05000318/LER-2003-002, Re Unintentional Reactor Protective System Actuation During Plant Heatup
| ML031760178 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/18/2003 |
| From: | Nietmann K Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 03-002-00 | |
| Download: ML031760178 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 3182003002R00 - NRC Website | |
text
Kevin J. Nietmann Plant General Manager Calvert Cliffs Nuclear Power Plant Constellation Generation Group, LLC 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410 495-4101 410 495-4787 Fax Constellation Energy Group June 18, 2003 U.S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
SUBJECT:
Document Control Desk Calvert Cliffs Nuclear Power Plant Unit No. 2; Docket No. 50-318; License No. DPR 69 Licensee Event Report 318/2003-002 Unintentional Reactor Protective System Actuation During Plant Heatup The attached report is being sent to you as required under 10 CFR 50.73 guidelines. Should you have questions regarding this report, we will be pleased to discuss them with you.
Very truly yours 7
for Kevin J. Nietmann Plant General Manager KJN/MJY/bjd Attachment cc:
J. Petro, Esquire J. E. Silberg, Esquire Director, Project Directorate I-1, NRC G. S. Vissing, NRC H. J. Miller, NRC Resident Inspector, NRC R. I. McLean, DNR 23
Abstract
On April 19, 2003, at approximately 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br />, the Calvert Cliffs Nuclear Power Plant Unit 2 Reactor Trip Circuit Breakers opened automatically on a trip signal from the Reactor Protective System. The trip signal was caused by a steam generator (SG) low pressure trip input. Unit 2 was shutdown with a plant heatup under way. Although Unit 2 Reactor Trip Circuit Breakers were closed to support surveillance testing, control element drive motors were de-energized, and control element assemblies were fully inserted into the core.
The actuation of the reactor trip protective function occurred during plant heatup when the low SG pressure trip bypass signal cleared at approximately 749.8 psia and the low SG pressure trip, which had not reset from the original shutdown, completed the logic circuits to initiate a reactor trip.
Investigation revealed that both the low SG pressure trip and bypass functions were within allowable setpoints. The low SG pressure trip circuitry has a non-adjustable reset function that clears the trip signal approximately 25 - 40 psig above the trip setpoint. This reset function Is a characteristic of each low SG pressure trip circuit card and is not a calibrated value. The combined setpoint and reset function overlap represented no failure of any specific component but identified an off-normal situation that will be procedurally avoided in the future.
NRC FORM 366 (72001)
- 17. NARRATIVE (if more space is required, use additional copies of (ff more space Is required, use additional copies of (f more space Is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A)
C.
Component Identification Component IEEE 803 EIIS Function Reactor Trip Circuit Breaker (AC Circuit Breaker)
.(1-200)
LICENSEE EVENT REPORT (LER)
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE SEQUENTIAL I REVISION IIYEAR I
NUMBER I NUMBER CALVERT CLIFFS, UNIT 2 05000 318 2003 002 00 05 F
005 IEEE 805 System ID 52