L-MT-24-026, Application to Revise Technical Specifications to Adopt TSTF-566, Revise Actions for Inoperable RHR Shutdown Cooling Subsystems, and TSTF-580, Revision 1, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling, Usin
| ML24327A157 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 10/21/2024 |
| From: | Hafen S Northern States Power Company, Minnesota, Xcel Energy |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| L-MT-24-026 | |
| Download: ML24327A157 (1) | |
Text
(},, Xcel Energy*
October 21, 2024 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket No. 50-263 Renewed Facility Operating License No. DPR-22 2807 West County Road 7 5 Monticello, MN 55089 L-MT-24-026 10 CFR 50.90 Application to Revise Technical Specifications to Adopt TSTF-566, "Revise Actions for Inoperable RHR Shutdown Cooling Subsystems," and TSTF-580, Revision 1, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling," Using the Consolidated Line Item Improvement Process Pursuant to 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," the Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), is submitting a request for an amendment to the Technical Specifications (TS) for the Monticello Nuclear Generating Plant (MNGP).
NSPM requests adoption of Technical Specification Task Force (TSTF) travelers TSTF-566, "Revise Actions for Inoperable RHR [Residual Heat Removal] Shutdown Cooling Subsystems,"
and TSTF-580, Revision 1, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling," which are approved changes to the Improved Standard Technical Specifications (ISTS), into the MNGP TS. The proposed amendment revises the TS actions applicable when a residual heat removal shutdown cooling subsystem is inoperable and provides a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable. This change is requested as part of the Consolidated Line Item Improvement Process (CLIIP).
The enclosure provides a description and assessment of the proposed changes. Attachment 1 to the enclosure provides the existing TS pages marked to show the proposed changes. to the enclosure provides the existing TS Bases pages marked to show the proposed changes for information only.
Approval of the proposed amendment is requested within six months following completion of U.S. Nuclear Regulatory Commission (NRC) acceptance review. Once approved, the amendment shall be implemented within 120 days.
In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"
paragraph (b), a copy of this application, with attachments, is being provided to the designated State of Minnesota official.
Document Control Desk L-MT-24-026 Page 2 of 2 If there are any questions or if additional information is needed, please contact Mr. Richard Loeffler at (612) 539-3370 or Rick.A.Loeffler@xcelenergy.com.
Summary of Commitments This letter makes no new commitments and no revisions to any existing commitments.
I declare, under penalty of perjury, that the foregoing is true and correct. Executed on October&, 2024.
Shawn Hafen Site Vice Pr.
ident, Monticello Nuclear Generating Plant Northern States Power Company - Minnesota Attachments cc:
Administrator, Region Ill, US NRC Project Manager, Monticello, US NRC Resident Inspector, Monticello, US NRC State of Minnesota
L-MT-24-026 NSPM Page 1 of 1 APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT TSTF-566, "REVISE ACTIONS FOR INOPERABLE RHR SHUTDOWN COOLING SUBSYSTEMS,"
AND TSTF-580, REVISION 1, "PROVIDE EXCEPTION FROM ENTERING MODE 4 WITH NO OPERABLE RHR SHUTDOWN COOLING," USING THE CONSOLIDATED LINE ITEM IMPROVEMENT PROCESS TABLE OF CONTENTS Enclosure
1.0 DESCRIPTION
..................................................................................................... 1
2.0 ASSESSMENT
..................................................................................................... 1 2.1 Applicability of the Safety Evaluations............................................................. 1 2.2 Variations........................................................................................................ 1
3.0 REGULATORY ANALYSIS
................................................................................... 2 3.1 Precedent........................................................................................................ 2 3.2 No Significant Hazards Consideration Analysis............................................... 2 3.3 Conclusion....................................................................................................... 4
4.0 ENVIRONMENTAL CONSIDERATION
................................................................ 5
6.0 REFERENCES
..5 Attachments (Att.)
Att. 1 Technical Specification Pages (Markup)
Att. 2 Technical Specification Bases Pages Markup (For Information)
L-MT-24-026 NSPM Enclosure Page 1 of 6 APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT TSTF-566, "REVISE ACTIONS FOR INOPERABLE RHR SHUTDOWN COOLING SUBSYSTEMS,"
AND TSTF-580, REVISION 1, "PROVIDE EXCEPTION FROM ENTERING MODE 4 WITH NO OPERABLE RHR SHUTDOWN COOLING," USING THE CONSOLIDATED LINE ITEM IMPROVEMENT PROCESS DESCRIPTION AND ASSESSMENT
1.0 DESCRIPTION
The Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), requests adoption of Technical Specification Task Force (TSTF) travelers TSTF-566, "Revise Actions for Inoperable RHR [Residual Heat Removal]
Shutdown Cooling Subsystems," and TSTF-580, Revision 1, "Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling," which are approved changes to the Improved Standard Technical Specifications (ISTS), into the Monticello Nuclear Generating Plant (MNGP) Technical Specifications (TS). The proposed amendment revises the TS actions applicable when a residual heat removal shutdown cooling subsystem is inoperable and provides a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable.
2.0 ASSESSMENT
2.1 Applicability of the Safety Evaluations NSPM has reviewed the safety evaluations for TSTF-566 and TSTF-580, Revision 1, provided to the TSTF in letters dated February 21, 2019, and July 11, 2021 (References 1 and 2),
respectively. This review included a review of the U. S. Nuclear Regulatory Commission (NRC) staff's evaluations, as well as the information provided within the NRC approved TSTF-566 and TSTF-580, Revision 1. As described herein, NSPM has concluded that the justifications presented in TSTF-566 and TSTF-580, Revision 1, and the safety evaluations prepared by the NRC staff are applicable to the MNGP and justify this amendment for the incorporation of the changes into the MNGP TS.
2.2 Variations TSTF-566 revises the Actions for Standard Technical Specifications (STS) Specification 3.4.8, "RHR Shutdown Cooling System - Hot Shutdown," and STS Specification 3.4.9, "RHR Shutdown Cooling System - Cold Shutdown." TSTF-580, Revision 1, makes further changes to the Actions of STS Specification 3.4.8 that were revised by TSTF-566, which is consistent with the staff's approval of TSTF-580, Revision 1. The TSTF-580, Revision 1, justification states that adoption is dependent on previous adoption of TSTF-566, which is satisfied by adopting both travelers.
L-MT-24-026 NSPM Enclosure Page 2 of 6 The MNGP TS utilize different numbering from the STS on which TSTF-566 and TSTF-580, Revision 1, were based. The following table lists the differences. These differences are administrative and do not affect the applicability of TSTF-566 and TSTF-580, Revision 1, to the MNGP TS.
Specification Title STS NUREG-1433 Spec. No.
Monticello TS Spec. No.
Residual Heat Removal (RHR) Shutdown Cooling System - Hot Shutdown 3.4.8 3.4.7 Residual Heat Removal (RHR) Shutdown Cooling System - Cold Shutdown 3.4.9 3.4.8 RHR - High Water Level B 3.9.8 B 3.9.7 RHR - Low Water Level B 3.9.9 B 3.9.8 to this enclosure provides the existing TS pages marked-up to show the proposed changes. Attachment 2 to this enclosure provides the marked-up TS Bases, for information.
3.0 REGULATORY ANALYSIS
3.1 Precedent This proposed license amendment request (LAR) is similar to the following NRC approved license amendments where both TSTF-566 and TSTF-580, Revision 1, were requested under the same LAR.
- 1. The Browns Ferry Nuclear Plant, Units 1, 2, and 3, each received an amendment in September 2023, revising the TS actions that are applicable when an RHR shutdown cooling subsystem is inoperable and to provide a TS exception to entering Mode 4 if both of the required RHR shutdown cooling subsystems were inoperable (Reference 3).
- 2. The Perry Nuclear Power Plant received an amendment in January 2022, revising the TS actions for inoperable residual heat removal (RHR) shutdown cooling subsystems in the RHR shutdown cooling system limiting conditions for operation (LCOs)
(Reference 4).
