05000446/LER-2013-001, (Cnpnpp) Regarding Unit 2 Hot Shutdown Panel Transfer Switch Inoperable Due to Wiring Error
| ML13079A332 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 03/07/2013 |
| From: | Madden F, Flores R Luminant Power, Luminant Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CP-201300170, TXX-13028 LER 13-001-00 | |
| Download: ML13079A332 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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 |
| 4462013001R00 - NRC Website | |
text
Luminant Rafael Flores Senior Vice President
& Chief Nuclear Officer rafael.flores@luminant.com Luminant Power P 0 Box 1002 6322 North FM 56 Glen Rose, TX 76043 T 254 897 5590 C 817 559 0403 F 254 897 6652 CP-201300170 TXX-13028 Ref. #
10CFR50.73 March 7, 2013 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT (CPNPP)
DOCKET NO. 50-446 UNIT 2 HOT SHUTDOWN PANEL TRANSFER SWITCH INOPERABLE DUE TO WIRING ERROR LICENSEE EVENT REPORT 446/13-001-00
Dear Sir or Madam:
Pursuant to 10CFR50.73(a)(2)(i)(B), Luminant Generation Company LLC (Luminant Power) hereby submits enclosed Licensee Event Report (LER) 446/13-001-00, "Unit 2 Hot Shutdown Panel Transfer Switch Inoperable due to Wiring Error" for Comanche Peak Nuclear Power Plant (CPNPP) Unit 2.
This communication contains no licensing basis commitments regarding CPNPP Units I and 2.
Should you have any questions, please contact Tim Hope at (254) 897-6370.
Sincerely, Luminant Generation Company LLC Rafael Flores By:- &
,2QaU.-.
/Fred W. Madden Director, Oversight & Regulatory Affairs A member of the STARS Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde
- San Onofre. South Texas Project
- Wolf Creek
U. S. Nuclear Regulatory Commission TXX-13028 Page 2 of 2 03/07/2013 Enclosure c -
E. E. Collins, Region IV B. K. Singal, NRR Resident Inspectors, Comanche Peak
Enclosure to TXX-13028 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES:10/31/2013 (10-2010)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the BudgeteW information collection.
- 3. PAGE
- 4. TIT LE0 Comanche Peak Nuclear Power Plant (CPNPP) Unit 2 05000446 1 OF 5 UNIT 2 HOT SHUTDOWN PANEL TRANSFER SWITCH INOPERABLE DUE TO WIRING ERROR
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR DOCUMENTNUMBER 01 06 2013 13 001 00 03 07 2013 FACILITY NAME DOCUMENT NUMBER
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
E] 20.2201(b)
[]
20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[]
50.73(a)(2)(vii) 1
[] 20.2201(d)
[]
20.2203(a)(3)(ii)
[]
50.73(a)(2)(ii)(A)
[]
50.73(a)(2)(viii)(A)
E] 20.2203(a)(1)
E:
20.2203(a)(4)
El 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B)
F[] 20.2203(a)(2)(i)
[]
50.36(c)(1)(i)(A)
[]
50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL
[] 20.2203(a)(2)(ii)
E]
50.36(c)(1)(ii)(A)
E]
50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
[] 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
[]
73.71(a)(4) 100 El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5)
El 20.2203(a)(2)(v)
E] 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
[J 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
VOLUNTARY LER
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (Include Area Code)
Timothy A. Hope, Manager, Nuclear Licensing 254-897-6370CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX I
FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH D
YEAR E
YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
I NO DATE SUBMISSION ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On January 6, 2013, Comanche Peak Nuclear Power Plant (CPNPP) Unit 2 was in Mode 1 operating at 100% power. At 0345 hours0.00399 days <br />0.0958 hours <br />5.704365e-4 weeks <br />1.312725e-4 months <br /> while performing surveillance testing on the Hot Shutdown Panel (HSP), the Turbine Driven Auxiliary Feedwater Pump (TDAFWP) steam supply valve control transfer switch was placed in the HSP position. During the test, the steam supply valve for the TDAFWP pump opened when it should have remained closed. Therefore, the TDAFWP steam supply control transfer switch was declared inoperable. This condition existed for greater than the allowable Technical Specification (TS) required action completion of time of 30 days for TS 3.3.4, Remote Shutdown System.
