ML16034A032: Difference between revisions

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{{Adams
#REDIRECT [[AEP-NRC-2016-07, License Amendment Request to Revise Technical Specifications to Adopt Technical Specifications Task Force-523, Generic Letter 2008-01, Managing Gas Accumulation.]]
| number = ML16034A032
| issue date = 01/29/2016
| title = License Amendment Request to Revise Technical Specifications to Adopt Technical Specifications Task Force-523, Generic Letter 2008-01, Managing Gas Accumulation.
| author name = Lies Q S
| author affiliation = Indiana Michigan Power Co
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000315, 05000316
| license number =
| contact person =
| case reference number = AEP-NRC-2016-07, GL-2008-01
| document type = Letter, License-Application for Facility Operating License (Amend/Renewal) DKT 50, Technical Specification, Bases Change
| page count = 83
| project =
| stage = Other
}}
 
=Text=
{{#Wiki_filter:zNIN nin Mcia oe MINHIANA Coiak Michlgan Power MICHIGANn CookNula Plant A unt o Amricn Elctrc PwerBridgrnan, Ml 49106 A unt o~meica Eletri PoerIndtanaMichigan Power~corn January 29, 2016 AEP-NRC-201 6-07 10 CFR 50.90 Docket Nos. 50-315 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk ..Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 1 and Unit 2 License Amendment Request to Revise Technical Specifications to Adopt Technical Specifications Task Force-523, "Generic Letter 2008-01, Managing Gas Accumulation," Using the Consolidated Line Item Improvement Process
 
==References:==
: 1. Technical Specifications Task Force (TSTF)-523, "Generic Letter 2008-01, Managing Gas Accumulation," Revision 2, dated February 21, 2013, Agencywide Documents Access and Management System (ADAMS) Accession No. ML13053A075.
: 2. Notice of Availability of the "TSTF-523, 'Generic Letter 2008-01, Managing Gas Accumulation,'
Using the Consolidated Line Item Improvement Process," dated December 23, 2013, ADAMS ACcession No. ML13255A167.
: 3. Letter from J. P. Gebbie, Indiana Michigan Power Company (I&M), to Nuclear Regulatory Commission (NRC),. "Donald C. Cook Nuclear Plant Units 1 and 2 'Evaluation of TSTF-523,"Generic Letter 2008-01, Managing Gas Accumulation" dated March 7, 2014, ADAMS Accession No. ML14070A344.
: 4. Letter from J. P. Gebbie, I&M, to NRC, "Donald C. Cook Nuclear Plant Unit 1 and Unit 2-Commitment Schedule Change Related to Technical Specification Task Force-523," dated June 24, 2015, ADAMS Accession No. ML15181A256.
In accordance with the provisions of Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), Indiana Michigan Power Company (I&M) is submitting a request for an amendment to the Technical Specifications (TS) for Donald C. Cook Nuclear Plant, Units 1 and 2. ..The proposed amendment would modify TS requirements to address Generic Letter 2008-01,"Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (GL 2008-01), as described in Technical Specifications Task Force (TSTF)-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation" (Reference 1). A Notice of Availability of TSTF-523 was published on December 23, 2013 (Reference 2).
U. S. Nuclear Regulatory Commission AEP-NRC-201 6-07 Page 2 l&M-committed in Reference 3 to conduct additional evaluation of the issues described in GL 2008-01, and to submit a license amendment request (LAR) based on the evaluation following Nuclear Regulatory Commission (NRC) approval of TSTF-523 (Reference 2). In Reference 4, I&M provided information regarding the evaluation and revised the commitment date for submitting the LAR. The evaluation to review affected systems and identify locations susceptible to gas accumulation has been completed.
This submittal satisfies the commitment to submit an [AR.Enclosure 1 to this letter provides an affirmation statement.
Enclosure 2 provides a description and assessment of the proposed change. Enclosures 3 and 4 provide existing Unit 1 and Unit 2 TS pages, respectively, marked up to show the proposed changes. Enclosures 5 and 6 provide existing Unit 1 and Unit 2 TS Bases pages, respectively, marked up to show the proposed changes.TS Bases markups are included for information only. Changes to the existing TS Bases, consistent with the technical and regulatory analyses, will be implemented under the TS Bases Control Program. New clean Unit 1 and Unit 2 TS pages, with proposed changes incorporated will be provided to the NRC Licensing Project Manager (PM) when requested.
Approval of the proposed amendment is requested in accordance with the normal NRC review schedule for such changes. Once approved, the amendment will be implemented within 180 days.I&M recently submitted an [AR to implement a TS surveillance frequency control program, which has not yet been approved by the NRC. The coordination of that [AR with the amendment request in this letter, and the potential to supplement or revise this request following approval of that [AR, have been discussed with the NRC PM. Copies of this letter are being transmitted to the Michigan Public Service Commission and Michigan Department of Environmental Quality, in accordance with the requirements of 10 CFR 50.91.There are no new regulatory commitments made in this letter. Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649.Sincerely, Q. Lies Site Vice President TLC/mll
 
==Enclosures:==
: 1. Affirmation
: 2. Evaluation of the Proposed License Amendment 3. Donald C. Cook Nuclear Plant Unit 1. Technical Specification Pages Marked To Show Proposed Changes 4. Donald C. Cook Nuclear Plant Unit 2 Technical Specification Pages Marked To Show Proposed Changes U. S. Nuclear Regulatory Commission Page 3 AEP-NRC-201 6-07 5. Donald C. Cook Nuclear Plant Unit 1 Technical Specification Bases Pages Marked To Show Proposed Changes (For Information Only)6. Donald C. Cook Nuclear Plant Unit 2 Technical Specification Bases Pages Marked To.Show Proposed Changes (For Information Only)c: R. J. Ancona, MPSC A. W. Dietrich, NRC, Washington, D.C.MDEQ -RMD/RPS NRC .Resident Inspector C. D. Pederson, NRC, Region Ill A. J.-Williamson, AEP Ft. Wayne, w/o enclosures Enclosure 1Ito AEP-NRC-2016-07 AFFIRMATION I, Q. Shane Lies, being duly sworn, state that I am the Site Vice President of Indiana Michigan Power Company (I&M), that I am authorized to sign and file this request with the U. S. Nuclear Regulatory Commission on behalf of l&M, and that the statements made and the matters set forth herein pertaining to I&M are true and correct to the best of my knowledge, information, and belief.Indiana Michigan Power Company Q. Shane Lies Site Vice President SWORN TO AND SUBSCRIBED BEFORE ME THIS DAY OF
,4 2016 My Commission Expires -o.tZ_DANIELLE BUJRGOYNE Notary Public, State of Michigan My Co unty' of Berrien My Commission Expires 0 421 A ctingln the County of 4Sy01 Enclosure 2 to AEP-NRC-2016-07 Evaluation of the Proposed License Amendment
 
==1.0 DESCRIPTION==
 
The proposed change revises or adds Surveillance Requirements (SRs) to verify that the system locations susceptible to gas accumulation are sufficiently filled with water and to provide allowances, which permit performance of the verification.
The changes are being made to address the concerns discussed in Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems." The proposed amendment is consistent with Technical Specification Task Force (TSTF)Traveler-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation." 2.0 ASSESSMENT
 
===2.1 Applicability===
 
of Published Safety Evaluation Indiana Michigan Power Company (I&M) has reviewed the model safety evaluation dated December 23, 2013, Agency~wide Documents Access and Management Systems, Accession No. ML1 3255A1 69 as part of the Federal Register Notice of Availability.
This review included a review of the Nuclear Regulatory Commission (NRC) staff's evaluation, as well as the information provided in TSTF-523.
As described in the subsequent paragraphs, I&M has concluded that the justifications presented in the TSTF-523 proposal and the model safety evaluation prepared by the NRC staff are applicable to Donald C. Cook Nuclear Plant (CNP), Units 1 and 2, and justify this amendment for the incorporation of the changes to the CNP Technical Specifications (TS).The TSTF Traveler and model Safety Evaluation discuss the applicable regulatory requirements and guidance, including the Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR 50), Appendix A, General Design Criteria (GDC). CNP was not licensed to 10 CFR 50, Appendix A, GDC. Conformance to the applicable GDC is discussed in Section 1.4 of the CNP Updated Final Safety Analysis Report. This difference does not alter the conclusion that the proposed change is applicable to CNP.2.2 Optional Chancies and Variations l&M is proposing the following variations from the TS changes described in TSTF-523, Revision 2, or the applicable parts of the NRC staff's model safety evaluation dated December 23, 2013. _The CNP TS do not have the existing SR revised by TSTF-523 and some sections utilize different numbering than the Standard Technical Specifications (STS) for Westinghouse Plants (NUREG-1431), on which TSTF-523 was based. Implementation of TSTF-523 will add a new SR to TS 3.5.2, [Emergency Core Cooling System] "ECCS -Operating." Specifically, Westinghouse STS SR 3.5.2.3 was not used when I&M converted to STS. For CNP TS 3.5.2, SR 3.5.2.3 from TSTF-523 will be inserted after CNP TS SR 3.5.2.7 as new SR 3.5.2.8, so the numbering of the existing SRs will not change.
Enclosure 2 to AEP-NRC-2016-07 Pg Page 2 Additionally, because of the insertion of TS SR 3.5.2.8, CNP TS SR 3.5.3.1 is being revised with updated numbering from TS 3.5.2. Finally, TSTF-523 TS 3.9.5, [Residual Heat Removal] "RHR and Coolant Circulation
-High Water Level," and 3.9.6, "RHR and Coolant Circulation
-Low Water Level," are numbered 3.9.4 and 3.9.5, respectively, in the CNP TS.These differences are administrative and do not affect the applicability of TSTF-523 to the CNP TS.3.0 REGULATORY ANALYSIS 3.1 No Siqnificant Hazards Consideration Determination I&M requests adoption of TSTF-523, Revision 1, "Generic Letter 2008-01, Managing Gas Accumulation," which is an approved change to the STS, into the CNP Unit 1 and Unit 2 TS.The proposed change revises or adds SRs to verify that the system locations susceptible to gas accumulation are sufficiently filled with water and to provide allowances, which permit performance of the verification.
I&M has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50:92, "Issuance of amendment," as discussed below: 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response:
No.SThe proposed change revises or adds SRs that require verification that the ECCS, RHR System, and the Containment Spray (CTS) System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification.
Gas accumulation in the subject systems is not an initiator of any accident previously evaluated.
As a result, the' probability of any accident previously evaluated is not significantly increased.
The proposed SRs ensure that the subject systems continue to be capable to perform their assumed safety function and are not rendered inoperable due to gas accumulation.
Thus, the consequences of any accident previously evaluated are not significantly increased.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
: 2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Response:
No.The proposed change revises or adds SRs that require verification that the ECCS, the RHR System, and the CTS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification.
The proposed change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation.
In addition, the Enclosure 2 to AEP-NRC-2016-07 Pg Page 3 proposed change does not impose any new or different requirements that could initiate an accident.
The proposed change does not alter assumptions made in the safety analysis and is consistent with the safety analysis assumptions.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
: 3. Does the proposed change involve a significant reduction in a margin of safety?Response:
No.The proposed change revises or adds SRs that require verification that the ECCS, the RHR System, and the CTS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification.
The proposed change adds new requirements to manage gas accumulation in order to ensure the subject systems are capable of performing their assumed safety functions.
The proposed SRs are more comprehensive than the current SRs and will ensure that the assumptions of the safety analysis are protected.
The proposed change does not adversely affect any current plant safety margins or the reliability of the equipment assumed in the safety analysis.
Therefore, there are no changes being made to any safety analysis assumptions, safety limits or limiting safety system settings that would adversely affect plant safety as a result of the proposed change.Therefore, the proposed change does not involve a significant reduction in a margin of safety.Based on the above, I&M concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of "no significant hazards consideration" is justified.
 
