05000259/LER-2013-004, Brown Ferry, Unit 1, Regarding High Pressure Coolant Injection System Declared Inoperable Due to Exceeding the Allotted Time Frame for Instrument Inoperability

Brown Ferry, Unit 1, Regarding High Pressure Coolant Injection System Declared Inoperable Due to Exceeding the Allotted Time Frame for Instrument Inoperability

ML13263A013
Person / Time
Site:	Browns Ferry  (DPR-033)
Issue date:	09/18/2013
From:	Polson K Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 13-004-00
Download: ML13263A013 (9)

LER-2013-004, Brown Ferry, Unit 1, Regarding High Pressure Coolant Injection System Declared Inoperable Due to Exceeding the Allotted Time Frame for Instrument Inoperability

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(i)(B), Prohibited by Technical Specifications
2592013004R00 - NRC Website

text

Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 September 18, 2013 10 CFR 50.73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 1 Renewed Facility Operating License No. DPR-33 NRC Docket No. 50-259

Subject:

Licensee Event Report 50-259/2013-004-00 The enclosed Licensee Event Report provides details of the High Pressure Coolant Injection System being declared inoperable due to exceeding the allotted time frame for instrument inoperability. 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)(v)(D).

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

Respectfully, K.J lson Vice President

Enclosure:

Licensee Event Report 50-259/2013-004 High Pressure Coolant Injection System Declared Inoperable Due to Exceeding the Allotted Time Frame for Instrument Inoperability cc (w/ Enclosure):

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

ENCLOSURE Browns Ferry Nuclear Plant Unit I Licensee Event Report 50-259/2013-004-00 High Pressure Coolant Injection System Declared Inoperable Due to Exceeding the Allotted Time Frame for Instrument Inoperability See Enclosed

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 Browns Ferry Nuclear Plant, Unit 1 05000259 1 of 7

4. TITLE: High Pressure Coolant Injection System Declared Inoperable Due to Exceeding the Allotted Time Frame for Instrument Inoperability

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MON YEAR YEAR SEQUENTIAL REV

MONTH, DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NO.

NIA 05000 FACILITY NAME DOCKET NUMBER 07 20 2013 2013 -

004 00 09 18 2013 N/A 05000

9. OPERATING MODE

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

C1 20.2203(a)(3)(i)

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

[I 50.73(a)(2)(vii)

El 20.2201(d) 0l 20.2203(a)(3)(ii)

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

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

El 20.2203(a)(1) 0l 20.2203(a)(4)

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

El 50.73(a)(2)(viii)(B) 0_ 20.2203(a)(2)(i) 0l 50.36(c)(1)(i)(A)

[I 50.73(a)(2)(iii)

El 50.73(a)(2)(ix)(A) 10, POWER LEVEL 0l 20.2203(a)(2)(ii)

C1 50.36(c)(1)(ii)(A)

[I 50.73(a)(2)(iv)(A)

[I 50.73(a)(2)(x) 0l 20.2203(a)(2)(iii)

[I 50.36(c)(2) 0l 50.73(a)(2)(v)(A)

El 73.71(a)(4)

[I 20.2203(a)(2)(iv)

El 50.46(a)(3)(ii) 0l 50.73(a)(2)(v)(B)

El 73.71(a)(5) 100

[] 20.2203(a)(2)(v) 0l 50.73(a)(2)(i)(A) 0l 50.73(a)(2)(v)(C)

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

El 50.73(a)(2)(i)(B) 0 50.73(a)(2)(v)(D)

Speifyin Abstract belo or in NRC Fonr 366A

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

Eric Bates, Licensing Engineer 256-614-7180C MANU-REPORTABLE

CAUSE

SYS OMPONENT MANU REPORTABLE

CAUSE

SYSTEM COMPONENT FACTURER TO EPIX TEMFACTURER TO EPIX

14. SUPPLEMENTAL REPORT EXPECTED

15. EXPECTED MONTH DAY YEAR SUBMISSION El YES (If yes, complete 15. EXPECTED SUBMISSION DATE) 0 NO DATE N/A N/A N/A ABSTRACT (Limit to 1400 spaces, i.e.. approximately 15 single-spaced typewritten lines)

