ML18026A493

LER 97-007-01:on 971017,entry Into TS 3.0.3 Occurred to Allow Completion of Surveillance Testing of One Channel of Rbm.Caused by Failure of Components in LPRM Output to Rbm. Submitted TS Change Request to Extend LCO Action Statement

ML18026A493
Person / Time
Site:	Susquehanna
Issue date:	03/30/1998
From:	Ellis S PENNSYLVANIA POWER & LIGHT CO.
To:
Shared Package
ML17159A235	List: ML17159A234 ML18026A493
References
LER-97-007, LER-97-7, NUDOCS 9804090017
Download: ML18026A493 (6)

Text

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NRC FORM 366 UCLEAR REGULATORY COMMISSION PPROVED SY OMB NO. 31504104 (4'&SI EXPIRES 04I30IBS BVRDEN PER RESPONSE TO COMPLY WITH THIS MAN(IATORY INFORMATION COLLECTION REOUESTJ 60.0 HRS.

LESSONS LEARNED ARE INCORPORATED INTO THE LXCENSEE EV1KT REPORT (LER) REPORTED ucENslJJG pRocess AND FED BACK TO INDUSTRY. FORwARD COMMENTS REGARDiNG BURDEN ESTIMA'lE TO THE INFORMATION AND RECORDS MANAG'EMENT BRANCH (T.S F331. U.S. NUCLEAR (See reverse for required number of REGULATORY COMMISSION, WASHINGTON. DC 2055$ 400I, AND digits/characters for each block) 'To THE PAPERWORK REDUCTION PRO~CT I3 I SDOIDAIi OFFICE OF MANAG/M6NTAND BUDGET, WASHING1ON, DC 20503.

FAcrtJTT JJAMa I i) ooclttT Jrv M atri QI Fnoa ar Susquehanna Steam Electric Station - Unit 2 05000388 1OF5 HJ Entry Into Technical Specification 3.0,3 - Rod Block Monitor Operability Testing R ER (6) REPORT DATE (71 THER FACILITIES INVOLVED (81 MOJttrt OAT ac QvfittrAL ~ Jttvlsrorr Morrtrr OAT TEAJt JJAM 6 JAJMIIUI NVMtN 98'ACAJTT 05000 10 17 97 97 007 01 03 30 JACLJTT JJAME 05000 EPO T IS SUBMITTED PUR SUANT TO THE REQUIREM TS OF 10CFR 6: (Checitone Or more) (11)

MODE (9) 20.2201 (01 ZoiZ 0 la) v 50.73(a1( Iti) 50.73(a)(2)(viii)

POWER 20,2203(a)(l) 20.2203(a)(3) (I) 50.73ta) (2) Oi) 50.73(a) t2) (Jt)

LEVEL (10) 100 20.2203(a) (21(r) 20. ZO (aII Iln) 0. 3(a1( Itrrrl 73. 1 20,2203(a) (2)(li) 20.2203(a) (4) 50.73(a)(21(iv) OTHER O. a) m 0.36lc)(1) ta)(2)(v) poetry In Abstra ct btlow orln NRC Form 366A 20.2203(a)(2] liv) 6(cll I 50.73(a)( ](vrrl o UC S E CDNTAC 0 HLs L 12)

JJAMK TRKFJJOJra JJVMFOt tlC4A Arto crrrJJJ Stephen J. Ellis - Nuclear Licensing Engineer 717/542-3537 COMPlETE ONE UN OR COMPONENT FAILURE DESCRIBED IN HIS REPORT(13)

CAUS i coMF0 Jrttrr MAJJUFAcrvrrot STsttM coMFoirotT SVPPLEIVIENTAL T ECTED (14) EXPECTED MONTH DA SUBMISSION YES X NO DATE (15)

(If yes, comp)cte EXPECTED SUBMISSION DATE).

ABSTRACT (Limit 1O 1400 SPaCeS. I.e.. aPPIOJCmately 15 Srn()lmPaCeo tyPeVvrrtten linea) (16)

On October 17, 1997, at 0920 hours0.0106 days <br />0.256 hours <br />0.00152 weeks <br />3.5006e-4 months <br />, with Unit 2 in Condition 1 (power Operation) at 10(W Power, a Technical Specification 3.0.3 entry was votuntan1y made. In accordance with the guidance of NUREG 1022, a Technical Specification 3.0.3 entry requires an LER to be submitted within 30 days of the event. The entry was made to allow completion of surveillance testing of one channel of the Rod Block Monitor (RBM), after considering the other available options. There is no provision provided in current Technical Speciticatlons to allow operability testing without entry into Technical Specification 3.0.3. The Technical Specification 3.1.4.3 ACTION statement had been entered to perform sulveit)ance testing of one channel of the RBM. Unexpected results had been obtained during the testing.

Investigation of these results determined that 11 LpRMs were not providing an output to the RBM. The testing resumed prior to the expiration of Technical Specification 3.1A.3 ACTION allowable time limit, but would not be completed before the limit expired.

Operations management votuntarily entered Technical Spe:ification 3.0.3, and did not take the ACTIONS described in Technical Specification 3.1A.3.a, that is placing the inoperable channel of the RBM tn the trip condition. In reconsidering this event, PPLL has recognized that the ACTION of Technical Specification 3.1.4.3.a should have been taken to avoid a condition that could be construed as an entry into Technical Specification 3.0.3 made for operational, convenience. The cause of the LPRM failures has been traced to inadequate post maintenance testing following earlier work associated with these components.. The failed components were repairedlreplaced, testing was completed and the RBM returned to operabte status. The safety significance of this event was minor, and the health and welfare of the public was not compromised. The technical aspect of this event will be reviewed with the work group a review of associated work plans and procedures witt be performed, and appropriate changes implemented. Administratively. 'nd guidance dealing with voluntary Technical Specification 3.0.3 entry and guidance dealing with actions to be taken once Technical Specification 3.0.3 has been entered, will be provided, These changes wilt be communicated to appropriate personnel.

NRC FOAM 366 (495)

~'Huu LD LNWQ LL DC$ uv ~v ~~ ta=v urr)~ I ~ IP4 NRC FORM 366A U,S. NUCLEAR REGULATORY COMlVIISSIOil (4.9$ ) +~

XJCENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACIL)TY NAME (1) DOCKET LER NUMBER (6) PAGE (3) 05000 tnlMMl Susquehanna Steam Electric Station - Unit 2 388 97 007 01 2 OF TEXT llfmore spece rc requ red, vse eddhionel copies of HRC Form 366AJ (17)

EVENT DESCRIPTION On October 17, 1997, at 0920 hours0.0106 days <br />0.256 hours <br />0.00152 weeks <br />3.5006e-4 months <br />, with Unit 2 in Condition 1(Power Operation) at100% power, a Technical Specification 3,0.3 entry was voluntarily made.

On October 16, 1997, at 0820 hours0.00949 days <br />0.228 hours <br />0.00136 weeks <br />3.1201e-4 months <br /> Technical Specifications I.imiting Condition for Operation (LCO)

'.1.4.3 ACTION a and 3.3.6 ACTION 60 were entered to perform required surveillances for the Rod Block Monitor (RBM) (EIIS Code: I). The RBM must be removed from service to perform these surveillances. The ACTION of the most limiting Technical Specification states:

"With one RBM channel inoperative, restore the inoperative channel to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and verify that the reactor is not operating on a LIMITINGCONTROL ROD PATTERN; otherwise, place the inoperable rod block monitor channel in the tripped condition within the next hour."

A few hours into the testing, unexpected results were observed and testing was halted to investigate

., these results. Since the RBM remained inoperable, the LCO ACTION remained in effect The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time period expired prior to restarting the surveillance testing. One hour remained before the.

Technical Specificatio'ns ACTION requires that the RBM channel be placed into the tripped condition.

Prior to the expiration of the one hour period, testing was restarted. Since testing had begun, the

, decision was made to voluntarily enter Technical Specification 3.0.3, considering that the completion of the surveillance testing would allow this channel of the RBM to be restored to service. Technical Specification 3.0.3 was entered at 0920 hours0.0106 days <br />0.256 hours <br />0.00152 weeks <br />3.5006e-4 months <br /> on October 17, 1997 and exited at 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br /> on October 17, 1997.

It was determined that the RBM was actually operating as designed, A number of the Local Power Monitors(LPRM) (EIIS Code: I) had a zero volt output to the RBM. The RBM correctly 'ange identified a zero input condition from an LPRM(s) and automatically eliminated it from the averaging circuit. As long as the RBM had more than the required minimum number of 'good'PRM inputs, it continued to function normally.

CAUSE OF EVENT The cause of the unexpected results of the RBM surveillance has been traced to the failure of components in the LPRM output to the RBM. When these components failed, their output to the RBM went to zero volts. 11 LPRMs were identified to have this condition. LPRM output to the Average Power Range Monitor (APRM) (EIIS Code: I), the Oscillation Power Range Monitor (OPRM)

. (EIIS Code:I), and to the plant computer were normal. It has been determined that the cause of the failed components stems from a power supply failure in June of 1997. The power supply had been replaced and outputs to the APRM and computer were checked, but not the outputs to the RBM. The post maintenance testing following the power supply replacement was not adequate, and is considered a root cause of the event.