===4.0 ENVIRONMENTAL===
 
EVALUATION The proposed change 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 SR. However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure..
Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Therefore, pursuant to 10 CFR 51 .22Cb)_,.
no _environmental impact statement or environmental assessment need be prepared in connection with the proposed change.
Enclosure 3 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 1 TECHNICAL SPECIFICATION PAGES MARKED TO SHOW PROPOSED CHANGES RCS Loops -MODE 4 3.4.6 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. Two required loops B.1 Suspend operations that Immediately inoperable, would cause introduction of coolant into the RCS with OR boron concentration less than required to meet the Required loop not in requirements of LCO 3.1.1.operation.
AND B.2 Initiate action to restore one Immediately loop to OPERABLE status and operation.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.6.1 Verify required RHR or RCS loop is in operation.
12 hours SR 3.4.6.2 Verify SG secondary side water levels are above the 12 hours lower tap of the SG wide range level instrumentation by > 420 inches for required RCS loops.SR 3.4.6.3---------------------NOTE---------------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required pump.SR 3.4.6.4 -- --NOTE----------------.......
Not required to be performed until 12 hours after enteringq Mode 4.Verify required RHR loop locations susceptible to 31 days ,qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1346-AmnetNo28 3.4.6-2 Amendment No. 287 RCS Loops -MODE 5, Loops Filled 3.4.7 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.7.1 Verify required RHR loop is in operation.
12 hours SR 3.4.7.2 Verify SG secondary side water level is above the 12 hours lower tap of the SG wide range level instrumentation by > 420 inches in required SGs.SR 3.4.7.3------------NOTE----...................
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.7.4 Verify required RHR loop locations susceptible to 31 days.gas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1347-AmnetNo28 3.4.7-3 Amendment No. 287 RCS Loops -MODE 5, Loops Not Filled 3.4.8 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. No required RHR loop 8.1 Suspend operations that Immediately OPERABLE.
would cause introduction of coolant into the RCS with OR boron concentration less i than required to meet Required RHR loop not requirements of LCO 3.1 .1.in operation.
AND 8.2 Initiate action to restore one Immediately RHR loop to OPERABLE status and operation.
SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.4.8.1 Verify required RHR loop is in operation.
12 hours SR 3.4.8.2 ...........
NOTE............--OT Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.8.3 Verify RHR loop locations susceptible to ,qas accumulation are sufficiently filled with water.31 days Cook Nuclear Plant Unit 13482AmnetNo27 3.4.8-2 Amendment No. 287 ECCS -Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify the following valves are in the listed position with power to the valve operator removed.12 hours Number 1 -1MO-261 1 -1MO-262 1 -1MO-263 1-1MO-315 1 -1MO-325 1-I1MO-390 1 -ICM-305 1 -ICM-306 Position Open Open Open Closed Closed Open Closed Closed Function SI suction line Mini flow line Mini flow line Low head SI to hot leg Low head SI to hot leg RWST to RHR Sump line Sump line SR 3.5.2.2 ...........
...... .NOTE -........
...........
31 days Not required to be met for system vent flow paths opened under administrative control.____________Verify each ECCS manual, power operated, and automatic valve in the flow path, that is not locked, sealed, or otherwise secured in position, is in the correct position.SR 3.5.2.3 Verify each ECCS pump's developed head at the In accordance test flow point is greater than or equal to the with the Inservice required developed head. Testing Program SR 3.5.2.4 Verify each ECCS automatic valve in the flow path 24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.5.2.5 Verify each ECCS pump starts automatically on an 24 months actual or simulated actuation signal.Cook Nuclear Plant Unit 1352-AmnetNo28 3.5.2-2 Amendment No. 287 ECCS -Operating 3.5.2 SURVEILLANCE REQUI REMENTS ('continued)
SURVEILLANCE FREQUENCY SR 3.5.2.6 Verify, for each ECCS throttle valve listed below, each position stop is in the correct position.24 months Valve Number 1-SI-121 N 1-S1-121 S 1-S1-141 Li 1-S1-141 L2 1-S1-141 L3 1-S1-141 L4 SR 3.5.2.7 Verify, by visual inspection, each ECCS train 24 months containment sump suction inlet is not restricted by debris and the suction inlet strainers show no evidence of structural distress or abnormal corrosion.
SR 3.5.2.8 Verify ECCS locations susceotible to aas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1 3523AedetN.2~
9 3.5.2-3 Amendment No. 287, 299 ECCS -Shutdown 3.5.3 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.3.1--------------
NOTE- -------For SR 3.5.2.2, the SR is modified to allow the valves to not be in the correct position, provided they can be aligned to the correct position.The following SRs are applicable for all equipment required to be OPERABLE: In accordance with applicable SRs SR 3.5.2.2, SR 3.5.2.3, SR 3.5.2.6, ai~d SR 3.5.2.7, and SR 3.5.2.8 Cook Nuclear Plant Unit 1 ..- mnmn o 8 3.5.3-2 Amendment No. 287 Containment Spray System 3.6.6 3.6 CONTAINMENT SYSTEMS 3.6.6 Containment Spray System LCO 3.6.6 APPLICABILITY:
Two containment spray trains shall be OPERABLE.MODES 1, 2, 3, and 4.ACTIONS_____
___CONDITION REQUIRED ACTION COMPLETION TIME A. One containment spray A.1 Restore containment spray 72 hours train inoperable, train to OPERABLE status.B. Required Action and B.1 Be in MODE 3. 6 hours associated Completion Time not met. AND B.2 Be in MODE 5. 84 hours SURVEILLANCE REQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.6.6.1------------NOTE----------31 days Not required to be met for system vent flow paths opened under administrative control._____________Verify each containment spray manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.Cook Nuclear Plant Unit 1 ..- mnmn o 8 3.6.6-1 Amendment No. 287 Containment Spray System 3.6.6 SURVEILLANCE REQUI REMENTS (continued)________
SURVEILLANCE FREQUENCY SR 3.6.6.2 Verify each containment spray pump's developed In accordance head at the flow test point is greater than or equal to with the Inservice the required developed head. Testing Program SR 3.6.6.3---------------------NOTE--------------
In MODE 4, only the manual portion of the actuation signal is required.Verify each automatic containment spray valve in 24 months the flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.6.6.4 ...............---..
NOTE----------------.......
In MODE 4, only the manual portion of the actuation signal is required.Verify each containment spray pump starts 24 months automatically on an actual or simulated actuation signal.SR 3.6.6.5 Verify each spray nozzle is unobstructed.
Following maintenance that could result in nozzle blockage SR 3.6.6.6 Verify containment spray locations susceptible to 31 days gas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1 3.6.6-2 CookNucearPlat Unt 13.66-2Amendment No. 28-7, 314 RHR and Coolant Circulation
-High Water Level 3.9.4 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME A.4 Close equipment hatch and 4 hours secure with four bolts.AND A.5 Close one door in each air 4 hours lock.AND A.6 Verify each penetration 4 hours providing direct access from the containment atmosphere to the outside atmosphere is either closed with a manual or automatic isolation valve, blind flange, or equivalent, or is capable of being closed by an OPERABLE Containment Purge Supply and Exhaust System.SURVEILLANCE REQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.9.4.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.4.2 Verify required RHR loop locations susceptible to 31 days.qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1 ..- mnmn o 8 3.9.4-2 Amendment No. 287 RHR and Coolant Circulation
-Low Water Level 3.9.5 SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.9.5.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.5.2------------NOTE-
-------Not required to be performed until 24 hours after a required RHR pump is not in operation.
Verify correct breaker alignment and indicated 7 days power available to the required RHR pump that is not in operation.
SR 3.9.5.3 Verify RHR loop locations susceptible to ,qas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1395-AmnetNo28 3.9.5-3 Amendment No. 287 Enclosure 4 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 2 TECHNICAL SPECIFICATION PAGES MARKED TO SHOW PROPOSED CHANGES RCS Loops -MODE 4 3.4.6 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. Two required loops B.1 Suspend operations that Immediately inoperable, would cause introduction of coolant into the RCS with OR boron concentration less than required to meet the Required loop not in requirements of LCO 3.1.1.operation.
AND B.2 Initiate action to restore one Immediately loop to OPERABLE status and operation.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.6.1 Verify required RHR or RCS loop is in operation.
12 hours SR 3.4.6.2 Verify SG secondary side water levels are above the 12 hours lower tap of the SG wide range level instrumentation by > 418.77 inches for required RCS loops.SR 3.4.6.3 ----NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required pump.SR 3.4.6.4 NOTE..............
....NOT Not required to be performed until 12 hours after enteringq Mode 4.Verify required RHR loop locations susceptible to 31 days ,qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 23462AmnetNo29 3.4.6-2 Amendment No. 269 RCS Loops -MODE 5, Loops Filled 3.4.7 SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.4.7.1 Verify required RHR loop is in operation.
12 hours SR 3.4.7.2 Verify SG secondary side water level is above the 12 hours lower tap of the SG wide range level instrumentation by > 418.77 inches in required SGs.SR 3.4.7.3------------NOTE--...............
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.7.4 Verify required RHR loop locations susceptible to 31 days.qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 234.3AmnetNo26 3.4.7-3 Amendment No. 269 RCS Loops -MODE 5, Loops Not Filled 3.4.8 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. No required RHR loop B.1 Suspend operations that Immediately OPERABLE.
would cause introduction of coolant into the RCS with OR boron concentration less than required to meet Required RHR loop not requirements of LCO 3.1.1.in operation.
AND B.2 Initiate action to restore one Immediately RHR loop to OPERABLE status and operation.
SURVEILLANCE REQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.4.8.1 Verify required RHR loop is in operation.
12 hours SR 3.4.8.2-------------NOTE-
--- --Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.8.3 Verify RHR loop locations susceptible to ,qas accumulation are sufficiently filled with water.31 days Cook Nuclear Plant Unit 23482AmnetNo26 3.4.8-2 Amendment No. 269 ECCS -Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify the following valves are in the listed position with power to the valve operator removed.12 hours Number 2-1MO-261 2-I1MO-262 2-1MO-263 2-I1MO-31 5 2-I1MO-325 2-I1MO-390 2-1CM-305 2-1CM-306 Position Open Open Open Closed Closed Open Closed Closed Function SI suction line Mini flow line Mini flow line Low head SI to hot leg Low head SI to hot leg RWST to RHR Sump line Sump line SR 3.5.2.2-----------------..........NOTE----------31 days Not required to be met for system vent flow paths opened under administrative control.____________Verify each ECCS manual, power operated, and automatic valve in the flow path, that is not locked, sealed, or otherwise secured in position, is in the correct position.SR 3.5.2.3 Verify each ECCS pump's developed head at the In accordance test flow point is greater than or equal to the with the Inservice required developed head. Testing Program SR 3.5.2.4 Verify each ECCS automatic valve in the flow path 24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.5.2.5 Verify each EGGS pump starts automatically on an 24 months actual or simulated actuation signal.Cook Nuclear Plant Unit 2352-AmnetNo26 3.5.2-2 Amendment No. 269 ECCS -Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.5.2.6 Verify, for each ECCS throttle valve listed below, each position stop is in the correct position.24 months Valve Number 2-S1-121 N 2-S1-121 S 2-S1-141 Li 2-S1-141 L2 2-S1-141 L3 2-S1-141 L4 SR 3.5.2.7 Verify, by visual inspection, each ECCS train 24 months containment sump suction inlet is not restricted by debris and the suction inlet trash racks and screens show no evidence of structural distress or abnormal corrosion.
SR 3.5.2.8 Verify ECCS locations susceptible to .gas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2 3523AedetN.2Q 8 3.5.2-3 Amendment No. 269, 282 ECCS -Shutdown 3.5.3 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY-I-SR 3.5.3.1---------------
NOTE----------..-
For SR 3.5.2.2, the SR is modified to allow the valves to not be in the correct position, provided they can be aligned to the correct position.The following SRs are applicable for all equipment required to be OPERABLE: In accordance with applicable SRs SR 3.5.2.2, SR 3.5.2.3, SR 3.5.2.6, a~SR 3.5.2.7, and SR 3.5.2.8 Cook Nuclear Plant Unit 23532AmnetNo26 3.5.3-2 Amendment No. 269 Containment Spray System 3.6.6 3.6 CONTAINMENT SYSTEMS 3.6.6 Containment Spray System LCO 3.6.6 APPLICABILITY:
Two containment spray trains shall be OPERABLE.MODES 1, 2, 3, and 4.ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One containment spray A.1 Restore containment spray 72 hours train inoperable, train to OPERABLE status.B. Required Action and B.1 Be in MODE 3. 6 hours associated Completion Time not met. AND B.2 Be in MODE 5. 84 hours SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.6.6.1---------- -NOTE-------
-31 days Not required to be met for system vent flow paths opened under administrative control._____________Verify each containment spray manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.Cook Nuclear Plant Unit 236.-AmnetNo29 3.6.6-1 Amendment No. 269 Containment Spray System 3.6.6 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.6.6.2 Verify each containment spray pump's developed In accordance head at the flow test point is greater than or equal to with the Inservice the required developed head. Testing Program SR 3.6.6.3--------------------NOTE------------
In MODE 4, only the manual portion of the actuation signal is required.Verify each automatic containment spray valve in 24 months the flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.6.6.4---------------------NOTE--------------
In MODE 4, only the manual portion of the actuation signal is required.Verify each containment spray pump starts 24 months automatically on an actual or simulated actuation signal.SR 3.6.6.5 Verify each spray nozzle is unobstructed.
Following maintenance that could result in nozzle blockage SR 3.6.6.6 Verify containment spray locations susceptible to 31 days.qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2 3662AedetN.29 9 3.6.6-2 Amendment No. 2-69, 298 RHR and Coolant Circulation
-High Water Level 3.9.4 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME A.4 Close equipment hatch and 4 hours secure with four bolts.AND A.5 Close one door in each air 4 hours lock.AND A.6 Verify each penetration 4 hours providing direct access from the containment atmosphere to the outside atmosphere is either closed with a manual or automatic isolation valve, blind flange, or equivalent, or is capable of being closed by an OPERABLE Containment Purge Supply and Exhaust System.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.9.4.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.4.2 Verify required RHR loop locations susceptible to 31 days ,qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2394-AmnetNo26 3.9.4-2 Amendment No. 269 RHR and Coolant Circulation
-Low Water Level 3.9.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.9.5.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.5.2---------
-NOTE-- -----Not required to be performed until 24 hours after a required RHR pump is not in operation.
Verify correct breaker alignment and indicated 7 days power available to the required RHR pump that is not in operation.
SR 3.9.5.3 Verify RHR loop locations susceptible to ,qas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2395-AmnetNo26 3.9.5-3 Amendment No. 269 Enclosure 5 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 1 TECHNICAL SPECIFICATION BASES PAGES MARKED TO SHOW PROPOSED CHANGES (FOR INFORMATION ONLY)
RCS Loops -MODE 4 B 3.4.6 BASES LCO (continued)
Utilization of the Note is permitted provided the following conditions are met: a. No operations are permitted that would dilute the RCS boron concentration with coolant with boron concentrations less than required to meet the requirements of LCO 3.1 .1, "SHUTDOWN MARGIN (SDM)," therefore maintaining the margin to criticality.
Boron reduction with coolant at boron concentrations less than required to assure SDM is maintained is prohibited because a uniform concentration distribution throughout the RCS cannot be ensured when in natural circulation; and b. Core outlet temperature is maintained at least 1 0°F below saturation temperature, so that no vapor bubble may form and possibly cause a natural circulation flow obstruction.
Note 2 requires that the secondary side water temperature of each SG be< 50&deg;F above each of the RCS cold leg temperatures or the pressurizer water level be < 62% before the start of an RCP with any RCS cold leg temperature
< 152&deg;F. This restraint is to prevent a low temperature overpressure event due to a thermal transient when an RCP is started.An OPERABLE RCS loop comprises an OPERABLE RCP and an OPERABLE SG, which has the minimum water level specified in SR 3.4.6.2.Similarly for the RHR System, an OPERABLE RHR loop comprises an OPERABLE RHR pump (either the east or west) capable of providing forced flow to an OPERABLE RHR heat exchanger.
RCPs and RHR pumps are OPERABLE if they are capable of being powered and are able to provide forced flow if required.
Management of gas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 4, this LCO ensures forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing.One loop of either RCS or RHR provides sufficient circulation for these purposes.
However, two loops consisting of any combination of RCS and RHR loop~s are required to be OPERABLE to meet single failure considerations.
Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";Cook Nuclear Plant Unit 1 B3.4.6-2 Revision No. 12 RCS Loops -MODE 4 B 3.4.6 BASES ACTIONS (continued)_
minimum SDM maintains acceptable margin to subcritical operations.
The immediate Completion Times reflect the importance of maintaining operation for decay heat removal. The action to restore must be continued until one loop is restored to OPERABLE status and operation.
SURVEILLANCE SR 3.4.6.1 REQUIREMENTS This SR requires verification every 12 hours that the required RCS or RHR loop is in operation and circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. The Frequency of 12 hours is 'sufficient considering other indications and alarms available to the operator in the control room to monitor RCS and RHR loop performance.
SR 3.4.6.2 SR 3.4.6.2 requires verification of SG OPERABILITY.
SG OPERABILITY is verified by ensuring that the secondary side water level is above the lower tap of the SG wide range level instrumentation by > 420 inches. If the SG U-tubes become uncovered, the associated loop may not be capable of providing the heat sink necessary for removal of decay heat.The water level can be verified by either the wide range or the narrow range level instruments.
A narrow range level instrument
> 6% or a wide range level instrument
> 79% ensures the Surveillance Requirement limit is met. The 12 hour Frequency is considered adequate in view of other indications available in the control room to alert the operator to the loss of SG level.SR 3.4.6.3 Verification that each required pump is OPERABLE ensures that an additional RCS or RHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
Cook Nuclear Plant Unit I B 3.4.6-4 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.6-4 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 SR 3.4.6.4 RHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventingq and managing gas intrusion and accumulation is necessary for proper operation of the reguired RHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawingqs, 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operatingq conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental 6onditions, the plant configuration, or personnel safety. For these locations, alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.This SR is modified by a Note that states the SR is not reguired to be performned until-12~hours after anterina MODE 4. In a rapid shutdown.Cook Nuclear Plant Unit 1 B 3.4.6-5 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.6-5 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 there may be insufficient time to verify all susceptible locations prior to enteringq MODE 4.The 31 day Frequency takes into consideration the gqradual nature of gqas accumulation in the RHR System pipingc and the procedural controls gqoverningq system operation.
REFERENCES None.Cook Nuclear Plant Unit I B 3.4.6-6 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.6-6 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES-LCO (continued) is to prevent a low temperature overpressure event due to a thermal transient when an RCP is started.Note 4 provides for an orderly transition from MODE 5 to MODE 4 during a planned heatup by permitting removal of RHR loops from operation when at least one RCS loop is in operation.
This Note provides for the transition to MODE 4 where an RCS loop is permitted to be in operation and replaces the RCS circulation function provided by the RHR loops.RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow. An SG can perform as a heat sink via natural circulation when it has an adequate water level and is OPERABLE.Managqement of .qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with RCS loops filled, this LCO requires forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing. One loop of RHR provides sufficient circulation for these purposes.
However, one additional RHR loop is required to be OPERABLE, or the secondary side water level of at least two SGs is required to be above the lower tap of the SG wide range water level instrumentation by > 420 inches.Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO-3.4.6,"RCS Loops -MODE 4";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS A.1, A.2, B.1 and B.2 If one RHR loop is OPERABLE and either the required SGs do not have secondary side water levels above the lower tap of the SG wide range le~vel instrumentation by > 420 inches or one required RHR-loop is inoperable, redundancy for heat removal is lost. Action must be initiated immediately to restore a second RHR loop to OPERABLE status or to restore the secondary side water levels to within limit for the required SGs. Either Required Action will restore redundant heat removal paths.The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.Cook Nuclear Plant Unit I B 3.4.7-3 Revision No. 12 Cook Nuclear Plant Unit 1 B3.4.7-3 Revision No. 12 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES SURVEILLANCE REQUIREMENTS (continued) verifying proper breaker alignment and power available to each required RHR pump. If secondary side water level is above the lower tap of the SG wide range level instrumentation by > 420 inches in at least two SGs, this Surveillance is not needed. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.7.4 RHR System pipincq and components have the potential to develop voids and pockets of entrained gases. Preventinq and manaciingq ,as intrusion and accumulation is necessary for proper operation of the required RHR loop(s) and may also prevent water hammer, pump cavitation, and pumpincq of noncondensible .qas into the reactor vessel.Selection of RHR System locations susceptible to gqas accumulation is based on a review of system desigqn information, includingq pipingq and instrumentation drawings, isometric drawingqs, plan and elevation drawings, and calculations.
The design review is supplemented by system walk downs to validate the system higqh points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gqas to be trapped or difficult to remove duringq system maintenance or restoration.
Susceptible locations depend on plant and system configquration, such as stand-by versus operatingq conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow Cook Nuclear Plant Unit 1 B3475Rvso o B 3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnelsafety.
For these locations, alternative methods (e.g..operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Frequency takes into consideration the gradual nature of gqas accumulation in the RHR System piping and the procedural controls governing system operation.
REFERENCES
: 1. NRC Information Notice 95-35, "Degraded Ability of Steam Generators to Remove Decay Heat by Natural Circulation." Cook Nuclear Plant Unit 1 B 3.4.7-5 Revision No. 0 Cook Nuclear Plant Unit 1 B 3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES LCO (continued)
An OPERABLE RHR loop fs comprised of an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHR heat exchanger.
RHR pumps are OPERABLE if they. are capable of being powered and are able to provide flow if required.
Management of ,qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with loops not filled, this LCO requires core heat removal and coolant circulation by the RHR System.Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES I and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.6, "RCS Loops -MODE 4";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS A.__1 ....If one required RHR loop is inoperable, redundancy for RHR is lost.Action must be initiated to restore a second loop to OPERABLE status.The immediate Completion Time reflects the importance of maintaining the- availability of two paths for heat removal.B.1 and B.2 If no required loop is OPERABLE or the required loop is not in operation, except during conditions permitted by Note 1, all operations involving introduction of coolant into the RCS with boron concentration less than required to meet the requirements of LCO 3.1.1 must be suspended and action must be initiated immediately to restore an RHR loop to OPERABLE status and operation.
The required margin to criticality must not be reduced in this type of operation.
Suspending operations that would cause the introduction, into the RCS, of coolant with boron concentration less than required to meet the requirements of LCO 3.1 .1 is-required to assure continued safe operation.
With coolant added without forced circulation, unmixed coolant could be introduced to the core, however coolant added with boron concentration meeting the minimum SDM maintains acceptable margin to subcritical operations.
The immediate Completion Time reflects the importance of maintaining operation for heat removal. The action to restore must continue until one loop is restored to OPERABLE status and operation.
Cook Nuclear Plant Unit 1 B3.4.8-2 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE SR 3.4.8.1 REQUIREMENTS This SR requires verification every 12 hours that the required loop is in operation circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. The Frequency of 12 hours is sufficient considering other indications and alarms available to the operator in the control room to monitor RHR loop performance.
SR 3.4.8.2 Verification that each required pump is OPERABLE ensures that an additional pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.8.3 RHR System pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventinq and managingq gas intrusion and accumulation is necessary for proper operation of the RHR loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to gqas accumulation is based on a review of system design information, includingq piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations.
The desigqn review is supplemented by system walk downs to validate the system higqh points and to confirm the location and orientation of important components that can become sources of gqas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated glas at one or more susceptible locations exceeds an Cook Nuclear Plant Unit 1 B3483Rvso o B3.4.8-3 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gqas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configquration, or personnel safety. For these locations alternative methods (e.gq., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.'
The 31 day Freguency takes into consideration the gqradual nature of gqas accumulation in the RHR System pipingq and the procedural controls gqoverning system operation.
REFERENCES None.Cook Nuclear Plant Unit 1 B 3.4.8-4 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.8-4 Revision No. 0 ECCS -Operating B 3.5.2 BASES LCO (continued)
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to supply its flow to the RCS hot and cold legs. Management of cias voids is important to ECCS OPERABILITY.
The flow path for each ECCS train must maintain its designed independence to ensure that no single failure can disable both ECCS trains.APPLICABILITY In MODES 1, 2, and 3, the ECCS OPERABILITY requirements for the limiting Design Basis Accident, a large break LOCA, are based on full power operation.
Although reduced power would not require the same level of performance, the accident analysis does not provide for reduced cooling requirements in the lower MODES. MODE 2 and MODE 3 requirements are bounded by the MODE 1 analysis.This LCO is only applicable in MODE 3 and above. Below MODE 3, the SI signal setpoint is allowed to be manually bypassed by operator control, and system functional requirements are relaxed as described in LCO 3.5.3, "ECCS -Shutdown." In MODES 5 and 6, unit conditions are such that the probability of an event requiring ECCS injection is extremely low.ACTIONS A. 1 With one or more ECGS trains inoperable and at least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available, the inoperable components must be returned to OPERABLE status within 72 hours. The 72 hour Completion Time is based on an NRC reliability evaluation (Ref. 8) and is a reasonable time for repair of many ECCS components.
An ECCS train is inoperable if it is not capable of delivering minimum required flow to the RCS. Individual components are inoperable if they are not capable of performing their design function or supporting systems are not available.
The LCO requires the OPERABILITY of a number of independent subsystems.
Due to the redundancy of ECCS trains and the diversity of subsystems, the inoperability of one active component in an ECCS train does not render the ECCS incapable of performing its function.
Neither does the inoperability of two different components, each in a different ECCS train, necessarily result in a loss of function for the ECCS. This Cook Nuclear Plant Unit 1 ..- eiinN.2 B 3.5.2-5 Revision No. 24 ECCS -Operating B 3.5.2 BASES ACTIONS (continued)
C.1 Condition A is applicable with one or more ECCS trains inoperable.
The allowed Completion Time of Required Action A.1 is based on the assumption that at least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train is available.
An inoperable RHR or SI pump concurrent with a closed cross-tie valve in the affected system will result in less than 100% o'f the ECCS flow equivalent to a single OPERABLE ECCS train because there will be flow to only two RCS loops. With less than 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available, the facility is in a condition outside of the accident analyses.
Therefore, LCO 3.0.3 must be entered immediately.
SURVEILLANCE SR 3.5.2.1 REQUIREMENTS Verification of proper valve position ensures that the flow path from the ECCS pumps to the RCS is maintained.
Misalignment of these valves could render both ECCS trains inoperable.
Securing these valves in position by locking out control power ensures that they cannot change position as a result of an active failure or be inadvertently misaligned.-These valves are of the type, described in Reference 9, that can disable the function of both ECCS trains and invalidate the accident analyses.
A 12 hour Frequency is considered reasonable in view of other administrative controls that will ensure a mispositioned valve is unlikely.SR 3.5.2.2 Verifying the correct alignment for manual, power operated, and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since these were verified to be in the correct position prior to locking, sealing, or securing.
This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation.
Rather, it involves verification that those valves capable of being mispositioned are in the correct position.
The 31 day Frequency is appropriate because the*valves are operated under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating experience.
Cook Nuclear Plant Unit 1B352-ReionN.4 B 3.5.2-7 Revision No. 24 ECCS -Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued)
The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationing a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.5.2.3 Verifying that each ECCS pump's developed head at the flow test point is greater than or equal to the required developed head ensures that ECCS pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of ECCS pump performance required by the ASME OM Code (Ref. 10). Since the ECCS pumps cannot be tested with flow through the normal ECCS flow paths, they are tested on recirculation flow (RHR and SI pumps) or normal charging flow path (centrifugal charging pumps). This test confirms one point on the pump design curve and is indicative of overall performance.
Such inservice tests confirm component OPERABILITY and detect incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.5.2.4 and SR 3.5.2.5 These Surveillances demonstrate that each automatic ECCS valve actuates to the required position on an actual or simulated SI signal and that each ECCS pump starts on receipt of an actual or simulated SI signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for unplanned unit transients if the Surveillances were performed with the reactor at power. The 24 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment.
SR 3.5.2.6 Proper throttle valve position is necessary for proper ECCS performance.
These valves have stops to allow proper positioning for restricted flow to a ruptured cold leg, ensuring that the other cold legs receive at least the required minimum flow. This Surveillance verifies the mechanical stop of each listed ECCS throttle valve is in the correct position.
The 24 month Frequency is based on the same reasons as those stated in SR 3.5.2.4 and SR 3.5.2.5.Cook Nuclear Plant Unit 1 B 3.5.2-8 Revision No. 24 ECCS -Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.5.2.7 Periodic inspections of the containment sump suction inlets ensure that they are unrestricted and stay in proper operating condition.
This Surveillance verifies that the sump suction inlets are not restricted by debris and the suction inlet strainers show no evidence of structural
" distress, such as openings or gaps, which would allow debris to bypass the strainers.
The 24 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a unit outage, on the need to have access to the location.
This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience.
SR 3.5.2.8 EGCS pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventing and managling gas intrusion and accumulation is necessary for proper operation of the EGOS and may also prevent water hammer, pump cavitation, and pumping of noncondensible .qas into the reactor vessel.Selection of EGGS locations susceptible to ,qas accumulation is based on a review of system design information, includingq 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 higqh points and to confirm the location and orientation of important components that can become sources of ,qas or could otherwise cause gas to be trapped or difficult to remove duringq system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The EGOS is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suction or discharge of a pump), the S.urveillance is not met. If it is determined by subseguent evaluation that the EGOS is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brougqht within the acceptance criteria limits.EGOS locations susceptible to ,qas accumulation are monitored and, if.gas is found, the gas volume is compared to the acceptance criteria for Cook Nuclear Plant Unit 1B352-ReionN.4 B 3.5.2-9 Revision No. 24 EGOS -Operating B 3.5.2 the location.
Susceptible locations in the same system flow path which are subject to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety.For these locations, alternative methods (e.gq., operating parameters, remote monitoring) may be used to monitor the susceptible location.Monitoring is not required for susceptible locations where the maximum potential accumulated ,qas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Frequency takes into consideration the gqradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation.
REFERENCES
: 1. UFSAR, Section 1.4.7.2. 10 CFR 50.46.3. UFSAR, Section 14.3.1.4. UFSAR, Section 14.3.2.5. UFSAR, Section 14.2.4.6. UFSAR, Section 14.2.5.7. UFSAR, Section 14.3.4.8. NRC Memorandum to V. Stello, Jr., from R.L. Baer, "Recommended Interim Revisions to LCOs for ECCS Components," December 1, 1975.9. IE Information Notice No. 87-01 10. ASME, Operations and Maintenance Standards and Guides (OM Codes).Cook Nuclear Plant Unit 1 B 3.5.2-9 Revision No. 24 Cook Nuclear Plant Unit 1 B 3.5.2-9 Revision No. 24 ECCS -Shutdown B 3.5.3 BASES LCO (continued)
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold ,leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to deliver its flow to the RCS hot and cold legs. Managqement of ,qas voids is important to ECOS OPERABILITY.
APPLICABILITY In MODES 1, 2, and 3, the OPERABILITY requirements for ECCS are covered by LCO 3.5.2.In MODE 4 with RCS temperature below 350&deg;F, one OPERABLE ECCS train is acceptable without single failure consideration, on the basis of the stable reactivity of the reactor and the limited core cooling requirements.
In MODES 5 and 6, unit conditions are such that the probability of an event requiring ECCS injection is extremely low.ACTIONS .A Note prohibits the application of LCO 3.0.4.b to an inoperable ECCS centrifugal charging subsystem when entering MODE 4. There is an increased risk associated with entering MODE 4 from MODE 5 with an inoperable ECCS centrifugal charging subsystem and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.
A.1 With no ECCS RHR subsystem OPERABLE, the unit is not prepared to respond to a loss of coolant accident or to continue a cooldown using the RHR pumps and heat exchangers.
The Completion Time of immediately to initiate actions that would restore at least one ECCS RHR subsystem to OPERABLE status ensures that prompt action is taken to restore the required cooling capacity.With both RHR subsystems inoperable, it would be unwise to require the plant to go to MODE 5, where the only available heat removal system is the RHR. Therefore, the appropriate action is to initiate measures to restore one ECCS RHR subsystem and to continue the actions until the subsystem is restored to OPERABLE status.Cook Nuclear Plant Unit 1 B3.5.3-2 Revision No. 0 Containment Spray System B 3.6.6 BASES APPLI CABLE SAFETY ANALYSES (continued)
ECCS cooling effectiveness during the core reflood phase of a LOCA analysis increases with increasing containment backpressure.
For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures in accordance with 10 CFR 50, Appendix K (Ref. 4).The Containment Spray System satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO LCO During a DBA, one train of Containment Spray System is required to provide the heat removal capability assumed in the safety analyses.Additionally, a minimum of one train of the Containment Spray System, with spray pH adjusted by the Spray Additive System, is required to scavenge iodine fission products from the containment atmosphere and ensure their retention in the containment sump water. To ensure that these requirements are met, two containment spray trains must be OPERABLE with power from two safety related, independent power supplies.
Therefore, in the event of an accident, at least one train in each system operates.Each containment spray train includes a spray pump, headers, valves, heat exchangers, nozzles, piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an ESF actuation signal. Managqement of ,qas voids is important to Containment Spray System OPERABILITY.
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment and an increase in containment pressure and temperature requiring the operation of the Containment Spray System.In MODES 5 and 6, the probability and consequences of these events are reduced because of the pressure and temperature limitations of these MODES. Thus, the Containment Spray System is not required to be OPERABLE in MODE 5 or 6.ACTIONS A. 1 With one containment spray train inoperable, the affected train must be restored to OPERABLE status within 72 hours. The components in this degraded condition are capable of providing 100% of the heat removal and iodine removal needs after an accident.
The 72 hour Completion Time was developed taking into account the redundant heat removal and iodine removal capabilities afforded by the OPERABLE train and the low probability of a DBA occurring during this period.Cook Nuclear Plant Unit 1 ..- eiinN.3 B 3.6.6-4 Re-vision No. 36 Containment Spray System B 3.6.6 BASES ACTIONS (continued)
B.1 and B.2 If the affected containment spray train cannot be restored to OPERABLE status within the required Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours and to MODE 5 within 84 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.The extended interval to reach MODE 5 allows additional time and is reasonable when considering that the driving force for a release of radioactive material from the Reactor Coolant System is reduced in MODE 3.SURVEILLANCE SR 3.6.6.1 REQUIREMENTS Verifying the correct alignment of manual, power operated, and automatic valves, excluding check valves, in the Containment Spray System provides assurance that the proper flow path exists for Containment Spray System operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position since they were verified in the correct position prior to being secured. This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. This SR does not require any testing or valve manipulation.
Rather, it involves verification that those valves outside containment and capable of potentially being mispositioned, are in the correct position.The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationinq a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.6.6.2 Verifying that each containment spray pump's developed head at the flow test point is greater than or equal to the required developed head ensures that spray pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of centrifugal pump performance required by the ASME OM Code (Ref. 5).Since the containment spray pumps cannot be tested with flow through the spray headers, they are tested on bypass flow. This test confirms one point on the pump design curve and is indicative of overall performance.
Cook Nuclear Plant Unit 1B366-ReionN.2 B 3.6.6-5 Revision No. 32 Containment Spray System B 3.6.6 BASES SURVEILLANCE REQUIREMENTS (continued)
Such inservice tests confirm component OPERABILITY and detect incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.6.6.3 and SR 3.6.6.4 These SRs require verification that each automatic containment spray valve actuates to its correct position and each containment spray pump starts upon receipt of an actual or Simulated containment spray actuation signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for an unplanned transient if the Surveillances were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillances when performed at the 24 month Frequency.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
These Surveillances include a Note that states that in MODE 4, only the manual portion of the actuation signal is required.
This is acceptable since the automatic portion of the actuation signal is not required to be OPERABLE by ITS 3.3.2, "Engineered Safety Features Actuation System (ESFAS) Instrumentation." SR 3.6.6.5 With the containment spray inlet valves closed and the spray header drained of any solution, low pressure air or smoke can be blown through test connections.
This SR ensures that each spray nozzle is unobstructed and that spray coverage of the containment during an accident is not'degraded.
Because of the passive design of the nozzle, a test at 10 year intervals is considered adequate to detect obstruction of the spray nozzles.SR 3.6.6.6 Containment Spray System pipingq and components have the potential to develop voids and pockets of entrained gases. Preventing and managqingq gqas intrusion and accumulation is necessary for proper operation of the containment spray trains and may also prevent water hammer and pump cavitation.
Selection of Containment Spray System locations susceptible to gqas accumulation is based on a review of system desigqn information, including piping and instrumentation drawings, isometric drawings, plan Cook Nuclear Plant Unit 1 B 3.6.6-6 Revision No. 32 Containment Spray System B 3.6.6 and elevation drawinqs, 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The Containment Spray System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or dischargqe of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the Containment Spray System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met.Accumulated gqas should be eliminated or brought within the acceptance criteria limits.Containment Spray System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations, alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gas accumulation in the Containment Spray System pipingq and the procedural controls governing system operation.
REFERENCES
: 1. UFSAR, Section 1.4.7.2. UFSAR, Section 14.3.4.3. 10 CFR 50.49.4. 10 CFR 50, Appendix K.5. ASME, Operation and Maintenance Standards and Guides (OM Codes).Cook Nuclear Plant Unit 1 B3.6.6-6 Revision No. 32 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES LCO (continued)
An OPERABLE RHR loop includes an RHR pump, a heat exchanger, valves, piping, instruments, and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Manaciement of .qas voids is important to RHR System OPERABILITY.
The LCO is modified by a Note that allows the required operating RHR loop to be removed from operation for up to 1 hour per 8 hour period, provided no operations are permitted that would dilute the RCS boron concentration by introduction of coolant into the RCS with boron concentration less than required to meet the minimum boron concentration of LCO 3.9.1, "Boron Concentration." Boron concentration reduction with coolant at boron concentrations less than required to assure the RCS boron concentration is maintained is prohibited because uniform concentration distribution cannot be ensured without forced circulation.
This permits operations such as core mapping or alterations in the vicinity of the reactor vessel hot leg nozzles and RCS to RHR isolation valve testing. During this 1 hour period, decay heat is removed by natural convection to the large mass of water in the refueling cavity.APPLICABILITY One RHR loop must be OPERABLE and in operation in MODE 6, with the water level > 23 ft above the top of the reactor vessel flange, to provide decay heat removal. The 23 ft water level was selected because it corresponds to the 23 ft requirement established for fuel movement in LCO 3.9.6, "Refueling Cavity Water Level." Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level < 23 ft are located in LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." RHR loop requirements are met by having one RHR loop OPERABLE ACTIONS and in operation, except as permitted in the Note to the LCO.A.1 If RHR loop requirements are not met, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit I B 3.9.4-2 Revision No. 0* Cook Nuclear Plant Unit 1 B3.9.4-2 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES SURVEILLANCE SR 3.9.4.1 REQUIREMENTS This Surveillance demonstrates that the RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. The Frequency of 12 hours is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the RHR System.SR 3.9.4.2 RHR 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 loops and may also preyent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR 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 gqas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus.operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location ('or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gas ('i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subiect to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radioloaical or environmental conditions, the plant confiauration, or Cook Nuclear Plant Unit 1 B 3.9.4-4 Revision No. 0 Cook Nuclear Plant Unit 1 B3.9.4-4 Revision No. 0 k.RHR and Coolant Circulation
-High Water Level B 3.9.4.personnel safety. For these locations alternative methods ('e.gq., operatingq parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy oT the method used for monitoring the susceptible locations and trendinq of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gqradual nature of gqas accumulation in the RHR System pipingq and the procedural controls gqoverningq system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 1 B3944Rvso o B3.9.4-4 Revision No. 0 RHR and Coolant Circulation
-Low Water Level B 3.9.5 BASES LCO (continued)
This LCO is modified by a Note that allows one RHR loop to be inoperable for a period of 2 hours provided the other loop is OPERABLE and in operation.
Prior to declaring the loop inoperable, consideration should be given to the existing plant configuration.
This consideration should include time to core boiling, potential for RCS draindown, and RCS makeup capability.
This permits surveillance tests to be performed on the inoperable loop during a time when these tests are safe and possible.An OPERABLE RHR loop consists of an RHR pump, a heat exchanger, valves, piping, instruments and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Managqement of .qas voids is important to RHR System OPERABILITY.
APPLICABILITY Two RHR loops are required to be OPERABLE, and one RHR loop must be in operation in MODE 6, with the water level < 23 ft above the top of the reactor vessel flange, to provide decay heat removal. Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level > 23 ft are located in LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level." ACTIONS A.1 and A.2 If less than the required number of RHR loops are OPERABLE, action shall be immediately initiated and continued until the RHR loop is restored to OPERABLE status and to operation or until > 23 ft of water level is established above the reactor vessel flange. When the water level is-- 23 ft above the reactor vessel flange, the Applicability changes to that of LCO 3.9.4, and only one RHR loop is required to be OPERABLE and in operation.
An immediate Completion Time is necessary for an operator to initiate corrective actions.B. 1 If no RHR loop is in operation, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit 1 B3952Rvso o B3.9.5-2 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.5 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.9.5.2 Verification that the required pump is OPERABLE ensures that an additional RHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to the required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
SR 3.9.5.3 RHR System pipingq and components have the potential to develop voids and pockets of entrained gases. Preventing and managqing gqas intrusion and accumulation is necessary for proper operation of the RHR loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to ,qas accumulation is based on a review of system design information, includingq piping and instrumentation drawings, isometric drawingqs, plan and elevation drawingqs, and calculations.
The desigqn 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 gqas or could otherwise cause gqas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suctio'n or discharge of a pump), the Surveillance is not met. If it is determined by subsequent evaluation that the RHR System is not rendered inoperable by the accumulated gqas ('i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance cook Nuclear Plant Unit 1 B3.9.5-4 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.5 criteria for the location.
Susceptible locations in the same system flow path which are subject to the same ,qas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods (e.g., operatingq parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoringq the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gas accumulation in the RHR System piping and the procedural controls gqoverning system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 1 ..- evso o B3.9.5-4 Revision No. 0 Enclosure 6 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 2 TECHNICAL SPECIFICATION BASES PAGES MARKED TO SHOW PROPOSED CHANGES (FOR INFORMATION ONLY)
RCS Loops -MODE 4 B 3.4.6 BAS ES LCO (continued)
Utilization of the Note is permitted provided the following conditions are met: a. No operations are permitted that would dilute the RCS boron concentration with coolant with boron concentrations less than required to meet the requirements of LCO 3.1.1, "SHUTDOWN MARGIN (SDM)," therefore maintaining the margin to criticality.
Boron reduction with coolant at boron concentrations less than required to assure SDM is maintained is prohibited because a uniform concentration distribution throughout the RCS cannot be ensured when in natural circulation; and b. Core outlet temperature is maintained at least 10&deg;F below saturation temperature, so that no vapor bubble may form and possibly cause a natural circulation flow obstruction.
Note 2 requires that the secondary side water temperature of each SG be< 50&deg;F above each of the RCS cold leg temperatures or the pressurizer water level be < 62% before the start of an RCP with any RCS cold leg temperature
< 1 52&deg;F. This restraint is to prevent a low temperature overpressure event due to a thermal transient when an RCP is started.An OPERABLE RCS loop comprises an OPERABLE RCP and an OPERABLE SG, which has the minimum water level specified in SR 3.4.6.2.Similarly for the RHR System, an OPERABLE RHR loop comprises an OPERABLE RHR pump (either the east or west) capable of providing forced flow to an OPERABLE RHR heat exchanger.
RCPs and RHR pumps are OPERABLE if they are capable of being powered and are able to provide forced flow if required.
Management of .gas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 4, this LCO ensures forced circulation of the reactor coolant to.remove decay heat from the core and to provide proper boron mixing.One loop of either RCS or RHR provides sufficient circulation for these However, two loops consisting of any combination of RCS and RHR loops are required to be OPERABLE to meet single failure considerations.
Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";Cook Nuclear Plant Unit 2 B 3.4.6-2 Revision No. 12 RCS Loops -MODE 4 B 3.4.6 BASES ACTIONS (continued) minimum SDM maintains acceptable margin to subcritical operations.
The immediate Complet~ion Times reflect the importance of maintaining operation for decay heat removal. The action to restore must be continued until one loop is restored to OPERABLE status and operation.
SURVEILLANCE SR 3.4.6.1 REQUIREMENTS This SR requires verification every 12 hours that the required RCS or RHR loop is in operation and circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. -The Frequency of 12 hours is sufficient considering other indications and alarms avtailable to the operator in the control room to monitor RCS and RHR loop performance.
SR 3.4.6.2 SR 3.4.6.2 requires verification of SG OPERABILITY.
SG OPERABILITY is verified by ensuring that the secondary side water level is above the lower tap of the SG wide range level instrumentation by >- 418.77 inches.If the SG U-tubes become uncovered, the associated loop may not be capable of providing the heat sink necessary for removal of decay heat.The water level can be verified by either the wide range or the narrow range level instruments.
A narrow range level instrument
> 6% or a wide range level instrument
> 79% ensures the Surveillance Requirement limit is met. The 12 hour Frequency is considered adequate in view of other indications available in the control room to alert the operator to the loss of SG level.SR 3.4.6.3 Verification that each required pump is OPERABLE ensures that an additional RCS or RHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are-ensured if a pump is operating.
Cook Nuclear Plant Unit 2 B 3.4.6-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.6-4 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 SR 3.4.6.4 RHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managingl gas intrusion and accumulation is necessary for proper operation of the required RHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subsequent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations, alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the suscePtible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.This SR is modified by a Note that states the SR is not required to be performed until 12 hours after entering MODE 4. In a rapid shutdown.Cook Nuclear Plant Unit 2 B 3.4.6-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.6-4 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 there may be insufficient time to verify all susceptible locations prior to enterinq MODE 4.The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the RHR System piping and the procedural controls gloverning system operation.
REFERENCES None.Cook Nuclear Plant Unit 2 B 3.4.6-5 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.6-5 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES LCO (continued) is to prevent a low temperature overpressure event due to a thermal transient when an RCP is Started.Note 4 provides for an orderly transition from MODE 5 to MODE 4 during a planned heatup by permitting removal of RHR loops from operation when at least one RCS loop is in operation.
This Note provides for the transition to MODE 4 where an RCS loop is permitted to be in operation and replaces the RCS circulation function provided by the RHR loops.RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow. An SG can perform as a heat sink via natural circulation when it has an adequate water level and is OPERABLE.Manaqement of qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with RCS loops filled, this LCO requires forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing. One loop of RHR provides sufficient circulation for these purposes.
However, one additional RHR loop is required to be OPERABLE, or the secondary side water level of at least two SGs is required to be above the lower tap of the SG wide range water level instrumentation by > 418.77 inches.Operation in Other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.6, "RCS Loops -MODE 4";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS A.1, A.2. B.1 and B.2 If one RHR loop is OPERABLE and either the required SGs do not have secondary side water levels above the lower tap of the SG wide range level instrumentation by > 418.77 inches or one required RHR loop is inoperable, redundancy for heat removal is lost. Action must be initiated immediately to restore a second RHR loop to OPERABLE status or to restore the secondary side water levels to within limit for the required SGs. Either Required Action will restore redundant heat removal paths.The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.Cook Nuclear Plant Unit 2B3473ReionN.1 B3.4.7-3 Revision No. 12 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES SURVEILLANCE REQUIREMENTS (continued) verifying proper breaker alignment and power available to each required RHR pump. If secondary side water level is above the lower tap of the SG wide range level instrumentation by -> 418.77 inches in at least two SGs, this Surveillance is not needed. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.7.4 RHR 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 required RHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Suscentible locations in the same system flow Cook Nuclear Plant Unit 2 B 3.4.7-5 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 path which are subiect to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods (e.gq., operatingq parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitorinq is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoringq the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gqradual nature of gas accumulation in the RHR System piping and the procedural controls gqoverning system operation.
REFERENCES
: 1. NRC Information Notice 95-35, "Degraded Ability of Steam Generators to Remove Decay Heat by Natural Circulation." Cook Nuclear Plant Unit 2 B 3.4.7-5 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES LCO (continued)
An OPERABLE RHR loop is comprised of an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHR heat exchanger.
RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow if required.
Managqement of ,qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with loops not filled, this LCO requires core heat removal and coolant circulation by the RHR System.Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.6, "RCS Loops -MODE 4";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation--
Low Water Level." ACTIONS A.1 If one required RHR loop is inoperable, redundancy for RHR is lost.Action must be initiated to restore a second loop to OPERABLE status.The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.B.1 and B.2 If no required loop is OPERABLE or the required loop is not in operation, except during conditions permitted by Note 1, all operations involving introduction of coolant into the RCS with boron concentration less than required to meet the requirements of LCO 3.1.1 must be suspended and action must be initiated immediately to restore an RHR loop to OPERABLE status and operation.
The required margin to criticality must not be reduced in this type of operation.
Suspending operations that would cause the introduction, into the RCS, of coolant with boron concentration less than required to meet the requirements of LCO 3.1.1 is required to assure continued safe operation.
With coolant added without forced circulation, unmixed coolant could be introduced to the core, however coolant added with boron concentration meeting the minimum SDM maintains acceptable margin to subcritical operations.
The immediate Completion Time reflects the importance of maintaining operation for heat removal. The action to restore must continue until one loop is restored to OPERABLE status and operation.
Cook Nuclear Plant Unit 2 B3482Rvso o B3.4.8-2 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE SIR 3.4.8.1 REQUIREMENTS This SR requires verification every 12 hours that the required loop is in operation circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. The Frequency of 12 hours is sufficient considering other indications and alarms available to the operator in the control room to monitor IRHR loop performance.
SR 3.4.8.2 Verification that each required pump is OPERABLE ensures that an additional pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.8.3 RHIR 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 loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gqas into the reactor vessel.Selection of IRHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawingqs, 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHIR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated glas at one or more susceptible locations exceeds an Cook Nuclear Plant Unit 2 B3483Rvso o B3.4.8-3 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subsequent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configquration, or personnel safety. For these locations alternative methods (e.gq., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Freguency takes into consideration the gqradual nature of gas accumulation in the RHR System pipingq and the procedural controls gqoverningq system operation.
REFERENCES None.Cook Nuclear Plant Unit 2 B 3.4.8-3 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.8-3 Revision No. 0 ECCS -Operating B 3.5.2 BASES LCO (continued)
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to supply its flow to the RCS hot and cold legs. Managqement of .qas voids is important to ECCS OPERABILITY.
The flow path for each ECCS train must maintain its designed independence to ensure that no single failure can disable both ECCS trains. -APPLICABILITY In MODES 1, 2, and 3, the ECCS OPERABILITY requirements for the limiting Design Basis Accident, a large break LOCA, are based on full power operation.
Although reduced power would not require the same level of performance, the accident analysis does not provide for reduced cooling requirements in the lower MODES. MODE 2 and MODE 3 requirements are bounded by the MODE I analysis.This LCO is only applicable in MODE 3 and above. Below MODE 3, the SI signal setpoint is allowed to be manually bypassed by operator control, and system functional requirements are relaxed as described in LCO 3.5.3, "ECCS -Shutdown." In MODES 5 and 6, unit conditions are such that the probability of an event requiring ECCS injection is extremely low.ACTIONS A. 1 With one or more ECCS trains inoperable and at least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available, the inoperable components must be returned to OPERABLE status within 72 hours. The 72 hour Completion Time is based on an NRC reliability evaluation (Ref. 8) and is a reasonable time for repair of many ECCS components.
An ECCS train is inoperable if it is not capable of delivering minimum required flow to the RCS. Individual components are inoperable if they are not capable of performing their design function or supporting systems are not available.
The LCO requires the OPERABILITY of a number of independent subsystems.
Due to the redundancy of ECCS trains and the diversity of subsystems, the inoperability of one active component in an ECCS train does not render the ECCS incapable of performing its function.
Neither does the inoperability of two different components, each in a different ECCS train, necessarily result in a loss of function for the ECCS.Cook Nuclear Plant Unit 2B352-ReionN.0 B 3.5.2-5 Revision No. 30 ECCS -Operating B 3.5.2 BASES ACTIONS (continued) train available, the facility is in a condition outside of the accident analyses.
Therefore, LCO 3.0.3 must be entered immediately.
SURVEILLANCE SR 3.5.2.1 REQUIREMENTS Verification of proper valve position ensures that the flow path from the ECCS pumps to the ROS is maintained.
Misalignment of these valves could render both ECCS trains inoperable.
Securing these valves in position by locking out control power ensures that they cannot change position as a result of an active failure or be inadvertently misaligned.
These valves are of the type, described in Reference 9, that can disable the function of both ECCS trains and invalidate the accident analyses.
A 12 hour Frequency is considered reasonable in view of other-administrative controls that will ensure a mispositioned valve is unlikely.SR 3.5.2.2 Verifying the correct alignment for manual, power operated, and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since these were verified to be in the correct position prior to locking, sealing, or securing.
This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation.
Rather, it involves verification that those valves capable of being mispositioned are in the correct position.
The 31 day Frequency is appropriate because the valves are operated under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating experience.
The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationingq a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.5.2.3 Verifying that each ECCS pump's developed head at the flow test point is greater than or equal to the required developed head ensures that ECCS pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of ECCS pump performance required by the ASME OM Code (Ref. 10). Since the ECCS Cook Nuclear Plant Unit 2 B 3.5.2-7 Revision No. 30 ECCS -Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued) pumps cannot be tested with flow through the normal ECCS flow paths, they are tested on recirculation flow (RHR and SI pumps) or normal charging flow path (centrifugal charging pumps). This test confirms one point on the pump design curve and is indicative of overall performance.
Such inservice tests confirm component OPERABILITY and detect incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.5.2.4 and SR 3.5.2.5 These Surveillances demonstrate that each automatic ECCS valve actuates to the required position on an actual or simulated SI signal and that each ECCS pump starts on receipt of an actual or simulated SI signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for unplanned unit transients if the Surveillances were performed with the reactor at power. The 24 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment.
SR 3.5.2.6 Proper throttle valve position is necessary for proper ECCS performance.
These valves have stops to allow proper positioning for restricted flow to a ruptured cold leg, ensuring that the other cold legs receive at least the required minimum flow. This Surveillance verifies the mechanical stop of each listed ECOS throttle valve is in the correct position.
The 24 month Frequency is based on the same reasons as those stated in SR 3.5.2.4 and SR 3.5.2.5.SR 3.5.2.7 Periodic inspections of the containment sump suction inlets ensure that they are unrestricted and stay in proper operating condition.
This Surveillance verifies that the sump suction inlets are not restricted by debris and the suction inlet strainers show no evidence of structural distress, such as openings or gaps, which would allow debris to bypass the strainers.
The 24 month FrequencY is based on the need to perform this Surveillance under the conditions that apply during a unit outage, on the need to have access to the location.
This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience.
Cook Nuclear Plant Unit 2 B 3.5.2-8 Revision No. 16 Cook Nuclear Plant Unit 2 B3.5.2-8 Revision No. 16 ECCS -Operating B 3.5.2 SR 3.5.2.8 ECCS pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventing and managingq gas intrusion and accumulation is necessary for proper operation of the ECCS and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of ECCS locations susceptible to gqas accumulation is based on a review of system design information, including pipingq and instrumentation drawings, isometric drawingqs, plan and elevation drawingqs, 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 gqas or could otherwise cause gqas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The ECCS is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the ECCS is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.EGOS locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subiect to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configquration, or personnel safety.For these locations, alternative methods (e.g., operatingq parameters, remote monitoring) may be used to monitor the susceptible location.Monitoringq is not reguired for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gqas accumulation in the ECOS pipingq and the procedural controls gqoverning system operation.
Cook Nuclear Plant Unit 2B352-ReionN.1 B 3.5.2-8 Revision No. 16 ECCS -Operating B 3.5.2 BASES REFERENCES 1.2.3.4.5.6.7.8.UFSAR, Section 1.4.7.10 CFR 50.46.UFSAR, Section 14.3.1.UFSAR, Section 14.3.2.UFSAR, Section 14.2.4.UFSAR, Section 14.2.5.UFSAR, Section 14.3.4.NRC Memorandum to V. Stello, Jr., from R.L. Baer, "Recommended Interim Revisions to LCOs for ECOS Components," December 1, 1975.IE Information Notice No. 87-01.ASME, Operations and Maintenance Standards and Guides (OM Codes).9.10.Cook Nuclear Plant Unit 2 B 3.5.2-9 Revision No. 16 Cook Nuclear Plant Unit 2 B 3.5.2-9 Revision No. 16 EGOS -Shutdown B 3.5.3 BASES LCO (continued)
During an event requiring ECCS actuation, a fiow path is required to provide an abundant supply of water from the RWST to the RCS via the EGGS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to deliver its flow to the RCS hot and cold legs. Managqement of gas voids is important to EGOS OPERABILITY.
APPLICABILITY In MODES 1, 2, and 3, the OPERABILITY requirements for EGOS are covered by LCO 3.5.2.In MODE 4 with RCS temperature below 350&deg;F, one OPERABLE EGGS train is acceptable without single failure consideration, on the basis of the stable reactivity of the reactor and the limited core cooling requirements.
In MODES 5 and 6, unit conditions are such that the probability of an event requiring EGGS injection is extremely low.ACTIONS A Note prohibits the application of LCO 3.O.4.b to an inoperable ECOS centrifugal charging subsystem when entering MODE 4. There is an increased risk associated with entering MODE 4 from MODE 5 with an inoperable EGGS centrifugal charging subsystem and the provisions of LGO 3.O.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.
A.1 With no EGOS RHR subsystem OPERABLE, the unit is not prepared to respond to a loss of coolant accident or to continue a cooldown using the RHR pumps and heat exchangers.
The Completion Time of immediately to initiate actions that would restore at least one EGOS RHR subsystem to OPERABLE status ensures that prompt action is taken to restore the required cooling capacity.With both RHR subsystems inoperable, it would be unwise to require the plant to go to MODE 5, where the only available heat removal system is the RHR. Therefore, the appropriate action is to initiate measures to restore one EGOS RHR subsystem and to continue the actions until the subsystem is restored to OPERABLE status.Cook Nuclear Plant Unit 2 B3532Rvso o B 3.5.3-2 Revision No. 0 Containment Spray System B 3.6.6 BASES APPLI CABLE SAFETY ANALYSES (continued)
ECCS cooling effectiveness during the core reflood phase of a LOCA analysis increases with increasing containment backpressure.
For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures in accordance with 10 CFR 50, Appendix K (Ref. 4).The Containment Spray System satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO During a DBA, one train of Containment Spray System is required to provide the heat removal capability assumed in the safety analyses.Additionally, a minimum of one train of the Containment Spray System, with spray pH adjusted by the Spray Additive System, is required to scavenge iodine fission products from the containment atmosphere and ensure their retention in the containment sump water. To ensure that these requirements are met, two containment spray trains must be OPERABLE with power from two safety related, independent power supplies.
Therefore, in the event of an accident, at least one train in each system operates.Each containment spray train includes a spray pump, headers, valves, heat exchangers, nozzles, piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an ESF actuation signal. Managqement of gas voids is important to Containment Spray System OPERABILITY.
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment and an increase in containment pressure and temperature requiring the operation of the Containment Spray System.In MODES 5 and 6, the probability and consequences of these events are reduced because of the pressure and temperature limitations of these MODES. Thus, the Containment Spray System is not required to be OPERABLE in MODE 5 or 6.ACTIONS A.1 With one containment spray train inoperable, the affected train must be restored to OPERABLE status within 72 hours. The components in this degraded condition are capable of providing 100% of the heat removal and iodine removal needs after an accident.
The 72 hour Completion Time was developed taking into account the redundant heat removal and iodine removal capabilities afforded by the OPERABLE train and the low probability of a DBA occurring during this period.Cook Nuclear Plant Unit 2B3664ReionN.5 B 3.6.6-4 Revision No. 35 Containment Spray System B 3.6.6 BASES ACTIONS (continued)
B.1 and B.2 If the affected containment spray train cannot be restored to OPERABLE status within the required Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours and to MODE 5 within 84 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.The extended interval to reach MODE 5 allows additional time and is reasonable when considering that the driving force for a release of radioactive material from the Reactor Coolant System is reduced in MODE 3.SURVEILLANCE SR 3.6.6.1 REQUIREMENTS Verifying the correct alignment of manual, power operated, and automatic valves, excluding check valves, in the Containment Spray System provides assurance that the proper flow path exists for Containment Spray System operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position since they were verified in the correct position prior to being secured. This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. This SR does not require any testing or valve manipulation.
Rather, it involves verification that those valves outside containment and capable of potentially being mispositioned, are in the correct position.The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationing a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.6.6.2 Verifying that each containment spray pump's developed head at the flow test point is greater than or equal to the required developed head ensures that spray pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of centrifugal pump performance required by the ASME OM Code (Ref. 5).Since the containment spray pumps cannot be tested with flow through the spray he'aders, they are tested on bypass flow. This test confirms one point on the pump design curve and is indicative of overall performance.
Such inservice tests confirm component OPERABILITY and detect Cook Nuclear Plant Unit 2B3665ReionN.0 B 3.6.6-5 Revision No. 30 Containment Spray System B 3.6.6 BASES SURVEILLANCE REQUIREMENTS (continued) incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.6.6.3 and SR 3.6.6.4-These SRs require verification that each automatic containment spray valve actuates to its correct position and each containment spray pump starts upon receipt of an actual or simulated containment spray actuation signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for an unplanned transient if the Surveillances were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillances when performed at the 24 month Frequency.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
These Surveillances include a Note that states that in MODE 4, only the manual portion of the actuation signal is required.
This is acceptable since the automatic portion of the actuation signal is not required to be OPERABLE by ITS 3.3.2, "Engineered Safety Features Actuation System (ESFAS) Instrumentation." SR 3.6.6.5 With the containment spray inlet valves closed and the spray header drained of any solution, low pressure air or smoke can be blown through test connections.
This SR ensures that each spray nozzle is unobstructed and that spray coverage of the containment during an accident is not degraded.
Because of the passive design of the nozzle, a test at 10 year intervals is considered adequate to detect obstruction of the spray nozzles.SR 3.6.6.6 Containment Spray System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managingl gas intrusion and accumulation is necessary for proper operation of the containment spray trains and may also prevent water hammer and pump cavitation.
Selection of Containment Spray System locations susceptible to gqas accumulation is based on a review of system design information, includingq pipingq 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 Cook Nuclear Plant Unit 2B366-ReionN.1 B 3.6.6-6 Revision No. 31 Containment Spray System B 3.6.6 and to confirm the iocation 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The Containment Spray System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the Containment Spray System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met.Accumulated gqas should be eliminated or brought within the acceptance criteria limits.Containment Spray System locations susceptible to gqas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoringl a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiologqical or environmental conditions, the plant configquration, or personnel safety. For these locations, alternative methods (e.g.. operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gqas accumulation in the Containment Spray System piping and the procedural controls gqoverningq system operation.
REFERENCES
: 1. UFSAR, Section 1.4.7.2. UFSAR, Section 14.3.4.3. 10 CFR 50.49.4. 10 CFR 50, Appendix K.5. ASME, Operation and Maintenance Standards and Guides (OM Codes).Cook Nuclear Plant Unit 2 B3.6.6-6 Revision No. 31 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES LCO (continued)
An OPERABLE RHR loop includes an RHR pump, a heat exchanger, valves, piping, instruments, and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Manaqement of gas voids is important to RHR System OPERABILITY.
The LCO is modified by a Note that allows the required operating RHR loop to be removed from operation for up to 1 hour per 8 hour period, provided no operations are permitted that would dilute the RCS boron concentration by introduction of coolant into the RCS with boron-concentration less than required to meet the minimum boron concentration of LCO 3.9.1, "Boron Concentration." Boron concentration reduction with coolant at boron concentrations less than required to assure the RCS boron concentration is maintained is prohibited because uniform concentration distribution cannot be ensured without forced circulation.
This permits operations such as core mapping or alterations in the vicinity of the reactor vessel hot leg nozzles and RCS to RHR isolation valve testing. During this 1 hour period, decay heat is removed by natural convection to the large mass of water in the refueling cavity.APPLICABILITY One RHR loop must be OPERABLE and in operation in MODE 6, with the water level > 23 ft above the top of the reactor vessel flange, to provide decay heat removal. The 23 ft water level was selected because it corresponds to the 23 ft requirement established for fuel movement in LCO 3.9.6, "Refueling Cavity Water Level." Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level < 23 ft are located in LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS RHR loop requirements are met by having one RHR loop OPERABLE and in operation, except as permitted in the Note to the LCO.A.1 If RHR loop requirements are not met, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit 2 B3942Rvso o B3.9.4-2 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES SURVEILLANCE SR 3.9.4.1 REQUIREMENTS This Surveillance demonstrates that the RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. The Frequency of 12 hours is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the RHR System.SR 3.9.4.2 RHR 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 loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to gqas accumulation is based on a review of system design information, includingq 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 gqas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configquration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subiect to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods ('e.g., operating Cook Nuclear Plant Unit 2 B3944Rvso o B3.9.4-4 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.4 parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitorinq is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenqe system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Frequency takes into consideration the gradual nature of glas accumulation in the RHR System pipingq and the procedural controls gqoverning system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 2 B 3.9.4-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.4-4 Revision No. 0 RHR and Coolant Circulation
-Low Water Level B 3.9.5 BASES LCO (continued)
This LCO is modified by a Note that allows one RHR loop to be inoperable for a period of 2 hours provided the other loop is OPERABLE and in operation.
Prior to declaring the loop inoperable, consideration should be given to the existing plant configuration.
This consideration should include time to core boiling, potential for RCS draindown, and RCS makeup capability.
This permits surveillance tests to be performed on the inoperable loop during a time when these tests are safe and possible.An OPERABLE RHR loop consists of an RHR pump, a heat exchanger, valves, piping, instruments and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Managqement of ,qas voids is important to RHR System OPERABILITY.
APPLICABILITY Two RHR loops are required to be OPERABLE, and one RHR loop must be in operation in MODE 6, with the water level < 23 ft above the top of the reactor vessel flange, to providedecay heat removal. Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level > 23 ft are located in LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level." ACTIONS A.1 and A.2 If less than the required number of RHR loops are OPERABLE, action shall be immediately initiated and continued until the RHR loop is restored to OPERABLE status and to operation or until > 23 ft of water level is established above the reactor vessel flange. When the water level is-> 23 ft above the reactor vessel flange, the Applicability changes to that of LCO 3.9.4, and only one RHR loop is required to be OPERABLE and in operation.
An immediate Completion Time is necessary for an Operator to initiate corrective actions.B. 1 If no RHR loop is in operation, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit 2 B 3.9.5-2 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.5-2 Revision No. 0 IRHR and Coolant Circulation
-Low Water Level B 3.9.5 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.9.5.2 Verification that the required pump is OPERABLE ensures that an additional IRHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to the required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SIR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
SR 3.9.5.3 RHR System pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventing and managingq gas intrusion and accumulation is necessary for proper operation of the IRHR loops and may also prevent water hammer, pump cavitation, and pumpingq of non condensible gas into the reactor vessel.Selection of RHIR 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 bysystem 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.IRHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow Cook Nuclear Plant Unit 2 B 3.9.5-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.5-4 Revision No. 0 RHR and Coolant Circulation
-Low Water Level B 3.9.5 path which are subiect to the same gqas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods ('e.g., operatinq parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challengqe system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Frequency takes into consideration the gqradual nature of gqas accumulation in the RHR System piping and the procedural controls gqoverning system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 2 B 3.9.5-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.5-4 Revision No. 0 zNIN nin Mcia oe MINHIANA Coiak Michlgan Power MICHIGANn CookNula Plant A unt o Amricn Elctrc PwerBridgrnan, Ml 49106 A unt o~meica Eletri PoerIndtanaMichigan Power~corn January 29, 2016 AEP-NRC-201 6-07 10 CFR 50.90 Docket Nos. 50-315 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk ..Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 1 and Unit 2 License Amendment Request to Revise Technical Specifications to Adopt Technical Specifications Task Force-523, "Generic Letter 2008-01, Managing Gas Accumulation," Using the Consolidated Line Item Improvement Process
 
==References:==
: 1. Technical Specifications Task Force (TSTF)-523, "Generic Letter 2008-01, Managing Gas Accumulation," Revision 2, dated February 21, 2013, Agencywide Documents Access and Management System (ADAMS) Accession No. ML13053A075.
: 2. Notice of Availability of the "TSTF-523, 'Generic Letter 2008-01, Managing Gas Accumulation,'
Using the Consolidated Line Item Improvement Process," dated December 23, 2013, ADAMS ACcession No. ML13255A167.
: 3. Letter from J. P. Gebbie, Indiana Michigan Power Company (I&M), to Nuclear Regulatory Commission (NRC),. "Donald C. Cook Nuclear Plant Units 1 and 2 'Evaluation of TSTF-523,"Generic Letter 2008-01, Managing Gas Accumulation" dated March 7, 2014, ADAMS Accession No. ML14070A344.
: 4. Letter from J. P. Gebbie, I&M, to NRC, "Donald C. Cook Nuclear Plant Unit 1 and Unit 2-Commitment Schedule Change Related to Technical Specification Task Force-523," dated June 24, 2015, ADAMS Accession No. ML15181A256.
In accordance with the provisions of Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR), Indiana Michigan Power Company (I&M) is submitting a request for an amendment to the Technical Specifications (TS) for Donald C. Cook Nuclear Plant, Units 1 and 2. ..The proposed amendment would modify TS requirements to address Generic Letter 2008-01,"Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (GL 2008-01), as described in Technical Specifications Task Force (TSTF)-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation" (Reference 1). A Notice of Availability of TSTF-523 was published on December 23, 2013 (Reference 2).
U. S. Nuclear Regulatory Commission AEP-NRC-201 6-07 Page 2 l&M-committed in Reference 3 to conduct additional evaluation of the issues described in GL 2008-01, and to submit a license amendment request (LAR) based on the evaluation following Nuclear Regulatory Commission (NRC) approval of TSTF-523 (Reference 2). In Reference 4, I&M provided information regarding the evaluation and revised the commitment date for submitting the LAR. The evaluation to review affected systems and identify locations susceptible to gas accumulation has been completed.
This submittal satisfies the commitment to submit an [AR.Enclosure 1 to this letter provides an affirmation statement.
Enclosure 2 provides a description and assessment of the proposed change. Enclosures 3 and 4 provide existing Unit 1 and Unit 2 TS pages, respectively, marked up to show the proposed changes. Enclosures 5 and 6 provide existing Unit 1 and Unit 2 TS Bases pages, respectively, marked up to show the proposed changes.TS Bases markups are included for information only. Changes to the existing TS Bases, consistent with the technical and regulatory analyses, will be implemented under the TS Bases Control Program. New clean Unit 1 and Unit 2 TS pages, with proposed changes incorporated will be provided to the NRC Licensing Project Manager (PM) when requested.
Approval of the proposed amendment is requested in accordance with the normal NRC review schedule for such changes. Once approved, the amendment will be implemented within 180 days.I&M recently submitted an [AR to implement a TS surveillance frequency control program, which has not yet been approved by the NRC. The coordination of that [AR with the amendment request in this letter, and the potential to supplement or revise this request following approval of that [AR, have been discussed with the NRC PM. Copies of this letter are being transmitted to the Michigan Public Service Commission and Michigan Department of Environmental Quality, in accordance with the requirements of 10 CFR 50.91.There are no new regulatory commitments made in this letter. Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649.Sincerely, Q. Lies Site Vice President TLC/mll
 
