Text

Draft of TSTF-607, Changes to the Quadrant Power Tilt Ratio Technical Specification (PWROG-22021)
	ML25261A149
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Site:	Technical Specifications Task Force
Issue date:	09/17/2025
From:	; Technical Specifications Task Force
To:	; Office of Nuclear Reactor Regulation
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	TSTF-607
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TSTF-607, Rev. 0 PWROG-23, Rev. 0 NUREGs Affected:

Changes to the Quadrant Power Tilt Ratio Technical Specification (PWROG-22021)

Technical Specifications Task Force Improved Standard Technical Specifications Change Traveler 1430 1431 1432 1433 1434 Classification: 1) Technical Change Recommended for CLIIP?: Yes Correction or Improvement:

Improvement NRC Fee Status:

Not Exempt Benefit:

Prevents Unnecessary Actions Changes Marked on ISTS Rev 5.0 PWROG RISD & PA (if applicable): PA-ASC-1680 Revision History Affected Technical Specifications OG Revision 0 Revision Status: Active Original Issue Revision

Description:

Revision Proposed by:

PWROG Owners Group Review Information Date Originated by OG:

23-Jun-25 Owners Group Comments (No Comments)

Date: 16-Sep-25 Owners Group Resolution:

Approved TSTF Review Information TSTF Received Date:

04-Sep-25 Date Distributed for Review 04-Sep-25 TSTF Comments:

(No Comments)

Date: 17-Sep-25 TSTF Resolution:

Approved Action 3.1.1.D RTS Instrumentation Action 3.1.1.D Bases RTS Instrumentation Bkgnd 3.2.4 Bases QPTR LCO 3.2.4 QPTR LCO 3.2.4 Bases QPTR Action 3.2.4.A QPTR 17-Sep-25 Copyright(C) 2025, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

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TSTF-607, Rev. 0 PWROG-23, Rev. 0 Action 3.2.4.A Bases QPTR SR 3.2.4.1 QPTR SR 3.2.4.1 Bases QPTR SR 3.2.4.2 Deleted Change

Description:

QPTR SR 3.2.4.2 Bases Deleted Change

Description:

QPTR 17-Sep-25 Copyright(C) 2025, EXCEL Services Corporation. Use by EXCEL Services associates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited.

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TSTF-607, Rev. 0 Page 1 Table of Contents Table of Contents.................................................................................................................... 1

1.

SUMMARY

DESCRIPTION............................................................................................ 2

2.

DETAILED DESCRIPTION............................................................................................ 2 2.1.

System Design and Operation.................................................................................. 2 2.2.

Current Technical Specifications Requirements...................................................... 3 2.3.

Reason for the Proposed Change.............................................................................. 3 2.4.

Description of the Proposed Change........................................................................ 4

3.

TECHNICAL EVALUATION.......................................................................................... 5 3.1.

Justification for Adding a Note to LCO 3.2.4 to State That it is Not Required to be Met Until the Initial Calibration of the Excore Channels is Performed Per SR 3.3.1.6 Following a Refueling.................................................................................. 5 3.2.

Revise the QPTR Value from 1.00 to 1.02 in Required Action A.1........................ 6 3.3.

Add a New Required Action A.1.2, That Applies a Penalty to FQ and N

H F as an Alternative to Current Required Action A.1, With a QPTR Value of 1.02............. 6 3.4.

Justification for Revising the 12 Hour Frequency for SR 3.2.4.2............................ 7 3.5.

Delete Required Actions D.1.2, D.2.1 and D.2.2 in Technical Specification 3.3.1. 8 3.6.

Changes Not Discussed in PWROG-22021............................................................. 8 3.7.

PWROG-22021 Limitations and Conditions......................................................... 10

4.

REGULATORY EVALUATION................................................................................... 10

5.

REFERENCES................................................................................................................. 11 Model Application DRAFT

TSTF-607, Rev. 0 Page 2

1.

SUMMARY

DESCRIPTION The proposed change revises the Technical Specifications (TS) Actions and Surveillances associated with TS 3.2.4, "Quadrant Power Tilt Ratio (QPTR)" and TS 3.3.1, "Reactor Trip System (RTS) Instrumentation." The proposed change affects the Standard Technical Specifications (STS) for Westinghouse plant designs,1 and is justified in Topical Report PWROG-22021-P-A/NP-A, Revision 0, "Justifications for the Proposed Changes to the Quadrant Power Tilt Ratio Technical Specification," which was approved by the NRC on May 29, 20252.

2. DETAILED DESCRIPTION 2.1. System Design and Operation The core power distribution during operation is an assumption in the safety analyses. The core power distribution is predicted based on the fuel loading and verified by measurement during the fuel cycle. The core power distribution changes slowly during the cycle as fuel burnup is accumulated. The Heat Flux Hot Channel Factor, FQ(Z), and the Nuclear Enthalpy Rise Hot Channel Factor, N

H F, are the core peaking factors that are measured periodically during operation to ensure the safety analysis core power distribution assumptions are met.

The primary purpose of QPTR is to detect changes in the radial power distribution from one calibrated state to the next. It ensures that the previously measured core peaking factors are within their LCO limits. The Nuclear Instrumentation System (NIS) Power Range (PR) Neutron Flux detectors (the excore detectors designated as N-41, N-42, N-43, and N-44) are used to measure the QPTR. Each NIS PR Neutron Flux detector channel has an upper and lower detector. The QPTR is the ratio of the maximum upper excore detector calibrated output to the average of the upper excore detector calibrated outputs, or the ratio of the maximum lower excore detector calibrated output to the average of the lower excore detector calibrated outputs, whichever is greater. The "calibrated output" of each PR channel is adjusted when the incore power distribution is measured to indicate a QPTR near one. A QPTR value of 1.0 does not represent a zero incore power tilt, but rather indicates that the radial power distribution, as measured by the excore detectors, is consistent with the incore power distribution (including any existing incore power tilt) that was measured during the calibration. A QPTR value greater than 1.02 may indicate that a change has occurred in the gross radial power distribution but does not necessarily mean that the core peaking factors have exceeded their LCO limits.

The full power currents for a new fuel cycle are initially based on values from the previous cycle.

Therefore, a QPTR value other than 1.0 at the beginning of a new cycle simply indicates a change in radial power distribution from the previous cycle, and not necessarily an abnormal condition in the new core.

1 NUREG-1431 provides the STS for Westinghouse plant designs.

2 Email from Leslie Fields (NRC) to Dewey Olinski (Westinghouse), Agencywide Documents Access and Management System (ADAMS) Accession No. ML25148A288.

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TSTF-607, Rev. 0 Page 3 The NIS excore channels continuously monitor QPTR, and an alarm is generated if it exceeds 1.02. A QPTR not within the TS limit of 1.02 indicates the core power distribution may have changed since the last incore power distribution measurement and actions are required to ensure the safety analysis assumptions are still met.

2.2. Current Technical Specifications Requirements TS 3.2.4, "QPTR," requires the QPTR to be 1.02 when the reactor is in Mode 1 with thermal power > 50% of Rated Thermal Power (RTP).

SR 3.2.4.1 requires verification that QPTR is within its limit every 7 days or in accordance with the Surveillance Frequency Control Program (SFCP). SR 3.2.4.2, which may be performed in lieu of SR 3.2.4.1, requires verification that the QPTR is within limit using the movable incore detector system. SR 3.2.4.2 is used when one or more PR excore detectors are inoperable and thermal power is > 75% RTP. Some plant's TS permit the use of an incore power distribution monitoring system (PDMS) instead of the movable incore detector system to determine QPTR, and that option may be retained when adopting this traveler.

