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Changes Related to AP1000 Gts Subsection 3.2.1, Heat Flux Hot Channel Factor
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GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 1 Advanced Passive 1000 (AP1000)

Generic Technical Specification Traveler (GTST)

Title:

Changes related to Section 3.2.1, Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology)

I.

Technical Specifications Task Force (TSTF) Travelers, Approved Since Revision 2 of STS NUREG-1431, and Used to Develop this GTST TSTF Number and

Title:

TSTF-425, Rev. 3, Relocate Surveillance Frequencies to Licensee Control - RITSTF Initiative 5b TSTF-519-T, Rev. 0: Increase Standardization in Condition and Required Action Notes STS NUREGs Affected:

TSTF-425, Rev. 3: NUREG-1430, -1431, -1432, -1433, -1434 TSTF-519, Rev. 0: NUREG-1430, -1431, -1432, -1433, -1434 NRC Approval Date:

TSTF-425, Rev. 3: 18-Mar-2009 TSTF-519, Rev. 0: Not available TSTF Classification:

TSTF-425, Rev. 3: Technical Change TSTF-519, Rev. 0: NUREG only change

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 2 II.

Reference Combined License (RCOL) Standard Departures (Std. Dep.), RCOL COL Items, and RCOL Plant-Specific Technical Specifications (PTS) Changes Used to Develop this GTST RCOL Std. Dep. Number and

Title:

None RCOL COL Item Number and

Title:

None RCOL PTS Change Number and

Title:

VEGP LAR DOC A011 Statements referring to OPDMS operable and OPDMS inoperable are revised respectively to refer to OPDMS monitoring parameters and OPDMS not monitoring parameters.

VEGP LAR DOC A018 SR 3.2.1.1 and SR 3.2.1.2 are revised to split each of them into two Surveillances.

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 3 III.

Comments on Relations Among TSTFs, RCOL Std. Dep., RCOL COL Items, and RCOL PTS Changes This section discusses the considered changes that are: (1) applicable to operating reactor designs, but not to the AP1000 design; (2) already incorporated in the GTS; or (3) superseded by another change.

TSTF-519-T has already been implemented by AP1000 and the VEGP TS. No change was needed for TSTF-519-T.

TSTF-425 is deferred for future consideration.

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 4 IV.

Additional Changes Proposed as Part of this GTST (modifications proposed by NRC staff and/or clear editorial changes or deviations identified by preparer of GTST)

APOG Recommended Changes to Improve the Bases A correction is recommended in the Actions section of the Bases consistent with the TS requirement.

An editorial correction is recommended in the LCO section of the Bases for clarity.

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 5 V.

Applicability Affected Generic Technical Specifications and Bases:

Section 3.2.1, Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology)

Changes to the Generic Technical Specifications and Bases:

The APPLICABILITY statement is revised replacing OPDMS inoperable with OPDMS not monitoring parameters. (DOC A011)

Surveillance Requirements are redefined. Two current Surveillances are modified and the new Surveillance Requirements consist of four Surveillances. Notes specific to the Surveillances are defined. (DOC A012)

An editorial change is made in the LCO section of the Bases. (APOG Comment)

A correction is made in the Actions A.2 section of the Bases. (APOG Comment)

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 6 VI.

Traveler Information Description of TSTF changes:

TSTF-519-T provides consistency in the placement of Notes in Condition and Required Action Column in the ACTIONS Table. Specifically, Notes in the Condition Column should appear to the right of the Condition designator, not above the Condition designator. Notes that apply to all Required Actions of a Condition are placed above the first Required Action and are full width of the Column. Notes that apply to a single Required Action are placed to the right of the designator of the Required Action.

Rationale for TSTF changes:

The changes are editorial corrections and not technical changes.

The change to the Required Action Note placement avoids a potential error-prone situation. If a Condition has a single Required Action and a Note located above the Required Action, that Note will apply to any Required Action added to the Condition in the future. By placing a Note to the right of the Required Action designator, it requires a conscious decision by the licensee to apply the existing Note to the new Required Action.

Description of changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:

VEGP LAR DOC A011:

Various statements referring to OPDMS OPERABLE are revised to refer to OPDMS monitoring parameters. Various statements referring to OPDMS inoperable are revised to refer to OPDMS not monitoring parameters.

VEGP LAR DOC A018:

TS 3.2.1, Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology), SR 3.2.1.1 and SR 3.2.1.2 each have three Frequencies, which require verification of FQ W(Z) [for SR 3.2.1.1] and FQ C(Z) [for SR 3.2.1.2] limits:

Once after each refueling prior to THERMAL POWER exceeding 75% RTP AND Once within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which [FQ C(Z)][ FQ W(Z)] was last verified

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 7 AND 31 effective full power days (EFPD) thereafter SR 3.2.1.1 and SR 3.2.1.2 are revised to split each of them into two Surveillances; one pair of SRs with the Once after each refueling prior to THERMAL POWER exceeding 75% RTP Frequency (i.e., new SR 3.2.1.1 and SR 3.2.1.2), and the remaining pair of SRs with the remaining two Frequencies (i.e., new SR 3.2.1.3 and SR 3.2.1.4).

Currently, there are two Notes applicable to both SR 3.2.1.1 and SR 3.2.1.2, which state:

1.

During power escalation at the beginning of each cycle, THERMAL POWER may be increased until a power level for extended operation has been achieved at which a power distribution map is obtained.

2.

If the OPDMS becomes inoperable while in MODE 1 these surveillances must be performed within 31 days of the last verification of OPDMS parameters.

The existing Note 1 is replaced as follows: the new SRs 3.2.1.1 and 3.2.1.2 with the Once after each refueling prior to THERMAL POWER exceeding 75% RTP Frequency, will include a new Note stating:

Not required to be performed if OPDMS was monitoring parameters upon exceeding 75% RTP.

Existing Note 2 will not be applied to new SRs 3.2.1.1 and 3.2.1.2, and existing Note 1 will not be applied to new SRs 3.2.1.3 and 3.2.1.4. However, for new SRs 3.2.1.3 and 3.2.1.4, existing Note 2 is reworded as SR 3.2.1.3 Note and SR 3.2.1.4 Note 1 stating:

Not required to be performed until 31 days after the last verification of OPDMS parameters.

Current SR 3.2.1.2 Note will not be included with new SR 3.2.1.2 and is renumbered as Note 2 in new SR 3.2.1.4.

Rationale for changes in RCOL Std. Dep., RCOL COL Item(s), and RCOL PTS Changes:

VEGP LAR DOC A011:

The On-Line Power Distribution Monitoring System (OPDMS) is not safety related and does not have a safety function. OPDMS is an advanced core monitoring and support package. With OPDMS operating, the power distribution parameters are continuously computed and displayed, and compared against their limit. The TS definition of Operable is applied to assure a system is capable of performing its specified safety function(s). As such the use of the defined term is not appropriate for the OPDMS. Additionally, there is no requirement for maintaining its non-safety related capability.

The online monitoring capability of OPDMS is utilized when complying with TS 3.2.5, OPDMS-Monitored Parameters. The parameters required to meet LCO 3.2.5 are only applicable when OPDMS is providing the monitoring for compliance with the applicable limits. When OPDMS is not being utilized, the limits of TS 3.1.6, 3.2.1, 3.2.2, 3.2.3, and 3.2.4 are applicable (note that certain Actions of TS 3.1.4 also impose requirements of TS 3.2.1 and 3.2.2 when OPDMS is not being utilized). The current use of OPERABLE (and inoperable) in referencing whether

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 8 OPDMS is being utilized, is misleading and is more appropriately revised to monitoring (and not monitoring).