3.2 No Significant Hazards Consideration Analysis The Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), requests adoption of Technical Specification Task Force (TSTF) travelers TSTF-566, "Revise Actions for Inoperable RHR [Residual Heat Removal]
Shutdown Cooling Subsystems," and TSTF-580, Revision 1, "Provide Exception from Entering
L-MT-24-026 NSPM Enclosure Page 3 of 6 Mode 4 With No Operable RHR Shutdown Cooling," which are approved changes to the Improved Standard Technical Specifications (ISTS), into the Monticello Nuclear Generating Plant (MNGP) Technical Specifications (TS). The proposed amendment revises the TS actions applicable when a residual heat removal shutdown cooling subsystem is inoperable and provides a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable.
NSPM has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:
- 1.
Do the proposed changes 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 a 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.
The proposed changes 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 changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.
L-MT-24-026 NSPM Enclosure Page 4 of 6
- 2.
Do the proposed changes create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed changes revise the actions to be taken when a RHR shutdown cooling subsystem is inoperable. The proposed changes also provide a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable.
The proposed changes do 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 changes. The proposed changes only affect the actions taken when one or both RHR shutdown cooling subsystems are 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 accident previously evaluated.
- 3.
Do the proposed changes involve a significant reduction in a margin of safety?
Response: No The proposed changes revise the actions to be taken when a RHR shutdown cooling subsystem is inoperable and provides a TS exception to entering Mode 4 if both required RHR shutdown cooling subsystems are inoperable. The proposed changes do 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 changes. 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. The proposed changes also apply 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 changes do not involve a significant reduction in a margin of safety.
Based on the above, NSPM 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 hazards consideration" is justified.
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 Commission's
L-MT-24-026 NSPM Enclosure Page 5 of 6 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 CONSIDERATION
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, "Standards for Protection Against Radiation," 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, "Criteria for categorical exclusion; identification of licensing and regulatory actions eligible for categorical exclusion or otherwise not requiring environmental review," specifically paragraph (c)(9). Therefore, pursuant to 10 CFR 51.22(b),
no environmental impact statement or environmental assessment needs to be prepared in connection with the proposed changes.
5.0 REFERENCES
- 1.
Letter from the U.S. NRC to the Technical Specifications Task Force, "Final Safety Evaluations of Technical Specifications Task Force Traveller TSTF-566, Revision 0,
'Revise Actions for Inoperable RHR Shutdown Cooling Subsystems,' (EPID L-2018-PMP-0001)," dated February 21, 2019 (ADAMS Accession Numbers ML19028A285, ML19028A286 and ML19028A287)
- 2.
Letter from the U.S. NRC to the Technical Specifications Task Force, "Final Safety Evaluations of Technical Specifications Task Force Traveller TSTF-580, Revision 1,
'Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling,'
(EPID L-2020-PMP-0012)," dated July 11, 2021 (ADAMS Accession Numbers ML21188A278, ML21188A227 and ML21188A225)
- 3.
Letter from the U.S. NRC to the Tennessee Valley Authority, "Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Issuance of Amendment Nos. 332, 355, and 315 Regarding the Revision of Technical Specifications to Adopt TSTF-566-A, 'Revise Actions for Inoperable RHR Shutdown Cooling Subsystems,' and TSTF-580-A, Revision 1, 'Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling,'
(EPID L-2023-LLA-0035)," dated September 8, 2023 (ADAMS Accession Number ML23205A213)
L-MT-24-026 NSPM Enclosure Page 6 of 6
- 4.
