05000289/LER-1998-001, :on 980122,failure to Operate & Maintain Flow Instruments within Design Basis Occurred.Caused by Improper Application of Stds for Resolution of Degraded or non- Conforming Conditions.Operators Trained

:on 980122,failure to Operate & Maintain Flow Instruments within Design Basis Occurred.Caused by Improper Application of Stds for Resolution of Degraded or non- Conforming Conditions.Operators Trained

ML20203G766
Person / Time
Site:	Crane
Issue date:	02/23/1998
From:	Knight M GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20203G754	List: 05000289/LER-1998-001, :on 980122,failure to Operate & Maintain Flow Instruments within Design Basis Occurred.Caused by Improper Application of Stds for Resolution of Degraded or non- Conforming Conditions.Operators Trained
References
GL-91-18, LER-98-001, LER-98-1, NUDOCS 9803030061
Download: ML20203G766 (5)

LER-1998-001, on 980122,failure to Operate & Maintain Flow Instruments within Design Basis Occurred.Caused by Improper Application of Stds for Resolution of Degraded or non- Conforming Conditions.Operators Trained

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(ii)
2891998001R00 - NRC Website

text

.

NRC &Ol4M 366 L!.$. ht'C11Ak k6 Gt'IATORY CO%tMisMON APPRO) ED in OM B No. JiO.0104 (6 93)

EXPIRE 5 0&S8/98 g

I.ST! MATED BURDEN PLR RESPONSE TO COMPI Y WITil Tills MANDATORY INFORNtATION COLLECTION REQUEST 500 HRS RLh)RTLD li.SSONS LEARNED AkE INCORMikATED INTO T1D LICENSEE EVENT REPORT (LER)

LiCENstwo Pux tss AND FLD B^rk TO iNDuS1RY rORwARD COMMEN*f S REGARDING HUkDEN LSTiktATL 10 THE INT ORMATION f t\\ sfI (Sce reverne for reqtured numtet of It A i IN T.kX l5 m01 digrischaracters far each t incl) lilE PAPERWORK kEDtK' TION PROU"I (U h 0104), of71CE Of MANAGEMENT AND 14UDGET. W ASilINO TON. DC 20M FACilJT) N AME 08 DOCKET NUMBER O)

P AG E (J)

TIIREE hi!LE ISLAND, UNIT I 05000289 1 OF 5 TkIll(4)

FAILURE TO OPERATE AND htAINTAIN FLOW INSTRUh1ENTS WITHIN DESIGN BASIS DUE TO MISINTERPRETATION OF DESIGN REQUIREN1ENTS EVLNT DAl E (5) l Ilk NTM DER toi hEPOWT DATE G)

OTllEk li.CIIJ llES INYOLVED @)

MONTil DAY YEAR YEAR SEg AL REV1310N MONTl!

DAY YEAR FAGL3 TV NAMI.

IXx RET NUMr4EK 01 22 98 98 001 00 02 23 98 OPERA 1ING Tillh REPORT IS M BMITTED PL RSL:ANI 1O Tile (E QL IREMENTS OF le Cth b- (Chetk one or nwre) tII)

MODE (9)

N m;N :

o;uwe m x

N> 73e o 30 73e%

POM EH 20 220 ka gl) 20 Nuka C N "X

$07haK2Mut 50 7kax2)UL)

LEVELOO) 100 u;mm m u ;;o3%3_n u, 30 7Aa(;x j 73 7i 20 220 KaM 2 X u) 20 :20 X a M 4)

$0 7 h a M 2)t iv)

OTithR 20 ;;0wa(;km) 503% )(1) 50 7haX;xs)

Specdv m Ahntract below 20;;0Na(;nn) 50 34E x2)

?O 7.Ka(; nvu) 1JCEN5EE CONTACI E OR TilM LER O 4)

NAME TII.I FirGiE hulM.R Undele Area Code) ht. R. KNIGiff, Thil LICENSING ENGINEER (717) 948-8554 COMPLETE ONE IJNE FOR FACll COMPONENT FAILlRE DESCRIHFD IN TIIM REPORT (1J)

CAU5b SYSTEM CLAfPt >NINT MANEf AL'TURiiR R

RT I E

CAUSE

SYSTEM COMPT 3NENT MANtT ACTl'RER RI'l R ATLE 1

i MTPIIMENTAI.kEPORT EAPETED 04)

EXPFCTF.D MONTil DA)

YLAR M'DMISMON

- 3g g

(If yes, complete EXPECTED SlSMl"SION DATE)

ABN TRACT d.mut to l+o siwes. i e. apptoumaiciv i 5 smgie-slwed tve muen imes) O a)

On January 22,1998 GPU Nuclear de: ermined that in 1995 and 1996 a flow instrument had been inoperable for greater than the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> permitted by Technical Specification (TS). These conditions are reportable in accordance with 10CFR50.73.(a)(2)(i). A 1993 evaluation had determined that flow indicators were not needed because of alternate non-qualified indication.

While reviewing this event, GPU Nuclear also identified that the Building Spray (BS) fiow indicators were not qualified to meet Regulatory Guide (RG) 1.97, Category I requirements. An evaluation had justified Category 2 qualified BS flow indication based on confid.mee the pump would meet performance requirements with less than the required NPSH margin. This condition is outside design basis and reportable in accordance with 10CFR50.72(b)(1)(ii)(B) and 10CFR50.73(a)(2)(ii). The root cause of this event was improper application of the Generic Letter (GL) 91-18 standards for resolution of degraded or non-conforming conditions. Use of a non-qualified instrument has been justified as an interim measure, not a long-term resolution. The inoperable flow instruments did not pose a risk to nuclear safety significantly beyond that evaluated as acceptable per TS. Operators have been trained; guidance will be provided to PRG members; procedures will be enhanced; and design deficiencies will be corrected.

9003030061 980223 PDR ADOCK 05000289 PDR S

NRC PORM 3SSA U S. NUCLEAR 5.EAULATORY COMMIS&lON (4-96>

LICENSEE EVENT REPORT (LER) 4 TEXT CONTINUATION PACILITY NAME (it DOCKET LER NUMSER (4)

PAGE (3)

THREE MILE ISLAND, UNIT 1 0$000289 2

OF 5

98 001 00 TE AT pr true space de required, use adthhanalcopw of NRC Form 366% (17)

~

FAILURE TO OPERATE AND MAINTAIN FLOW INSTRUMENTS WIT 111N DESIGN BASIS DUE TO MISINTERPRETATION OF DESIGN REQUIREMENTS 1.

Plant Operating Conditions before Event:

TMI l was operating at 100% reactor power.

II.

Status of Structures, Components, or Systems that were Inoperable at the Start of the Event and that Contributed to the Event:

None 111.

Background:

In 1993 the TMI l Plant Review Group (PRG) concluded that the flow instrumentation for High Pressure injection (HPI), Low Pressure injection (LPI) or Reactor Building Spray (BS) systems were not required for system operability and that the Technical Specifications 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowable outage time did not apply for these flow instruments (Reference; PRG Meeting No.93-066, September 9,1993). Although it was concluded in 1993 that these instruments were not required for system operability, the PRG stated that 1) both system trains ofinstrumentation should not be taken out of senice at the same time,2) because of the importance of this instrumentation, care should be taken in allowing removal of a flow instrument from senice, and 3) the instrument should be retumed to senice expeditiously, On December 19,1997 the PRG met after engineers had questioned the validity of the 1993 PRG guidance (Reference: PRG Meeting No.97-090, December 19,1997). The PRG concluded that control room flow indication is required for the HPI, LPI, and BS systems to perform their intended safety function under all conditions within the design basis. During a design basis accident the flow instruments are required to throttle system flow to maintain pump operation within design specifications either to maintain the required Net Positive Suction Head (NPSH) or to prevent pump runout. Because GPU Nuclear had relied upon incorrect operability guidance since 1993, the PRG requested a review of the maintenance history for the subject flow instruments since January 1,1993 to determine if any of these instruments had been out of senice in excess of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Technical Specification (TS) 3.3.2 Liniting Condition for Operation (LCO) allowable outage time.

IV.

