L-2013-002, Response to NRC Request for Additional Information Regarding License Amendment Request No. 224 on Technical Specification 3/4.6.2.3 - Recirculation Ph Control System and Natb Basket Minimum Loading Requirement

Response to NRC Request for Additional Information Regarding License Amendment Request No. 224 on Technical Specification 3/4.6.2.3 - Recirculation Ph Control System and Natb Basket Minimum Loading Requirement

ML13015A005
Person / Time
Site:	Turkey Point
Issue date:	01/11/2013
From:	Kiley M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2013-002
Download: ML13015A005 (5)

Text

L-2013-002 10 CFR 50.90 JAN 1 1 2013 FPL.

U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, D.C. 20555-0001 Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Response to NRC Request for Additional Information Regarding License Amendment Request No. 224 on Technical Specification 3/4.6.2.3 -

Recirculation pH Control System and NaTB Basket Minimum Loading Requirement

References:

(1) M. Kiley (FPL) to U.S. Nuclear Regulatory Commission (L-2012-314), "License Amendment Request No. 224 Regarding Technical Specification 3/4.6.2.3 - Recirculation pH Control System and NaTB Basket Minimum Loading Requirement," Accession No. ML12251A249, September 6, 2012.

(2) Email from Tracy Orf (NRC) to Olga Hanek (FPL), "Draft RAIs re: Sump pH LAR,"

November 30, 2012.

By letter L-2012-314 dated September 6, 2012 [Reference 1], Florida Power & Light Company (FPL) requested to amend Renewed Facility Operating Licenses DPR-31 and DPR-41 and revise the Turkey Point Units 3 and 4 Technical Specifications (TS). The proposed amendment will decrease the minimum required mass of sodium tetraborate decahydrate (NaTB) specified in TS Surveillance Requirement 4.6.2.3 from 11,061 lbms to 7,500 lbms in order to lessen the long term sump pH profile, recover design margin, and facilitate NaTB basket loading and maintenance.

TS 3.6.2.3 addresses the requirements for the Recirculation pH Control System which is a passive safeguard consisting of ten stainless steel wire mesh baskets located in the containment basement and containing a total of at least 11,061 Ibm of NaTB. This passive system assures that there is sufficient NaTB available in the containment to ensure a sump pH greater than 7.0 at the onset of the recirculation phase of a postulated loss-of-coolant accident (LOCA).

By email from the U.S. Nuclear Regulatory Commission (NRC) Project Manager (PM) dated November 30, 2012 [Reference 2], additional information regarding the effects of the proposed reduction in basket loading was requested by the staff in NRC's Steam Generator Tube Integrity and Chemical Engineering Branch (ESGB) to support review of the NaTB License Amendment Request (LAR). The RAI consisted of two (2) questions regarding the projected post-LOCA minimum sump pH profile for 7,500 lbms and the impact of this reduced NaTB loading on post-LOCA chemical precipitate generation. On December 11, 2012, a meeting was held between FPL and NRC representatives to discuss these questions. Based on this discussion, the two RAI questions and the applicable FPL responses are provided in the Attachment to this letter.

This submittal does not alter the significant hazards consideration or environmental assessment previously submitted by FPL letter L-2012-3 14 [Reference 1].

This submittal contains no new commitments and no revisions to existing commitments.

Florida Power & Light Company 9760 SW 344 St., Florida City, FL 33035

Turkey Point Units 3 and 4 L-2013-002 Docket Nos. 50-250 and 50-251 Page 2 of 2 In accordance with 10 CFR 50.91(b)(1), a copy of this letter is being forwarded to the State Designee of Florida.

Should you have any questions regarding this submittal, please contact Mr. Robert J. Tomonto, Licensing Manager, at (305) 246-7327.

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

Executed on January //, 2013.

