ML17229A314

LER 97-004-00:on 970402,refueling Machine Was Operating in Manner Prohibited by TS Due to Original Design of Refueling Machine Bypass Feature Conflicting W/Ts Requirements. Eliminated Overload Cut Off Limit bypass.W/970430 Ltr

ML17229A314
Person / Time
Site:	Saint Lucie
Issue date:	04/30/1997
From:	Frehafer K, Stall J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-97-120, LER-97-004, LER-97-4, NUDOCS 9705060087
Download: ML17229A314 (6)

Text

REGULATOR CATEGORY lg INFORMATION DISTRIBUTION SYSTEM (RIDS) iACCESSZQP NBR:9705060087 DOC.DATE: 97/04/30 NOTARIZED: NO DOCKET ¹ FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 AUTH. NAME AUTHOR AFFILIATION FREHAFER,K.W. Florida Power & Light Co.

STALL,J.A. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION 8 Document Control Branch (Document Control Desk)

LER 97-004-00:on 970402,refueling machine was operating in C

SUBJECT:

manner prohibited by TS due to original des'gn of refueling machine bypass eacure conflicting w/TS requirements.

Eliminated overload cut off limit bypass.W/970430 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

E 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 PD2-3 PD 1 1 WIENS,L. 1 1 INTERNAL: ACRS 1 1 EOE~L.SB -RA 2 2 AEOD/SPD/RRAB 1 1 ILE CEN 1 1 NRR/DE/ECGB 1 1 NRR DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DET/EIB 1 1 RGN2 FILE 01 1 1 D EXTERNAL: L ST LOBBY WARD 1 1 4

LITCO BRYCE,J H 1 1 0 NOAC POORE,W. 1 1 NOAC QUEENER,DS 1 1 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 LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 25 ENCL 25

Florida Power & Light Company, 6501 South Ocean Diive, Jensen Beach, FL34957 April 30, 1997 L-97-120 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Re: St. Lucie Units 1 and 2 Docket Nos. 50-335 and 50-389 Reportable Event: 97-004 Date of Event: April 2, 1997 Operation of Refueling Machine in a Manner The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Very truly yours, J. A. Stall Vice President St. Lucie Plant JAS/KWF Attachment cc: Regional Administrator, USNRC Region II Senior Resident Inspector, USNRC, St. Lucie Plant 9705060087 970430 PDR ADQCK 05000335 gggg 8 PDR

<<'V'z>> )t/

~

IIIIIIIIIII IIIIIIIIIIIIIIIIIIIIIIIIIII an FPL Group company

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED SY OMS NO. 3) 600106 EXFSLES 06)30)SS (4.96)

ESllMATED BURDEN PER RESPONSE TO COMP) Y W)TH THIS MANDATO INFORMATION COLLECTION REQUEST: 60Al HRS. REPORTED LESSON LEARNED ARE INCORPORATED INTO THE UCENSINO PROCESS AND F BACK TO WOUSTRY. FORWAIE) COMMENTS REOAROINO BURDEN ESTIMAT jdxCENSEE EVENT REPORT (LER) TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH IT% F33)

U.s. NUCLEhfl REGIAATORY COMMISSION. WASHINGTON, DC 206660001 AND To THE PAPERWORK REOUCllON PROJECT 131600104), OFRCE 0 (See reverse for required number of MANAGEMENTAND BUOOET, WASHINGTON, DC 20603.

digits/characters for each block)

FACIUTY NAME il) DOCKET NLWISBl 12) PAOE 13)

ST LUCIE UNIT 1 05000335 1 OF 3 llTLS ti)

Operation of Refueling Machine in a Manner Prohibited by Technical Specifications FACIUTY NAME DOCKETNUMBER MONTH DAY SEQUENT)AL flEVI SION DAY YEAR NUMBER NUMBER St. Lucie Unit 2 05000389 FACIUTY NAME DOCKET NUMBER 04 02 97 97 004 0 30 97 05000 OPERATIN0 MODE (9) 20.2201(b) 20.2203(e) (2)(v) 50.73(a) (2) (i) 50.73(a)(2)(viii)

POWER mVEL (10) 100 20.2203(e)(2)(i) 20.2203(a) l3)(ii) 50.73(a)(2)(iii) 73.71~

OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2) (v) Speci(Y In Abstract below or In NRC Form 36BA 20.2203(a) (2Hiv) 50.36(c)(2) 50.73(a)(2)(vii)

NAME TELEPHONE NUMBER Sndude Aree Code)

K. W. Frehafer, Licensing Engineer (561) 468-4284 REPORTABLE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER TO NPROS TO NPROS MONTH DAY YEAR EXPECTED YES SUBMISSION (If yes, complete EXPECTED SUBMISSION DATE). X No DATE (15)

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

On April 2, 1997, St. Lucie Units 1 and 2 were operating at 100 percent reactor power. As a result of reviewing operating experience concerning the original design and past operation of the refueling machine, a deficiency was identified that represented a failure to satisfy Technical Specification requirements regarding the manipulator crane overload cut off limit.

The cause of this event was due to the original design of the refueling machine automatic bypass feature, which conflicts with the Technical Specification requirements for the manipulator crane.

The corrective action is to eliminate overload cut off limit bypass by modifying the refueling machine overload protection circuitry. This modification has been implemented for Unit 2 and is planned for Unit 1.

NRC FORM 388 (4.96)

NRC FOAM 386A U.S. NUCLEAR AEOULATOAYCOMMNSI Ie-II6I LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION ST LUCIE UNIT 1 05000335 2 OF 97 004 0 3'EXT

/ifmore spece is required, use edditionel copies of NRC Form 366AJ I17I

'On April 2, 1997, St. Lucie Units 1 and 2 were operating at 100 percent reactor power. Engineering personnel identified a deficiency regarding the operation and design of the refueling machine [EIIS:DA]

during a review of operating experience pertaining to refueling machir.e discrepancies identified at other utilities. The deficiency relates to the automatic bypassing of the hoist [EIIS:DALHOI]overload cutout

[EIIS:DA:IMEC] when the lift is in the hoist box transition area.

Technical Specification 3.9.6 for both'units requires the manipulator-crane (refueling machine) to be OPERABLE with an overload cut off limit of s 3000 pounds. This Limiting Condition of Operation (LCO) is applicable during movement of fuel assemblies or Control Element Assemblies (CEAs) "within the reactor pressure vessel." Technical Specification Surveillance Requirement 4.9.6 for both units requires the manipulator crane to be demonstrated operable, in part, by demonstrating an automatic load cut off when the crane load exceeds 3000 pounds.

The automatic bypassing of the hoist overload cutout when the lifted load is in the hoist box transition area represents a failure to satisfy the Technical Specification requirements regarding the manipulator crane overload cut off limit, This event was caused by the original design of the refueling machine. The automatic bypass feature of the refueling machine overload cut off interlock is a feature that is common on refueling machines provided by Programmed And Remote (PAR), the equipment Vendor. Since the design was part of the original refueling machine circuitry, the failure to correctly translate the design into the Technical Specifications is considered an administrative error during 'orIginal plant licensing.

Bases section 3/4.9.6 of the Technical Specifications, as applicable to the automatic overload cut off, describes the intent of the Technical Specification 3/4.9.6 as protec!ing the core internals and pressure vessel from excessive lifting forces in the event they become inadvertently engaged during lifting operations.

During a normal fuel assembly lift the refueling machine hoist is initially only lifting the weight of a fuel assembly (with or without a CEA). In this phase of the lift the fuel assembly is protected by a "fuel only" overload interlock which will automatically stop the hoist when the load cell reaches a predetermined "fuel only" load set point (-1430 pounds). Once the fuel assembly has been lifted into the hoist box, the hoist box starts to lift off of its stops. At this point the weight of the hoist box is added to the total load displayed on the refueling machine indicator. In this latter phase of the lift the "fuel plus hoist box" overload interlock provides the overload protection and will stop the hoist when the load cell reaches a predetermined set point ('2800 pounds). In order to prevent an erroneous overload condition, the refueling

NRC FORM 368A U.S. NUCLEAR RMULATORYCOMMISSI I4.96I

'I LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION ST LUCIE UNIT 1 05000335 3 OF 3 97 004 0 TEXT ilfmore spece is required, use edditionel copies of NRC Form 3M4J I17) machine load monitoring system was designed with an automatic bypass feature which momentarily bypasses the automatic overload circuitry when the lift is transitioning from the "fuel only" region to the "fuel plus hoist box" region. The refueling machine vendor (PAR) has indicated that the overload bypass is in effect (i.e., blocks any automatic overload trip) for app'roximately 6" of fuel assembly/hoist box travel.

The bypass feature is an original design feature which is common on PAR refueling machines used throughout the industry.

The intent of the overload interlock Technical Specification requirement as described in the Technical Specification bases is to protect the core internals and reactor vessel from the effects of lifting a stuck fuel assembly. The bypass feature is momentarily engaged at a point in the lift where the fuel assembly has been completely removed from the core region and has been retracted into the hoist box. At this point in the lift there is no further potential for contact between the fuel assembly being lifted and the core internals or pressure vessel, thus there is no opportunity for the lift to result in damage to core internals or the pressure vessel, Although the intent of the Technical Specifications bases have been satisfied by the time the bypass is engaged, the refueling machine is still technically "within the reactor pressure vessel."

Therefore, this constitutes a condition which is prohibited by Technical Specifications, and is reportable under 10 CFR 50.73(a)(2)(i)(b).

There is no safety significance associated with the momentary automatic bypassing of the hoist overload cut off. At the point in the fuel lift that the bypass feature is engaged, there is no opportunity for the lift t result in damage to the core internals or the pressure vessel because there is no further contact between the assembly being lifted and the core internals or pressure vessel. Additionally, the fuel assembly has been retracted within the hoist box at this time. The intent and bases of Technical Specification 3.9.6 have been satisfied. Therefore, this condition had no adverse effect on the health and safety of the public.

A modification (PC/M 97021) was implemented on Unit 2 to modify the refueling machine overload protection circuitry such that the fuel plus hoist box overload interlock is active at all times when th hoist motor is engaged in the upward direction.

2. A similar modification will be performed on the Unit 1 refueling machine overload protection circuitry prior to the Fall 1997 Unit 1 refueling outage.

3. An INPO Network entry on this event was made.

None Nhc FoRM 368A I4-96I

I' 4