ML092710081
| ML092710081 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 09/24/2009 |
| From: | Siva Lingam Plant Licensing Branch II |
| To: | Mashburn F, Proffitt J Tennessee Valley Authority |
| Lingam, S NRR/DORL 415-1564 | |
| References | |
| TAC ME1343 | |
| Download: ML092710081 (2) | |
Text
From:
Lingam, Siva Sent:
Thursday, September 24, 2009 8:36 AM To:
'fcmashburn@tva.gov'; 'Proffitt, James W Jr' Cc:
Boyce, Tom (NRR); Karwoski, Kenneth; Johnson, Andrew
Subject:
Sequoyah, Unit 2 LAR - Revise TSs to allow ST Tubing ARC (W*) (TAC No.
ME1343)
We have reviewed your RAI responses dated August 14, 2009, for the subject LAR, and we need further clarifications for the following. Please provide your responses. In case you want to discuss, we can arrange a conference call today at noon or 4:00 PM; or tomorrow at 8:00 AM.
- 1. Based on your responses to RAIs 4 and 5 and Commitment 2, it is not clear how you will implement the accident induced leakage methodology. For example, will the Row 1 tubes always be assumed to leak at 0.00009 gpm regardless of whether flaws are detected in the top portion of the tubesheet? When no flaws are detected in the uppermost 10.5 inches of tubing in the tubesheet, will the four assumed flaws be multiplied by 10% and then by 0.0045 gpm to arrive at the accident induced leakage for the portion of tube between 10.5 and 12 inches from the top of the tubesheet? If flaws are detected in the uppermost 10.5 inches, what assumptions will be made concerning the number of flaws in the tube-ends in the tubes other than row 1?
Please clarify commitment 2 regarding your accident induced leakage methodology for when indications are, and are not, detected in the cold-leg.
- 2. In your response to RAIs 4 and 5, you describe your inspection sample expansion criteria for when flaws are detected. Given that this expansion criteria is important in projecting the amount of accident induced leakage for the portion of the tube in the tubesheet in the cold-leg, please discuss your plans to commit to this inspection sample expansion criteria (i.e., the initial 20 percent sample will be expanded to 100 percent upon finding an indication in the cold leg tubesheet region, and if an indication is found in the 100 percent expansion, 100 percent of all of the tubes in the other steam generators will be inspected).
- 3. Please clarify Commitment 1 since it is not clear whether the 2.88 inches already includes the uncertainty associated with measuring the inspection distance from the top of the tubesheet or whether an additional adjustment will be made to the 2.88 inches to account for the uncertainty in the measurement.
In addition, Commitment 1 does not address actions to be taken if the bottom of the expansion transition on a cold leg tube is found to be greater than 2.88 inches below the top of the tubesheet. Please discuss your plans to modify Commitment 1 to indicate what will be done if the bottom of expansion transition is greater than 2.88 inches below the top of the tubesheet and to report this condition to the NRC via the Steam Generator Tube Inspection Report.
- 4. Please discuss your plans to report tube slippage, if it occurs. Plants implementing other alternate repair criteria, such as H*, will report slippage, if it occurs.
Siva P. Lingam U.S. Nuclear Regulatory Commission Project Manager (NRR/DORL/LPL2-2)
Sequoyah Nuclear Plant Location: O8-D5; Mail Stop: O8-G9a
Telephone: 301-415-1564; Fax: 301-415-1222 E-mail address: siva.lingam@nrc.gov E-mail Properties Mail Envelope Properties ()
Subject:
Sequoyah, Unit 2 LAR - Revise TSs to allow ST Tubing ARC (W*) (TAC No. ME1343)
Sent Date: 9/24/2009 8:26:00 AM Received Date: 9/24/2009 8:35:00 AM From: Lingam, Siva Created By: Siva.Lingam@nrc.gov Recipients:
fcmashburn@tva.gov ('fcmashburn@tva.gov')
Tracking Status: None jwproffitt@tva.gov ('Proffitt, James W Jr')
Tracking Status: None Tom.Boyce@nrc.gov (Boyce, Tom (NRR))
Tracking Status: None Kenneth.Karwoski@nrc.gov (Karwoski, Kenneth)
Tracking Status: None Andrew.Johnson@nrc.gov (Johnson, Andrew)
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 14721 9/24/2009 Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: