NL-21-1037, License Amendment Request to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling

From kanterella
Jump to navigation Jump to search

License Amendment Request to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling
ML22038A205
Person / Time
Site: Hatch  Southern Nuclear icon.png
Issue date: 02/04/2022
From: Gayheart C
Southern Nuclear Operating Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-21-1037, TSTF-580
Download: ML22038A205 (23)
v • d • e


Text

3535 Colonnade Parkway Cheryl A. Gayheart Birmingham, AL 35243 Regulatory Affairs Director 205 992 5316 cagayhea@southernco.com February 4, 2022 NL-21-1037 Docket Nos. 50-321 50-366 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant - Units 1 and 2 License Amendment Request to Revise Technical Specifications to Adopt TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling" Pursuant to 10 CFR 50.90, Southern Nuclear Operating Company (SNC) hereby requests a license amendment to Edwin I. Hatch Nuclear Plant (HNP) Units 1 and 2 Renewed Facility Operating Licenses DPR-57 and NPF-5, respectively.

SNC requests adoption of TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling." The proposed change provides a Technical Specification (TS) exception to entering Mode 4 if both required Residual Heat Removal (RHR) shutdown cooling subsystems are inoperable.

The enclosure provides a description and assessment of the proposed changes. Attachment 1 provides the existing TS pages marked to show the proposed changes. Attachment 2 provides clean typed TS pages. Attachment 3 provides the existing TS Bases pages marked to show the revised text associated with the proposed TS changes and is provided for information only.

SNC requests that the amendment be reviewed under the Consolidated Line Item Improvement Process (CLIIP). Approval of the proposed amendment is requested within six months of completion of the NRCs acceptance review. Once approved, the amendment shall be implemented within 90 days.

In accordance with 10 CFR 50.91, a copy of this application is being provided to the designated Georgia Official.

This letter contains no regulatory commitments. If you have any questions, please contact Ryan Joyce at 205.992.6468.

U.S. Nuclear Regulatory Commission NL-21-1037 Page 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 4th day of February 2022.

Respectfully submitted, Cheryl A. Gayheart Regulatory Affairs Director Southern Nuclear Operating Company CAG/tle

Enclosure:

Description and Assessment Attachments: 1. Proposed Technical Specifications Changes (Mark-Up)

2. Revised Technical Specification Pages
3. Proposed Technical Specifications Bases Changes (Mark-Up) - For Information Only cc: Regional Administrator, Region II NRR Project Manager - Hatch Senior Resident Inspector - Hatch Director, Environmental Protection Division - State of Georgia RType: CHA02.004

ENCLOSURE Edwin I. Hatch Nuclear Plant - Units 1 and 2 Application to Revise Technical Specifications to Adopt TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling" Description and Assessment

Description and Assessment

1.0 DESCRIPTION

Southern Nuclear Operating Company (SNC) hereby requests a license amendment to Edwin I.

Hatch Nuclear Plant (HNP) Units 1 and 2 Renewed Facility Operating Licenses DPR-57 and NPF-5, respectively.

SNC requests adoption of TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling." The proposed change provides a Technical Specification (TS) exception to entering Mode 4 if both required Residual Heat Removal (RHR) shutdown cooling subsystems are inoperable.

Associated TS Bases are revised to reflect these TS changes.

2.0 ASSESSMENT 2.1 Applicability of Safety Evaluation SNC has reviewed the safety evaluation for TSTF-580 provided to the Technical Specifications Task Force in a letter dated July 11, 2021. This review included a review of the NRC staffs evaluation, as well as the information provided in TSTF-580. SNC has concluded that the justifications presented in TSTF-580 and the safety evaluation prepared by the NRC staff are applicable to HNP Units 1 and 2 and justify this amendment for the incorporation of the changes to the HNP TS.

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

was approved by the NRC for HNP Units 1 and 2 on November 13, 2019 (ML19267A023).

2.2 Optional Changes and Variations SNC is not proposing any variations from the TS changes described in TSTF-580 or the applicable parts of the NRC staffs safety evaluation dated July 11, 2021.

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

3.0 REGULATORY ANALYSIS

3.1 No Significant Hazards Consideration Analysis Southern Nuclear Operating Company (SNC) requests adoption of TSTF-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.

SNC 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:

E-1

Description and Assessment

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 (LPCI) 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 actions taken when both required RHR shutdown cooling subsystems are inoperable, so no new failure mechanisms are created.

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 E-2

Description and Assessment 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, SNC 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 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.

4.0 ENVIRONMENTAL EVALUATION 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 a 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.

E-3

Edwin I. Hatch Nuclear Plant - Units 1 and 2 Application to Revise Technical Specifications to Adopt TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling" Attachment 1 Proposed Technical Specification Changes (Mark-Up)

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 performance of Surveillances.

APPLICABILITY: MODE 3 with reactor steam dome pressure less than the RHR low pressure permissive pressure.

ACTIONS

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

Separate Condition entry is allowed for each RHR shutdown cooling subsystem.

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

(continued)

HATCH UNIT 1 3.4-13 Amendment No. 300

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

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

associated Completion LCO 3.0.3 and all other LCO Time of Condition C not Required Actions requiring a met. 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.

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

No recirculation pump in operation. AND EC.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 discovery circulation by an of no reactor coolant alternate method. 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 EC.3 Monitor reactor coolant Once per hour temperature and pressure.

HATCH UNIT 1 3.4-14 Amendment No. 300

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 performance of Surveillances.

APPLICABILITY: MODE 3 with reactor steam dome pressure less than the RHR low pressure permissive pressure.

ACTIONS

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

Separate Condition entry is allowed for each RHR shutdown cooling subsystem.

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

(continued)

HATCH UNIT 2 3.4-13 Amendment No. 245

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

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

associated Completion LCO 3.0.3 and all other LCO Time of Condition C not Required Actions requiring a met. 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.

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

No recirculation pump in operation. AND EC.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 discovery circulation by an of no reactor coolant alternate method. 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 EC.3 Monitor reactor coolant Once per hour temperature and pressure.

HATCH UNIT 2 3.4-14 Amendment No. 245

Edwin I. Hatch Nuclear Plant - Units 1 and 2 Application to Revise Technical Specifications to Adopt TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling" Attachment 2 Revised Technical Specification Pages

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 performance of Surveillances.

APPLICABILITY: MODE 3 with reactor steam dome pressure less than the RHR low pressure permissive pressure.

ACTIONS

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

Separate Condition entry is allowed for each RHR shutdown cooling subsystem.

CONDITION REQUIRED ACTION COMPLETION TIME A. One RHR shutdown A.1 Verify an alternate 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> cooling subsystem method of decay heat inoperable. removal is 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 RHR shutdown cooling Time of Condition A not subsystem to met. OPERABLE status.

(continued)

HATCH UNIT 1 3.4-13 Amendment No.

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

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

associated Completion LCO 3.0.3 and all other LCO Time of Condition C not Required Actions requiring a met. 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 AND one 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 discovery circulation by an of no reactor coolant alternate method. 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.

HATCH UNIT 1 3.4-14 Amendment No.

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 performance of Surveillances.

APPLICABILITY: MODE 3 with reactor steam dome pressure less than the RHR low pressure permissive pressure.

ACTIONS

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

Separate Condition entry is allowed for each RHR shutdown cooling subsystem.

CONDITION REQUIRED ACTION COMPLETION TIME A. One RHR shutdown A.1 Verify an alternate 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> cooling subsystem method of decay heat inoperable. removal is 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 RHR shutdown cooling Time of Condition A not subsystem to met. OPERABLE status.

(continued)

HATCH UNIT 2 3.4-13 Amendment No.

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

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

associated Completion LCO 3.0.3 and all other LCO Time of Condition C not Required Actions requiring a met. 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 AND one 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 discovery circulation by an of no reactor coolant alternate method. 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.

HATCH UNIT 2 3.4-14 Amendment No.

Edwin I. Hatch Nuclear Plant - Units 1 and 2 Application to Revise Technical Specifications to Adopt TSTF-580, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling" Attachment 3 Proposed Technical Specification Bases Changes (Mark-Up)

For Information Only

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

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.

A.1 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 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 Condensate/Main Steam Systems, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.

(continued)

HATCH UNIT 1 B 3.4-31 REVISION 106

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

ACTIONS B.1 If required alternate method(s) of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystem(s) 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 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 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 HATCH UNIT 1 B 3.4-32 REVISION 106

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

EC.1, EC.2, and EC.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 SR 3.4.7.1 REQUIREMENTS 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.

(continued)

HATCH UNIT 1 B 3.4-33 REVISION 106

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

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.

A.1 With one required RHR shutdown cooling subsystem inoperable for decay heat removal, except as permitted by LCO Note 2, the overall reliability is reduced, however, 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 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 Condensate/Main Steam Systems, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.

(continued)

HATCH UNIT 2 B 3.4-32 REVISION 118

RHR Shutdown Cooling System - Hot Shutdown B 3.4.7 BASES ACTIONS B.1 If the required alternate method(s) of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystem(s) 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 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 (continued)

HATCH UNIT 2 B 3.4-33 REVISION 118

RHR Shutdown Cooling System - Hot Shutdown B 3.4.7 BASES ACTIONS cooling subsystems before 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.

EC.1, EC.2, and EC.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 SR 3.4.7.1 REQUIREMENTS 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.

(continued)

HATCH UNIT 2 B 3.4-34 REVISION 118

Retrieved from "https://kanterella.com/w/index.php?title=NL-21-1037,_License_Amendment_Request_to_Revise_Technical_Specifications_to_Adopt_TSTF-580,_Provide_Exception_from_Entering_Mode_4_with_No_Operable_RHR_Shutdown_Cooling&oldid=3427171"