NOC-AE-06002060, Revision to Proposed Change to Technical Specification 3.3.3.6, Accident Monitoring Instrumentation.

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Revision to Proposed Change to Technical Specification 3.3.3.6, Accident Monitoring Instrumentation.
ML062830032
Person / Time
Site: South Texas  STP Nuclear Operating Company icon.png
Issue date: 10/02/2006
From: Rencurrel D
South Texas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-06002060
Download: ML062830032 (33)
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Text

Nuclear Operating Company South TcIs PoxtElecd c Ganera tlon PO. gar28,9 Mdtsath,Txs 77483 ,A*AA October 2, 2006 NOC-AE-06002060 10CFR50.90 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Revision to Proposed Change to Technical Specification 3.3.3.6, "Accident Monitoring Instrumentation"

Reference:

Letter from T. J. Jordan, STPNOC, to NRC Document Control Desk dated Match 30, 2006, "Proposed Change to Technical Specification 3.3.3.6, 'Accident Monitoring Instrumentation.'

(TAC Nos. MD0934 and MD0935, ML061000283, NOC-AE-05001914)

STP Nuclear Operating Company (STPNOC) submits the attached proposed amendment to South Texas Project Operating Licenses NPF-76 and NPF-80. This license amendment request proposes revising Technical Specification 3.3.3.6, "Accident Monitoring Instrumentation" with respect to the required action for inoperable Wide Range Reactor Coolant Temperature, Wide Range Steam Generator Level, and Auxiliary Feedwater Flow.

STPNOC revised the change proposed in the referenced correspondence to include all four channels of AFW Flow and Wide Range Steam Generator Level in response to NRC staff comments. The proposed changes to Reactor Coolant System Wide Range Temperature have also been revised to include all four channels and the actions more closely aligned with NUREG-1431. The Safety Evaluation also includes more detail with respect to the comparison of the STPNOC proposal to the corresponding functions in NUREG-1431.

There are no commitments in this letter.

STPNOC requests approval of the proposed amendment by February 1, 2007 to allow time for implementation prior to the Unit 2 Spring 2007 refueling outage. If that date cannot be accommodated, STPNOC requests approval after May 1, 2007 so that implementation does not coincide wi:h the Unit 2 outage. STPNOC requests 60 days for implementation of the amendment after it is approved.

The STPNOC Plant Operations Review Committee has reviewed and concurred with the proposed change to the Technical Specifications.

In accordance with 10 CFR 50.91(b), STPNOC is notifying the State of Texas of this request for license amendment by providing a copy of this letter and its attachments. -4ool STI: 32048327

NOC-AE-06002060 Page 2 If there are any questions regarding the proposed amendment, please contact Mr. A. W. Harrison at (361) 972-7298 or me at (361) 972-7867.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on /oLI.f too Date David W. Rencurrel Vice President Engineering

&Strategic Projects Attachments:

1. Description of Changes and Safety Evaluation
2. Annotated Technical Specification Pages
3. Technical Specification Bases Inserts

NOC-AE-06002060 Page 3 cc:

(paper copy) (electronic copy)

Regional Administrator, Region IV A. H. Gutterman, Esquire U. S. Nuclear Regulatory Commission Morgan, Lewis & Bockius LLP 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Mohan C. Thadani U. S. Nuclear Regulatory Commission Senior Resident Inspector Steve Winn U. S. Nuclear Regulatory Commission Christine Jacobs P. 0. Box 289, Mail Code: MN16 Eddy Daniels Wadsworth, TX 77483 NRG South Texas LP C. M. Canady J. J. Nesrsta City of Austin R. K. Temple Electric Utility Department E. Alarcon 721 Barton Springs Road City Public Service Austin, TX 78704 Richard A. Ratliff Jon C. Wood Bureau of Radiation Control Cox Smith Matthews Texas Department of State Health Services 1100 West 49th Street C. Kirksey Austin, TX 78756-3189 City of Austin

NOC-AE-06002060 ATTACHMENT 1 DESCRIPTION OF CHANGES AND SAFETY EVALUATION NOC-AE-06002060 Page 1 1.0 Introduction The proposed amendment will revise Technical Specification (TS) 3.3.3.6, "Accident Monitoring Instrumentation" requirements for the Reactor Coolant Outlet Temperature (Thot - Wide Range), Reactor Coolant Inlet Temperature (Tcold - Wide Range), Steam Generator (SG) Level - Wide Range and Auxiliary Feedwater (AFW) Flow functions.

The proposed changes are based in part on the requirements for these functions in the Westinghouse Improved Standard Technical Specifications (ITS), NUREG-1431. The proposed changes will enhance plant reliability by reducing its exposure to unnecessary shutdowns and increase operational flexibility.

Changes made in this revision to the STPNOC application are identified with a change bar in the margin.

2.0 Description Each of the proposed changes to the Technical Specifications is described in Table I and annotated in Attachment 2.

Table 1 Page Affected Section Description of Change Reason for Change 3/4 3-68 Table 3.3-10 The Total Number of Channels for the Reactor The change is an administrative Coolant Temperature - Wide Range functions is enhancement to clarify that

2. Reactor revised from I/loop to 4 (I/loop) there are four channels since the Coolant Outlet TS action is based on the Temperature - number of operable channels.

TIIoT (Wide Range)

3. Reactor Coolant Inlet Temperature -

TCOLD (Wide Range) 3/4 3-68 Table 3.3-10 The Total Number of Channels for the Steam The change is an administrative Generator Water Level - Wide Range and enhancement to clarify that 8.Steam Generator Auxiliary Feedwater Flow are revised from there are four channels since the Water Level - 1/steam generator to 4 (I/steam generator). TS action is based on the Wide Range The Minimum Channels Operable requirement number of operable channels.

for Steam Generator Water Level - Wide Range F e.Auxiliary is changed from 1/steam generator to 4.

Feedwater Flow The Minimum Channels Operable requirement for Auxiliary Feedwater Flow is changed from 1/steam generator to 4.

NOC-AE-06002060 Page 2 Page Affected Section Description of Change Reason for Change 3/4 3-70 Table 3.3-10 Required ACTION 35 currently states, The 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> allowed outage With the number of OPERABLE channels time of ACTION 35 is

2. Reactor less than the Minimum Channels Operable unnecessarily restrictive for Coolant Outlet lsthnteMnmmCaesOprbe these functions restrictive than and more the requirements TepeatOuret requirement, restore at least one inoperable Temperature - channel to OPERABLE status within 48 establise in treG-rmet T1noT (Wide husorbinalesHOSUT WN established in NUREG-1431 Range) hours, or be in at least HOT SHUTDOWN for these functions. Each affected function has sufficient
3. Reactor The action is revised to extend the allowed redundancy and functional Coolant Inlet outage time to 30 days with one inoperable diversity to justify a less Temperature - channel with a requirement for a Special Report restrictive action.

TCOLD (Wide and a 7-day allowed outage time with a The proposed new ACTION Range) shutdown action for more than one inoperable 35a is based on the channel:

8.Steam Generator requirements in NUREG-1431.