VEGP LAR DOC A018:

TS 3.2.1, and therefore its SRs, is currently only applicable when the Online Power Distribution Monitoring System (OPDMS) is inoperable (revised to not monitoring parameters). (Note that references to OPDMS OPERABLE and inoperable throughout TS are revised to monitoring parameters and not monitoring parameters, respectively, as discussed in DOC A011.)

In accordance with SR 3.0.1, SRs are required to be met when the TS is applicable, i.e.,

immediately on OPDMS not monitoring parameters, and failure to perform a Surveillance within the specified Frequency is a failure to meet the LCO and would constitute a violation of SR 3.0.4. As such, the TS 3.2.1 SRs must be stated such that they are required to be performed only after an appropriate allowance when OPDMS was not monitoring and/or is no longer monitoring parameters.

The Surveillance Frequency Once after each refueling prior to THERMAL POWER exceeding 75% RTP for proposed SRs 3.2.1.1 and 3.2.1.2 is associated solely with the beginning of cycle startup after a refueling and would have a unique exception related to whether OPDMS was monitoring parameters or not. As described in the current TS 3.2.1 Bases, the existing SRs Note 1 applies to the situation where the OPDMS is inoperable at the beginning of cycle startup after a refueling allowing an equilibrium power level to be achieved at which time a power distribution map can be obtained. The proposed replacement Note will exclude the initial post-refueling flux map and verification of FQ(Z) when that startup was performed with OPDMS monitoring its associated parameters as power is increased above 75% RTP. If OPDMS ceases to monitor parameters at some point after initial power escalation above 75%, it would be inappropriate to consider this SR not performed and therefore the LCO not met. Appropriate core monitoring was provided for the transition above 75% RTP, and further FQ(Z) monitoring is adequately addressed by proposed SRs 3.2.1.3 and 3.2.1.4. This is an explicit clarification of the intent of the current stated Frequency and the current SR Note 1 as outlined in the Bases.

Therefore, this change is deemed an administrative clarification with no resultant technical change to the current TS.

The Frequencies that are split out into proposed SRs 3.2.1.3 and 3.2.1.4 relate to the periodic verification that is appropriate without the continuous monitoring capability of OPDMS.

Additionally, verification is required following a power increase and subsequent equilibrium condition which is more than 10% RTP above the prior verification. This will ensure that FQ(Z) is verified as soon as RTP (or any other level for extended operation) is achieved. The current SR Note 2 provides an explicit 31-day exception to performing the Surveillance (i.e., for not meeting these Frequencies) when OPDMS is initially not monitoring parameters. The rewording of this allowance in revised SR 3.2.1.3 Note and SR 3.2.1.4 Note 1 provides the same intent, but is worded in accordance with TSTF-GG-05-01, subsection 4.1.7.f and 4.1.7.g. Therefore, this change is deemed an administrative clarification with no resultant technical change to the current TS.

Current SR 3.2.1.2 Note details requirements when one measurement has increased over a previous measurement. Since the Frequency of Once after each refueling prior to THERMAL POWER exceeding 75% RTP is a first performance requirement, there would be no previous measurement to compare to. As such, not including the current SR 3.2.1.2 Note in the split out revised SRs 3.2.1.1 and 3.2.1.2, which contain the first performance Frequency, will not be included with new SR 3.2.1.2.

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 9 Note that certain Required Actions specify performance of current SR 3.2.1.1 and SR 3.2.1.2 (i.e., TS 3.1.4 Required Action B.2.4; TS 3.2.1 Required Action A.4; TS 3.2.1 Required Action B.4; TS 3.2.4 Required Action A.3; and TS 3.2.4 Required Action A.6). Current SR 3.2.1.1 and SR 3.2.2 require verification of FQ C (Z) and FQ W (Z), respectively. These verifications are consistent with the new TS 3.2.1 SRs. The new SR 3.2.1.3 and SR 3.2.1.4 similarly require the same verifications. The differences being associated with performance timing Frequencies and Notes; however, when directed by other Required Actions, those Frequencies are not applicable. Continuing to specify only new SR 3.2.1.1 and SR 3.2.1.2 in these Required Actions retains the current intent and requirements.

These changes are designated as administrative changes and are acceptable because they do not result in technical changes to the TS.

Description of additional changes proposed by NRC staff/preparer of GTST:

The following editorial change is made in the LCO section of the Bases:

The actual values of CFQ are given in the COLR; however, CFQ is normally a number on the order of 2.60. For the AP1000, tThe normalized...

The following correction is made in the Actions section of the Bases, under heading A.2:

... Power Range Neutron Flux - High trip setpoint reduction within 8 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months of the FQ C(Z) determination, if necessary to comply with the decreased maximum allowable...

Rationale for additional changes proposed by NRC staff/preparer of GTST:

The change in the Actions section of the Bases, under heading A.2, is a correction. This corrects an obvious misstatement and makes the Bases discussion consistent with the requirements reducing the potential for misunderstanding and misapplication.

The editorial correction in the LCO section of the Bases provides clarity.

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 10 VII. GTST Safety Evaluation Technical Analysis:

Replacing OPDMS inoperable with OPDMS not monitoring parameters The Applicability in the Specifications and the Bases for this Section are revised to state OPDMS is not monitoring parameters replacing OPDMS is inoperable consistent with the changes made in TS 3.2.5, OPDMS -Monitoring Parameters.

In TS, the term Operable is applied to assure that a system is capable of performing its specified safety function(s). OPDMS is not safety related and does not have a safety function. It is a core monitoring and support package. As described, when OPDMS is operating, the power distribution parameters are continuously computed and displayed, and compared against their limit. It is, therefore, appropriate to use the terms OPDMS is monitoring parameters and OPDMS is not monitoring parameters.

Changes to the Surveillance Requirements SR 3.2.1.1 and SR 3.2.1.2 are restructured into four SRs - SR 3.2.1.1, SR 3.2.1.2, SR 3.2.1.3, and SR 3.2.1.4.

The Surveillance Frequency Once after each refueling prior to THERMAL POWER exceeding 75% RTP for proposed SRs 3.2.1.1 and 3.2.1.2 is associated solely with the beginning of cycle startup after a refueling and would have a unique exception related to whether OPDMS was monitoring parameters or not.

The Frequencies that are split out into proposed SRs 3.2.1.3 and 3.2.1.4 relate to the periodic verification that is appropriate without the continuous monitoring capability of OPDMS.

Additionally, verification is required following a power increase and subsequent equilibrium condition which is more than 10% RTP above the prior verification. This will ensure that FQ(Z) is verified as soon as RTP (or any other level for extended operation) is achieved. The current SR Note 2 provides an explicit 31-day exception to performing the Surveillance (i.e., for not meeting these Frequencies) when OPDMS is initially not monitoring parameters. The rewording of this allowance in revised SR 3.2.1.3 Note and SR 3.2.1.4 Note 1 provides the same intent, but is worded in accordance with TSTF-GG-05-01, subsection 4.1.7.f and 4.1.7.g.

Thus, the restructuring of the SRs into four SRs provides a better way to present the requirements. It accomplishes the following objectives:

(1) SRs are defined considering when the Surveillance is to be conducted, providing clear guidance and focus for the operators, (2) Frequencies are specifically stated instead of being surmised from the Notes, and (3) SRs when OPDMS is monitoring parameters and when it is not are clearly stated.

These changes are not technical and can be considered administrative. These changes are acceptable as they will be easier to understand and implement by the operators.

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 11 Remaining Changes The remaining changes are editorial, clarifying, grammatical, or otherwise considered administrative. These changes do not affect the technical content, but improve the readability, implementation, and understanding of the requirements, and are therefore acceptable.

Having found that this GTSTs proposed changes to the GTS and Bases are acceptable, the NRC staff concludes that AP1000 STS Subsection 3.2.1 is an acceptable model Specification for the AP1000 standard reactor design.