If QPTR is not within its limit, several Actions are required:

Thermal power must be reduced by 3% for each 1% that QPTR is greater than 1.0 within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ;

QPTR must be determined once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ;

The core peaking factors, FQ(Z) and N

H F, must be measured within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after achieving an equilibrium condition after the power reduction, and once per 7 days thereafter.

Prior to increasing thermal power, the safety analyses must be reevaluated to confirm the results remain valid for the duration of operation under the condition;

Prior to increasing thermal power, the excore detectors are normalized to restore QPTR to within limit; and

The core peaking factors, FQ(Z) and N

H F, must be measured within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after achieving an equilibrium condition, and within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months after increasing thermal power.

If QPTR is not restored to within its limit, reactor power must be reduced to less than 50% RPT within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

2.3. Reason for the Proposed Change The proposed change addresses several issues related to QPTR. First, the QPTR limit applies before the excore detectors have been calibrated at the beginning of a fuel cycle, and, as a result, the measured QPTR may not be indicative of the incore power distribution. Second, in order to adequately protect the safety analysis assumptions, the thermal power reduction should be based on the amount that the QPTR limit is exceeded. Third, the intent of reducing thermal power in order to establish additional margin to the peaking factor limits may also be accomplished by reducing the peaking factor limits to provide additional margin to the core peaking factor LCO limits assumed in the safety analysis. Fourth, requiring measurement of the QPTR every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months using the movable incore detector system when an excore channel is inoperable results in DRAFT

TSTF-607, Rev. 0 Page 4 significant wear on the system and is unnecessary if any control rod movement is monitored.

Lastly, the Actions in TS 3.3.1, "Reactor Trip System," are duplicative of the Actions in TS 3.2.4.

2.4. Description of the Proposed Change The following changes are made to TS 3.2.4, "QPTR."

The LCO is revised by the addition of a Note which states that the QPTR limit is not required to be met following refueling until after the initial performance of SR 3.3.1.6, which performs an incore/excore detector calibration.

Required Action A.1, which requires a reduction in thermal power by at least 3% from RTP for each 1% that QPTR exceeds 1.0, is revised to state that the reduction is 3% in thermal power for each 1% that QPTR exceeds the limit of 1.02.

Required Action A.1 is relabeled Required Action A.1.1 and is joined by a logical OR to a new Required Action A.1.2. Required Action A.1.2 requires reducing the limits on FQ(Z) and N

H F by at least 3% for each 1% that QPTR exceeds the limit of 1.02.

The Completion Times of Required Actions A.3, A.4, A.5, and A.6 are revised to reflect the option to follow Required Action A.1.1 or Required Action A.1.2.

Editorial improvements are made to Note 1 of SR 3.2.4.1.

SR 3.2.4.1, Note 2, is revised from stating that SR 3.2.4.2 may be performed in lieu of SR 3.4.2.1 to stating that the movable incore detector system can be used to determine QPTR.

SR 3.2.4.1 is revised to remove a requirement that the QPTR be verified to be within its limit "by calculation."

SR 3.2.4.2, which requires verifying QPTR every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months using the movable incore detector system when one or more Power Range Neutron Flux channels are inoperable and thermal power if greater than 75% RTP, is eliminated.

SR 3.2.4.1 is revised by the addition of a new Frequency which replaces SR 3.2.4.2. The new Frequency requires verification of QPTR once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months following any rod motion of at least 12 steps if the associated rod position indicator is inoperable. The new Frequency is modified by a Note that states it is only required to be performed if the calibrated output of one excore detector is unavailable and thermal power is greater than 75% RTP.

The following changes are made to TS 3.3.1, "RTS Instrumentation." Action D is applicable when one Power Range Neutron Flux - High channel is inoperable.

Required Action D.1.1 is relabeled Required Action D.1.

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TSTF-607, Rev. 0 Page 5

Required Action D.1.2, which requires reducing thermal power to at least 75% RTP, is eliminated.

Required Action D.2.1, which requires placing the channel in trip, is eliminated.

Required Action D.2.2, which requires performing SR 3.2.4.2, is eliminated.

The TS Bases are revised to reflect the change to the TS.

A model application is attached. The model should be used by licensees desiring to adopt the traveler following NRC approval.

3. TECHNICAL EVALUATION The technical justification for the proposed changes is provided in PWROG-22021-P-A/NP-A3, and is summarized below.

3.1. Justification for Adding a Note to LCO 3.2.4 to State That it is Not Required to be Met Until the Initial Calibration of the Excore Channels is Performed Per SR 3.3.1.6 Following a Refueling One proposed change to TS 3.2.4 is to add a Note stating that LCO 3.2.4 is not applicable until the initial calibration of the excore channels is performed per SR 3.3.1.6 following refueling.

Following a refueling outage, the full power current for each NIS PR channel is not known with certainty until it is measured at (or near) full power. Prior to startup after a refueling, only a predicted value for the full power current is available. The predicted detector currents are based on the predicted power distributions obtained from core design calculations and the excore power tilt that existed during the last incore-excore calibration flux map performed during the previous fuel cycle. Therefore, until the incore-excore calibration is performed for the new cycle, the QPTR represents the quadrant power tilt that was present at the end of the previous cycle. The QPTR is intended to indicate a change in the radial power distribution from a steady-state, known power distribution, which cannot be done until an incore-excore calibration is performed as required by SR 3.3.1.6.

In the NRC safety evaluation for PWROG-22021-P-A/NP-A, Section 3.1, the NRC staff found that the addition of the proposed Note to LCO 3.2.4 is justified because the full power currents for the new cycle are not determined until the first incore-excore calibration is performed per SR 3.3.1.6. Therefore, this LCO would not apply for a new fuel cycle following a refueling outage until SR 3.3.1.6 is performed. Performance of this SR ensures that the full power currents used by the PR NIS to calculate the QPTR are representative of the new core.

3 The approved version of the topical report, which includes the NRC's safety evaluation, was transmitted to the NRC on August 27, 2025, and is available under ADAMS Accession No. ML25231A213.

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TSTF-607, Rev. 0 Page 6 3.2. Revise the QPTR Value from 1.00 to 1.02 in Required Action A.1 One proposed change to TS 3.2.4 is to revise the QPTR value of 1.00 to 1.02 in Required Action A.1.

Most reload safety analysis calculations are based on core calculations that are quadrant symmetric. To account for potential incore tilt during operation, additional nuclear design allowances are applied to the reload calculations and core peaking factors. The calculational uncertainty for FQ(Z) and N

H F also contains a component for core tilt. As a result, the reload safety analysis methodologies conservatively bound a QPTR value up to 1.02. Since a QPTR value of 1.02 does not result in challenging the core peaking factors, there is no need to reduce power for a QPTR value between 1.00 and 1.02 to ensure that adequate margin exists. It is more appropriate to reduce power only when the QPTR exceeds the LCO limit of 1.02, and Required Action A.1 is therefore be revised to reflect the LCO limit of 1.02.

In the NRC safety evaluation for PWROG-22021-P-A/NP-A, Section 3.2, the NRC staff found that the reload safety analysis methodologies conservatively bound a QPTR value up to 1.02 because the QPTR limit of 1.02, at which corrective action is required, provides a margin of protection for both the departure from nucleate boiling (DNB) ratio and the linear heat generation rate. The NRC staff found it acceptable that there is no need to reduce power for a QPTR value between 1.00 and 1.02 because the 1.02 value does not result in challenging the core peaking factor limits.

3.3. Add a New Required Action A.1.2, That Applies a Penalty to FQ and N

H F as an Alternative to Current Required Action A.1, With a QPTR Value of 1.02 One proposed change to TS 3.2.4 is to add a new Required Action A.1.2 as a logical OR alternative to current Required Action A.1 (which is relabeled as A.1.1). The alternate Required Action would apply a penalty to the core peaking factors to ensure that margin to the limits of LCO 3.2.1 and 3.2.2 is maintained with a QPTR value greater than 1.02. Additionally, Required Action A.1.2 would apply the core peaking factor penalty only for a QPTR value greater than the LCO limit of 1.02, as proposed for Required Action A.1.1.