Water Level - a. With the number of OPERABLE The proposed new ACTION Wide Range channels one less than the Minimum 35b is also based on NUREG-Channels Operable requirement, restore the 1431 requirements when all 11.Auxiliary inoperable channel to OPERABLE status channels of a post-accident are Feedwater Flow Flow within within 30the days, next or 14 submit a Specialthe days describing Report inoperable. function monitoring ioeal.Svndy Seven days issaan preplanned alternate method of monitoring, acceptable time based on the the cause of the inoperability, and the plans low probability of an event chanel and scheduleoftheFu ctintOEAL for restoring the instrumentation requiring the furnction and the channels of the Function to OPERABLE availability of backup sources status. for the information needed by

b. With the number of OPERABLE the operators.

channels two or more less than the Minimum Channels Operable requirement, restore at least three channels to OPERABLE status within 7 days, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

3/4 -70 Table 3.3-10 Current requirements in ACTION 38 are deleted No function in Table 3.3-10 in their entirety. references ACTION 38. All ACTION 38 previous references to ACTION 38 were eliminated in Amendments 23/13 in a change unrelated to the two functions proposed for revision in this application; however, the action was never deleted from the Technical Specifications.

Consequently, the deletion of the current requirements of the action is an administrative change.

NOC-AE-06002060 Page 3 3.0 Background STP's design provides one channel of Reactor Coolant Outlet Temperature (Thot - Wide Range) and Reactor Coolant Inlet Temperature (Tco!d - Wide Range) for each Reactor Coolant System (RCS) loop. There is also one channel of Steam Generator Level - Wide Range on each of the four steam generators and one channel of Auxiliary Feedwater (AFW) flow on each of the four trains of AFW. The 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> allowed outage time in the current Technical Specifications is not commensurate with the low safety significance of these instruments.

4.0 Technical Analysis A technical review of each of the proposed changes described in Table I is provided below. The review identifies the affected instrumentation, describes its function, including relevant references to the STP Updated Final Safety Analysis Report (UFSAR).

The discussion of the function of the affected instrumentation is focused on its accident monitoring functions, which are the functions relevant to Technical Specification 3.3.3.6.

Corresponding Bases change inserts are provided in Attachment 3 for the staff's information.

4.1 Reactor Coolant Outlet Temperature TIIOT - Wide Range Wide Range (WR) T"hot is shown in UFSAR Table 7.5-1 as a NRC Regulatory Guide (RG) 1.97 Al, BI, and B2 variable. There is one channel per :RCS loop with an indication range of 0 - 700°F. They are Class 1E instruments and provide indication on the Qualified Display Processing System (QDPS) in the control room. Input from each loop channel is also recorded. The WR Thor instrumentation is separate from the Thot input to ESFAS.

This instrumentation is used by the operator during normal operation3 to control cooling during cold shutdown and ensure the proper relationship between RCS pressure and temperature.

For post-accident functions, the RCS hot leg WR temperature instrumentation provides information to operators to verify adequate core cooling, RHR initiation conditions, and in conjunction with the RCS cold leg WR temperature indication, the effectiveness of RCS heat removal by the secondary system. RCS temperature is also used to determine if safety injection flow can be reduced.

System redundancy is provided by having a channel of RCS hot leg WR temperature for each RCS loop. Functional diversity for determination of core cooling identified in UFSAR Table 7B.5-1 includes core exit temperature, reactor vessel water level, and RCS subcooling. Functional redundancy for determination

Attachment I NOC-AE-06002060 Page 4 of secondary heat sink is provided by steam generator water level, AFW flow, and core exit temperature.

The wide range reactor coolant outlet temperature is an input to the cold overpressure mitigation system (COMS). However, the TS for the COMS function is not applicable in MODE 1, 2 & 3 where the Accident Monitoring Instrumentation TS applies.

4.2 Reactor Coolant Inlet Temperature TCOLD - Wide Range Wide Range (WR) Tcold is shown in UFSAR Table 7.5-1 as a RG 1.97 A1, B1, and B2 variable. There is one channel per RCS loop with an indication range of 0

- 700°F. They are Class 1E instruments and provide indication on the Qualified Display Processing System (QDPS) in the control room. Input from each loop channel is also recorded. The WR Tcold instrumentation is separate from the TCO'd input to ESFAS.

This instrumentation is used by the operator during normal operation3 to control cooling during cold shutdown and ensure the proper relationship between RCS pressure and temperature.

For post-accident functions, the RCS cold leg WR temperature can be used by the plant operators, in conjunction with the RCS hot leg WR temperature, to verify the effectiveness of RCS heat removal by the secondary system. RCS cold leg WR temperatures are monitored during steam generator depressurization to ensure that the depressurization does not impose a challenge to the Integrity Critical Safety Function.

System redundancy is provided by having a channel of WR RCS cold leg temperature for each RCS loop. Functional diversity for determination of secondary heat sink identified in UFSAR Table 7B.5-1 includes steam generator water level, AFW flow, and core exit temperature.

The wide range reactor coolant inlet temperature is an input to the cold overpressure mitigation system (COMS). However, the TS for the COMS function is not applicable in MODE 1, 2 & 3 where the Accident Monitoring Instrumentation TS applies.

4.3 Steam Generator Level - Wide Range The STP design includes 4 wide range steam generator level instruments, one associated with each of the 4 steam generators. The instruments provide indication in the control room. They provide no control or protection functions.

Steam Generator Level is monitored in the Emergency Operating Procedures (EOP) to assure availability of the secondary heat sink for post-accident decay NOC-AE-06002060 Page 5 heat removal. The SG level indication for this function in the EOPs is provided by Steam Generator Level - Narrow Range, which is not affected by this proposed change. The wide range SG level is used in the functional restoration procedure for loss of secondary heat sink to determine if RCS feed and bleed should be initiated.

Steam Generator Level - Wide Range is shown in UFSAR Table 7.5-1 as a RG 1.97 Al, BI, B2, and D2 variable. It is identified as a diverse backup to AFW Flow.

System redundancy of this function is provided by having 4 instruments, one for each steam generator. Functional diversity for heat sink availability identified in UFSAR Table 7B.5-1 includes Narrow Range SG Level, AFW flow, core exit temperature, and wide range RCS temperature.

4.4 Auxiliary Feedwater Flow STP has four trains of AFW, each feeding an associated steam generator. Train A, B, and C have motor-driven AFW pumps and Train D has a turbine-driven AFW pump. Train A, B, and C AFW are powered from ESF Train A, B, and C, respectively. Steam Generator D supplies steam to the Train D turbine-driven AFW pump. Instrumentation and control for the turbine-driven Train D AFW is provided by Train A. The AFW supply piping is cross-connected so that any AFW train can supply any steam generator. If implementation of the cross-connect is required, it is accomplished by manual action from the Control Room.

Each of the four trains of AFW is provided with one channel of AFW flow monitoring.

One train of AFW feeding an intact steam generator is sufficient for post-accident decay heat removal. STP's safety analyses show that three trains of AFW feeding three steam generators are required for sufficient RCS cooling to prevent the pressurizer from going water solid in a loss of normal feedwater (LONF) assuming failure of Train A ESF actuation to start Train A AFW and Train D AFW and with credit for operator action to manually start one of the failed AFW trains from the control room.

Note 'o' to STP UFSAR Table 7.5-1 describes the basis for the AFW Flow monitoring redundancy as being provided by one channel per loop and identifies Steam Generator Level - Wide Range as a diverse backup.

AFW flow is listed in UFSAR Table 7.5-1 as a RG 1.97 A1, B1, and D2 variable.

STP UFSAR Sec. 10.4.9 also describes AFW instrumentation:

NOC-AE-06002060 Page 6 "Control room instrumentation is provided to monitor major AFWS parameters, such as the discharge pressure of each AFW pump, turbine-driven AFW pump inlet steam pressure available through the plant computer, and AFW flow to each SG. Turbine-driven pump discharge pressure is available at a control room indicator and through the QDPS; the motor-driven pump discharge pressures are available through the Emergency Response Facilities Data Acquisition and Display System

[ERFDADS]. This instrumentation, in combination with the SG level indication described in Section 7.5, provides the operator with reliable indication of the AFWS performance."

The AFW flow transmitters also provide input through QDPS to AFW valve controllers to maintain flow in accordance with design.

AFW flow instrumentation is used in the Emergency Operating Procedures to define the potential loss of heat sink and the need to either establish another steam generator feed source or to initiate core cooling via RCS bleed and feed. It is used in accident classification procedure (Emergency Action Levels - EALs) to indicate the potential for the loss of the fuel rod cladding fission product barrier.

4.5 Safety Basis for Proposed Action The table below describes the operator action associated with the functions covered by the TS change. The four functions are RG 1.97 Type A variables. The STP UFSAR criteria for a Type A variable are that they provide indication that enables the operator to:

  • Perform the diagnosis specified in WOG ERGs
  • Take the specified preplanned, manually controlled actions for which no automatic control is provided that are required for safety systems to accomplish their safety function in order to recover from the DBA event, and

" Reach and maintain a safe shutdown condition.

The table describes each of the affected functions, discusses the effect of a loss of one, two, three, or four channels of each function, and compares the proposed STP requirement to the NUREG-1431 requirement. There is no proposed configuration where TS 3.0.3 would apply, which is consistent with the application of the corresponding NUREG-1431 requirements; i.e. the action associated with loss of the indication function is a 7-day completion time or shutdown.

Attachment I NOC-AE-06002060 Page 7 Function Function and Design Margin Number STP Effect of Loss of Channel(s) NUREG-1431 Comparison of Chan. Action (Total Inop Channels)

AFW Flow One train of AFW feeding an intact I ACTION Redundancy is provided by operable AFW NUREG-1431 specifies 2 required channels steam generator is adequate for post- 35.a flow indications in the other three loops, which are not identified as loop-specific. With 4 (I/loop) accident decay heat removal. In Diverse indication is provided by the WR one channel inoperable, the operator would rely addition, manual cross-connect SGWL channel. Narrow Range (NR) on the operable channel to determine AFW capability from the Control Room SGWL is also likely to be available for Flow. The NUREG Bases notes that SGWL is allows any AFW train to feed any SG. most events. The operators have adequate the primary indication of adequate inventory in Three trains of AFW feeding three information to evaluate steam generator the secondary for heat removal.

steam generators are required for heat removal and respond appropriately. The NUREG imposes a 30-day AOT with a sufficient RCS cooling to prevent the The proposed TS is a 30-day allowed requirement for a report to the NRC.

pressurizer from going water solid in a outage time (AOT) with a requirement for With one inoperable channel STP's capability loss of normal assuming failurefeedwater of Train (LONF)

A ESF a report to NRC. Witsonexcee thanned in the theabilit meets or exceeds that required in NUREG actuation to start Train A AFW and because of the overall redundancy in STP's Train D AFW and with credit for four trains of AFW and the availability of the TrinD___anitcedto SGWL indication.

operator action to manually start one of the failed AFW trains from the 2 ACTION Redundancy is provided by operable AFW With two inoperable channels, the NUREG control room. 35.b flow indications in two other loops, treats the AFW flow indication function as lost.

Diverse indication for the loops with The SGWL indication would still be available.

inoperable AFW flow is provided by the The NUREG imposes a 7-day AOT with a WR SGWL. NR SGWL is also likely to be shutdown action for this condition.

available for most events.

The proposed TIS is a 7-day AOT with a STP would not lose the AFW flow indication shutdown actions function because there would still be AFW flow indication for two loops. SGWL indication is still available.

3 ACTION AFW flow indication is available in one STP would not lose the AFW flow indication 35.b loop. Diverse indication for the loops with function because there would still be AFW flow inoperable AFW flow is provided by the indication for one loop. SGWL indication is WR SGWL. The proposed TS is a 7-day still available. The STP action for this AOT with a shutdown action. condition is the same as the NUREG action for a loss of function; i.e. 7-day shutdown action.

1 This scenario is not included in the comparison. This event already includes a single failure (i.e. Train A ESF). If LONF were postulated while channels of AFW or SGWL were in inoperable, the ESF failure is not required to be postulated concurrently. Also, the ESF failure does not affect AFW or WR SGWL indication.

NOC-AE-06002060 Page 8 Function Function and Design Margin Number STP Effect of Loss of Channel(s) NUREG-1431 Comparison of Chan. Action (Total Inop Channels) 4 ACTION No direct AFW flow indication is The STP condition corresponds to a loss of 35.b available; however, diverse indication for AFW flow indication function, for which the AFW flow is provided by the WR SGWL. NUREG also requires a 7-day shutdown action.

The proposed TS is a 7-day AOT with a shutdown action.

WR Steam One train of AFW feeding an intact I ACTION Redundancy is provided by operable WR NUREG-1431 specifies 2 required channels per Generator steam generator is adequate for post- 35.a SGWL in the other three generators. steam generator. With one inoperable channel, Level accident decay heat removal. As noted in the Design Margin column, there would SG.

the affected still Because be one operable channel of the "per steamfor 4 (I/SG) Three trains of AFW feeding three WR SGWL is used in the functional generator" wording of the NUREG, this action steam generators are required for restoration procedure for loss of secondary could apply t o more than one SG at a time (i.e.,

sufficient RCS cooling to prevent the heat sink to determine if RCS feed and I channel/loop could be inoperable on 4 loops pressurizer from going water solid in a bleed should be initiated. Since restoration for a maximum of 4 inoperable channels). The loss of normal feedwater (LONF) of only one SG as a heat sink is required to NUr bases statesathe unensate assuming failure of Train A ESF restore the secondary heat sink function, level signal provides input to the Emergency actuation to start Train A AFW and the remaining WR indication capability is Feedwater Control System. 2 Train D AFW and with credit for acceptable.

operator action to manually start one Narrow Range SG Level will be used when The NUREG imposes a 30-day AOT with a of the failed AFW trains from the control it is within its range. requirement for a report to the NRC.

room.itiwihntsrge STP has only one channel per steam generator Steam Generator Level is monitored in AFW flow indication is also an acceptable and loss of that level indication would require the Emergency Operating Procedures indication of secondary heat sink and AFW the operator to rely on diverse indications of (EOP) to assure availability of the Flow is a diverse indication for WR heat sink availability, such as AFW flow or WR secondary heat sink for post-accident SGWL. RCS temperature. The STP WR SGWL does decay heat removal. The SG level The proposed TS is a 30-day allowed not perform a control function for the AFW indication for this function in the outage time (AOT) with a requirement for system.