On July 20, 2013, at 0338 hours0.00391 days <br />0.0939 hours <br />5.588624e-4 weeks <br />1.28609e-4 months <br /> Central Daylight Time (CDT), Operations personnel entered Technical Specification (TS) 3.3.5.1 Condition D due to the performance of surveillance procedure 1-SR-3.3.5.1.3(D), High Pressure Coolant Injection System Condensate Header Low Level Switch Calibration and Functional Test, requiring the High Pressure Coolant Injection (HPCI) System to be declared inoperable within one hour. At 0438 hours0.00507 days <br />0.122 hours <br />7.242063e-4 weeks <br />1.66659e-4 months <br /> CDT due to not meeting the required Completion Time, Browns Ferry Nuclear Plant, Unit 1, made an unplanned entry into TS 3.5.1 Condition C, due to the HPCI System being declared inoperable.

The root cause of this event was determined to be the failure to declare the HPCI System inoperable as part of the planned surveillance testing on the HPCI System condensate header low level switches.

Corrective actions to prevent recurrence were to revise surveillance procedures "High Pressure Coolant Injection System Condensate Header Low Level Switch Calibration and Functional Test" and "HPCI Suppression Chamber High Level Calibration and Functional Test" to require the HPCI System be declared inoperable prior to the performance of these surveillance procedures.

NRC FORM 366 (10-2010)

1.

Plant Operating Conditions Before the Event

At the time of the event, Browns Ferry Nuclear Plant (BFN), Unit 1, was in Mode 1 at approximately 100 percent rated thermal power.

Ill.

Description of Events A. Event:

On July 20, 2013, at 0438 hours0.00507 days <br />0.122 hours <br />7.242063e-4 weeks <br />1.66659e-4 months <br /> Central Daylight Time (CDT), BFN, Unit 1, entered an unplanned Technical Specification (TS) 3.5.1 Condition C due to not meeting the required Completion Time for TS 3.3.5.1 Condition D.

The Limiting Condition for Operation (LCO) 3.3.5.1 requires that the Emergency Core Cooling System (ECCS) [BJ][BM][BO] instrumentation for each Function in Table 3.3.5.1-1, Emergency Core Cooling System Instrumentation, to be Operable.

For Function 3d, High Pressure Coolant Injection (HPCI) System Condensate Header Level-Low, the applicable Modes are Mode 1 and Modes 2 and 3 when the reactor steam dome pressure is greater than 150 pounds per square inch gauge (psig). The number of required channels for Function 3d is one channel.

On July 20, 2013, at 0338 hours0.00391 days <br />0.0939 hours <br />5.588624e-4 weeks <br />1.28609e-4 months <br /> CDT, for the performance of surveillance procedure 1-SR-3.3.5.1.3(D), High Pressure Coolant Injection System Condensate Header Low Level Switch Calibration and Functional Test, both channels are booted; therefore, TS 3.3.5.1 Condition A was entered due to one or more channels inoperable. The TS 3.3.5.1 Required Action A.1 requires the entry of the Condition referenced in Table 3.3.5.1-1 for the channel to be entered immediately. The required Function for surveillance procedure 1-SR-3.3.5.1.3(D) was Function 3d which requires TS 3.3.5.1 Condition D to be entered. The TS 3.3.5.1 Required Action D.1 requires the HPCI System to be declared inoperable within one hour.

The TS 3.3.5.1 Required Action D.1 was not completed within the required one hour; therefore, TS 3.5.1 Condition C, HPCI System inoperable, was entered.

The LCO 3.5.1 requires each ECCS injection/spray subsystem and the Automatic Depressurization (ADS) [SB] function of six safety/relief valves [VM to be Operable in Mode 1 and Modes 2 and 3, except HPCI and ADS valves are not required to be Operable with reactor steam dome pressure less than or equal to 150 psig.

Condition C of TS 3.5.1 was entered due to TS 3.3.5.1 Required Action D.1 not being completed within the required one hour. Required Action C.1 of TS 3.5.1 requires that Reactor Core Isolation Cooling (RCIC) System [BN] to be verified Operable immediately and Required Action C.2 of TS 3.5.1 requires that the HPCI System to be restored to Operable status within 14 days.

The RCIC System was verified to be Operable immediately on July 20, 2013, at 0438 hours0.00507 days <br />0.122 hours <br />7.242063e-4 weeks <br />1.66659e-4 months <br /> CDT by Operations personnel. On July 20, 2013, at 0454 hours0.00525 days <br />0.126 hours <br />7.506614e-4 weeks <br />1.72747e-4 months <br /> CDT, Operations personnel declared HPCI System Operable and exited TS 3.3.5.1 Condition A, TS 3.3.5.1 Condition D, and TS 3.5.1 Condition C.

B. Status of structures, components, or systems that were inoperable at the start of the event and that contributed to the event

Surveillance procedure 1-SR-3.3.5.1.3(D) required that both channels associated with the HPCI System condensate header level switches [LS] be booted, which made these level switches inoperable. These level switches were required to be returned to Operable status within one hour before the HPCI System would be declared inoperable; therefore, the inoperable level switches contributed to the unplanned inoperability of the HPCI System.

C. Dates and approximate times of occurrences

July 20, 2013, at 0338 hours0.00391 days <br />0.0939 hours <br />5.588624e-4 weeks <br />1.28609e-4 months <br /> CDT July 20, 2013, at 0358 hours0.00414 days <br />0.0994 hours <br />5.919312e-4 weeks <br />1.36219e-4 months <br /> CDT July 20, 2013, at 0438 hours0.00507 days <br />0.122 hours <br />7.242063e-4 weeks <br />1.66659e-4 months <br /> CDT July 20, 2013, at 0454 hours0.00525 days <br />0.126 hours <br />7.506614e-4 weeks <br />1.72747e-4 months <br /> CDT July 20, 2013, at 1156 hours0.0134 days <br />0.321 hours <br />0.00191 weeks <br />4.39858e-4 months <br /> CDT Operations personnel entered TS 3.3.5.1 Condition A and TS 3.3.5.1 Condition D.

Operations personnel were notified by Maintenance personnel that there were issues with testing. Operations personnel decided to continue resolving issues and complete surveillance procedure 1-SR-3.3.5.1.3(D).

Operations personnel declared HPCI System inoperable in accordance with TS 3.3.5.1 Required Action D.1 and entered TS 3.5.1 Condition C.

Operations personnel declared HPCI Operable and exited TS 3.3.5.1 Condition A, TS 3.3.5.1 Condition D, and TS 3.5.1 Condition C.

The BFN reported the event to the NRC.

D. Manufacturer and model number (or other identification) of each component that failed during the event:

There was no failure of a component for this event.

E. Other systems or secondary functions affected

There were no other systems or secondary functions affected.

F. Method of discovery of each component or system failure or procedural error

During performance of surveillance procedure 1-SR-3.3.5.1.3(D), the HPCI System was declared inoperable due to exceeding the required Completion Time of TS 3.3.5.1 Required Action D.1.

G. The failure mode, mechanism, and effect of each failed component, if known:

There was no failure of a component. The problem was the failure to complete surveillance procedure 1-SR-3.3.5.1.3(D) within the required Completion Time of TS 3.3.5.1 Required Action D.1 which resulted in the unplanned HPCI System inoperability.

H. Operator actions

Operations personnel declared the HPCI System inoperable as required by TS 3.3.5.1 Required Action D.1, and entered TS 3.5.1 Condition C.

I. Automatically and manually initiated safety system responses

There were no automatically or manually initiated safety system responses.

I1l.

Cause of the event

A. The cause of each component or system failure or personnel error, if known:

Immediate Cause The immediate cause of this event was the failure to complete surveillance procedure 1-SR-3.3.5.1.3(D) within the required Completion Time of TS 3.3.5.1 Required Action D.1 which resulted in the unplanned HPCI System inoperability.