==Enclosures:==
: 1. Affirmation
: 2. Evaluation of the Proposed License Amendment 3. Donald C. Cook Nuclear Plant Unit 1. Technical Specification Pages Marked To Show Proposed Changes 4. Donald C. Cook Nuclear Plant Unit 2 Technical Specification Pages Marked To Show Proposed Changes U. S. Nuclear Regulatory Commission Page 3 AEP-NRC-201 6-07 5. Donald C. Cook Nuclear Plant Unit 1 Technical Specification Bases Pages Marked To Show Proposed Changes (For Information Only)6. Donald C. Cook Nuclear Plant Unit 2 Technical Specification Bases Pages Marked To.Show Proposed Changes (For Information Only)c: R. J. Ancona, MPSC A. W. Dietrich, NRC, Washington, D.C.MDEQ -RMD/RPS NRC .Resident Inspector C. D. Pederson, NRC, Region Ill A. J.-Williamson, AEP Ft. Wayne, w/o enclosures Enclosure 1Ito AEP-NRC-2016-07 AFFIRMATION I, Q. Shane Lies, being duly sworn, state that I am the Site Vice President of Indiana Michigan Power Company (I&M), that I am authorized to sign and file this request with the U. S. Nuclear Regulatory Commission on behalf of l&M, and that the statements made and the matters set forth herein pertaining to I&M are true and correct to the best of my knowledge, information, and belief.Indiana Michigan Power Company Q. Shane Lies Site Vice President SWORN TO AND SUBSCRIBED BEFORE ME THIS DAY OF
,4 2016 My Commission Expires -o.tZ_DANIELLE BUJRGOYNE Notary Public, State of Michigan My Co unty' of Berrien My Commission Expires 0 421 A ctingln the County of 4Sy01 Enclosure 2 to AEP-NRC-2016-07 Evaluation of the Proposed License Amendment
 
==1.0 DESCRIPTION==
 
The proposed change revises or adds Surveillance Requirements (SRs) to verify that the system locations susceptible to gas accumulation are sufficiently filled with water and to provide allowances, which permit performance of the verification.
The changes are being made to address the concerns discussed in Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems." The proposed amendment is consistent with Technical Specification Task Force (TSTF)Traveler-523, Revision 2, "Generic Letter 2008-01, Managing Gas Accumulation." 2.0 ASSESSMENT
 
===2.1 Applicability===
 
of Published Safety Evaluation Indiana Michigan Power Company (I&M) has reviewed the model safety evaluation dated December 23, 2013, Agency~wide Documents Access and Management Systems, Accession No. ML1 3255A1 69 as part of the Federal Register Notice of Availability.
This review included a review of the Nuclear Regulatory Commission (NRC) staff's evaluation, as well as the information provided in TSTF-523.
As described in the subsequent paragraphs, I&M has concluded that the justifications presented in the TSTF-523 proposal and the model safety evaluation prepared by the NRC staff are applicable to Donald C. Cook Nuclear Plant (CNP), Units 1 and 2, and justify this amendment for the incorporation of the changes to the CNP Technical Specifications (TS).The TSTF Traveler and model Safety Evaluation discuss the applicable regulatory requirements and guidance, including the Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR 50), Appendix A, General Design Criteria (GDC). CNP was not licensed to 10 CFR 50, Appendix A, GDC. Conformance to the applicable GDC is discussed in Section 1.4 of the CNP Updated Final Safety Analysis Report. This difference does not alter the conclusion that the proposed change is applicable to CNP.2.2 Optional Chancies and Variations l&M is proposing the following variations from the TS changes described in TSTF-523, Revision 2, or the applicable parts of the NRC staff's model safety evaluation dated December 23, 2013. _The CNP TS do not have the existing SR revised by TSTF-523 and some sections utilize different numbering than the Standard Technical Specifications (STS) for Westinghouse Plants (NUREG-1431), on which TSTF-523 was based. Implementation of TSTF-523 will add a new SR to TS 3.5.2, [Emergency Core Cooling System] "ECCS -Operating." Specifically, Westinghouse STS SR 3.5.2.3 was not used when I&M converted to STS. For CNP TS 3.5.2, SR 3.5.2.3 from TSTF-523 will be inserted after CNP TS SR 3.5.2.7 as new SR 3.5.2.8, so the numbering of the existing SRs will not change.
Enclosure 2 to AEP-NRC-2016-07 Pg Page 2 Additionally, because of the insertion of TS SR 3.5.2.8, CNP TS SR 3.5.3.1 is being revised with updated numbering from TS 3.5.2. Finally, TSTF-523 TS 3.9.5, [Residual Heat Removal] "RHR and Coolant Circulation
-High Water Level," and 3.9.6, "RHR and Coolant Circulation
-Low Water Level," are numbered 3.9.4 and 3.9.5, respectively, in the CNP TS.These differences are administrative and do not affect the applicability of TSTF-523 to the CNP TS.3.0 REGULATORY ANALYSIS 3.1 No Siqnificant Hazards Consideration Determination I&M requests adoption of TSTF-523, Revision 1, "Generic Letter 2008-01, Managing Gas Accumulation," which is an approved change to the STS, into the CNP Unit 1 and Unit 2 TS.The proposed change revises or adds SRs to verify that the system locations susceptible to gas accumulation are sufficiently filled with water and to provide allowances, which permit performance of the verification.
I&M has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50:92, "Issuance of amendment," as discussed below: 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response:
No.SThe proposed change revises or adds SRs that require verification that the ECCS, RHR System, and the Containment Spray (CTS) System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification.
Gas accumulation in the subject systems is not an initiator of any accident previously evaluated.
As a result, the' probability of any accident previously evaluated is not significantly increased.
The proposed SRs ensure that the subject systems continue to be capable to perform their assumed safety function and are not rendered inoperable due to gas accumulation.
Thus, the consequences of any accident previously evaluated are not significantly increased.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
: 2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Response:
No.The proposed change revises or adds SRs that require verification that the ECCS, the RHR System, and the CTS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification.
The proposed change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation.
In addition, the Enclosure 2 to AEP-NRC-2016-07 Pg Page 3 proposed change does not impose any new or different requirements that could initiate an accident.
The proposed change does not alter assumptions made in the safety analysis and is consistent with the safety analysis assumptions.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
: 3. Does the proposed change involve a significant reduction in a margin of safety?Response:
No.The proposed change revises or adds SRs that require verification that the ECCS, the RHR System, and the CTS System are not rendered inoperable due to accumulated gas and to provide allowances which permit performance of the revised verification.
The proposed change adds new requirements to manage gas accumulation in order to ensure the subject systems are capable of performing their assumed safety functions.
The proposed SRs are more comprehensive than the current SRs and will ensure that the assumptions of the safety analysis are protected.
The proposed change does not adversely affect any current plant safety margins or the reliability of the equipment assumed in the safety analysis.
Therefore, there are no changes being made to any safety analysis assumptions, safety limits or limiting safety system settings that would adversely affect plant safety as a result of the proposed change.Therefore, the proposed change does not involve a significant reduction in a margin of safety.Based on the above, I&M concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of "no significant hazards consideration" is justified.
 
