05000445/LER-2002-003-01, Regarding Auto Start of the CPSES Unit 1 Train B Emergency Diesel Generator
| ML030230458 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/16/2003 |
| From: | Walker R TXU Energy |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CPSES-200204093, TXX-03004 LER 02-003-01 | |
| Download: ML030230458 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4452002003R01 - NRC Website | |
text
,d TXU TXU Energy Comanche Peak Steam Electric Station PO Box 1002 (EO1)
Glen Rose,TX 76043 Tel. 254 897 8920 Fax 254 897 6652 lance terry@txu corn C. Lance Terry Senior Vice President &
Principal Nuclear Officer Ref: IOCFR50.73(a)(2)(iv)
CPSES-200204093 Log # TXX-03004 January 16, 2003 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NO. 50-445 ACTUATION OF SPECIFIED SYSTEM:
EMERGENCY DIESEL GENERATOR LICENSEE EVENT REPORT 445/02-003-01 Gentlemen:
Enclosed is Supplement 1 to Licensee Event Report (LER) 02-003-00 for Comanche Peak Steam Electric Station Unit 1, "Auto start of the CPSES Unit 1 train B emergency diesel generator."
This communication contains no new licensing basis commitments regarding CPSES Units 1 and 2.
4tS;L
-*, TXU TXX-03004 Page 2 of 2 Sincerely, TXU Generation Company LP By:
TXU Generation Management Company LLC, Its General Partner C. L. Terry Senior Vice President and Principal Nuclear Officer By:i
^,$
/
R er D. Walker Regulatory Affairs Manager GLM/gm Enclosure c -
E. W. Merschoff, Region IV W. D. Johnson, Region IV D. H. Jaffe, NRR Resident Inspectors, CPSES
Enclosure to TXX-03004 NRCJ)ORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB NO 3150-0104 (7-2001)
EXPIRES 07/3112004 the NRC may not conduct or issponsor and a peon i not required to respond to, the tnfornnation collection Facility Name (I)
Docket Nuaier (2)
Page (3)
COMANCHE PEAK STEAM ELECTRIC STATION UNIT 1 05000445 1 OF 5 Title (4)
AUTO START OF THE CPSES UNIT 1 TRAIN B EMERGENCY DIESEL GENERATOR Event Date (5)
LER Number (6)
Rlport Date (7)
Other Facilities Involved (8)
Month Day Year Yer Sequentia l Revisio Month Day Year Facnlty Name Docket Numbers
- - Naster aNue N/A 05000 10 07 02 02 H 003 01 01 16 03 05000 operating Thisr ubrismsulntedprsuant to herequ mentso1of104FR:(Checkallithatapplv) 0 (1)
Mdode (9) 20.2201(b) 20.2203(a)(3)(1) 50 73(a)(2)(X)(C) l l50.73(a)(2)(vit)
Power 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(n)(A) 50.73(a)(2)(viti)(A) 0
_ 20.2203(a)(1) 20 2203(a)(4) 50.73(a)(2)(il)(B) 50.73(a)(2)(Vili)(B) 20.2203(a)(2)(i) 50 36(c)(2)(i)(A) 50.73(a)(2)(ill) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(h) 50 36(c)(I)(ii)(A)
X 50.73(a)(2)(iv)(A) 50.72(a)(2)(x) 20.2203(a)(2)(in) 50 36(c)(2) 50 73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50 73(a)(2)(v)(B) 73.71 (a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50 73(a)(2)(v)(C)
OTHER 20 2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50 73(a)(2)(v)(D)
Specify in Abstract below or
_in (If more space is required, use additional copies of SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES On October 07, 2002, at 0936, during 345 KV switchyard east bus relay testing, an unexpected pickup of a relay contact occurred which generated a signal that caused the Unit 1 6.9 KV safeguards busses to transfer to the alternate power source. The Unit 1 train B emergency diesel generator (EIIS:(DG)) 1-02 unexpectedly auto started while, as designed, the bus re-energized to station transformer XST1. Bus load shedding initiated by bus undervoltage caused both Spent Fuel Pool pumps and the operating Residual Heat Removal pump to trip.
The blackout sequencer (BOS) actuated and functioned as designed. The fuel assemblies in transit were secured in safe locations and core alterations were stopped. The plant operators responded to the loss of normal power to the train B bus and restored equipment shed from the busses by the momentary undervoltage condition.
Residual Heat Removal (RHR) shutdown cooling was restored on the train B RHR pump at 0944 and Spent Fuel Pool cooling restored at 0946. The batteries normally providing backup DC power to the normal (non-safeguards) breaker controls were undergoing replacement at the time, complicating recovery of the non-safeguards busses. Normal plant power was restored at 1112 and core off-load resumed at 1319.
(If more spare equd use additional copies of (If iore space a requied use additional copies of (If imre space is requred. use additonal copies of NRC Form 366A) (17)
V.
CORRECTIVE ACTIONS
The time delay relay 27-2X/1EA2 was replaced with a new relay. The new relay was recalibrated and is within design specifications. Additional relays in associated loss of power emergency diesel generator start circuits were checked and found to be functioning within design requirements.
In addition to the above, as a part of the CPSES Corrective Action Program, Engineering is evaluating possible causes for similar relays to exceed their expected response time during surveillance testing. The scope of the ongoing evaluations also include reassessing the manufacturer's recommendations for these relays, and determining any preventive maintenance, or planned replacement of aged relays as may be appropriate.
VI.
PREVIOUS SIMILAR EVENTS
There have been other events involving the start of an emergency diesel generator. However, details/causes are sufficiently different from the event described in this LER such that the previous corrective actions could not have prevented this event. There have also been previous failures of Agastat relays, but none involving an auto start of an emergency diesel generator.