05000259/LER-2015-003, Regarding Loss of Cooling to the Unit 1 and Unit 2 Shutdown Board Rooms Due to Fouled Chiller Coils

Regarding Loss of Cooling to the Unit 1 and Unit 2 Shutdown Board Rooms Due to Fouled Chiller Coils

ML15257A131
Person / Time
Site:	Browns Ferry
Issue date:	09/14/2015
From:	Bono S Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 15-003-00
Download: ML15257A131 (9)

LER-2015-003, Regarding Loss of Cooling to the Unit 1 and Unit 2 Shutdown Board Rooms Due to Fouled Chiller Coils

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 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)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x)
2592015003R00 - NRC Website

text

Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 September 14, 2015 ATTN : Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 1, 2, and 3 10 CFR 50.73 Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296

Subject:

Licensee Event Report 50-259/2015-003-00 The enclosed Licensee Event Report provides details of the inoperability of both Unit 1 and 2 Control Bay Chillers, resulting in a loss of cooling to the Shutdown Board Rooms. The Tennessee Valley Authority (TVA) is submitting this report in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50. 73(a)(2)(v)(A), (B), (C), and (D),

as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to shut down the reactor and maintain it in a safe shutdown condition, remove residual heat, control the release of radioactive material, or mitigate the consequences of an accident.

There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact J. L. Paul, Nuclear Site Licensing Manager, at (256) 729-2636.

Enclosure:

Licensee Event Report 50-259/2015-003 Loss of Cooling to the Unit 1 and Unit 2 Shutdown Board Rooms Due To Fouled Chiller Coils.

cc (w/ Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant

ENCLOSURE Browns Ferry Nuclear Plant Unit 1, 2, and 3 Licensee Event Report 50-259/2015-003-00 Loss of Cooling to the Unit 1 and Unit 2 Shutdown Board Rooms Due To Fouled Chiller Coils See Enclosed

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (01-2014)

LICENSEE EVENT REPORT (LER)

APPROVED BY OMB NO. 3150-0104 EXPIRES 01/31/2017

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

1. FACILITY NAME Browns Ferry Nuclear Plant (BFN), Unit 1

2. DOCKET NUMBER 05000259

3. PAGE 1 of 7

4. TITLE: Loss of Cooling to the Unit 1 and Unit 2 Shutdown Board Rooms Due To Fouled Chiller Coils

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

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

MONTH DAY YEAR BFN, Unit 2 05000260 7

14 2015 2015 - 003 - 00 9

14 2015 BFN, Unit 3 05000296

9. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 20.2201(b) 20.2201(d) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)(2)(vi) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1)(i)(A) 50.36(c)(1)(ii)(A) 50.36(c)(2) 50.46(a)(3)(ii) 50.73(a)(2)(i)(A) 50.73(a)(2)(i)(B) 50.73(a)(2)(i)(C) 50.73(a)(2)(ii)(A) 50.73(a)(2)(ii)(B) 50.73(a)(2)(iii) 50.73(a)(2)(iv)(A) 50.73(a)(2)(v)(A) 50.73(a)(2)(v)(B) 50.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(ix)(A) 50.73(a)(2)(x) 73.71(a)(4) 73.71(a)(5)

OTHER Specify in Abstract below or in VII. Additional Information:

A. Previous Similar Events at the same plant:

A review of the BFN CAP and Licensee Event Reports (LERs) for Units 1, 2, and 3 revealed no failures BFN CB CHLR systems for the last five years which were attributable to condenser fouling.

B. Additional Information

There is no additional information.

C. Safety System Functional Failure Consideration:

This event resulted in the concurrent inoperability of all four BFN, Unit 1 and 2, 4kV SBDs. These electrical boards supply power to multiple safety-related systems including, but not limited to:

a. SLC b. RHR c. DGs d. CS These and other systems powered by BFN, Unit 1 and 2, 4kV SDBs are required in order to shut down the reactor and maintain it in a safe shutdown condition, remove residual heat, or mitigate the consequences of an accident.

This event also resulted in inoperability of two SGT trains. The SGT provides a means for minimizing the release of radioactive material from the containment to the environs by filtering and exhausting the air from any or all zones of the Reactor Building and maintaining the building at a negative pressure during containment isolation conditions. Two operable trains of SGT are required for minimum acceptable flow, under these conditions, in order to control the release of radioactive material. Therefore, in accordance with NUREG-1022, this event is considered a safety system functional failure.

D. Scram with Complications Consideration:

This event did not result in a reactor scram.

VIII. COMMITMENTS

There are no new commitments.