===4.0 ENVIRONMENTAL===
 
EVALUATION The proposed change 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 SR. However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure..
Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Therefore, pursuant to 10 CFR 51 .22Cb)_,.
no _environmental impact statement or environmental assessment need be prepared in connection with the proposed change.
Enclosure 3 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 1 TECHNICAL SPECIFICATION PAGES MARKED TO SHOW PROPOSED CHANGES RCS Loops -MODE 4 3.4.6 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. Two required loops B.1 Suspend operations that Immediately inoperable, would cause introduction of coolant into the RCS with OR boron concentration less than required to meet the Required loop not in requirements of LCO 3.1.1.operation.
AND B.2 Initiate action to restore one Immediately loop to OPERABLE status and operation.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.6.1 Verify required RHR or RCS loop is in operation.
12 hours SR 3.4.6.2 Verify SG secondary side water levels are above the 12 hours lower tap of the SG wide range level instrumentation by > 420 inches for required RCS loops.SR 3.4.6.3---------------------NOTE---------------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required pump.SR 3.4.6.4 -- --NOTE----------------.......
Not required to be performed until 12 hours after enteringq Mode 4.Verify required RHR loop locations susceptible to 31 days ,qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1346-AmnetNo28 3.4.6-2 Amendment No. 287 RCS Loops -MODE 5, Loops Filled 3.4.7 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.7.1 Verify required RHR loop is in operation.
12 hours SR 3.4.7.2 Verify SG secondary side water level is above the 12 hours lower tap of the SG wide range level instrumentation by > 420 inches in required SGs.SR 3.4.7.3------------NOTE----...................
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.7.4 Verify required RHR loop locations susceptible to 31 days.gas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1347-AmnetNo28 3.4.7-3 Amendment No. 287 RCS Loops -MODE 5, Loops Not Filled 3.4.8 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. No required RHR loop 8.1 Suspend operations that Immediately OPERABLE.
would cause introduction of coolant into the RCS with OR boron concentration less i than required to meet Required RHR loop not requirements of LCO 3.1 .1.in operation.
AND 8.2 Initiate action to restore one Immediately RHR loop to OPERABLE status and operation.
SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.4.8.1 Verify required RHR loop is in operation.
12 hours SR 3.4.8.2 ...........
NOTE............--OT Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.8.3 Verify RHR loop locations susceptible to ,qas accumulation are sufficiently filled with water.31 days Cook Nuclear Plant Unit 13482AmnetNo27 3.4.8-2 Amendment No. 287 ECCS -Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify the following valves are in the listed position with power to the valve operator removed.12 hours Number 1 -1MO-261 1 -1MO-262 1 -1MO-263 1-1MO-315 1 -1MO-325 1-I1MO-390 1 -ICM-305 1 -ICM-306 Position Open Open Open Closed Closed Open Closed Closed Function SI suction line Mini flow line Mini flow line Low head SI to hot leg Low head SI to hot leg RWST to RHR Sump line Sump line SR 3.5.2.2 ...........
...... .NOTE -........
...........
31 days Not required to be met for system vent flow paths opened under administrative control.____________Verify each ECCS manual, power operated, and automatic valve in the flow path, that is not locked, sealed, or otherwise secured in position, is in the correct position.SR 3.5.2.3 Verify each ECCS pump's developed head at the In accordance test flow point is greater than or equal to the with the Inservice required developed head. Testing Program SR 3.5.2.4 Verify each ECCS automatic valve in the flow path 24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.5.2.5 Verify each ECCS pump starts automatically on an 24 months actual or simulated actuation signal.Cook Nuclear Plant Unit 1352-AmnetNo28 3.5.2-2 Amendment No. 287 ECCS -Operating 3.5.2 SURVEILLANCE REQUI REMENTS ('continued)
SURVEILLANCE FREQUENCY SR 3.5.2.6 Verify, for each ECCS throttle valve listed below, each position stop is in the correct position.24 months Valve Number 1-SI-121 N 1-S1-121 S 1-S1-141 Li 1-S1-141 L2 1-S1-141 L3 1-S1-141 L4 SR 3.5.2.7 Verify, by visual inspection, each ECCS train 24 months containment sump suction inlet is not restricted by debris and the suction inlet strainers show no evidence of structural distress or abnormal corrosion.
SR 3.5.2.8 Verify ECCS locations susceotible to aas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1 3523AedetN.2~
9 3.5.2-3 Amendment No. 287, 299 ECCS -Shutdown 3.5.3 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.3.1--------------
NOTE- -------For SR 3.5.2.2, the SR is modified to allow the valves to not be in the correct position, provided they can be aligned to the correct position.The following SRs are applicable for all equipment required to be OPERABLE: In accordance with applicable SRs SR 3.5.2.2, SR 3.5.2.3, SR 3.5.2.6, ai~d SR 3.5.2.7, and SR 3.5.2.8 Cook Nuclear Plant Unit 1 ..- mnmn o 8 3.5.3-2 Amendment No. 287 Containment Spray System 3.6.6 3.6 CONTAINMENT SYSTEMS 3.6.6 Containment Spray System LCO 3.6.6 APPLICABILITY:
Two containment spray trains shall be OPERABLE.MODES 1, 2, 3, and 4.ACTIONS_____
___CONDITION REQUIRED ACTION COMPLETION TIME A. One containment spray A.1 Restore containment spray 72 hours train inoperable, train to OPERABLE status.B. Required Action and B.1 Be in MODE 3. 6 hours associated Completion Time not met. AND B.2 Be in MODE 5. 84 hours SURVEILLANCE REQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.6.6.1------------NOTE----------31 days Not required to be met for system vent flow paths opened under administrative control._____________Verify each containment spray manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.Cook Nuclear Plant Unit 1 ..- mnmn o 8 3.6.6-1 Amendment No. 287 Containment Spray System 3.6.6 SURVEILLANCE REQUI REMENTS (continued)________
SURVEILLANCE FREQUENCY SR 3.6.6.2 Verify each containment spray pump's developed In accordance head at the flow test point is greater than or equal to with the Inservice the required developed head. Testing Program SR 3.6.6.3---------------------NOTE--------------
In MODE 4, only the manual portion of the actuation signal is required.Verify each automatic containment spray valve in 24 months the flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.6.6.4 ...............---..
NOTE----------------.......
In MODE 4, only the manual portion of the actuation signal is required.Verify each containment spray pump starts 24 months automatically on an actual or simulated actuation signal.SR 3.6.6.5 Verify each spray nozzle is unobstructed.
Following maintenance that could result in nozzle blockage SR 3.6.6.6 Verify containment spray locations susceptible to 31 days gas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1 3.6.6-2 CookNucearPlat Unt 13.66-2Amendment No. 28-7, 314 RHR and Coolant Circulation
-High Water Level 3.9.4 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME A.4 Close equipment hatch and 4 hours secure with four bolts.AND A.5 Close one door in each air 4 hours lock.AND A.6 Verify each penetration 4 hours providing direct access from the containment atmosphere to the outside atmosphere is either closed with a manual or automatic isolation valve, blind flange, or equivalent, or is capable of being closed by an OPERABLE Containment Purge Supply and Exhaust System.SURVEILLANCE REQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.9.4.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.4.2 Verify required RHR loop locations susceptible to 31 days.qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1 ..- mnmn o 8 3.9.4-2 Amendment No. 287 RHR and Coolant Circulation
-Low Water Level 3.9.5 SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.9.5.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.5.2------------NOTE-
-------Not required to be performed until 24 hours after a required RHR pump is not in operation.
Verify correct breaker alignment and indicated 7 days power available to the required RHR pump that is not in operation.
SR 3.9.5.3 Verify RHR loop locations susceptible to ,qas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 1395-AmnetNo28 3.9.5-3 Amendment No. 287 Enclosure 4 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 2 TECHNICAL SPECIFICATION PAGES MARKED TO SHOW PROPOSED CHANGES RCS Loops -MODE 4 3.4.6 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. Two required loops B.1 Suspend operations that Immediately inoperable, would cause introduction of coolant into the RCS with OR boron concentration less than required to meet the Required loop not in requirements of LCO 3.1.1.operation.
AND B.2 Initiate action to restore one Immediately loop to OPERABLE status and operation.
SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.6.1 Verify required RHR or RCS loop is in operation.
12 hours SR 3.4.6.2 Verify SG secondary side water levels are above the 12 hours lower tap of the SG wide range level instrumentation by > 418.77 inches for required RCS loops.SR 3.4.6.3 ----NOTE--------
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required pump.SR 3.4.6.4 NOTE..............
....NOT Not required to be performed until 12 hours after enteringq Mode 4.Verify required RHR loop locations susceptible to 31 days ,qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 23462AmnetNo29 3.4.6-2 Amendment No. 269 RCS Loops -MODE 5, Loops Filled 3.4.7 SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.4.7.1 Verify required RHR loop is in operation.
12 hours SR 3.4.7.2 Verify SG secondary side water level is above the 12 hours lower tap of the SG wide range level instrumentation by > 418.77 inches in required SGs.SR 3.4.7.3------------NOTE--...............
Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.7.4 Verify required RHR loop locations susceptible to 31 days.qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 234.3AmnetNo26 3.4.7-3 Amendment No. 269 RCS Loops -MODE 5, Loops Not Filled 3.4.8 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME B. No required RHR loop B.1 Suspend operations that Immediately OPERABLE.
would cause introduction of coolant into the RCS with OR boron concentration less than required to meet Required RHR loop not requirements of LCO 3.1.1.in operation.
AND B.2 Initiate action to restore one Immediately RHR loop to OPERABLE status and operation.
SURVEILLANCE REQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.4.8.1 Verify required RHR loop is in operation.
12 hours SR 3.4.8.2-------------NOTE-
--- --Not required to be performed until 24 hours after a required pump is not in operation.
Verify correct breaker alignment and indicated 7 days power are available to each required RHR pump.SR 3.4.8.3 Verify RHR loop locations susceptible to ,qas accumulation are sufficiently filled with water.31 days Cook Nuclear Plant Unit 23482AmnetNo26 3.4.8-2 Amendment No. 269 ECCS -Operating 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify the following valves are in the listed position with power to the valve operator removed.12 hours Number 2-1MO-261 2-I1MO-262 2-1MO-263 2-I1MO-31 5 2-I1MO-325 2-I1MO-390 2-1CM-305 2-1CM-306 Position Open Open Open Closed Closed Open Closed Closed Function SI suction line Mini flow line Mini flow line Low head SI to hot leg Low head SI to hot leg RWST to RHR Sump line Sump line SR 3.5.2.2-----------------..........NOTE----------31 days Not required to be met for system vent flow paths opened under administrative control.____________Verify each ECCS manual, power operated, and automatic valve in the flow path, that is not locked, sealed, or otherwise secured in position, is in the correct position.SR 3.5.2.3 Verify each ECCS pump's developed head at the In accordance test flow point is greater than or equal to the with the Inservice required developed head. Testing Program SR 3.5.2.4 Verify each ECCS automatic valve in the flow path 24 months that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.5.2.5 Verify each EGGS pump starts automatically on an 24 months actual or simulated actuation signal.Cook Nuclear Plant Unit 2352-AmnetNo26 3.5.2-2 Amendment No. 269 ECCS -Operating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.5.2.6 Verify, for each ECCS throttle valve listed below, each position stop is in the correct position.24 months Valve Number 2-S1-121 N 2-S1-121 S 2-S1-141 Li 2-S1-141 L2 2-S1-141 L3 2-S1-141 L4 SR 3.5.2.7 Verify, by visual inspection, each ECCS train 24 months containment sump suction inlet is not restricted by debris and the suction inlet trash racks and screens show no evidence of structural distress or abnormal corrosion.
SR 3.5.2.8 Verify ECCS locations susceptible to .gas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2 3523AedetN.2Q 8 3.5.2-3 Amendment No. 269, 282 ECCS -Shutdown 3.5.3 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY-I-SR 3.5.3.1---------------
NOTE----------..-
For SR 3.5.2.2, the SR is modified to allow the valves to not be in the correct position, provided they can be aligned to the correct position.The following SRs are applicable for all equipment required to be OPERABLE: In accordance with applicable SRs SR 3.5.2.2, SR 3.5.2.3, SR 3.5.2.6, a~SR 3.5.2.7, and SR 3.5.2.8 Cook Nuclear Plant Unit 23532AmnetNo26 3.5.3-2 Amendment No. 269 Containment Spray System 3.6.6 3.6 CONTAINMENT SYSTEMS 3.6.6 Containment Spray System LCO 3.6.6 APPLICABILITY:
Two containment spray trains shall be OPERABLE.MODES 1, 2, 3, and 4.ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One containment spray A.1 Restore containment spray 72 hours train inoperable, train to OPERABLE status.B. Required Action and B.1 Be in MODE 3. 6 hours associated Completion Time not met. AND B.2 Be in MODE 5. 84 hours SURVEILLANCEREQUIREMENTS
_______SURVEILLANCE FREQUENCY SR 3.6.6.1---------- -NOTE-------
-31 days Not required to be met for system vent flow paths opened under administrative control._____________Verify each containment spray manual, power operated, and automatic valve in the flow path that is not locked, sealed, or otherwise secured in position is in the correct position.Cook Nuclear Plant Unit 236.-AmnetNo29 3.6.6-1 Amendment No. 269 Containment Spray System 3.6.6 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.6.6.2 Verify each containment spray pump's developed In accordance head at the flow test point is greater than or equal to with the Inservice the required developed head. Testing Program SR 3.6.6.3--------------------NOTE------------
In MODE 4, only the manual portion of the actuation signal is required.Verify each automatic containment spray valve in 24 months the flow path that is not locked, sealed, or otherwise secured in position, actuates to the correct position on an actual or simulated actuation signal.SR 3.6.6.4---------------------NOTE--------------
In MODE 4, only the manual portion of the actuation signal is required.Verify each containment spray pump starts 24 months automatically on an actual or simulated actuation signal.SR 3.6.6.5 Verify each spray nozzle is unobstructed.
Following maintenance that could result in nozzle blockage SR 3.6.6.6 Verify containment spray locations susceptible to 31 days.qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2 3662AedetN.29 9 3.6.6-2 Amendment No. 2-69, 298 RHR and Coolant Circulation
-High Water Level 3.9.4 ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIME A.4 Close equipment hatch and 4 hours secure with four bolts.AND A.5 Close one door in each air 4 hours lock.AND A.6 Verify each penetration 4 hours providing direct access from the containment atmosphere to the outside atmosphere is either closed with a manual or automatic isolation valve, blind flange, or equivalent, or is capable of being closed by an OPERABLE Containment Purge Supply and Exhaust System.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.9.4.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.4.2 Verify required RHR loop locations susceptible to 31 days ,qas accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2394-AmnetNo26 3.9.4-2 Amendment No. 269 RHR and Coolant Circulation
-Low Water Level 3.9.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.9.5.1 Verify one RHR loop is in operation and circulating 12 hours reactor coolant at a flow rate of > 2000 gpm.SR 3.9.5.2---------
-NOTE-- -----Not required to be performed until 24 hours after a required RHR pump is not in operation.
Verify correct breaker alignment and indicated 7 days power available to the required RHR pump that is not in operation.
SR 3.9.5.3 Verify RHR loop locations susceptible to ,qas 31 days accumulation are sufficiently filled with water.Cook Nuclear Plant Unit 2395-AmnetNo26 3.9.5-3 Amendment No. 269 Enclosure 5 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 1 TECHNICAL SPECIFICATION BASES PAGES MARKED TO SHOW PROPOSED CHANGES (FOR INFORMATION ONLY)
RCS Loops -MODE 4 B 3.4.6 BASES LCO (continued)
Utilization of the Note is permitted provided the following conditions are met: a. No operations are permitted that would dilute the RCS boron concentration with coolant with boron concentrations less than required to meet the requirements of LCO 3.1 .1, "SHUTDOWN MARGIN (SDM)," therefore maintaining the margin to criticality.
Boron reduction with coolant at boron concentrations less than required to assure SDM is maintained is prohibited because a uniform concentration distribution throughout the RCS cannot be ensured when in natural circulation; and b. Core outlet temperature is maintained at least 1 0&deg;F below saturation temperature, so that no vapor bubble may form and possibly cause a natural circulation flow obstruction.
Note 2 requires that the secondary side water temperature of each SG be< 50&deg;F above each of the RCS cold leg temperatures or the pressurizer water level be < 62% before the start of an RCP with any RCS cold leg temperature
< 152&deg;F. This restraint is to prevent a low temperature overpressure event due to a thermal transient when an RCP is started.An OPERABLE RCS loop comprises an OPERABLE RCP and an OPERABLE SG, which has the minimum water level specified in SR 3.4.6.2.Similarly for the RHR System, an OPERABLE RHR loop comprises an OPERABLE RHR pump (either the east or west) capable of providing forced flow to an OPERABLE RHR heat exchanger.
RCPs and RHR pumps are OPERABLE if they are capable of being powered and are able to provide forced flow if required.
Management of gas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 4, this LCO ensures forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing.One loop of either RCS or RHR provides sufficient circulation for these purposes.
However, two loops consisting of any combination of RCS and RHR loop~s are required to be OPERABLE to meet single failure considerations.
Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";Cook Nuclear Plant Unit 1 B3.4.6-2 Revision No. 12 RCS Loops -MODE 4 B 3.4.6 BASES ACTIONS (continued)_
minimum SDM maintains acceptable margin to subcritical operations.
The immediate Completion Times reflect the importance of maintaining operation for decay heat removal. The action to restore must be continued until one loop is restored to OPERABLE status and operation.
SURVEILLANCE SR 3.4.6.1 REQUIREMENTS This SR requires verification every 12 hours that the required RCS or RHR loop is in operation and circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. The Frequency of 12 hours is 'sufficient considering other indications and alarms available to the operator in the control room to monitor RCS and RHR loop performance.
SR 3.4.6.2 SR 3.4.6.2 requires verification of SG OPERABILITY.
SG OPERABILITY is verified by ensuring that the secondary side water level is above the lower tap of the SG wide range level instrumentation by > 420 inches. If the SG U-tubes become uncovered, the associated loop may not be capable of providing the heat sink necessary for removal of decay heat.The water level can be verified by either the wide range or the narrow range level instruments.
A narrow range level instrument
> 6% or a wide range level instrument
> 79% ensures the Surveillance Requirement limit is met. The 12 hour Frequency is considered adequate in view of other indications available in the control room to alert the operator to the loss of SG level.SR 3.4.6.3 Verification that each required pump is OPERABLE ensures that an additional RCS or RHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
Cook Nuclear Plant Unit I B 3.4.6-4 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.6-4 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 SR 3.4.6.4 RHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventingq and managing gas intrusion and accumulation is necessary for proper operation of the reguired RHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawingqs, 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operatingq conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental 6onditions, the plant configuration, or personnel safety. For these locations, alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.This SR is modified by a Note that states the SR is not reguired to be performned until-12~hours after anterina MODE 4. In a rapid shutdown.Cook Nuclear Plant Unit 1 B 3.4.6-5 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.6-5 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 there may be insufficient time to verify all susceptible locations prior to enteringq MODE 4.The 31 day Frequency takes into consideration the gqradual nature of gqas accumulation in the RHR System pipingc and the procedural controls gqoverningq system operation.
REFERENCES None.Cook Nuclear Plant Unit I B 3.4.6-6 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.6-6 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES-LCO (continued) is to prevent a low temperature overpressure event due to a thermal transient when an RCP is started.Note 4 provides for an orderly transition from MODE 5 to MODE 4 during a planned heatup by permitting removal of RHR loops from operation when at least one RCS loop is in operation.
This Note provides for the transition to MODE 4 where an RCS loop is permitted to be in operation and replaces the RCS circulation function provided by the RHR loops.RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow. An SG can perform as a heat sink via natural circulation when it has an adequate water level and is OPERABLE.Managqement of .qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with RCS loops filled, this LCO requires forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing. One loop of RHR provides sufficient circulation for these purposes.
However, one additional RHR loop is required to be OPERABLE, or the secondary side water level of at least two SGs is required to be above the lower tap of the SG wide range water level instrumentation by > 420 inches.Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO-3.4.6,"RCS Loops -MODE 4";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS A.1, A.2, B.1 and B.2 If one RHR loop is OPERABLE and either the required SGs do not have secondary side water levels above the lower tap of the SG wide range le~vel instrumentation by > 420 inches or one required RHR-loop is inoperable, redundancy for heat removal is lost. Action must be initiated immediately to restore a second RHR loop to OPERABLE status or to restore the secondary side water levels to within limit for the required SGs. Either Required Action will restore redundant heat removal paths.The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.Cook Nuclear Plant Unit I B 3.4.7-3 Revision No. 12 Cook Nuclear Plant Unit 1 B3.4.7-3 Revision No. 12 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES SURVEILLANCE REQUIREMENTS (continued) verifying proper breaker alignment and power available to each required RHR pump. If secondary side water level is above the lower tap of the SG wide range level instrumentation by > 420 inches in at least two SGs, this Surveillance is not needed. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.7.4 RHR System pipincq and components have the potential to develop voids and pockets of entrained gases. Preventinq and manaciingq ,as intrusion and accumulation is necessary for proper operation of the required RHR loop(s) and may also prevent water hammer, pump cavitation, and pumpincq of noncondensible .qas into the reactor vessel.Selection of RHR System locations susceptible to gqas accumulation is based on a review of system desigqn information, includingq pipingq and instrumentation drawings, isometric drawingqs, plan and elevation drawings, and calculations.
The design review is supplemented by system walk downs to validate the system higqh points and to confirm the location and orientation of important components that can become sources of gas or could otherwise cause gqas to be trapped or difficult to remove duringq system maintenance or restoration.
Susceptible locations depend on plant and system configquration, such as stand-by versus operatingq conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow Cook Nuclear Plant Unit 1 B3475Rvso o B 3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnelsafety.
For these locations, alternative methods (e.g..operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Frequency takes into consideration the gradual nature of gqas accumulation in the RHR System piping and the procedural controls governing system operation.
REFERENCES
: 1. NRC Information Notice 95-35, "Degraded Ability of Steam Generators to Remove Decay Heat by Natural Circulation." Cook Nuclear Plant Unit 1 B 3.4.7-5 Revision No. 0 Cook Nuclear Plant Unit 1 B 3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES LCO (continued)
An OPERABLE RHR loop fs comprised of an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHR heat exchanger.
RHR pumps are OPERABLE if they. are capable of being powered and are able to provide flow if required.
Management of ,qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with loops not filled, this LCO requires core heat removal and coolant circulation by the RHR System.Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES I and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.6, "RCS Loops -MODE 4";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS A.__1 ....If one required RHR loop is inoperable, redundancy for RHR is lost.Action must be initiated to restore a second loop to OPERABLE status.The immediate Completion Time reflects the importance of maintaining the- availability of two paths for heat removal.B.1 and B.2 If no required loop is OPERABLE or the required loop is not in operation, except during conditions permitted by Note 1, all operations involving introduction of coolant into the RCS with boron concentration less than required to meet the requirements of LCO 3.1.1 must be suspended and action must be initiated immediately to restore an RHR loop to OPERABLE status and operation.
The required margin to criticality must not be reduced in this type of operation.
Suspending operations that would cause the introduction, into the RCS, of coolant with boron concentration less than required to meet the requirements of LCO 3.1 .1 is-required to assure continued safe operation.
With coolant added without forced circulation, unmixed coolant could be introduced to the core, however coolant added with boron concentration meeting the minimum SDM maintains acceptable margin to subcritical operations.
The immediate Completion Time reflects the importance of maintaining operation for heat removal. The action to restore must continue until one loop is restored to OPERABLE status and operation.
Cook Nuclear Plant Unit 1 B3.4.8-2 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE SR 3.4.8.1 REQUIREMENTS This SR requires verification every 12 hours that the required loop is in operation circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. The Frequency of 12 hours is sufficient considering other indications and alarms available to the operator in the control room to monitor RHR loop performance.
SR 3.4.8.2 Verification that each required pump is OPERABLE ensures that an additional pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.8.3 RHR System pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventinq and managingq gas intrusion and accumulation is necessary for proper operation of the RHR loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to gqas accumulation is based on a review of system design information, includingq piping and instrumentation drawings, isometric drawings, plan and elevation drawings, and calculations.
The desigqn review is supplemented by system walk downs to validate the system higqh points and to confirm the location and orientation of important components that can become sources of gqas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated glas at one or more susceptible locations exceeds an Cook Nuclear Plant Unit 1 B3483Rvso o B3.4.8-3 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gqas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configquration, or personnel safety. For these locations alternative methods (e.gq., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.'
The 31 day Freguency takes into consideration the gqradual nature of gqas accumulation in the RHR System pipingq and the procedural controls gqoverning system operation.
REFERENCES None.Cook Nuclear Plant Unit 1 B 3.4.8-4 Revision No. 0 Cook Nuclear Plant Unit 1 B3.4.8-4 Revision No. 0 ECCS -Operating B 3.5.2 BASES LCO (continued)
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to supply its flow to the RCS hot and cold legs. Management of cias voids is important to ECCS OPERABILITY.
The flow path for each ECCS train must maintain its designed independence to ensure that no single failure can disable both ECCS trains.APPLICABILITY In MODES 1, 2, and 3, the ECCS OPERABILITY requirements for the limiting Design Basis Accident, a large break LOCA, are based on full power operation.
Although reduced power would not require the same level of performance, the accident analysis does not provide for reduced cooling requirements in the lower MODES. MODE 2 and MODE 3 requirements are bounded by the MODE 1 analysis.This LCO is only applicable in MODE 3 and above. Below MODE 3, the SI signal setpoint is allowed to be manually bypassed by operator control, and system functional requirements are relaxed as described in LCO 3.5.3, "ECCS -Shutdown." In MODES 5 and 6, unit conditions are such that the probability of an event requiring ECCS injection is extremely low.ACTIONS A. 1 With one or more ECGS trains inoperable and at least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available, the inoperable components must be returned to OPERABLE status within 72 hours. The 72 hour Completion Time is based on an NRC reliability evaluation (Ref. 8) and is a reasonable time for repair of many ECCS components.
An ECCS train is inoperable if it is not capable of delivering minimum required flow to the RCS. Individual components are inoperable if they are not capable of performing their design function or supporting systems are not available.
The LCO requires the OPERABILITY of a number of independent subsystems.
Due to the redundancy of ECCS trains and the diversity of subsystems, the inoperability of one active component in an ECCS train does not render the ECCS incapable of performing its function.
Neither does the inoperability of two different components, each in a different ECCS train, necessarily result in a loss of function for the ECCS. This Cook Nuclear Plant Unit 1 ..- eiinN.2 B 3.5.2-5 Revision No. 24 ECCS -Operating B 3.5.2 BASES ACTIONS (continued)
