05000269/LER-2004-001, Re Trip Due to Foreign Material in Turbine Electro-Hydraulic Control System
| ML041260154 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/26/2004 |
| From: | Rosalyn Jones Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 04-001-00 | |
| Download: ML041260154 (9) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 2692004001R00 - NRC Website | |
text
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,SPower, A Duke Energy Company R. A. JONES Vice President Duke Power 29672 1 Oconee Nuclear Site 7800 Rochester Highway Seneca, SC 29672 864 885 3158 864 885 3564 fax April 26, 2004 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555 Subject: Oconee Nuclear Station Docket Nos. 50-269,-270, -287 Licensee Event Report 287/2004-01, Problem Investigation Process No.:
Revision 0 0-04-0991 Gentlemen:
Pursuant to 10 CFR 50.73 Sections (a)(1) and (d), attached is Licensee Event Report 287/2004-01, Revision 0, regarding a reactor trip due to closure of the turbine stop valves as a result of foreign material in the hydraulic control fluid.
This report is being submitted in accordance with 10 CFR 50.73 (a)(2)(iv)(A).
This event is considered to be of no significance with respect to the health and safety of the public.
There are no NRC Commitment items contained in this LER.
Very V
- yours, Attachment
'_t 11, www.duke-energy.com
Document Control Desk Date: April 26, 2004 Page 2 cc:
Mr. Luis A. Reyes Administrator, Region II U.S. Nuclear Regulatory Commission 61 Forsyth Street, S. W., Suite 23T85 Atlanta, GA 30303 Mr.
L. N. Olshan Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C.
20555 Mr. M. C. Shannon NRC Senior Resident Inspector Oconee Nuclear Station INPO (via E-mail)
Abstract
At 11:50:56 on 02-26-2004 Oconee Unit 3 reactor tripped on high Reactor Coolant System pressure approximately three minutes after an Electro-Hydraulic Control (EHC) pump was returned to service following routine maintenance.
Post-trip response was normal.
Investigation found that a small piece of foreign material, specifically a piece of clear plastic packaging material, inadvertently entered the system during replacement of a discharge filter.
The material clogged the hydraulic fluid entry port of a turbine stop valve, causing all four stop valves to close.
The root cause was determined to be inattention to detail by two Maintenance technicians performing the task.
The material was found and removed.
This event is considered to have no significance with respect to the health and safety of the public.
NRC FORM 366 (7-2001)
PRC =
(If more space Is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Fonn 366A) (17)
CAUSAL FACTORS The root cause of this event is lack of attention to detail on the part of the two Nuclear Maintenance Specialists who installed new filters in the EHC system.
When inspecting the filters prior to installation, they did not detect that a piece of shrink wrap remained attached to one filter.
The associated EHC pump was started which transported the piece into the system.
Approximately three minutes later it blocked the flow of hydraulic fluid to MSSV 3MS-104, which caused all four MSSVs to close, resulting in the reactor trip.
The following program weaknesses were identified as contributing
causes
- 1) Management standards and expectations are not well defined in respect to FME. Nuclear Systems Directive 104 "Materiel Condition/Housekeeping, Cleanliness/and Foreign Material Exclusion and Seismic Concerns", the FME controlling document, is part of a broad based directive that includes material condition, housekeeping, and seismic concerns. The directive does not contain:
- "how to" instructions related to cleanliness inspections of new
- parts,
- expectations for the use of auxiliary lighting (e.g. flashlight or work light) for FME prevention
- precautions concerning clear plastic (except in areas of the Spent Fuel Pool and Containment)
- 2) No maintenance procedure exists to provide the level of detail needed at the craft level.
- 3) No maintenance procedure exists for changing the EHC Discharge filter.
Interviews with the technicians on the afternoon after the trip indicated no problems associated with fitness for duty (substance abuse, fatigue, overwork, illness, stress, etc.), time pressure, communications, training, supervision, etc.
Both have been employed at ONS over 20 years.
They have performed this task numerous times in the past but the last occasion was approximately one year ago.
(if more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17) for improvement.
These included establishing a FME steering team to improve the cultural sensitivity to the consequences of FME events among ONS employees.
The trip of the Reactor constitutes a Maintenance Rule functional failure and is considered reportable under the Equipment Performance and Information Exchange (EPIX) program.