Letter from the U.S. NRC to the Energy Harbor Nuclear Corp., "Perry Nuclear Power Plant, Unit No. 1 - Issuance of Amendment No. 197 Regarding the Adoption of TSTF-566, Revision 0, 'Revise Actions for Inoperable RHR Shutdown Cooling Subsystem,' and TSTF-580, Revision 1, 'Provide Exception from Entering Mode 4 With No Operable RHR Shutdown Cooling,' (EPID L-2020-LLA-0281)," dated January 10, 2022 (ADAMS Accession Number ML21322A260)
ENCLOSURE ATTACHMENT 1 MONTICELLO NUCLEAR GENERATING PLANT APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT TSTF-566, "REVISE ACTIONS FOR INOPERABLE RHR SHUTDOWN COOLING SUBSYSTEMS,"
AND TSTF 580, REVISION 1, "PROVIDE EXCEPTION FROM ENTERING MODE 4 WITH NO OPERABLE RHR SHUTDOWN COOLING," USING THE CONSOLIDATED LINE-ITEM IMPROVEMENT PROCESS TECHNICAL SPECIFICATION PAGES (MARKUP)
(7 Pages Follow)
RHR Shutdown Cooling System - Hot Shutdown 3.4.7 Monticello 3.4.7-1 Amendment No. 146 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.7 Residual Heat Removal (RHR) Shutdown Cooling System - Hot Shutdown LCO 3.4.7 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.
NOTES-------------------------------------------
1.
Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
2.
One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of Surveillances.
APPLICABILITY:
MODE 3 with reactor steam dome pressure less than the RHR shutdown cooling supply isolation interlock.
ACTIONS
NOTE-----------------------------------------------------------
Separate Condition entry is allowed for each RHR shutdown cooling subsystem.
CONDITION REQUIRED ACTION COMPLETION TIME A. One or two RHR shutdown cooling subsystems inoperable.
A.1 Initiate action to restore RHR shutdown cooling subsystem(s) to OPERABLE status.
AND A.2 Verify an alternate method of decay heat removal is available for each inoperable RHR shutdown cooling subsystem.
AND A.3 Be in MODE 4.
Immediately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 24 hours AND Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter A.1 Place Specification 3.4.7 - Insert A after Condition A Here required TBD
Specification 3.4.7 - Insert A ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B.
Required Action and associated Completion Time of Condition A not met.
B.1 Initiate action to restore RHR shutdown cooling subsystem to OPERABLE status.
Immediately C.
Two required RHR shutdown cooling subsystems inoperable.
C.1 Verify an alternate method of decay heat removal is available for each inoperable RHR shutdown cooling subsystem.
1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> AND Once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter D.
Required Action and associated Completion Time of Condition C not met.
NOTE-----------------
LCO 3.0.3 and all other LCO Required Actions requiring a MODE change to MODE 4 may be suspended until one RHR shutdown cooling subsystem is restored to OPERABLE status.
Immediately D.1 Initiate action to restore one RHR shutdown cooling subsystem to OPERABLE status.
Will be new page 3.4.7-2.
RHR Shutdown Cooling System - Hot Shutdown 3.4.7 Monticello 3.4.7-2 Amendment No. 200 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. No RHR shutdown cooling subsystem in operation.
AND No recirculation pump in operation.
B.1 Initiate action to restore one RHR shutdown cooling subsystem or one recirculation pump to operation.
AND B.2 Verify reactor coolant circulation by an alternate method.
AND B.3 Monitor reactor coolant temperature and pressure.
Immediately 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from discovery of no 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 Once per hour SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.7.1
NOTE-------------------------------
Not required to be met until 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after reactor steam dome pressure is less than the RHR shutdown cooling supply isolation interlock.
Verify one RHR shutdown cooling subsystem or recirculation pump is operating.
In accordance with the Surveillance Frequency Control Program E.1 E.2 E.3 E.
TBD 3
RHR Shutdown Cooling System - Hot Shutdown 3.4.7 Monticello 3.4.7-3 Amendment No. 200 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.4.7.2
NOTE-------------------------------
Not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after reactor steam dome pressure is less than the RHR shutdown cooling supply isolation interlock.
Verify RHR shutdown cooling subsystem locations susceptible to gas accumulation are sufficiently filled with water.