The cause of this event was the new circuit wiring at the Unit 2 HSP was landed on incorrect terminals. This error was not found during the verification of termination of the new circuit wiring. The post work testing requirements were ineffective in the discovery of the error.
Immediate corrective actions included correct termination of the cables and completion of the surveillance testing of the HSP. As a part of the CPNPP Corrective Action Program, procedures will be revised to ensure that the conduct of field work and inspection of cable terminations is correct and post work testing training will ensure that all aspects of the modified circuit are tested.
All times in this report are approximate and Central Time unless noted otherwise.
NRC FORM 366 (10-2010)
PRINTED ON RECYCLED PAPER (If more space is required, use additional copies of SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES:
On January 6, 2013, Comanche Peak Nuclear Power Plant (CPNPP) Unit 2 was in Mode 1 operating at 100% power. At 0345 hours0.00399 days <br />0.0958 hours <br />5.704365e-4 weeks <br />1.312725e-4 months <br /> while performing surveillance testing on the Hot Shutdown Panel (HSP), the Turbine Driven Auxiliary Feedwater Pump (TDAFWP) steam supply valve control transfer switch [ElIS:
(BA)(P)(V)(HIS)] was placed in the HSP position. During the test, the steam supply valve for the TDAFWP pump opened when it should have remained closed. Therefore, the TDAFWP steam supply control transfer switch was declared inoperable.
The circuit for one of the TDAFWP steam supply valves was being modified to assure that, in the scenarios that credit the TDAFWP, the valve would not be unintentionally kept closed by an external hot short. When the valve is needed to open, power needs to be removed from the circuit. The new cable installation was partially completed prior to the start of the Unit 2 refueling outage (2RF1 3) when two cables were pulled to a cable tray above the HSP on September 19, 2012. The two cables were properly labeled and waiting for termination during 2RF13.
During 2RF13, preparations were made to the two new cables for termination in the HSP cabinet. During this preparation the two cables were unlabeled at the same time while being moved inside the HSP cabinet.
Once the new cables were inside the cabinet the new conductors were mislabeled and terminated on October 8, 2012. Quality control inspections did not determine that the new conductors were terminated incorrectly, since the mislabeled conductors were on the correct termination for the label of the cable.
The testing requirements of the modification were to functional stroke the TDAFWP steam supply valve and perform cable continuity checks. The scope of the modification was to replace existing cable with new cable that was designed to prevent a hot short from occurring. The post work test specified for this modification was to stroke the TDAFWP steam admission valve. The valve was only stroked from the control room control station. This test was performed during 2RF13 prior to entering Mode 3 on October 31, 2012. This method of testing did not test all portions of the control circuit where cable and wiring was replaced.
Consequently an error in wiring in a portion of the circuit not used to stroke the valve was not detected by the post work test.
On January 9, 2013, it was determined that the two new conductors had been mislabeled and landed on their opposite terminals. The conductors were correctly relabeled and terminated in accordance with the modification. This corrected the condition and the surveillance testing on the HSP was completed with satisfactory results and the TDAFWP steam supply control transfer switch was declared operable.
(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)
Modifications that will be implemented in the upcoming Unit 1 refueling outage have been reviewed and revised to ensure proper control of cable/conductor labeling and the adequacy of post modification testing for verifying the function of the disturbed circuits.
As a part of the CPNPP Corrective Action Program, procedures will be revised to ensure positive control of labels for cables. Procedures will require a continuity check to verify cable/conductor ends when labels are placed on an unlabeled cable if the labels are removed or become detached. Post work testing training will be conducted to ensure that all aspects of testing of disturbed circuits for electrical modifications are addressed.
VI. PREVIOUS SIMILAR EVENTS
There have been no previous similar reportable events at CPNPP in the last three years.PRINTED ON RECYCLED PAPER