CNRO-2020-00008, Application to Revise Technical Specifications to Adopt TSTF-566, Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems Using the Consolidated Line Item Improvement Process

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Application to Revise Technical Specifications to Adopt TSTF-566, Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems Using the Consolidated Line Item Improvement Process
ML20024F216
Person / Time
Site: Grand Gulf, River Bend  Entergy icon.png
Issue date: 01/24/2020
From: Gaston R
Entergy Operations
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
CNRO-2020-00008
Download: ML20024F216 (47)
v • d • e


Text

Entergy Operations, Inc.

1340 Echelon Parkway Jackson, MS 39213 Tel 601-368-5138 Ron Gaston Director, Nuclear Licensing 10 CFR 50.90 CNRO-2020-00008 January 24, 2020 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Application to Revise Technical Specifications to Adopt TSTF-566, "Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems" using the Consolidated Line Item Improvement Process Grand Gulf Nuclear Station, Unit 1 NRC Docket No. 50-416 Renewed Facility Operating License No. NPF-29 River Bend Station, Unit 1 NRC Docket No. 50-458 Renewed Facility Operating License No. NPF-47 In accordance with Title 10 of the Code of Federal Regulations (CFR) Part 50, Section 50.90, "Application for amendment of license, construction permit, or early site permit," Entergy Operations, Inc. (Entergy) is submitting a request for an amendment to Renewed Facility Operating License, Appendix A, "Technical Specifications" (TS) for Grand Gulf Nuclear Station, Unit 1 (GGNS) and River Bend Station, Unit 1 (RBS).

These proposed changes adopt the U.S. Nuclear Regulatory Commission (NRC)-approved Technical Specification Task Force (TSTF) Traveler TSTF-566, "Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems," Revision 2 into the GGNS TS and the RBS TS. The proposed amendment revises the TS actions that are applicable when a residual heat removal (RHR) shutdown cooling subsystem is inoperable.

The Enclosure to this letter provides a description and assessment of the proposed changes.

Attachments 1.a and 1.b to the Enclosure provide the existing TS pages for GGNS and RBS, respectively, marked-up to show the proposed changes. Attachments 2.a and 2.b provide revised (clean) TS pages. Attachments 3.a and 3.b provide, for information only, marked up versions of existing TS Bases pages to show the proposed changes.

Entergy requests approval of the proposed license amendment by February 24, 2021. The proposed changes would be implemented within 90 days of issuance of the amendment.

Enclosure CNRO-2020-00008 Description and Assessment of the Proposed Changes Application to Revise Technical Specifications to Adopt TSTF-566, "Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems" Grand Gulf Nuclear Station, Unit 1 River Bend Station, Unit 1 (3 Pages) 1.0 Description 2.0 Assessment 2.1 Applicability of Published Safety Evaluation 2.2 Variations 2.3 Precedent 3.0 Regulatory Analysis 3.1 No Significant Hazards Determination 3.2 Precedent 3.3 Conclusion 4.0 Environmental Consideration 5.0 References

CNRO-2020-00008 Enclosure Page 1 of 3

1.0 DESCRIPTION

Entergy Operations, Inc. (Entergy) requests adoption of Technical Specification Task Force (TSTF) Traveler TSTF-566, "Revise Actions for Inoperable RHR-Shutdown Cooling Subsystems," (Reference 1) which is an approved change to the Improved Standard Technical Specifications (ISTS), into the Grand Gulf Nuclear Station, Unit 1 (GGNS) and River Bend Station, Unit 1 (RBS) Technical Specifications (TS). The proposed amendment revises the TS actions applicable when a residual heat removal (RHR) shutdown cooling subsystem is inoperable.

2.0 ASSESSMENT 2.1 Applicability of Safety Evaluation Entergy has reviewed the U.S. Nuclear Regulatory Commission (NRC) safety evaluation (SE) for TSTF-566 provided to the TSTF by letter dated February 21, 2019 (ADAMS Accession No. ML19028A285). This review included a review of the NRC's SE (ADAMS Accession No. ML19028A287), as well as the information provided in TSTF-566. Entergy has concluded that the justifications presented in TSTF-566 and the SE prepared by the NRC are applicable to GGNS and RBS and justify this amendment for the incorporation of the changes to the GGNS and RBS TS.

2.2 Variations Entergy is not proposing any variations from the TS changes described in TSTF-566 or the applicable parts of the NRC SE dated February 21, 2019.

3.0 Regulatory Analysis 3.1 No Significant Hazards Consideration Analysis Entergy Operations Inc. (Entergy) requests adoption of TSTF-566, "Revise Actions for Inoperable RHR Shutdown Cooling Systems," which is a Nuclear Regulatory Commission (NRC)- approved change to ISTS, into the Grand Gulf Nuclear Station, Unit 1 (GGNS) and River Bend Station, Unit 1 (RBS) Technical Specifications (TS). The proposed amendment revises the TS actions applicable when a residual heat removal (RHR) shut down cooling subsystem is inoperable.

Entergy has evaluated whether or not a significant hazards consideration is involved with the proposed amendments by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment, as discussed below:

CNRO-2020-00008 Enclosure Page 2 of 3

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

Response: No The proposed changes revise the actions to be taken when an RHR shutdown cooling subsystem is 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 changes. Therefore, the proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

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

Response: No The proposed changes revise the actions to be taken when an RHR shutdown cooling subsystem is inoperable. The proposed change does not affect the design function or operation of the RHR shutdown cooling subsystems. No new equipment is being installed as a result of the proposed change. The proposed change only affects the actions taken when an RHR shutdown cooling subsystem is inoperable, so no new failure mechanisms are created.

Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any previously evaluated.

3. Do the proposed amendments involve a significant reduction in a margin of safety?

Response: No The proposed change revises the actions to be taken when an RHR shutdown cooling subsystem is 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 RHR System in the shutdown cooling mode removes decay heat from the reactor coolant system during shutdown. The proposed changes do not affect any design or safety limits associated with the RHR System.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Based on the above, Entergy concludes that the proposed changes present no significant hazards consideration under the standards set forth in 10 CFR 50.92(c),

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

CNRO-2020-00008 Enclosure Page 3 of 3 3.2 Precedent The proposed change is consistent with the NRC-approved license amendments issued to Southern Nuclear Operating Company on November 13, 2019 for Edwin I. Hatch Nuclear Plant, Unit Nos. 1 and 2 (Amendment Numbers 300 and 245, respectively) (ADAMS Accession No. ML19267A023).

3.3 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 amendments will not be inimical to the common defense and security or to the health and safety of the public.

4.0 Environmental Consideration The proposed changes 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 changes do 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 changes meet 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 changes.

5.0 References 5.1 Technical Specification Task Force (TSTF) Traveler 566, "Residual Heat Removal,"

Revision 4, (ADAMS Accession No. ML18299A048).

Attachment 1.a CNRO-2020-00008 Markup of Technical Specification (TS) Pages Grand Gulf Nuclear Station, Unit 1 TS Pages 3.4-21 3.4-22 3.4-24*

3.4-25

  • TS Page 3.4-24 provided for reference only; no changes on page

RHR Shutdown Cooling System Hot Shutdown 3.4.9 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.9 Residual Heat Removal (RHR) Shutdown Cooling System Hot Shutdown LCO 3.4.9 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 not be in 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 cut in 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 A.1 Initiate action to restore Immediately shutdown cooling RHR shutdown cooling subsystems inoperable. subsystem(s) to OPERABLE status.

AND (continued)

GRAND GULF 3.4-21 Amendment No. 142, 175

RHR Shutdown Cooling System Hot Shutdown 3.4.9 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. (continued) A.21 Verify an alternate 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> method of decay heat 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 AND A.3 Be in MODE 4.

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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.

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

No recirculation pump AND in operation.

BC.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 BC.3 Monitor reactor coolant Once per hour temperature and pressure.

GRAND GULF 3.4-22 Amendment No. 120

No Changes Included for information only RHR Shutdown Cooling System Cold Shutdown 3.4.10 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.10 Residual Heat Removal (RHR) Shutdown Cooling System Cold Shutdown LCO 3.4.10 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 not be in 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 />.
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.
3. Both RHR shutdown cooling subsystems and recirculation pumps may not be in operation during RCS inservice leak and hydrostatic testing.

APPLICABILITY: MODE 4.

ACTIONS

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

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

CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR 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 /> shutdown cooling method of decay heat subsystems inoperable. removal is available for AND each inoperable RHR shutdown cooling Once per subsystem. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter (continued)

GRAND GULF 3.4-24 Amendment No. 120, 142

RHR Shutdown Cooling System Cold Shutdown 3.4.10 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME 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.

BC. No RHR shutdown BC.1 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 cooling subsystem in circulating by an of no reactor coolant operation. alternate method. circulation AND AND No recirculation pump in Once per operation. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND BC.2 Monitor reactor coolant Once per hour temperature and pressure.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.10.1 Verify one RHR shutdown cooling subsystem or In accordance with recirculation pump is operating. the Surveillance Frequency Control Program SR 3.4.10.2 Verify RHR shutdown cooling subsystem locations In accordance with susceptible to gas accumulation are sufficiently the Surveillance filled with water. Frequency Control Program GRAND GULF 3.4-25 Amendment No. 120, 202, 219

Attachment 1.b CNRO-2020-00008 Markup of Technical Specification (TS) Pages River Bend Station, Unit 1 TS Pages 3.4-22 3.4-23 3.4-25*

3.4-26

  • TS Page 3.4-25 provided for reference only; no changes on page

RHR Shutdown Cooling System - Hot Shutdown 3.4.9 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.9 Residual Heat Removal (RHR) Shutdown Cooling System Hot Shutdown LCO 3.4.9 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 cut in 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 Initiate action to restore Immediately cooling subsystems RHR shutdown cooling inoperable. subsystem(s) to OPERABLE status.

AND (continued)

(continued)

RIVER BEND 3.4-22 Amendment No. 81, 156

RHR Shutdown Cooling System - Hot Shutdown 3.4.9 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME A. (continued) A.2 Verify an alternate 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> method of decay heat Move 1 removal is available for AND to each inoperable RHR Page shutdown cooling Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 3.4-22 subsystem. thereafter AND A.3 Be in MODE 4. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> B. No RHR shutdown cooling B.1 Initiate action to restore Immediately subsystem in operation. one RHR shutdown C C cooling subsystem or AND one recirculation pump to operation.

No recirculation pump in operation. AND B.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 discovery of no C alternate 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 B.3 Monitor reactor coolant Once per hour temperature and C pressure.

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.

RIVER BEND 3.4-23 Amendment No. 81

RHR Shutdown Cooling System - Cold Shutdown No Changes 3.4.10 Included for information only 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.10 Residual Heat Removal (RHR) Shutdown Cooling System Cold Shutdown LCO 3.4.10 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.
3. Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation during RCS inservice leak and hydrostatic testing.

APPLICABILITY: MODE 4.

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 method 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> cooling subsystems of decay heat removal is 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 (continued)

RIVER BEND 3.4-25 Amendment No. 81

RHR Shutdown Cooling System - Cold Shutdown 3.4.10 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPELETION TIME B. No RHR shutdown cooling B.1 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 subsystem in operation. circulating by an of no reactor coolant alternate method. circulation C AND C AND No recirculation pump in operation. Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND B.2 Monitor reactor coolant Once per hour temperature and pressure.

C SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.10.1 Verify one RHR shutdown cooling subsystem or In accordance with recirculation pump is operating. the Surveillance Frequency Control Program SR 3.4.10.2 Verify RHR shutdown cooling subsystem locations In accordance with susceptible to gas accumulation are sufficiently filled the Surveillance with water. Frequency Control Program 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 RIVER BEND 3.4-26 Amendment No. 81, 188, 196

Attachment 2.a CNRO-2020-00008 Clean Technical Specification (TS) Pages Grand Gulf Nuclear Station, Unit 1 TS Pages 3.4-21 3.4-22 3.4-25

RHR Shutdown Cooling System Hot Shutdown 3.4.9 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.9 Residual Heat Removal (RHR) Shutdown Cooling System Hot Shutdown LCO 3.4.9 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 not be in 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 cut in 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 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 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 (continued)

GRAND GULF 3.4-21 Amendment No. 142, 175

RHR Shutdown Cooling System Hot Shutdown 3.4.9 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME 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.

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

No recirculation pump AND in operation.

C.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 C.3 Monitor reactor coolant Once per hour temperature and pressure.

GRAND GULF 3.4-22 Amendment No. 120

RHR Shutdown Cooling System Cold Shutdown 3.4.10 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME 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.

C. No RHR shutdown C.1 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 cooling subsystem in circulating by an of no reactor coolant operation. alternate method. circulation AND AND No recirculation pump in Once per operation. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND C.2 Monitor reactor coolant Once per hour temperature and pressure.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.10.1 Verify one RHR shutdown cooling subsystem or In accordance with recirculation pump is operating. the Surveillance Frequency Control Program SR 3.4.10.2 Verify RHR shutdown cooling subsystem locations In accordance with susceptible to gas accumulation are sufficiently the Surveillance filled with water. Frequency Control Program GRAND GULF 3.4-25 Amendment No. 120, 202, 219

Attachment 2.b CNRO-2020-00008 Clean Technical Specification (TS) Pages River Bend Station, Unit 1 TS Pages 3.4-22 3.4-23 3.4-26

RHR Shutdown Cooling System - Hot Shutdown 3.4.9 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.9 Residual Heat Removal (RHR) Shutdown Cooling SystemHot Shutdown LCO 3.4.9 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 cut in 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 (continued)

RIVER BEND 3.4-22 Amendment No. 81, 156

RHR Shutdown Cooling System - Hot Shutdown 3.4.9 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME 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.

C. No RHR shutdown cooling C.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 C.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 discovery of no alternate 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 C.3 Monitor reactor coolant Once per hour temperature and pressure.

RIVER BEND 3.4-23 Amendment No. 81

RHR Shutdown Cooling System - Cold Shutdown 3.4.10 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPELETION TIME B. Required Action and B.1 Initiate action to Immediately associated Completion restore RHR Time of Condition A not shutdown cooling met. subsystem(s) to OPERABLE status.

C. No RHR shutdown cooling C.1 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 subsystem in operation. circulating by an of no reactor coolant alternate method. circulation AND AND No recirculation pump in operation. Once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thereafter AND C.2 Monitor reactor coolant Once per hour temperature and pressure.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.10.1 Verify one RHR shutdown cooling subsystem or 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> recirculation pump is operating.

SR 3.4.10.2 Verify RHR shutdown cooling subsystem locations 31 days susceptible to gas accumulation are sufficiently filled with water.

RIVER BEND 3.4-26 Amendment No. 81, 188

Attachment 3.a CNRO-2020-00008 Markup of Technical Specification (TS) Bases Pages, For Information Only Grand Gulf Nuclear Station, Unit 1 TS Bases Pages B 3.4-44 B 3.4-45 B 3.4-49*

B 3.4-50 B3.9-27 B3.9-31

  • TS Bases Page B 3.4-49 provided for reference only; no changes on page

Attachment 3.b CNRO-2020-00008 Markup of Technical Specification (TS) Bases Pages, For Information Only River Bend Station, Unit 1 TS Bases Pages B 3.4-45 B 3.4-46 B 3.4-47 B 3.4-50*

B 3.4-51 B 3.9-26*

B 3.9-27 B 3.9-30*

B3.9-31

  • TS Bases Pages B 3.4-50, B 3.9-26, and B 3.9-30 provided for reference only; no changes on pages

RHR Shutdown Cooling System Hot Shutdown B 3.4.9 BASES APPLICABILITY The requirements for decay heat removal in MODES 4 and 5 are (continued) discussed in LCO 3.4.10, "Residual Heat Removal (RHR) Shutdown Cooling System - Cold Shutdown"; LCO 3.9.8, "Residual Heat Removal (RHR) - High Water Level"; and LCO 3.9.9, "Residual Heat Removal (RHR) - Low Water Level."

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, A.2, and A.3 With one required RHR shutdown cooling subsystem inoperable for decay heat removal, except as permitted by LCO Note 2, the inoperable subsystem must be restored to OPERABLE status without delay. In this condition, the remaining OPERABLE subsystem can provide the necessary decay heat removal. Tthe 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.

(continued)

RIVER BEND B 3.4-45 Revision No. 133

RHR Shutdown Cooling System Hot Shutdown B 3.4.9 BASES ACTIONS A.1, A.2, and A.3 (continued)

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

the functional availability of This re-establishes backup decay heat removal capabilities, similar to the these alternate method(s) 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 must be reconfirmed every decay heat removal function and the probability of a loss of the available 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This decay heat removal capabilities.

will provide assurance of continued heat removal The required cooling capacity of the alternate method should be sufficient capability. to ensured by verifying (by calculation or demonstration) its capability 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 Control Rod Drive System, or the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.

However, due to the potentially reduced reliability of the alternate methods of decay heat removal, it is also required to reduce the reactor coolant temperature to the point where MODE 4 is entered.

Insert A CB.1, CB.2, and CB.3 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as is permitted by LCO Note 1, reactor coolant circulation by the RHR shutdown cooling subsystem or one 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.

