L-2019-056, Inservice Inspection Plan RAI Reply, Fifth Ten-Year Interval Unit 1 Relief Request

Inservice Inspection Plan RAI Reply, Fifth Ten-Year Interval Unit 1 Relief Request

ML19066A011
Person / Time
Site:	Saint Lucie
Issue date:	03/07/2019
From:	Synder M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2019-056
Download: ML19066A011 (3)

Text

MAR 0 7 2019 L-2019-056 10 CFR 50.4 10CFR 50.55a U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Re: St. Lucie Unit 1 Docket No. 50-335 Inservice Inspection Plan RAI Reply Fifth Ten-Year Interval Unit 1 Relief Request 6

Reference:

1. FPL Letter L-2018-162 dated August 31, 2018, "Inservice Inspection Plan Fifth Ten-Year Interval Unit 1 Relief Request 6." ADAIVIS Accession No. ML18243A030

2. FPL Letter L-2018-188 dated September 28, 2018, "Inservice Inspection Plan Fifth Ten-Year Interval Unit 1 Relief Request 6." ADAIVIS Accession No. ML18271A093

3. Email from Schaaf to Frehafer dated February 1, 2019, "St. Lucie Plant Unit No.1- Draft Request for Additional Information Related to Relief Request 6 Regarding the Refueling Water Tank Bottom Liner (EPID L-2018-LLR-0116)"

In Reference 1 and as supplemented by Reference 2, FPL requested Code relief for the continued use of the reinforced vinyl ester liner on the bottom of the Unit 1 Refueling Water Tank (RWT) that was installed in 1994. In Reference 3, the NRC requested additional information to complete their review of the application. Note that the requested 30 day response date was extended via discussion with the Project Manager and FPL. The attachment to this letter provides FPL's response.

Please contact Ken Frehafer at (772) 467-7748 if there are any questions about this submittal.

Very truly yours, Michael]. Snyder Licensing Manager St. Lucie Plant MJS/KWF Attachment cc: St. Lucie NRC Program Manager, USNRC Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957

L-2019-056 Attachment Page 1 of 2 FPL RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI) QUESTION RELIEF REQUEST 6 REGARDING THE REFUELING WATER TANK BOTTOM LINER (EPID: L-2018-LLR-0116)

FPL installed a reinforced vinyl ester liner on the bottom of the Unit 1 Refueling Water Tank (RWT) in 1994. The NRC has previously approved the use of this liner as an alternative non-Code repair through the fourth ten-year in-service inspection (ISI) interval. Relief Request 6 was submitted via Reference 1 for the fifth ten-year ISI interval of St. Lucie Unit 1.

The NRC staff has reviewed the information provided by FPL in Reference 1, and has determined that additional information is required to complete the review of the Relief Request.

One Request for Additional Information (RAI) Question (EPID: L-2018-LLR-0116) was provided by the NRC to FPL via Reference 2. The question, and FPLs response to this question is provided below:

NRC QUESTION No. 1 On page 10 of the relief request, the licensee indicated that cracks were detected on the liner as part of the remote visual inspection performed during the last refueling outage of the fourth interval (Refueling Outage SL1-28). Please discuss a plan regarding repair activities for the liner cracks (e.g., when the repair will be performed and the repair method). As part of the response, discuss the criteria that will be used to determine whether the cracks will be repaired and the basis for the criteria.

FPL RESPONSE Prior to the first hands on inspection of the Unit 1 Refueling Water Tank Bottom during SL1-20, an Engineering Evaluation (Reference 5) was prepared to provide the procedures and repair contingencies. The documentation of the SL1-20 inspection and the application of the associated criteria and repair activities was documented by FPL to the NRC in Reference 3 as part of the fourth ten-year inspection interval acceptance (Reference 4). The same repair activities, inspection and acceptance criteria will be used during SL1-29. The RAI question was separated into two parts to address the repair activities and basis for repair criteria separately.

What is plan regarding repair activities for the liner cracks (e.g., when the repair will be performed and the repair method)?

During the upcoming Refueling Outage (SL1-29), the Unit 1 Refueling Water Tank will be drained and complete hands on inspection of the tank bottom liner, including the areas identified as part of the remote visual inspection during Refueling Outage SL1-28, will be performed. Any required repairs are to be performed during the outage and in accordance with the repair contingencies per Reference 5, Attachment 3.

For cracking, the repair contingencies require that the crack be prepped for repair by being profiled into a V shape and sanded 1 inch (minimum) into the surrounding liner material. The repair of the prepared area shall be made by applying one coat of Duromar SAR-UW. The Duromar shall extend a minimum of 1 onto the existing sound liner material surrounding the crack.

L-2019-056 Attachment Page 2 of 2 Discuss the criteria that will be used to determine whether the cracks will be repaired and the basis for the criteria.

The acceptance criteria and detailed description of the post installation inspection procedures are identified in Reference 5, Attachment 1.

Per Section 7.6.6 of this guidance states:

Cracking is defined as small breaks in the liner which extend from the surface to the substrate.

Inspection for cracking shall be by visual examination. Visual standards contained in ASTM D661 may be used as a guide to evaluate the degree of cracking.

Where cracking is observed, the area of cracking shall be excavated with a knife (or other suitable tool) to determine the depth of the crack. Areas of cracking shall be marked and photographed.

Per Section 8.2.6, of this guidance the acceptance criterion for cracking is that the liner shall be considered acceptable if there are no areas of cracking observed. Based on this criterion all cracking will be repaired.

References:

1. FPL Letter L-2018-162, Dated August 31, 2018 (Subj: Fifth Ten-Year Interval Unit 1 Relief Request 6)

2. Email from Robert Schaaf (NRC) to Ken Frehafer (FPL), dated February 1, 2019.

3. FPL Letter L-2008-079, Dated April 9, 2008 (Subj: fourth Ten-Year Interval Unit 1 Relief Request 3.)

4. Letter from Thomas H. Boyce (NRC) to Mr. Mano Nazar (FPL), dated February 12, 2009

[Subj: St. Lucie Plant, Unit 1 - Relief Request No. 3, Request for Alternative to ASME Code,Section XI Repair Requirements for Refueling Water Tank Bottom (TAC No.

MD9268].

5. Engineering Evaluation No. PSL-ENG-SECS-05-053, Revision 1 Inspection Procedures and Repair Contingencies for the Refueling Water Tank Bottom Liner (SL1-20).