ML120960375
| ML120960375 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 04/05/2012 |
| From: | Richard Guzman Division of Operating Reactor Licensing |
| To: | Vandeputte D Nine Mile Point |
| Guzman R, NRR/DORL 415-1030 | |
| References | |
| TAC ME6721 | |
| Download: ML120960375 (2) | |
Text
From:
Guzman, Richard Sent:
Thursday, April 05, 2012 12:48 PM To:
'Vandeputte, Dennis E'
Subject:
RE: NMP1 RPV Head Weld Flaw Evaluation - Request for Additional Information
- Dennis, As we discussed, the NRC staff is reviewing the information provided in the NMPNS letter dated June 28, 2011 (ADAMS Accession No. ML11188A194) and has determined that additional information is needed to support its review. Below is the NRC staffs request for additional information. As we discussed today, it was agreed that your response would be provided by May 18, 2012. Please contact me if you have any questions regarding this request.
Issue: Section 6.3.2 includes a fatigue crack growth analysis. The actual applied stress intensity K for the large indication in the RPV head weld is assumed to be less than a stress intensity factor K of 63.25 ksi-in1/2 based on the nominal safety factor with the minimum fracture toughness of the material.
Request: Justify the assumed stress intensity factor K of 63.25 ksi-in1/2 by calculating the maximum applied K for the large indication in the RPV head weld under normal operating conditions. Include a reference for the formula used to calculate the applied K.
Rich Guzman Sr. Project Manager NRR/DORL/LPL1-1 US NRC 301-415-1030 From: Guzman, Richard Sent: Wednesday, March 28, 2012 2:10 PM To: 'Vandeputte, Dennis E'
Subject:
NMP1 RPV Head Weld Flaw Evaluation
- Dennis, See RAI below for subject review. We can discuss via conference call if any clarifications are needed to support your formal RAI response. Next week Wed, Thur, or Friday works for us.
- Thanks, Rich
DRAFT RAI-------------------------------------------------------
The staff has found that additional information is required from the licensee concerning the flaw evaluation for a large indication in the reactor pressure vessel (RPV) head weld at Nine Mile Point Nuclear Station, Unit 1.
Issue: Section 6.3.2 includes a fatigue crack growth analysis. The actual applied stress intensity K for the large indication in the RPV head weld is assumed to be less than a stress intensity factor K of 63.25 ksi-in1/2 based on the nominal safety factor with the minimum fracture toughness of the material.
Request: Justify the assumed stress intensity factor K of 63.25 ksi-in1/2 by calculating the maximum applied K for the large indication in the RPV head weld under normal operating conditions. Include a reference for the formula used to calculate the applied K.
DRAFT RAI-------------------------------------------------------