05000287/LER-2008-001, Trip Due to Control Rod Drive System Processor Failure
| ML090120436 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 01/07/2009 |
| From: | Baxter D Duke Energy Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 08-001-00 | |
| Download: ML090120436 (9) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2872008001R00 - NRC Website | |
text
Duke DAVE BAXTER Vice President Oconee Nuclear Station Duke Energy Corporation ONO1 VP17800 Rochester Highway Seneca, SC 29672 864-885-4460 864-885-4208 fax January 7, 2009 dabaxter@dukeenergy.com U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555
Subject:
Oconee Nuclear Station Docket No.
50-287 Licensee Event Report 287/2008-01, Revision 0 Problem Investigation Process No.: 0-08-7110 Gentlemen:
Pursuant to 10 CFR 50.73 Sections (a)(1) and (d),
attached is Licensee Event Report 287/2008-01, Revision 0, regarding a reactor trip on Unit 3 which occurred on November 7, 2008.
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 regulatory commitments contained in this report.
Any questions regarding the content of this report should be directed to Russ Oakley at 864-885-3829.
Very truly
- yours, Dave Baxter, Vice President Oconee Nuclear Site Attachment www.duke-energy.comr
Document Control Desk Date: January 7, 2009 Page 2 cc:
Mr. Luis Reyes Administrator, Region II U.S. Nuclear Regulatory Commission 61 Forsyth Street, S.
W.,
Suite 23T85 Atlanta, GA 30303 Mr. John Stang Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C.
20555 Mr. Andy Hutto NRC Senior Resident Inspector Oconee Nuclear Station INPO (Word File via E-mail)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Oconee Nuclear Station, Unit 3 05000287 1 OF 7
- 4. TITLE Unit 3 Trio Due to Control Rod Drive System Processor Failure
- 5. EVENT D E
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YERSEQUENTIAL REV MOT DA ERFACILITY NAME DOCKET NUMBER NUMBER NO.
05000 FACILITY NAME DOCKET NUMBER 11 07 2008 2008 01 0
01 07 2009 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
E] 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
[] 20.2201(d)
El 20.2203(a)(3)(ii)
[I 50.73(a)(2)(ii)(A)
[] 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
[E 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A)
[] 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2)
[I 50.73(a)(2)(v)(A)
El 73.71 (a)(4)
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
[I 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100%
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
[] OTHER El 20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form ý366A)
- Unit 3 cable room receiver sent this signal to the Truetime SF DC clock in the Sequence of Events Recorder (SER) cabinet, as designed.
0 Zero date stamp output was sent from Unit 3 clock to CRD Primary Processors P1 and P2.
The zero date value was not an expected output.
" Unable to decode the zero date stamp, the Unit 3 CRD Primary Processors P1 and P2 completely stopped.
This was not an expected response.
- Without P1 and P2 operating, the CRD system input/output (I/O) modules went to fail safe state (i.e.,
off or zero) as designed.
- The single rod power supplies (SRPS) turned OFF because they were no longer getting a command signal to energize any phases (expected response).
At this time, the control rods dropped into the core.
This was also an expected response.
" Relays which are normally energized de-energized.
This produced a Reactor Trip Confirm (RTC) signal.
This was an expected response.
" The RTC signal initiated a turbine trip and generator [TB]
lockout.
This was an expected response.
0 RPS received a Loss of Main Turbine Anticipatory Trip signal and tripped the CRD Breakers, as designed.
All control rod drop
ýtimes were within expected limits.
Post-Trip Response No safety system actuations occurred other than the RPS.
On the primary side, Reactor Coolant Pumps [AB] [P] continued to operate and provide core cooling.
RCS pressure, temperature, flow, and inventory remained within expected post-trip limits.
Secondary side response was normal.
Main Steam Relief Valves (MSRVs) lifted and reseated as expected.
Secondary systems remained in service and provided heat removal capability, and shutdown to Mode 4 was not necessary.
The Unit was maintained in Mode 3 while post-trip reviews were completed, the cause of the event was identified, and it was determined to be safe to return the unit to service.
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ADDITIONAL INFORMATION
A search of Oconee's corrective action database found no similar occurrences of this type of event with same cause.
There were no releases of radioactive materials, radiation exposures or personnel injuries associated with this event.
This event is not considered reportable under the Equipment Performance and Information Exchange (EPIX) program.
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