ML13268A449

Response to Request for Additional Information Regarding Core Operating Limits Report for Cycle 21

ML13268A449
Person / Time
Site:	Catawba
Issue date:	09/26/2013
From:	Henderson K Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC MF1777
Download: ML13268A449 (7)

Text

Kelvin Henderson DUKE ENERGY° Vice President Catawba Nuclear Station 803-701-4251 Duke Energy CNO1VP I 4800 Concord Rd.

York, SC 29745 September 26, 2013 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555

Subject:

Duke Energy Carolinas, LLC (Duke Energy)

Catawba Nuclear Station, Unit 1 Docket Number 50-413 Response to Request for Additional Information Regarding Core Operating Limits Report for Cycle 21 (TAC NO. MF1777)

Reference:

Letter from NRC to Duke Energy dated August 20, 2013 The reference letter requested additional information concerning the Catawba Unit 1 Cycle 21 Core Operating Limits Report (COLR). The purpose of this letter is to respond to this request. The attachment to this letter provides Catawba's responses to the questions contained in the reference letter.

There are no regulatory commitments contained in this letter or its attachment.

Inquiries on this matter should be directed to L.J. Rudy at (803) 701-3084.

Very truly yours, Kelvin Henderson LJR/s Attachment w de www duke-energy corn

U.S. Nuclear Regulatory Commission Page 2 September 26, 2013 xc (with attachment):

V.M. McCree Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 G.A. Hutto, III Senior Resident Inspector (Catawba)

U.S. Nuclear Regulatory Commission Catawba Nuclear Station J.C. Paige (addressee only)

NRC Project Manager (Catawba)

U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 8 G9A 11555 Rockville Pike Rockville, MD 20852-2738

ATTACHMENT RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION CATAWBA UNIT 1 CYCLE 21 CORE OPERATING LIMITS REPORT (COLR) 1

1. The analytical methods used to determine core operating limits for parameters identified in TS come from methodologies approved by the NRC. The approved methodologies used by Catawba are listed in Section 1.1 of the COLR. Please list which of these approved methodologies is used to determine each operating limit in Section 2.0.

Duke Energy Response:

An example of Duke Energy Core Operating Limits Report (COLR) Section 1 that lists the NRC approved methods in Section 1.1 to analytical methods used to develop and/or determine COLR parameter limits identified in Technical Specifications in Section 2 is provided on the next page.

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1.0 Core Operating Limits Report - Example of CIC21 COLR Section 1.0 for NRC Request for Additional Information This Core Operating Limits Report (COLR) has been prepared in accordance with the requirements of Technical Specification 5.6.5. The Technical Specifications that reference this report are listed below along with the NRC approved analytical methods used to develop and/or determine COLR parameters identified in Technical Specifications.

TS COLR NRC Approved Section Technical Specifications COLR Parameter Section Methodology (Section 1.1 Number) 2.1.1 Reactor Core Safety Limits RCS Temperature and 2.1 6, 7, 8, 9, 10, 12, 15, 16

. .... Pressure Safety

. . . Limits

.. iii iiii l

..... t !

.......y

.ttM

. r i .. ... ...........

M .. ...........

........ 6 , 7 ........... 4

...... _1

.2!

3.1.1 Shutdown Margin SDM 2.2 6, 7, 8, 12, 14, 15, 16 ....

3.1.3

.. Moderator

........... .... Temperature .... ... Coefficient . . ...... MTC........... ....... . ......... 2.32 .. ... ...

.................. .i.g..6,.....

}, 7,......

8 8,.. 12, 414, 516..............

....14........

3.1.4 .. .......

. R Rodo.r Group u A Alignment.. e................

.gn .. !Limits m t .... ..... ......... SD...........

SDM M.. ...........

...... . ..2.2......................

...... 2.2 ................

6, ......

7,..8,..4 12,6....... i 8 15, 14, ..................................

9 16 3.1.5 Shutdown Bank Insertion Limit SDM 2.2 2,4, 6, 7, 8, 9, Rod Insertion Limits 2.4 10, 12, 14, 15, 16 3.1.6 Control Bank Insertion Limit SDM 2.2 2, 4, 6, 7, 8, 9,

.3!8........ .P......c s.....

ep

..... s..................

....... Rod SD ... M....Insertion

.. ....... Limits

... 2.5 2..

.... ... ...... 10, 6 , .........

7..!. 12, 14,1.. ....

.. 15,

. 516!6............

3.1.8 Physics Tests Exceptions SDM 2.2 6, 7, 8, 12, 14, 15, 16 3.2.1 Heat Flux Hot Channel Factor Fo 2.6 2, 4, 6, 7, 8, 9, 10, AFD 2.8 12, 15, 16 OTAT 2.9 Penalty Factors 2.6 3.2.2 Nuclear Enthalpy Rise Hot Channel FAH 2.7 2, 4, 6, 7, 8, 9, 10, 12, Factor Penalty Factors 2.6 15, 16 3.2.3 '3 i2. . x. .a Flux Axial l xD f e e c ..... .................

