Text

LER 93-016-01:on 930503,TS Violations Occurred Due to Circuitry for SG Power Operated Relief Valves & Post Accident Monitoring Instruments Being Inoperable.Replaced Missing Screws from Unit 1 QDPS.W/930715 Ltr
	ML20045J028
Person / Time
Site:	South Texas
Issue date:	07/15/1993
From:	Groth J, Pinzon J; HOUSTON LIGHTING & POWER CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
	LER-93-016, LER-93-16, ST-HL-AE-4506, NUDOCS 9307220320
	Download: ML20045J028 (8)
	v • d • e

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. The Light c o mp ;a n y gp South Texas Project Electric Generating P. O.Station Box 289 Wadsworth, Texas 77483 July 15, 1993 ST-HL-AE-4506 File No.: G26 10CFR50.73 U. S. Nuclear Regulatory Commission Attention: Document Control Desk ,

Washington, DC 20555 South Texas Project Unit 1 Docket No. STN 50-498 )

Revision 1 to Licensee Event Report 93-016 ;

Technical Specifications Violation Due to ;

Circuitry for the Steam Generator Power Operated Relief Valves and Post Accident Monitorina Instruments Beina Inocerable Pursuant to 10CFR50.73, Houston Lighting & Power (HL&P) l submits the attached revision to Unit 1 Licensee Event Report l 93-016 regarding a Technical Specifications violation due to circuity for the Steam Generator Power Operated Relief Valves and Post Accident Monitoring Instruments being technically inoperable for time periods that exceeded their allowed outage times. This event did not have an adverse effect on the health and safety of the public.

This revision provides the final results of the analysis of I the event. The results demonstrate that even if'a seismic event l had occurred, both Units 1 and 2 would have been able to safely shut down. Changes are indicated by revision bars.

The expected submission date for this revision was originally l projected as July 1, 1993. In a telephone conversation on July 1, 1993, with Mr. W. Johnson of NRC Region IV, the submission date was extended to July 15, 1993. l l

If you should have any questions on this matter, please contact Mr. J. M. Pinzon at (512) 912-8027 r;me at (512) 972-8664.

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'J . F.<Croth t' 1 Vice President, Nuclear Generation 1 DNB/pa

Attachment:

Revision 1 to LER 93-016 (South Texas, Unit 1)

LER-93\L93016R1.01 Project Manager on Behalf of the Participants in the South Texas Project 9307220320 DR 930715 m / f, g ADOCK 05000498 y 1 j]

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1 Houston Lighting & Power Company South Texas Project Electric Generating Station ST-HL-AE-4506 File No.: G26 Page 2 l I

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l Regional Administrator, Region IV Rufus S. Scott i Nuclear Regulatory Commission Associate General Counsel 611 Ryan Plaza Drive, Suite 400 Houston Lighting & Power Company j i Arlington, TX 76011 P. O. Box 61867 l

! Houston, TX 77208 I L. E. Kokajko Project Manager U.S. Nuclear Regulatory Commission Institute of Nuclear Power Washington,.DC 20555 13H15 Operations - Records Center 700 Galleria Parkway Atlanta, GA 30339-5957 Senior Resident Inspector c/o U. S. Nuclear Regulatory Dr. Joseph M. Hendrie l Commission 50 Bellport Lane

P. O. Box 910 Bellport, NY 11713 )

Bay City, TX 77414 i D. K. Lacker ,

J. R. Newman, Esquire Bureau of Radiation Control i Newman & Holtzinger, P.C., STE 1000 Texas Department of Health 1615 L Street, N.W. 1100 West 49th Street Washington, DC 20036 Austin, TX 78756-3189 D. E. Ward /T. M. Puckett U.S. Nuclear Regulatory Comm.

