05000286/LER-2003-001, From Indian Point Unit 3 Regarding Manual Reactor Trip Due to High Differential Pressure Between Condenser Sections
| ML030760296 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 03/11/2003 |
| From: | Dacimo F Entergy Nuclear Northeast |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-03-043 LER 03-001-00 | |
| Download: ML030760296 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv), System Actuation |
| 2862003001R00 - NRC Website | |
text
E t
~- N-%Enteqgy Entergy Nuclear Northeast Indian Point Energy Center 295 Broadway, Suite 1 PO Box 249 Buchanan, NY 10511-0249 Tel 9147345340 Fax 914 734 5718 Fred Dacimo Vice President, Operations March 11, 2003 NL-03-043 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop 0-P1 -17 Washington, D.C. 20555-0001
SUBJECT:
Indian Point Nuclear Power Plant Unit 3 Docket No. 50-286 License No. DPR-64 Licensee Event Report # 2003-001-00
Dear Sir:
The attached Licensee Event Report (LER) 2003-001 -00 is hereby submitted in accordance with the requirements of 10 CFR 50.73. This event is of the type defined in 10 CFR 50.73(a)(2)(iv) for an event recorded in Entergy's corrective action process as Condition Report CR-IP3-2003-00160.
Entergy is making no new commitments in this LER. Should you have any questions regarding this submittal, please contact Mr. John McCann, Manager of Licensing, Indian Point Energy Center at (914) 734-5074.
Very
- urs, Fred R. Dacimo Vice President, Operations Indian Point Energy Center cc: See next page
Docket No. 50-286 NL-03-043 Page 2 of 2 cc:
Mr. Hubert J. Miller Regional Administrator Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, Pennsylvania 19406-1415 Mr. Patrick D. Milano, Senior Project Manager Project Directorate I Division of Licensing Project Management U.S. Nuclear Regulatory Commission Mail Stop 0-8-C2 Washington, DC 20555 INPO Record Center 700 Galleria Parkway Atlanta, Georgia 30339-5957 U.S. Nuclear Regulatory Commission Resident Inspectors' Office Indian Point 3 Nuclear Power Plant P.O. Box 337 Buchanan, NY 10511-0038
Abstract
On January 13, Operations manually tripped the reactor in accordance with Off Normal Operating Procedure ONOP-C-1 due to high differential pressure (dp) between sections of the main condenser.
The high dp was due to a loss of circulating water in one condenser section as a result of the trip of the 35 circulating water pump (CWP) while the 36 CWP was tagged out of service for planned maintenance. All control rods fully inserted. The plant was stabilized in hot standby with decay heat being removed by the main condenser.
Offsite power remained available and the emergency diesel generators did not start.
The auxiliary feed water (AFW) system automatically started.
The cause of the event was a high dp between condenser sections.
The apparent cause of the 35 CWP trip was a failure of the positive DC exciter lead terminal lug that connects the exciter rotor to the main rotor of the pump motor.
The failure was a result of the lead rubbing against the motor dust cover due to improper cable position during a previous maintenance activity. Corrective actions included troubleshooting and repair of the 35 CWP, testing and repair of the CWP Standby drive, and return to service of the 36 CWP.
A discussion of the event and management expectations on human performance was communicated to the maintenance department and site population. Maintenance procedure MTR-004-CWP was revised to provide a caution regarding motor exciter leads and assembly details. Procedure PMP-052-CWS will be revised to include a requirement to open and inspect CWP motors brought on site from a vendor.
The event had no effect on public health and safety.
(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 (If more space is required, use additional copies of NRC Form 366A) (17)
SAFETY SIGNIFICANCE
This event had no effect on the health and safety of the public.
There were no actual safety consequences for the event because the event was an uncomplicated reactor trip with no other transients or accidents.
Required safety systems performed as designed when the RT occurred.
The AFWS actuation was expected due to steam generator level changes, which occur after a RT from high power levels.
There were no significant potential safety consequences of this event under reasonable and credible alternative conditions.
A loss of a CWP (e.g., 35 CWP)
- -and therefore cooling to a condenser section may result in a loss of condenser vacuum, loss of megawatts, or high turbine exhaust hood temperatures.
Low condenser vacuum will result in a turbine trip.
When the unit load is greater than the Permissive P-8 setpoint, a trip of the turbine generator initiates a RT.
A loss of external electrical load/turbine trip is an analyzed event described in FSAR Chapter 14.
The plant performed as expected and the event was bounded by the FSAR analysis.
The trip of the 32 RCP, after transfer of the 32 RCP's normal 6.9 KV power source from Bus 4 to Bus 6, resulted in loss of forced flow in reactor coolant loop 32.
The loss of forced RC flow caused by the loss of one out of four RCPs from full power is an analyzed event in FSAR Section 14.1.6. Protection from a partial loss of flow event is provided by a RT.
Below the P-7 Permissive, natural circulation flow provides adequate cooling.
Following RT, the affected RCP will continue to coast down and a stable plant condition will be attained.
The plant performed as expected and the 32 RCP trip event was bounded by the FSAR analysis.
For this event rod control was in automatic and the reactor scrammed immediately upon a manual RT.
RCS pressure remained below the set point for pressurizer PORV or code safety valve operation and above the set point for automatic safety injection actuation.
Following the RT, the plant was stabilized in hot standby.