05000416/LER-2005-003, Regarding Mode Change Contrary to Technical Specification LCO 3.0.4
| ML053540031 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 12/19/2005 |
| From: | Bottemiller C Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GNRO-2005/00072 LER 05-003-00 | |
| Download: ML053540031 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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 |
| 4162005003R00 - NRC Website | |
text
GNRO-2005/00072 December 19, 2005 U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention :
Document Control Desk Subject :
LER 2005-003 Mode Change Contrary To Technical Specification LCO 3.0.4 Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29
Dear Sir or Madam:
Attached is Licensee Event Report (LER) 2005-003-00 which is a final report.
This letter does not contain any commitments.
Yours truly, CAB/WBA Attachment :
LER 2005-003-00 cc:
(See Next Page)
S3050
GNRO-2005/00072 Page 2 cc :
NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 U. S. Nuclear Regulatory Commission ATTN : Dr. Bruce S. Mallet (w/2)
Regional Administrator, Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 U. S. Nuclear Regulatory Commission ATTN : Mr. Bhalchandra Vaidya, NRR/DORL (w/2)
ATTN : ADDRESSEE ONLY ATTN : U. S. Postal Delivery Address Only Mail Stop OWFN/7D-1 Washington, DC 20555-0001 Mr. D. E. Levanway (Wise Carter)
Mr. L. J. Smith (Wise Carter)
Mr. N. S. Reynolds Mr. J. N. Compton
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO
. 3150-0104 EXPIRES: 06/30/2007 POW)
, the NRC may digitstcharacters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
1. FACILITY NAME Z DOCKET NUMBER PAGE Grand Gulf Nuclear Station, Unit 1 05000 416 T 1 OF 4
- 4. TITLE LER 2005-003 Mode change contrary to Technical Specification LCO 3.0.4 5. EVENT DATE I LER NUMBER 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR N/A N/A FACILITY NAME DOCKET NUMBER 10 7
2005 2005 - 003 - 00 12 19 2005 N/A N/A
- 9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§ : (Check all that app/4y)
[3 212201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii) 2 0 20.2201(d)
F1 20.2203(a)(3)(ii) n 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A) 01 20.2203(a)(1)
El 20.2203(a)(4) 10] 50.73(a)(2)(ii)(B)
[:1 50.73(a)(2)(viii)(B)
[:1 20.2203(a)(2)(i)
F1 50.36(c)(1)(i)(A) n 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A) 10. POWER LEVEL n 20.2203(a)(2)(ii) n 50.36(c)(1)(ii)(A)
[:] 50.73(a)(2)(iv)(A)
[:1 50.73(a)(2)(x)
[I 20.2203(a)(2)(iii) n 50.36(c)(2)
Fj 50.73(a)(2)(v)(A)
F] 73.71(x)(4)
Fl 20.2203(a)(2)(iv)
Fl 50.46(a)(3)(ii)
[I 50.73(a)(2)(v)(B) 0 73.71(a)(5) 0 El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
E] 50.73(a)(2)(v)(C) n OTHER [I 20.2203(a)(2)(vi) 10 50.73(a)(2)(i)(B)
Ej 50.73(a)(2)(v)(D)
Specify in Abstract below or in NRC Form 366A 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (include Area Code)
Grand Gulf Nuclear Station - William B. Abraham, Senior Engineer Associate 601-437-2319 13. COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT MANU-REPORTABLE MANU-REPORTABLE FATWRER TO ERX
~FACTURER TO EPIX EM =~ EMMM 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED SUBMISSION El YES (Ifyies, complete 15. EXPECTED SUBMISSION DATE)
Z NO DATE 1-ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
NRC FORM 366 (6-2W4)
The Division I Load Shed and Sequencer power supply was replaced on October 7, 2005 as part of routine preventative maintenance. During a Technical Specification (TS) Surveillance performed on October 25, the as found voltages for the Division I Engineered Safety Features Degraded Voltage set points were found to be higher than the TS Allowable Values. This condition was immediately corrected ; however, since the cause of the setpoints being outside the allowed values occurred during the power supply replacement on October 7, the setpoints had been out of the allowable values from October 7 until October 25. TS require that the setpoints be brought to within allowable values within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or declare the associated emergency diesel generator (EDG) inoperable (which prohibits changing plant operational modes). Since the impact of the power supply replacement on the Bus Under Voltage bistable setpoints was not recognized and the appropriate TS action statement was not entered, the station violated TS 3.0.4 when the plant was brought into Mode 2 on October 16 and again on October 18 When the plant was brought into Model.