Central Power and Light Company Attn: Document Control Desk j P. O. Box 2121 Washington, D.C. 20555 ;

Corpus Christi, TX 78403 l J. C. Lanier/M. B. Lee City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 K. J. Fiedler/M. T. Hardt City Public Service P. O. Box 1771 San Antonio, TX 78296 LER 93\L93016R1.U1

NRC FC3M 366 U.S. NUCLEAR REGULATORY 00pO4]SSIC) APPROVED BY (M8 NO. 3150-0104 (542) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH

' LICENSEE EVENT REPORT (LER) M"$I3fS gu RE RDlWG BUR EN S THE INFORMATION AND RECORDS MANAGEMENT BRANCH TE O I (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION,

! (See reverse for required ruber of digits / characters for each block) WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK i REDUCTION PROJECT (3150 0104), OFFICE OF l MANAGEMENT AND BUDGET. WASHINGTON. DC ?O503.

l FACILITY NAE (1) DOCKET NLMBER (2) PAGE (3) l South Texas Unit 1 05000 498 1 OF 6 1

TITLE (4) Technical Specifications Violation due to Circuitry for the Steam Generator Power Operated Relief Valves and Post Accident Monitoring Instruments Being inoperable EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

SE T AL RE FACILITY WAME DOCKET NUMBER MC31H DAY YEAR YEAR MONTH DAY TEAR STP UM T 2 05000 499 FA n NAM CKET E 05 03 93 93 -- 016 -- 01 07 15 93 g 90 OPERATING THIS umi IS SusMinrD mSuANT TO THE RmiREMENTS OF 10 CrR e peck = or mmi (n)

C]DE (9) 5 20.402(b) 20.405(c) $0.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)(1)(1) 50.36(c)(1) 50.73(a)(2)(v) 73. 71(c)

LEVEL (10) 0 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER 20.405(a)(1)(iii) X 50.73(a)(2)(1) 50.73(a)(2)(vii i )( A) (specify in Abst et ow 20.405(a)(1)(iv) 50.73(a)(2)(li) 50.73(a)(2)(vill)(B) 20.405(a)(1)(v) 50.73(a)(2)(il1) 50.73(a)(2)(x) NRC Form 366A) llCENSEE CONTACT FOR THIS LER (12)

NAM TELEPHONE NUMBER (include Area Code)

Jairo Pinzon - Senior Engineer (512) 972-8027 CCNPLETE ONE LINE FOR EACH CEMPONENT FAltURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER

[ g l

l l l l SUPPLEMENTAL REPORT EXPECit.) (14) EXPECTED MONTH DAY YEAR I l YES SUBMISSION (If yes, complete EXPECTED SUBMIS$10N DATE). X WO DATE (15)

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

On May 3, 1993, at 1640 hours0.019 days 0.456 hours 0.00271 weeks 6.2402e-4 months , Unit 1 was in Mode 5 at 0% power and Unit 2 defueled. It was discovered that circuitry for the Unit 1 Steam Generator Power Operated Relief Valves and Post Accident Monitoring Instruments had not been configured in its qualified condition since January 4, 1993. This discovery was made during review of a work package. The work package indicated that screws were missing from the circuit card cages and power supply racks in the Qualified Display Processing System and an engineering evaluation that had been requested had not been performed. The cause of the event is less than adequate work practices in not replacing the screws following maintenance activities. Contributing factors include less than adequate knowledge of seismic fastener requirements and the failure to assess the impact of the missing screws in a timely manner. Corrective actions for this event include replacing the missing screws, inspecting other similar equipment for missing screws, reviewing work documents for other uncompleted engineering evaluations, improving maintenance work practices, training with regard to equipment qualification, and enhancing the process by which deficient conditions are evaluated by engineering.

N2C FORM 366 (5-92)

LER-93\L93016R1.U1

NRC FORM 366A U.S. ILICLEAR REGJLATORY C0041SS10N APPROVED BY OMB NO. 3150-0104 (5 9?) EXPlRES 5/31/95 ESilMATED BURDEN PER RESPONSE TO COMPLY WITH THl$

INFORMATION COLLECTION REQUEST: 50.0 HRS.

"" " ' ^ " " ""

LICENBEE EVENT REPORT (LER) $R 7714),

T ON AND RECORD LANAGEMENT BR NCH MN TEXT CONTINUATION u.S. NUCLEAR REGULATORY COMMISSION, WASHikGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31$0-0104), OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON, DC 20503.

FAcitITY NAME (1) DOCKET WUMBfR (2) tra NUMarR (61 PAGF (3)

YEAR SEQUENTIAL REVISION South Texas, Unit 1 05000 498 2 OF 6 93 --

016 -- 01 TEXT (If more space is reouired use additional cooles of NRC Form 366A) (17)

DESCRIPTION OF EVENT:

4 On May 3, 1993, at 1640 hours0.019 days 0.456 hours 0.00271 weeks 6.2402e-4 months , Unit 1 was in Mode 5 at 0% power and Unit 2 dofueled. It was discovered that circuitry for the Unit 1 Steam Generator Power Operated Relief Valves (S/G PORVs) and Post Accident Monitoring

, Instruments had not been configured in its qualified seismic condition since January 4, 1993. This discovery was made during review of a work package.

The work package indicated that screws were missing from the circuit card cages and power supply racks in the Qualified Display Processing System (QDPS) and an engineering evaluation that had been requested had not been performed.

On January 4, 1993, a Service Request (SR) was written by the QDPS System Engineer concerning missing seismic hold-in screws in the Unit 1 QDPS. The SR was written to resolve a problem associated with Maintenance workers failing to replace the screws following maintenance activities in the Unit i refueling outage.

The Shift Supervisor reviewed the SR and annetated on the SR that an engineering evaluation, called a Conditional Release Authorization, was nacessary to determine if the QDPS could be relied upon to perform its design function under all analyzed conditions. Neither the System Engineer or Shift Supervisor identified the missing screws as a potential operability issue and the affected equipment was not declared inoperable. The SR was delivered to the Maintenance Planning Division for processing and data entry, but following data entry, the SR was inadvertently filed instead of baing forwarded to the Technical Support Engineering Group for the l Conditional Release Authorization that the Shift Supervisor had determined I was necessary.

On April 28, 1993, during a review of the associated SR package, which was prompted by the NRC Diagnostic Evaluation Team, it was determined that the engineering evaluation had not been performed.

On April 29, 1993, the SR was given to the Design Engineering Department to cvaluate the effect of the missing screws. A walkdown was performed that identified specific locations for missing screws in the QDPS.

On April 30, 1993, the walkdown data was provided to Westinghouse Corporation for seismic review and impact assessment. Westinghouse dstermined that portions of the QDPS were not in a seismically analyzed condition with screws missing from the card cages and power supply racks.

LER-93\L93c .01

NRC FORM 366A U.S. NUCLEAR REEJLATORY CopptlSSION APPROVED BY CMB No. 3150-010.

(5-9?) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY blTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

LICENSEE EVENT REPORT (LER) $0RM$Tf0NAWD RE D MA C M NT BR NCH MN TEXT CONTINUATION 7714), u.s. NUCLEAR REGULATORY COMNISSION, WASHlWGTON, DC 20555-0001 AND TO THE PAPECWORK REDUCTION PROJECT (31$0-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON OC 20503.

FACILITY MAME (1) DOCKET NUMRER (?) (fR NUMBER (61 PA T (3)

SEQUENTIAL REVISION YEAR

"# 8 ' " " * "

South Texas, Unit 1 05000 498 3 OF 6 93 --

016 -- 01 TEXT (If more space is recuired. use additional coDies of Nec Form 3664) (17)

DESCRIPTION OF EVENT: (Cont'd)

On May 3, 1993, at 1640 hours0.019 days 0.456 hours 0.00271 weeks 6.2402e-4 months , STP personnel determined that violation of Technical Specifications 3.7.1.6 and 3.3.3.6 had occurred because circuitry i for the Unit 1 S/G PORVs and the RCS Subcooling Margin Monitor had been l technically inoperable from January 4, 1993, until February 11, 1993, when l Unit 1 entered Mode 5 and the S/G PORVs and the RCS Subcooling Monitor were l no longer required to be operable.

The NRC Operations Center was notified of this event on May 4, 1993, at 1104 hours0.0128 days 0.307 hours 0.00183 weeks 4.20072e-4 months .

! I l

CAUSE OF EVENT:

The root cause of this event is less than adequate work practiceu in that the screws were not replaced following maintenance activities. Contributing factors include less than adequate knowledge of equipment qualification !

rcquirements, and failure to evaluate the impact of the missing screws in a timely manner.

ANALYSIS OF EVENT:

During investigation of this event, it was revealed that the System Engineer .

had written the SR to resolve a condition that had existed intermittently I I

for the two years he had been the QDPS System Engineer. The System El%;1neer had kept notes, dated back to August 1992, that indicated that the condition )

also affected the Unit 2 QDPS.

Subsequent to the NRC notification on May 4, 1993, Westingis se performed a l more detailed analysis to determine the seismic adequacy of the card cages and power supply racks using the specific locations and numbers of missing i ccrews. The more detailed analysis indicated that some of the card cages and power supply racks that were initially considered to be seismically unacceptable were acceptable in their current configuration.

Using the list developed in the more detailed Westinghouse analysis, HL&P has identified the controls and indications in each unit that could have bsen affected by a seismic event. The Unit 1 S/G PORVs and RCS Subcooling Margin Monitors were not affected as originally reported to the NRC, but the circuitry for other Post Accident Monitoring Instruments on both units, as wall as two S/G PORVs on Unit 2, were affected.

l l

l LER-93\L93016R1.U1

NRC FORN 366A U.S. MUCLEAR RE(11LATORY fXMMISSION APPROVED BY CMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

C" " S RE " " " '

LICENBEE EVENT REPORT (LER) N"! yow"ANoRtCORD g ANAGEM NT BR NCH M TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASWikGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31$0-0104), OFFICE OF MANAGEMENT AND BUDGET. LASHINGTON, DC 20503.

FACIllTY NAME (1) DOCEIT WlMBER (2) LER NLMBFR (6S PAGE (3)

SEQUENTIAL REVISION YEAR South Texas, Unit 1 05000 498 4 OF 6 93 -- 016 -- 01 TEXT (If more soace is reauired, use additional cooles of NRC Form 366A) (17)

ANALYSIS OF EVENT: (Cont'd)

Although the controls and indications may not have failed during a seismic cvent, HL&P assumed that the controls and indications were failed to conservatively assess the operator's ability to shut down the plant if a ;

scismic event had occurred while the screws were not installed. Using the l' lists of controls and indications that were assumed to have failed, and taking credit for other qualified controls and indications that were not affected by missing screws, HL&P has determined that Units 1 and 2 had sufficient redundant capabilities to perform a safe shutdown of the plant after a seismic event even if a loss of offsite power had occurred coincident with the seismic event.

After the affected controls and indications were identified, HL&P determined l that Technical Specification allowed outage times, in addition to those initially reported, were exceeded because the affected controls and indications were not recognized as being unqualified. The list of affected controls and indications differs for each unit, but collectively, allowed outage times were exceeded for action statements located in Technical Specifications 3. 3.1, 3.3.2, 3.3.3.5, 3.3.3.6, 3.4.11, 3.7.1.2 and 3.7.1.6.

4 The allowed outage times varied from 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months to 60 days, depending on the control or indication affected.

The S/G PORVs are required for decay heat removal and safe cooldown in accordance with Branch Technical Position RSB 5-1. In the safety analyses, operation of the S/G PORVs is assumed for mitigation of small break LOCA, feedwater line break, loss of normal feedwater, and loss of offsite power.

Operability of post accident monitoring instrumentation ensures that sufficient information is available on selected plant parameters to monitor and assess these parameters following an accident. The design, gitalification and display criteria for Post Accident Monitoring Instruments are described in the South Texas Project Electric Generating Station Updated Final Safety Analysis Report, Section 7B, and meet the intent of Regulatory Guide 1.97, Revision 2, " Instrumentation for Light Water Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident,"

December 1980.

During the time that the Units 1 and 2 QDPS seismic hold down screws were missing, the systems provided the required indication and control functions needed to safely operate Units 1 and 2. Therefore, this event did not have an adverse affect on public health or safety.

Failure to meet the requirements of the Technical Specifications is reportable pursuant to 10CFR50.73 (a) (2) (1) (B) .

LER 93\L93016R1.U1

NRc FORM 366A u.s. NUCLEAR REGULATORY CXBetISSION APPROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95

~

ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS

INFORMATION COLLECTION REQUEST: 50.0 HRS.

MMEN ' ^ "$'

LICENSEE EVENT REPORT (LER) $ $ 1[oN AND REC 0RD A GEM NT BR NCH M TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMISSION, I I

WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK l l REDUCTION PROJECT (31$0-0104), OFFICE OF 4 MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

(

FACILITY NAMF (1) DOCKET WlMBER (2) LER NtMBER (6h PAGF (3) l EEQLENTIAL REVISION YEAR

, South Texas, Unit 1 05000 498 5 OF 6 l

93 -- 016 -- 01 l

TEXT (If more sonce is reoutred. use additional cooles of NRC Form 366A) (17)

CORRECTIVE ACTIONS Tha following corrective actions address the specific conditions in Units 1 l and 2 and the generic implications of the event. l

1. The screws missing from the Unit 1 QDPS have been replaced.

2. Walkdowns of other similar components were performed to determine if other potential operability issues existed due to missing screws. No i other reportable conditions were identified. The screws missing from j the Unit 2 QDPS will be replaced prior to Unit 2 startup.

l 3. Open SRs were reviewed to determine if non-conformances that potentially affect operability have been identified and resolved. No additional issues affecting operability were identified.

4. The Operations Work Control Group that screens new SRs has been trained on equipment qualification requirements to enable them to properly identify conditions similar to those which occurred in this event.

5. The Maintenance Department has issued a training bulletin to address conficJuration management as it relates to maintenance work practices. l To reinforce the importance of configuration management, the training i bulletin will be discussed in the Maintenance Department Manager's i quarterly meeting by August 1, 1993. l

6. The process for obtaining Conditional Release Authorizations will be enhanced to include specific processing requirements and to clearly define process accountability. This enhancement will be completed by l September 17, 1993. Until this enhancement is fully implemented, the Operations Department will track Conditional Release Authorizations to ensure the timely evaluation of indeterminate conditions.

7. Training on equipment qualification has been provided to System Engineers.

Additional Information:

No previous events have been reported where the seismic qualification of a component caused a Technical Specification violation. However, Unit 2 Licensee Event Report 93-008, " Technical Specifications Violations Due to Failure to Maintain Equipment Qualification of a Residual Heat Removal System Motor Operated Valve," describes an event where a motor operated valve was not configured in an environmentally qualified condition due to a missing "T" drain. Generic corrective actions, which address the generic implication of the missing screws in the QDPS and the missing "T" drain in the motor operated valve, are being addressed by Unit 2 Licensee Event Report 93-008.

LER-93\L93016R1.U1

NRC FORM 366A U.S. NUCLEAR REGULATORY CG NISSION APPROVED BY (MB NO. 3150-0104 (5 92) ,

EXPIRES 5/31/95 ESilMATED BURDEN PER RESPONSE TO COMPLY WITH THis

INFORMATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESilMATE TO THE LICENSEE EVENT REPORT (LER) INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB TEXT CONTINUATION 7714), U.S. NUCLEAR REGULATORY COMMIS$10N, WASHINGTON, DC 20555 0001 AND TO THE PAPERWORK REDUCTION PROJECT (31$00104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACitITY NAME (1) DOCKET WLMBER (2) LER WLMBER (6S PAGE (3)

SEQUENTIAL REVISION YEAR l South Texas, Unit 1 05000 498 6 OF 6

! 93 -- 016 -- 01 1

TEXT (If more space is reautred, use additional cooles of NRC form 366A) (17) bdditional Informatign:

l Unit 1 Licensee Event Report 90-024, " Failure to take Technical Sp:cification Actions With One Channel of [RCS) Subcooling Margin [ Monitor) l Inoperable," described an event where the Display Processing Units within l the QDPS were inoperable, but the effects of the inoperability were not

[ cppropriately considered. The cause of the event in LER 90-024 was sufficiently different from the cause of this event such that the corrective actions described in LER 90-024 would not have been expected to preclude this event.

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I LER 93\L93016R1.U1 l

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ML20045J028

Text

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