ML12094A310

St. Lucie, Unit 1, Response to NRC Reactor Systems Branch Request for Additional Information Regarding Extended Power Uprate License Amendment Request

ML12094A310
Person / Time
Site:	Saint Lucie
Issue date:	03/31/2012
From:	Anderson R L Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2012-146
Download: ML12094A310 (3)

Text

0 Florida Power & Light Company, 6501 S. Ocean Drive, Jensen Beach, FL 34957 FPDL March 31, 2012 L-2012-146 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Re: St. Lucie Plant Unit 1 Docket No. 50-335 Renewed Facility Operating License No. DPR-67 Response to NRC Reactor Systems Branch Request for Additional Information Regarding Extended Power Uprate License Amendment Request

References:

(1) R, L. Anderson (FPL) to U.S. Nuclear Regulatory Commission (L-2010-259),"License Amendment Request (LAR) for Extended Power Uprate," November 22, 2010, Accession No. ML1 03560419.By letter L-2010-259 dated November 22, 2010 [Reference 1], Florida Power & Light Company (FPL) requested to amend Renewed Facility Operating License No. DPR-67 and revise the St. Lucie Unit 1 Technical Specifications (TS). The proposed amendment will increase the unit's licensed core thermal power level from 2700 megawatts thermal (MWt) to 3020 MWt and revise the Renewed Facility Operating License and TS to support operation at this increased core thermal power level. This represents an approximate increase of 11.85% and is therefore considered an Extended Power Uprate (EPU).During a conference call on March 26, 2012, the NRC Project Manager identified a request for additional information (RAI) from the NRC staff in the Reactor Systems Branch (SRXB) related to St. Lucie Unit I vessel flux reduction assemblies (VFRAs) to support their review of the EPU License Amendment Request (LAR). The response to this RAI is provided in the Attachment to this letter.In accordance with 10 CFR 50.91 (b)(1), a copy of this letter is being forwarded to the designated State of Florida official.This submittal does not alter the significant hazards consideration or environmental assessment previously submitted by FPL letter L-2010-259

[Reference 1].an FPL Group company L-2012-146 Page 2 of 2 This submittal contains no new commitments and no revisions to existing commitments.

Should you have any questions regarding this submittal, please contact Mr. Christopher Wasik, St. Lucie Extended Power Uprate LAR Project Manager, at 772-467-7138.

I declare under penalty of perjury that the foregoing is true and correct to the best of my knowledge.

Executed on 3)- a'o- I2.Very truly yours, Richard L. Anderson Site Vice President St. Lucie Plant Attachment cc: Mr. William Passetti, Florida Department of Health L-2012-146 Attachment Page 1 of 1 Response to NRC Reactor Systems Branch Request for Additional Information The following information is provided by Florida Power & Light (FPL) in response to the U. S.Nuclear Regulatory Commission's (NRC) Request for Additional Information (RAI). This information was requested to support the Extended Power Uprate (EPU) License Amendment Request (LAR) for St. Lucie Unit 1 submitted to the NRC by FPL via letter L-2010-259 dated November 22, 2010, Accession Number ML1 03560419.During a conference call on March 26, 2012, the NRC Project Manager identified a request for additional information (RAI) from the NRC staff in the Reactor Systems Branch (SRXB) related to St. Lucie Unit 1 vessel flux reduction assemblies (VFRAs). FPL designated the question as SRXB-64; the response is provided below.RAI SRXB-64 Provide justification why vessel flux reduction assemblies can be placed in any location in the spent fuel pool designated for a fuel assembly.Response Vessel flux reduction assemblies (VFRAs) were used in St. Lucie Unit 1 between operating cycles 11 and 14 (years 1991 through 1997). The VFRAs accumulated burnups less than 3600 MWD/MTU of exposure.

Since calculations showed that their reactivity slightly increased with burnup, they were conservatively evaluated at approximately 4000 MWD/MTU to bound actual exposures.

After depleting up to the noted exposure with hafnium rods inserted, the hafnium rods were removed to establish a bounding reactivity value. No credit is taken for their cooling times in the spent fuel pool (>10 years).Additionally, a fuel assembly with 1.9 wt % U 2 3 5 (20,000 MWD/MTU burnup) was evaluated and compared to the VFRAs with and without hafnium rods. The exposure for the 1.9 wt % U 2 3 5 fuel assembly was selected based on the exposure required for case 6 (fuel type 5) fuel assemblies at that enrichment.

Case 6 represents the lowest reactivity class fuel in the criticality analysis presented in the EPU LAR.The VFRAs (with and without hafnium) were found to have reactivities (k-=) that remained below the assembly with 1.9 wt % U 2 3 5 , as shown in the table below: VFRA with wih hhafnium rods 1.9 wt % U 2 3 5 with hafnium reoe ________removed Burnup (MWD/MTU) 4,050 4,050 20,000 k. 0.60323 0.91858 0.99905 Based on the above, VFRA assemblies are qualified for any location that may contain a fuel assembly in the spent fuel pool.