Difference .................. AFD .F.......... ...... .............

2.88. 2.1 2, 4,., 6 6, 77, 8,..................

i15, 5 16 3.3.1 Reactor Trip System Instrumentation OTAT 2.9 6, 7, 8, 9, 10, 12, 15, 16 OPAT 2.9 3.3.9 Boron Dilution Mitigation System Reactor Makeup Water 2.10 6, 7,8, 12, 14, 16 SFlow Rate 3.4.1 RCS Pressure, Temperature and Flow RCS Pressure, 2.11 6, 7, 8, 9, 10, 12 n ts for limits o D DNB3 B_!.. . . .. ... ... ........ Temperature ....... aur~ and F

....................... Flowlo . .. . .......................... .n. .

............ 3.. AcmlaosMax Accum.... u .a ..rs.................

..... and

...... .. ..... Min Boron Conc.

.................. 2.12

................................. i ....... 6, 7, 8,-12,1-4,

................ 16 3.5.4 Refueling Water Storage Tank Max and Min Boron Cone. 2.13 6, 7, 8, 12,.14, 16 3.7.15 Spent Fuel Pool Boron Concentration Min Boron Concentration 2.14 6, 7, 8, 12, 14, 16 3.9.1 Refueling Operations - Boron Min Boron Concentration 2.15 6, 7, 8, 12, 14, 16 SConcentration

• 5.6.5 Core Operating Limits Report (COLR) Analytical Methods 1.1 None The Selected License Commitments that reference this report are listed below:

SLC COLR NRC Approved Section Selected Licensing Commitment COLR Parameter Section Methodology (Section 1.1 Number) 16.7-9 Standby Shutdown System .. .......... .. *W Standby Makeup Pump ater* Su*pplY...... 2.16 6, 7, 8, 12, 14, 16 16.9-11 Boration Systems - Borated Water Borated Water Volume and 2.17 6, 7, 8, 12, 14, 16 Source - Shutdown iConc. for BAT/RWST 16.9-12 Boration Systems - Borated Water Borated Water Volume and 2.18 6, 7, 8, 12, 14, 16 Source - Operating Cone. for BAT/RWST 3

2. In the COLR for Catawba Nuclear Station, Unit 1, Cycle 20 dated April 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML11168A068), an exception was given under Shutdown Bank Insertion Limits in Section 2.4. The exception states:

Shutdown banks may be inserted to 219 steps withdrawn individually for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> provided the plant was operated in steady state conditions near 100% FP

[full power] prior to and during this exception.

Describe why this exception was eliminated for the Cycle 21 COLR.

Duke Energy Response:

A combined response is provided below for Questions 2 and 3.

3. In the COLR for Catawba Nuclear Station, Unit 1, Cycle 20, an exception was given under Control Bank Insertion Limits in Section 2.5. The exception states:

Control banks A, B, or C may be inserted to 219 steps withdrawn individually for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> provided the plant was operated in steady state conditions near 100% FP prior to and during this exception.

Describe why this exception was eliminated for the Cycle 21 COLR.

Duke Energy Response:

In 2008, Catawba Operations requested that Nuclear Design perform an evaluation of the plant conditions to support changing the minimum control rod insertion limit position during Technical Specification (TS) Surveillance Requirement (SR) 3.1.4.2 (rod cluster control assemblies (RCCA) movement test) to assure that Chapter 15 accident analysis acceptance criteria remain satisfied should a card fault occur during completion of the RCCA movement test. An analysis was performed to assess reactivity and peaking impacts on Updated Final Safety Analysis Report (UFSAR) accident analyses for inserting shutdown banks and control banks to 219 steps withdrawn. This analysis was performed using NRC approved methods of TS 5.6.5.b. The results indicated that the reference safety analyses remained bounding for control and shutdown banks inserted to 219 steps withdrawn during performance of the RCCA movement test. This conclusion remained valid as long as the following conditions were maintained:

1) Any shutdown bank or control bank A, B, or C may be inserted to 219 steps withdrawn individually for a duration of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> anytime during the cycle provided the plant was operated in steady state conditions near 100% FP prior to and during this exception.

2) Any time any shutdown bank or control bank A, B, or C is inserted below 222 steps withdrawn, control bank D insertion is limited to greater than or equal to 200 steps withdrawn.

Analysis assumption 1) was incorporated into the Catawba I Cycle 18, 19, and 20 COLR Section 2.4 and 2.5 and analysis assumption 2) was added to Figure 3.

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In 2008, the RCCA movement test procedure was revised to address continued problems encountered during the performance of the test procedure.

In 2011, upon further review of COLR Sections 2.4.2 and 2.5.2 and the previous revisions of the RCCA movement test procedure in 2008, it was concluded that the above provisions within the COLR were no longer necessary. The provisions and the decision to remove them were evaluated in the station corrective action program. Therefore, the provisions of COLR Sections 2.4.2 and 2.5.2 were removed from the Cycle 21 COLR.

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