Event Description

On January 22,1998 the PRG met to evaluate the results of a review which determined that on two occasions flow instruments required for system operability had been allowed to remain inoperable for gicater than the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowable outage time permitted by Technical Specification (TS) 3.3.2. It was determined that a flow indicator for Reactor Building Spray__

NRC FDilM M4A V t. NUCLEAR REOULAf oRY Commission (4 95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINJATION P ACILITY NAMs (1)

DoCKEI LER NUMSER (tl PAGE(3l THREE MILE IStxND, UNIT 1 l 05000289 3

OF S

98 001 00 ten 9 m me we a memt use ammimm.wmc rorm w) on (BSI Fl.2) had been inoperable for approximately 122 hours0.00141 days <br />0.0339 hours <br />2.017196e-4 weeks <br />4.6421e-5 months <br /> between August 24 and August 29, '995. On another occasion, a Dow indicator for llPI (MU FI l 129) had been out of scryice for approximately 97 hours0.00112 days <br />0.0269 hours <br />1.603836e-4 weeks <br />3.69085e-5 months <br /> between November 22 and November 26,1996. In each case Technical Speci0 cations (TS) Section 3.3.2 permits removal of the component from senice for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for maintenance or testing that affects only one train of the system. Therefore, GPU Nuclear cie. W that these conditions were a violation of TS Section 3.3.2 and thus are reportable in accou uc with 10CFR$0.73.a.2a as an operation or condition prohibited by the plant's Technical Specificatioru The subsequent review af this event, performed during the preparation of this LER, identined a design denciency of the ils cor, trol room now indicators (HSI Fl.1 and BSI F12). These instruments are nceded to perform safety relawi actions and they are required to be quali0ed to meet Regulatory Guide (RG' l.97, Category 1. The BS Dow instrun.ents lIlE/Fil' meet RG 1.97 Category 2 but not Category I requirements. The llPI lilQ/Fil and LPi lllP/Fll 0ow instruments meet RG 1.97 Category I requirements. On February 19,1998 the PRG determined that the BS Dow instrument design denciency constitutes a condition outside the design basis of the plant uhich is reportable in accordance with 10CFR$0.72(b)(1)(ii)(ll) and 10CFR50.73(a)(2)(ii) and the NRC was properly notified.

V.

Component Data:

There were no component failures applicable to this licensee event report.

VI. Identification of Root Cause The root cause of this event was an improper application of the standards for resolution of degraded or non-conforming conditions contrined in Generic Letter (GL) 91 18, speci0cally, INPO Root Cause Classincation: mist.pplication or interpretation of design inputs (engineering codes & standardt segulatory requirements, design basis, design criteria).

The 1993 PRO guidance that ilPI, LPI, or 11S systems could be operable without now indication was wrong. In 1988 the emergency procedures were changed to add the requirements for throttling BS How and thus the operating ftmetion of these instruments was changed. The evaluation at that time concluded that system performance requirements w.dd be met without BS Gow indication. (Reference: FSAR Update 8, dated July 1989. tan

2. " Evaluation of TMI-I Compliance with Regulatory Guide 1.97 Requirements Cato o ameters," item No.8).

That evaluation recognimi that the Dow instrument was requaed te are that the BS pump is operated with the required NPSil as speci0ed by design. It was o~

aded that operation with

.ess than the required NPSil margin was acceptable for the shon x during an accident when the Building Spray Pumps would be required. Ilowever, no los!, rm followup a6tions were taken and the issue was considered complete.

me rom m aw

NRC r^ vivi 300A U S. N'ICLEAR RE AVLAsoRY COMMISSION (4 DS)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION F ACILisY NAMt W DOCKti LER NUMSER (4)

P A"> E (3)

THREE MILE ISLAND, UNIT 1 05000289 4

OF 5

98 001 00 if xs tu me space a reen.a m entwoo avm o nnc rarm assr (1rn r

in 1993 the PRO determined that alternate indications could be used in lieu of the control room flow instmmentation. Although the attemate indications may have prosided the information required to operate the pump within its design speci0 cations, the alternate instniments did not meet RG 1.97 requirements, in summary, when throttling of BS flow was added to the cmcrgency procedures in 1988 and when the 1993 PRO met to discuss now instmment operability requirements, an " operable but degraded or nonconforming"justi0 cation was misinterpreted as meeting design requirements.

GL 91 18 states that " operability and qualification are closely related concepts. Ilowever, the fact that a system is not fully qualified does not, in all cases, render that system unable to perform its specined function if called upon." The GL accepts that components may be operable even though they do not meet all of the design requirements or there are variations from design specifications and continued operation may be justined with an operable but degraded or nonconfonning system, structuie, or component (SSC). In such a case, the design speci0 cation variance or use of non-qualified equipment is only an interim measure and these exceptions from design requirements are not acccmble as long term resolutions. The GL states that the licensee should restore the quality of the system.

