L-2017-119, License Renewal Commitments, Reactor Vessel Internals Aging Management Plan

License Renewal Commitments, Reactor Vessel Internals Aging Management Plan

ML17186A044
Person / Time
Site:	Saint Lucie
Issue date:	07/03/2017
From:	Deboer D Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2017-119, TAC MF6777, TAC MF6778
Download: ML17186A044 (2)

Text

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U.S. Nuclear Regulatory Commission Document Control Desk JUL 0 3 2017 L-2017-119 10 CFR 54 Washington, D .C. 20555-0001 St. Lucie Units 1 and 2 Docket Nos. 50-335 and 50-389

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Reactor Vessel Internals Aging Management Plan Reference

1. FPL Letter from Christopher Costanzo to U.S. Nuclear Regulatory Commission (L-2015-229) "St. Lucie Units 1 and 2 Docket Nos. 50-335 and 50-389, License Renewal Commitments- Reactor Vessel Internals Aging Management Plan," Dated September 28, 2015.

2. NRC e-Mail from Perry Buckberg to Ken Frehafer, Request for Additional Information, St. Lucie Plant Units 1 and 2, Reactor Vessel Internals Aging Management Plan, Docket Nos. 50-335 and 50-389, TAC Nos. MF6777 and MF6778.

3. FPL Letter from Christopher Costanzo to U.S. Nuclear Regulatory Commission (L-2015-040), Reactor Vessel Internals Aging Management Plan, dated February 26, 2016.

4. FPL Letter from Daniel DeBoer to U.S. Nuclear Regulatory Commission (L-2017-015), Reactor Vessel Internals Aging Management Plan, dated March 7, 2017.

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated September 28, 2015 (Reference 1), Florida Power & Light Company (FPL) submitted its License Renewal Reactor Internals Inspection Program in accordance with MRP-227A at St. Lucie Nuclear Plants Units 1 and 2, for NRC staff review. The NRC staff reviewed the information provided by FPL in its submittal and requested additional information to complete their review (Reference 2). The responses to RAI-l through RAI-10 were previously submitted to the NRC on February 26, 2016 (Reference 3) and March 7, 2017 (Reference 4).

In References 3 and 4 noted above, FPL noted that PWR Owners Group (PWROG) was developing a Generic Response Report for RAI-9. FPL response to RAI-9 is noted below:

PSLRAI-9:

Applicant/ Licensee Action Item (A/ LAI) 7 requires an applicant or licensee to provide an evaluation demomtrating that mst austenitic stainless steel (Cr:I.SS) RVI components will maintain theirfunctionaliry throughout the period if extmded operation (PEO), considering the potentia/loss iffradure toughness due to both thmnal embrittlement (TE) and irradiation embrittlement (IE). In its response to A/ LAI 7, the licensee identified the R VI components that are fabricated from CASSasSt. Lucie P!ant Unit 1 core suppo1t columns, the CEA shroud tubes for both units, and the St. Lucie P!ant Unit 2 flow l?Jpass itt.rerts.

The licensee ittdimted that all but one if the Unit 1 core supp01t columns m*een in forTE based on the assumption that the columns have fene'te > 20%, since mtified material test reports could not be located for these columns.

The licensee then concluded that the results if this evaluation do not conflict with strategy for aging management ifR VI provided itt MRP-22 7-A. The licensee stated that it is concluded that continued application if the strategies in MRP-2 27-A and the St.

Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957

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L-2017-119 10 CFR 54 Page 2 of2 Lucie P!ant Units 1 and 2 R VI Inspection Program will meet the requirements for managing age-related degradation of St.

Lucie Plant Units 1 and 2, CASS and mmtensitic stainless steel RVI components. However, the licensee did notprovide any justification for its position that the MRP-22 7A aging management requirements (which require no inspections of the core support columns) are sufficient, considering the potentialfor loss offincture toughness due to two mechanisms, and the susceptibility to cracking of the columns. The staff notes that the core supp011 column welds, which are visible from above the core support plate, are inspected as Primm)' components, butMKP~"""27-A and tbe St. LUcze Plant Onzt IR:Vi ./:fMP.--:n-

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zn expansion to the columns if degradation is detected in the welds.

Since the St. Lucie Plant Unit 1 core supp011 columns (except one) are screened in forTE, and are also susceptible to IE and several cracking mechanisms, the stciff requests the licensee provide an evaluation for St. Lucie Plant Unit 1, demonstrating that the core supp011 columns will remain functional during the PEO considering the potential combined loss ofjiwture toughness due to IE plus IE, along with the potentialfor cracking in the columns.

FPL Response:

The response to RAI-9 described the on-going work by the PWROG for the CASS lower support column welds functionality analysis on a generic basis. Westinghouse, on behalf ofPWROG, has completed the functionality analysis in Report No. PWROG-14048-P, Revision 1 (Proprietary). This report demonstrates the functionality of St. Lucie Unit 1 CASS core support columns (on a generic basis), during the period of extended operation, considering the loss of fracture toughness due to both thermal embrittlement (TE) and irradiation embrittlement (IE).

Report No. PWROG-14048-P, Revision 1 was submitted to the NRC by the Owners Group via OG Letter No. OG-17-62 dated March 1, 2017. This report is currently under NRC review.

This letter is to acknowledge that FPL has reviewed PWROG-14048-P, Revision 1 and concurs that the conclusions noted in the Executive Summary and Section 7 are applicable to St. Lucie Nuclear Plant, Unit 1.

No changes to tl1e PSL RV Internals Aging Management Program as submitted to the NRC in Reference 4 are needed.

By submittal of this letter, FPL has completed responses to all ten NRC RAis on the Reactor Vessel Inspection Program described in reference 2.

Should you have any questions, please contact Mr. Michael Snyder, Licensing Manager, at 772-467-7036.

Very truly yours, Daniel DeBoer Site Director St. Lucie Plant DD/lrb Cc: USNRC Regional Administrator, Region II USNRC Senior Resident Inspector, St. Lucie Units 1 and 2