The power reduction in Required Action A.1 is intended to ensure that the peak linear power in the core is within the safety analyses limits. The proposed alternate Required Action would also ensure that the peak linear power is within the safety analyses limits. This is accomplished by reducing the core peaking factor limits by a penalty proportional to the amount that the QPTR value exceeds 1.02. The magnitude of the penalty retains the 3:1 ratio from Required Action A.1 but only applies to the amount that the QPTR value exceeds 1.02 (as discussed in the proposed change to Require Action A.1 above). The penalty would be implemented by administratively decreasing the FQ(Z) and N

H F limits. This proposed Required Action directly addresses the margin to the core peaking factor LCO limits, whereas the current Required Action A.1 assumes that the core peaking factor LCO limits have been exceeded and requires a power reduction to restore the core peaking factors to within the LCO limits.

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TSTF-607, Rev. 0 Page 7 Current Required Action A.1 is retained and new proposed Required Action A.1.2 will be joined with an "OR". Including two acceptable Required Actions provides operational flexibility, and ensures that operation is within the assumptions in the safety analysis. The same 3% penalty will be used consistent with the current power reduction to ensure the same level of remedial action is implemented when the QPTR value is greater than the LCO limit of 1.02.

In the NRC safety evaluation for PWROG-22021-P-A/NP-A, Section 3.3, the NRC staff found that the proposed changes to the Required Actions of TS 3.2.4 are acceptable because when the LCO is not met, the TS will continue to require the plant operators to reduce power to less than or equal to 50% (i.e., to exit the LCO 3.2.4 Applicability) or follow any remedial action permitted by the TS until the LCO can be met. In Section 3.4.4 of the safety evaluation, the NRC staff also noted that the safety analyses are based on the TS initial conditions of the core peaking factors, FQ(Z) and N

H F, and these core peaking factors are multiped by the core power to determine the initial power density. Current LCO 3.2.4 Required Action A.1 requires thermal power to be reduced by 3% from the RTP for every 1% that QPTR exceeds 1.00. The proposed change to Required Action A.1 would require thermal power to be reduced by 3% from RTP for every 1% that QPTR exceeds 1.02. A 3% reduction in thermal power will result in a power density reduction of 3% or more. However, a reduction of 3% in the core peaking factor limits allows an opportunity to confirm that the existing power density is acceptable by comparing the peaking factors to the limits that were proportionally reduced to account for operating above the QPTR limit of 1.02. If the peaking factors are less than the reduced peaking factor limits, the core power distribution is bounded by the safety analyses. This reduction of 3% in the core peaking factor limits would result in a confirmation of acceptable power densities assumed as initial conditions in the safety analyses, thereby providing similar protection as reducing the thermal power.

3.4. Justification for Revising the 12 Hour Frequency for SR 3.2.4.2 One aspect of the proposed change to TS 3.2.4 is to delete SR 3.2.4.2 and incorporate it into SR 3.2.4.1 as an additional Frequency.

QPTR is determined using the four NIS PR channels periodically in accordance with SR 3.2.4.1.

If one NIS PR channel is inoperable, SR 3.2.4.1 permits using the remaining three channels to calculate the QPTR if thermal power is less than or equal to 75% RTP. If one NIS PR channel is unavailable and thermal power is greater than 75% RTP, SR 3.2.4.2 requires determining the QPTR using the movable incore detector system. (Some plants' TS permit using a PDMS to determine QPTR instead of the movable incore detector system.) Under the proposed change, the monitoring required by SR 3.2.4.1 and SR 3.2.4.2 is combined since both require a periodic verification that the QPTR is within its limit.

In lieu of the SR 3.2.4.2 requirement to determine QPTR using the movable incore detector system every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , a new Frequency is added to SR 3.2.4.1. The new Frequency requires a verification of the QPTR within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months following any rod motion of 12 steps or greater when the associated rod position indication is inoperable. This additional testing is only required if thermal power is greater than 75% RTP and if one or more PR excore channels are unavailable.

In order for the QPTR to change, the radial power distribution must change asymmetrically. The most likely cause of an asymmetric radial flux distribution is a dropped or misaligned control DRAFT

TSTF-607, Rev. 0 Page 8 rod. The rod position indication system provides the best indication of a dropped or misaligned control rod. However, if the control rod position indication system is inoperable, the QPTR determined using the movable incore detector system (or PDMS, if applicable) provides an indication of the effect of a dropped or misaligned rod on the radial power distribution.

In addition, the wording of SR 3.2.4.1 is simplified to verify that the QPTR is within its limit.

Note 1 of SR 3.2.4.1 is reworded for clarification, and Note 2 is added to allow the use of the movable incore detector system (or PDMS, if applicable) to determine the QPTR.

In the NRC safety evaluation for PWROG-22021-P-A/NP-A, Section 3.5, the NRC staff found that the consolidated SR is acceptable because it would continue to provide assurance that the necessary quality of systems and components is maintained, such that facility operation will be within safety limits, and that the LCOs will be met.

3.5. Delete Required Actions D.1.2, D.2.1 and D.2.2 in Technical Specification 3.3.1 One aspect of the proposed change is to eliminate TS 3.3.1, Required Actions D.1.2, D.2.1, and D.2.2, which are duplicative of the intent of SR 3.2.4.2. Only Required Actions associated with the Reactor Trip System Instrumentation are retained for Condition D of TS 3.3.1. The need to perform a verification of the QPTR when one PR channel is inoperable is addressed by TS 3.2.4, and does not need to be duplicated in TS 3.3.1.

Under the proposed change, SR 3.2.4.1 and SR 3.2.4.2 are combined and provide requirements for determining QPTR when one or more Power Range Neutron Flux - High channels are unavailable. Required Actions D.1.1 and D.2.1 both require placing the inoperable channel in trip. Since Required Action D.1.1 is retained, Required Action D.2.1 is not needed and is removed. Required Actions D.1.2 and D.2.2 provide the option to reduce thermal power to less than 75% RTP or to perform SR 3.2.4.2. However, if a PR channel is unavailable and thermal power is 75% or greater, SR 3.2.4.1 must be performed. If the SR is not performed, thermal power must be reduced to less than 75% RTP. As a result, the proposed SR and the TS 3.3.1 Actions are duplicative and the TS 3.3.1 Actions are removed.

In the NRC safety evaluation for PWROG-22021-P-A/NP-A, Section 3.6, the NRC staff found that the Required Actions of TS 3.3.1 are acceptable because when the LCO is not met, the TS will continue to require plant operators to shut down the reactor or follow any remedial action permitted by the TS until the LCO can be met.

3.6. Changes Not Discussed in PWROG-22021 PWROG-22021-P-A/NP-A, Section 6.2, states that after the reduction in the core peaking factor limits in accordance with the proposed Required Action A.1.2, Required Actions A.2 through A.6 are required to be performed, which includes verification that the core peaking factors are within their limits and an incore-excore calibration is performed to normalize the QPTR.