This condition was determined to be reportable in accordance with 1 0CFR5l173(a)(2)(0(B) since the plant was in an Operation or Condition prohibited by TS 3.0.4. There was no loss of safety function since it was limited to a single division and was a deviation in a setpoint. Re system would have actuated somewhat earlier on a low voltage transient but would have functioned properly otherwise. (1-2001)
LICENSEE EVENT REPORT (LER)
U.S. NUCLEAR REGULATORY COMMISSION 1. FACILITY NAME 1
2. DOCKET-(-
6. LER NUMBER 1
3. PAGE Grand Gulf Nuclear Station, Unit 1 105000416 YEAR SEQUENTIAL NUMBER REVISION NUMBER 2005
-- 003 --
00 1
2 OF A. REPORTABLE OCCURRENCE The Division I Load Shed and Sequencer (LSS) power supply was replaced on October 7, 2005 as part of routine preventative maintenance during a Refueling Outage. During a Technical Specification Surveillance performed on October 25, the as found voltages for the Division I Engineered Safety Features (ESF) Degraded Voltage set points were found to be higher than the Technical Specification Allowable Values. This condition was immediately corrected ; however, since the cause of the setpoints being outside the allowed values occurred during the power supply replacement on October 7, the setpoints had been out of the allowable values from October 7 until October 25. Technical Specifications require that the setpoints be brought to within allowable values within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or declare the associated emergency diesel generator (EDG) [DG]
inoperable (which prohibits changing plant operational modes). Since the impact of the power supply replacement on the Bus Under Voltage (BUV) bistable setpoints was not recognized and the appropriate Technical Specification action statement was not entered, the station violated Technical Specifications 3.0.4 when the plant was brought into Mode 2 on October 16 and again on October 18 when the plant was brought into Mode 1.
This condition was determined to be reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) since the plant was in an Operation or Condition prohibited by Technical Specification Limiting Condition for Operation (LCO) 3.0.4. There was no loss of safety function since it was limited to a single division and was a deviation in a setpoint. The system would have actuated somewhat earlier on a low voltage transient but would have functioned properly otherwise.
B.
INITIAL CONDITIONS At the time of the event, the reactor was in OPERATIONAL MODE 2 (STARTUP), at zero percent power.
C.
DESCRIPTION OF OCCURRENCE The Division I Load Shed and Sequencer power supply was replaced on October 7, 2005 as part of routine preventative maintenance in a Refueling Outage. This power supply provides the reference voltage for the Division 1 ESF Degraded Voltage bistable setpoints. A functional test of the power supply output was performed per the retest matrix contained in Administrative Procedure, 01-S-07-2 (Test Control), Revision 104.
During a Technical Specification Surveillance performed on October 25, the as found voltages for the Division I ESF Degraded Voltage set points were found to be higher than the Technical Specification Allowable Values. (The Load Shed and Sequencer uses a series of BUV bistables with a setpoint of 90 percent BUV and a series of BUV bistables with a setpoint of 70 percent BUV.
LER 2005-003-00
Only the 90 percent bistables were found out of Technical Specification Allowable Values. The 70 percent bistables were within Technical Specification Allowable.) This condition was immediately corrected ; however, since the cause of the setpoints being outside the allowed values occurred during the power supply replacement on October 7, the setpoints had been out of the allowable values from October 7 until October 25.
Technical Specifications require that the setpoints be brought to within allowable values within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or declare the associated EDG inoperable (which prohibits changing plant operational modes). Since the impact of the power supply replacement on the BUV bistable setpoints was not recognized and the appropriate Technical Specification action statement was not entered, the station violated Technical Specification NCO 3.0.4 when the plant was brought into Mode 2 on October 16 and again on October 18 when the plant was brought into Mode 1.
D.
APPARENT CAUSE The cause has been determined to be a failure to recognize that a BLIV bistable setpoint check was needed following the replacement of the power supplies within the LSS panel. Although the power supplies were within the manufacturer's specified voltage range, a difference in output voltage from the previously installed power supply altered the reference voltage utilized by the LSS logic, thus altering the setpoints to some degree.
E.
CORRECTIVE ACTIONS
Immediate Corrective Actions :
Bistable setpoints were adjusted within Technical Specification limits per Surveillance Work Order.
Long Term Corrective Actions :
0 Condition Report (CR)-GGN-2005-04665 was initiated.
SAFETY ASSESSMENT
There was no loss of safety function since it was limited to a single division and was only a deviation in a setpoint. The system would have actuated somewhat earlier on a low voltage transient but would have functioned properly otherwise.
Therefore, there were no adverse safety consequences or implications as a result of the condition and the condition (Ad not adversely affect the safe operation of the plant or health and safety of the public.
LER 2005-003-00 U.S. NUCLEAR REGULATORY COMMISSION (1-2001)
LICENSEE EVENT REPORT (LER) 1. FACILITY NAME 2. DOCKET 6. LER NUMBER
- 3. PAGE SISEQUENTIAL I REVISION YEAR NUMBER NUMBER l Grand Gulf Nuclear Station, Unit 1 05000416 2005
-- 003 --
00 3
OF 4 (11MI)
LICENSEE EVENT REPORT (LER)
U.S. NUCLEAR REGULATORY COMMISSION 1. FACILITY NAME 2. DOCKET I LER NUMBER 3. PAGE YEAR REVISION NUMBER SEQUENTIAL NUMBER Grand Gulf Nuclear Station, Unit 1 05000416 2005 003 00 4
OF 4
The condition would not have prevented the fulfillment of the safety function and did not result in a safety system functional failure as defined by 10 CFIR 5CY 73(a)(2)(v).
G.
ADDITIONAL INFORMATION
There have been no LERs written on a similar GGNS event in the past two years. Additionally reviewed CR's in the past 2 years and found no similar setpoint issues.
LER 2005-003-00