05000336/LER-2006-004, Re Failure to Enter the Technical Specification Action Statement for Inoperable Reactor Protection System Trips
| ML061710512 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/09/2006 |
| From: | Price J Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 06-477 LER 06-004-00 | |
| Download: ML061710512 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3362006004R00 - NRC Website | |
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Dominion Dominion Nuclear Connecticut, Inc.
Millstone Power Station Rope Ferry Road Waterford, CT 06385 JUN 9 00 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Serial No.
MPS Lic/GJC Docket No.
License No.06-477 RO 50-336 DPR-65 DOMINION NUCLEAR CONNECTICUT. INC.
MILLSTONE POWER STATION UNIT 2 LICENSEE EVENT REPORT 2006-004-00.,
FAILURE TO ENTER THE TECHNICAL SPECIFICATION ACTION STATEMENT FOR INOPERABLE REACTOR PROTECTION SYSTEM TRIPS This letter forwards Licensee Event Report (LER) 2006-004-00, documenting a historical incident that was determined to be reportable at Millstone Power Station Unit 2, on April 13, 2006. This LER is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B),
as operation in a condition prohibited by the Technical Specifications.
If you have any questions or require additional information, please contact Mr. David W.
Dodson at (860) 447-1791, extension 2346.
Very truly yours, An
- - Price aieicpe LPresident - Millstone 9>-
Serial No.06-477 Licensee Event Report 2006-004-00 Page 2 of 2 Attachments:
1 Commitments made in this letter: None.
cc:
U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 Mr. V. Nerses Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 8C2 Rockville, MD 20852-2738 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station
Attachment I Licensee Event Report 2006-004-00, Failure to Enter the Technical Specification Action Statement for Inoperable Reactor Protection Svstem Trios Millstone Power Station Unit 2 Dominion Nuclear Connecticut, Inc. (DNC)
Abstract
During the course of an NRC inspection activity, a concern was raised regarding compliance with Technical Specification Limiting Condition for Operation (TS LCO) 3.3.1.1, which requires that, "as a minimum, the reactor protective (RPS) instrumentation channels and bypasses of table 3.3-1 shall be OPERABLE." Historically, Wide Range Nuclear Instrumentation (WRNI) channels were removed from service at power without declaring the associated channel of Thermal Margin/Low Power (TM/LP), Reactor Coolant System (RCS) Low - Flow, and Reactor Power Level - High inoperable. With the WRNI input inoperable, the associated automatic bypass reset function for the affected channel is also inoperable.
It was identified that this condition occurred multiple times over the last three years, and for a duration that exceeded the allowed outage time and shutdown time of the associated TSAS.
On this basis the condition is reportable pursuant to 10 CFR 50.73(a)(2)(i)(B), as operation in a condition prohibited by the Technical Specifications.
The cause was determined to be a weakness in licensed operator knowledge of the relationship between the WRNIs and the RPS Automatic Bypass Removal functions.
There were no safety consequences associated with this event.
NRC FORM 366 (6-2004)
(If more space is required, use additional copies of (If more space Is required, use additional copies of NRC Form 366A) (17)
- 4.
Assessment of Safety Consequences
In order to bypass the TM/LP, RCS Low Flow, and Reactor Power Level - High reactor trips, the reactor must be
< 5% reactor thermal power and the Zero Mode Bypass Switch must be in the bypass position. During the calibration of the WRNIs the Zero Mode Bypass Switch is in the normal (off) position, therefore, the TM/LP, RCS Low Flow, and Reactor Power Level - High reactor trips were always available. Accordingly, there are no safety consequences associated with this event.
- 5.
Corrective Action
The actions to prevent recurrence include training the Operators on this incident, revision of appropriate station procedures to address this incident, and evaluating the need for a TS change.
Additionally a Night Order has been issued instructing the operators to declare the TM/LP, RCS Low Flow, and Reactor Power Level - High reactor trips inoperable for the affected channel and enter TSAS 3.3.1.1. Action 2, when the associated WRNls are inoperable.
Additional corrective actions are being taken in accordance with the station's corrective action program.
- 6.
Previous Occurrences
No previous similar events/conditions were identified.
Energy Industry Identification System (EIIS) codes are identified in the text as [XX].