The Completion Times of Required Actions A.3, A.4, A.5, and A.6 refer to a thermal power reduction per Required Action A.1 or a thermal power increase above the limit of Required Action A.1. The PWROG-22021-P-A/NP-A, Appendix A, sample TS markups did not revise the Completion Times of Required Actions A.3, A.4, A.5 and A.6 to reflect the new option to DRAFT

TSTF-607, Rev. 0 Page 9 reduce the core peaking factor limits instead of reducing thermal power. Therefore, the following changes are made to the TS 3.2.4 Required Actions to be consistent with Section 6.2 of PWROG-22021-P-A/NP-A:

The Required Action A.3, "Perform SR 3.2.1.1, SR 3.2.1.2, and SR 3.2.2.1," Completion Time of "24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after achieving equilibrium conditions from a THERMAL POWER reduction per Required Action A.1," is revised to reference Required Action A.1.1. A new Completion Time, joined by a logical OR, is added, which states, "24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after reducing FQ(Z) and N

H F limits per Required Action A.1.2." This change ensures the SRs are performed within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months as intended whether Required Action A.1.1 or A.1.2 is applied.

The Required Action A.4, "Reevaluate safety analyses and confirm results remain valid for duration of operation under this condition," Completion Time of,"Prior to increasing THERMAL POWER above the limit of Required Action A.1," is revised to reference Required Action A.1.1. A new Completion Time, joined by a logical OR, is added, which states, "Prior to increasing FQ(Z) and N

H F limits above the limits of Required Action A.1.2." This ensures the Required Action is performed as intended prior to increasing the core peaking factor limits.

The Required Action A.5, "Normalize excore detectors to restore QPTR to within limit,"

Completion Time of, "Prior to increasing THERMAL POWER above the limit of Required Action A.1," is revised to reference Required Action A.1.1. A new Completion Time, joined by a logical OR, is added, which states, "Prior to increasing FQ(Z) and N

H F

limits above the limits of Required Action A.1.2." This ensures the Required Action is performed as intended prior to increasing the core peaking factor limits.

The Required Action A.6, "Perform SR 3.2.1.1, SR 3.2.1.2, and SR 3.2.2.1," Completion Time of, "Within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after achieving equilibrium conditions at RTP not to exceed 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months after increasing THERMAL POWER above the limit of Required Action A.1,"

is revised to reference Required Action A.1.1. A new Completion Time, joined by a logical OR, is added, which states, "Within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months after increasing FQ(Z) and N

H F

limits above the limits of Required Action A.1.2." The 24-hour allowance to achieve equilibrium conditions is not needed before performing the SRs because reactor power was not reduced. This ensures the core peaking factors are within their limits after normalizing the excore detectors and restoring a normal operating condition.

These changes to the Required Action Completion Times are needed to implement these Required Actions if Required Action A.1.2 is applied.

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TSTF-607, Rev. 0 Page 10 3.7. PWROG-22021 Limitations and Conditions The NRC safety evaluation imposed two limitations and conditions on the implementation of PWROG-22021-P-A/NP-A:

1.

With respect to nuclear power plants that do not use reload methodology from TR WCAP-9272-P-A, a discussion of how the allowances and uncertainties support a safety analysis with QPTR up to 1.02 is necessary, and should be included in [License Amendment Requests] implementing this TR as stated in Section 3.2 of this SE.

2 For nuclear power plants implementing the TR, a discussion and confirmation of the plants [Reactor Protection System] and [Nuclear Instrumentation] circuitry stating that they are consistent with information provided in the TR should be included as part of the

[License Amendment Request].

These limitations and conditions are incorporated into Section 2.1, "Applicability of Safety Evaluation," of the model application.

4. REGULATORY EVALUATION The regulation at Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(b) requires:

Each license authorizing operation of a utilization facility will include technical specifications. The technical specifications will be derived from the analyses and evaluation included in the safety analysis report, and amendments thereto, submitted pursuant to [10 CFR] 50.34 ["Contents of applications; technical information"]. The Commission may include such additional technical specifications as the Commission finds appropriate.

Regulation 10 CFR 50.36(c), Paragraph (2), states that when a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met. The proposed change provides a remedial action to be taken when the limiting condition for operation is not met and is in compliance with 10 CFR 50.36(c)(2).

Regulation 10 CFR 50.36(c), Paragraph (3), states that surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met. The proposed change revises the surveillance requirements while ensuring the limiting conditions for operation will be met, and is in compliance with 10 CFR 50.36(c)(3).

Per 10 CFR 50.90, whenever a holder of a license desires to amend the license, application for an amendment must be filed with the Commission, fully describing the changes desired, and following as far as applicable, the form prescribed for original applications.

DRAFT

TSTF-607, Rev. 0 Page 11 Per 10 CFR 50.92(a), in determining whether an amendment to a license will be issued to the applicant, the Commission will be guided by the considerations which govern the issuance of initial licenses to the extent applicable and appropriate.

Section IV, "The Commission Policy," of the "Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors" (58FR39132), dated July 22, 1993, states in part that improved STS have been developed and will be maintained for each NSSS owners group. The Commission Policy encourages licensees to use the improved STS as the basis for plant-specific Technical Specifications." The industry's proposal of travelers and the NRC's approval of travelers is the method used to maintain the improved STS as described in the Commission's Policy. Following NRC approval, licensees adopt travelers into their plant-specific technical specifications following the requirements of 10 CFR 50.90. Therefore, the traveler process facilitates the Commission's policy while satisfying the requirements of the applicable regulations.

The regulation at 10 CFR 50.36(a)(1) also requires the application to include a "summary statement of the bases or reasons for such specifications, other than those covering administrative controls." The proposed traveler revises the Bases to be consistent with the changes to the TS, and therefore complies with 10 CFR 50.36(a)(1).

In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the approval of the proposed change will not be inimical to the common defense and security or to the health and safety of the public.

5. REFERENCES

1.

Letter from Jim Lynde (PWR Owners Group) to U.S. NRC Document Control Desk, "Transmittal of the NRC Approved Version Topical Report PWROG-22021-P-A/NP-A, Revision 0, 'Justifications for the Proposed Changes to the Quadrant Power Tilt Ratio Technical Specification' (PA-ASC-1680 R3)," dated August 19, 2025 (ADAMS Accession No. ML25231A213).

2.

Email from Leslie Fields (NRC) to Dewey Olinski (Westinghouse), "NRC Transmittal of the Final Safety Evaluation for Pressurized Water Reactor Owners Group Topical Report (TR) PWROG22021-P, Revision 0, 'Justifications for the Proposed Changes to the Quadrant Power Tilt Ratio Technical Specification',"

dated May 29, 2025 (ADAMS Accession No. ML25148A288). (Safety evaluation ADAMS Accession No. ML25133A001.)

3.

Westinghouse Electric Corporation, Topical Report WCAP-9272-P-A, Revision 0, "Westinghouse Reload Safety Evaluation Methodology," March 1978 (ADAMS Accession No. ML051390150), and Topical Report WCAP-9273-NP-A, Revision 0, "Westinghouse Reload Safety Evaluation Methodology," March 1978 (ADAMS Accession No. ML19269B535).

DRAFT

TSTF-607, Rev. 0 Model Application DRAFT

TSTF-607, Rev. 0 Page 1

[DATE]

10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 PLANT NAME DOCKET NO. [50]-[xxx]

SUBJECT:

Application to Revise Technical Specifications to Adopt TSTF-607, "Changes to the Quadrant Power Tilt Ratio Technical Specification (PWROG-22021)"

Pursuant to 10 CFR 50.90, [LICENSEE] is submitting a request for an amendment to the Technical Specifications (TS) for [PLANT NAME, UNIT NOS.].

[LICENSEE] requests adoption of TSTF-607, "Changes to the Quadrant Power Tilt Ratio Technical Specification (PWROG-22021),"which is an NRC approved change to the Standard Technical Specifications (STS), into the [PLANT NAME, UNIT NOS] TS. TSTF-607 revises the TS requirements associated with TS 3.2.4, "Quadrant Power Tilt Ratio (QPTR)" and TS 3.3.1, "Reactor Trip System (RTS) Instrumentation."

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

[LICENSEE] requests that the amendment be reviewed under the Consolidated Line Item Improvement Process (CLIIP).

There are no regulatory commitments in this letter.

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

[In accordance with 10 CFR 50.30(b), a license amendment request must be executed in a signed original under oath or affirmation. This can be accomplished by attaching a notarized affidavit confirming the signature authority of the signatory, or by including the following statement in the cover letter: "I declare under penalty of perjury that the foregoing is true and correct.

Executed on (date)." The alternative statement is pursuant to 28 USC 1746. It does not require notarization.]

DRAFT

TSTF-607, Rev. 0 Page 2 If you should have any questions regarding this submittal, please contact [NAME, TELEPHONE NUMBER].

Sincerely,

[Name, Title]

Enclosure:

Description and Assessment Attachments: 1.

Proposed Technical Specification Changes (Mark-Up)

2.

[Revised Technical Specification Pages]

[3]. Proposed Technical Specification Bases Changes (Mark-Up) - For Information Only

[The attachments are to be provided by the licensee and are not included in the model application.]

cc:

NRC Project Manager NRC Regional Office NRC Resident Inspector State Contact DRAFT

TSTF-607, Rev. 0 Page 3 ENCLOSURE DESCRIPTION AND ASSESSMENT

1.0 DESCRIPTION

[LICENSEE] requests adoption of TSTF-607, "Changes to the Quadrant Power Tilt Ratio Technical Specification (PWROG-22021)," into the [PLANT NAME, UNIT NOS] TS.

TSTF-607 revises the TS requirements associated with TS 3.2.4, "Quadrant Power Tilt Ratio (QPTR)" and TS 3.3.1, "Reactor Trip System (RTS) Instrumentation."

2.0 ASSESSMENT

2.1 Applicability of Safety Evaluation

[LICENSEE] has reviewed the NRC safety evaluation for TSTF-607 provided to the Technical Specifications Task Force in a letter dated [DATE]. This review included the NRC staffs evaluation, as well as the information provided in TSTF-607. [LICENSEE] has concluded that the justifications presented in TSTF-607 and the safety evaluation prepared by the NRC staff are applicable to [PLANT, UNIT NOS.] and justify this amendment for the incorporation of the changes to the [PLANT] TS.

[LICENSEE] has also reviewed PWROG-22021-P-A/NP-A, Revision 0, "Justifications for the Proposed Changes to the Quadrant Power Tilt Ratio Technical Specification." This review included the NRC staff's evaluation. In accordance with Section 4.0, "Limitation and Conditions," of the NRC safety evaluation, [LICENSEE] provides the following verifications:

[The reload methodology used for [PLANT] is based on WCAP-9272-P-A.][The reload methodology used for [PLANT] is not based on WCAP-9272-P-A. [Describe the reload methodology and confirm that it has similar allowances and uncertainties to those discussed in Section 3.2 of the safety evaluation, and that the methodology supports a QPTR up to 1.02.))

((LICENSEE] confirms that the Reactor Protection System and Nuclear Instrumentation circuitry for [PLANT] is consistent with information provided in PWROG-22021-P.]

[The Reactor Protection System and Nuclear Instrumentation circuitry for [PLANT] is different from the information provided in PWROG-22021-P, but the traveler is still applicable. [Describe why the traveler is applicable.))

2.2 Variations

[LICENSEE is not proposing any variations from the TS changes described in TSTF-607 or the applicable parts of the NRC staffs safety evaluation.] [LICENSEE is proposing the following variations from the TS changes described in TSTF-607 or the applicable parts of the NRC staffs safety evaluation:]

DRAFT

TSTF-607, Rev. 0 Page 4

[The [PLANT] TS permit the use of a power distribution monitoring system (PDMS) instead of the movable incore detector systems when performing SR 3.2.4.2. The use of a PDMS is retained in the proposed SR 3.2.4.1.]

[The [PLANT] TS in Section 3.2 apply limits to [FMQ(X,Y,Z)] and [

(X,Y)] instead of FQ(Z) and N

H F

. However, the traveler justification remains applicable to the proposed change.]

[The [PLANT] TS utilize different [numbering][and][titles] than the STS on which TSTF-607 was based. Specifically, [describe differences between the plant-specific TS numbering and/or titles and the TSTF-607 numbering and titles.] These differences are administrative and do not affect the applicability of TSTF-607 to the [PLANT] TS.]

[The [PLANT] TS contain requirements that differ from the STS on which TSTF-607 was based but are encompassed in the TSTF-607 justification. [Describe the differences and why TSTF-607 is still applicable.]

3.0 REGULATORY ANALYSIS

3.1 No Significant Hazards Consideration Analysis

[LICENSEE] requests adoption of TSTF-607, "Changes to the Quadrant Power Tilt Ratio Technical Specification (PWROG-22021)," which is an NRC approved change to the Standard Technical Specifications (STS), into the [PLANT NAME, UNIT NOS] TS. The proposed change revises the TS requirements associated with TS 3.2.4, "Quadrant Power Tilt Ratio (QPTR)" and TS 3.3.1, "Reactor Trip System (RTS) Instrumentation.".

[LICENSEE] has evaluated if 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 amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed change revises the TS requirements associated with the QPTR and RTS Instrumentation.

A QPTR value outside the TS LCO limit or an unavailable Power Range Neutron Flux -

High channel are not initiators of any accident previously evaluated. The actions taken when the QPTR is not within limit or a Power Range Neutron Flux - High channel is unavailable are not initiators to any accident previously evaluated. As a result, the proposed change does not significantly increase the probability of an accident previously evaluated.

The actions taken when the QPTR is not within limit or a single Power Range Neutron Flux - High channel is unavailable are not mitigating actions assumed in any previously DRAFT

TSTF-607, Rev. 0 Page 5 analyzed accident. As a result, the consequences of any previously analyzed accident are not significant 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 amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed change revises the TS requirements associated with the QPTR and RTS Instrumentation.

The proposed change only applies when the QPTR LCO limit is not met or a Power Range Neutron Flux - High channel is unavailable. The QPTR LCO limit continues to be required to be met and the Power Range Neutron Flux - High channels that provide a reactor trip continue to be required to be operable. Actions taken when a TS limit is not met or equipment is inoperable is not credited in the safety analysis and, as a result, the change to the actions are not a precursor to a new or different kind of accident, and does not initiate any new or different kinds of accidents not considered in the design and licensing bases.

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

3.

Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No The proposed change revises the TS requirements associated with the QPTR and RTS Instrumentation.

The proposed change does not change the safety function of any plant equipment and does not impact any design basis accident inputs or assumptions. The proposed change does not affect any specific values that define margin as established in each plants licensing basis.

The proposed change does not alter a design basis or safety limit (i.e., the controlling numerical value for a parameter established in the UFSAR or the license), and as a result, does not significantly reduce the margin of safety.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, [LICENSEE] 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.

DRAFT

TSTF-607, Rev. 0 Page 6 3.2 Conclusion In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

4.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

DRAFT

TSTF-607, Rev. 0 Technical Specifications Changes DRAFT

QPTR 3.2.4 Westinghouse STS 3.2.4-1 Rev. 5.0 3.2 POWER DISTRIBUTION LIMITS 3.2.4 QUADRANT POWER TILT RATIO (QPTR)

LCO 3.2.4 The QPTR shall be 1.02.

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

The QPTR limit is not required to be met following refueling until after initial performance of SR 3.3.1.6.

APPLICABILITY:

MODE 1 with THERMAL POWER > 50% RTP.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. QPTR not within limit.

A.1.1 Reduce THERMAL POWER 3% from RTP for each 1% of QPTR > 1.020.