Root Cause The root cause of this event was determined to be the failure to declare the HPCI System inoperable as part of the planned surveillance testing on the HPCI System condensate header low level switches.

B. The cause(s) and circumstances for each human performance related root

cause

The root cause relates to surveillance procedure 1-SR-3.3.5.1.3(D). Based on guidance provided in NUREG-1022, Event Report Guidelines 10 CFR 50.72 and 50.73, planned entry into TS 3.5.1 Condition C, i.e. declaring the HPCI System inoperable, prior to performing surveillance procedure 1 -SR-3.3.5.1.3(D) would not have been reportable in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.72 or 10 CFR 50.73. However, surveillance procedure 1-SR-3.3.5.1.3(D) did not require entry into TS 3.5.1 Condition C prior to performing the steps of the surveillance procedure.

Surveillance procedure 1-SR-3.3.5.1.3(D) did not reflect conservative decision making, in that the procedure was developed based on the assumption that the performance of surveillance procedure 1-SR-3.3.5.1.3(D) would be successfully completed within the one hour time period allowed, in TS 3.3.5.1 Required Action D.1, prior to requiring the HPCI System to be declared inoperable. Performance of surveillance procedure 1-SR-3.3.5.1.3(D) takes approximately 45 minutes to complete, which does not leave much margin to the one hour TS 3.3.5.1 Completion Time if issues with implementing the surveillance procedure are encountered.

Surveillance procedure 1-SR-3.3.5.1.3(D) was developed by Tennessee Valley Authority (TVA) personnel. During the investigation of this event, no time or situation pressures associated with performance of the surveillance procedure were identified.

Surveillance procedure 1-SR-3.3.5.1.3(D) has been revised to declare the HPCI System inoperable at the beginning of this surveillance in order to prevent an unplanned HPCI System inoperability.

IV. Analysis of the event

The TVA is submitting this report in accordance with 10 CFR 50.73(a)(2)(v)(D), as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.

Surveillance procedure 1-SR-3.3.5.1.3(D) was originally scheduled to be performed by the evening shift Maintenance personnel on July 17, 2013. This test was rescheduled to be performed by the night shift Maintenance personnel on July 19, 2013. The Maintenance personnel assigned to perform surveillance procedure 1-SR-3.3.5.1.3(D) were inexperienced. One of the Maintenance personnel had never performed the test and the other Maintenance personnel had not performed the surveillance for several years. The TS 3.3.5.1 Required Action D.1 requires the HPCI System to be declared inoperable within one hour and this surveillance takes approximately 45 minutes to complete, provided everything goes as planned.

On July 20, 2013, at 0338 hours0.00391 days <br />0.0939 hours <br />5.588624e-4 weeks <br />1.28609e-4 months <br /> CDT, for the performance of surveillance procedure 1-SR-3.3.5.1.3(D), TS 3.3.5.1 Condition D was entered. When Maintenance personnel connected the test equipment to one of the switches, they began having difficulty obtaining the expected indications. Approximately 20 minutes into the entry of TS 3.3.5.1 Required Action D. 1, Maintenance personnel contacted Maintenance management because they were experiencing problems with the testing rig.

Maintenance management contacted Operations personnel to notify them of the issue.

Maintenance management and Operations personnel discussed the issue and decided to continue with the testing.

On July 20, 2013, at 0438 hours0.00507 days <br />0.122 hours <br />7.242063e-4 weeks <br />1.66659e-4 months <br /> CDT, Operations personnel declared the HPCI System inoperable in accordance with TS 3.3.5.1 Required Action D.1 since the HPCI System condensate header level switches were not restored to Operable status within the required one hour Completion Time. On July 20, 2013, at 0454 hours0.00525 days <br />0.126 hours <br />7.506614e-4 weeks <br />1.72747e-4 months <br /> CDT, Maintenance personnel notified Operations personnel that the performance of surveillance procedure 1-SR-3.3.5.1.3(D) was completed and Operations personnel declared the HPCI System and the associated instrumentation Operable.

V.

