ML19092A317
| ML19092A317 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 04/11/2019 |
| From: | Perry Buckberg Plant Licensing Branch II |
| To: | Nazar M Florida Power & Light Co |
| Buckberg P, 301-415-1383 | |
| References | |
| EPID L-2019-LR0-0003 | |
| Download: ML19092A317 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION Mr. Mano Nazar President, Nuclear Division and Chief Nuclear Officer Florida Power & Light Company WASHINGTON, D.C. 20555-0001 April 11, 2019 700 Universe Blvd., Mail Stop EX/JB Juno Beach, FL 33408
SUBJECT:
SUMMARY
OF CONFERENCE CALL WITH TURKEY POINT NUCLEAR GENERATING REGARDING UNIT NO. 4 SPRING STEAM GENERATOR INSPECTIONS (EPID L-2019-LR0-0003)
Dear Mr. Nazar:
On March 22, 2019, the U.S. Nuclear Regulatory Commission staff participated in a conference call with representatives of Florida Power and Light Company regarding the ongoing Turkey Point Nuclear Generating Station Unit No. 4 steam generator inspections.
A list of the conference call participants is contained in Enclosure 1. A list of questions and responses discussed during the call are in Enclosure 2.
If you have any questions regarding this summary, please contact me at 301-415-1383, or at Perry. Buckberg@nrc.gov.
Docket No. 50-251
Enclosure:
- 1. List of Participants
- 2. Conference Call Summary cc: Listserv Sincerely, 9
Lenior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
LIST OF PARTICIPANTS MARCH 22, 2019, CONFERENCE CALL WITH FLORIDA POWER AND LIGHT COMPANY TURKEY POINT NUCLEAR GENERATING UNIT NO. 4 SPRING 2019 STEAM GENERATOR INSPECTIONS Nuclear Regulatory Commission Andrew Johnson Alan Huynh Perry Buckberg Robert Carrion Florida Power & Light Company Kester Thompson Ed Korkowski Claude Ford Chris Geiser Brian Dunn Olga Hanek lntertek Russ Cipolla
CONFERENCE CALL
SUMMARY
TURKEY POINT NUCLEAR GENERATING UNIT NO. 4 STEAM GENERATOR TUBE INSPECTIONS DOCKET NO. 50-251 On March 22, 2019, U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with Florida Power and Light Company (the licensee), regarding the ongoing steam generator (SG) tube inspection activities at Turkey Point Nuclear Generating Unit No. 4 during Refueling Outage 31.
Turkey Point Unit No. 4 has three Westinghouse Model 44F SGs; SG A, SG B and SG C.
These SGs, were placed in service in 1983; each SG has 3,214 thermally treated Alloy 600 tubes. The tubes are supported by stainless steel tube support plates {TSPs) with quatrefoil-shaped holes and V-shaped anti-vibration bars (AVBs). In addition to the depth-based tube repair criteria, the licensee is authorized to leave flaws within the tubesheet region in service provided they satisfy the H* alternate repair criterion.
Information provided by the licensee during the conference call is summarized below:
No indications of primary-to-secondary leakage were observed during the recently completed cycle. No secondary side pressure tests were performed during the outage.
No exceptions were taken to the industry guidelines. No in-situ pressure tests or tube pulls were planned.
Inspections were performed in all three SGs. At the time of the call, the licensee stated that approximately 99 percent of the inspections were completed. Based on the expansion criteria in the degradation assessment and the inspection results, no expansion inspections were added to the inspection scope. The inspection scope included:
o 100-percent full length bobbin examinations in all tubes except row 1-2 U-bends o
+Point' examinations of row 1-2 U-bends o
Array probe examinations in the hot leg tubesheet region o
Array examinations in periphery tubes (two-tubes deep) along the annulus and the no-tube lane for foreign objects (FOs) o
+Point' sample examinations in row 1-2 U-bends o
+Point' special interest examinations o
+Point' high stress tube (low-voltage offset) examinations Only wear was identified during the outage. There were 83 AVB wear indications, with the largest sized at 32-percent through-wall (TW), 8 flow distribution baffle plate wear indications, with the largest sized at 11-percent TW, 6 TSP wear indications, with the largest sized at 17-percent TW, and 1 case of FO wear in SG B sized at 31-percent TW.
No new type of degradation was identified. No indications of corrosion were identified.
Candidates for tube plugging are based on the results of operational assessment. In addition to tubes that exceed the plugging limit of 40-percent TW, tubes that exhibit large growth between outages (e.g., indications that grow from below the detection threshold to greater than 30-percent TW) and tubes that require preventative plugging due to the detection/presence of FOs, are to be plugged. At the time of the conference call, the licensee planned to plug four tubes (rows 28-29, columns 34-35) due to the presence of a FO.
The licensee performs array probe examinations on peripheral tubes and the no-tube lane to detect loose parts. The licensee also performs visual inspections on a sample of six columns in each leg (i.e., hot leg, cold leg). Previously identified possible loose-part locations are also inspected.
Loose-parts examinations were still scheduled to be completed in SG A at the time of the call. In SG B, two pre-existing FOs were visually confirmed, with one having migrated over several columns. In addition, four new FOs were identified, with three identified as sludge rocks and one as a threaded bolt, which is the reason four tubes were going to be plugged. In SG C, the licensee identified three pre-existing FOs, visually confirmed one of them, but could not visually confirm the other two. The licensee identified two new metallic FOs and retrieved both. As previously discussed, one indication of FO wear was identified in SG B with no object present.
Sludge lancing is still scheduled to be performed in SG A. Approximately 30 pounds and 49 pounds of sludge were removed from SGs B and C, respectively. Upper bundle visual inspections searching for blockage due to deposit loading were still scheduled to be performed in all SGs. Feedring and upper internals inspections are scheduled to be performed in SG B only.
The remaining examinations during the outage include:
o 20 special interest bobbin examinations, 30 +Point' exams, and 25 ding exams inSGA o
1 cold leg periphery array examination and 1 restricted tube exam in SG B o
5 special interest ding examinations in SG C o
Upper bundle flush, sludge lancing, and foreign object search and retrieval in SGA o
Upper bundle and upper internals inspections in SG B The NRC staff did not identify any issues that required followup action at this time, however, the NRC staff asked to be notified in the event that any unusual conditions were detected during the remainder of the outage.
ML19092A317 OFFICE NRR/DORL/LPL2-2/PM NRR/DORL/LPL2-2/LA NAME PBuckberg BClayton DATE 4/8/2019 4/4/2019 OFFICE NRR/DORL/LPL2-2/BC NRR/DORL/LPL2-2/PM NAME UShoop PBuckberg DATE 4/10/2019 4/11/2019