Very truly yours, Michael Kiley Site Vice President Turkey Point Nuclear Plant Attachment cc: USNRC Regional Administrator, Region II USNRC Project Manager, Turkey Point Nuclear Plant USNRC Senior Resident Inspector, Turkey Point Nuclear Plant Ms. Cindy Becker, Florida Department of Health Florida Power &Light Company 9760 SW 344 St., Florida City, FL 33035

Turkey Point Units 3 and 4 L-2013-002 Docket Nos. 50-250 and 50-251 Attachment Page 1 of 3 Turkey Point Units 3 and 4 Response to NRC Request for Additional Information Regarding License Amendment Request No. 224 on Technical Specification 3/4.6.2.3 -

Recirculation pH Control System and NaTB Basket Minimum Loading Requirement ATTACHMENT

Turkey Point Units 3 and 4 L-2013-002 Docket Nos. 50-250 and 50-251 Attachment Page 2 of 3 Response to Request for Additional Information The following information is provided by Florida Power & Light Company (FPL) in response to the U. S. Nuclear Regulatory Commission's (NRC) Request for Additional Information (RAI). This information was requested to support License Amendment Request (LAR) No. 224, TS 3/4.6.2.3 -

Recirculation pH Control System and NaTB Basket Minimum Loading Requirement, for Turkey Point Nuclear Plant (PTN) Units 3 and 4 that was submitted to the NRC by FPL letter L-2012-314 on September 6, 2012 [Reference 1].

In an email dated November 30, 2012 [Reference 2], the NRC staff requested additional information regarding FPL's request to implement the proposed reduction in NaTB basket loading under LAR 224. The RAI consisted of two (2) questions from the NRC's Steam Generator Tube Integrity and Chemical Engineering Branch (ESGB) regarding the projected post-LOCA minimum sump pH profile at 7,500 lbms and impact of this reduced NaTB loading on post-LOCA chemical precipitate generation. On December 11, 2012, a telephone call was held between FPL and NRC representatives to discuss these questions. Based on the discussion, the two RAI questions and the applicable FPL responses are documented below.

ESGB-1 License amendment request (LAR) 224 dated September 6, 2012 (ADAMS Accession No. ML12251A249) indicates that a minimum 7500 Ibm sodium tetraborate decahydrate (STB) basket loading will ensure sump pH remains above 7.0 throughout the recirculation phase of a loss of coolant accident. Please provide a plot of sump pH profile as a function of time assuming 75001bm STB and plant conditions that would result in a minimum p11 profile. In addition, either confirm that the methodology used to calculate pH was the same as provided to the NRC in letter dated April 28, 2010 (Accession No. ML101200063) or describe the differences.

9.0 Sump pH for Case 8 8.5 8.0 7.5 7.0- / 2725 seo,7,045 pH 6.5 6.0 5.5 5.0 4.5 4 .0 -.. .. ..

10 100 1000 10000 100000 1000000 10000000 Time (sec)

Figure 1: Minimum Sump pH curve with 75001bs NaTB in sump baskets.

Turkey Point Units 3 and 4 L-2013-002 Docket Nos. 50-250 and 50-251 Attachment Page 3 of 3 The methodology, i.e., Palmer Method, used to calculate the minimum sump pH profile above is the same as that provided to the NRC in FPL letter L-2010-082 dated April 28, 2010 [Reference 3].

ESGB-2 The LAR also indicates that by reducing the STB quantity and therefore peak pH, the post-accident chemical precipitate generation is reduced. Please discuss the quantity of precipitate reduction associated with reducing the peak pH values. For example, providing a quantity of precipitates calculated by the WCAP-16530-NP-A method for a peak pH of 8.01 as compared to a pH of 7.68 would be one way to respond to this question.

As indicated in FPL letter L-2012-3 14 [Reference 1], the proposed reduction in the total TS required mass of NaTB in the baskets from 11,061 lbms to 7,500 lbms will decrease the peak sump pH to approximately 7.680. Preliminary analyses of the post-LOCA chemical precipitate generation using the above WCAP methodology for these two cases will reduce the quantity of chemical precipitate generated by approximately 6.5% for Unit 3 and approximately 5.2% for Unit 4.

References

1. M. Kiley (FPL) to U.S. Nuclear Regulatory Commission (L-2012-314), "License Amendment Request No. 224 Regarding Technical Specification 3/4.6.2.3 - Recirculation pH Control System and NaTB Basket Minimum Loading Requirement," Accession No. ML12251A249, September 6, 2012.

2. Email from Tracy Orf (NRC) to Olga Hanek (FPL), "Draft RAIs re: Sump pH LAR,"

November 30, 2012.

3. M. Kiley (FPL) to U.S. Nuclear Regulatory Commission (L-2010-082), "Supplement to License Amendment Request 196 (ADAMS Accession No. ML092050112) - Revised Summary of Turkey Point Sump pH Calculation Inputs, Assumptions, Methodology, and Results," Accession No. ML101200063, April 28, 2010.