ML15005A028

Palo Verde, Units 1, 2, & 3, Response to Request for Additional Information Regarding Application for Technical Specification Change Regarding Moderator Temperature Coefficient Surveillance for Startup Test Activity Reduction Program

ML15005A028
Person / Time
Site:	Palo Verde
Issue date:	12/19/2014
From:	Mims D C Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06973-DCM/TNW
Download: ML15005A028 (5)

Text

I 10 CFR 50.90 DWIGHT C. MIMS Senior Vice President, Nuclear Regulatory

& Oversight Palo Verde Nuclear Generating Station P.O. Box 52034 Phoenix, AZ 85072 Mail Station 7605 102-06973-DCM/TNW Tel 623 393 5403 December 19, 2014 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Response to Request for Additional Information Regarding Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance for Startup Test Activity Reduction (STAR) Program Using the Consolidated Line Item Improvement Process (CLIIP)By letter number 102-06784, dated November 20, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13329A037), as supplemented by letter number 102-06819, dated January 16, 2014 (ADAMS Accession No. ML14027A701), Arizona Public Service Company (APS) requested an amendment to the Palo Verde Nuclear Generating Station (PVNGS) technical specifications relating to the moderator temperature coefficient surveillance requirements for Startup Test Activity Reduction Program.The U.S. Nuclear Regulatory Commission (NRC) staff provided a request for additional information (RAI) by e-mail dated December 1, 2014, to complete its review of the license amendment request. A draft RAI was originally transmitted on November 13, 2014, and a clarification call relating to the draft RAI was held on November 24, 2014, with participants from NRC and APS. The NRC staff requested the APS response to the final RAI within 30 days of December 1, 2014.The enclosure to this letter provides the APS response to the NRC RAI. The RAI response remains consistent with the conclusion of the no significant hazards consideration determination

[10 CFR 50.91(a), Notice for public comment] provided in the original LAR.By copy of this letter, this LAR update is being forwarded to the Arizona Radiation Regulatory Agency (ARRA) pursuant to 10 CFR 50.91(b)(1), State consultation.

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance A o Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• Wolf Creek KI 102-06973-DCM/TNW ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Response to Request for Additional Information Regarding Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC)Surveillance for Startup Test Activity Reduction (STAR) Program Using the Consolidated Line Item Improvement Process (CLIIP)Page 2 No new commitments are being made to the NRC by this letter. Should you need further information regarding this submittal, please contact Thomas N. Weber, Licensing Department Leader, at (623) 393-5764.I declare under penalty of perjury that the foregoing is true and correct.Executed on Sincerely, DCM/TNW (Date)

Enclosure:

Response to Request for Additional Information Regarding Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance for Startup Test Activity Reduction (STAR) Program Using the Consolidated Line Item Improvement Process (CLIIP)cc: M. L. Dapas B. K. Singal M. M. Watford C. A. Peabody A. V. Godwin T. Morales NRC Region IV Regional Administrator NRC NRR Project Manager for PVNGS NRC NRR Project Manager NRC Senior Resident Inspector for PVNGS Arizona Radiation Regulatory Agency (ARRA)Arizona Radiation Regulatory Agency (ARRA)

Enclosure Response to Request for Additional Information Regarding Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance for Startup Test Activity Reduction (STAR) Program Using the Consolidated Line Item Improvement Process (CLIIP)

Response to Request for Additional Information Regarding Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance for Startup Test Activity Reduction (STAR)Program Using the Consolidated Line Item Improvement Process (CLIIP)Introduction By letter number 102-06784, dated November 20, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13329A037), as supplemented by letter number 102-06819, dated January 16, 2014 (ADAMS Accession No. ML14027A701), Arizona Public Service Company (APS) requested an amendment to the Palo Verde Nuclear Generating Station (PVNGS) technical specifications relating to the moderator temperature coefficient surveillance requirements for Startup Test Activity Reduction Program.The U.S. Nuclear Regulatory Commission (NRC) staff provided a request for additional information (RAI) by e-mail dated December 1, 2014, to complete its review of the license amendment request. A draft RAI was originally transmitted on November 13, 2014, and a clarification call relating to the draft RAI was held on November 24, 2014, with participants from NRC and APS. The NRC staff requested the APS response to the final RAI within 30 days of December 1, 2014.The NRC request is stated first followed by the APS response.NRC Request 1(a)1. Arizona Public Service (APS) has proposed a modification to the PVNGS Technical Specifications (TS) that would allow the plant to perform a calculation in lieu of a measurement to complete Surveillance Requirement (SR) 3.1.4.2, which supports the Limiting Condition for Operation (LCO) for most negative Moderator Temperature Coefficient (MTC) established in LCO 3.1.4.a. How would APS ensure that PVNGS remains within LCO 3.1.4 if the plant deviates from normal operation, up to the TS limits, after performance of the two-thirds cycle surveillance required by SR 3.1.4.2?APS Response APS performs a reload analysis (reload core safety evaluation) each cycle that includes a conservative calculation of the most negative MTC possible during the planned operating cycle. The analysis includes the biases, uncertainties and operating allowances required to ensure margin is maintained to the limits of LCO 3.1.4. The as-built core MTC will remain within the limits of LCO 3.1.4 provided the plant operates within the bounds established by the TS, the Core Operating Limits Report (COLR), and the cycle length evaluated in the reload analysis.

If plans were made to operate in a condition beyond that which was evaluated in the reload analysis, then an additional evaluation would be performed to validate that the limits of LCO 3.1.4 would not be challenged by the planned change.For example, the cycle specific reload analysis evaluates MTC beyond the planned cycle duration for operating margin. If plans were made to extend the expected life of the core beyond the burnup limit established in the reload analysis, an evaluation would be performed to validate that MTC remained within the bounds of LCO 3.1.4.1

-Response to Request for Additional Information Regarding Application for Technical Specification Change Regarding Moderator Temperature Coefficient (MTC) Surveillance for Startup Test Activity Reduction (STAR)Program Using the Consolidated Line Item Improvement Process (CLIIP)In addition,Section VIII, Deviation from Normal Operation, of topical report, CE NPSD-91 l-A, Analysis of Moderator Temperature Coefficients in Support of a Change in the Technical Specification End of Cycle Negative MTC Limit, dated September 15, 2000 (ADAMS Accession No. ML003752592), which is referenced in APS letter number 102-06784, dated November 20, 2013, uses PVNGS as an example for evaluations on the effects of off-normal plant operation on MTC. The topical report concludes that off normal plant operation has only minor effects on MTC.NRC Request 1(b)b. If the answer to the previous question involves comparison of predicted values to the LCO limit, what criteria would APS use to determine whether or not a reanalysis of the MTC prediction would be required?APS Response If plans were made to operate in a condition beyond that which was evaluated in the reload analysis, then an additional evaluation would be performed to validate that the limits of LCO 3.1.4 would not be challenged by the planned change. If the analysis performed for the off normal operation, including appropriate biases and uncertainties, predicted that MTC would exceed the LCO limit, then a revised operating plan would be needed to operate at less challenging conditions such that the predicted MTC will not challenge the LCO limits.2