ML083250175
| ML083250175 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/13/2008 |
| From: | Beltz T Plant Licensing Branch III |
| To: | Scarpello M, Waters J American Electric Power Co |
| beltz T, NRR/DORL/LPL3-1, 301-415-3049 | |
| References | |
| Download: ML083250175 (1) | |
Text
From:
Terry Beltz Sent:
Thursday, November 13, 2008 7:40 AM To:
mkscarpello@aep.com; 'jrwaters@aep.com' Cc:
Vijay Goel; Gerald Waig
Subject:
Draft Supplemental RAI re: Amendment for DG Maximum Steady-State Frequency and Voltage Michael and Joe By application dated June 27, 2007 (ADAMS Accession No. ML071910238), Indian Michigan Power Company (I&M) requested changes to the D. C. Cook Nuclear Plant Units 1 and 2, Technical Specifications (TS) Section 3.8.1, relating to the maximum steady state frequency of diesel generators (DGs). In response to the previous staff request for additional information, I&M provided supplemental information on April 28, 2008 (ML081280649) and September 4, 2008 (ML082600469).
In the September 4, 2008, supplemental response, I&M proposed additional changes to TS Section 3.8.1. The NRC Electrical Engineering Branch (EEEB) staff has reviewed the information provided in the supplemental response. Based on the review, additional information is requested regarding the proposed change to the maximum EDG frequency allowed within 2 seconds following rejection of the single largest post-accident load (SR 3.8.1.10.c).
You proposed to change to the maximum EDG frequency allowed within 2 seconds following rejection of the single largest post-accident load in the SR 3.8.1.10.c from 61.2 hertz (Hz) to 60.5 Hz. The Technical Specification Bases for SR 3.8.1.10 states that the specified 2 seconds is equal to approximately 60% of the 3.49 second load sequence interval associated with sequencing of the largest load. According to the updated final safety analysis report (FSAR),
Section 8.4, the largest sequenced load is the Centrifugal Charging Pump (600 hp), which is sequenced at 13 seconds; i.e., 3 seconds after the first block load connection at 10 seconds.
The next load is sequenced at 17 seconds.
Our reviewer, Vijay Goel, has developed the following questions which we would like to discuss with you in a conference call:
- 1. Explain the basis for the 3.49 seconds load sequence interval which is stated in the TS Bases.
- 2. Explain how the specified 2 seconds is equal to approximately 60% of the load sequence interval associated with sequencing of the largest load.
This e-mail aims solely to prepare you and others for the proposed conference call. We can discuss the draft questions and how to disposition them during any subsequent conference call.
This e-mail does not formally convey an NRC staff position, nor does it formally request additional information. With or without the conference call, we plan to issue the formal RAIs to you in the near future and no later than December 12, 2008.
Sincerely, Terry A. Beltz, Senior Project Manager Plant Licensing Branch III-1
Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation (301) 415-3049 Terry.Beltz@nrc.gov cc: Vijay Goel; Gerald Waig E-mail Properties Mail Envelope Properties (BB882299B277DB4C9C9A613B507A6F6003285F5404)
Subject:
Draft Supplemental RAI re: Amendment for DG Maximum Steady-State Frequency and Voltage Sent Date: 11/13/2008 7:39:39 AM Received Date: 11/13/2008 7:39:00 AM From: Terry Beltz Created By: Terry.Beltz@nrc.gov Recipients:
mkscarpello@aep.com (mkscarpello@aep.com)
Tracking Status: None jrwaters@aep.com ('jrwaters@aep.com')
Tracking Status: None Vijay.Goel@nrc.gov (Vijay Goel)
Tracking Status: None Gerald.Waig@nrc.gov (Gerald Waig)
Tracking Status: None Post Office:
HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 15186 11/13/2008 Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: