05000296/LER-2009-003, Brown Ferry, Unit 3 Re Reactor Core Isolation Cooling System Inoperable Longer than Allowed by the Technical Specifications

Brown Ferry, Unit 3 Re Reactor Core Isolation Cooling System Inoperable Longer than Allowed by the Technical Specifications

ML101480066
Person / Time
Site:	Browns Ferry  (DPR-068)
Issue date:	05/24/2010
From:	Polson K Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 09-003-00
Download: ML101480066 (7)

LER-2009-003, Brown Ferry, Unit 3 Re Reactor Core Isolation Cooling System Inoperable Longer than Allowed by the 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)(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
2962009003R00 - NRC Website

text

Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 May 24, 2010 10 CFR 50.73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D. C. 20555-0001 Browns Ferry Nuclear Plant, Unit 3 Facility Operating License No. DPR-68 NRC Docket No. 50-296

Subject:

Licensee Event Report 50-29612009-003-00 The Tennessee Valley Authority (TVA) is submitting the enclosed Licensee Event Report (LER) to provide details of a condition prohibited by Technical Specifications due to an event involving an inoperable Reactor Core Isolation Cooling (RCIC) system. Initially, TVA determined that the event was not reportable to the Nuclear Regulatory Commission (NRC) under 10 CFR 50.73. However, as a result of preparing answers to questions from the NRC, on March 25, 2010, TVA concluded that a violation of Technical Specifications occurred. Therefore, TVA is submitting this report in.accordance with 10 CFR 50.73(a)(2)(i)(B), as any operation or condition prohibited by the plant's Technical Specifications.

By July 15, 2010, TVA will supplement this LER to provide a final summary of the information discussed with the NRC during the March 25, 2010, telephone conference call and provide additional information regarding the contributing cause. Should you have any questions concerning this submittal, please contact S. T. Day Jr., Acting Site Licensing and Industry Affairs Manager, at (256) 729-2636.

Respectfully,

? J.1 Pos dIs Vice President cc: See page 2 logKf

U.S. Nuclear Regulatory Commission Page 2 May 24, 2010 Enclosure cc (w/ Enclosure):

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

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 08/31/2010 (9-2007)

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information (See reverse for required number of collection.

3. PAGE Browns Ferry Nuclear Plant Unit 3 05000296 1 of 5

4. TITLE: Reactor Core Isolation Cooling System Inoperable Longer Than Allowed By the Technical Specifications

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR N/A N/A NUMBER NO.

FACILITY NAME DOCKET NUMBER 08 26 2009 2009 003 00 05 24 2010 N/A N/A

9. OPERATING MODE

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

[E 20.2203(a)(3)(i)

El 50.73(a)(2)(i)(C)

E] 50.73(a)(2)(vii)

El 20.2201(d)

El 20.2203(a)(3)(ii)

E] 50.73(a)(2)(ii)(A)

E] 50.73(a)(2)(viii)(A)

El 20.2203(a)(1)

[E 20.2203(a)(4)

[] 50.73(a)(2)(ii)(B)

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

El 20.2203(a)(2)(i)

El 50.36(c)(1)(i)(A)

El 50.73(a)(2)(iii)

[E 50.73(a)(2)(ix)(A)

10. POWER LEVEL [E

20.2203(a)(2)(ii)

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

E] 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)

[E 20.2203(a)(2)(iv)

El 50.46(a)(3)(ii)

El 50.73(a)(2)(v)(B)

El 73.71(a)(5) 100 [1 20.2203(a)(2)(v)

El 50.73(a)(2)(i)(A)

El 50.73(a)(2)(v)(C)

El OTHER El 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)

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

Spedty in Abstract belw or in NRC Form 386A

12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (Include Area Code)

Steve Austin, Licensing Engineer 256-729-2070CAUSE SYSTEM COMPONENT MANU-REP

CAUSE

SYC M REPORTABLE FACTURER TO EPIX FACTURER TO EPIX

14. SUPPLEMENTAL REPORT EXPECTED

15. EXPECTED MONTH DAY YEAR SUBMISSION Z

YES (If yes, complete 15. EXPECTED SUBMISSION DATE)

[]

NO DATE 07 15 2010 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)

On August 26, 2009, Browns Ferry Nuclear Plant (BFN) personnel identified an unexpected level of instability in the Reactor Core Isolation Cooling (RCIC) system flow and turbine response following a Unit 3 manual reactor scram that occurred on August 24, 2009. This occurred during a post scram review of the RCIC system operating parameters. During the injection sequence, the RCIC system flow oscillated between approximately 300 and 900 gallons per minute (gpm). BFN personnel evaluated the phenomena and determined the RCIC system was capable of performing its design function and, thus, it was concluded that the RCIC system had been operable. On August 26, 2009, at approximately 1502 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.71511e-4 months <br /> Central Daylight Time (CDT), Operations personnel entered Mode 2, commencing startup operations. Unit 3 was returned to service on August 28, 2009, at 1833 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.974565e-4 months <br /> CDT and remained at power until September 12, 2009, when it was removed from service for scheduled maintenance. During the September outage the RCIC Electric Governor-Remote (EG-R) was replaced and successfully tested.

On March 25, 2010, in response to questions from the NRC, the Tennessee Valley Authority (TVA) notified the NRC via conference telephone call that Unit 3 RCIC was inoperable longer than allowed by Technical Specification 3.5.3 during the period of August 26, 2009, through September 12, 2009. BFN also performed a Mode change on August 26, 2009, with the RCIC System inoperable. A failure analysis determined the oscillations were caused by a missing buffer piston and springs within the EG-R. The missing buffer piston and springs are required for stable operation. BFN personnel replaced the Unit 3 RCIC system EG-R hydraulic actuator. Following the replacement of the Unit 3 RCIC system EG-R hydraulic actuator, testing found the actuator exhibited stable turbine speed and flow during the reactor pressure vessel injection at power.

NRC FORM 366 (9-2007)

(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)

During the RPV injection on August 24, 2009, the RCIC system along with the HPCI system only injected for approximately 2.5 minutes. For long term operation such as maintaining water level with the RPV isolated, Operating Instruction, 3-01-71, Reactor Core Isolation Cooling system, provides instructions for operating the RCIC system in a manual mode upon malfunction of flow controller. Therefore, TVA concludes that there was no significant reduction in the protection of the public by this event.

A final summary of the information discussed with the NRC during the March 25, 2010, telephone conference call will be included in a revision to this LER

VI. CORRECTIVE ACTIONS

A.

Immediate Corrective Actions

On September 14, 2009, BFN replaced the Unit 3 RCIC system EG-R hydraulic actuator. The hydraulic actuator that was in place during the August 24, 2009, reactor scram was sent to the vendor for failure analysis and refurbishment.

B.

Corrective Actions to Prevent Recurrence Following the replacement of the Unit 3 RCIC system EG-R hydraulic actuator, a RPV injection test was conducted on September 21, 2009. The hydraulic actuator exhibited stable turbine speed and flow during the RPV injection.

VII. ADDITIONAL INFORMATION

A.

Failed Components None B.

PREVIOUS LERS ON SIMILAR EVENTS None C.

Additional Information

Corrective action document for this report is Problem Evaluation Report 213088.

D.

Safety System Functional Failure Consideration:

This event is not classified as a safety system functional failure according to NEI 99-02.

E.

Scram With Complications Consideration:

This LER does not describe a complicated scram according to NEI 99-02.

VIII. COMMITMENTS

By July 15, 2010, TVA will supplement this LER to provide a final summary of the information discussed with the NRC during the March 25, 2010, telephone conference call with NRC and provide additional information regarding the contributing cause.