05000259/LER-2015-004, Regarding Containment Atmospheric Dilution B Train Supply System Inoperable Longer than Allowed by Technical Specifications

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Regarding Containment Atmospheric Dilution B Train Supply System Inoperable Longer than Allowed by Technical Specifications
ML15334A329
Person / Time
Site: Browns Ferry Tennessee Valley Authority icon.png
Issue date: 11/30/2015
From: Bono S
Tennessee Valley Authority
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 15-004-00
Download: ML15334A329 (8)


LER-2015-004, Regarding Containment Atmospheric Dilution B Train Supply System Inoperable Longer than Allowed by Technical Specifications
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications

10 CFR 50.73(a)(2)(v), Loss of Safety Function

10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown

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)(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)
2592015004R00 - NRC Website

text

Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 November 30, 2015 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Units 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 50-259/2015-004-00 The enclosed Licensee Event Report provides details of Containment Atmospheric Dilution B train supply system inoperable longer than allowed by Technical Specifications. The Tennessee Valley Authority is submitting this report in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.73(a)(2)(i)(B), as any operation or condition which was prohibited by the plant's Technical Specifications, and 10 CFR 50.73(a)(2)(v)(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 control the release of radioactive material or to 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 50-259/2015-004 Containment Atmospheric Dilution B Train Supply System Inoperable Longer Than Allowed by Technical Specifications cc (w/ Enclosure):

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

ENCLOSURE Browns Ferry Nuclear Plant Units 1, 2, and 3 Licensee Event Report 50-259/2015-004-00 Containment Atmospheric Dilution B Train Supply System Inoperable Longer Than Allowed by Technical Specifications See Enclosed

NRC FORM 366 (02-2014)

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (02-2014)

LICENSEE EVENT REPORT (LER)

APPROVED BY OMB NO. 3150-0104 EXPIRES 10/31/2017

, 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 6
4. TITLE:

Containment Atmospheric Dilution B Train Supply System Inoperable Longer Than Allowed by Technical Specifications

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 09 29 2015 2015 - 004 - 00 11 30 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 Although the internal and external OE review found similar conditions related to the search terms such as holes in piping due to corrosion, core drilling, and mechanical damage occurring during excavation, none were determined to have been applicable to preventing the hole from occurring in the Train B CAD system supply line. The causes of the two OE events described above were not associated with identification of piping, and BFN uses various methods to mitigate buried piping damage both prior to and during excavation. Therefore, no corrective actions were deemed necessary to address these OE.

B. Additional Information

There is no additional information.

C. Safety System Functional Failure Consideration:

LCO 3.6.3.1 states that Two CAD subsystems must be OPERABLE. This ensures operation of at least one CAD subsystem in the event of a worst case single active failure. Operation of at least one CAD subsystem is designed to maintain primary containment post-LOCA oxygen concentration <5.0 v/o for 7 days. The CAD B train was considered inoperable from an indeterminate date in the past until the piping was repaired and returned to service on October 10, 2015. This is in violation of Action A.1 which states, If one CAD subsystem is inoperable, it must be restored to OPERABLE status within 30 days. In the past three years, the CAD A train was also considered unavailable from July 29, 2013, at 0730 CDT to August 7, 2013, at 1515 CDT. Actions B.1 and B.2 requires the ability to control the hydrogen control function via alternate capabilities be verified by administrative means within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Action C.1 states, If any Required Action cannot be met within the associated Completion Time, the plant must be brought to a MODE in which the LCO does not apply.

Therefore, the above LCO actions were not met.

Although surveillances were completed satisfactorily, it cannot be concluded that with the hole in the pipe that the CAD B Train would have met its mission time and provided seven days of nitrogen during accident conditions. Therefore, with both CAD A and B trains inoperable/unavailable for a period of nine days in the past three years, this condition is considered to be a Safety System Function Failure, in accordance with NUREG-1022.

D. Scram with Complications Consideration:

This event did not result in a reactor scram.

VIII. COMMITMENTS

There are no new commitments.