In accordance with the Surveillance Frequency Control Program TBD 4
RHR Shutdown Cooling System - Cold Shutdown 3.4.8 Monticello 3.4.8-1 Amendment No. 146 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.8 Residual Heat Removal (RHR) Shutdown Cooling System - Cold Shutdown LCO 3.4.8 Two RHR shutdown cooling subsystems shall be OPERABLE, and, with no recirculation pump in operation, at least one RHR shutdown cooling subsystem shall be in operation.
NOTES-------------------------------------------
1.
Both RHR shutdown cooling subsystems and recirculation pumps may be removed from operation for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period.
2.
One RHR shutdown cooling subsystem may be inoperable for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for the performance of Surveillances.
APPLICABILITY:
MODE 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 cooling subsystems inoperable.
A.1 Verify an alternate method of decay heat removal is available for each inoperable RHR shutdown cooling subsystem.
1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 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. No RHR shutdown cooling subsystem in operation.
AND No recirculation pump in operation.
B.1 Verify reactor coolant circulating by an alternate method.
AND 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> from discovery of no 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 TBD C.1 C.
Place Specification 3.4.8 - Insert A Here
Specification 3.4.8 - Insert A B.
Required Action and associated Completion Time of Condition A not met.
B.1 Initiate action to restore RHR shutdown cooling subsystem(s) to OPERABLE status.
Immediately
RHR Shutdown Cooling System - Cold Shutdown 3.4.8 Monticello 3.4.8-2 Amendment No. 200 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B.2 Monitor reactor coolant temperature and pressure.
Once per hour SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.8.1 Verify one RHR shutdown cooling subsystem or recirculation pump is operating.
In accordance with the Surveillance Frequency Control Program SR 3.4.8.2 Verify RHR shutdown cooling subsystem locations susceptible to gas accumulation are sufficiently filled with water.
In accordance with the Surveillance Frequency Control Program TBD C.2
RHR Shutdown Cooling System - Hot Shutdown B 3.4.7 Monticello B 3.4.7-3 Revision No. 52 BASES ACTIONS A Note has been provided to modify the ACTIONS related to RHR shutdown cooling subsystems. Section 1.3, Completion Times, specifies once a Condition has been entered, subsequent divisions, subsystems, components or variables expressed in the Condition, discovered to be inoperable or not within limits, will not result in separate entry into the Condition. Section 1.3 also specifies Required Actions of the Condition continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for inoperable shutdown cooling subsystems provide appropriate compensatory measures for separate inoperable shutdown cooling subsystems. As such, a Note has been provided that allows separate Condition entry for each inoperable RHR shutdown cooling subsystem.
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. 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.
The required cooling capacity of the alternate method should be 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 Condensate/Feed and Main Steam Systems and the Reactor Water Cleanup System.
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.
sufficient B.1 If the required alternate method of decay heat removal cannot be verified within one hour, immediate action must be taken to restore the inoperable RHR shutdown cooling subsystem 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.
, or an inoperable but functional RHR shutdown cooling subsystem.
RHR Shutdown Cooling System - Hot Shutdown B 3.4.7 Monticello B 3.4.7-4 Revision No. 52 BASES ACTIONS (continued)
B.1, B.2, and B.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.
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.
E.1, E.2, and E.3 Place Bases Specification 3.4.7 - Insert A after new Condition B Here functional availability TBD
Bases Specification 3.4.7 - Insert A C.1 With both required RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability. This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore, verification of the functional availability of these alternate method(s) must be reconfirmed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> thereafter. This will provide assurance of continued heat removal capability.
The required cooling capacity of the alternate method should be sufficient to maintain or reduce temperature. Decay heat removal by ambient losses can be considered as, or contributing to, the alternate method capability. Alternate methods that can be used include (but are not limited to) the Condensate/Feed and Main Steam Systems, 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 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.
