05000454/LER-2004-001, Re Reactor Containment Fan Coolers Flow Rates Below Technical Specification Requirements Due to Inaccurate Flow Indication
| ML052270303 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 08/09/2005 |
| From: | Kuczynski S Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BYRON 2005-0094 LER 04-001-00 | |
| Download: ML052270303 (2) | |
| Event date: | |
|---|---|
| Report date: | |
| 4542004001R00 - NRC Website | |
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BYRON 2005-0094 File:
1.10.0101 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Unit 1 Facility Operating License No. NPF-37 NRC Docket No. STN 50-454
Subject:
Second Revision to Expected Supplemental Report Submittal Date for Licensee Event Report (LER) 454-2004-001-00, Reactor Containment Fan Coolers Flow Rates Below Technical Specification Requirements Due to Inaccurate Flow Indication
References:
- 1. Stephen E. Kuczynski to NRC Document Control Desk, Licensee Event Report (LER) 454-2004-001-00, Reactor Containment Fan Coolers Flow Rates Below Technical Specification Requirements Due to Inaccurate Flow Indication, dated October 17, 2005
- 2. Stephen E. Kuczynski to NRC Document Control Desk, Revision to Expected Supplemental Report Date for Licensee Event Report (LER) 454-2004-001-00, Reactor Containment Fan Coolers Flow Rates Below Technical Specification Requirements Due to Inaccurate Flow Indication, dated April 29, 2005 In reference 2 above, we indicated we expected to submit a supplemental report to the LER (i.e.,
reference 1) in the July 2005 timeframe pending further investigation into the root cause of the inaccurate Unit 1 flow indication for the Reactor Containment Fan Coolers (RCFC5). As of this letter date, the root cause evaluation is still ongoing.
Cleaning and flushing of the instrumentation did not improve the inaccuracies of the flow measurements and consequently, instrument fouling was ruled out as a root cause.
The evaluation is now focused on a possible design application error. Alternate flow measurements of the RCFCs will continue until a root cause is determined and corrective actions taken. We now expect to submit the supplemental report in early 2006.
BYRON 2005-0094 Page 2 August 9, 2005 If you have any questions regarding this matter, please contact William Grundmann, Regulatory Assurance Manager, at (815) 406-2800.
Respectfully,
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Stephen E. Kuczynski Site Vice President Byron Nuclear Generating Station S ED\\J L\\rah