ML070990628
| ML070990628 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 04/09/2007 |
| From: | Tam P NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | Scarpello M, Simpson S, Vasey R American Electric Power Co, Indiana Michigan Power Co |
| References | |
| TAC MD3737, TAC MD3738 | |
| Download: ML070990628 (3) | |
Text
From:
Peter Tam To:
Bob Vasey; Michael Scarpello; Sue Simpson Date:
4/9/2007 3:39:12 PM
Subject:
D. C. Cook - Draft RAI Questions re. Risk-Informed ISI Program (TAC MD3137, 8)
Bob:
By a previous e-mail (Accession No. ML070890463) I sent you draft RAI questions from the PRA branch. Following are draft RAI questions from our Piping and NDE Branch (Andrea Keim, reviewer). We request that you discuss these two sets of draft RAI questions and your proposed response with us either in a conference call, or in a public meeting:
(1)
Footnote 2 for the table on page 9 of the licensees submittal indicates that 240 Class 2 welds are HSS, yet only 22 welds are selected for inspection at Unit 1 and 228 Class 2 welds are HSS yet only 20 welds are selected for inspection at unit 2. These selections do not appear to meet the 10% requirement for HSS locations. Please explain this discrepancy.
(2)
Section 5 of the licensees submittal states that the licensee will implement the RIS B program during the plants third period of the current (third) inspection interval by performing 66% of the inspection locations selected for examination per the RIS B process for each unit.
Describe how the licensee will determine which examinations to perform during the remainder of the third 10-year ISI interval.
(3)
Please describe how volumetric examinations will be performed. At a minimum, will volumetric examinations include the volume required for ASME Section XI examinations? Will ASME Section XI, Appendix VIII qualified examiners and procedures be used for all volumetric exams? Will the examination volume be scanned for both axial and transverse indications for all exams? Please describe and justify your answers.
(4)
Please describe how preservice examinations will be performed for repair/replacement activities. Include what repair/replacement items will receive preservice examination.
(5)
Page 10 discusses additional examinations. Please describe what will be used to perform the engineering evaluation to determine the cause of any unacceptable flaw or relevant condition. Recent industry practice has been to perform corrective actions (i.e., overlays, replacement, etc.) prior to a root cause being determined (e.g., use of a qualified procedure and personnel).
(a)
In some cases no materials are removed for metallurgical analysis. Please discuss the process used for this engineering evaluation, how will it be documented, and will the Nuclear Regulatory Commission be involved in the process?
(b)
Discuss what process will be used to perform fracture mechanics evaluations (c)
Discuss under what conditions would there be no additional examinations.
Discuss how the licensee will document its justification.
(6)
Page 10, Section 3.3.2 Program Relief Requests, provides guidance. For program relief requests the licensee refers to the process outlined in Reference 2. Recently there have been problems associated with giving relief limited examinations from risk-informed ISI program items. For limited examinations of RIS_B selected items please describe the process for assessing limited examination coverage. Discuss whether additional examinations will be performed, and whether additional techniques will be used to improve examination coverage.
Discuss how the effect on risk of the incomplete examination coverage will be assessed. In what time frame will relief requests be submitted?
(7)
Page 10 also discusses that Relief Requests ISIR-005 and ISIR-006 will be withdrawn.
Please discuss why these requests will be withdrawn. Also the licensee states that pipe-to-flue head welds in the feedwater system are included in the scope that is designated high safety significant, yet have not been selected for examination. Describe why none of these welds are selected for examination.
(8)
Section 3.3.2 states that an attempt was made to select locations for examination such that a minimum >90% coverage is attained. Discuss how this attempt was conducted. If less than 90% examination is completed, discuss whether additional weld(s) will be examined to compensate for the limited examination coverage.
The e-mail aims solely to prepare you and others for a proposed conference call or public meeting. It does not formally convey an NRC staff technical position, and it does not formally request for additional information.
Peter S. Tam, Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation e-mail: pst@nrc.gov Tel.: 301-415-1451 CC:
Andrea Keim; Bhalchandra Vaidya; Stephen Dinsmore Mail Envelope Properties (461A9660.A95 : 12 : 35330)
Subject:
D. C. Cook - Draft RAI Questions re. Risk-Informed ISI Program (TAC MD3137, 8)
Creation Date 4/9/2007 3:39:12 PM From:
Peter Tam Created By:
PST@nrc.gov Recipients Action Date & Time aep.com Transferred 4/9/2007 3:39:44 PM mkscarpello (Michael Scarpello) rgvasey (Bob Vasey) sdsimpson (Sue Simpson) nrc.gov OWGWPO03.HQGWDO01 Delivered 4/9/2007 3:39:19 PM SCD1 CC (Stephen Dinsmore)
Opened 4/9/2007 3:52:31 PM nrc.gov OWGWPO04.HQGWDO01 Delivered 4/9/2007 3:39:18 PM ATK CC (Andrea Keim)
Opened 4/9/2007 3:39:29 PM nrc.gov TWGWPO04.HQGWDO01 Delivered 4/9/2007 3:39:19 PM BKV CC (Bhalchandra Vaidya)
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