05000325/LER-2012-004, Regarding High Pressure Coolant Injection (HPCI) Inoperable Due to Erratic Governor Operation

Regarding High Pressure Coolant Injection (HPCI) Inoperable Due to Erratic Governor Operation

ML12193A092
Person / Time
Site:	Brunswick
Issue date:	06/29/2012
From:	Frisco J Progress Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BSEP 12-0074 LER 12-004-00
Download: ML12193A092 (6)

LER-2012-004, Regarding High Pressure Coolant Injection (HPCI) Inoperable Due to Erratic Governor Operation

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
3252012004R00 - NRC Website

text

Progress Energy JUN 2,9 2012 SERIAL: BSEP 12-0074 10 CFR 50.73 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

Subject:

Brunswick Steam Electric Plant, Unit No. 1 Renewed Facility Operating License No. DPR-71 Docket No. 50-325 Licensee Event Report 1-2012-004 Ladies and Gentlemen:

In accordance with the Code of Federal Regulations, Title 10, Part 50.73, Carolina Power

& Light Company, now doing business as Progress Energy Carolinas, Inc., submits the enclosed Licensee Event Report (LER). This report fulfills the requirement for a written report within sixty (60) days of a reportable occurrence.

Please refer any questions regarding this submittal to Mr. Lee Grzeck, Acting Supervisor -

Licensing/Regulatory Programs, at (910) 457-2487.

Sincerely, Joseph M. Frisco, Jr.

Plant General Manager Brunswick Steam Electric Plant MAT/mat

Enclosure:

Licensee Event Report Progress Energy Carolinas, Inc.

Brunswick Nuclear Plant P.O. Box 10429 Southport, NC 28461

-- F'z'

Document Control Desk BSEP 12-0074 / Page 2 cc (with enclosure):

U. S. Nuclear Regulatory Commission, Region II ATTN: Mr. Victor M. McCree, Regional Administrator 245 Peachtree Center Ave. N.E., Suite 1200 Atlanta, GA 30303-1257 U. S. Nuclear Regulatory Commission ATTN: Mr. Philip B. O'Bryan, NRC Senior Resident Inspector 8470 River Road Southport, NC 28461-8869 U. S. Nuclear Regulatory Commission (Electronic Copy Only)

ATTN: Mrs. Farideh E. Saba (Mail Stop OWFN 8G9A) 11555 Rockville Pike Rockville, MD 20852-2738 Chair - North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-0510

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

3. PAGE Brunswick Steam Electric Plant (BSEP), Unit 1 05000325 1 oF04

4. TITLE High Pressure Coolant Injection (HPCI) Inoperable due to Erratic Governor Operation

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED IIFACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR NUMBER NO.

FACILITY NAME DOCKET NUMBER 05 02 2012 2012 - 004 - 00 06 29 2012

9. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1E 20.2201(b)

El 20.2203(a)(3)(i)

[_ 50.73(a)(2)(i)(C)

El 50.73(a)(2)(vii)

El[ 20.2201 (d) n] 20.2203(a)(3)(ii)

El 50.73(a)(2)(ii)(A)

El 50.73(a)(2)(viii)(A)

LI 20.2203(a)(1)

LI 20.2203(a)(4)

El 50.73(a)(2)(ii)(B)

El 50.73(a)(2)(viii)(B)

LI 20.2203(a)(2)(i)

EL 50.36(c)(1)(i)(A)

El 50.73(a)(2)(iii)

El 50.73(a)(2)(ix)(A)

10. POWER LEVEL LI 20.2203(a)(2)(ii)

El 50.36(c)(1)(ii)(A)

El 50.73(a)(2)(iv)(A)

E] 50.73(a)(2)(x)

El 20.2203(a)(2)(iii)

EL 50.36(c)(2)

El 50.73(a)(2)(v)(A)

El 73.71(a)(4) 037 [L 20.2203(a)(2)(iv)

LI 50.46(a)(3)(ii)

LI 50.73(a)(2)(v)(B)

[1 73.71(a)(5)

El 20.2203(a)(2)(v)

LI 50.73(a)(2)(i)(A)

LI 50.73(a)(2)(v)(C)

Ej OTHER El 20.2203(a)(2)(vi)

[

50.73(a)(2)(i)(B)

[

50.73(a)(2)(v)(D)

Specify in Abstract below or in After the flow controller had been placed in manual and speed adjusted to 2500 rpm, the HPCI governor exhibited erratic behavior characterized by momentary fluctuations in speed between 400 rpm and 2500 rpm (i.e., with slight overshoot before settling back to 2500 rpm).

Trouble shooting activities were undertaken and, on May 5, 2012, the Ramp Generator Signal Converter (RGSC) and electronic governor - magnetic pickup (EGM) were replaced with spare units that had been warmed up and calibrated as a pair. After replacement of these items, HPCI was successfully tested per OPT-09.2. Bench testing of the RGSC and EGM revealed that the RGSC output voltage signal dropped off erratically with constant input current. The subject RGSC was sent to ATC Nuclear for vendor failure analysis and repair. The failure of the RGSC was caused by a failed operational amplifier. The cause of the operational amplifier failure was determined to be age-related based on the best available information.

Event Cause

The root cause of the erratic HPCI operation is the lack of a replacement preventive maintenance route for the RGSC. The observed erratic operation was a result of an age-related failure of the RGSC operational amplifier.

Safety Assessment

The safety significance of this event is minimal. The RCIC system, ADS, LPCI system, and CS system were operable at the time of the event.

Corrective Actions

The following corrective action has been completed.

• The Unit 1 HPCI EGM and RGSC were replaced.

The following corrective actions are planned.

• The Unit 2 HPCI RGSC is currently planned to be replaced during an online system outage in 2014.

• The Unit 1 RCIC RGSC is currently planned to be replaced during an online system outage in 2013.

• The Unit 2 RCIC RGSC is currently planned to be replaced during an online system outage in 2013.

• Replacement preventive maintenance routes will be established for the Unit 1 and 2 HPCI and RCIC RGSCs. These routes are currently planned to be established by October 11, 2012.

Previous Similar Events

A review of LERs for the past three years identified the following similar previous occurrences.

LER 1-2012-001, Manual Reactor Protection System Actuation in Anticipation of a Loss of Condenser Vacuum. This LER reported a February 22, 2012, manual Reactor Protection System (RPS) actuation on Unit 1,which was inserted in anticipation of a loss of condenser vacuum. The event was caused when balance of plant (BOP) bus Common C unexpectedly de-energized. The root cause of this event is inadequate preventive maintenance for the 4160/480V transformer associated with the Common C BOP bus. Corrective actions for this event focused on establishing appropriate preventive maintenance tasks for the 4160/480V transformers. As such, they could not have reasonably prevented the HPCI inoperability discussed in LER 1-2012-004.

" LER 2-2009-001, High Pressure Coolant Injection (HPCI) System Inoperable Due to Water in the HPCI Turbine Casing. This LER reported a January 27, 2009, inoperability of the HPCI system. The direct cause of the event was failure of the HPCI barometric condenser condensate pump. One of the root causes of the event was lack of preventive maintenance activities for the barometric condenser condensate pump and motor. Corrective actions for this event focused on establishing appropriate preventive maintenance tasks for the pump and motor. As such, they could not have reasonably prevented the HPCI inoperability discussed in LER 1-2012-004.

Commitments

No regulatory commitments are contained in this report.