ML18039A812

LER 99-005-00:on 990617,ESF Actuation & HPCI Declared Inoperable.Caused by Personnel Error.Reset HPCI & Returned Sys to Operable Status with 25 Minutes.With 990712 Ltr

ML18039A812
Person / Time
Site:	Browns Ferry
Issue date:	07/12/1999
From:	Herron J, Moody G TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-99-005, LER-99-5, NUDOCS 9907190071
Download: ML18039A812 (20)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RZDS)

ACCESSZOH NBR:9907190071 DOC.DATE: 99/07/12 NOTARIZED: NO DOCKET FACIL:50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME AUTHOR AFFILIATION MOODY,G.F. Tennessee Valley Authority HERRON,J.T. "

Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 99-005-00:on 990617,ESF actuation c HPCI declared inoperable. Caused by personnel error.HPCZ reset &. sys returned to operable status with 25 minutes.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL LPD2-2 PD 1 1 LONG,W 1 1 INTERNAL: ACRS 1 1 E ENTE 1 1 NRR/DIPM/IOLB 1 1 NRR/DRIP/REXB 1' ERR/DSSA/SPLB 1 1 RES/DET/ERAB 1 1 RES/DRAA/OERAB 1 ~ 1 RGN2 ,FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LMZTCO MARSHALL 1 1 NOAC POORE,W. 1 1 NOAC QUEENER,DS NRC PDR 1 1 NUDOCS FULL TXT '1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LIS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTE DESK (DCD) ON EXTENSION 415-2083 FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 16 ENCL 16

II ~I Tennessee Valfey Authority. Post Office Box 2000, Decatur, Atabarna 36609 July 12, 1999

'U.S. Nuclear Regulatory Commission 10 .CFR 50. 73 ATTN: Document Control Desk Washington, D.. C. 20555

Dear Sir:

TENNESSEE VALLEY AUTHORITY BROWNS, FERRY NUCLEAR PLANT (BFN)

UNIT 2' DOCKET 50-260 FACILITY OPERATING LICENSE DPR 52 LICENSEE EVENT REPORT. (LER) 50-260/1999-005-000

. The enclosed report provides detai;ls concerning an Engineered Safety Feature Actuation and the Unit 2 High Pressure Coolant Injection syst;em being declared inoperable due to personnel error during surveillance testing.

TVA i: s reporting this event pursuant to 10CFR50.73(a)(2)(iv) as an event or condit;ion,that resulted in an automatic actuation of an Engineered Safety Feature and 10CFR50.73(a),(2,)-(v) as a condition that alone could have prevented the fulfillment of the safety. function of a structure or system needed to mitigate, the consequences of an acci'dent.

Sincerely, J hn T. Herron In crim Site Vice President See page 2 9907i9007i 990712 PDR ADOCK OS000260 8 PDR

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U.S. Nuclear Regulatory Commission Page 2 July 12, 1999 Enclosure cc (Enclosure):

Mr. William O. Long, Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. Paul E. Fredrickson, Branch Chief U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth Street, SW, Suite .23T85 Atlanta, Georgia 30303-3415 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611

I!

I

NRC FORIVI 366

'0 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXFIRES oersonoot

{6-1998) Estimated burden per response to comp)y with this mandatory information collection request: 50 hrs. Reported lessons learned are Incorporated into the licensing process and,fed back to industry. Forward comments regarding LICENSEE EVENT'REPORT (LER) burden estimate to the Records Marogernent Branch (TA F33), U.S. Nuclear Regulatory Commission, Washington. DC 20555400( and to the Paperwork

~

(See reverse for required number of Reduction Project (31500)04), Office of Management and Budget.

Washington, DC 20503. If an information collection does not display a digits/characters for each block) currently valid OMB control number, the NRC may not conduct or sponsor.

and a person is not required to respond to. the Informatkxl cot(ection.

FACIUTY NAME (I) DOCKET NUMBER (2) PAOE IS)

Browns Ferry Nuclear Plant Unit.2 05000260 1of7 TITLE (4)

Engineered Safety Feature (ESF) Actuation and High Pressure Coolant Injection (HPCI) Inoperable Due To Personnel Error.

During Surveillance Testing "EVENT DATE {5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR SEQUENTIAL 'EVISION MONTH DAY FACIUTY NAME DOCKET NUMBER NUMBER NUMBER NA DOCKET NUMBER 06 17 1999 1999 005 000 07 '12 1999 NA OPERATING THIS REPORT IS SUBMITTED PURSUA NT To-THE REQUIREMENTS OF 10 CFR II: (Check ono or more)

MODE (9) 20.2201 {b) 20.2203(a)(2)(v) 50.73(a) (2) (i) 50.73(a) (2)(viii

)

POWER 20.2203(a)(1) 20.2203(a)(3) (i) 50.73(a)(2)(iil 50.73(a)(2){x)

LEVEL (10) ,1 00 20.2203(a) (2)(i) 20.2203(a)(3)(ii) 50.73(a) (2) (iii) '3.71 20.2203(a)(2){ii) 20.2203(a) (4) X 50.73(a)(2)(iv) OTHER 20.2203(a) (2) (iii) 50.36(c) (1) X 50.73(a)(2)(v) Specify in Abstract below or ln NRC Form 366A 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a) (2) (vii)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Include Area Code)

• Gerald F. Moody; Licensing Project Manager 256-729-7534 COMPLETE ONE LINE FOR EACH. COMPONENT FAILURE DESCRIBED IN THIS REPORT {13)

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE NPRDS TO NPRDS SUPPLEMENTAL REPORT EXPECTED {14) EXPECTED MONTH, OAY YES X NO SUBNIISSION (If yes, complete EXPECTED SUBMISSION DATE) DATE (15) YEAR'BSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) {16)

On June 17, 1999, at approximately 1337 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.087285e-4 months <br /> Central daylight Time.(CDT) during the performance of a regularly scheduled surveillance on a Unit 2 Core and Containment Cooling System Analog Trip Unit (ATU), an unexpected isolation of the HPCI System occurred. The HPCI system was immediately declared inoperable. Upon investigation, it was determined that the isolation was due to personnel error. Specifically, contact inhibits (boots) were incorrectly placed on a relay during the, surveillance. Section 7.15 of this procedure was being performed which is used to demonstrate operability of the HPCI isolation function on high steam line flow. The inhibits were removed, the HPCI isolation was reset and the system was returned to operable status. During this event, HPCI was inoperable less than 1/2 hour of the 14 days allowed by the Technical Specification LCO. Also, during the period the HPCI system was inoperable, all other required alternate safety systems were operable and would have performed their design function if called upon. Accordingly, there was no significant reduction in the degree of protection provided to public health and safety. Furthermore, the safety of the plant, its personnel, and the public was not compromised.

r This report is submitted pursuant to 10 CFR 50.73 (a) (2) (iv) as an event or condition that resulted in an automatic actuation of an engineered safety feature (ESF) and 10CFR50.73(a)(2)(v) as a condition that alone could have prevented the fulfillment of the safety function of a structure or system needed to mitigate the consequences of an accident.

NRC FORM 366B {6-199BI

0 0 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION IS-ISSSI LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 1 DOCKET LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION NUMBER 2 of 7 Browns Ferry Nuclear Plant - Unit 2 05000260 1999 005 000 TEXT (lf more space is required, use additional copies of'NRC Form 366Ai I17l I. PLANT CONDITION(S)

At the time of the event, Unit 2 was in mode 1 at 100 percent pow'er, approximately 3456 megawatts

'thermal. Unit 3 was in mode 1 at 100 percent power, approximately 3456 megawatts thermal. Unit 1 was shutdown and defueled.

II. DESCRIPTION OF EVENT A. Event:

On June 17, 1999, at approximately 1217 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.630685e-4 months <br /> Central Daylight Time (CDT) surveillance test Core and Containment Cooling Systems Analog Trip Unit (2-SR-3.3.5.1.2 (ATU C)) was started.

Section 7.15 of this procedure was being performed which is used to demonstrate operability of the HPCl.isolation function on high steam line flow. At approximately 1337 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.087285e-4 months <br /> CDT, the Unit 2 control room operators observed the High Pressure Coolant Injection (HPCI) [BJj system inboard and outboard containment isolation valves closing which was contrary to the SR requirement. The surveillance was stopped and HPCI was declared inoperable. As required by Technical Specifications, Browns Ferry Unit 2 entered a fourteen day Limiting Condition for Operation (LCO) for an inoperable HPCI.system.

At 1340 hours0.0155 days <br />0.372 hours <br />0.00222 weeks <br />5.0987e-4 months <br /> it was determined that the HPCI isolation had been caused by the craftsmen (utility, non-licensed) performing this surveillance inhibiting the wrong contacts on a relay. At 1345 hours0.0156 days <br />0.374 hours <br />0.00222 weeks <br />5.117725e-4 months <br />, Operations personnel directed the craftsmen to remove the trip signal in order to de-energize

'the relay so that the HPCI isolation could be reset. This was done and the contact inhibits were removed. The HPCI isolation was reset, the surveillance was satisfactorily completed without further incident, and the system was returned to an operable status at approximately 1402 hours0.0162 days <br />0.389 hours <br />0.00232 weeks <br />5.33461e-4 months <br /> CDT.

.This report is being submitted pursuant to.10CFR 50.73 (a) (2) (iv) as an event or condition that resulted in an automatic actuation of an engineered safety feature (ESF) and 10CFR50.73(a)(2)(v) as a condition that alone could have prevented the fulfillment of the safety function of a structure or system needed to mitigate the consequences of an accident.

B. Ino erable Structures Com onents or S stems that Contributed to the Event:

None.

C. Dates and A roximate Times of Ma or Occurrences:

June 17, 1999, 1217 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.630685e-4 months <br /> CDT Surveillance 2-SR-3.3.5.1.2 (ATU C) Core and Containment Cooling Systems Analog Trip Unit Functional Test Started.

June 17, 1999, 1337 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.087285e-4 months <br /> CDT HPCI isolation occurred due to improper contacts being booted and HPCI was declared inoperable.

NRC FORM 366B I6-1998)

ll 4l NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION I6-1998)

LICENSEE EVENT REPORT (LER).

TEXT CONTINUATION FACILITY NAME 1 DOCKET LER NUMBER 6 PAGE I3 YEAR SEQUENTIAL REVISION NUMBER 3of7 Browns Ferry Nuclear Rant - Unit 2 05000260 1999 005 - 000 TEXT illmore space is required, use additional copies of hfRC Form 366Ai I17I June 17, 1999, 1402 hours0.0162 days <br />0.389 hours <br />0.00232 weeks <br />5.33461e-4 months <br /> CDT The isolation was reset and HPCI was returned to an operable status.

June 17, 1999, 1627 hours0.0188 days <br />0.452 hours <br />0.00269 weeks <br />6.190735e-4 months <br /> CDT A 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Non-Emergency notification was made to the NRC in accordance with 10 CFR 50.72 (b) (2) (ii) and 10 CFR 50.72 (b) (2) (iii).

D. Other S stems or Seconda Functions Affected None.

E. Method. of Discove During the performance of the surveillance,'Unit 2 Control Room Operators noticed the HPCI inboard and outboard isolation.valves closing.

F. 0 erator Actions No operator actions contributed to this event.

G. Safet S stem Res onses Safety system response was as. expected under the circumstances described in this report.

III. CAUSE OF THE EVENT A. Immediate Cause The immediate cause of this event was personnel error (installing the inhibit boots on the wrong contacts).

B. Root Cause The craftsmen (utility, non-lichnsed) involved in performing this surveillance installed the relay contact inhibits on the incorrect contacts. This was due in partto their familiarity with the test which led,them to rely on, memory in order to determine the placement of the contact inhibits instead of illustrations provided in the surveillance procedure.

C. Contributin Factors It was determined that the surveillance procedure could have'been more clearly written due to the fact that it allowed craftsmen to reference the illustration "as necessary" to determine proper placement of the contact inhibits. In addition, the numbering scheme used in the illustration may have contributed to the confusion.

NRC FORM'366 I6-1996)

II NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6. I 998)

LICENSEE:EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME'(1 DOCKET LER NUMBER 6 PAGE (3 YEAR SEQUENTIAL REVISION NUMBER 4o(7 Browne Ferry NUclear Plant - Unit 05000260 2'EXT 1999 005 000 (If moro space is required, use additional copies of PiRC Form 366A J (17)

IV. ANALYSIS OF THE EVENT

. Instrument Maintenance Craftsmen (utility, non-licensed) performing this surveillance relied on memory instead'of available resources to identify the relay contacts to be inhibited. On this type of relay (General Electric Company type HFA) [RLY] (see Figure on page 7) the contact positions are numbered from left to right when facing the relay from the front of the panel. where the craftsmen were working. The craftsmen performing the test inappropriately. counted the positions from right to left and installed the inhibits on the two left most set of contacts instead of the two right most set of contacts. The surveillance procedure contained an HFA relay illustration showing the relay layout. The appropriate relay contacts to be inhibited were illustrated. The craftsmen performing the surveillance did not refer to the illustration to ensure the correct contacts were inhibited. Because the craftsmen were familiar with the test, they relied on memory to determine which contacts to inhibit rather than use the illustration. This surveillance is a quarterly test that has been performed numerous times without incident. The fact that the surveillance steps included the HFA relay contact position numbers in addition to the actual contact numbers (which are numbered in the reverse sequence from the "position" numbers-see attached figure labeled HFA relay for clarification) and that the action steps directed the personnel performing the test to refer to the illustration "as necessary" was found to be a contributing factor.