OR A.1.2 Reduce the limits for FQ(Z) and N

H F 3% for each 1% QPTR > 1.02.

AND A.2 Determine QPTR.

AND A.3 Perform SR 3.2.1.1, SR 3.2.1.2, and SR 3.2.2.1.

AND 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months after each QPTR determination 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months after each QPTR determination Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 24 hours after achieving equilibrium conditions from a THERMAL POWER reduction per Required Action A.1.1 OR 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after reducing FQ(Z) and N

H F limits per TSTF-607, Rev. 0 DRAFT

QPTR 3.2.4 Westinghouse STS 3.2.4-2 Rev. 5.0 CONDITION REQUIRED ACTION COMPLETION TIME Required Action A.1.2 AND Once per 7 days thereafter ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME A.4 Reevaluate safety analyses and confirm results remain valid for duration of operation under this condition.

AND A.5

NOTES-------------

1. Perform Required Action A.5 only after Required Action A.4 is completed.

2. Required Action A.6 shall be completed whenever Required Action A.5 is performed.

Normalize excore detectors to restore QPTR to within limit.

AND Prior to increasing THERMAL POWER above the limit of Required Action A.1.1 OR Prior to increasing FQ(Z) and N

H F limits above the limits of Required Action A.1.2 Prior to increasing THERMAL POWER above the limit of Required Action A.1.1 OR Prior to increasing FQ(Z) and N

H F limits TSTF-607, Rev. 0 DRAFT

QPTR 3.2.4 Westinghouse STS 3.2.4-3 Rev. 5.0 A.6

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

Perform Required Action A.6 only after Required Action A.5 is completed.

Perform SR 3.2.1.1, SR 3.2.1.2, and SR 3.2.2.1.

above the limits of Required Action A.1.2 Within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after achieving equilibrium conditions at RTP not to exceed 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months after increasing THERMAL POWER above the limit of Required Action A.1.1 OR Within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months after increasing FQ(Z) and N

H F limits above the limits of Required Action A.1.2 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and associated Completion Time not met.

B.1 Reduce THERMAL POWER to 50% RTP.

4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months TSTF-607, Rev. 0 DRAFT

QPTR 3.2.4 Westinghouse STS 3.2.4-4 Rev. 5.0 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.2.4.1

NOTES-----------------------------

1. With the calibrated output of from one Power Range Neutron Flux channel unavailableinoperable and THERMAL POWER 75% RTP, the remaining three Ppower Rrange Neutron Flux channels can be used for calculating to determine QPTR.

2. SR 3.2.4.2 may be performed in lieu of this Surveillance.The moveable incore detector system can be used to determine QPTR.

Verify QPTR is within limit by calculation.

[ 7 days OR In accordance with the Surveillance Frequency Control Program ]

AND

NOTE-------

Only required to be performed if calibrated output of one Power Range Neutron Flux channel is unavailable, and THERMAL POWER > 75%

RTP.

Once within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months following any rod motion 12 steps if an associated

[digital] rod position indicator is inoperable.

TSTF-607, Rev. 0 DRAFT

QPTR 3.2.4 Westinghouse STS 3.2.4-5 Rev. 5.0 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.2.4.2

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

Not required to be performed until 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after input from one or more Power Range Neutron Flux channels are inoperable with THERMAL POWER

> 75% RTP.

Verify QPTR is within limit using the movable incore detectors.

[ 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months OR In accordance with the Surveillance Frequency Control Program ]

TSTF-607, Rev. 0 DRAFT

RTS Instrumentation 3.3.1 Westinghouse STS 3.3.1-2 Rev. 5.0 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. One Power Range Neutron Flux - High channel inoperable.

[ ------------------NOTE-------------------

The inoperable channel may be bypassed for up to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months for surveillance testing and setpoint adjustment of other channels.

REVIEWERS NOTE----------

The below Note should be used for plants with installed bypass test capability.

One channel may be bypassed for up to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months for surveillance testing and setpoint adjustment.

]

D.1.1 Place channel in trip.

AND D.1.2 Reduce THERMAL POWER to 75% RTP.

OR 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months

[OR In accordance with the Risk Informed Completion Time Program]

78 hours9.027778e-4 days 0.0217 hours 1.289683e-4 weeks 2.9679e-5 months

[OR In accordance with the Risk Informed Completion Time Program]

TSTF-607, Rev. 0 DRAFT

RTS Instrumentation 3.3.1 Westinghouse STS 3.3.1-3 Rev. 5.0 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D.2.1 Place channel in trip.

AND D.2.2

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

Only required to be performed when the Power Range Neutron Flux input to QPTR is inoperable.

Perform SR 3.2.4.2.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months

[OR In accordance with the Risk Informed Completion Time Program]

Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-1 Rev. 5.0 B 3.2 POWER DISTRIBUTION LIMITS B 3.2.4 QUADRANT POWER TILT RATIO (QPTR)

BASES BACKGROUND The QPTR limit ensures that the gross radial power distribution remains consistent with the design values used in the safety analyses. Precise radial power distribution measurements are made during startup testing, after refueling, and periodically during power operation.

The power density at any point in the core must be limited so that the fuel design criteria are maintained. Together, LCO 3.2.3, "AXIAL FLUX DIFFERENCE (AFD)," LCO 3.2.4, and LCO 3.1.6, "Control Rod Insertion Limits," provide limits on process variables that characterize and control the three dimensional power distribution of the reactor core. Control of these variables ensures that the core operates within the fuel design criteria and that the power distribution remains within the bounds used in the safety analyses.

During power operation, the QPTR is determined using the excore detectors, which are the Nuclear Instrumentation System (NIS)

Power Range Neutron Flux detectors (N-41, N-42, N-43, and N-44).

Each Power Range Neutron Flux detector has an upper and lower detector. The QPTR is the ratio of the maximum upper excore detector calibrated output to the average of the upper excore detector calibrated outputs, or the ratio of the maximum lower excore detector calibrated output to the average of the lower excore detector calibrated outputs, whichever is greater.

APPLICABLE This LCO precludes core power distributions that violate the following fuel SAFETY design criteria:

ANALYSES

a.

During a large break loss of coolant accident, the peak cladding temperature must not exceed 2200°F (Ref. 1),

b.

During a loss of forced reactor coolant flow accident, there must be at least 95% probability at the 95% confidence level (the 95/95 departure from nucleate boiling (DNB) criterion) that the hot fuel rod in the core does not experience a DNB condition,

c.

During an ejected rod accident, the energy deposition to the fuel must not exceed 280 cal/gm (Ref. 2), and

d.

The control rods must be capable of shutting down the reactor with a minimum required SDM with the highest worth control rod stuck fully withdrawn (Ref. 3).

TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-2 Rev. 5.0 The LCO limits on the AFD, the QPTR, the Heat Flux Hot Channel Factor (FQ(Z)), the Nuclear Enthalpy Rise Hot Channel Factor

)

F

(

H N

, and control bank insertion are established to preclude core power distributions that exceed the safety analyses limits.

The QPTR limits ensure that H

N F

and FQ(Z) remain below their limiting values by preventing an undetected change in the gross radial power distribution.

BASES APPLICABLE SAFETY ANALYSES (continued)

In MODE 1, the H

N F

and FQ(Z) limits must be maintained to preclude core power distributions from exceeding design limits assumed in the safety analyses.

The QPTR satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO The QPTR limit of 1.02, at which corrective action is required, provides a margin of protection for both the DNB ratio and linear heat generation rate contributing to excessive power peaks resulting from X-Y plane power tilts. A limiting QPTR of 1.02 can be tolerated before the margin for uncertainty in FQ(Z) and

)

F

(

H N

is possibly challenged.

