NLS2023018, Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling

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Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling
ML23124A358
Person / Time
Site: Cooper Entergy icon.png
Issue date: 05/03/2023
From: Dia K
Nebraska Public Power District (NPPD)
To:
Office of Nuclear Reactor Regulation, Document Control Desk
References
NLS2023018
Download: ML23124A358 (1)
v • d • e


Text

H Nebraska Public Power District

Alwllys there when you need us" 50.90 NLS2023018 May 3, 2023 Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001

Subject:

Application to Revise Technical Specifications to Adopt TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling" Cooper Nuclear Station, Docket No. 50-298, License No. DPR-46

Dear Sir or Madam:

Pursuant to 10 CFR 50.90, Nebraska Public Power District (NPPD) is submitting a request for an amendment to the Technical Specifications (TS) for Cooper Nuclear Station.

NPPD requests adoption ofTSTF-58 0, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling." The proposed change provides a Technical Specifications exception to entering Mode 4 if both required Residual Heat Removal shutdown cooling subsystems are inoperable. provides a description and assessment of the proposed changes. Attachment 2 provides the existing TS pages marked up to show the proposed changes. Attachment 3 provides revised (clean) TS pages. Attachment 4 provides existing TS Bases pages marked up to show the associated TS Bases changes and is provided for information only.

Approval of the proposed amendment is requested by May 3, 2024. Once approved, the amendmen t shall be implemented within 60 days.

There are no regulatory commitments made in this submittal.

The proposed TS changes have been reviewed by the necessary safety review committees (Station Operations Review Committee and Safety Review and Audit Board). In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," a copy of this application, with attachments, is being provided to the designated State of Nebraska Official.

If you should have any questions regarding this submittal, please contact Linda Dewhirst, Regulatory Affairs and Compliance Manager, at (402) 825-5416 .

. COOPER NUCLEAR STATION 72676 648A Ave/ P.O. Box 98 / Brownville, NE 68321 http://www.nppd.com

NLS2023018 Page 2 of2 I declare under penalty of perjury that the foregoing is true and correct.

Executed On:  ? / 3,/ ~o 2-3 Date Sincerely, Khalil Dia Site Vice President

/dv Attachments: 1. Description and Assessment

2. Proposed Technical Specifications Changes (Mark-up)
3. Revised Technical Specifications Pages
4. Proposed Technical Specifications Bases Changes (Mark-up) -

Information Only cc: Regional Administrator w/ attachments USNRC - Region IV Cooper Project Manager w/ attachments USNRC - NRR Plant Licensing Branch IV Senior Resident Inspector w/ attachments USNRC- CNS Nebraska Health and Human Services w/ attachments Department of Regulation and Li censure NPG Distribution w/ attachments CNS Records w/ attachments

NLS2023018 Page 1 of 4 Attachment 1 Description and Assessment Cooper Nuclear Station, Docket No. 50-298, License No. DPR-46 1.0 Description

2. 0 Assessment 2.1 Applicability of Safety Evaluation 2.2 Variation 3.0 Regulatory Analysis 3.1 No Significant Hazards Consideration Analysis 3.2 Conclusion 4.0 Environmental Evaluation

NLS2023018 Attachment 1 Page 2 of 4

1.0 DESCRIPTION

Nebraska Public Power District (NPPD) requests adoption ofTSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling." The proposed change provides a Technical Specifications (TS) exception to entering Mode 4 if both required Residual Heat Removal (RHR) shutdown cooling subsystems are inoperable.

2.0 ASSESSMENT 2.1 Applicability of Safety Evaluation Nebraska Public Power District (NPPD) has reviewed the safety evaluation for TSTF-580 provided to the Technical Specifications Task Force (TSTF) in a letter dated July 11, 2021. This review included a review of the Nuclear Regulatory Commission (NRC) staffs evaluation, as well as the information provided in TSTF-580. NPPD has concluded that the justifications presented in TSTF-580 and the safety evaluation prepared by the NRC staff are applicable to Cooper Nuclear Station (CNS) and justify this amendment for the incorporation of the changes to the CNS TS.

Adoption ofTSTF-566-A, "Revise Actions for Inoperable RHR Shutdown Cooling Subsystems,"

was approved by the NRC for CNS on December 2, 2020.

2.2 Variation NPPD is proposing the following variation from the TS changes described in TSTF-580 or the applicable parts of the NRC staffs safety evaluation. This variation does not affect the applicability ofTSTF-580 or the NRC staffs safety evaluation to the proposed license amendment.

The CNS TS utilize different numbering than the Standard Technical Specifications (STS) on which TSTF-580 was based. Specifically, CNS equivalent TS are numbered as TS 3.4.7 instead of the STS numbering of TS 3.4.8. This difference is administrative and does not affect the applicability of TSTF-580 to the CNS TS.

3.0 REGULATORY ANALYSIS

3 .1 No Significant Hazards Consideration Analysis Nebraska Public Power District (NPPD) requests adoption ofTSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling." The proposed change provides a Technical Specifications (TS) exception to entering MODE 4 if both required Residual Heat Removal (RHR) shutdown cooling subsystems are inoperable.

NLS2023018 Page 3 of 4 NPPD has evaluated if a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

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

Response: No The proposed change provides a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable. The RHR System in the shutdown cooling mode performs the important safety function of removing decay heat from the reactor coolant system during shutdown. The RHR System in the shutdown cooling mode is not an initiator of any accident previously evaluated or assumed to mitigate any accident previously evaluated. The design and function of the RHR System are not affected by the proposed change.

The proposed change would also exempt entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable and other operating modes of the RHR System are inoperable, such as Low Pressure Core Injection and RHR suppression pool cooling, and both subsystems of the support system for the RHR System heat exchangers, the RHR Service Water (RHRSW) System, are inoperable. The TS for those RHR operating modes and the RHRSW System require entering Mode 4 when both required subsystems are inoperable. Those operating modes and systems are not initiators to any accident previously evaluated but are used to mitigate the consequences of an accident previously evaluated.

However, the consequences of an accident previously evaluated resulting from remaining in Mode 3 versus Mode 4 when RHR shutdown cooling subsystems are inoperable are not significantly increased because there would be no dependable method to remove post-accident decay heat in Mode 4 if both required RHR shutdown cooling subsystems are inoperable.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

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

Response: No The proposed change provides a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable. The proposed change does not affect the design function or operation of the RHR System or the RHRSW System. No new equipment is being installed as a result of the proposed change. The proposed change affects the action taken when both required RHR shutdown cooling subsystems are inoperable, so no new failure mechanisms are created.

NLS2023018 Page 4 of 4 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 amendment involve a significant reduction in a margin of safety?

Response: No The proposed change provides a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable. The proposed change does not change any specific values or controlling parameters that define margin in the design or licensing basis.

No safety limits are affected by the proposed change. The proposed change applies when both required RHR shutdown cooling subsystems are inoperable, so no design or safety limits associated with the operation of the RHR System are affected.

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

Based on the above, NPPD 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.

3.2 Conclusion 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 Commission's 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.

4. ENVIRONMENTALEVALUATION 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, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant 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.

NLS2023018 Page 1 of 3 Attachment 2 Proposed Technical Specifications Changes (Mark-up)

Cooper Nuclear Station, Docket No. 50-298, License No. DPR-46 Revised Pages 3.4-15 3.4-16

RHR Shutdown Cooling System - Hot Shutdown 3.4.7 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4. 7 Residual Heat Removal (RHR) Shutdown Cooling System - Hot Shutdown LCO 3.4.7 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.

NOTES-------------------------------------------

1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of Surveillances.

APPLICABILITY: MODE 3, with reactor steam dome pressure less than the shutdown cooling permissive pressure.

ACTIONS

--------------------NO TE------------------------------------------------------------

Se para te Condition entry is allowed for each RHR shutdown cooling subsystem.

CONDITION REQUIRED ACTION COMPLETION TIME A. One ef--twerequired RHR A.1 Verify an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> shutdown cooling of decay heat removal is subsystems inoperable. available feF eael=l AND iA9J39Faele RJ==IR SRtJtee\&JA eeeliAg stJesystem. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter B. Required Action and B.1 Initiate action to restore Immediately associated Completion Time RHR shutdown cooling of Condition A not met. subsystem~ to OPERABLE status.

( continued)

Cooper 3.4-15 Amendment No.

RHR Shutdown Cooling System - Hot Shutdown 3.4.7 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. Two reguired RHR C.1 Verif~ an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> shutdown cooling of deca~ heat removal is subs~stems inoQerable. available for each AND inoQerable RHR shutdown cooling subs~stem. Once Qer 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter D. Reguired Action and ----------------------NOTE------------------

associated ComQletion Time LCO 3.0.3 and all other LCO of Condition C not met. Reguired Actions reguiring a MODE change to MODE 4 ma~ be sus1;2ended until one RHR shutdown cooling subs~stem is restored to OPERABLE status.

D.1 Initiate action to restore Immediate!~

one RHR shutdown cooling subs~stem to OPERABLE status.

G!;.No RHR shutdown cooling Gl~.1 Initiate action to restore Immediately subsystem in operation. one RHR shutdown cooling subsystem or one AND recirculation pump to operation.

No recirculation pump in operation. AND GE.2 Verify reactor coolant 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from circulation by an alternate discovery of no method. reactor coolant circulation AND Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND GE.3

- Monitor reactor coolant Once per hour temperature and pressure.

Cooper 3.4-16 Amendment No.

NLS2023018 Page 1 of 3 Attachment 3 Revised Technical Specifications Pages Cooper Nuclear Station, Docket No. 50-298, License No. DPR-46 Revised Pages 3.4-15 3.4-16

RHR Shutdown Cooling System - Hot Shutdown 3.4.7 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4. 7 Residual Heat Removal (RHR) Shutdown Cooling System - Hot Shutdown LCO 3.4.7 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.

NOTES-------------------------------------------

1. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
2. One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of Surveillances.

APPLICABILITY: MODE 3, with reactor steam dome pressure less than the shutdown cooling permissive pressure.

ACTIONS

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

Se para te Condition entry is allowed for each RHR shutdown cooling subsystem.

CONDITION REQUIRED ACTION COMPLETION TIME A. One required RHR A.1 Verify an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> shutdown cooling of decay heat removal is subsystem inoperable. available. AND Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter B. Required Action and B.1 Initiate action to restore Immediately associated Completion Time RHR shutdown cooling of Condition A not met. subsystem to OPERABLE status.

(continued)

Cooper 3.4-15 Amendment No.

RHR Shutdown Cooling System - Hot Shutdown 3.4.7 ACTIONS ( continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. Two required RHR C.1 Verify an alternate method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> shutdown cooling of decay heat removal is subsystems inoperable. available for each AND inoperable RHR shutdown cooling subsystem. Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter D. Required Action and ----------------------NOTE------------------

associated Completion Time LCO 3.0.3 and all other LCO of Condition C not met. Required Actions requiring a MODE change to MODE 4 may be suspended until one RHR shutdown cooling subsystem is restored to OPERABLE status.

D.1 Initiate action to restore Immediately one RHR shutdown cooling subsystem to OPERABLE status.

E. No RHR shutdown cooling E.1 Initiate action to restore Immediately subsystem in operation. one RHR shutdown cooling subsystem or one AND recirculation pump to operation.

No recirculation pump in operation. AND E.2 Verify reactor coolant 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from circulation by an alternate discovery of no method. reactor coolant circulation AND Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND E.3 Monitor reactor coolant Once per hour temperature and pressure.

Cooper 3.4-16 Amendment No.

NLS2023018 Page 1 of 4 Attachment 4 Proposed Technical Specifications Bases Changes (Mark-up) -

Information Only Cooper Nuclear Station, Docket No. 50-298, License No. DPR-46 Revised Pages B 3.4-36 B 3.4-37 B 3.4-38

RHR Shutdown Cooling System-Hot Shutdown B 3.4.7 BASES ACTIONS A Note has been provided to modify the ACTIONS related to RHR shutdown cooling subsystems. Section 1.3, Completion Times, specifies once a Condition has been entered, subsequent divisions, subsystems, components or variables expressed in the Condition, discovered to be inoperable or not within limits, will not result in separate entry into the Condition. Section 1.3 also specifies Required Actions of the Condition continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for inoperable shutdown cooling subsystems provide appropriate compensatory measures for separate inoperable shutdown cooling subsystems. As such, a Note has been provided that allows separate Condition entry for each inoperable RHR shutdown cooling subsystem.

With one required RHR shutdown cooling subsystem inoperable for decay heat removal, except as permitted by LCO Note 2, the overall reliability is reduced, because a single failure in the OPERABLE subsystem could result in reduced RHR shutdown cooling capability.

Therefore, an alternate method of decay heat removal must be provided.

With both RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdovm cooling subsystem inoperability.

This re establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore, verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will provide assurance of continued heat removal capability.

The required cooling capacity of the alternate method should be sufficient to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability. Alternate methods that can be used include (but are not limited to) the Condensate/Main Steam Systems, the Reactor Water Cleanup System, a combination of an ECCS pump and a safety/relief valve, or an inoperable but functional RHR shutdown cooling system.

Cooper B 3.4-36 01/06/21

RHR Shutdown Cooling System-Hot Shutdown B 3.4.7 BASES ACTIONS (continued)

If the required alternate methodfs-1 of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystemfs-1 to operable status. The Required Action will restore redundant decay heat removal paths. The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.

C. 1 With both required RHR shutdown cooling subsystems inoperable. an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability. This re-establishes backup decay heat removal capabilities.

similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore. verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will provide assurance of continued heat removal capability.

The required cooling capacity of the alternate method should be sufficient to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as. or contributing to. the alternate method capability. Alternate methods that can be used include (but are not limited to) the Reactor Water Cleanup System. or an inoperable but functional RHR shutdown cooling subsystem.

D.1 If the required alternate methods of decay heat removal cannot be verified within one hour. immediate action must be taken to restore at least one RHR shutdown cooling subsystem to OPERABLE status. The immediate Completion Time reflects the importance of restoring a method of heat removal.

Required Action D.1 is modified by a Note indicating that all required MODE changes to MODE 4 may be suspended until one RHR shutdown cooling subsystem is restored to OPERABLE status. In this case. LCO 3.0.3 and other Required Actions directing entry into MODE 4 could force the unit into a less safe condition in which there may be no adequate means to remove decay heat. It is more appropriate to allow the restoration of one of the RHR shutdown cooling subsystems before Cooper B 3.4-37 01/06/21

RHR Shutdown Cooling System-Hot Shutdown B 3.4.7 BASES ACTIONS ( continued) requiring entry into a condition in which that subsystem would be needed and exiting a condition where other sources of cooling are available.

When at least one RHR subsystem is restored to OPERABLE status. the Completion Times of LCO 3.0.3 or other Required Actions resume at the point at which they were suspended.

GE.1, GE.2, and GE.3 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as permitted by LCO Note 1, reactor coolant circulation by the RHR shutdown cooling subsystem or recirculation pump must be restored without delay.

Until RHR or recirculation pump operation is re-established, an alternate method of reactor coolant circulation must be placed into service. This will provide the necessary circulation for monitoring coolant temperature.

The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the coolant circulation function and is modified such that the 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> is applicable separately for each occurrence involving a loss of coolant circulation. Furthermore, verification of the functioning of the alternate method must be reconfirmed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter. This will provide assurance of continued temperature monitoring capability.

During the period when the reactor coolant is being circulated by an alternate method (other than by the required RHR shutdown cooling subsystem or recirculation pump), the reactor coolant temperature and pressure must be periodically monitored to ensure proper function of the alternate method. The once per hour Completion Time is deemed appropriate.

SURVEILLANCE REQUIREMENTS SR 3.4.7.1 This Surveillance verifies that one RHR shutdown cooling subsystem or recirculation pump is in operation and circulating reactor coolant. The required flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

Cooper B 3.4-38 01/06/21

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