V. ASSESSMENT OF THE SAFETY CONSEQUENCES The HPCI system is provided to assure that the reactor is adequately cooled to limit fuel cladding temperature in the event of a small pipe break in the nuclear system and loss of coolant which does not result in rapid depressurization of the reactor vessel. The HPCI system permits the nuclear plant to be shut down, while maintaining sufficient reactor vessel water inventory until the reactor vessel is depressurized. The HPCI system continues to operate until the reactor vessel is below the pressure at which Low Pressure Coolant Injection (LPCI) [BO] operation or Core Spiay (CS) [SM] operation maintains core cooling.'In the event HPCl,is not available or not sufficient to maintain reactor water level, the Automatic Depressurization System (ADS) [SB] functions to reduce reactor pressure so that flow from the LPCI and CS enters the reactor vessel in time to cool the core and limit fuel cladding temperature.

BFN Technical Specifications allow continued reactor operation for up to 14 days if HPCI is inoperable, provided ADS, CS, LPCI, and Reactor Core Isolation Cooling (RCIC) [BN] systems are operable. RCIC provides an alternate supply of high pressure makeup while ADS would depressurize the reactor to allow CS and LPCI to provide adequate low pressure ECCS makeup'o the reactor. The availability of these redundant and diversified systems provides adequate assurance of core cooling while the HPCI system is inoperable. For this event, HPCI was inoperable. less than 1I2 hour of the 14 days allowed by the LCO. During the period the HPCI system was inoperable, these required systems were operable and it is expected they would have performed their design function if called upon.

Accordingly, there was no significant reduction in the degree of protection provided tq public health and safety. Furthermore, the safety of the plant, its personnel, and the public was not compromised.

NRC FORM '366 (6-1998)

t 4l

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 1 DOCKET LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION NUMBER 5 or 7 Browne Ferry Nuclear Plant - Unit 2 05000260 1999 - 005 000 TEXT fffmore space is required, use additional copies of NRC Form 366A/ I 17)

VI. CORRECTIVE ACTIONS A. Immediate Corrective Actions The HPCI isolation was detected immediately and the cause of the isolation was determined within 3 minutes of the isolation. Actions were immediately initiated to return the system to standby readiness. The HPCI isolation was reset and the system was returned to operable status within 25 minutes.

B. Corrective Actions to Prevent Recurrence Information concerning this incident was communicated to plant personnel through stand down briefings.

I Craftsmen involved in the performance of this surveillance will receive personnel corrective action in accordance with TVA policy.

instructions are being reviewed to enhance guidance (where warranted) for

'urveillance individuals performing these tests.

'II

~ ADDITIONALINFORMATION A. Failed Com onents:

None.

B. Previous LERs on Similar Even'ts:

review of previous events for the past two years revealed one LER that was the result of an unplanned Engineered Safety Feature Actuation due to improperly'placed jumpers or contact inhibits.

LER 260/1997-005-000 was written to document an unexpected Engineered Safety Feature Actuation caused by personnel closing the wrong relay during a surveillance test. This action was inadvertent and the corrective actions for this event did not address a failure to follow work instructions. Accordingly, the corrective actions taken would not have precluded this event.

'VAdoes not consider these corrective actions regulatory commitments. The completion of these items will be tracked in TVA's Corrective Action Program.

NRC FORM 366 I6-1996)

II II NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6. I 998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME 1 DOCKET LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION NUMBER 6 ol7 Browns Feiry NUclear Plant - Unit 2 05000260 1999 005 - 000 TEXT (lf more space is required, use additional copies of NRC Form 366A J I17)

C. Additional.Information:

None.

D. Safet S stem Functional Failure:

This event does not meet the criteria for a safety system functional failure as described in NEI 99-02 because it was immediately recognized that the HPCI system was inoperable.

The condition was not caused by an equipment failure and the isolation was reset within 25 minutes.

Vill. COMMITMENTS None.

NRC FORM 366 I6-199BI

0

NRC FORIVI 366A U.S.

I6.1998) NUCLEAR'REGULATORY'COMMISSION'ACILITY LICENSEE EVENT REPORT (LER).

TEXT CONTINUATION NAME 1 DOCKET LER NUIVIBER 6 PAGE 3)

YEAR SEQUENTIAl REVISION,

'NUMBER .7of7 Browns Ferry Nuclear Plant - Unit,2 05000260 1999 005 - 000 TEXT'fifmore space is required, use addi rionai copies of hfRC Form 366AJ f17)

.FIGURE HFA RELAY Contacts 3-4 Contacts 1-2 (Contact position 5) (Contact position 6) 0 '"'i::

F:

NRC FORM 366 f6-1998)

'li',