05000445/LER-2012-001, For Comanche Peak, Unit 1, Regarding Unanalyzed Condition Discovered for the Normally Open Battery Room Fire and Cable Spread Room Doors Close on Momentary Loss of Power
| ML12128A427 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 04/30/2012 |
| From: | Madden F Luminant Generation Co, Luminant Power |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CP-201200270, TXX-12040 LER 12-001-00 | |
| Download: ML12128A427 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 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)(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 |
| 4452012001R00 - NRC Website | |
text
Rafael Flores Luminant Power Senior Vice President P 0 Box 1002
& Chief Nuclear Officer 6322 North FM 56 rafael.flores@Luminant.com Glen Rose, TX 76043 Luminant 2548975550 C 817 559 0403 F 254 897 6652 CP-201200270 Ref. #
Log # TXX-12040 April 30, 2012 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT DOCKET NOS. 50-445 AND 50-446 UNANALYZED CONDITION DISCOVERED FOR THE NORMALLY OPEN BATTERY ROOM FIRE AND CABLE SPREAD ROOM DOORS CLOSE ON MOMENTARY LOSS OF POWER LICENSEE EVENT REPORT 445/12-001-00
Dear Sir or Madam:
Pursuant to 10CFR50.73(a)(2)(ii)(B), Luminant Generation Company LLC (Luminant Power) hereby submits enclosed Licensee Event Report (LER) 445/12-001-00, "Unanalyzed Condition Discovered for the Normally Open Battery Room Fire and Cable Spread Room Doors Close on Momentary Loss of Power" for Comanche Peak Nuclear Power Plant (CPNPP) Units 1 and 2. This event did not affect the health and safety of the public or plant personnel.
This communication contains no licensing basis commitments regarding Comanche Peak Units 1 and 2.
Should you have any questions, please contact Ms. Tamera J. Ervin-Walker at (254)897-6902.
Sincerely, Luminant Generation Company LLC Rafael Flows By:
yf~b '-,2,.._
Fyred W. Madden Director, Oversight & Regulatory Affairs TJEW Enclosure
- - LER 1-12-001-00 Unanalyzed Condition Discovered for the Normally Open Battery Room Fire and Cable Spread Room Doors Close on Momentary Loss of Power c -
E. E. Collins, Region IV Balwant Singal, NRR Resident Inspectors, Comanche Peak A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway - Comanche Peak Diablo Canyon-Palo Verde San Onofre - South Texas Project Wolf Creek
Enclosure to TXX-12040 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (10-2010)
EXPIRES:l 0/31/2013
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Comanche Peak Nuclear Power Plant (CPNPP) Unit 1 05000 445 11 OF6
- 4. TITLE UNANALYZED CONDITION DISCOVERED FOR THE NORMALLY OPEN BATTERY ROOM FIRE AND CABLE SPREAD ROOM DOORS CLOSE ON MOMENTARY LOSS OF POWER
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCUMENT NUMBER NUMBER NO.
CPNPP Unit 2 05000 446 03 01 2012 2012 001 00 04 30 2012 FACILITY NAME DOCUMENTNUMBER
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
[]
20.2201(b)
[]
20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[] 50.73(a)(2)(vii) 1 Fl 20.2201(d)
E] 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
E] 20.2203(a)(1)
El 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i)
[
50.36(c)(1)(i)(A)
[J 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL
[] 20.2203(a)(2)(ii)
[] 50.36(c)(1)(ii)(A)
[] 50.73(a)(2)(iv)(A)
E] 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
[] 50.36(c)(2)
[]
50.73(a)(2)(v)(A)
El 73.71(a)(4) 100
[] 20.2203(a)(2)(iv)
[] 50.46(a)(3)(ii)
[]
50.73(a)(2)(v)(B)
El 73.71(a)(5)
El 20.2203(a)(2)(v)
[]
50.73(a)(2)(i)(A)
LI 50.73(a)(2)(v)(C)
[
OTHER [Z
20.2203(a)(2)(vi)
E] 50.73(a)(2)(i)(B)
E:]
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 DAY YEAR r-- S (SUBMISSION El.
