ML052840272
| ML052840272 | |
| Person / Time | |
|---|---|
| Site: | Mcguire |
| Issue date: | 10/11/2005 |
| From: | Ernstes M NRC/RGN-II/DRP/RPB1 |
| To: | Duke Energy Corp |
| ERNSTES M | |
| References | |
| MR 2-2005-0012 | |
| Download: ML052840272 (1) | |
Text
Morning Report Date: OCT 11, 2005 PRIORITY ATTENTION REQUIRED MORNING REPORT - REGION II Licensee/Facility:
Notification:
2-2005-0012 10/08/2005 MR Number:
DUKE ENERGY CORP.
[2] W-4-LP Date:
Mcguire Call from Licensee Cornelius, North Carolina 050-00370 Dockets:
MCGUIRE NOED FOR INOPERABLE CONTROL ROOM VENTILATION SYSTEM
Subject:
On October 8, 2005, Region II granted a Notice of Enforcement Discretion (NOED) for McGuire Nuclear Station Unit 2, to allow a 24-hour extension of the allowed time for both trains of Control Room Area Ventilation System to be inoperable. As background, Unit 1 was in Mode 6 in a refueling outage and Unit 2 was in Mode 1 at 100% power.
There are two trains of control room ventilation. One train's power supply was aligned to the shutdown unit for Engineered Safety Features (ESF) testing, and therefore technically inoperable. When the control room ventilation chiller for the other train, whose power supply was aligned to operating unit was started, it tripped due to a failed oil pressure switch. This made both trains of Control Room Area Ventilation for Unit 2 inoperable. The licensee immediately entered TS LCO 3.0.3. Since it would take approximately three hours to realign the train on the shutdown unit to the operating unit, the licensee did not want the control room to be without ventilation for that amount of time due to overheating concerns. They requested a 24-hour extension of the allowed outage time. This time would allow the licensee to prepare a temporary modification to bypass the failed oil pressure switch, implement the modification, and conduct post modification testing. This oil pressure switch is only for equipment protection and is not required by TS.
There was a valid oil pressure indication which was being monitored by a dedicated operator as a compensatory measure.
The basis for the NOED was to avoid a Unit 2 shutdown and any unnecessary transients as a result of the shutdown.
All necessary safety systems for Unit 2 were available if called upon. Additionally, continued operation of Unit 2 caused no net increase in radiological risk to the public.
Discussion:
Contact:
Email:
Phone No:
Org:
ERNSTES, MICHAEL E MEE@nrc.gov (404) 562-4540 R2