References to Previous NRC Safety Evaluation Reports (SERs):

None

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 12 VIII. Review Information Evaluator Comments:

None Pranab K. Samanta Brookhaven National Laboratory 631-344-4948 samanta@bnl.gov Review Information:

Availability for public review and comment on Revision 0 of this traveler approved by NRC staff on 4/7/2014.

APOG Comments (Ref. 7) and Resolutions

1.

(Internal #95) 3.2.01, Pg. 10, The first sentence in the second paragraph of the Technical Analysis in this GTST was deleted since sufficient information is provided in the rest of the paragraph to justify the change.

2.

(Internal #96) 3.2.01, Pg. 41, An editorial change was made in the LCO section of the Bases for clarity.

3.

(Internal #97) 3.2.01, Pg. 43, A correction was made in the Actions section, under heading A.2, of the Bases consistent with the requirements.

NRC Final Approval Date: 6/25/2015 NRC

Contact:

T. R. Tjader United States Nuclear Regulatory Commission 301-415-1187 Theodore.Tjader@nrc.gov

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 13 IX.

Evaluator Comments for Consideration in Finalizing Technical Specifications and Bases None

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 14 X.

References Used in GTST

1.

AP1000 DCD, Revision 19, Section 16, Technical Specifications, June 2011 (ML11171A500).

2.

Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Unit 3 and 4, Technical Specifications Upgrade License Amendment Request, February 24, 2011 (ML12065A057).

3.

TSTF-GG-05-01, Technical Specification Task Force (TSTF) Writer's Guide for Plant-Specific Improved Technical Specifications, Revision 1.

4.

RAI Letter No. 01 Related to License Amendment Request (LAR)12-002 for the Vogtle Electric Generating Plant, Units 3 and 4 Combined Licenses, September 7, 2012 (ML12251A355).

5. Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Units 3 and 4, Response to Request for Additional Information Letter No. 01 Related to License Amendment Request LAR-12-002, ND-12-2015, October 04, 2012 (ML12286A363 and ML12286A360).

6.

NRC Safety Evaluation (SE) for Amendment No. 13 to Combined License (COL) No. NPF-91 for Vogtle Electric Generating Plant (VEGP) Unit 3, and Amendment No. 13 to COL No.

NPF-92 for VEGP Unit 4, September 9, 2013 (ADAMS Package Accession No. ML13238A337), which contains:

ML13238A355, Cover Letter - Issuance of License Amendment No. 13 for Vogtle Units 3 and 4 (LAR 12-002).

ML13238A359, - Amendment No. 13 to COL No. NPF-91 ML13239A256, - Amendment No. 13 to COL No. NPF-92 ML13239A284, - Revised plant-specific TS pages (Attachment to Amendment No. 13)

ML13239A287, - Safety Evaluation (SE), and Attachment 1 - Acronyms ML13239A288, SE Attachment 2 - Table A - Administrative Changes ML13239A319, SE Attachment 3 - Table M - More Restrictive Changes ML13239A333, SE Attachment 4 - Table R - Relocated Specifications ML13239A331, SE Attachment 5 - Table D - Detail Removed Changes ML13239A316, SE Attachment 6 - Table L - Less Restrictive Changes The following documents were subsequently issued to correct an administrative error in :

ML13277A616, Letter - Correction To The Attachment (Replacement Pages) - Vogtle Electric Generating Plant Units 3 and 4-Issuance of Amendment Re:

Technical Specifications Upgrade (LAR 12-002) (TAC No. RP9402)

ML13277A637, - Revised plant-specific TS pages (Attachment to Amendment No. 13) (corrected)

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 15

7.

APOG-2014-008, APOG (AP1000 Utilities) Comments on AP1000 Standardized Technical Specifications (STS) Generic Technical Specification Travelers (GTSTs), Docket ID NRC-2014-0147, September 22, 2014 (ML14265A493).

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 16 XI.

MARKUP of the Applicable GTS Subsection for Preparation of the STS NUREG The entire section of the Specifications and the Bases associated with this GTST is presented next.

Changes to the Specifications and Bases are denoted as follows: Deleted portions are marked in strikethrough red font, and inserted portions in bold blue font.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 17 3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology)

LCO 3.2.1 FQ(Z), as approximated by FQ C(Z) and FQ W(Z), shall be within the limits specified in the COLR.

APPLICABILITY:

MODE 1 with On-line Power Distribution Monitoring System (OPDMS) not monitoring parametersinoperable.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. ------------NOTE------------

Required Action A.4 shall be completed whenever this Condition is entered.

FQ C(Z) not within limit.

A.1 Reduce THERMAL POWER 1% RTP for each 1% FQ C(Z) exceeds limit.

AND 15 minutes after each FQ C(Z) determination A.2 Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1%

FQ C(Z) exceeds limit.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months after each FQ C(Z) determination A.3 Reduce Overpower T trip setpoints 1% for each 1%

FQ C(Z) exceeds limit.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months after each FQ C(Z) determination A.4 Perform SR 3.2.1.1 and SR 3.2.1.2.

Prior to increasing THERMAL POWER above the limit of Required Action A.1

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 18 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. ------------NOTE------------

Required Action B.4 shall be completed whenever this Condition is entered.

FQ W(Z) not within limits.

B.1 Reduce AFD limits 1% for each 1% FQ W(Z) exceeds limit.

AND 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months B.2 Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1%

that the maximum allowable power of the AFD limits is reduced.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.3 Reduce Overpower T trip setpoints 1% for each 1%

that the maximum allowable power of the AFD limits is reduced.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.4 Perform SR 3.2.1.1 and SR 3.2.1.2.

Prior to increasing THERMAL POWER above the maximum allowable power of the AFD limits C. Required Action and associated Completion Time not met.

C.1 Be in MODE 2.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-3 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 19 SURVEILLANCE REQUIREMENTS

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

1.

During power escalation at the beginning of each cycle, THERMAL POWER may be increased until a power level for extended operation has been achieved at which a power distribution map is obtained.

2.

If the OPDMS becomes inoperable while in MODE 1 these surveillances must be performed within 31 days of the last verification of OPDMS parameters.

SURVEILLANCE FREQUENCY SR 3.2.1.1

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

Not required to be performed if OPDMS was monitoring parameters upon exceeding 75% RTP.

Verify FQC (Z) within limit.

Once after each refueling prior to THERMAL POWER exceeding 75%

RTP AND Once within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which FQC (Z) was last verified AND 31 effective full power days (EFPD) thereafter Verify FQ C(Z) within limit.

Once after each refueling prior to THERMAL POWER exceeding 75% RTP

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-4 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 20 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.2.1.2

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

Not required to be performed if OPDMS was monitoring parameters upon exceeding 75% RTP.

Verify FQ W(Z) within limits.

Once after each refueling prior to THERMAL POWER exceeding 75% RTP SR 3.2.1.3

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

Not required to be performed until 31 days after the last verification of OPDMS parameters.

Verify FQ C(Z) within limit.

Once within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which FQ C(Z) was last verified AND 31 effective full power days (EFPD) thereafter

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-5 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 21 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.2.1.4

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

1. Not required to be performed until 31 days after the last verification of OPDMS parameters.

2. If FQ W(Z) measurements indicate maximum over zFQ C(Z) has increased since the previous evaluation of FQ C(Z):

a. Increase FQ W(Z) by the greater of a factor of 1.02 or by an appropriate factor specified in the COLR and reverify FQ W(Z) is within limits; or

b. Repeat SR 3.2.1.42 once per 7 EFPD until two successive flux maps indicate maximum over zFQ C(Z) has not increased.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-6 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 22 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.2.1.4 (continued)

Verify FQ W(Z) within limits.