(continued)

RIVER BEND B 3.4-46 Revision No. 0

Insert A 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.

RHR Shutdown Cooling System Hot Shutdown B 3.4.9 BASES C ACTIONS B.1, B.2, and B.3 (continued)

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 3.4.9.1 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.

This Surveillance is modified by a Note allowing sufficient time to align the RHR System for shutdown cooling operation after clearing the pressure interlock that isolates the system, or for placing a recirculation pump in operation. The Note takes exception to the requirements of the Surveillance being met (i.e., forced coolant circulation is not required for this initial 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> period), which also allows entry into the Applicability of this Specification in accordance with SR 3.0.4 since the Surveillance will not be "not met" at the time of entry into the Applicability.

SR 3.4.9.2 RHR Shutdown Cooling System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managing gas intrusion and accumulation is necessary for proper operation of the RHR shutdown cooling subsystems and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.

Selection of RHR Shutdown Cooling System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations. The design review is supplemented by system walk downs to validate the system high points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration.

(continued)

RIVER BEND B 3.4-47 Amendment No. 196

No Changes RHR Shutdown Cooling System Cold Shutdown Included for information only B 3.4.10 BASES APPLICABILITY In Mode 4, the RHR System may be operated in the shutdown cooling (continued) mode to remove decay heat to maintain coolant temperature below 200 F. Otherwise, a recirculation pump is required to be in operation.

The requirements for decay heat removal in MODE 3 below the cut in permissive pressure and in MODE 5 are discussed in LCO 3.4.9, "Residual Heat Removal (RHR) Shutdown Cooling System Hot Shutdown"; LCO 3.9.8, "Residual Heat Removal (RHR) High Water Level"; and LCO 3.9.9, "Residual Heat Removal (RHR) Low Water Level."

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 of the two required RHR shutdown cooling subsystems inoperable, except as permitted by LCO Note 2, the remaining subsystem is capable of providing the required decay heat removal. However, the overall reliability is reduced. 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 (continued)

RIVER BEND B 3.4-50 Revision No. 0

RHR Shutdown Cooling System Cold Shutdown B 3.4.10 BASES ACTIONS A.1 (continued) 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 ensured by verifying (by calculation or demonstration) its capability 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 Control Rod Drive System, or the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.

Insert B CB.1 and CB.2 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as is permitted by LCO Note 1, and 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 System 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 3.4.10.1 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 (continued)

RIVER BEND B 3.4-51 Revision No. 0

Insert B 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.

No Changes RHR High Water Level Included for information only B 3.9.8 BASES LCO An OPERABLE RHR shutdown cooling subsystem consists of an RHR (continued) pump, two heat exchangers, valves, piping, instruments, and controls to ensure an OPERABLE flow path. Management of gas voids is important to RHR Shutdown Cooling System OPERABILITY.

Additionally, each RHR shutdown cooling subsystem is considered OPERABLE if it can be manually aligned (remote or local) in the shutdown cooling mode for removal of decay heat. Operation (either continuous or intermittent) of one subsystem can maintain and reduce the reactor coolant temperature as required. However, to ensure adequate core flow to allow for accurate average reactor coolant temperature monitoring, nearly continuous operation is required. A Note is provided to allow a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> exception to shut down the operating subsystem every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

APPLICABILITY One RHR shutdown cooling subsystem must be OPERABLE in MODE 5, with irradiated fuel in the RPV and the water level 23 ft above the top of the RPV flange, to provide decay heat removal. RHR System requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS); Section 3.5, Emergency Core Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC) System; and Section 3.6, Containment Systems. RHR Shutdown Cooling System requirements in MODE 5, with the water level < 23 ft above the RPV flange, are given in LCO 3.9.9, "Residual Heat Removal (RHR) -Low Water Level."

ACTIONS A.1 With no RHR shutdown cooling subsystem OPERABLE, an alternate method of decay heat removal must be established within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. In this condition, the volume of water above the RPV flange provides adequate capability to remove decay heat from the reactor core. However, the overall reliability is reduced because loss of water level could result in reduced decay heat removal capability. 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 ensure continued heat removal capability.

(continued)

RIVER BEND B 3.9-26 Revision No. 163

RHR High Water Level B 3.9.8 BASES ACTIONS A.1 (continued)

Alternate decay heat removal methods are available to the operators for review and preplanning in the unit's Operating Procedures. Examples include, but are not limited to, the use of the Reactor Water Cleanup System, operating with the regenerative heat exchanger bypassed, or operation of the Suppression Pool Cleanup, Cooling, and Alternate Decay Heat Removal System in the reactor to reactor, reactor to upper pool, or upper pool to reactor Alternate Decay Heat Removal configurations. The method used to remove the decay heat should be the most prudent choice based on unit conditions.