C.1 Condition A is applicable with one or more ECCS trains inoperable.
The allowed Completion Time of Required Action A.1 is based on the assumption that at least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train is available.
An inoperable RHR or SI pump concurrent with a closed cross-tie valve in the affected system will result in less than 100% o'f the ECCS flow equivalent to a single OPERABLE ECCS train because there will be flow to only two RCS loops. With less than 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available, the facility is in a condition outside of the accident analyses.
Therefore, LCO 3.0.3 must be entered immediately.
SURVEILLANCE SR 3.5.2.1 REQUIREMENTS Verification of proper valve position ensures that the flow path from the ECCS pumps to the RCS is maintained.
Misalignment of these valves could render both ECCS trains inoperable.
Securing these valves in position by locking out control power ensures that they cannot change position as a result of an active failure or be inadvertently misaligned.-These valves are of the type, described in Reference 9, that can disable the function of both ECCS trains and invalidate the accident analyses.
A 12 hour Frequency is considered reasonable in view of other administrative controls that will ensure a mispositioned valve is unlikely.SR 3.5.2.2 Verifying the correct alignment for manual, power operated, and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since these were verified to be in the correct position prior to locking, sealing, or securing.
This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation.
Rather, it involves verification that those valves capable of being mispositioned are in the correct position.
The 31 day Frequency is appropriate because the*valves are operated under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating experience.
Cook Nuclear Plant Unit 1B352-ReionN.4 B 3.5.2-7 Revision No. 24 ECCS -Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued)
The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationing a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.5.2.3 Verifying that each ECCS pump's developed head at the flow test point is greater than or equal to the required developed head ensures that ECCS pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of ECCS pump performance required by the ASME OM Code (Ref. 10). Since the ECCS pumps cannot be tested with flow through the normal ECCS flow paths, they are tested on recirculation flow (RHR and SI pumps) or normal charging flow path (centrifugal charging pumps). This test confirms one point on the pump design curve and is indicative of overall performance.
Such inservice tests confirm component OPERABILITY and detect incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.5.2.4 and SR 3.5.2.5 These Surveillances demonstrate that each automatic ECCS valve actuates to the required position on an actual or simulated SI signal and that each ECCS pump starts on receipt of an actual or simulated SI signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for unplanned unit transients if the Surveillances were performed with the reactor at power. The 24 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment.
SR 3.5.2.6 Proper throttle valve position is necessary for proper ECCS performance.
These valves have stops to allow proper positioning for restricted flow to a ruptured cold leg, ensuring that the other cold legs receive at least the required minimum flow. This Surveillance verifies the mechanical stop of each listed ECCS throttle valve is in the correct position.
The 24 month Frequency is based on the same reasons as those stated in SR 3.5.2.4 and SR 3.5.2.5.Cook Nuclear Plant Unit 1 B 3.5.2-8 Revision No. 24 ECCS -Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.5.2.7 Periodic inspections of the containment sump suction inlets ensure that they are unrestricted and stay in proper operating condition.
This Surveillance verifies that the sump suction inlets are not restricted by debris and the suction inlet strainers show no evidence of structural
" distress, such as openings or gaps, which would allow debris to bypass the strainers.
The 24 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a unit outage, on the need to have access to the location.
This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience.
SR 3.5.2.8 EGCS pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventing and managling gas intrusion and accumulation is necessary for proper operation of the EGOS and may also prevent water hammer, pump cavitation, and pumping of noncondensible .qas into the reactor vessel.Selection of EGGS locations susceptible to ,qas accumulation is based on a review of system design information, includingq 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 higqh points and to confirm the location and orientation of important components that can become sources of ,qas or could otherwise cause gas to be trapped or difficult to remove duringq system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The EGOS is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suction or discharge of a pump), the S.urveillance is not met. If it is determined by subseguent evaluation that the EGOS is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brougqht within the acceptance criteria limits.EGOS locations susceptible to ,qas accumulation are monitored and, if.gas is found, the gas volume is compared to the acceptance criteria for Cook Nuclear Plant Unit 1B352-ReionN.4 B 3.5.2-9 Revision No. 24 EGOS -Operating B 3.5.2 the location.
Susceptible locations in the same system flow path which are subject to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety.For these locations, alternative methods (e.gq., operating parameters, remote monitoring) may be used to monitor the susceptible location.Monitoring is not required for susceptible locations where the maximum potential accumulated ,qas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Frequency takes into consideration the gqradual nature of gas accumulation in the ECCS piping and the procedural controls governing system operation.
REFERENCES
: 1. UFSAR, Section 1.4.7.2. 10 CFR 50.46.3. UFSAR, Section 14.3.1.4. UFSAR, Section 14.3.2.5. UFSAR, Section 14.2.4.6. UFSAR, Section 14.2.5.7. UFSAR, Section 14.3.4.8. NRC Memorandum to V. Stello, Jr., from R.L. Baer, "Recommended Interim Revisions to LCOs for ECCS Components," December 1, 1975.9. IE Information Notice No. 87-01 10. ASME, Operations and Maintenance Standards and Guides (OM Codes).Cook Nuclear Plant Unit 1 B 3.5.2-9 Revision No. 24 Cook Nuclear Plant Unit 1 B 3.5.2-9 Revision No. 24 ECCS -Shutdown B 3.5.3 BASES LCO (continued)
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold ,leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to deliver its flow to the RCS hot and cold legs. Managqement of ,qas voids is important to ECOS OPERABILITY.
APPLICABILITY In MODES 1, 2, and 3, the OPERABILITY requirements for ECCS are covered by LCO 3.5.2.In MODE 4 with RCS temperature below 350&deg;F, one OPERABLE ECCS train is acceptable without single failure consideration, on the basis of the stable reactivity of the reactor and the limited core cooling requirements.
In MODES 5 and 6, unit conditions are such that the probability of an event requiring ECCS injection is extremely low.ACTIONS .A Note prohibits the application of LCO 3.0.4.b to an inoperable ECCS centrifugal charging subsystem when entering MODE 4. There is an increased risk associated with entering MODE 4 from MODE 5 with an inoperable ECCS centrifugal charging subsystem and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.
A.1 With no ECCS RHR subsystem OPERABLE, the unit is not prepared to respond to a loss of coolant accident or to continue a cooldown using the RHR pumps and heat exchangers.
The Completion Time of immediately to initiate actions that would restore at least one ECCS RHR subsystem to OPERABLE status ensures that prompt action is taken to restore the required cooling capacity.With both RHR subsystems inoperable, it would be unwise to require the plant to go to MODE 5, where the only available heat removal system is the RHR. Therefore, the appropriate action is to initiate measures to restore one ECCS RHR subsystem and to continue the actions until the subsystem is restored to OPERABLE status.Cook Nuclear Plant Unit 1 B3.5.3-2 Revision No. 0 Containment Spray System B 3.6.6 BASES APPLI CABLE SAFETY ANALYSES (continued)
ECCS cooling effectiveness during the core reflood phase of a LOCA analysis increases with increasing containment backpressure.
For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures in accordance with 10 CFR 50, Appendix K (Ref. 4).The Containment Spray System satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO LCO During a DBA, one train of Containment Spray System is required to provide the heat removal capability assumed in the safety analyses.Additionally, a minimum of one train of the Containment Spray System, with spray pH adjusted by the Spray Additive System, is required to scavenge iodine fission products from the containment atmosphere and ensure their retention in the containment sump water. To ensure that these requirements are met, two containment spray trains must be OPERABLE with power from two safety related, independent power supplies.
Therefore, in the event of an accident, at least one train in each system operates.Each containment spray train includes a spray pump, headers, valves, heat exchangers, nozzles, piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an ESF actuation signal. Managqement of ,qas voids is important to Containment Spray System OPERABILITY.
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment and an increase in containment pressure and temperature requiring the operation of the Containment Spray System.In MODES 5 and 6, the probability and consequences of these events are reduced because of the pressure and temperature limitations of these MODES. Thus, the Containment Spray System is not required to be OPERABLE in MODE 5 or 6.ACTIONS A. 1 With one containment spray train inoperable, the affected train must be restored to OPERABLE status within 72 hours. The components in this degraded condition are capable of providing 100% of the heat removal and iodine removal needs after an accident.
The 72 hour Completion Time was developed taking into account the redundant heat removal and iodine removal capabilities afforded by the OPERABLE train and the low probability of a DBA occurring during this period.Cook Nuclear Plant Unit 1 ..- eiinN.3 B 3.6.6-4 Re-vision No. 36 Containment Spray System B 3.6.6 BASES ACTIONS (continued)
B.1 and B.2 If the affected containment spray train cannot be restored to OPERABLE status within the required Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours and to MODE 5 within 84 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.The extended interval to reach MODE 5 allows additional time and is reasonable when considering that the driving force for a release of radioactive material from the Reactor Coolant System is reduced in MODE 3.SURVEILLANCE SR 3.6.6.1 REQUIREMENTS Verifying the correct alignment of manual, power operated, and automatic valves, excluding check valves, in the Containment Spray System provides assurance that the proper flow path exists for Containment Spray System operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position since they were verified in the correct position prior to being secured. This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. This SR does not require any testing or valve manipulation.
Rather, it involves verification that those valves outside containment and capable of potentially being mispositioned, are in the correct position.The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationinq a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.6.6.2 Verifying that each containment spray pump's developed head at the flow test point is greater than or equal to the required developed head ensures that spray pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of centrifugal pump performance required by the ASME OM Code (Ref. 5).Since the containment spray pumps cannot be tested with flow through the spray headers, they are tested on bypass flow. This test confirms one point on the pump design curve and is indicative of overall performance.
Cook Nuclear Plant Unit 1B366-ReionN.2 B 3.6.6-5 Revision No. 32 Containment Spray System B 3.6.6 BASES SURVEILLANCE REQUIREMENTS (continued)
Such inservice tests confirm component OPERABILITY and detect incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.6.6.3 and SR 3.6.6.4 These SRs require verification that each automatic containment spray valve actuates to its correct position and each containment spray pump starts upon receipt of an actual or Simulated containment spray actuation signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for an unplanned transient if the Surveillances were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillances when performed at the 24 month Frequency.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
These Surveillances include a Note that states that in MODE 4, only the manual portion of the actuation signal is required.
This is acceptable since the automatic portion of the actuation signal is not required to be OPERABLE by ITS 3.3.2, "Engineered Safety Features Actuation System (ESFAS) Instrumentation." SR 3.6.6.5 With the containment spray inlet valves closed and the spray header drained of any solution, low pressure air or smoke can be blown through test connections.
This SR ensures that each spray nozzle is unobstructed and that spray coverage of the containment during an accident is not'degraded.
Because of the passive design of the nozzle, a test at 10 year intervals is considered adequate to detect obstruction of the spray nozzles.SR 3.6.6.6 Containment Spray System pipingq and components have the potential to develop voids and pockets of entrained gases. Preventing and managqingq gqas intrusion and accumulation is necessary for proper operation of the containment spray trains and may also prevent water hammer and pump cavitation.
Selection of Containment Spray System locations susceptible to gqas accumulation is based on a review of system desigqn information, including piping and instrumentation drawings, isometric drawings, plan Cook Nuclear Plant Unit 1 B 3.6.6-6 Revision No. 32 Containment Spray System B 3.6.6 and elevation drawinqs, 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The Containment Spray System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or dischargqe of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the Containment Spray System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met.Accumulated gqas should be eliminated or brought within the acceptance criteria limits.Containment Spray System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations, alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gas accumulation in the Containment Spray System pipingq and the procedural controls governing system operation.
REFERENCES
: 1. UFSAR, Section 1.4.7.2. UFSAR, Section 14.3.4.3. 10 CFR 50.49.4. 10 CFR 50, Appendix K.5. ASME, Operation and Maintenance Standards and Guides (OM Codes).Cook Nuclear Plant Unit 1 B3.6.6-6 Revision No. 32 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES LCO (continued)
An OPERABLE RHR loop includes an RHR pump, a heat exchanger, valves, piping, instruments, and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Manaciement of .qas voids is important to RHR System OPERABILITY.
The LCO is modified by a Note that allows the required operating RHR loop to be removed from operation for up to 1 hour per 8 hour period, provided no operations are permitted that would dilute the RCS boron concentration by introduction of coolant into the RCS with boron concentration less than required to meet the minimum boron concentration of LCO 3.9.1, "Boron Concentration." Boron concentration reduction with coolant at boron concentrations less than required to assure the RCS boron concentration is maintained is prohibited because uniform concentration distribution cannot be ensured without forced circulation.
This permits operations such as core mapping or alterations in the vicinity of the reactor vessel hot leg nozzles and RCS to RHR isolation valve testing. During this 1 hour period, decay heat is removed by natural convection to the large mass of water in the refueling cavity.APPLICABILITY One RHR loop must be OPERABLE and in operation in MODE 6, with the water level > 23 ft above the top of the reactor vessel flange, to provide decay heat removal. The 23 ft water level was selected because it corresponds to the 23 ft requirement established for fuel movement in LCO 3.9.6, "Refueling Cavity Water Level." Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level < 23 ft are located in LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." RHR loop requirements are met by having one RHR loop OPERABLE ACTIONS and in operation, except as permitted in the Note to the LCO.A.1 If RHR loop requirements are not met, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit I B 3.9.4-2 Revision No. 0* Cook Nuclear Plant Unit 1 B3.9.4-2 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES SURVEILLANCE SR 3.9.4.1 REQUIREMENTS This Surveillance demonstrates that the RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. The Frequency of 12 hours is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the RHR System.SR 3.9.4.2 RHR 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 loops and may also preyent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR 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 gqas or could otherwise cause gas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus.operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location ('or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gas ('i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subiect to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radioloaical or environmental conditions, the plant confiauration, or Cook Nuclear Plant Unit 1 B 3.9.4-4 Revision No. 0 Cook Nuclear Plant Unit 1 B3.9.4-4 Revision No. 0 k.RHR and Coolant Circulation
-High Water Level B 3.9.4.personnel safety. For these locations alternative methods ('e.gq., operatingq parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy oT the method used for monitoring the susceptible locations and trendinq of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gqradual nature of gqas accumulation in the RHR System pipingq and the procedural controls gqoverningq system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 1 B3944Rvso o B3.9.4-4 Revision No. 0 RHR and Coolant Circulation
-Low Water Level B 3.9.5 BASES LCO (continued)
This LCO is modified by a Note that allows one RHR loop to be inoperable for a period of 2 hours provided the other loop is OPERABLE and in operation.
Prior to declaring the loop inoperable, consideration should be given to the existing plant configuration.
This consideration should include time to core boiling, potential for RCS draindown, and RCS makeup capability.
This permits surveillance tests to be performed on the inoperable loop during a time when these tests are safe and possible.An OPERABLE RHR loop consists of an RHR pump, a heat exchanger, valves, piping, instruments and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Managqement of .qas voids is important to RHR System OPERABILITY.
APPLICABILITY Two RHR loops are required to be OPERABLE, and one RHR loop must be in operation in MODE 6, with the water level < 23 ft above the top of the reactor vessel flange, to provide decay heat removal. Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level > 23 ft are located in LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level." ACTIONS A.1 and A.2 If less than the required number of RHR loops are OPERABLE, action shall be immediately initiated and continued until the RHR loop is restored to OPERABLE status and to operation or until > 23 ft of water level is established above the reactor vessel flange. When the water level is-- 23 ft above the reactor vessel flange, the Applicability changes to that of LCO 3.9.4, and only one RHR loop is required to be OPERABLE and in operation.
An immediate Completion Time is necessary for an operator to initiate corrective actions.B. 1 If no RHR loop is in operation, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit 1 B3952Rvso o B3.9.5-2 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.5 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.9.5.2 Verification that the required pump is OPERABLE ensures that an additional RHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to the required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
SR 3.9.5.3 RHR System pipingq and components have the potential to develop voids and pockets of entrained gases. Preventing and managqing gqas intrusion and accumulation is necessary for proper operation of the RHR loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to ,qas accumulation is based on a review of system design information, includingq piping and instrumentation drawings, isometric drawingqs, plan and elevation drawingqs, and calculations.
The desigqn 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 gqas or could otherwise cause gqas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suctio'n or discharge of a pump), the Surveillance is not met. If it is determined by subsequent evaluation that the RHR System is not rendered inoperable by the accumulated gqas ('i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance cook Nuclear Plant Unit 1 B3.9.5-4 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.5 criteria for the location.
Susceptible locations in the same system flow path which are subject to the same ,qas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods (e.g., operatingq parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoringq the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gas accumulation in the RHR System piping and the procedural controls gqoverning system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 1 ..- evso o B3.9.5-4 Revision No. 0 Enclosure 6 to AEP-NRC-2016-07 DONALD C. COOK NUCLEAR PLANT UNIT 2 TECHNICAL SPECIFICATION BASES PAGES MARKED TO SHOW PROPOSED CHANGES (FOR INFORMATION ONLY)
RCS Loops -MODE 4 B 3.4.6 BAS ES LCO (continued)
Utilization of the Note is permitted provided the following conditions are met: a. No operations are permitted that would dilute the RCS boron concentration with coolant with boron concentrations less than required to meet the requirements of LCO 3.1.1, "SHUTDOWN MARGIN (SDM)," therefore maintaining the margin to criticality.
Boron reduction with coolant at boron concentrations less than required to assure SDM is maintained is prohibited because a uniform concentration distribution throughout the RCS cannot be ensured when in natural circulation; and b. Core outlet temperature is maintained at least 10&deg;F below saturation temperature, so that no vapor bubble may form and possibly cause a natural circulation flow obstruction.
Note 2 requires that the secondary side water temperature of each SG be< 50&deg;F above each of the RCS cold leg temperatures or the pressurizer water level be < 62% before the start of an RCP with any RCS cold leg temperature
< 1 52&deg;F. This restraint is to prevent a low temperature overpressure event due to a thermal transient when an RCP is started.An OPERABLE RCS loop comprises an OPERABLE RCP and an OPERABLE SG, which has the minimum water level specified in SR 3.4.6.2.Similarly for the RHR System, an OPERABLE RHR loop comprises an OPERABLE RHR pump (either the east or west) capable of providing forced flow to an OPERABLE RHR heat exchanger.
RCPs and RHR pumps are OPERABLE if they are capable of being powered and are able to provide forced flow if required.
Management of .gas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 4, this LCO ensures forced circulation of the reactor coolant to.remove decay heat from the core and to provide proper boron mixing.One loop of either RCS or RHR provides sufficient circulation for these However, two loops consisting of any combination of RCS and RHR loops are required to be OPERABLE to meet single failure considerations.
Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";Cook Nuclear Plant Unit 2 B 3.4.6-2 Revision No. 12 RCS Loops -MODE 4 B 3.4.6 BASES ACTIONS (continued) minimum SDM maintains acceptable margin to subcritical operations.
The immediate Complet~ion Times reflect the importance of maintaining operation for decay heat removal. The action to restore must be continued until one loop is restored to OPERABLE status and operation.
SURVEILLANCE SR 3.4.6.1 REQUIREMENTS This SR requires verification every 12 hours that the required RCS or RHR loop is in operation and circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. -The Frequency of 12 hours is sufficient considering other indications and alarms avtailable to the operator in the control room to monitor RCS and RHR loop performance.
SR 3.4.6.2 SR 3.4.6.2 requires verification of SG OPERABILITY.
SG OPERABILITY is verified by ensuring that the secondary side water level is above the lower tap of the SG wide range level instrumentation by >- 418.77 inches.If the SG U-tubes become uncovered, the associated loop may not be capable of providing the heat sink necessary for removal of decay heat.The water level can be verified by either the wide range or the narrow range level instruments.
A narrow range level instrument
> 6% or a wide range level instrument
> 79% ensures the Surveillance Requirement limit is met. The 12 hour Frequency is considered adequate in view of other indications available in the control room to alert the operator to the loss of SG level.SR 3.4.6.3 Verification that each required pump is OPERABLE ensures that an additional RCS or RHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are-ensured if a pump is operating.
Cook Nuclear Plant Unit 2 B 3.4.6-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.6-4 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 SR 3.4.6.4 RHR System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managingl gas intrusion and accumulation is necessary for proper operation of the required RHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subsequent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e.. the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations, alternative methods (e.g., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the suscePtible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.This SR is modified by a Note that states the SR is not required to be performed until 12 hours after entering MODE 4. In a rapid shutdown.Cook Nuclear Plant Unit 2 B 3.4.6-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.6-4 Revision No. 0 RCS Loops -MODE 4 B 3.4.6 there may be insufficient time to verify all susceptible locations prior to enterinq MODE 4.The 31 day Frequency takes into consideration the gradual nature of gas accumulation in the RHR System piping and the procedural controls gloverning system operation.
REFERENCES None.Cook Nuclear Plant Unit 2 B 3.4.6-5 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.6-5 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES LCO (continued) is to prevent a low temperature overpressure event due to a thermal transient when an RCP is Started.Note 4 provides for an orderly transition from MODE 5 to MODE 4 during a planned heatup by permitting removal of RHR loops from operation when at least one RCS loop is in operation.
This Note provides for the transition to MODE 4 where an RCS loop is permitted to be in operation and replaces the RCS circulation function provided by the RHR loops.RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow. An SG can perform as a heat sink via natural circulation when it has an adequate water level and is OPERABLE.Manaqement of qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with RCS loops filled, this LCO requires forced circulation of the reactor coolant to remove decay heat from the core and to provide proper boron mixing. One loop of RHR provides sufficient circulation for these purposes.
However, one additional RHR loop is required to be OPERABLE, or the secondary side water level of at least two SGs is required to be above the lower tap of the SG wide range water level instrumentation by > 418.77 inches.Operation in Other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.6, "RCS Loops -MODE 4";LCO 3.4.8, "RCS Loops -MODE 5, Loops Not Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS A.1, A.2. B.1 and B.2 If one RHR loop is OPERABLE and either the required SGs do not have secondary side water levels above the lower tap of the SG wide range level instrumentation by > 418.77 inches or one required RHR loop is inoperable, redundancy for heat removal is lost. Action must be initiated immediately to restore a second RHR loop to OPERABLE status or to restore the secondary side water levels to within limit for the required SGs. Either Required Action will restore redundant heat removal paths.The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.Cook Nuclear Plant Unit 2B3473ReionN.1 B3.4.7-3 Revision No. 12 RCS Loops -MODE 5, Loops Filled B 3.4.7 BASES SURVEILLANCE REQUIREMENTS (continued) verifying proper breaker alignment and power available to each required RHR pump. If secondary side water level is above the lower tap of the SG wide range level instrumentation by -> 418.77 inches in at least two SGs, this Surveillance is not needed. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.7.4 RHR 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 required RHR loop(s) and may also prevent water hammer, pump cavitation, and pumping of noncondensible gas into the reactor vessel.Selection of RHR 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Suscentible locations in the same system flow Cook Nuclear Plant Unit 2 B 3.4.7-5 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Filled B 3.4.7 path which are subiect to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods (e.gq., operatingq parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitorinq is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoringq the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gqradual nature of gas accumulation in the RHR System piping and the procedural controls gqoverning system operation.
REFERENCES
: 1. NRC Information Notice 95-35, "Degraded Ability of Steam Generators to Remove Decay Heat by Natural Circulation." Cook Nuclear Plant Unit 2 B 3.4.7-5 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.7-5 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES LCO (continued)
An OPERABLE RHR loop is comprised of an OPERABLE RHR pump capable of providing forced flow to an OPERABLE RHR heat exchanger.
RHR pumps are OPERABLE if they are capable of being powered and are able to provide flow if required.
Managqement of ,qas voids is important to RHR System OPERABILITY.
APPLICABILITY In MODE 5 with loops not filled, this LCO requires core heat removal and coolant circulation by the RHR System.Operation in other MODES is covered by: LCO 3.4.4, "RCS Loops -MODES 1 and 2";LCO 3.4.5, "RCS Loops -MODE 3";LCO 3.4.6, "RCS Loops -MODE 4";LCO 3.4.7, "RCS Loops -MODE 5, Loops Filled";LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level"; and LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation--