Once after each refueling prior to THERMAL POWER exceeding 75%

RTP AND Once within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which FQ W(Z) was last verified AND 31 EFPD thereafter

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-1 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 23 B 3.2 POWER DISTRIBUTION LIMITS B 3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology)

BASES BACKGROUND The purpose of the limits on the values of FQ(Z) is to limit the local (i.e.,

pellet) peak power density. The value of FQ(Z) varies along the axial height (Z) of the core.

FQ(Z) is defined as the maximum local fuel rod linear power density divided by the average fuel rod linear power density, assuming nominal fuel pellet and fuel rod dimensions. Therefore, FQ(Z) is a measure of the peak fuel pellet power within the reactor core.

During power operation with the On-line Power Distribution Monitoring System (OPDMS) not monitoring parametersinoperable, the global power distribution is limited by LCO 3.2.3, AXIAL FLUX DIFFERENCE (AFD), and LCO 3.2.4, QUADRANT POWER TILT RATIO (QPTR),

which are directly and continuously measured process variables. These LCOs along with LCO 3.1.6, Control Bank Insertion Limits, maintain the core limits on power distributions on a continuous basis.

FQ(Z) varies with fuel loading patterns, control bank insertion, fuel burnup, and changes in axial power distribution.

With the OPDMS monitoring parametersOPERABLE, peak linear power density kw/ft (Z) (which is proportional to FQ(Z)) is measured continuously. With the OPDMS not monitoring parametersinoperable, FQ(Z) is measured periodically using the incore detector system. These measurements are generally taken with the core at or near steady state conditions.

With the measured three dimensional power distributions, it is possible to derive a measured value for FQ(Z) with the OPDMS not monitoring parametersinoperable. However, because this value represents a steady state condition, it does not include the variations in the value of FQ(Z) which are present during a nonequilibrium situation such as load following.

To account for these possible variations, the steady state value of FQ(Z) is adjusted by an elevation dependent factor to account for the calculated worst case transient conditions.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-2 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 24 BASES BACKGROUND (continued)

Core monitoring and control under non-equilibrium conditions and the OPDMS not monitoring parametersinoperable are accomplished by operating the core within the limits of the appropriate LCOs, including the limits on AFD, QPTR, and control rod insertion.

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

a.

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

b.

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

Limits on FQ(Z) ensure that the value of the initial total peaking factor assumed in the accident analyses remains valid. Other criteria must also be met (e.g., maximum cladding oxidation, maximum hydrogen generation, coolable geometry, and long term cooling). However, the peak cladding temperature is typically most limiting.

FQ(Z) limits assumed in the LOCA analysis are typically limiting (i.e.,

lower than) relative to the FQ(Z) assumed in safety analyses for other postulated accidents. Therefore, this LCO provides conservative limits for other postulated accidents.

FQ(Z) satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-3 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 25 BASES LCO The Heat Flux Hot Channel Factor, FQ(Z), shall be limited by the following relationships:

FQ(Z) CFQ / P for P > 0.5 FQ(Z) CFQ / 0.5 for P 0.5 where: CFQ is the FQ(Z) limit at RTP provided in the COLR, P = THERMAL POWER / RTP The actual values of CFQ are given in the COLR; however, CFQ is normally a number on the order of 2.60. For the AP1000, tThe normalized FQ(Z) as a function of core height is 1.0.

For RAOC operation, FQ(Z) is approximated by FQ C(Z) and FQ W(Z). Thus, both FQ C(Z) and FQ W(Z) must meet the preceding limits on FQ(Z).

An FQ C(Z) evaluation requires obtaining an incore flux map in MODE 1.

From the incore flux map results the measured value of FQ(Z), called FQ M(Z) is obtained. Then, FQ C(Z) = FQ M(Z)

F Q MU(Z) where F Q MU(Z) is a factor that accounts for fuel manufacturing tolerances and flux map measurement uncertainty. F Q MU(Z) is provided in the COLR.

FQ C(Z) is an excellent approximation for FQ(Z) when the reactor is at the steady state power at which the incore flux map was taken.

The expression for FQ W(Z) is:

FQ W(Z) = FQ C(Z)

W(Z) where W(Z) is a cycle-dependent function that accounts for power distribution transients encountered during normal operation. W(Z) is included in the COLR.

The FQ(Z) limits define limiting values for core power peaking that precludes peak cladding temperatures above 2200°F during either a large or small break LOCA.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-4 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 26 BASES LCO (continued)

This LCO requires operation within the bounds assumed in the safety analyses. Calculations are performed in the core design process to confirm that the core can be controlled in such a manner during operation that it can stay within the LOCA FQ(Z) limits. If FQ(Z) cannot be maintained within the LCO limits, reduction of the core power is required and if FQ W(Z) cannot be maintained within LCO limits, reduction of the AFD limits will also result in a reduction of the core power.

Violating the LCO limits for FQ(Z) may result in an unanalyzed condition while FQ(Z) is outside its specified limits.

APPLICABILITY When the OPDMS is not monitoring parametersinoperable and core power distribution parameters cannot be continuously monitored, it is necessary to determine FQ(Z) on a periodic basis. Furthermore, the FQ(Z) limits must be maintained in MODE 1 to prevent core power distributions from exceeding the limits assumed in the safety analyses.

Applicability 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 a limit on the distribution of core power.

ACTIONS A.1 Reducing THERMAL POWER by 1% of RTP for each 1% by which FQ C(Z) exceeds its limit, maintains an acceptable absolute power density.

FQ C(Z) is FQ M(Z) multiplied by a factor accounting for fuel manufacturing tolerances and flux map measurement uncertainties. FQ M(Z) is the measured value of FQ(Z). The Completion Time of 15 minutes provides an acceptable time to reduce power in an orderly manner without allowing the plant to remain in an unacceptable condition for an extended period of time. The maximum allowable power level initially determined by Required Action A.1 may be affected by subsequent determinations of FQ C(Z) and would require power reductions within 15 minutes of the FQ C(Z) determination, if necessary to comply with the decreased maximum allowable power level. Decreases in FQ C(Z) would allow increasing the maximum allowable power level and increasing power up to this revised limit.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-5 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 27 BASES ACTIONS (continued)

A.2 A reduction of the Power Range Neutron Flux - High Trip setpoints by 1% for each 1% by which FQ C(Z) exceeds its limit is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period and the prompt reduction in THERMAL POWER in accordance with Required Action A.1. The maximum allowable Power Range Neutron Flux - High trip setpoints initially determined by Required Action A.2 may be affected by subsequent determinations of FQ C(Z) and would require Power Range Neutron Flux - High trip setpoint reductions within 872 hours0.0101 days 0.242 hours 0.00144 weeks 3.31796e-4 months of the FQ C(Z) determination, if necessary to comply with the decreased maximum allowable Power Range Neutron Flux - High trip setpoints. Decreases in FQ C(Z) would allow increasing the maximum allowable Power Range Neutron Flux - High trip setpoints.

A.3 Reduction in the Overpower T Trip setpoints (value of K4) by 1% for each 1% by which FQ C(Z) exceeds its limit is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period and the prompt reduction in THERMAL POWER in accordance with Required Action A.1. The maximum allowable Overpower T trip setpoints initially determined by Required Action A.3 may be affected by subsequent determinations of FQ C(Z) and would require Overpower T trip setpoint reductions within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months of the FQ C(Z) determination, if necessary to comply with the decreased maximum allowable Overpower T trip setpoints. Decreases in FQ C(Z) would allow increasing the maximum allowable Overpower T trip setpoints.

A.4 Verification that FQ C(Z) has been restored to within its limit by performing SR 3.2.1.1 and SR 3.2.1.2 prior to increasing THERMAL POWER above the limit imposed by Required Action A.1, assures that core conditions during operation at higher power levels and future operation are consistent with safety analyses assumptions.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-6 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 28 BASES ACTIONS (continued)

Condition A is modified by a Note that requires Required Action A.4 to be performed whenever the Condition is entered. This ensures that SR 3.2.1.1 and SR 3.2.1.2 will be performed prior to increasing THERMAL POWER above the limit of Required Action A.1, even when Condition A is exited prior to performing Required Action A.4.

Performance of SR 3.2.1.1 and SR 3.2.1.2 are necessary to assure FQ(Z) is properly evaluated prior to increasing THERMAL POWER.

B.1 If it is found that the maximum calculated value of FQ(Z) which can occur during normal maneuvers, FQ W(Z), exceeds its specified limits, there exists a potential for FQ C(Z) to become excessively high if a normal operational transient occurs. Reducing the AFD by 1% for each 1% by which FQ W(Z) exceeds its limit within the allowed Completion Time of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months restricts the axial flux distribution such that even if a transient occurred, core peaking factors would not be exceeded.

The implicit assumption is that if W(Z) values were recalculated (consistent with the reduced AFD limits), then FQ C(Z) times the recalculated W(Z) values would meet the FQ(Z) limit. Note that complying with this action (of reducing AFD limits) may also result in a power reduction. Hence the need for B.2, B.3, and B.4.

B.2 A reduction of the Power Range Neutron Flux-High trip setpoints by 1% for each 1% by which the maximum allowable power is reduced, is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period and the preceding prompt reduction in THERMAL POWER as a result of reducing AFD limits in accordance with Required Action B.1.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-7 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 29 BASES ACTIONS (continued)

B.3 Reduction in the Overpower T trip setpoints value of K4 by 1% for each 1% by which the maximum allowable power is reduced, is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period, and the preceding prompt reduction in THERMAL POWER as a result of reducing AFD limits in accordance with Required Action B.1.

B.4 Verification that FQ W(Z) has been restored to within its limit, by performing SR 3.2.1.1 and SR 3.2.1.2 prior to increasing THERMAL POWER above the maximum allowable power limit imposed by Required Action B.1 ensures that core conditions during operation at higher power levels and future operation are consistent with safety analyses assumptions.

Condition B is modified by a Note that requires Required Action B.4 to be performed whenever the Condition is entered. This ensures that SR 3.2.1.1 and SR 3.2.1.2 will be performed prior to increasing THERMAL POWER above the limit of Required Action B.1, even when Condition A is exited prior to performing Required Action B.4.

Performance of SR 3.2.1.1 and SR 3.2.1.2 are necessary to assure FQ(Z) is properly evaluated prior to increasing THERMAL POWER.

C.1 If Required Actions A.1 through A.4 or B.1 through B.4 are not met within their associated Completion Times, the plant must be placed in a MODE or condition in which the LCO requirements are not applicable. This is done by placing the plant in at least MODE 2 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

This allowed Completion Time is reasonable based on operating experience regarding the amount of time it takes to reach MODE 2 from full power operation in an orderly manner without challenging plant systems.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-8 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 30 BASES SURVEILLANCE REQUIREMENTS SR 3.2.1.1 and SR 3.2.1.2 are modified by twoa Notes., The first note which applies to the situation where the OPDMS is inoperablenot monitoring parameters at the beginning of cycle startup, i.e., the.

Note 1 applies during the first power ascension after a refueling. It states that performance of these SRs is not required if OPDMS was monitoring parameters upon exceeding 75% RTP.THERMAL POWER may be increased until an equilibrium power level has been achieved at which a power distribution map can be obtained. This allowance is modified, however, by one of the Frequency conditions that requires verification that FQC (Z) and FQW (Z) are within their specified limits after a power rise of more than 10% of RTP over the THERMAL POWER at which they were last verified to be within specified limits. Because FQ C

(Z) and FQ W(Z) could not have previously been measured in this reload core, there is a second the SR 3.2.1.1 and SR 3.2.1.2 Frequency is condition, applicable only for reload cores, andthat requires determination of these parameters before exceeding 75% RTP. This ensures that some determination of FQ C(Z) and FQ W(Z) are made at a lower power level at which adequate margin is available before going to 100%

RTP. Also, thisSR 3.2.1.1 and SR 3.2.1.2 Frequency condition, together with the SR 3.2.1.3 and SR 3.2.1.4 first Frequency condition requiring verification of FQ C(Z) and FQ W(Z) following a power increase of more than 10%, ensures that they are verified as soon as RTP (or any other level for extended operation) is achieved. In the absence of these Frequency conditions, it is possible to increase power to RTP and operate for 31 days without verification of FQ C(Z) and FQ W(Z). The SR 3.2.1.3 and SR 3.2.1.4 first Frequency condition is not intended to require verification of these parameters after every 10% increase in power level above the last verification. TheyIt only requires verification after an equilibrium power level is achieved for extended operation that is 10% higher than that power at which FQ(Z) was last measured.

The second Note SR 3.2.1.3 Note and SR 3.2.1.4 Note 1 applyies to the situation where the OPDMS is no longer monitoring parametersbecomes inoperable while the plant is in MODE 1. Without the continuous monitoring capability of the OPDMS, FQ limits must be monitored on a periodic basis. The first measurement must be made within 31 days of the most recent date where the OPDMS data has verified peak linear power densitykw/ft (Z) (and therefore also FQ) to be within its limit. This is consistent with the 31 day Surveillance Frequency.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-9 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 31 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.2.1.1 and SR 3.2.1.3 Verification that FQ C(Z) is within its specified limits involves increasing the measured values of FQ C(Z) to allow for manufacturing tolerance and measurement uncertainties in order to obtain FQ C(Z). Specifically, FQ M(Z) is the measured value of FQ(Z) obtained from incore flux map results and FQ C(Z) = FQ M(Z)

F Q MU(Z). FQ C(Z) is then compared to its specified limits.

The limit to which FQ C(Z) is compared varies inversely with power above 50% RTP.

Performing the Surveillance in MODE 1 prior to exceeding 75% RTP assures that the FQ C(Z) limit is met when RTP is achieved because Peaking Factors generally decrease as power level is increased.

If THERMAL POWER has been increased by 10% RTP since the last determination of FQ C(Z), another evaluation of this factor is required 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions at this higher power level (to assure that FQ C(Z) values are being reduced sufficiently with power increase to stay within the LCO limits).

The Frequency of 31 effective full power days (EFPDs) is adequate to monitor the change of power distribution with core burnup because such changes are slow and well controlled when the plant is operated in accordance with Technical Specifications.

SR 3.2.1.2 and SR 3.2.1.4 The nuclear design process includes calculations performed to determine that the core can be operated within the FQ(Z) limits. Because flux maps are taken in steady state conditions, the variations in power distribution resulting from normal operational maneuvers are not present in the flux map data. These variations are, however, conservatively calculated by considering a wide range of unit maneuvers in normal operation. The maximum peaking factor increase over steady state values, calculated as a function of core elevation, Z, is called W(Z). Multiplying the measured total peaking factor, FQ C(Z), by W(Z) gives the maximum FQ(Z) calculated to occur in normal operation, FQ W(Z).

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-10 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 32 BASES SURVEILLANCE REQUIREMENTS (continued)

The limit to which FQ W(Z) is compared varies inversely with power.

The W(Z) curve is provided in the COLR for discrete core elevations.

FQ W(Z) evaluations are not applicable for the following axial core regions, measured in percent of core height:

a.

Lower core region, from 0% to 15% inclusive; and

b.

Upper core region, from 85% to 100% inclusive.

The top and bottom 15% of the core are excluded from the evaluation because of the difficulty of making a precise measurement in these regions and because of the low probability that these regions would be more limiting than the safety analyses.

This Surveillance SR 3.2.1.4 has been modified by a Note 2, which may require that more frequent surveillances be performed. If FQ W(Z) is evaluated and found to be within its limit, an evaluation of the expression below is required to account for any increase to FQ M(Z) which could occur and cause the FQ(Z) limit to be exceeded before the next required FQ(Z) evaluation.

If the two most recent FQ(Z) evaluations show an increase in FQ C(Z), it is required to meet the FQ(Z) limit with the last FQ W(Z) increased by the greater of a factor of 1.02 or by an appropriate factor as specified in the COLR or to evaluate FQ(Z) more frequently, each 7 EFPDs. These alternative requirements will prevent FQ(Z) from exceeding its limit for any significant period of time without detection.

Performing the Surveillance in MODE 1 prior to exceeding 75% of RTP ensures that the FQ(Z) limit will be met when RTP is achieved, because peaking factors are generally decreased as power level is increased.

The Surveillance Frequency of 31 EFPDs is adequate to monitor the change of power distribution because such a change is sufficiently slow, when the plant is operated in accordance with Technical Specifications, to preclude the occurrence of adverse peaking factors between 31 EFPD Surveillances. The Surveillance may be done more frequently if required by the results of FQ(Z) evaluations.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-11 Amendment 0Rev. 0 Revision 19 Date report generated:

Thursday, June 25, 2015 Page 33 BASES SURVEILLANCE REQUIREMENTS (continued)

FQ(Z) is verified at power increases of at least 10% RTP above the THERMAL POWER of its last verification, 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions, to assure that FQ(Z) will be within its limit at higher power levels.

REFERENCES

1.

10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors, 1974.

2.

Regulatory Guide 1.77, Rev. 0, Assumptions Used for Evaluating a Control Rod Ejection Accident for Pressurized Water Reactors, May 1974.

3.

10 CFR 50, Appendix A, GDC 26.

4.

WCAP-7308-L-P-A, Evaluation of Nuclear Hot Channel Factor Uncertainties, June 1988 (Westinghouse Proprietary) and WCAP-7308-L-A (Non-Proprietary).

5.

WCAP-10216-P-A, Revision 1A, Relaxation of Constant Axial Offset Control FQ Surveillance Technical Specification, February 1994 (Westinghouse Proprietary) and WCAP-10217-A (Non-Proprietary).

GTST AP1000-B21-3.2.1, Rev. 1 Date report generated:

Thursday, June 25, 2015 Page 34 XII. Applicable STS Subsection After Incorporation of this GTSTs Modifications The entire subsection of the Specifications and the Bases associated with this GTST, following incorporation of the modifications, is presented next.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-1 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 35 3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology)

LCO 3.2.1 FQ(Z), as approximated by FQ C(Z) and FQ W(Z), shall be within the limits specified in the COLR.

APPLICABILITY:

MODE 1 with On-line Power Distribution Monitoring System (OPDMS) not monitoring parameters.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. ------------NOTE------------

Required Action A.4 shall be completed whenever this Condition is entered.

FQ C(Z) not within limit.

A.1 Reduce THERMAL POWER 1% RTP for each 1% FQ C(Z) exceeds limit.

AND 15 minutes after each FQ C(Z) determination A.2 Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1%

FQ C(Z) exceeds limit.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months after each FQ C(Z) determination A.3 Reduce Overpower T trip setpoints 1% for each 1%

FQ C(Z) exceeds limit.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months after each FQ C(Z) determination A.4 Perform SR 3.2.1.1 and SR 3.2.1.2.

Prior to increasing THERMAL POWER above the limit of Required Action A.1

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-2 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 36 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. ------------NOTE------------

Required Action B.4 shall be completed whenever this Condition is entered.

FQ W(Z) not within limits.

B.1 Reduce AFD limits 1% for each 1% FQ W(Z) exceeds limit.

AND 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months B.2 Reduce Power Range Neutron Flux - High trip setpoints 1% for each 1%

that the maximum allowable power of the AFD limits is reduced.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.3 Reduce Overpower T trip setpoints 1% for each 1%

that the maximum allowable power of the AFD limits is reduced.

AND 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.4 Perform SR 3.2.1.1 and SR 3.2.1.2.

Prior to increasing THERMAL POWER above the maximum allowable power of the AFD limits C. Required Action and associated Completion Time not met.

C.1 Be in MODE 2.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-3 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 37 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.2.1.1

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

Not required to be performed if OPDMS was monitoring parameters upon exceeding 75% RTP.

Verify FQ C(Z) within limit.

Once after each refueling prior to THERMAL POWER exceeding 75% RTP SR 3.2.1.2

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

Not required to be performed if OPDMS was monitoring parameters upon exceeding 75% RTP.

Verify FQ W(Z) within limits.

Once after each refueling prior to THERMAL POWER exceeding 75% RTP SR 3.2.1.3

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

Not required to be performed until 31 days after the last verification of OPDMS parameters.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-4 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 38 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.2.1.3 (continued)

Verify FQ C(Z) within limit.

Once within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which FQ C(Z) was last verified AND 31 effective full power days (EFPD) thereafter SR 3.2.1.4

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

1. Not required to be performed until 31 days after the last verification of OPDMS parameters.

2. If FQ W(Z) measurements indicate maximum over zFQ C(Z) has increased since the previous evaluation of FQ C(Z):

a. Increase FQ W(Z) by the greater of a factor of 1.02 or by an appropriate factor specified in the COLR and reverify FQ W(Z) is within limits; or

b. Repeat SR 3.2.1.4 once per 7 EFPD until two successive flux maps indicate maximum over zFQ C(Z) has not increased.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology) 3.2.1 AP1000 STS 3.2.1-5 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 39 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.2.1.4 (continued)

Verify FQ W(Z) within limits.

Once within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions after exceeding, by 10% RTP, the THERMAL POWER at which FQ W(Z) was last verified AND 31 EFPD thereafter

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-1 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 40 B 3.2 POWER DISTRIBUTION LIMITS B 3.2.1 Heat Flux Hot Channel Factor (FQ(Z)) (FQ Methodology)

BASES BACKGROUND The purpose of the limits on the values of FQ(Z) is to limit the local (i.e.,

pellet) peak power density. The value of FQ(Z) varies along the axial height (Z) of the core.

FQ(Z) is defined as the maximum local fuel rod linear power density divided by the average fuel rod linear power density, assuming nominal fuel pellet and fuel rod dimensions. Therefore, FQ(Z) is a measure of the peak fuel pellet power within the reactor core.

During power operation with the On-line Power Distribution Monitoring System (OPDMS) not monitoring parameters, the global power distribution is limited by LCO 3.2.3, AXIAL FLUX DIFFERENCE (AFD),

and LCO 3.2.4, QUADRANT POWER TILT RATIO (QPTR), which are directly and continuously measured process variables. These LCOs along with LCO 3.1.6, Control Bank Insertion Limits, maintain the core limits on power distributions on a continuous basis.

FQ(Z) varies with fuel loading patterns, control bank insertion, fuel burnup, and changes in axial power distribution.

With the OPDMS monitoring parameters, peak linear power density (which is proportional to FQ(Z)) is measured continuously. With the OPDMS not monitoring parameters, FQ(Z) is measured periodically using the incore detector system. These measurements are generally taken with the core at or near steady state conditions.

With the measured three dimensional power distributions, it is possible to derive a measured value for FQ(Z) with the OPDMS not monitoring parameters. However, because this value represents a steady state condition, it does not include the variations in the value of FQ(Z) which are present during a nonequilibrium situation such as load following.

To account for these possible variations, the steady state value of FQ(Z) is adjusted by an elevation dependent factor to account for the calculated worst case transient conditions.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-2 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 41 BASES BACKGROUND (continued)

Core monitoring and control under non-equilibrium conditions and the OPDMS not monitoring parameters are accomplished by operating the core within the limits of the appropriate LCOs, including the limits on AFD, QPTR, and control rod insertion.