Vll. Assessment of the Safety Consequences and implications of the Event:

The inoperable flow instmments did not pose a risk to nuclear safety significantly beyond that which had presiously been evaluated to be acceptable.11PI, LPI & BS Dow instruments are all calibrated and maintained in accordance with the QA program. In 1993 GPU Nuclear recognized the importance of these instruments when the PRO instructed that out of senice time should be limited with priority given to any repair work and that one of the redundant instmr'ents should be available at all times During the periods when a BS flow instrument was out of senice for 122 hours0.00141 days <br />0.0339 hours <br />2.017196e-4 weeks <br />4.6421e-5 months <br /> between August 24 and August 29,1995 or when an llPI flow instrument was out of senice for 97 hours0.00112 days <br />0.0269 hours <br />1.603836e-4 weeks <br />3.69085e-5 months <br /> between November 22 and November 26,1996, the redundant ES train remained in senice. TMI l Technical Specifications Section 3.3.2 recognizes that a single train may be out of servac for maintenance and permits one train of the system to be removed from senice based on the low probability of an event during that period Although dunng the periods described above, BS How indication or 11PI Dow indication were allowed to remain out of senice for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> as permitted by the Technical Specifications, the amount of time these instruments were out of senice were limited to relatively short periods of time,122 and 97 hours0.00112 days <br />0.0269 hours <br />1.603836e-4 weeks <br />3.69085e-5 months <br />, respectively, in 1988, the design basis of the building spray system was changed. The NPSil available to the BS pumps when taking suction from the RB sump was reduced when the BWST low level setpoint was increased. To account for this, the emergency operating procedures were revised to

-- - require operator action to throttle BS flow prior to BS pump operation taking suction from the RB sump. This action reduced the BS pump NPSli requirement sufTicient to maintain adequate NPS11 margin. It was recognized that the BS flow instrument was not qualified ~.o RG L97 Category I requirements. An evaluation was performed whichjustined the lack ofinstrument

~NRC FORM 366A (4-95'

^

gs'tmpaseA U 8. NUCLP44 REOULAsORY CoMMittON 3

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION j

P ACILisY NAME (1)

DOCKET LOR NUMSSR (4)

PAGE (3) i YEAR Tfe74 E#

i

.THREE MILE ISLAND, UNIT 1 05000289 5

OF 5

98 001 00 isns gnm we a nnuumt. m annma usm amc nm mn pr>

qualification based on confidence that the pump would meet the s) stem perfonnance requirements i

without the required NPSil margin. That evaluation was a valid assessment of the safety j

implications of this design deficiency and remains valid until corrective actions identified in i

Section IX below have been completed.

i Vill. Previous Events of a Similar Nature:

I No previous events of a similar nature were identified.

f i

r IX. Corrective Actions:

4 A.

Licensed operators have been briefed and were provided with training materials to ensure j

they are aware that the operability of BS, LPI and ilPI How indications is required to meet Technical Specification 3.3.

A B.

GPU Nuclear will provide clari0 cation for PRG members on the use of NRC guidance in GL 91 1R by May 1998 C.

Procedures that remove BS, LPI or llPI How instmments from senice (1302 5.18, l

"11Pl/LPI Flow Channel Calibration," and 1302 14.1, " Calibration of IST Related instruments,") will be revised prior to the next perfonnance of the procedure to identify the required allowable outage time 1-mitted by TS 3.3.4. Currently the next performance of i

j these procedures is scheduled for September 1998.

D.

IN flow instrumentation will be modified to meet RG 1.97 requirements or the design basis usc of these instruments will be modified no later than plant stanup from the next refueling outage, the Cycle 13 Refueling (13R) Outage, which is scheduled to begin in l

September 1999.

' The Energy Industry identification System (Ells), System identification (SI) and Component i

Function Identification (CFI) Codes are included in brackets, "[SI/CFl]." where applicable, as required by 10 CFR $0.73 (b)(2)(ii)(F).

i b

mc roRu aceA em) r

.-way._.~.r-

.------,,,,,,-,yw,.,m%ne-e

.-.j._

gy., _

y. mw

.w....g_._,

cmm,,,-,.g4.,-...

._w n,

,.-.,.,,,.y.--e r