YES (If yes, complefe 15. EXPECTED SUBMISS/ON DATE) l NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines On 3/1/2012, at 1353 hours0.0157 days <br />0.376 hours <br />0.00224 weeks <br />5.148165e-4 months <br />, an issue was identified with the doors for the safety related battery rooms and their normal position. Several doors to the battery rooms are held open via electromagnetic door devices. At the time, it was thought that there was no uninterruptible power to the door mechanisms, and that all the doors are expected to close in the event of a loss of offsite power (LOOP). Inadvertent closure of the doors following a momentary loss of power prevents their design function of venting hydrogen from the battery rooms and providing tornado venting pathways in the building. Compensatory measures were taken to secure the doors open to maintain the hydrogen purging and tornado venting functions. A roving fire watch was implemented to comply with the fire protection function of the doors. As an extent of condition on 3/12/12, the cable spread room (CSR) doors were also identified to utilize the same design and electrical supply configuration as the battery room doors.
The CSR is located above the battery rooms in the Electric and Control (E&C) Building. Contingency actions were put in place to secure the CSR doors open and implement a fire impairment in the event of a tornado risk. On 4/11/12, it was discovered that the battery room and CSR doors have small battery backup units which could sustain the doors with adequate power to maintain their position for 45 seconds sufficient to allow AC power to be restored through the Emergency Diesel Generators (EDGs) during a tornado. However, the backup units were found to be in a state of degradation, challenging the ability of the backup batteries to maintain their power supply to the door hold-open devices during a tornado event. No recent preventive maintenance work orders exist for the inspection or replacement of these units. There were no actual safety consequences impacting the plant or public safety as a result of these events. The cause was a design process legacy issue, and current design processes are significantly different from those in place during early operation of CPNPP. The specific conditions have been addressed in the corrective action program and, along with current programs and practices, are adequate to prevent future occurrences. All times in this report are approximate and Central Time unless noted otherwise.
(If more space is required, use additional copies of SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES:
On March 1, 2012, at 1353 hours0.0157 days <br />0.376 hours <br />0.00224 weeks <br />5.148165e-4 months <br />, an issue was identified by engineering (Utility, Non-licensed) with the doors [EIIS: (DR)] for the safety related battery rooms and their normal position. Several doors to the battery rooms were found to be held open via electromagnetic door devices. These hold-open devices utilize an electromagnetic lock, which requires a continuous supply of low voltage direct current (DC) power to generate the magnetic forces restraining the doors in the open position. Inadvertent closure of the doors following a momentary loss of power could prevent their design function fulfillment. Door closure is required in response to a fire detection and protection system actuation to protect the battery rooms from fire damage. Conversely, the doors are maintained open for the dual purposes of 1) allowing airflow into the room to support the room exhaust heating, ventilating, and air conditioning (HVAC) within the room (and credited for the removal of hydrogen accumulation), and 2) reduce differential pressures across the rooms structural surfaces during tornado events. Further research determined the hold-open devices are powered from only non-vital AC power sources [EIIS: (JX)] (which is converted into DC power within the fire panel) and thought not to include battery backup protection.
Compensatory measures were implemented later that day (March 1, 2012) to secure the doors open to maintain the hydrogen purging function. A fire watch was implemented to comply with the fire protection function of the doors.
(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)
The cause analysis for the existing design without supporting PMs are:
the failure of the responsible engineer for the device installation to involve the cognizant individuals in the design phase as well as failure to institute changes to the design documents utilized by later tornado venting engineers which may have identified the error in LOOP protection, and the failure of an interdisciplinary group involved in the original installation to identify the required LOOP protection for the system.
V. CORRECTIVE ACTIONS
On 3/1/2012 at 1913 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.278965e-4 months <br />, the battery rooms were restrained and on 3/2/2012 at 1532, the fire impairments were implemented including a roving fire watch to ensure fire protection requirements are maintained.
After the cable spread room doors were also identified to utilize the same closure mechanism as the battery room doors on 3/12/12 at 1714 hours0.0198 days <br />0.476 hours <br />0.00283 weeks <br />6.52177e-4 months <br />, actions were implemented to provide contingencies to secure the CSR doors open and implement a fire impairment during periods of heightened tornado risk.
The cause was a design process legacy issue, and current design processes are significantly different from those in place during early operation of CPNPP. The specific conditions have been addressed in the corrective action program and, along with current programs and practices, are adequate to prevent future occurrences.
Existing batteries will be replaced as required and PMs will be created to inspect and replace controller panel batteries for fulfillment of tornado venting function.
VI. PREVIOUS SIMILAR EVENTS
There have been no previous similar reportable events at CPNPP in the last three years.