05000296/LER-2007-002, Regarding Unplanned Inoperability of the Unit 3 High Pressure Coolant Injection System Due to Loss of 120 Vac Instrument Power

Regarding Unplanned Inoperability of the Unit 3 High Pressure Coolant Injection System Due to Loss of 120 Vac Instrument Power

ML072681181
Person / Time
Site:	Browns Ferry
Issue date:	09/24/2007
From:	O'Grady B Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 07-002-00
Download: ML072681181 (7)

LER-2007-002, Regarding Unplanned Inoperability of the Unit 3 High Pressure Coolant Injection System Due to Loss of 120 Vac Instrument Power

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 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)(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
2962007002R00 - NRC Website

text

September 24, 2007 U.S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN: Document Control Desk Mail Stop: OWFN, P1-35 Washington, D. C. 20555-0001

Dear Sir:

TENNESSEE VALLEY AUTHORITY - BROWNS FERRY NUCLEAR PLANT (BFN) -

UNIT 3 - DOCKET 50-296 - FACILITY OPERATING LICENSE DPR LICENSEE EVENT REPORT (LER) 50-296/2007-002-00 The enclosed report provides details of an unplanned inoperability of the Unit 3 High Pressure Coolant Injection system due to loss to 120 VAC instrument power. TVA is reporting this in accordance with 10 CFR 50.73(a)(2)(v)(B) and (D) as; any event of condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to: remove residual heat; and to mitigate the consequences of an accident. There are no commitments contained within this letter.

Sincerely, Original signed by:

Brian O'Grady cc: See page 2

U.S. Nuclear Regulatory Commission Page 2 September 24, 2007 Enclosure cc (Enclosure):

Ms. Eva Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)

One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970

U.S. Nuclear Regulatory Commission Page 3 September 24, 2007 DTL:JEE:SWA:BAB cc:

Gordon Arent, Unit 2, EQB Bldg.-WBN R. H. Bryan, Jr., LP 4J-C W. R. Campbell, Jr. LP 6A-C J. R. Douet, LP 6A-C J. C. Fornicola, LP 6A-C R. G. Jones, POB 2C-BFN G. V. Little, NAB 1D-BFN R. F. Marks, Jr., PAB 1C-BFN D. C. Matherly, BFT 2A-BFN B. A. Wetzel, BR 4X-C S. A. Vance, WT 6A-K E. J. Vigluicci, ET 11A-K NSRB Support, LP 5M-C EDMS WT CA-K, s: lic/submit/ler296 2007-02.doc

NRC FORM 366 (6-2004)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (6-2004)

LICENSEE EVENT REPORT (LER)

(See reverse for required number of digits/characters for each block)

APPROVED BY OMB NO. 3150-0104 EXPIRES 06/30/2007 Estimated burden per response to comply with this mandatory collection request: 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch (T-5 F52),

U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME Browns Ferry Unit 3

2. DOCKET NUMBER 05000296

3. PAGE 1 of 4

4. TITLE: Unplanned Inoperability of the Unit 3 High Pressure Coolant Injection System Due to Loss to 120 VAC Instrument Power

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

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

MONTH DAY YEAR FACILITY NAME None DOCKET NUMBER N/A 07 24 2007 2007-002-00 09 24 2007 FACILITY NAME None DOCKET NUMBER N/A

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

9. OPERATING MODE 1

20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 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) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii)

X 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)

OTHER

10. POWER LEVEL 100 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B)

X 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 366A) (17) Core Cooling systems remained operable. Therefore, TVA concludes that the health and safety of the public was not affected by this event.

VI. CORRECTIVE ACTIONS

A.

Immediate Corrective Actions

The cleared fuse was replaced. The ECCS inverter output voltage and frequency was monitored for approximately one hour with the replacement fuse in service.

B.

Corrective Actions to Prevent Recurrence (1)

TVA will revise the operating instructions to require the affected ECCS ATU Inverters de-energized prior to a scheduled transfer of the input voltage source.

VII. ADDITIONAL INFORMATION

A.

Failed Components BUSS Semiconductor fuse, part No. FWH-125A, 550V AC/DC manufactured by Bussmann, Inc.

B.

Previous LERs on Similar Events None.

C.

Additional Information

Corrective action document for this event is PER 127921.

D.

Safety System Functional Failure Consideration:

This event involved a safety system functional failure as referenced in 10 CFR 50.73(a)(2)(v), and will be included in Performance Indicator Reporting in accordance with NEI 99-02.

E.

Scram With Complications Consideration:

This event did not result in a complicated scram as defined in NEI 99-02.

VIII.

COMMITMENTS

None.

(1) TVA does not consider these corrective actions as regulatory requirements. The completion of these actions will be tracked in TVA's Corrective Action Program.