Low Water Level." ACTIONS A.1 If one required RHR loop is inoperable, redundancy for RHR is lost.Action must be initiated to restore a second loop to OPERABLE status.The immediate Completion Time reflects the importance of maintaining the availability of two paths for heat removal.B.1 and B.2 If no required loop is OPERABLE or the required loop is not in operation, except during conditions permitted by Note 1, all operations involving introduction of coolant into the RCS with boron concentration less than required to meet the requirements of LCO 3.1.1 must be suspended and action must be initiated immediately to restore an RHR loop to OPERABLE status and operation.
The required margin to criticality must not be reduced in this type of operation.
Suspending operations that would cause the introduction, into the RCS, of coolant with boron concentration less than required to meet the requirements of LCO 3.1.1 is required to assure continued safe operation.
With coolant added without forced circulation, unmixed coolant could be introduced to the core, however coolant added with boron concentration meeting the minimum SDM maintains acceptable margin to subcritical operations.
The immediate Completion Time reflects the importance of maintaining operation for heat removal. The action to restore must continue until one loop is restored to OPERABLE status and operation.
Cook Nuclear Plant Unit 2 B3482Rvso o B3.4.8-2 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 BASES SURVEILLANCE SIR 3.4.8.1 REQUIREMENTS This SR requires verification every 12 hours that the required loop is in operation circulating reactor coolant. Verification includes flow rate, temperature, or pump status monitoring, which help ensure that forced flow is providing heat removal. The Frequency of 12 hours is sufficient considering other indications and alarms available to the operator in the control room to monitor IRHR loop performance.
SR 3.4.8.2 Verification that each required pump is OPERABLE ensures that an additional pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to each required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
This is acceptable because proper breaker alignment and power availability are ensured if a pump is operating.
SR 3.4.8.3 RHIR 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 loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gqas into the reactor vessel.Selection of IRHR System locations susceptible to gas accumulation is based on a review of system design information, including piping and instrumentation drawings, isometric drawingqs, 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHIR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated glas at one or more susceptible locations exceeds an Cook Nuclear Plant Unit 2 B3483Rvso o B3.4.8-3 Revision No. 0 RCS Loops -MODE 5, Loops Not Filled B 3.4.8 acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subsequent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configquration, or personnel safety. For these locations alternative methods (e.gq., operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Freguency takes into consideration the gqradual nature of gas accumulation in the RHR System pipingq and the procedural controls gqoverningq system operation.
REFERENCES None.Cook Nuclear Plant Unit 2 B 3.4.8-3 Revision No. 0 Cook Nuclear Plant Unit 2 B3.4.8-3 Revision No. 0 ECCS -Operating B 3.5.2 BASES LCO (continued)
During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to supply its flow to the RCS hot and cold legs. Managqement of .qas voids is important to ECCS OPERABILITY.
The flow path for each ECCS train must maintain its designed independence to ensure that no single failure can disable both ECCS trains. -APPLICABILITY In MODES 1, 2, and 3, the ECCS OPERABILITY requirements for the limiting Design Basis Accident, a large break LOCA, are based on full power operation.
Although reduced power would not require the same level of performance, the accident analysis does not provide for reduced cooling requirements in the lower MODES. MODE 2 and MODE 3 requirements are bounded by the MODE I analysis.This LCO is only applicable in MODE 3 and above. Below MODE 3, the SI signal setpoint is allowed to be manually bypassed by operator control, and system functional requirements are relaxed as described in LCO 3.5.3, "ECCS -Shutdown." In MODES 5 and 6, unit conditions are such that the probability of an event requiring ECCS injection is extremely low.ACTIONS A. 1 With one or more ECCS trains inoperable and at least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available, the inoperable components must be returned to OPERABLE status within 72 hours. The 72 hour Completion Time is based on an NRC reliability evaluation (Ref. 8) and is a reasonable time for repair of many ECCS components.
An ECCS train is inoperable if it is not capable of delivering minimum required flow to the RCS. Individual components are inoperable if they are not capable of performing their design function or supporting systems are not available.
The LCO requires the OPERABILITY of a number of independent subsystems.
Due to the redundancy of ECCS trains and the diversity of subsystems, the inoperability of one active component in an ECCS train does not render the ECCS incapable of performing its function.
Neither does the inoperability of two different components, each in a different ECCS train, necessarily result in a loss of function for the ECCS.Cook Nuclear Plant Unit 2B352-ReionN.0 B 3.5.2-5 Revision No. 30 ECCS -Operating B 3.5.2 BASES ACTIONS (continued) train available, the facility is in a condition outside of the accident analyses.
Therefore, LCO 3.0.3 must be entered immediately.
SURVEILLANCE SR 3.5.2.1 REQUIREMENTS Verification of proper valve position ensures that the flow path from the ECCS pumps to the ROS is maintained.
Misalignment of these valves could render both ECCS trains inoperable.
Securing these valves in position by locking out control power ensures that they cannot change position as a result of an active failure or be inadvertently misaligned.
These valves are of the type, described in Reference 9, that can disable the function of both ECCS trains and invalidate the accident analyses.
A 12 hour Frequency is considered reasonable in view of other-administrative controls that will ensure a mispositioned valve is unlikely.SR 3.5.2.2 Verifying the correct alignment for manual, power operated, and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position, since these were verified to be in the correct position prior to locking, sealing, or securing.
This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve will automatically reposition within the proper stroke time. This Surveillance does not require any testing or valve manipulation.
Rather, it involves verification that those valves capable of being mispositioned are in the correct position.
The 31 day Frequency is appropriate because the valves are operated under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating experience.
The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationingq a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.5.2.3 Verifying that each ECCS pump's developed head at the flow test point is greater than or equal to the required developed head ensures that ECCS pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of ECCS pump performance required by the ASME OM Code (Ref. 10). Since the ECCS Cook Nuclear Plant Unit 2 B 3.5.2-7 Revision No. 30 ECCS -Operating B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued) pumps cannot be tested with flow through the normal ECCS flow paths, they are tested on recirculation flow (RHR and SI pumps) or normal charging flow path (centrifugal charging pumps). This test confirms one point on the pump design curve and is indicative of overall performance.
Such inservice tests confirm component OPERABILITY and detect incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.5.2.4 and SR 3.5.2.5 These Surveillances demonstrate that each automatic ECCS valve actuates to the required position on an actual or simulated SI signal and that each ECCS pump starts on receipt of an actual or simulated SI signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for unplanned unit transients if the Surveillances were performed with the reactor at power. The 24 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment.
SR 3.5.2.6 Proper throttle valve position is necessary for proper ECCS performance.
These valves have stops to allow proper positioning for restricted flow to a ruptured cold leg, ensuring that the other cold legs receive at least the required minimum flow. This Surveillance verifies the mechanical stop of each listed ECOS throttle valve is in the correct position.
The 24 month Frequency is based on the same reasons as those stated in SR 3.5.2.4 and SR 3.5.2.5.SR 3.5.2.7 Periodic inspections of the containment sump suction inlets ensure that they are unrestricted and stay in proper operating condition.
This Surveillance verifies that the sump suction inlets are not restricted by debris and the suction inlet strainers show no evidence of structural distress, such as openings or gaps, which would allow debris to bypass the strainers.
The 24 month FrequencY is based on the need to perform this Surveillance under the conditions that apply during a unit outage, on the need to have access to the location.
This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience.
Cook Nuclear Plant Unit 2 B 3.5.2-8 Revision No. 16 Cook Nuclear Plant Unit 2 B3.5.2-8 Revision No. 16 ECCS -Operating B 3.5.2 SR 3.5.2.8 ECCS pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventing and managingq gas intrusion and accumulation is necessary for proper operation of the ECCS and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of ECCS locations susceptible to gqas accumulation is based on a review of system design information, including pipingq and instrumentation drawings, isometric drawingqs, plan and elevation drawingqs, 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 gqas or could otherwise cause gqas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The ECCS is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the ECCS is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.EGOS locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subiect to the same gqas intrusion mechanisms may be verified by monitoringq a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configquration, or personnel safety.For these locations, alternative methods (e.g., operatingq parameters, remote monitoring) may be used to monitor the susceptible location.Monitoringq is not reguired for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gqas accumulation in the ECOS pipingq and the procedural controls gqoverning system operation.
Cook Nuclear Plant Unit 2B352-ReionN.1 B 3.5.2-8 Revision No. 16 ECCS -Operating B 3.5.2 BASES REFERENCES 1.2.3.4.5.6.7.8.UFSAR, Section 1.4.7.10 CFR 50.46.UFSAR, Section 14.3.1.UFSAR, Section 14.3.2.UFSAR, Section 14.2.4.UFSAR, Section 14.2.5.UFSAR, Section 14.3.4.NRC Memorandum to V. Stello, Jr., from R.L. Baer, "Recommended Interim Revisions to LCOs for ECOS Components," December 1, 1975.IE Information Notice No. 87-01.ASME, Operations and Maintenance Standards and Guides (OM Codes).9.10.Cook Nuclear Plant Unit 2 B 3.5.2-9 Revision No. 16 Cook Nuclear Plant Unit 2 B 3.5.2-9 Revision No. 16 EGOS -Shutdown B 3.5.3 BASES LCO (continued)
During an event requiring ECCS actuation, a fiow path is required to provide an abundant supply of water from the RWST to the RCS via the EGGS pumps and their respective supply headers to each of the four cold leg injection nozzles. In the long term, this flow path may be switched to take its supply from the containment sump and to deliver its flow to the RCS hot and cold legs. Managqement of gas voids is important to EGOS OPERABILITY.
APPLICABILITY In MODES 1, 2, and 3, the OPERABILITY requirements for EGOS are covered by LCO 3.5.2.In MODE 4 with RCS temperature below 350&deg;F, one OPERABLE EGGS train is acceptable without single failure consideration, on the basis of the stable reactivity of the reactor and the limited core cooling requirements.
In MODES 5 and 6, unit conditions are such that the probability of an event requiring EGGS injection is extremely low.ACTIONS A Note prohibits the application of LCO 3.O.4.b to an inoperable ECOS centrifugal charging subsystem when entering MODE 4. There is an increased risk associated with entering MODE 4 from MODE 5 with an inoperable EGGS centrifugal charging subsystem and the provisions of LGO 3.O.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.
A.1 With no EGOS RHR subsystem OPERABLE, the unit is not prepared to respond to a loss of coolant accident or to continue a cooldown using the RHR pumps and heat exchangers.
The Completion Time of immediately to initiate actions that would restore at least one EGOS RHR subsystem to OPERABLE status ensures that prompt action is taken to restore the required cooling capacity.With both RHR subsystems inoperable, it would be unwise to require the plant to go to MODE 5, where the only available heat removal system is the RHR. Therefore, the appropriate action is to initiate measures to restore one EGOS RHR subsystem and to continue the actions until the subsystem is restored to OPERABLE status.Cook Nuclear Plant Unit 2 B3532Rvso o B 3.5.3-2 Revision No. 0 Containment Spray System B 3.6.6 BASES APPLI CABLE SAFETY ANALYSES (continued)
ECCS cooling effectiveness during the core reflood phase of a LOCA analysis increases with increasing containment backpressure.
For these calculations, the containment backpressure is calculated in a manner designed to conservatively minimize, rather than maximize, the calculated transient containment pressures in accordance with 10 CFR 50, Appendix K (Ref. 4).The Containment Spray System satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO During a DBA, one train of Containment Spray System is required to provide the heat removal capability assumed in the safety analyses.Additionally, a minimum of one train of the Containment Spray System, with spray pH adjusted by the Spray Additive System, is required to scavenge iodine fission products from the containment atmosphere and ensure their retention in the containment sump water. To ensure that these requirements are met, two containment spray trains must be OPERABLE with power from two safety related, independent power supplies.
Therefore, in the event of an accident, at least one train in each system operates.Each containment spray train includes a spray pump, headers, valves, heat exchangers, nozzles, piping, instruments, and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an ESF actuation signal. Managqement of gas voids is important to Containment Spray System OPERABILITY.
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment and an increase in containment pressure and temperature requiring the operation of the Containment Spray System.In MODES 5 and 6, the probability and consequences of these events are reduced because of the pressure and temperature limitations of these MODES. Thus, the Containment Spray System is not required to be OPERABLE in MODE 5 or 6.ACTIONS A.1 With one containment spray train inoperable, the affected train must be restored to OPERABLE status within 72 hours. The components in this degraded condition are capable of providing 100% of the heat removal and iodine removal needs after an accident.
The 72 hour Completion Time was developed taking into account the redundant heat removal and iodine removal capabilities afforded by the OPERABLE train and the low probability of a DBA occurring during this period.Cook Nuclear Plant Unit 2B3664ReionN.5 B 3.6.6-4 Revision No. 35 Containment Spray System B 3.6.6 BASES ACTIONS (continued)
B.1 and B.2 If the affected containment spray train cannot be restored to OPERABLE status within the required Completion Time, the unit must be brought to a MODE in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE 3 within 6 hours and to MODE 5 within 84 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.The extended interval to reach MODE 5 allows additional time and is reasonable when considering that the driving force for a release of radioactive material from the Reactor Coolant System is reduced in MODE 3.SURVEILLANCE SR 3.6.6.1 REQUIREMENTS Verifying the correct alignment of manual, power operated, and automatic valves, excluding check valves, in the Containment Spray System provides assurance that the proper flow path exists for Containment Spray System operation.
This SR does not apply to valves that are locked, sealed, or otherwise secured in position since they were verified in the correct position prior to being secured. This SR also does not apply to valves that cannot be inadvertently misaligned, such as check valves. This SR does not require any testing or valve manipulation.
Rather, it involves verification that those valves outside containment and capable of potentially being mispositioned, are in the correct position.The Surveillance is modified by a Note which exempts system vent flow paths opened under administrative control. The administrative control should be proceduralized and include stationing a dedicated individual at the system vent flow path who is in continuous communication with the operators in the control room. This individual will have a method to rapidly close the system vent flow path if directed.SR 3.6.6.2 Verifying that each containment spray pump's developed head at the flow test point is greater than or equal to the required developed head ensures that spray pump performance has not degraded to an unacceptable level during the cycle. Flow and differential head are normal tests of centrifugal pump performance required by the ASME OM Code (Ref. 5).Since the containment spray pumps cannot be tested with flow through the spray he'aders, they are tested on bypass flow. This test confirms one point on the pump design curve and is indicative of overall performance.
Such inservice tests confirm component OPERABILITY and detect Cook Nuclear Plant Unit 2B3665ReionN.0 B 3.6.6-5 Revision No. 30 Containment Spray System B 3.6.6 BASES SURVEILLANCE REQUIREMENTS (continued) incipient failures by indicating abnormal performance.
The Frequency of this SR is in accordance with the Inservice Testing Program.SR 3.6.6.3 and SR 3.6.6.4-These SRs require verification that each automatic containment spray valve actuates to its correct position and each containment spray pump starts upon receipt of an actual or simulated containment spray actuation signal. This Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls.
The 24 month Frequency is based on the need to perform these Surveillances under the conditions that apply during a unit outage and the potential for an unplanned transient if the Surveillances were performed with the reactor at power. Operating experience has shown these components usually pass the Surveillances when performed at the 24 month Frequency.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
These Surveillances include a Note that states that in MODE 4, only the manual portion of the actuation signal is required.
This is acceptable since the automatic portion of the actuation signal is not required to be OPERABLE by ITS 3.3.2, "Engineered Safety Features Actuation System (ESFAS) Instrumentation." SR 3.6.6.5 With the containment spray inlet valves closed and the spray header drained of any solution, low pressure air or smoke can be blown through test connections.
This SR ensures that each spray nozzle is unobstructed and that spray coverage of the containment during an accident is not degraded.
Because of the passive design of the nozzle, a test at 10 year intervals is considered adequate to detect obstruction of the spray nozzles.SR 3.6.6.6 Containment Spray System piping and components have the potential to develop voids and pockets of entrained gases. Preventing and managingl gas intrusion and accumulation is necessary for proper operation of the containment spray trains and may also prevent water hammer and pump cavitation.
Selection of Containment Spray System locations susceptible to gqas accumulation is based on a review of system design information, includingq pipingq 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 Cook Nuclear Plant Unit 2B366-ReionN.1 B 3.6.6-6 Revision No. 31 Containment Spray System B 3.6.6 and to confirm the iocation 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The Containment Spray System is OPERABLE when it is sufficiently filled with water. Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gqas at one or more susceptible locations exceeds an acceptance criterion for gqas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the Containment Spray System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met.Accumulated gqas should be eliminated or brought within the acceptance criteria limits.Containment Spray System locations susceptible to gqas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subject to the same gas intrusion mechanisms may be verified by monitoringl a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiologqical or environmental conditions, the plant configquration, or personnel safety. For these locations, alternative methods (e.g.. operating parameters, remote monitoring) may be used to monitor the susceptible location.
Monitoring is not reguired for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenge system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Freguency takes into consideration the gradual nature of gqas accumulation in the Containment Spray System piping and the procedural controls gqoverningq system operation.
REFERENCES
: 1. UFSAR, Section 1.4.7.2. UFSAR, Section 14.3.4.3. 10 CFR 50.49.4. 10 CFR 50, Appendix K.5. ASME, Operation and Maintenance Standards and Guides (OM Codes).Cook Nuclear Plant Unit 2 B3.6.6-6 Revision No. 31 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES LCO (continued)
An OPERABLE RHR loop includes an RHR pump, a heat exchanger, valves, piping, instruments, and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Manaqement of gas voids is important to RHR System OPERABILITY.
The LCO is modified by a Note that allows the required operating RHR loop to be removed from operation for up to 1 hour per 8 hour period, provided no operations are permitted that would dilute the RCS boron concentration by introduction of coolant into the RCS with boron-concentration less than required to meet the minimum boron concentration of LCO 3.9.1, "Boron Concentration." Boron concentration reduction with coolant at boron concentrations less than required to assure the RCS boron concentration is maintained is prohibited because uniform concentration distribution cannot be ensured without forced circulation.
This permits operations such as core mapping or alterations in the vicinity of the reactor vessel hot leg nozzles and RCS to RHR isolation valve testing. During this 1 hour period, decay heat is removed by natural convection to the large mass of water in the refueling cavity.APPLICABILITY One RHR loop must be OPERABLE and in operation in MODE 6, with the water level > 23 ft above the top of the reactor vessel flange, to provide decay heat removal. The 23 ft water level was selected because it corresponds to the 23 ft requirement established for fuel movement in LCO 3.9.6, "Refueling Cavity Water Level." Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level < 23 ft are located in LCO 3.9.5, "Residual Heat Removal (RHR) and Coolant Circulation
-Low Water Level." ACTIONS RHR loop requirements are met by having one RHR loop OPERABLE and in operation, except as permitted in the Note to the LCO.A.1 If RHR loop requirements are not met, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit 2 B3942Rvso o B3.9.4-2 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.4 BASES SURVEILLANCE SR 3.9.4.1 REQUIREMENTS This Surveillance demonstrates that the RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. The Frequency of 12 hours is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the RHR System.SR 3.9.4.2 RHR 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 loops and may also prevent water hammer, pump cavitation, and pumpingq of noncondensible gas into the reactor vessel.Selection of RHR System locations susceptible to gqas accumulation is based on a review of system design information, includingq 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 gqas to be trapped or difficult to remove during system maintenance or restoration.
Susceptible locations depend on plant and system configquration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gqas at susceptible locations.
If accumulated gas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gqas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gas should be eliminated or brought within the acceptance criteria limits.RHR System locations susceptible to gqas accumulation are monitored and, if gqas is found, the gqas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow path which are subiect to the same gas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoringq may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods ('e.g., operating Cook Nuclear Plant Unit 2 B3944Rvso o B3.9.4-4 Revision No. 0 RHR and Coolant Circulation
-High Water Level B 3.9.4 parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitorinq is not required for susceptible locations where the maximum potential accumulated gqas void volume has been evaluated and determined to not challenqe system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY duringq the Surveillance interval.The 31 day Frequency takes into consideration the gradual nature of glas accumulation in the RHR System pipingq and the procedural controls gqoverning system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 2 B 3.9.4-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.4-4 Revision No. 0 RHR and Coolant Circulation
-Low Water Level B 3.9.5 BASES LCO (continued)
This LCO is modified by a Note that allows one RHR loop to be inoperable for a period of 2 hours provided the other loop is OPERABLE and in operation.
Prior to declaring the loop inoperable, consideration should be given to the existing plant configuration.
This consideration should include time to core boiling, potential for RCS draindown, and RCS makeup capability.
This permits surveillance tests to be performed on the inoperable loop during a time when these tests are safe and possible.An OPERABLE RHR loop consists of an RHR pump, a heat exchanger, valves, piping, instruments and controls to ensure an OPERABLE flow path. The flow path starts in one of the RCS hot legs and is returned to at least one of the RCS cold legs. Managqement of ,qas voids is important to RHR System OPERABILITY.
APPLICABILITY Two RHR loops are required to be OPERABLE, and one RHR loop must be in operation in MODE 6, with the water level < 23 ft above the top of the reactor vessel flange, to providedecay heat removal. Requirements for the RHR System in other MODES are covered by LCOs in Section 3.4, "Reactor Coolant System (RCS)." RHR loop requirements in MODE 6 with the water level > 23 ft are located in LCO 3.9.4, "Residual Heat Removal (RHR) and Coolant Circulation
-High Water Level." ACTIONS A.1 and A.2 If less than the required number of RHR loops are OPERABLE, action shall be immediately initiated and continued until the RHR loop is restored to OPERABLE status and to operation or until > 23 ft of water level is established above the reactor vessel flange. When the water level is-> 23 ft above the reactor vessel flange, the Applicability changes to that of LCO 3.9.4, and only one RHR loop is required to be OPERABLE and in operation.
An immediate Completion Time is necessary for an Operator to initiate corrective actions.B. 1 If no RHR loop is in operation, there will be no forced circulation to provide mixing to establish uniform boron concentrations.
Suspending positive reactivity additions that could result in failure to meet the minimum boron concentration limit is required to assure continued safe operation.
Introduction of coolant inventory must be from sources that have a boron concentration greater than that what would be required in the RCS for minimum refueling boron concentration.
This may result in an overall reduction in RCS boron concentration, but provides acceptable margin to maintaining subcritical operation.
Cook Nuclear Plant Unit 2 B 3.9.5-2 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.5-2 Revision No. 0 IRHR and Coolant Circulation
-Low Water Level B 3.9.5 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 3.9.5.2 Verification that the required pump is OPERABLE ensures that an additional IRHR pump can be placed in operation, if needed, to maintain decay heat removal and reactor coolant circulation.
Verification is performed by verifying proper breaker alignment and power available to the required pump. The Frequency of 7 days is considered reasonable in view of other administrative controls available and has been shown to be acceptable by operating experience.
This SIR is modified by a Note that states the SR is not required to be performed until 24 hours after a required pump is not in operation.
SR 3.9.5.3 RHR System pipingq and components have the potential to develop voids and pockets of entrained gqases. Preventing and managingq gas intrusion and accumulation is necessary for proper operation of the IRHR loops and may also prevent water hammer, pump cavitation, and pumpingq of non condensible gas into the reactor vessel.Selection of RHIR 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 bysystem 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.
Susceptible locations depend on plant and system configuration, such as stand-by versus operating conditions.
The RHR System is OPERABLE when it is sufficiently filled with water.Acceptance criteria are established for the volume of accumulated gas at susceptible locations.
If accumulated gqas is discovered that exceeds the acceptance criteria for the susceptible location (or the volume of accumulated gas at one or more susceptible locations exceeds an acceptance criterion for gas volume at the suction or discharge of a pump), the Surveillance is not met. If it is determined by subseguent evaluation that the RHR System is not rendered inoperable by the accumulated gas (i.e., the system is sufficiently filled with water), the Surveillance may be declared met. Accumulated gqas should be eliminated or brought within the acceptance criteria limits.IRHR System locations susceptible to gas accumulation are monitored and, if gas is found, the gas volume is compared to the acceptance criteria for the location.
Susceptible locations in the same system flow Cook Nuclear Plant Unit 2 B 3.9.5-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.5-4 Revision No. 0 RHR and Coolant Circulation
-Low Water Level B 3.9.5 path which are subiect to the same gqas intrusion mechanisms may be verified by monitoring a representative sub-set of susceptible locations.
Monitoring may not be practical for locations that are inaccessible due to radiological or environmental conditions, the plant configuration, or personnel safety. For these locations alternative methods ('e.g., operatinq parameters, remote monitoringq) may be used to monitor the susceptible location.
Monitoring is not required for susceptible locations where the maximum potential accumulated gas void volume has been evaluated and determined to not challengqe system OPERABILITY.
The accuracy of the method used for monitoring the susceptible locations and trending of the results should be sufficient to assure system OPERABILITY during the Surveillance interval.The 31 day Frequency takes into consideration the gqradual nature of gqas accumulation in the RHR System piping and the procedural controls gqoverning system operation.
REFERENCES
: 1. UFSAR, Section 9.3.2.Cook Nuclear Plant Unit 2 B 3.9.5-4 Revision No. 0 Cook Nuclear Plant Unit 2 B3.9.5-4 Revision No. 0}}

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