The LCO is modified by a Note which states that the QPTR limit is not required to be met following refueling until after initial performance of SR 3.3.1.6, which calibrates the excore channels to permit an accurate determination of QPTR.

APPLICABILITY The QPTR limit must be maintained in MODE 1 with THERMAL POWER

> 50% RTP to prevent core power distributions from exceeding the design limits.

Applicability in MODE 1 50% RTP and in other MODES is not required because there is either insufficient stored energy in the fuel or insufficient energy being transferred to the reactor coolant to require the implementation of a QPTR limit on the distribution of core power. The QPTR limit in these conditions is, therefore, not important. Note that the H

N F

and FQ(Z) LCOs still apply, but allow progressively higher peaking factors at 50% RTP or lower.

ACTIONS A.1.1 and A.1.2 With the QPTR exceeding its limit, a power level reduction of 3% RTP for each 1% by which the QPTR exceeds 1.020 is a conservative tradeoff of total core power with peak linear power. The Completion Time of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months allows sufficient time to identify the cause and correct the tilt. Note that the power reduction itself may cause a change in the tilted condition.

TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-3 Rev. 5.0 The maximum allowable power level initially determined by Required Action A.1.1 may be affected by subsequent determinations of QPTR.

Increases in QPTR would require power reduction within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of QPTR determination, if necessary to comply with the decreased maximum allowable power level. Decreases in QPTR would allow increasing the maximum allowable power level and increasing power up to this revised limit.

As an alternative to reducing THERMAL POWER, Required Action A.1.2 permits reducing the core peaking factor limits, FQ(Z) and N

H F

by at least 3% for each 1% QPTR is greater than 1.02 within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

Reducing the core peaking factor limits ensures that they are bounded by the limits assumed in the safety analysis (Ref. 4).

BASES ACTIONS (continued)

A.2 After completion of Required Action A.1.1 or A.1.2, the QPTR alarm may still be in its alarmed state. As such, any additional changes in the QPTR are detected by requiring a check of the QPTR once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter. A 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Completion Time is sufficient because any additional change in QPTR would be relatively slow.

A.3 The peaking factors FQ(Z), as approximated by

)

Z

(

FC Q

and

)

Z

(

FW Q

, and H

N F

are of primary importance in ensuring that the power distribution remains consistent with the initial conditions used in the safety analyses.

Performing SRs on H

N F

and FQ(Z) within the Completion Time of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after achieving equilibrium conditions from a Thermal Power reduction per Required Action A.1.1 or after reducing the core peaking factor limits per Required Action A.1.2 ensures that these primary indicators of power distribution are within their respective limits.

Equilibrium conditions are achieved when the core is sufficiently stable at intended operating conditions to support flux mapping. A Completion Time of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after achieving equilibrium conditions from Thermal Power reduction per Required Action A.1.1 or after reducing the core peaking factor limits per Required Action A.1.2 takes into consideration the rate at which peaking factors are likely to change, and the time required to stabilize the plant and perform a flux map. If these peaking factors are not within their limits, the Required Actions of these Surveillances provide an appropriate response for the abnormal condition. If the QPTR remains above its specified limit, the peaking factor surveillances are required each 7 days thereafter to evaluate H

N F

and FQ(Z) with changes in power distribution. Relatively small changes TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-4 Rev. 5.0 are expected due to either burnup and xenon redistribution or correction of the cause for exceeding the QPTR limit.

A.4 Although H

N F

and FQ(Z) are of primary importance as initial conditions in the safety analyses, other changes in the power distribution may occur as the QPTR limit is exceeded and may have an impact on the validity of the safety analysis. A change in the power distribution can affect such reactor parameters as bank worths and peaking factors for rod BASES ACTIONS (continued) malfunction accidents. When the QPTR exceeds its limit, it does not necessarily mean a safety concern exists. It does mean that there is an indication of a change in the gross radial power distribution that requires an investigation and evaluation that is accomplished by examining the incore power distribution. Specifically, the core peaking factors and the quadrant tilt must be evaluated because they are the factors that best characterize the core power distribution. This re-evaluation is required to ensure that, before increasing THERMAL POWER to above the limit of Required Action A.1.1 or increasing the core peaking factor limits to above the limits of Required Action A.1.2, the reactor core conditions are consistent with the assumptions in the safety analyses.

A.5 If the QPTR has exceeded the 1.02 limit and a re-evaluation of the safety analysis is completed and shows that safety requirements are met, the excore detectors are normalized to restore QPTR to within limits prior to increasing THERMAL POWER to above the limit of Required Action A.1.1 or increasing the core peaking factor limits to above the limits of Required Action A.1.2. Normalization is accomplished in such a manner that the indicated QPTR following normalization is near 1.00. This is done to detect any subsequent significant changes in QPTR.

Required Action A.5 is modified by two Notes. Note 1 states that the QPTR is not restored to within limits until after the re-evaluation of the safety analysis has determined that core conditions at RTP are within the safety analysis assumptions (i.e., Required Action A.4). Note 2 states that if Required Action A.5 is performed, then Required Action A.6 shall be performed. Required Action A.5 normalizes the excore detectors to restore QPTR to within limits, which restores compliance with LCO 3.2.4.

Thus, Note 2 prevents exiting the Actions prior to completing flux mapping to verify peaking factors, per Required Action A.6. These Notes are intended to prevent any ambiguity about the required sequence of actions.

TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-5 Rev. 5.0 A.6 Once the flux tilt is restored to within limits (i.e., Required Action A.5 is performed), it is acceptable to return to full power operation and restore the core peaking factor limits. However, as an added check that the core power distribution is consistent with the safety analysis assumptions, Required Action A.6 requires verification BASES ACTIONS (continued) that FQ(Z), as approximated by

)

Z

(

FC Q

and

)

Z

(

FW Q

, and H

N F

are within their specified limits within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of achieving equilibrium conditions at RTP.

As an added precaution, if the core power does not reach equilibrium conditions at RTP within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , but is increased slowly, then the peaking factor surveillances must be performed within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months after increasing THERMAL POWER above the limit of Required Action A.1.1 or restoring the core peaking factor limits. These Completion Times are intended to allow adequate time to increase THERMAL POWER to above the limit of Required Action A.1.1 or to restore the core peaking factor limits to above the limits of Required Action A.1.2, while not permitting the core to remain with unconfirmed power distributions for extended periods of time.

Required Action A.6 is modified by a Note that states that the peaking factor surveillances may only be done after the excore detectors have been normalized to restore QPTR to within limits (i.e., Required Action A.5). The intent of this Note is to have the peaking factor surveillances performed at operating power levels, which can only be accomplished after the excore detectors are normalized to restore QPTR to within limits and the core returned to powercore peaking.

B.1 If Required Actions A.1 through A.6 are not completed within their associated Completion Times, the unit must be brought to a MODE or condition in which the requirements do not apply. To achieve this status, THERMAL POWER must be reduced to < 50% RTP within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . The allowed Completion Time of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months is reasonable, based on operating experience regarding the amount of time required to reach the reduced power level without challenging plant systems.

SURVEILLANCE SR 3.2.4.1 REQUIREMENTS SR 3.2.4.1 is modified by two Notes. Note 1 allows QPTR to be calculated determined with the calibrated output of three power Power Rrange Neutron Flux channels if THERMAL POWER is 75% RTP and TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-6 Rev. 5.0 the input from one Power Range Neutron Flux channel is unavailableinoperable.

SR 3.2.4.1 Note 2 permits the use of the movable incore detector system to determine QPTRallows performance of SR 3.2.4.2 in lieu of SR 3.2.4.1. TheA symmetric thimble flux map or full core flux map can be used to determine the generate symmetric thimble power distribution "tilt." This can be compared to a reference symmetric thimble tilt, from the most recent full core flux map, to generate an incore QPTR. Therefore, incore monitoring can be used to verify confirm that QPTR is within limits.

