ML20073F383

NRR E-mail Capture - Request for Additional Information - Catawba Nuclear Station - SG Report (RA-19-0391) - C2R23

ML20073F383
Person / Time
Site:	Catawba
Issue date:	03/13/2020
From:	Michael Mahoney NRC/NRR/DORL/LPL2-1
To:	Edwards N Duke Energy Carolinas
References
Download: ML20073F383 (2)

Text

From: Mahoney, Michael Sent: Friday, March 13, 2020 7:43 AM To: 'Edwards, Nicole D' Cc: Arthur.Zaremba@duke-energy.com

Subject:

Request for Additional Information -Catawba Nuclear Station - SG Report (RA-19-0391) - C2R23

Nicole, By letter RA-19-0391, dated December 19, 2019 (Agencywide Documents Access and Management System Accession No. ML19353A416), Duke Energy (the licensee) submitted information summarizing the results of the fall 2019 steam generator inspections performed at Catawba Nuclear Station, Unit 2. These inspections were performed during refueling outage 23 (RFO 23). A report from each steam generator inspection is submitted to the U. S. Nuclear Regulatory (NRC) in accordance with the plant Technical Specifications (TS).

The NRC staff has reviewed the application and, based upon this review, determined that additional information is needed to complete our review. Please provide a response on the docket within 30 days of this correspondence.

Request for Additional Information (RAI-01)

The tube at Row 31 Column 33 (R31C33) in Steam Generator 2A (SG 2A) was plugged during refueling outage 23 (RFO 23) due to an eddy current indication of axial cracking just above the 3H tube support plate. The tube inspection report states that the indication met the condition monitoring criteria for leakage because the eddy current voltage was less than the threshold voltage for leakage. In this case, the measured voltage was being compared to a screening criterion for axial outside diameter stress corrosion cracking (ODSCC) in the EPRI Steam Generator In-Situ Pressure Test Guidelines. In the tube inspection report, this single axial indication (SAI) lists two voltage measurements of 2.05 V and 2.09 V from Channel P4.

a. For in-situ pressure-test screening, the EPRI Guidelines provide +Point probe threshold voltage values for the 300 kHz analysis frequency. What was the 300 kHz voltage for this flaw?

b. Please describe the frequency or frequencies used for Channel P4 and how Channel P4 relates to the 300 kHz signal in terms of performing the screening.

c. If the 300 kHz voltage exceeds the threshold value, discuss how this flaw would be processed through the in-situ pressure test guidelines.

Once this email is added to ADAMS, I will provide the accession number for your reference.

Thanks Mike Michael Mahoney McGuire and Catawba Project Manager, Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Desk: (301)-415-3867 Email: Michael.Mahoney@NRC.GOV

Hearing Identifier: NRR_DRMA Email Number: 477 Mail Envelope Properties (BL0PR0901MB3266E199B146199F185F62DBE5FC0)

Subject:

Request for Additional Information -Catawba Nuclear Station - SG Report (RA-19-0391) - C2R23 Sent Date: 3/13/2020 7:42:52 AM Received Date: 3/13/2020 7:42:54 AM From: Mahoney, Michael Created By: Michael.Mahoney@nrc.gov Recipients:

"Arthur.Zaremba@duke-energy.com" <Arthur.Zaremba@duke-energy.com>

Tracking Status: None

"'Edwards, Nicole D'" <Nicole.Edwards@duke-energy.com>

Tracking Status: None Post Office: BL0PR0901MB3266.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 2379 3/13/2020 7:42:54 AM Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: