ML18038B966

LER 97-005-00:on 970824,LCO Was Not Entered When Valve Was Malfunctioning.Caused by Lack of Questioning Attitude by Operations Crew.Involved SROs Were Counseled & Problem Evaluation Rept Will Be Discussed

ML18038B966
Person / Time
Site:	Browns Ferry
Issue date:	10/03/1997
From:	Jay Wallace TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18038B965	List: ML18038B964 ML18038B966
References
LER-97-005-02, LER-97-5-2, NUDOCS 9710100204
Download: ML18038B966 (16)

Text

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSiON APPROVED BY OMB No. 31504)104 (4-95) EXPIRES 04/30/98 ESllMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORYINFORMATION COLLECllON REQUEST:

LICENSEE EVENT REPORT (LER) 500 HRS. REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE UCENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING (See reverse for required number of BURDEN ESTTMATE TO THE INFORMATIONAND RECORDS digitslcharacters for each block) MANAGEMENT BRANCH rrA F33), UA. NUCLEAR REGUlATORY COMMISSION, WASHINGTON, DC 205554)001, FACIUTY NAME II) DocKET NUMBER IT) Ia)

Browns Ferry Nuclear Plant (BFN) Unit 3 05000296'ADEOF 8 1 TITLE H)

When a valve was malfunctioning, an LCO was not entered. The root cause for this event was that Operations crew acked a questioning attitude and,mindset. This LCO oversight is.prohibited'by technical specifications.

EVENT DATE 5) LER NUMBER 6 REPORT DATE (7) OTHER FACILITIES INVOLVED 6 FACIUTY NAMF SEQUENBAL REVISION MONTH DAY YEAR MONTH DAY YEAR NUMBER NUMBER NIA FACIUTY NAMF 8 24 97 97 10 97 03 OPERATING THIS REPORT IS SUBMITTED PURSUANT To THE REQUIREMENTS OF 10 CFR: (Chock ono or moro 11 MODE (9) N 20.2201(b) 20.2203(a)(2)(v) X 50.73(a)(2)(I) B 50.73(a) 20,2203(a)(1) 20.2203(a)(3)(l) 50.73(a)(2)(ii) 50.73(a)

POWER LEVEL (10) 100 20.2203(a)(2)(l) 20.2203(a)(3)(ii) 50.73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50.73(a)(2)(lv) OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(v) s in 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vi)) below or In UCENSEE CONTACT FOR THIS LER (12)

TElEPHONE NUMBER (Iaerude Area Code)

James E. Wallace, Ucensing Engineer (205) 729-7874 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 CAUSE SYSTEM COMPONENT'ANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE To NPRDS To NPRDS X VA FSV A610 SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED YEs SUBMISSION, (lf yes, complete EXPECTED SUBMISSION DATE).

X NO DATE (15)

ABSTRACT (Limit to 1400 spaces, l.e., approximately 15 slnple-spaced typewritten lines) (16)

On August 24, 1997, at 1945 hours0.0225 days <br />0.54 hours <br />0.00322 weeks <br />7.400725e-4 months <br />, Units 2 and 3 were approximately 100 and 96 percent power, respectively. Unit 1 was defueled. At that time, a primary containment isolation valve failed to close. Although a relay in its circuit was replaced five (5) days earlier, the replacement did not resolve the valve problem. Specifically, during the performance of a surveillance instruction (Sl) for testing the containment atmosphere dilution system valve operability, the primary containment isolation flow control valve failed to close. However, the limiting condition for operation (LCO) was not entered as required by the plant's technical specifications (TS). On September 5, 1997, after a review of these events, it was determined that an LCO should have been entered. The root cause for not entering an LCO was that the Operations crew lacked a questioning attitude; Senior Reactor Operators developed a mindset regarding the failure mechanism and did not fully assess new information for the effect on technical specifications. The immediate corrective actions included replacement of the solenoid valve. Corrective actions to preclude recurrence include the counseling of the involved Senior Reactor Operators. This report is submitted in accordance with 10 CFR 50.73 (a}(2)(i)(B) as any operation or condition prohibited by the plant's technical specifications. No previous LERs were identified where BFN personnel failed to enter an LCO.

97iOi00204 97i003 PDR ADGCK 05000296 S PDR

Ik Cl NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY DOCKET LER NIMBER NUMBER NUMBER Browns Ferry Unit 3 05000296 2 of 8 97 -- 005 -- 00 T XT more space is requir ~ use a iuona copies o orm (17)

PLANT CONDZTZONS At the time of the discovery of the condition, Unit 2 and Unit 3 were approximately 100 and 96 percent power, respectively. Unit 1 was shutdown and defueled.

ZZ. DESCRZPTZON OF EVENT Event On August 24, 1997, at 1945 hours0.0225 days <br />0.54 hours <br />0.00322 weeks <br />7.400725e-4 months <br />, Central Daylight Time, one of Unit 3 primary containment isolation flow control valve (PCIFCV)

(3-FCV-64-34) [FCV] [VA] on the suppression pool ventilation line

-(See Figure 1) to the reactor building ventilation exhaust/standby gas treatment'system failed to close even though a relay (3-86 34) in its circuit was replaced five (5) days earlier (See simplified control logic on Figure 2). The relay replacement did not resolve a problem with the malfunctioning PCIFCV.

Consequently, during the performance of the surveillance instruction (SI) for testing the containment atmosphere dilution system valve operability, the PCIFCV failed to close within the time frame specified in the SI acceptance criteria. At, that time, a Senior Reactor Operator (SRO) (Utility, licensed) made a cognitive error by failing to recognize the true nature of the event in that the plant did not enter a Limiting Condition for Operation (LCO) as required by the plant's technical specifications (TS) s.

On July 26, 1997 at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br />, the PCIFCV failed to close on its first attempt. After troubleshooting, the handswitch was cycled several times, and the valve eventually closed. Based on field investigations, it was concluded that this failure did not affect the PCIS function of the PCIFCV. A Work request (WR 385493) was initiated to troubleshoot relay contacts which may not have opened as required. Operations decided that the PCIFCV was to be cycled every four hours until the WR was completed. On July 29, 1997, a Technical Operability Evaluation (TOE) was performed. The TOE documented that PCIFCV's PCIS function was not affected by a malfunction of the relay. The TOE recommended that the control relay [RLY] be replaced as soon as the schedule allowed (This WR could not be immediately implemented because a design change notice w'as required to replace the relay due to obsolete parts.

Additionally, it was a high risk activity). In addition, the TOE recommended that the need to cycle of the valve every four (4) hours was no longer required. On August 14, 1997, at 2305 hours0.0267 days <br />0.64 hours <br />0.00381 weeks <br />8.770525e-4 months <br />, the isolation PCIFCV failed to close when venting the drywell.

After the handswitch was cycled several times, the valve closed.

On six additional attempts, the valve closed within the SI time requirement. Based on the venting problem, a decision was made to NRC FORM 366A (445)

~ .

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME DOCKET LER NUMBER NUMBER NUMBER Browns Ferry Unit 3 05000296 3 of 8 97 .005 -- 00 TEXT ( moro space is reqinr, use a rriona copies o orm (17I resume cycling the valve every four. hours. On August 15r 1997r at 0912 hours0.0106 days <br />0.253 hours <br />0.00151 weeks <br />3.47016e-4 months <br />, the Shift Manager, a SRO, (Utility, Licensed) was informed to discontinue the cycling of the valve. On August 19, 1997, at 1119 hours0.013 days <br />0.311 hours <br />0.00185 weeks <br />4.257795e-4 months <br />, the work order to replace the relay was completed.

AUGUST 24 1997 On August 24, 1997, at 1945 hours0.0225 days <br />0.54 hours <br />0.00322 weeks <br />7.400725e-4 months <br />, TVA performed surveillance instruction SI-4.7.G.a-1 for testing the containment atmosphere dilution system valve operability. Again, the PCIFCV failed to close on the first attempt. The handswitch and valve was cycled two more times, and the PCIFCV closed each time. Four-hour cycling of the PCIFCV was resumed. In a telephone conversation, an Engineer representative (Utility, Non-licensed) reassured the Shift Manager that the TOE still applied (no PCIS operability concern).

The SI was completed with a noted test discrepancy; namely, the PCIFCV did not close as required. On August 28, 1997, 1255 hours0.0145 days <br />0.349 hours <br />0.00208 weeks <br />4.775275e-4 months <br />, the 'PCIFCV was cycled and declared inoperable due to a slow closure time. The solenoid valve was subsequently found sticking.. A four-hour Limiting Condition for Operation (LCO) 3.7.D.2 was entered to repair or isolate the affected line using an operable upstream valve in the deactivated position. The, PCIFCV. solenoid valve [SOL) was deenergized. The solenoi:d valve was replaced, and the PCIFCV was satisfactorily tested. At 1515 hours0.0175 days <br />0.421 hours <br />0.0025 weeks <br />5.764575e-4 months <br />, the PCIFCV was declared

.operable and'he LCO was exited.

The failure to enter the LCO existed for 3 days, 19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br />, and 30 minutes, from August 24, 1997, at 1945 hours0.0225 days <br />0.54 hours <br />0.00322 weeks <br />7.400725e-4 months <br /> until A'ugust 28, 1997, at 1515 hours0.0175 days <br />0.421 hours <br />0.0025 weeks <br />5.764575e-4 months <br />. At that time, further review of the series of PCIFCV failures in this event revealed a need to document a licensee reportable event determination (LRED) for failure to implement LCO actions required by Technical Specification 3.7.D.2 on August 24, 1997, at 1945 hours0.0225 days <br />0.54 hours <br />0.00322 weeks <br />7.400725e-4 months <br />..

Therefore, this report is submitted in accordance with 10 CFR 50.73 (a)(2)(i)(B) as any operation or condition prohibited by the plant's technical specifications'.

Ino erable Structures Co onents or S stems that Contributed to the Event:

American .Switch Company (ASCO) is the manufacturer of the solenoid.

valve. This valve was model number 206380-7F.

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

July 26, 1997 During an SI, the PCIFCV failed to at 1000 Hours CDT close on its first attempt. Four-NRC FORM 366A (4 95)

Ik 0 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION PACZLZTX NAME DOCKET LER NUMBER NUMBER NUMBER Browns Ferry Unit 3 05000296 4 of 8 97 -- 005 -- 00 TEXT ( more space is requir, rise a <<iona copies o orm,(17I hour cycling of the valve began.

July 29, 1997 TOE was subsequently prepared, and at 0859 Hours CDT concluded that PCIFCV's PCIS function not affected.

August 14, 1997 The PCIFCV failed again to close at 2305 Hours CDT when venting drywell. WR to replace the control relay was written. WR was delayed. This was a high risk activity.

August 19, 1997 Control relay was replaced, and at 1119 Hours CDT .PCIFCV was successfully tested.

August 24, 1997 The PCIFCV failed to close again on at 1945 hours0.0225 days <br />0.54 hours <br />0.00322 weeks <br />7.400725e-4 months <br /> CDT its first attempt.

August 28, 1997 Operations cycled the PCIFCV.

at 1225 Hours CDT Closure time was greater than allowed. Valve declared inoperable and LCO entered. Solenoid valve was identified as sticking. Solenoid valve was replaced, tested and declared operable.

September 5, 1997 After a review of the PCIFCV at 1223 Hours CDT failures in this event, an LRED was written for failure to implement the LCO remedial actions.

D. Other S stems or Seconda Functions Affected:

None.

Method of Discove BFN management reviewed the circumstances of the PCIFCV failures and concluded that the SROs should have entered an LCO.

erator Actions:

Operator actions are described in Section II.A, above.

G.. Safet S stem Res onses:

None.

NRC FORM 366A (~

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME DOCKET NUMBER NUMBER Browns Ferry .Unit 3 05000296 5 of 8 97 005 00 TEXT moro space <s roqu<r, uso a <<<o<<a cop<os o orm (17)

CAUSE OF THE EVENT A. Immediate Cause:

The immediate cause of the condition was that the SROs did not correctly determine that an LCO should be entered when the PCIFCV failed on its first attempt on August 24, 1997 at 1945 hours.

B. Root Cause:

The root cause of this event was that the Operations crew lacked a questioning attitude. SROs developed a mindset regarding the failure mechanism and did not fully assess new information for the effect on technical speci'fications.

C. CONTRIBUTING FACTOR There were four contributing factors to this event:

(1) A mind set was established- that the valve's PCIS function was not affected based on an evaluation and consultation with System Engineering.

(2) inadequate troubleshooting and diagnosis of problem which provided an incorrect assumption on which the evaluation was based.

(3) 'A presumption .that successful four-hour cycling of the valve ensured operability.

(4) Management did not adequately monitor, assess, and intervene in a timely manner.

IV. ANALYSIS OF THE EVENT The inboard and outboard isolation valves are redundant for primary containment purposes. For the events described in this LER, the outboard isolation valve was operable and would have mitigated the radiological impact of a design basis accident, if required.

Although the SROs did not enter the LCO condition at the proper time, no plant conditions were identified that would have resulted in the release of radioactive material, nor would any release of radioactive material release have happened had a design basis accident occurred.

Therefore, this event did'ot adversely affect plant personnel, or the public.

NRC FORM 366A (4.95)

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NRC FORM 366A, U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME I DOCKET NUMBER NUMBER Browns Ferry Unit 3 05000296 6 of 8 97 -- 005 -- 00 TEX mora space is requir ~ usa e ruona copies o oim (1 I CORRECTZVE ACTZONS A. Zrmnediate Corrective Actions:

None.

B. Corrective Actions to Prevent Recurrence:

The involved SROs were counseled. This action was completed on September 15, 1997.

The details of the problem evaluation report (PER) associated with, this LER will be discussed during Operator requalification ~

training.'ystem Engineers will be briefed on the details of the associated PER.1 Training will be conducted to sensitize Operations SROs on LCO entries and, methodology during troubleshooting activities for TS or other safety-related equipment.'

management review of this PER, it's ramifications and how meticulous management oversight, could have prevented this event will be discussed at the Management Review Committee.'Z'.

ADDITIONAL INFORMATION A. Failed Co onents:

American Switch Company (ASCO) is the, manufacturer of the solenoid valve. This valve was model number 206380-7F.

B. Previous LERs on Similar Events:

No previous LER were written for a failure to enter an LCO.

VZI. COhkfIGRENTS None.

Energy Industry Identification System (EIIS) system and component codes are identified in the text with brackets (e.g., [XX)).

1. These actions are being tracked by TVA's corrective action program and are not considered regulatory commitments, NRC FORM 366A (445),

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