RHR Shutdown Cooling System - Cold Shutdown B 3.4.8 Monticello B 3.4.8-3 Revision No. 52 BASES ACTIONS A Note has been provided to modify the ACTIONS related to RHR shutdown cooling subsystems. Section 1.3, Completion Times, specifies once a Condition has been entered, subsequent divisions, subsystems, components or variables expressed in the Condition, discovered to be inoperable or not within limits, will not result in separate entry into the Condition. Section 1.3 also specifies Required Actions of the Condition continue to apply for each additional failure, with Completion Times based on initial entry into the Condition. However, the Required Actions for inoperable shutdown cooling subsystems provide appropriate compensatory measures for separate inoperable shutdown cooling subsystems. As such, a Note has been provided that allows separate Condition entry for each inoperable RHR shutdown cooling subsystem.
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 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 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 Reactor Water Cleanup System by itself or using feed and bleed in combination with Control Rod Drive System or Condensate/Feed Systems.
B.1 and B.2 With no RHR shutdown cooling subsystem and no recirculation pump in operation, except as 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 /> sufficient or an inoperable but functional RHR shutdown cooling subsystem.
C.1 and C.2 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 - High Water Level B 3.9.7 Monticello B 3.9.7-2 Revision No. 52 BASES LCO (continued) 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 for the operating subsystem to be removed from operation 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 and in operation in MODE 5, with irradiated fuel in the RPV and with the water level 21 feet 11 inches above the top of the RPV flange, to provide decay heat removal. RHR shutdown cooling subsystem requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS). RHR shutdown cooling subsystem requirements in MODE 5 with irradiated fuel in the reactor pressure vessel and with the water level < 21 ft 11 inches above the RPV flange are given in LCO 3.9.8, "Residual Heat Removal (RHR) - Low Water Level."
ACTIONS A.1 With the required RHR shutdown cooling subsystem inoperable, an alternate method of decay heat removal must be provided 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 decay heat removal function and the probability of a loss of the available decay heat removal capabilities.
Furthermore, verification of the functional availability of the alternate method 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 operating procedures. The required cooling capability of the alternate method should be ensured by verification (by calculation or demonstration) of its capability to maintain or reduce temperature. For example, this may include the use of the Fuel Pool Cooling System or the Reactor Water Cleanup System operating with the regenerative heat exchanger bypassed (heat reject mode).
Either or both systems may be used to reject hot water while using a cooler source of water for makeup. The method used to remove the decay heat should be the most prudent choice based on unit conditions.
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) sufficient or an inoperable but functional RHR shutdown cooling subsystem.
RHR - Low Water Level B 3.9.8 Monticello B 3.9.8-2 Revision No. 52 BASES ACTIONS (continued) 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 for the operating subsystem to be removed from operation 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, and one must be in operation in MODE 5, with irradiated fuel in the RPV and with the water level < 21 ft 11 inches above the top of the RPV flange, to provide decay heat removal. RHR shutdown cooling subsystem requirements in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS). RHR shutdown cooling subsystem requirements in MODE 5 with irradiated fuel in the RPV and with the water level 21 ft 11 inches above the RPV flange are given in LCO 3.9.7, "Residual Heat Removal (RHR) - High Water Level."
ACTIONS 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 reliability is reduced.
Therefore, an alternate method of decay heat removal must be provided.
With both required RHR shutdown cooling subsystems inoperable, an alternate method of decay heat removal must be provided in addition to that provided for the initial RHR shutdown cooling subsystem inoperability. This re-establishes backup decay heat removal capabilities, similar to the requirements of the LCO. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is based on the decay heat removal function and the probability of a loss of the available decay heat removal capabilities. Furthermore, verification of the functional availability of this 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 operating procedures. The required cooling capacity of the alternate method should be ensured by verification (by calculation or demonstration) of its capability to maintain or reduce temperature. For example, this may include the use of the Fuel Pool Cooling System or the Reactor Water Cleanup System operating with the regenerative heat exchanger bypassed (heat reject mode). Either or both systems may be used to reject hot water while using a cooler source of water for makeup. The method used to remove decay heat should be the most prudent choice based on unit conditions.
sufficient 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)
, or an inoperable but functional RHR shutdown cooling subsystem. These TBD