Caution should be exercised when determining appropriate instrumentation for Reactor Coolant System (RCS) temperature monitoring. During periods of high decay heat and reduced circulation, limitations may exist for specific temperature instrumentation. For example, the indication of temperature provided by the Reactor Water Cleanup System (RWCU) can potentially mislead operators into thinking that coolant temperature is significantly lower than actual. This condition may occur any time the Reactor Recirculation is out of service, and normal decay heat removal systems are lost or intentionally turned off, especially during periods of high decay heat load.

B.1, B.2, and B.3 If no RHR shutdown cooling subsystem is OPERABLE and an alternate method of decay heat removal is not available in accordance with Required Action A.1, actions shall be taken immediately to suspend operations involving an increase in reactor decay heat load by suspending the loading of irradiated fuel assemblies into the RPV.

Additional actions are required to minimize any potential fission product release to the environment. This includes initiating immediate action to restore primary containment to OPERABLE status. The closed air lock door completes the boundary for control of potential radioactive releases.

With the appropriate administrative controls however, the closed door can be opened intermittently for entry and exit.

(continued)

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 Spent Fuel Pool Cooling System, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.

RIVER BEND B 3.9-27 Revision No. 4-2

No Changes RHR -Low Water Level B 3.9.9 Included for information only BASES LCO Additionally, each RHR shutdown cooling subsystem is considered (continued) OPERABLE if it can be manually aligned (remote or local) in the shutdown cooling mode for removal of decay heat. Operation (either continuous or intermittent) of one subsystem can maintain and reduce the reactor coolant temperature as required. However, to ensure adequate core flow to allow for accurate average reactor coolant temperature monitoring, nearly continuous operation is required. A Note is provided to allow a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> exception to shut down the operating subsystem every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

APPLICABILITY Two RHR shutdown cooling subsystems are required to be OPERABLE in MODE 5, with irradiated fuel in the RPV and the water level < 23 ft above the top of the RPV flange, to provide decay heat removal. RHR System requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS); Section 3.5, Emergency Core Cooling Systems (ECCS) and Reactor Core Isolation Cooling (RCIC)

System; and Section 3.6, Containment Systems. RHR Shutdown Cooling System requirements in MODE 5, with the water level 23 ft above the RPV flange, are given in LCO 3.9.8, "Residual Heat Removal (RHR) -High Water Level."

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 of the two required RHR shutdown cooling subsystems inoperable, the remaining subsystem is capable of providing the required decay heat removal. However, the overall (continued)

RIVER BEND B 3.9-30 Revision No. 0

RHR -Low Water Level B 3.9.9 BASES ACTIONS A.1 (continued) reliability is reduced. 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 ensure continued heat removal capability. Alternate decay heat removal methods are available to the operators for review and preplanning in the unit's Operating Procedures. Examples include, but are not limited to, the use of the Reactor Water Cleanup System, operating with the regenerative heat exchanger bypassed, or operation of the Suppression Pool Cleanup, Cooling, and Alternate Decay Heat Removal System in the reactor to reactor, reactor to upper pool, or upper pool to reactor Alternate Decay Heat Removal configurations. The method used to remove decay heat should be the most prudent choice based on unit conditions.

Caution should be exercised when determining appropriate instrumentation for Reactor Coolant System (RCS) temperature monitoring. During periods of high decay heat and reduced circulation, limitations may exist for specific temperature instrumentation. For example, the indication of temperature provided by the Reactor Water Cleanup System (RWCU) can potentially mislead operators into thinking that coolant temperature is significantly lower than actual. This condition may occur any time the Reactor Recirculation is out of service, and normal decay heat removal systems are lost or intentionally turned off, especially during periods of high decay heat load.

B.1 and B.2 With the required RHR shutdown cooling subsystem(s) inoperable and the required alternate method(s) of decay heat removal not available in accordance with Required Action A.1, additional actions are required to minimize any (continued)

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 Spent Fuel Pool Cooling System, the Reactor Water Cleanup System, or an inoperable but functional RHR shutdown cooling subsystem.

RIVER BEND B 3.9-31 Revision No. 4-2

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