EOPs is provided by Steam Generator a report to NRC. II 2 Any TS action for with regard to the control function would be related to the control's role as a required support system for EFS, not for its post accident monitoring function.

NOC-AE-06002060 Page 9 Function Function and Design Margin Number STP Effect of Loss of Channel(s) NUREG-1431 Comparison orChan. Action (Total Inop Channels)

Level - Narrow Range, which is not 2 ACTION Redundancy is provided by operable WR With two inoperable channels, the WR SGWL affected by this proposed change. The wide range SG level is used in the 35.b SGWL in two generators. Since restoration function for the associated steam generator is functional restoration procedure for of only one SG as a heat sink is required to lost. There would still be WR SGWL loss of secondary heat sink to restore the secondary heat sink function, indication for the other SGs. However, the "per determine if RCS feed and bleed the remaining WR indication capability is steam generator" wording of the NUREG should be initiated. acceptable. allows the required action to be applied separately to each SG, so it is possible that the AFW flow indication is also an acceptable action could be applied to more than one SG at indication of secondary heat sink and AFW a time; i.e., up to a loss of function.

Flow is a diverse indication for WR SGWL. The NUREG imposes a 7-day AOT with a shutdown action for this condition.

The proposed TS is a 7-day AOT with a shutdown action. STP"s required action is comparable to that of the NUREG. However, STP would not have a loss of function with indication in two SGs.

3 ACTION Indication is provided by operable WR This would correspond to three SG with 2 35.b SGWL in one generator. Since restoration inoperable channels and the 7-day shutdown of only one SG as a heat sink is required to action would apply from the time the action restore the secondary heat sink function, was entered for the first SG.

the remaining WR indication capability is acceptable. STP's required action is comparable to that of the NUREG.

AFW flow indication is also an acceptable indication of secondary heat sink and AFW Flow is a diverse indication for WR SGWL.

The proposed TS is a 7-day AOT with a shutdown action.

4 ACTION AFW flow would be the indication of a This would correspond to four SG with 2 35.b secondary heat sink. The proposed TS is a inoperable channels (loss of function) and the 7-day AOT with a shutdown action. 7-day shutdown action would apply from the time the action was entered for the first SG.

Narrow Range SG Level can be used when it is within range. STP's required action is comparable to that of the NUREG.

n ______________________________________________________________

L .1.

Attachment I NOC-AE-06002060 Page 10 Function Function and Design Margin Effect of Loss of Channel(s) NUREG-.1431 Comparison (Total Channels)

WR RCS For post-accident functions, the RCS Redundancy is provided by the operable The NUREG is written for 2 Tcold indications Tcold cold leg WR temperature can be used WR Tcold indications in the other three per loop. With one inoperable channel for by the plant operators, in conjunction RCS cold legs. more than 30 days, the NUREG requires a 4 (I/loop) with the RCS hot leg WR temperature, report to the NRC. Because of the "per loop" to verify the effectiveness of RCS heat Availability of the secondary heat sink is wording of the NUREG, this action could apply removal by the secondary system. indicated by the RCS temperature to more than one loop at a time (i.e., 1 RCS cold leg WR temperatures are indications on the other three loops. AFW channel/loop could be inoperable on 4 loops for monitored during steam generator flow, and SGWL are the primary a maximum of 4 inoperable channels). In this depressurization to ensure that the indications of secondary heat sink. The configuration, one operable channel would be depressurization does not pose a integrity Critical Safety Function is entered available for each loop.

challenge to the Integrity Critical if ALL cold leg temperatures are less than Safety Function. a prescribed threshold for a given pressure, With one inoperable channel, the STP so the availability of three loop indications configuration corresponds to a NUREG System redundancy is provided by is adequate to determine if the CSF may be condition with two inoperable channels in one having a channel of WR RCS cold leg challenged. loop. The NUREG imposes a 7-day AOT with temperature for each RCS loop. a shutdown action for this condition if the Functional diversity for determination SG pressure also provides effective inoperable channel is not restored.

of secondary heat sink includes steam alternate indication.

generator water level, AFW flow, and The proposed TS is a 30-day allowed core exit temperature. outage time (AOT) with a requirement for a report to NRC.

2 ACTION Redundancy is provided by operable WR The STP configuration corresponds to two 35.a Tcold indications in two RCS cold legs. loops with 2 inoperable channels. In this configuration, the NUREG requires a 7-day Availability of the secondary heat sink is shutdown action, which would apply from the indicated by the RCS temperature time the action was entered for the first loop.

indications on the other two loops. AFW flow, and SGWL are primary indications of The STP required action is the same as that of secondary heat sink. The integrity Critical the NUREG.

Safety Function is entered if ALL cold leg temperatures are less than a prescribed threshold for a given pressure, so the availability of two loop indications is adequate to determine if the CSF may be challenged.

The proposed TS is a 7-day AOT with a shutdown action.

NOC-AE-06002060 Page 11 Effect of Loss of Channel(s) NUREG-1431 Comparison Function Function and Design Margin ofNumber Chn.

Inop STP Ation Ac (Total _ion Channels) 3 ACTION Information for the operator is provided by The STP configuration corresponds to three 35.b an operable WR Tcold indication in one loops with 2 inoperable channels. In this RCS cold leg. configuration, the NUREG requires a 7-day shutdown action, which would apply from the Availability of the secondary heat sink is time the action was entered for the first loop.

indicated by the operable RCS temperature indication. Thot and CET also provide The STP required action is the same as that of RCS temperature information. AFW flow, the NUREG.

and SGWL are primary indications of secondary heat sink. The integrity Critical Safety Function is entered if ALL cold leg temperatures are less than a prescribed threshold for a given pressure, so the availability of one loop indication is adequate to determine if the CSF may be challenged.

The proposed TS is a 7-day AOT with a shutdown action.

4 ACTION Information for the operator is provided by The STP configuration corresponds to four 35.b alternate indications. loops with 2 inoperable channels. In this configuration, the NUREG requires a 7-day Thot and CET also provide RCS shutdown action, which would apply from the temperature information. AFW flow, and time the action was entered for the first loop.

SGWL are primary indications of secondary heat sink. The integrity Critical For both STP and the NUREG, the Tcold Safety Function is entered if ALL cold leg indication function is lost and the STP action is temperatures are less than a prescribed the same as that of the NUREG for this threshold for a given pressure, so the condition.

unavailability of any loop indication impairs the ability to determine if the CSF may be challenged.

The proposed TS is a 7-day AOT with a shutdown action.

NOC-AE-06002060 Page 12 Function Function and Design Margin Number STP Effect of Loss of Channel(s) NUREG-1431 Comparison of Chan. Action (Total Inop Channels)

WR RCS For post-accident functions, the RCS I ACTION Redundancy is provided by operable Thot The NUREG is written for 2 Thot indications Thot hot leg WR temperature 35.a indications in three loops, per loop. With one inoperable channel for instrumentation provides information One inoperable channel has no significant more than 30 days, the NUREG requires a (I/loop) to operators to verify adequate core impactreport to the NRC. Because of the "per loop" cooling, RHR initiation conditions, and on thanges in cor e wording of the NUREG, this action could apply and in conjunction with the RCS cold and respond to changes in core cooling, to more than one loop at a time (i.e., I leg WR temperature indication, the and decay heat removal, or to manage SI channel/loop could be inoperable on 4 loops for effectiveness of RCS heat removal by a maximum of 4 inoperable channels). In this the secondary system. RCS The proposed TS is a 30-day allowed configuration, one operable channel would be temperature is also used to determine outage time (AOT) with a requirement for available for each loop.

if safety injection flow can be reduced. a report to NRC. With one inoperable channel, the STP System redundancy is provided by configuration corresponds to a NUREG having a channel of RCS hot leg WR condition with two inoperable channels in one temperature for each RCS loop. loop. The NUREG imposes a 7-day AOT with Functional diversity for determination a shutdown action for this condition if the of core cooling identified in UFSAR inoperable channel is not restored.

Table 7B.5-1 includes core exit NOC-AE-06002060 Page 13 Function Function and Design Margin Number ofChan. STP Effect of Loss of Channel(s) NUREG-1431 Comparison (Total Inop Action Channels) temperature, reactor vessel water level, 2 ACTION Redundancy is provided by operable Thot The STP configuration corresponds to two and RCS subcooling. Functional 35.b indication in two loops, loops with 2 inoperable channels. In this redundancyconfiguration, the NUREG requires a 7-day secondary heat sink is provided by With two operable Thot indications, the shutdown action, which would apply from the steam generator water level, AFW operators' are able to assess and respond to time the action was entered for the first loop.

flow, and core exit temperature. changes in core cooling and decay heat The STP proposed action is consistent with that removal. In addition to the two operable of the NUREG.

Thot channels, the operators have comparable RCS temperature information from CETs. Four channels of WR Tcold are available. The primary indicators of secondary heat sink are AFW and SGWL.

SI flow management is primarily based on subcooling margin from CETs. Thot is a criterion used to start LHSI if the subcooling margin criteria is not met; however, even if the Thot indication is not available, the procedure will lead the operator to start SI based on subcooling margin from CET.

The proposed TS is a 7-day AOT with a shutdown action..

Attachment I NOC-AE-06002060 Page 14 Function Function and Design Margin Number STP Effect of Loss of Channel(s) NUREG-1431 Comparison of Chan. Action (Total Inop Channels) 3 ACTION Information for the operator is provided by The STP configuration corresponds to three 35.b an operable WR Thot indication in one loops with 2 inoperable channels. In this RCS cold leg. configuration, the NUREG requires a 7-day shutdown action, which would apply from the With one operable Thoat indication, the time the action was entered for the first loop.

operators' are able to assess and respond to The STP required action is consistent with that changes in core cooling and decay heat of the NUREG.

removal. In addition to the operable Thot channels, the operators have comparable RCS temperature information from CETs.

Four channels of WR Tcold are available.

The primary indicators of secondary heat sink are AFW and SGWL. SI flow management is primarily based on subcooling margin from CETs. Thot is a criterion used to start LHSI if the subcooling margin criteria is not met; however, even if the Thot indication is not available, the procedure will lead the operator to start SI based on subcooling margin from CET.

The proposed TS is a 7-day AOT with a shutdown action.

NOC-AE-06002060 Page 15 Function Function and Design Margin of ChaN. STP Effect of Loss of Channel(s) NUREG-1431 Comparison (Total Inop Action Channels) 4 ACTION Information for the operator is provided by The STP configuration corresponds to four 35.b alternate indications. loops with 2 inoperable channels. In this configuration, the NUREG requires a 7-day The operators can assess core cooling by shutdown action, which would apply from the reference to Tcold and CETs. AFW Flow time the action was entered for the first loop.

and SGWL provide adequate indication of For both STP and the NUREG, the Thot secondary heat removal. SI flow indication function is lost and the required management is primarily based on action is the same.

subcooling margin from CETs. Thot is a criterion used to start LHSI if the subcooling margin criteria is not met; however, even if the Thot indication is not available, the procedure will lead the operator to start SI based on subcooling margin from CET.

The proposed TS is a 7-day AOT with a shutdown action.

Attachment I NOC-AE-06002060 Page 16 4.5.1 Reactor Coolant Outlet Temperature TIo-T - Wide Range Reactor Coolant Inlet Temperature TCOLD - Wide Range Standard requirements for the accident monitoring functions in Westinghouse plants are provided in NUREG-1431. For the wide range reactor coolant temperatures, NUREG-1431 Table 3.3.3-1 shows 2 required channels per loop. As described earlier, the STP design has one channel of THOT - Wide Range and TCOLD - Wide Range per loop.

The proposed TS change to revise the Minimum Channels Operable requirement from a restrictive lI/loop to 2 operable channels (input from any two loops) is acceptable because it accounts for the redundancy associated with these functions. Two operable channels will -provide the operator with adequate information to implement the Emergency Operating Procedures.

The current TS requires entry into a 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> shutdown action if the I/loop Minimum Channels Operable requirement for RCS wide range temperature function is not met. 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> leaves the operator with little time to implement corrective action before a plant shutdown is required.

There is very little likelihood of an event requiring a post-accident monitoring function in the time that one or more channels are inoperable and imposing a plant shutdown is not a prudent requirement considering the redundancy and functional diversity for the wide range RCS temperature functions.

The proposed change provides substantially more operating margin. As described in the table above, the redundancy and availability of alternate indication minimize the potential for adverse effect on operator accident response. The 30-day action to restore one inoperable channel or submit a Special Report provides time for the station to correct the inoperable condition or to implement a pre-planned alternative indication.

With two or more channels inoperable, the 7-day shutdown requirement of ACTION 35b limits the time that the plant can operate with the degraded function; however, as described above, diverse indications are. still available for the operator in the unlikely event of an accident -requiring the function. As stated in the NUREG-1431 Bases for Post Accident Monitoring (PAM):

... The Completion Time of 7 days is based on the relatively low probability of an event requiring PAM instrument operation and the availability of alternate means to obtain the required

Attachment 1 NOC-AE-06002060 Page 17 information. Continuous operation with two 3 required channels inoperable in a Function is not acceptable because the alternate indications may not fully meet all performance qualification requirements applied to the PAM instrumentation. Therefore, requiring restoration of one inoperable channel of the Function limits the risk that the PAM Function will be in a degraded condition should an accident occur.

4.5.2 SG Level - Wide Range and AFW Flow Standard requirements for the accident monitoring functions in Westinghouse plants are provided in NUREG-1431. For the SG Level - Wide Range, NUREG-1431 Table 3.3.3-1 shows 2 required channels per steam generator. As described earlier, the STP design has one channel of SG Level - Wide Range for each steam generator.

For the AFW Flow, NUREG-1431 Table 3.3.3-1 shows 2 required channels per steam generator. As described earlier, the STP design has one channel of AFW Flow for each steam generator.

One train of AFW feeding an intact steam generator is sufficient for post-accident decay heat removal. However, the event selected for determination of the minimum channels operable requirement for AFW flow and wide-range steam generator level indication is the loss of normal feedwater (LONF) with worst-case single failure. For the LONF, the licensing basis requirement for the pressurizer not to go solid is more restrictive than the requirement for decay heat removal.

STP's safety analyses show that three trains of AFW feeding three steam generators are required for sufficient RCS cooling to prevent the pressurizer from going water solid in a LONF assuming failure of Train A ESF actuation to start Train A AFW and Train D AFW and with credit for operator action to manually start one of the failed AFW trains from the control room. For this event, the three operable channels for both AFW and SG water level - NR provide adequate indication. Therefore maintaining a Minimum Channels Operable Requirement of 4 channels is conservative because no additional failures of AFW furctions are required to be postulated so that any three of the AFW trains and associated flow indication can be assumed to be available.

For one inoperable channel of wide range SG level indication or one inoperable channel of AFW flow indication, Required Action A in NUREG-1431 is to restore the inoperable channel within 30 days or submit a report. The NUREG Bases for the required action states:

3 In comparing the STP requirement to the NUREG, "two" should be interpreted as "all" because the Bases is describing a condition involving a loss of the indication function.

NOC-AE-06002060 Page 18 The 30-day Completion Time is based on operating experience and takes into account the remaining OPERABLE channel (or in the case of a Function that has only one required channel, other non-Regulatory Guide 1.97 instrument channels to monitor the Function), the passive nature of the instrument (no critical automatic action is assumed to occur from these instruments), and the low probability of an event requiring PAM instrumentation during this interval.

STP's current Technical Specifications require 1 channel per steam generator.

Note 'o' to STP UFSAR Table 7.5-1, states, "...the required redundancy is provided by one channel per loop." Although the note is appended to the AFW Flow function, it applies equally to the diverse steam generator level function that it also mentions. As discussed above, the proposed change to the TS establishes a Minimum Channels Operable requirement of 3 channels for both functions. Thus, consistent with the NUREG-1431 precedent, STPNOC proposes a 30-day allowed outage time with a requirement for a report if one of the required channels is inoperable. The redundancy and availability of diverse indication described earlier provide the safety basis. Continued operation beyond the 30 days requires an alternate method of monitoring the function, which provides single failure protection in the very unlikely event the function is required in that time.

Because only one train of AFW feeding one intact steam generator is adequate for post-accident decay heat removal, there is design margin in having four trains of AFW with cross-connect capability such that any AFW train can feed any one of the steam generators. This AFW margin extends to the AFW Flow function.

Similarly, since only one of four steam generators is required for effective decay heat removal, there is design margin for the steam generator level requirements. It can be concluded that three operable channels for both functions is adequate for the post-accident decay heat removal and identification of the need to initiate feed and bleed aspect of their function and the 30-day action is acceptable; therefore, maintaining a Minimum Channels Operable Requirement of four channels is conservative.

For conditions where none of a function's channels are operable, the required completion time in Required Action C of the NUREG is 7 days. If the function is not restored, a shutdown is required. The Bases for the NUREG states:

"...The Completion Time of 7 days is based on the relatively low probability of an event requiring PAM instrument operation and the availability of alternate means to obtain the required information.

Continuous operation with two required channels inoperable in a Function is not acceptable because the alternate indications may not fully meet all performance qualification requirements applied to the PAM instrumentation. Therefore, requiring restoration of one inoperable channel

Attachment I NOC-AE-06002060 Page 19 of the Function limits the risk that the PAM Function will be in a degraded condition should an accident occur."

Consistent with the precedent in NUREG-1431, the proposed TS would require entry into the 7-day shutdown action if two or more of the four required SG wide range level instruments or AFW flow instruments were inoperable. There is safety margin in this requirement in the availability of the functionally diverse indications and that unavailability of the level indication or the AFW flow indication does not make the associated steam generator unavailable as a heat sink if it is receiving flow. With respect to the LONF event, the 7-day action is conservative because steam generator level can still be used to confirm AFW flow to the steam generator in the absence of AFW flow indication in the unlikely event of an accident with two of the AFW flow channels inoperable. With respect to the post-accident decay heat removal and determination of the need to initiate feed and bleed, the 7-day action is conservative because it can reasonably be expected that AFW flow and indication and steam generator level indication will be available for at least one generator in the unlikely event of an accident with two channels of either function inoperable.

4.5.3 Administrative Change to Technical Specification 3.3.3.6 ACTION 38 ACTION 38 in the current Technical Specifications is not referenced in Table 3.3-

10. It was the action originally referenced by containment pressure, steam line pressure, and steam generator water level - narrow range. Those functions were revised to reference ACTION 43 in Amendment 23/13 to the Technical Specifications, leaving no accident monitoring function referencing ACTION 38.

Deletion of the ACTION 38 requirements is an administrative change with no safety significance.

5.0 Regulatory Safety Analysis 5.1 No Significant Hazards Determination STPNOC has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10CFR50.92, "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.

The proposed increase in the allowed outage times for the Reactor Coolant Outlet Temperature - Wide Range, Reactor Coolant Inlet Temperature - Wide Range,

Attachment I NOC-AE-06002060 Page 20 Steam Generator Level - Wide Range and the AFW Flow does not involve a significant increase in the probability of an accident previously evaluated because these are accident monitoring functions that have no effect on the potential for accident initiation. The proposed deletion of the existing requirements in ACTION 38 is an administrative change. Since these requirements are not currently applied to any plant equipment, this change cannot affect the probability of any accident previously evaluated.

The proposed increase in the allowed outage times for the Reactor Coolant Outlet Temperature - Wide Range, Reactor Coolant Inlet Temperature - Wide Range, and Steam Generator Level - Wide Range and AFW Flow does not involve a significant increase in the consequences of an accident previously evaluated because the availability of redundant and diverse indications provides adequate assurance that the operator will be able to determine the post-accident status of the secondary heatsink.

