ML102040293
| ML102040293 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 07/21/2010 |
| From: | Mahesh Chawla Plant Licensing Branch III |
| To: | Hassoun A Detroit Edison |
| chawla M, ADRO/DORL, 415-8371 | |
| References | |
| TAC ME3011 | |
| Download: ML102040293 (2) | |
Text
From:
Chawla, Mahesh Sent:
Wednesday, July 21, 2010 5:19 PM To:
Alan I Hassoun Cc:
Ward, Leonard; Matharu, Gurcharan; Matharu, Gurcharan; McConnell, Matthew; Pascarelli, Robert; Lingam, Siva; Feintuch, Karl
Subject:
Fermi 2 - ME3011 - LAR to revise CS Flow Requirement of TS Surveillance Tests SR 3.5.1.8 and SR 3.5.2.6 - Request for Additional Information By letter to the U.S. Nuclear Regulatory Commission (NRC) dated January 4th 2010, Detroit Edison requested an amendment to the Fermi Operating License. The licensee proposed to modify Technical Specifications Surveillance Requirements 3.5.1.8 and 3.5.2.6 related to Core Spray flow requirements. The intent is to reduce the flow requirement from 6350gpm to 5725gpm. The staff reviewed the ECCS analyses pertinent to the FERMI-2 reanalysis.
The following Request for Information (RAI) is listed below based on this review. Please arrange a teleconference to discuss this information with the NRC staff:
1.0 The Core Spray (CS) pump surveillance requirement is being reduced from 6350 gpm to the ECCS analysis assumption of 5725 gpm per division (2 pumps) corresponding to a reactor pressure of 100 psig. Please confirm that this surveillance flow requirement accounts for the maximum error on RCS pressure and flow. That is, please show that the maximum error on pressure and flow was assumed in developing the head flow curve for the CS pumps assumed in the ECCS analyses. Please identify the error on pressure and flow and show the head vs flow curve for the CS pumps assumed in the ECCS analyses.
2.0 Please explain why smaller Appendix K breaks in the range 0.1 to 0.05 ft2 do not cause higher PCTs since the smaller breaks would delay LPCS and produce a longer period of core uncover and heat-up that could potentially produce a more limiting break. Were breaks in the range 0.2 to 0.05 evaluated. Please explain.
3.0 Please identify the limiting axial power shape for the limiting Appendix K SBLOCA and verify that top peaked axial power profiles were evaluated for the limiting SBLOCA.
4.0 Please confirm that the limiting SBLOCA hot rod heat-up analysis showed cooling from bottom up re-flood and that top down ECCS core spray injection did not terminate the clad heat-up for the hot rod.
5.0 Please confirm that the 10 minute operator action time for manual depressurization is an integral part of the EOP training for ECCS events. Please also confirm that the level and pressure indication for alerting the operators to the need for a manual depressurization includes the appropriate LOCA environmental error on these two instrument responses when assuming credit for this action in the ECCS analyses.
6.0 The licensee states in section 4 of the amendment request that the analysis to demonstrate the adequacy of 5725 gpm took into account instrument uncertainty and emergency diesel
generator (EDG) under-frequency. This implies that the potential operation of the EDG at the lowest allowable frequency will result in adequate flow to satisfy Appendix K safety analyses. The loading impact on the EDG has not been discussed.
The EDG allowable frequency range per TS SR 3.8.1.2 is 2.0% of 60Hz. The allowable voltage range is 3873V and 4580V. Describe the consequences on EDG loading if the EDG operates at the extremes of the voltage and frequency range during emergency operation.
E-mail Properties Mail Envelope Properties ()
Subject:
Fermi 2 - ME3011 - LAR to revise CS Flow Requirement of TS Surveillance Tests SR 3.5.1.8 and SR 3.5.2.6 - Request for Additional Information Sent Date: 7/21/2010 5:04:03 PM Received Date: 7/21/2010 5:18:00 PM From: Chawla, Mahesh Created By: Mahesh.Chawla@nrc.gov Recipients:
hassouna@dteenergy.com (Alan I Hassoun)
Tracking Status: None Leonard.Ward@nrc.gov (Ward, Leonard)
Tracking Status: None Gurcharan.Matharu@nrc.gov (Matharu, Gurcharan)
Tracking Status: None Gurcharan.Matharu@nrc.gov (Matharu, Gurcharan)
Tracking Status: None Matthew.McConnell@nrc.gov (McConnell, Matthew)
Tracking Status: None Robert.Pascarelli@nrc.gov (Pascarelli, Robert)
Tracking Status: None Siva.Lingam@nrc.gov (Lingam, Siva)
Tracking Status: None Karl.Feintuch@nrc.gov (Feintuch, Karl)
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 17543 7/21/2010
Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: