tab_3!4u3r17.doc 1119.1135 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. One required RCS Class I PORV inoperable in MODE 4.

E.1 Restore required RCS Class I PORV to OPERABLE status.

7 days F.

One required RCS Class I PORV inoperable in MODE 5 or 6, with the vessel head closure bolts not fully de-tensioned.

F.1 Restore required RCS Class I PORV to OPERABLE status.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months G. Two required RCS Class I PORVs inoperable.

OR G.1 Depressurize RCS and establish RCS vent of 2.07 square inches.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Required Action and associated Completion Time of Condition A, B, D, E, or F not met.

OR LTOP System inoperable for any reason other than Condition A, B, C, D, E, or F.

3.4-25 Unit 1 - Amendment No. 135,200, 229, Unit 2 - Amendment No. 135,201, 231,

ADVs 3.7.4 DIABLO CANYON - UNITS 1 & 2 Rev 21 Page 9 of 37 Tab_3!7u3r21.doc 1119.1157 3.7 PLANT SYSTEMS 3.7.4 10% Atmospheric Dump Valves (ADVs)

LCO 3.7.4 Four ADV lines shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3, MODE 4 when steam generator is relied upon for heat removal.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required ADV line inoperable.

A.1 Restore required ADV line to OPERABLE status 7 days OR In accordance with the RICT Program B. Two required ADV lines inoperable.

B.1 Restore at least one ADV line to OPERABLE status.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months C. Three or more required ADV lines inoperable.

C.1 Restore at least two ADV lines to OPERABLE status.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months D. Required Action and associated Completion Time not met.

D.1 Be in MODE 3.

AND 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months D.2 Be in MODE 4 without reliance upon steam generator for heat removal.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 3.7-8 Unit 1 - Amendment No. 135,169, 245, Unit 2 - Amendment No. 135,170, 247,

CST 3.7.6 DIABLO CANYON - UNITS 1 & 2 Rev 21 Page 15 of 37 Tab_3!7u3r21.doc 1119.1157 3.7 PLANT SYSTEMS 3.7.6 Condensate Storage Tank (CST)

LCO 3.7.6 The CST shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3, MODE 4 when steam generator is relied upon for heat removal.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. CST inoperable.

A.1 Verify by administrative means OPERABILITY of backup water supply.

AND 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months AND Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter A.2 Restore CST to OPERABLE status.

7 days B. Required Action and associated Completion Time not met.

B.1 Be in MODE 3.

AND 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months B.2 Be in MODE 4, without reliance on steam generator for heat removal.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.6.1 Verify the CST water volume is 200,000 gallons for Unit 1 and 166,000 gallons for Unit 2.

In accordance with the Surveillance Frequency Control Program 3.7-13 Unit 1 - Amendment No. 135,200,204, Unit 2 - Amendment No. 135,201,205,

Enclosure PG&E Letter DCL-24-121 Proposed Technical Specification Bases Changes (Mark-Up) - For Information Only

Pressurizer Safety Valves B 3.4.10 DIABLO CANYON - UNITS 1 & 2 Rev 14B Page 49 of 114 BASES (continued)

APPLICABILITY In MODES 1, 2, and 3, and portions of MODE 4 above the LTOP arming temperature, OPERABILITY of three valves is required because the combined capacity is required to keep reactor coolant pressure below 110% of its design value during certain accidents. MODE 3 and portions of MODE 4 are conservatively included, although the listed accidents may not require the safety valves for protection.

The LCO is not applicable in MODE 4 when any RCS cold leg temperature is LTOP arming temperature specified in the PTLR, or in MODE 5 because LTOP is provided. Overpressure protection is not required in MODE 6 with reactor vessel head closure bolts fully de-tensioned.

The Note allows entry into MODES 3 and 4 with the lift settings outside the LCO limits. This permits testing and examination of the safety valves at high pressure and temperature near their normal operating range, but only after the valves have had a preliminary cold setting.

The cold setting gives assurance that the valves are OPERABLE near their design condition. Only one valve at a time will be removed from service for testing. The 54 hour6.25e-4 days 0.015 hours 8.928571e-5 weeks 2.0547e-5 months exception is based on 18 hour2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months outage time for each of the three valves. The 18 hour2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months period is derived from operating experience that hot testing can be performed in this time frame.

ACTIONS A.1 With one pressurizer safety valve inoperable, restoration must take place within 15 minutes. The Completion Time of 15 minutes reflects the importance of maintaining the RCS Overpressure Protection System. An inoperable safety valve coincident with an RCS overpressure event could challenge the integrity of the pressure boundary.

B.1 and B.2 If the Required Action of A.1 cannot be met within the required Completion Time or if two or more pressurizer safety valves are inoperable, the plant must be brought to a MODE in which the requirement does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 4 with any RCS cold leg temperatures LTOP arming temperature specified in the PTLR within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. With any RCS cold leg temperature at or (continued) 24

LTOP System B 3.4.12 DIABLO CANYON - UNITS 1 & 2 Rev 14B Page 72 of 114 BASES ACTIONS (continued)

E.1 In MODE 4 when any RCS cold leg temperature is LTOP arming temperature specified in the PTLR, with one required RCS Class I PORV inoperable, the RCS Class I PORV must be restored to OPERABLE status within a Completion Time of 7 days. Two RCS Class I PORVs are required to provide low temperature overpressure mitigation while withstanding a single failure of an active component.

The Completion Time considers the facts that only one of the RCS Class I PORVs is required to mitigate an overpressure transient and that the likelihood of an active failure of the remaining valve path during this time period is very low.

F.1 The consequences of operational events that will overpressurize the RCS are more severe at lower temperature (Ref. 7). Thus, with one of the two RCS Class I PORVs inoperable in MODE 5 or in MODE 6 with the head on and the vessel head closure bolts not fully de-tensioned, the Completion Time to restore two valves to OPERABLE status is 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

The Completion Time represents a reasonable time to investigate and repair several types of relief valve failures without exposure to a lengthy period with only one OPERABLE RCS Class I PORV to protect against overpressure events.

G.1 The RCS must be depressurized and a vent must be established within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months when:

a.

Both required RCS Class I PORVs are inoperable; or b.

A Required Action and associated Completion Time of Condition A, B, D, E, or F is not met; or c.

The LTOP System is inoperable for any reason other than Condition A, B, C, D, E, or F.

The vent must be sized 2.07 square inches to ensure that the flow capacity is greater than that required for the worst case mass input transient reasonable during the applicable MODES. This action is needed to protect the RCPB from a low temperature overpressure event and a possible brittle failure of the reactor vessel.

The Completion Time considers the time required to place the plant in this Condition and the relatively low probability of an overpressure event during this time period due to increased operator awareness of administrative control requirements.

(continued) 12

ADVs B 3.7.4 DIABLO CANYON - UNITS 1 & 2 Rev 14C Page 22 of 102 BASES (continued)

APPLICABILITY In MODES 1, 2, and 3, all four ADVs are required to be OPERABLE. In MODE 4, only the ADVs associated with the steam generators being relied upon for heat removal, are required to be OPERABLE.

In MODE 5 or 6, an SGTR is not a credible event.

ACTIONS A.1 With one required ADV line inoperable, action must be taken to restore OPERABLE status within 7 days or in accordance with the Risk Informed Completion Time Program. The 7 day Completion Time allows for the redundant capability afforded by the remaining OPERABLE ADV lines, a non-safety grade backup in the Steam Bypass System, and MSSVs and is based on a PRA analysis and the low probability of a SGTR and LOOP event occurring during this period that would require the ADV lines.

B.1 With two ADV lines inoperable, action must be taken to restore at least one ADV line to OPERABLE status. This will result in at least three operable ADVs. Since the block valve can be closed to isolate an ADV, some repairs may be possible with the unit at power. The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time is reasonable to repair inoperable ADV lines, based on the availability of the Steam Dump System (40% steam dump valves to the condenser) and MSSVs, and the low probability of an event occurring during this period that would require the ADV lines.

C.1 With three or more ADV lines inoperable, action must be taken to restore at least two ADV lines to OPERABLE status. This will result in at least two operable ADVs. Since the block valve can be closed to isolate an ADV, some repairs may be possible with the unit at power.

The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time is reasonable to repair inoperable ADV lines, based on the availability of the Steam Dump System (40% steam dump valves to the condenser) and MSSVs, and the low probability of an event occurring during this period that would require the ADV lines.

D.1 and D.2 If the ADV lines cannot be restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and in MODE 4, without reliance upon steam generator for heat removal, within 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

(continued) 24

CST B 3.7.6 DIABLO CANYON - UNITS 1 & 2 Rev 14C Page 41 of 102 BASES ACTIONS (continued)

B.1 and B.2 If the CST cannot be restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and in MODE 4, without reliance on the steam generator for heat removal, within 18 hours2.083333e-4 days 0.005 hours 2.97619e-5 weeks 6.849e-6 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

SURVEILLANCE REQUIREMENTS SR 3.7.6.1 This SR verifies that the CST contains the required volume of cooling water. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

REFERENCES

1.

UFSAR, Sections 9.2.6 and 9.5.1.

2.

UFSAR, Chapter 6.

3.

UFSAR, Chapter 15.

4.

DCM S-3B.

24

v t e Letter Sequence Request
EPID:L-2024-LLA-0178, (Open)
Initiation Request Acceptance... Administration Questions 1 July 2025 Answers Results Approval... Other: NUREG-1431, Revision of Technical Specification Completion Time to Be Consistent with NUREG-1431, Revision 5
MONTHYEAR2025-02-07 [Table View]

DCL-24-121, License Amendment Request 24-07, Revision to Required Action Completion Times Consistent with NUREG-1431, Revision 5

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DCL-24-121, License Amendment Request 24-07, Revision to Required Action Completion Times Consistent with NUREG-1431, Revision 5

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Dear Commissioners and Staff:

Subject:

SUMMARY

SUMMARY

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