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

a.

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

b.

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

Limits on FQ(Z) ensure that the value of the initial total peaking factor assumed in the accident analyses remains valid. Other criteria must also be met (e.g., maximum cladding oxidation, maximum hydrogen generation, coolable geometry, and long term cooling). However, the peak cladding temperature is typically most limiting.

FQ(Z) limits assumed in the LOCA analysis are typically limiting (i.e.,

lower than) relative to the FQ(Z) assumed in safety analyses for other postulated accidents. Therefore, this LCO provides conservative limits for other postulated accidents.

FQ(Z) satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-3 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 42 BASES LCO The Heat Flux Hot Channel Factor, FQ(Z), shall be limited by the following relationships:

FQ(Z) CFQ / P for P > 0.5 FQ(Z) CFQ / 0.5 for P 0.5 where: CFQ is the FQ(Z) limit at RTP provided in the COLR, P = THERMAL POWER / RTP The actual values of CFQ are given in the COLR; however, CFQ is normally a number on the order of 2.60. The normalized FQ(Z) as a function of core height is 1.0.

For RAOC operation, FQ(Z) is approximated by FQ C(Z) and FQ W(Z). Thus, both FQ C(Z) and FQ W(Z) must meet the preceding limits on FQ(Z).

An FQ C(Z) evaluation requires obtaining an incore flux map in MODE 1.

From the incore flux map results the measured value of FQ(Z), called FQ M(Z) is obtained. Then, FQ C(Z) = FQ M(Z)

F Q MU(Z) where F Q MU(Z) is a factor that accounts for fuel manufacturing tolerances and flux map measurement uncertainty. F Q MU(Z) is provided in the COLR.

FQ C(Z) is an excellent approximation for FQ(Z) when the reactor is at the steady state power at which the incore flux map was taken.

The expression for FQ W(Z) is:

FQ W(Z) = FQ C(Z)

W(Z) where W(Z) is a cycle-dependent function that accounts for power distribution transients encountered during normal operation. W(Z) is included in the COLR.

The FQ(Z) limits define limiting values for core power peaking that precludes peak cladding temperatures above 2200°F during either a large or small break LOCA.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-4 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 43 BASES LCO (continued)

This LCO requires operation within the bounds assumed in the safety analyses. Calculations are performed in the core design process to confirm that the core can be controlled in such a manner during operation that it can stay within the LOCA FQ(Z) limits. If FQ(Z) cannot be maintained within the LCO limits, reduction of the core power is required and if FQ W(Z) cannot be maintained within LCO limits, reduction of the AFD limits will also result in a reduction of the core power.

Violating the LCO limits for FQ(Z) may result in an unanalyzed condition while FQ(Z) is outside its specified limits.

APPLICABILITY When the OPDMS is not monitoring parameters and core power distribution parameters cannot be continuously monitored, it is necessary to determine FQ(Z) on a periodic basis. Furthermore, the FQ(Z) limits must be maintained in MODE 1 to prevent core power distributions from exceeding the limits assumed in the safety analyses. Applicability 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 a limit on the distribution of core power.

ACTIONS A.1 Reducing THERMAL POWER by 1% of RTP for each 1% by which FQ C(Z) exceeds its limit, maintains an acceptable absolute power density.

FQ C(Z) is FQ M(Z) multiplied by a factor accounting for fuel manufacturing tolerances and flux map measurement uncertainties. FQ M(Z) is the measured value of FQ(Z). The Completion Time of 15 minutes provides an acceptable time to reduce power in an orderly manner without allowing the plant to remain in an unacceptable condition for an extended period of time. The maximum allowable power level initially determined by Required Action A.1 may be affected by subsequent determinations of FQ C(Z) and would require power reductions within 15 minutes of the FQ C(Z) determination, if necessary to comply with the decreased maximum allowable power level. Decreases in FQ C(Z) would allow increasing the maximum allowable power level and increasing power up to this revised limit.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-5 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 44 BASES ACTIONS (continued)

A.2 A reduction of the Power Range Neutron Flux - High Trip setpoints by 1% for each 1% by which FQ C(Z) exceeds its limit is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period and the prompt reduction in THERMAL POWER in accordance with Required Action A.1. The maximum allowable Power Range Neutron Flux - High trip setpoints initially determined by Required Action A.2 may be affected by subsequent determinations of FQ C(Z) and would require Power Range Neutron Flux - High trip setpoint reductions within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months of the FQ C(Z) determination, if necessary to comply with the decreased maximum allowable Power Range Neutron Flux - High trip setpoints. Decreases in FQ C(Z) would allow increasing the maximum allowable Power Range Neutron Flux - High trip setpoints.

A.3 Reduction in the Overpower T Trip setpoints (value of K4) by 1% for each 1% by which FQ C(Z) exceeds its limit is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period and the prompt reduction in THERMAL POWER in accordance with Required Action A.1. The maximum allowable Overpower T trip setpoints initially determined by Required Action A.3 may be affected by subsequent determinations of FQ C(Z) and would require Overpower T trip setpoint reductions within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months of the FQ C(Z) determination, if necessary to comply with the decreased maximum allowable Overpower T trip setpoints. Decreases in FQ C(Z) would allow increasing the maximum allowable Overpower T trip setpoints.

A.4 Verification that FQ C(Z) has been restored to within its limit by performing SR 3.2.1.1 and SR 3.2.1.2 prior to increasing THERMAL POWER above the limit imposed by Required Action A.1, assures that core conditions during operation at higher power levels and future operation are consistent with safety analyses assumptions.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-6 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 45 BASES ACTIONS (continued)

Condition A is modified by a Note that requires Required Action A.4 to be performed whenever the Condition is entered. This ensures that SR 3.2.1.1 and SR 3.2.1.2 will be performed prior to increasing THERMAL POWER above the limit of Required Action A.1, even when Condition A is exited prior to performing Required Action A.4.

Performance of SR 3.2.1.1 and SR 3.2.1.2 are necessary to assure FQ(Z) is properly evaluated prior to increasing THERMAL POWER.

B.1 If it is found that the maximum calculated value of FQ(Z) which can occur during normal maneuvers, FQ W(Z), exceeds its specified limits, there exists a potential for FQ C(Z) to become excessively high if a normal operational transient occurs. Reducing the AFD by 1% for each 1% by which FQ W(Z) exceeds its limit within the allowed Completion Time of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months restricts the axial flux distribution such that even if a transient occurred, core peaking factors would not be exceeded.

The implicit assumption is that if W(Z) values were recalculated (consistent with the reduced AFD limits), then FQ C(Z) times the recalculated W(Z) values would meet the FQ(Z) limit. Note that complying with this action (of reducing AFD limits) may also result in a power reduction. Hence the need for B.2, B.3, and B.4.

B.2 A reduction of the Power Range Neutron Flux-High trip setpoints by 1% for each 1% by which the maximum allowable power is reduced, is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period and the preceding prompt reduction in THERMAL POWER as a result of reducing AFD limits in accordance with Required Action B.1.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-7 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 46 BASES ACTIONS (continued)

B.3 Reduction in the Overpower T trip setpoints value of K4 by 1% for each 1% by which the maximum allowable power is reduced, is a conservative action for protection against the consequences of severe transients with unanalyzed power distributions. The Completion Time of 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is sufficient considering the small likelihood of a severe transient in this time period, and the preceding prompt reduction in THERMAL POWER as a result of reducing AFD limits in accordance with Required Action B.1.

B.4 Verification that FQ W(Z) has been restored to within its limit, by performing SR 3.2.1.1 and SR 3.2.1.2 prior to increasing THERMAL POWER above the maximum allowable power limit imposed by Required Action B.1 ensures that core conditions during operation at higher power levels and future operation are consistent with safety analyses assumptions.

Condition B is modified by a Note that requires Required Action B.4 to be performed whenever the Condition is entered. This ensures that SR 3.2.1.1 and SR 3.2.1.2 will be performed prior to increasing THERMAL POWER above the limit of Required Action B.1, even when Condition A is exited prior to performing Required Action B.4.

Performance of SR 3.2.1.1 and SR 3.2.1.2 are necessary to assure FQ(Z) is properly evaluated prior to increasing THERMAL POWER.

C.1 If Required Actions A.1 through A.4 or B.1 through B.4 are not met within their associated Completion Times, the plant must be placed in a MODE or condition in which the LCO requirements are not applicable. This is done by placing the plant in at least MODE 2 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

This allowed Completion Time is reasonable based on operating experience regarding the amount of time it takes to reach MODE 2 from full power operation in an orderly manner without challenging plant systems.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-8 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 47 BASES SURVEILLANCE REQUIREMENTS SR 3.2.1.1 and SR 3.2.1.2 are modified by a Note, which applies to the situation where the OPDMS is not monitoring parameters at the beginning of cycle startup, i.e., the Note applies during the first power ascension after a refueling. It states that performance of these SRs is not required if OPDMS was monitoring parameters upon exceeding 75%

RTP. Because FQ C(Z) and FQ W(Z) could not have previously been measured in this reload core, the SR 3.2.1.1 and SR 3.2.1.2 Frequency is applicable only for reload cores, and requires determination of these parameters before exceeding 75% RTP. This ensures that some determination of FQ C(Z) and FQ W(Z) are made at a lower power level at which adequate margin is available before going to 100% RTP. Also, SR 3.2.1.1 and SR 3.2.1.2 Frequency together with the SR 3.2.1.3 and SR 3.2.1.4 first Frequency requiring verification of FQ C(Z) and FQ W(Z) following a power increase of more than 10%, ensures that they are verified as soon as RTP (or any other level for extended operation) is achieved. In the absence of these Frequency conditions, it is possible to increase power to RTP and operate for 31 days without verification of FQ C(Z) and FQ W(Z). The SR 3.2.1.3 and SR 3.2.1.4 first Frequency is not intended to require verification of these parameters after every 10%

increase in power level above the last verification. They only require verification after an equilibrium power level is achieved for extended operation that is 10% higher than that power at which FQ(Z) was last measured.

The SR 3.2.1.3 Note and SR 3.2.1.4 Note 1 apply to the situation where the OPDMS is no longer monitoring parameters while the plant is in MODE 1. Without the continuous monitoring capability of the OPDMS, FQ limits must be monitored on a periodic basis. The first measurement must be made within 31 days of the most recent date where the OPDMS data has verified peak linear power density (and therefore also FQ) to be within its limit. This is consistent with the 31 day Surveillance Frequency.

SR 3.2.1.1 and SR 3.2.1.3 Verification that FQ C(Z) is within its specified limits involves increasing the measured values of FQ C(Z) to allow for manufacturing tolerance and measurement uncertainties in order to obtain FQ C(Z). Specifically, FQ M(Z) is the measured value of FQ(Z) obtained from incore flux map results and FQ C(Z) = FQ M(Z)

F Q MU(Z). FQ C(Z) is then compared to its specified limits.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-9 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 48 BASES SURVEILLANCE REQUIREMENTS (continued)

The limit to which FQ C(Z) is compared varies inversely with power above 50% RTP.

Performing the Surveillance in MODE 1 prior to exceeding 75% RTP assures that the FQ C(Z) limit is met when RTP is achieved because Peaking Factors generally decrease as power level is increased.

If THERMAL POWER has been increased by 10% RTP since the last determination of FQ C(Z), another evaluation of this factor is required 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions at this higher power level (to assure that FQ C(Z) values are being reduced sufficiently with power increase to stay within the LCO limits).

The Frequency of 31 effective full power days (EFPDs) is adequate to monitor the change of power distribution with core burnup because such changes are slow and well controlled when the plant is operated in accordance with Technical Specifications.

SR 3.2.1.2 and SR 3.2.1.4 The nuclear design process includes calculations performed to determine that the core can be operated within the FQ(Z) limits. Because flux maps are taken in steady state conditions, the variations in power distribution resulting from normal operational maneuvers are not present in the flux map data. These variations are, however, conservatively calculated by considering a wide range of unit maneuvers in normal operation. The maximum peaking factor increase over steady state values, calculated as a function of core elevation, Z, is called W(Z). Multiplying the measured total peaking factor, FQ C(Z), by W(Z) gives the maximum FQ(Z) calculated to occur in normal operation, FQ W(Z).

The limit to which FQ W(Z) is compared varies inversely with power.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-10 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 49 BASES SURVEILLANCE REQUIREMENTS (continued)

The W(Z) curve is provided in the COLR for discrete core elevations.

FQ W(Z) evaluations are not applicable for the following axial core regions, measured in percent of core height:

a.

Lower core region, from 0% to 15% inclusive; and

b.

Upper core region, from 85% to 100% inclusive.

The top and bottom 15% of the core are excluded from the evaluation because of the difficulty of making a precise measurement in these regions and because of the low probability that these regions would be more limiting than the safety analyses.

SR 3.2.1.4 has been modified by Note 2, which may require that more frequent surveillances be performed. If FQ W(Z) is evaluated and found to be within its limit, an evaluation of the expression below is required to account for any increase to FQ M(Z) which could occur and cause the FQ(Z) limit to be exceeded before the next required FQ(Z) evaluation.

If the two most recent FQ(Z) evaluations show an increase in FQ C(Z), it is required to meet the FQ(Z) limit with the last FQ W(Z) increased by the greater of a factor of 1.02 or by an appropriate factor as specified in the COLR or to evaluate FQ(Z) more frequently, each 7 EFPDs. These alternative requirements will prevent FQ(Z) from exceeding its limit for any significant period of time without detection.

Performing the Surveillance in MODE 1 prior to exceeding 75% of RTP ensures that the FQ(Z) limit will be met when RTP is achieved, because peaking factors are generally decreased as power level is increased.

The Surveillance Frequency of 31 EFPDs is adequate to monitor the change of power distribution because such a change is sufficiently slow, when the plant is operated in accordance with Technical Specifications, to preclude the occurrence of adverse peaking factors between 31 EFPD Surveillances. The Surveillance may be done more frequently if required by the results of FQ(Z) evaluations.

GTST AP1000-B21-3.2.1, Rev. 1 FQ(Z) (FQ Methodology)

B 3.2.1 AP1000 STS B 3.2.1-11 Rev. 0 Date report generated:

Thursday, June 25, 2015 Page 50 BASES SURVEILLANCE REQUIREMENTS (continued)

FQ(Z) is verified at power increases of at least 10% RTP above the THERMAL POWER of its last verification, 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after achieving equilibrium conditions, to assure that FQ(Z) will be within its limit at higher power levels.

REFERENCES

1.

10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors, 1974.

2.

Regulatory Guide 1.77, Rev. 0, Assumptions Used for Evaluating a Control Rod Ejection Accident for Pressurized Water Reactors, May 1974.

3.

10 CFR 50, Appendix A, GDC 26.

4.

WCAP-7308-L-P-A, Evaluation of Nuclear Hot Channel Factor Uncertainties, June 1988 (Westinghouse Proprietary) and WCAP-7308-L-A (Non-Proprietary).

5.

WCAP-10216-P-A, Revision 1A, Relaxation of Constant Axial Offset Control FQ Surveillance Technical Specification, February 1994 (Westinghouse Proprietary) and WCAP-10217-A (Non-Proprietary).

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