The proposed deletion of the existing requirements in ACTION 38 is an administrative change. Since these requirements are not currently applied to any plant equipment, this change cannot affect the consequence of any 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 increase in the allowed outage times for the Reactor Coolant Outlet Temperature - Wide Range, Reactor Coolant Inlet Temperature - Wide Range, Steam Generator Level - Wide Range and the AFW Flow does not create the possibility of a new or different kind accident from any accident previously evaluated because the proposed change affects only the allowed outage time for accident monitoring instrumentation and involves no changes to plant design, plant configuration or operating procedures.

The proposed deletion of the existing requirements in ACTION 38 is an administrative change. Since these requirements are not currently applied to any plant equipment, this change cannot create the possibility of any kind of accident.

3) Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed increase in the allowed outage times for the Reactor Coolant Outlet Temperature - Wide Range, Reactor Coolant Inlet Temperature - Wide Range, Steam Generator Level - Wide Range and AFW Flow does not involve a NOC-AE-06002060 Page 21 significant reduction in the margin of safety because the availability of redundant and diverse indications provides adequate assurance that the operator will be able to determine the post-accident status of the secondary heatsink.

The proposed deletion of the existing requirements in ACTION 38 is an administrative change. Since these requirements are not currently applied to any plant equipment, this change cannot affect the margin of safety.

Conclusion Based upon the analysis provided herein, the proposed amendments do not involve a significant hazards consideration.

5.2 Applicable Regulatory Requirements/Criteria Accident Monitoring Instrumentation:

Required accident monitoring instrumentation ensures that there is sufficient information available on selected unit parameters to monitor and to assess unit status and behavior following an accident. These essential instruments are identified in the STP UFSAR where it addresses the recommendations of Regulatory Guide 1.97 as required by Supplement 1 to NUREG-0737, "TMI Action Plan Requirements for Applicants for an Operating License".

The instrument channels required to be OPERABLE by TS 3.3.3.6 include parameters identified during unit specific implementation of Regulatory Guide 1.97 as Type A variables.

Type A variables are included in this Technical Specification Limiting Condition for Operation (LCO) because they provide the primary information required for the control room operator to take specific manually controlled actions for which no automatic control is provided, and that are required for safety systems to accomplish their safety functions for design basis accidents (DBAs).

As discussed in the Safety Bases, there is adequate redundancy for the affected accident monitoring functions. The proposed changes to the Technical Specifications would not change the function of the affected instrumentation. Therefore STPNOC has determined that there is no impact on compliance with the regulatory requirements.

Attachment I NOC-AE-06002060 Page 22 6.0 Environmental Considerations 10 CFR 51.22(b) specifies the criteria for categorical exclusion from the requirements for a specific environmental assessment per 10 CFR 51.21. This amendment request meets the criteria specified in 10 CFR 51.22(c)(9). The specific criteria contained in this section are discussed below.

(i) the amendment involves no significant hazards consideration As demonstrated in the No Significant Hazards Consideration Determination, the requested license amendment does not involve any significant hazards consideration.

(ii) there is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite The requested license amendment involves no change to the facility and does not involve any change in the manner of operation of any plant systems involving the generation, collection or processing of radioactive materials or other types of effluents. Therefore, no increase in the amounts of effluents or new types of effluents would be created.

(iii) there is no significant increase in individual or cumulative occupational radiation exposure The requested license amendment involves no change to the facility and will not increase the radiation dose resulting from the operation of any plant system. Furthermore, implementation of this proposed change will not involve work activities that could contribute to occupational radiation exposure. Therefore, there will be no increase in individual or cumulative occupational radiation exposure associated with this proposed change.

Based on the above it is concluded that there will be no impact on the environment resulting from this change. The change meets the criteria specified in 10 CFR 51.22 for a categorical exclusion from the requirements of 10 CFR 51.21 relative to specific environmental assessment by the Commission.

7.0 References *

1. NUREG-1431 "Standard Technical Specifications, Westinghouse Plants"
2. STP UFSAR

NOC-AE-06002060 ATTACHMENT 2 ANNOTATED TECHNICAL SPECIFICATION PAGES

Attachment 2 NOC-AE-06002060 Page 1 TABLE 3.3-10 (D

0 ACCIDENT MONITORING INSTRUMENTATION C

-I TOTAL MINIMUM r NO. OF CHANNELS m-x INSTRUMENT CHANNELS OPERABLE ACTION CD

1. Containment Pressure 4 1 43
2. Reactor Coolant Outlet Temperature- 4 (1/loop) 44"oep 35 T HOT (Wide Range)
3. Reactor Coolant Inlet Temperature- 4 (1/loop) 4446eo 35 T COLD (Wide Range)
4. Reactor Coolant Pressure - Wide Range 6i) 3 1 37 and Extended Range ca 5. Pressurizer Water Level 4 1 43
6. Steam Line Pressure 4/steam generator 1/steam generator 43
7. Steam Generator Water Level - 4/steam generator 1/steam generator 43 Narrow Range coc
8. Steam Generator Water Level - 4 (1/steam generator) 35 ODO Wide Range 4 14'tea genora
9. Refueling Water Storage Tank Water Level 3 37 1
10. Auxiliary Feedwater Storage Tank Water Level 3 37 3 - 1T
11. Auxiliary Feedwater Flow 4 (1/steam generator) 35 0-0
12. Reactor Coolant System Subcooling 2 36 Margin Monitoring NOC-AE-06002060 Page 2 TABLE 3.3-10 (Continued)

ACTION STATEMENTS ACTION 35- a. With the number of OPERABLE channels ,one less than the Minimum Channels Operable requirement, restore at4east-eae the inoperable channel to OPERABLE status within-30 days 48he-, 199 in at days describing the heiws or submit a Special Report within the next 14 preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the Function to OPERABLE status.

b.. With the-numberof OPERABLE channels two or more less thanr the Minimum Channels Operable requirement, restore at least three channels to OPERABLE status within 7 days, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> ACTION 36- a. With the number of OPERABLE channels one less than the Total Number of Channels requirements, restore one inoperable channel to OPERABLE status within 7 days, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

b. With the number of OPERABLE channels less than the Minimum Channels Operable requirements, restore at least one inoperable channel to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

ACTION 37- a. With the number of OPERABLE channels one less than the Total Number of Channels requirements, restore the inoperable channel to OPERABLE status within 31 days, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

b. With the number of OPERABLE channels two less than the Total Number of Channels requirement, restore at least one inoperable channel to OPERABLE status within 7 days, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
c. With the number of OPERABLE channels less than the Minimum Channels Operable requirement, restore at least one inoperable channel to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

A/'*'I'I/'* k I rJn IAU?,L.

A - ,L.. ..... L---. .1 "'f ff Af'l f 1.. .... '.