Assessment of Safety Consequences

The HPCI System consists of a steam turbine-driven system driving a constant-flow pump assembly to inject either Condensate Storage Tank [KA] water or Suppression Pool [BT] water into the reactor under emergency conditions. The HPCI System provides adequate core cooling for all break sizes which do not result in rapid

depressurization of the reactor vessel and functions independent of off-site power sources and Emergency Diesel Generators [EK].

Surveillance procedure 1-SR-3.3.5.1.3(D) calibrates and tests the performance of the HPCI System condensate header level switches. The function of these level switches is to provide an open signal to the flow control valves that transfers the HPCI System pump set suction from the condensate header to the Suppression Pool upon sensing a low condensate header level condition.

A. Availability of systems or components that could have performed the same function as the components and systems that failed during the event:

This event resulted in the HPCI System being inoperable; however it remained available to perform its safety function. The RCIC System and all other ECCS Systems remained Operable to maintain adequate core cooling during the period of HPCI System inoperability.

B. For events that occurred when the reactor was shut down, availability of systems or components needed to shutdown the reactor and maintain safe shutdown conditions, remove residual heat, control the release of radioactive material, or mitigate the consequences of an accident:

The BFN, Unit 1, was not shut down during this event.

C. For failure that rendered a train of a safety system inoperable, an estimate of the elapsed time from discovery of the failure until the train was returned to service:

The problem was the failure to complete surveillance procedure 1-SR-3.3.5.1.3(D) within the required Completion Time of TS 3.3.5.1 Required Action D.1 which resulted in an unplanned HPCI inoperability. The HPCI System was declared inoperable on July 20, 2013, at 0438 hours0.00507 days <br />0.122 hours <br />7.242063e-4 weeks <br />1.66659e-4 months <br /> CDT, and returned to Operable status 16 minutes later at 0454 hours0.00525 days <br />0.126 hours <br />7.506614e-4 weeks <br />1.72747e-4 months <br /> CDT.

VI.

Corrective Actions

Corrective Actions are being managed by TVA's corrective action program under Problem Evaluation Report (PER) 756603.

Immediate Corrective Actions

Surveillance procedure 1-SR-3.3.5.1.3(D) was completed satisfactorily and the HPCI System and the associated instrumentation were declared Operable.

Corrective Actions to Prevent Recurrence or to Reduce Probability of Similar Events Occurinq in the Future Surveillance procedures "High Pressure Coolant Injection System Condensate Header Low Level Switch Calibration and Functional Test" (1-SR-3.3.5.1.3(D),

2-SR-3.3.5.1.3(D), and 3-SR-3.3.5.1.3(D)) and "HPCI Suppression Chamber High Level Calibration and Functional Test" (1-SR-3.3.5.1.3(E), 2-SR-3.3.5.1.3(E), and

3-SR-3.3.5.1.3(E)) were revised to require the HPCI System be declared inoperable prior to the performance of these surveillance procedures.

VII.

Additional Information

A. Previous similar events at the same plant:

A search of BFN Licensee Event Reports for Units 1, 2, and 3 for the last five years did not identify any similar events.

A search was performed on the BFN corrective action program. There were no similar corrective action program documents that were similar to this event.

B. Additional Information

There is no additional information.

C. Safety System Functional Failure Consideration:

The function of the Suppression Pool High Level instrumentation to automatically switch the HPCI System suction source from the Condensate Storage Tank to the Suppression Pool on high Suppression Pool level was not affected during the performance of surveillance procedure 1-SR-3.3.5.1.3(D), nor was the ability to manually transfer suction sources either locally or remotely from the Control Room.

Based on design calculations for the HPCI System, the automatic suction switchover on high Suppression Pool level will occur before the low Condensate Storage Tank level is reached; therefore, the HPCI System remained available throughout the event.

In accordance with Nuclear Energy Institute 99-02, this event is not considered a safety system functional failure due to the availability of the HPCI System during this event.

D. Scram with Complications Consideration:

This event did not result in an unplanned scram with complications.

VIII. COMMITMENTS

There are no commitments.