NRC FORM 366A (4-()5)

tNJQ l4 4 o oQ

~ ~ h NRc.roRM 3eeA U.S. NUCLEAR REGULATORY COMMISSION l I4-'QS)

XZCENSEE EVENT REPORT (LEE)

TEXT CONTINUATION FACILITY NAME I1) DOCKET LER NUMBER le) PACE I3)

YEAN IhL 05000 NLlM46R HUM46R Susquehanna Steam Electric Station - Unit 2 388 97 007 .01 3 OF 5 TEXT /Ifmore speceis reqv/red. use edu'one/ copies of NRC Farm 866AJ {17)

Technical Specification 3.0.3 was voluntarily erltered when the inoperable channel of RBM was not in the tripped condition following the expiration of allowable time limit of Technical Specification 3.1A.3 ACTION (a). In order to perform the operability testing, the RBM can not be in the tripped condition.

The root cause of the Technical Specification 3,0.3 entry is an administrative omission in the current Technical Specifications. Improved Technical Specifications contain provisions to perform operability testing on inoperable equipment without entry, into a shutdown action statement. The decision to

'nter Technical Specification 3.0.3 is discvssed in greater detail below.

REPORTABILITY/ANALYSIS This Licensee Event Report is being made per 10 CFR 60.73(a)(2)(i)(B), in that NUREG 1022 requires the reporting of any entiy into Technical Specification LCO 3.0.3.

Technical SpecTiication 3.0.3 was entered to allow completion of surveillance testing of one channel of the RBM. As previously noted, one channel of the RBM was removed from service to perform

.surveillance testing. During that testing, unexpected results were obtained. The time to evaluate these results and then complete the testing was going to exceed the time allowed by Technical Specifications. Since completion of the svrveillance testing wovld allow the RBM to be restored to operable status, the decision was made to resume testing and a Technical Specification 3.0.3 entry

, was made when Technical Specification 3,1.4.3 ACTION (a) expired. This decision was made after considering the following alternatives:

1. Suspend testing of the RBM. Place the affected channel of the RBM in the tripped condition to satisfy the LCO ACTION. Enter 3.0.3 and activate the RBM channel to allow testing to resume.

2. Reduce power to 30% of Rated Thermal Power. The RBM is not required to be operable, and LCO 3.1.4.3.a does not apply.

3. Allow testing of the RBM to continue. This wovld mean that compliance with the LCO ACTION would not be maintained. As a result, entry into Technical Specification 3.0.3.

At the time this event occurred, option 1 and 2 were viewed by Operations as presenting an increased risk to nuclear safety. Option 3, the option chosen, was considered to be the least challenging to Operations, and to be within our authority as a licensee. Option 2 challenged the operator to manipulate reactor power, while option 1 required the surveillance work to be halted, delaying the restoration of the RBM, and vltimately resulting in a Technical Specification 3.0,3 entry anyway. Therefore, from strictly a safety perspective, Operations felt that Option 3 was the best option.

The above rationale was reconsidered in response to questions raised by the NRC concerning the appropriateness of entering Technical Specification 3.0.3. A review of the bases for Technical NRC FORM 366A I4 Qa)

HLJV LD, LOAD LC ~ QO NRC FORM 366A U.S. NUCLEAR REGULATORY CCMMISSIOI6 (4-96)

LICENSEE EVENT REPORT (LER)

~

TEXT CONTINUATION FACiL)TYNAME {l) DOCKET LER NUMBER (6) PAGE i3)

I N 05000 NLWOel NVMIBl Susquehanna Steam Electric Station - Unit 2 388 97 007 01 4 OF 5 TEXT Iifmore spece is rerruired,'lse eddic'ooel copies of HRC Form 36'O'AI (17)

Specification 3.0.3 states in part; "The purpose of this specification is to delineate the time limits for placing the unit in a safe shvtdown CONDITION when plant operation cannot be maintained within the limits for safe operation defined by the Limited Conditions for Operation and its ACTIbN requirements. It is not intended to be used as an operational convenience which permits (routine) voluntary removal of redvndant systems or components from service in lieu of other alternatives that would not result in redundant systems or components being inoperable." ln this case, we could have placed the subject RBM channel in the trip condition to meet the ACTION Statement. The requirement and prerequisite of the surveillance could have been re-established at which point Technical Specification 3.0.3 could have been entered to allow the testing. If a sitvation similar to this were to occur in the future, taking the Technical Specification ACTION as described would be

'roper course of action,'roperly balancing compliance and risk issues.. Additional guidance will be provided to shiff supervision as an aid in dealing with voluntary entry into Technical Specification LCO 3.0.3. This guidance will deal with removal of redundant equipment from service and with failure to meet LCO ACTION requirements.

Once entered, Technical Specification 3,0.3 requires action to be taken'to place the affected unit in STARTUP and HOT SHUTDOWN stating in part, within one hour action shall be taken to place the

'units in a OPERATIONAL'ONDITIONin which the specification does not apply by placing it, as

'pplicable in:

at least STARTUP within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> at least HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />...,"

Technical Specification LCO 3.0.3 was entered at 0920 hours0.0106 days <br />0.256 hours <br />0.00152 weeks <br />3.5006e-4 months <br />. The LCO was cleared at 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br />.

This was four hours and fifty minutes into the LCO, leaving two hours and ten minvtes for the vnit to

'~, be in STARTUP had any further problems been encountered. No power reductions were made during this time period. Throughout this period, shift supervision maintained oversight on the activities associated with Clearing the RBM problems, and had reasonable assurance that the LCO would be cleared before the allowed time to be in STARTUP expired. There was no procedvral guidance on specific actions that should have been taken, specific to a time frame, to ensure compliance with the ACTION time limits, PP&L believes it is important that we have very clear expectations associated with actions we intend to take once Technical Specification 3.0.3 is entered.

At no time during this event was the ability of the plant to safely shutdown or the health and welfare of the public compromised. The significance of this event from a safety standpoint was minor. The other channel of the RBM was available throughovt this period to provide rod block protection, as well as the APRMs to provide core protection in the event of a power transient.

In accordance with NUREG 1022, Supplement 1, the required submission date of this report was determined to be November 17, 1997.

Nile FORM 366A i4.95)

NRCiFORM 366A U,S. NUCLEAR REGULATORY COMMISSION (4.OG)

LICENSEE EVENT REPORT (LEE)

TEXT CONTINUATION FACILlTYNAME (1) DOCKET LER NUMBER (6) PAGE (3)

H 05000 'LIM6ER ~ani Susquehanna Steam Electric Station - Unit 2 388 97 007 - 01 5 OF 5 TEXT (llmora spacais required, usa additional copies of NRC Form 366AI (17)

CORRECTIVE ACTIONS r

Improved Technical Specif)cations addresses this type situation by providing allowance for operability testing without entering a shutdown action statement LCO. PP&L's Improved Technical Specification submittal is in review by the commission.

I A Technical SpecTiication change request to the current Technical Specifications has been submitted to the NRC to extend the LCO ACTION statement allowable time for one RBM channel inoperable from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to seven days. Improved Technical Specrf(cations also reflects the lengthened ACTION time limits.

The failed components identified in the LPRMs were repaired/replaced.

The following actions are scheduled to be completed:

, A review of the technical aspects of the event with the involved maintenance work group stressing the importance of comprehensive post maintenance testing.

~ A review of work plans and procedures associated with the LPRMs, APRMs, and RBMs to determine and implement satisfactory methods of ensuring that all outputs from the LPRMs are sufficiently tested following work activities.

~ Evaluate resultslconclusions of above review for generic applicability to other systems.

~ Provide dear procedural guidance dealing with voluntary entry into Technical Specification LCO 3.0.3.

~ Provide clear procedural guidance dealing with actions to be taken by shift supervision once Technical Specification LCO 3.0.3 has been entered.

Communicate these changes to the appropriate personnel via training.

ADDITIONALINFORMATION Past similar events: None Entries into Technical Specification 3.0.3 have been reported on numerous occasions, although none of the previous reports were a result of a similar condition.

Failed Component: None LER written for Technical Specification 3.0.3 entry, the failed components were not the reason for submitting this report.

NRC FORM 3GGA (4.()5)

Hub La lusts La'ia us ~v ~~ taco urr ice. rl f 0+tC R4fd r ~ oo George J. Kuczynski PAL urces, Inc.

General Meagerusquehanna Two North Ninth Street Allentown, PA 181 01-1179 Susquehanna Steam Electric Station P.O. Box 487, 8e vlcc, PA 18803 Tet.717542.3120 Fax 717442.1949 November 17, 1997 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-137 Washington, DC 20555 SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-388/97-007-00 PLA - 4804 FILE R41-2 Docket No. 50-388 License No. NPF-22 Attached is Licensee Event Report 5%88/97-007-00. This event is being reported pursuant to the guidance of NUREG 1022, per 10CFR50.73(a)(2)(i)(B), for an entry into Technical Specification 3.0.3. The Technical Specification 3.0.3 entry was made voluntarily to allow completion of operability testing of one channel of the Rod Block Monitor. The operability testing was completed in a timely manner, the Rod Block Monitor was restored to operable status, and the Limiting Condition for Operation was cleared.

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G. J. uczynski

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General Manager - Susquehanna SES Attachment Mr. H. J. Miller cc: Mr. Kenneth M. Jenison Regional Administrator Sr. Resident Inspector U. S. Nuclear Regulatory Commission U. S. Nuclear Regulatory Commission 475 Allendale Road P.O. Box 35 King of Prussia, PA 19406 Berwick, PA 18803-0035