M7.., N .ZC30F a. VVKH WE)u iiRrUM0r Of UpershAEI6ra uiijRiRiul uliiu 1966 Wanr -rtaii'~murnjrt cH-RR916 IRE reureets, restore the ineporablo channol to O)PE=RABLEr s~tatus Within 90 da',s, er be WIn a least HOT SHUTDOWN wi-thin the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

b. With the nu'mber of OPERABLE channels two loss than the Total Number cf-Ghannels req*uireme.ts, restore th, inoperab!e channel to OPERABLE status, within 21-days,"-,r-.in*pt least HOT SHUTDOWN within the neot 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
c. With the number of OPERABLE channols three loss than the Total Number of Ghannelr requiroment, restore at least one ineperable channel to OPERABLE status ,Athin7 days, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
d. With the number of OPERABLE channels less than the Minimum Channels-Operable requirement, restore at least one inoperable channel to OPERABLE status ,ithin 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or k-  ;- #f1--ot Un-r QUII ITI'*rMrAKl t*,;-h #k-, "--I "10hn,--e SOUTH TEXAS - UNITS 1 &2 3/4 3-70 Unit 1 Amendment No.

Unit 2 Amendment No.

NOC-AE-06002060 ATTACHMENT 3 TECHNICAL SPECIFICATION BASES INSERTS (For Information Only)

Attachment 3 NOC-AE-06002060 Page 1 Reactor Coolant Outlet Temperature (Thor) Wide Range and Reactor Coolant Inlet Temperature

( A)Wide Range (ACTION 35)

There is one channel of Wide Range (WR) Thot per RCS loop with an indication rancge of 0 -

700°F. They are Class 1E instruments and provide indication on the Qualified Display Processing System (QDPS) in the control room. Input from each loop channel is also recorded.

For post-accident functions, the RCS hot leg WR temperature provides information to operators to verify adequate core cooling, RCS subcooling, and in conjunction with the RCS cold leg WR temperature indication, the effectiveness of RCS heat removal by the secondary system. RCS temperature is also used to determine if safety injection flow can be reduced.

System redundancy is provided by having a channel of WR RCS hot leg temperature for each RCS loop. Functional diversity for determination of core cooling identified in UFSAR Table 7B.5-1 includes core exit temperature, reactor vessel water level, and RCS subcooling.

Functional redundancy for determination of secondary heat sink is provided by steam generator water level, AFW flow, and core exit temperature.

There is one channel of Wide Range (WR) Tcold per RCS loop with an indication range of 0 -

700°F. They are Class 1E instruments and provide indication on the Qualified Display Processing System (QDPS) in the control room. Input from each loop channel is also recorded.

For post-accident functions, the RCS cold leg WR temperature can be used by the plant operators, in conjunction with the RCS hot leg WR temperature, to verify the effectiveness of RCS heat removal by the secondary system. RCS cold leg WR temperatures are monitored during steam generator depressurization to ensure that the depressurization does not impose a challenge to the Integrity Critical Safety Function.

System redundancy is provided by having a channel of WR RCS cold leg temperatu:re for each RCS loop. Functional diversity for determination of secondary heat sink identified in UFSAR Table 7B.5-1 includes steam generator water level, AFW flow, and core exit temperature.

The Minimum Channels Operable requirement for the Reactor Coolant Temperature - Wide Range functions is four operable channels.

ACTION 35a establishes a 30-day allowed outage time with a requirement for a Special Report if one of the channels is inoperable. The redundancy and availability of diverse indication provide the safety basis. Continued operation beyond the 30 days requires an alternate method of monitoring the function, which provides single failure protection in the unlikely event the function is required in that time.

ACTION 35b requires entry into the 7-day shutdown action if two or more of the required channels are inoperable. There is safety margin in this requirement in the availability of the functionally diverse indications. The Completion Time of 7 days is based on the relatively low probability of an event requiring PAM instrument operation and the availability of alternate means to obtain the required information. Continuous operation with two or more required

Attachment 3 NOC-AE-06002060 Page 2 channels inoperable in a Function is not acceptable because the alternate indications may not fully meet all performance qualification requirements applied to the PAM instrumentation.

Therefore, requiring restoration of at least three channels of the Function limits the risk that the PAM Function will be in a degraded condition should an accident occur.

Steam Generator Water Level - Wide Range and AFW Flow (ACTION 35)

One train of AFW feeding an intact steam generator is sufficient for post-accident decay heat removal. However, the event selected for determination of the minimum channels operable requirement for AFW flow and wide-range steam generator level indication is the loss of normal feedwater (LONF) with worst-case single failure. For the LONF, the licensing basis requirement for the pressurizer not to go solid is more restrictive than the requirement for decay heat removal.

STP's safety analyses show that three trains of AFW feeding three steam generators are required for sufficient RCS cooling to prevent the pressurizer from going water solid in a LONF assuming failure of Train A ESF actuation to start Train A AFW and Train D AFW and with credit for operator action to manually start one of the failed AFW trains from the control room.. For this event, three channels of both AFW and SG water level - NR provided adequate indication.

because no additional failures of AFW functions are required to be postulated. Therefore, maintaining a Minimum Channels Operable Reqirement of four channels is conservative For one inoperable channel of wide range SG level indication or one inoperable channel of AFW flow indication, ACTION 35.a requires restoration the within 30 days or submit a report. The 30-day Completion Time is based on operating experience and takes into account the remaining OPERABLE channels, the passive nature of the instrument (no critical automatic action is assumed to occur from these instruments), and the low probability of an event requiting PAM instrumentation during this interval. Continued operation beyond the 30 days requires an alternate method of monitoring the function, which provides single failure protection in the very unlikely event the function is required in that time.

Because only one train of AFW feeding one intact steam generator is adequate for post-accident decay heat removal, there is design margin in having four trains of AFW with cross-connect capability such that any AFW train can feed any one of the steam generators. This AW margin extends to the AFW Flow function. Similarly, since only one of four steam generators is required for effective decay heat removal, there is design margin for the steam generator level requirements. Three channels for both functions is adequate for the post-accident decay heat removal and identification of the need to initiate feed and bleed aspect of their function and the 30-day action is acceptable.

ACTION 35.b requires entry into the 7-day shutdown action if two or more of the four required SG wide range level instruments or two or more of the four required AFW flow instruments are inoperable. The Completion Time of 7 days is based on the relatively low probability of an event requiring PAM instrument operation and the availability of alternate means to obtain the required information. There is safety margin in this requirement in the availability of the functionally diverse indications and that unavailability of the level indication or the AFW flow indication does not make the associated steam generator unavailable as a heat sink if it is receiving flow.

With respect to the LONF event, the 7-day action is conservative because steam generator level NOC-AE-06002060 Page 3 can still be used to confirm AFW flow to the steam generator in the absence of AFWI flow indication in the unlikely event of an accident with two of the AFW flow channels inoperable.

With respect to the post-accident decay heat removal and determination of the need to initiate feed and bleed, the 7-day action is conservative because it can reasonably be expected that AFW flow and indication and steam generator level indication will be available for at least one generator in the unlikely event of an accident with two or more channels of either function inoperable. Continuous operation with two or more required channels inoperable in a function is not acceptable because the alternate indications may not fully meet all performance qualification requirements applied to the PAM instrumentation. Therefore, requiring restoration of at least three operable channels of the function limits the risk that the PAM function will be in a degraded condition should an accident occur.

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