This Surveillance verifies that the QPTR, as indicated by the Nuclear Instrumentation System (NIS) excore channels, is within its limits. [ The Frequency of 7 days takes into account other information and alarms available to the operator in the control room.

BASES SURVEILLANCE REQUIREMENTS (continued)

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

For those causes of QPT that occur quickly (e.g., a dropped rod), there typically are other indications of abnormality that prompt a verification of core power tilt.

If the calibrated output of one Power Range Neutron Flux channel is unavailable and THERMAL POWER > 75%, QPTR must be determined using the movable incore detector system. When in this condition and control rods are moved 12 steps and the associated

[digital] rod position indication is inoperable, then QPTR must be determined within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . If one Power Range Neutron Flux channel is unavailable, excore monitoring for a portion of the reactor core becomes degraded. Large tilts are likely detected with the remaining channels, however, the capability to detect small power tilts in some quadrants is decreased. In order for the QPTR to change, the radial power distribution must change asymmetrically, increasing the power in at least one core quadrant.

The most likely cause of an asymmetric radial flux distribution is a TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-7 Rev. 5.0 dropped or misaligned control rod. Rod position indications (TS 3.1.7) provide the best indication to detect a dropped or misaligned control rod, however, if the rod position indications are unavailable, the QPTR provides an indication of the magnitude of the effect of the dropped or misaligned rod on the radial power distribution. Below 75% RTP, there is sufficient margin to the core peaking factor limits that an undetected misaligned rod would be unlikely to challenge the peaking factor limits.

SR 3.2.4.2 This Surveillance is modified by a Note, which states that it is not required until 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after the input from one or more Power Range Neutron Flux channels are inoperable and the THERMAL POWER is > 75% RTP.

With an NIS power range channel inoperable, tilt monitoring for a portion of the reactor core becomes degraded. Large tilts are likely detected with the remaining channels, but the capability for detection of small power tilts in some quadrants is decreased. [ Performing SR 3.2.4.2 at a Frequency of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months provides an accurate alternative means for ensuring that any tilt remains within its limits.

OR The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REVIEWERS NOTE-----------------------------------

Plants controlling Surveillance Frequencies under a Surveillance Frequency Control Program should utilize the appropriate Frequency description, given above, and the appropriate choice of Frequency in the Surveillance Requirement.

]

TSTF-607, Rev. 0 DRAFT

QPTR B 3.2.4 Westinghouse STS B 3.2.4-8 Rev. 5.0 BASES SURVEILLANCE REQUIREMENTS (continued)

For purposes of monitoring the QPTR when one power range channel is inoperable, the moveable incore detectors are used to confirm that the normalized symmetric power distribution is consistent with the indicated QPTR and any previous data indicating a tilt. The incore detector monitoring is performed with a full incore flux map or two sets of four thimble locations with quarter core symmetry. The two sets of four symmetric thimbles is a set of eight unique detector locations. These locations are C-8, E-5, E-11, H-3, H-13, L-5, L-11, and N-8 for three and four loop cores.

The symmetric thimble flux map can be used to generate symmetric thimble "tilt." This can be compared to a reference symmetric thimble tilt, from the most recent full core flux map, to generate an incore QPTR.

Therefore, incore monitoring of QPTR can be used to confirm that QPTR is within limits.

With one NIS channel inoperable, the indicated tilt may be changed from the value indicated with all four channels OPERABLE. To confirm that no change in tilt has actually occurred, which might cause the QPTR limit to be exceeded, the incore result may be compared against previous flux maps either using the symmetric thimbles as described above or a complete flux map. Nominally, quadrant tilt from the Surveillance should be within 2% of the tilt shown by the most recent flux map data.

REFERENCES

1.

10 CFR 50.46.

2.

Regulatory Guide 1.77, Rev [0], May 1974.

3.

10 CFR 50, Appendix A, GDC 26.

4.

PWROG-22021-P-A/NP-A, Revision 0, "Justifications for the Proposed Changes to the Quadrant Power Tilt Ratio Technical Specification."

TSTF-607, Rev. 0 DRAFT

RTS Instrumentation B 3.3.1 Westinghouse STS B 3.3.1-35 Rev. 5.0 BASES ACTIONS (continued)

D.1.1, D.1.2, D.2.1, and D.2.2 Condition D applies to the Power Range Neutron Flux - High Function.

The NIS power range detectors provide input to the Rod Control System and the SG Water Level Control System and, therefore, have a two-out-of-four trip logic. A known inoperable channel must be placed in the tripped condition. This results in a partial trip condition requiring only one-out-of-three logic for actuation. The 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months allowed to place the inoperable channel in the tripped condition is justified in WCAP-14333-P-A (Ref. 8). [Alternatively, a Completion Time can be determined in accordance with the Risk Informed Completion Time Program.]

In addition to placing the inoperable channel in the tripped condition, THERMAL POWER must be reduced to 75% RTP within 78 hours9.027778e-4 days 0.0217 hours 1.289683e-4 weeks 2.9679e-5 months [or in accordance with the Risk Informed Completion Time Program]. Reducing the power level prevents operation of the core with radial power distributions beyond the design limits. With one of the NIS power range detectors inoperable, 1/4 of the radial power distribution monitoring capability is lost.

As an alternative to the above actions, the inoperable channel can be placed in the tripped condition within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months [or in accordance with the Risk Informed Completion Time Program] and the QPTR monitored once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months as per SR 3.2.4.2, QPTR verification. Calculating QPTR every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months compensates for the lost monitoring capability due to the inoperable NIS power range channel and allows continued unit operation at power levels > 75% RTP. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Frequency is consistent with LCO 3.2.4, "QUADRANT POWER TILT RATIO (QPTR)."

[ The Required Actions have been modified by a Note that allows placing the inoperable channel in the bypass condition for up to 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months while performing routine surveillance testing of other channels. The Note also allows placing the inoperable channel in the bypass condition to allow setpoint adjustments of other channels when required to reduce the setpoint in accordance with other Technical Specifications. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months time limit is justified in Reference 8. ]

TSTF-607, Rev. 0 DRAFT

RTS Instrumentation B 3.3.1 Westinghouse STS B 3.3.1-36 Rev. 5.0 BASES ACTIONS (continued)

REVIEWERS NOTE-----------------------------------

The below text should be used for plants with installed bypass test capability:

The Required Actions are modified by a Note that allows placing one channel in bypass for 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months while performing routine surveillance testing, and setpoint adjustments when a setpoint reduction is required by other Technical Specifications. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months time limit is justified in Reference 8.

Required Action D.2.2 has been modified by a Note which only requires SR 3.2.4.2 to be performed if the Power Range Neutron Flux input to QPTR becomes inoperable. Failure of a component in the Power Range Neutron Flux Channel which renders the High Flux Trip Function inoperable may not affect the capability to monitor QPTR. As such, determining QPTR using this movable incore detectors once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months may not be necessary.

E.1 Condition E applies to the following reactor trip Functions:

Power Range Neutron Flux - Low, Overtemperature T, Overpower T, Power Range Neutron Flux - High Positive Rate, Power Range Neutron Flux - High Negative Rate, Pressurizer Pressure - High, SG Water Level - Low Low, and SG Water Level - Low coincident with Steam Flow/Feedwater Flow Mismatch.

TSTF-607, Rev. 0 DRAFT

ML25261A149

Text

Description:

Description:

Description:

SUMMARY

SUMMARY

SUBJECT:

Enclosure:

1.0 DESCRIPTION

2.0 ASSESSMENT

3.0 REGULATORY ANALYSIS

4.0 ENVIRONMENTAL CONSIDERATION

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