ML17229A361

LER 97-007-00:on 970502,reactor Coolant Pump Oil Collection Sys Was Outside App R Design Bases.Identified Leak Sites Were Repaired & Mods to RCP Oil Collection Sys to Capture Any Future Leakage from areas.W/970529 Ltr

ML17229A361
Person / Time
Site:	Saint Lucie
Issue date:	05/29/1997
From:	Frehafer K, Stall J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-97-0137, L-97-137, LER-97-007, LER-97-7, NUDOCS 9706040241
Download: ML17229A361 (8)

Text

CATEGORY 1 REGULATORY IViFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9706040241 DOC.DATE: 97/05/29 NOTARIZED: NO DOCKET FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 AUT3',.k>AMk AUTHOR AFFI'..:A ION FREH:;."ER,K.W. Florida Power & Light Co.

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

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 97-007-00:on 970502,reactor coolant pump oil collection sys was outside App R design bases. Identified leak sites were repai.ed & mods to RCP Oil Collecon Svs to capture any future leakage from areas.W/970529 1rr.

DISTRIBUTION CODE: ZE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc. E NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-3 PD 1 1 WIENS,L. 1 1 R

INTERNAL: ACRS 1 1 EOD$4,PD/RAB .. 2 2 Y

AEOD/SPD/RRAB 1 1 FII E CENTER 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 LITCO BRYCEiJ H 1 1 NOAC POORE,W. 1 1 NOAC QUEENER,DS 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 E

N NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORDANIZATION 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 EiVCL 25

florida Power & Light Company, 6501 South Ocean Drive, Jensen Beach, fL34957 May 29, 1997 L-97-0137 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 No. 50-335 Reportable Event: 97-007 Date of Event: May 2, 1997 Reactor Coolant Pump Oil Collection System 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 JASIKWF Attachment cc: Regional Administrator, USNRC Region II Senior Resident Inspector, USNRC, St. Lucie Plant 970b04024i 970529 PDR ADOCK 05000335 S PDR lllllllllllllllllllllllillllllllillllll an fPL Group company

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED SY OMB No. 3160C 104 EKFmES 04130rss (4-95)

ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATO INFORMATION COLLECTION REOUEST: 60.0 HRS. REPORTED LESSON LGVlNEO ARE INCORPORATED INTO THE UCENSING PROCESS AND F BACK TO BIOUSTRY. FORWARD COMMENTS REGARDING BURDEN ESTIMAT

'LICENSEE EVENT REPORT (LER) TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH IT% F33I U.S. NVCLEAR REGULATORY COMMISSION. WASHINGTON, DC 20665<001 ANO TO THE PAPERWORK REDUCTION PROJECT (3160<leer, OFHCE 0 (See reverse for required number of MANAGEMENTAND BUDGET, WASHINGTON, OC 20503.

digits/characters for each block)

FACIUTY NAME11l DOCKET NI3IISIFI (21 PAGE 131 ST LUCIE UNIT 1 05000335 1 OF4 TITLE (41 Reactor Coolant Pump Oil Collection System Outside Appendix R Design Bases FACIUTY NAME DOCKET NUMBER OAY YEAR SEOUENTIAL REVISION MONTH NUMBEA NUMBER DAY YEAR St. Lucle Unit 2 05000389 FACIUTY NAME DOCKETNUMBOl 2 97 97 007 0 5 29 97 05000 OPERATINO MDDE (9) 20.2201(b) 20. 2203 (a) (2) (v) 50.73(a) (2) (i) 50.73(a)(2)(viii)

POWER LEVEL (10) 100 20.2203(a)(2)(I) 20.2203 (a) (3) (ii) 50.73(a)(2) (iii) 73.71 OTHER 20.2203 (0) (2) (iii) 50.36(c)(1) 50.73(a) (2)(v) Specify bl Abetrect below or in NRC Form 366A 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii)

NAME TELEPHONE NUMBER Snelude Ares Cedei K. W. Frehafer, Licensing Engineer (561) 468-4284 R ~ABLE ggi4$9pV REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER TO NPROS CAUSE SYSTEM COMPONENT MANUFACTUREA TO NPADS tI'rM+EL 9~%P~k%

MONTH OAY 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 typewiitten lines) (16)

On May 2, 1997, St. Lucie Unit 1 was at 100 percent power, and St. Lucie Unit 2 was in Mode 6 and defueled for a refueling outage. An outage inspection of the Unit 2 Reactor Coolant Pumps (RCPS) identified minor external oil leakage at the upper and lower RCP'motor oil reservoir locations that was not captured by the RCP Oil Collection System. Appendix R Section III.O requires that the RCP Oil Collection System be designed to collect oil from all potential RCP oil leakage sources.

The cause of this event was due to design deficiencies of the RCP Oil Collection System. Corrective action include repairs to identified leak sites, and modifications to the RCP Oil Collection System to capture any future leakage from these areas.

NRC FOAM 366 (4.96)

NRC FORM 388A U 8, NUCLEAR RMUIATORYCOMMISSIO I4-95)

LZCENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION St. Lucie Unit 1 05000335 2 OF 4 97 007 0 TEXT (ifmore speceis required, use edditionel copies of NRC Form 366AJ I17l On May 2, 1997, St. Lucie Unit 1 was at 100 percent power, and St. Lucie Unit 2 was in Mode 6 and defueled for a refueling outage. An outage inspection of the Unit 2 Reactor Coolant Pumps (RCPs)

[EIIS:AB:P] identified external oil leakage not captured by the RCP oil collection system.

The existing RCP Oil Collection System design consists of three oil drip enclosures and five drip pans on each reactor coolant pump motor. A gravity drain piping system is provided to transport any accumulated oil from these devices to a 225 gallon oil collection tank. The tank is vented and provided with a flame arrestor with a magnetic liquid level gage to provide local indication of oil in the tank. The collection devices are designed to collect oil leakage from the following potential leakage sources:

1. The lift oil system,

2. all flanged connections on the oil coolers & circulating oil piping,

3. oil fill and drain lines, and, 4, oil level instrumentation piping.

The Unit 2 RCP inspection'oted oil leakage at both the upper and lower RCP motor oil reservoir locations.

The investigation into the source of the oil from the lower reservoir identified minor weepage from the "pie pan" (lower oil reservoir top access covers)/RCP shaft seal area. Because of the small amount of oil leakage, it is not possible to positively confirm whether the source is from the RCP shaft seal or the "pie pan" covers. The investigation into the source of leakage from the upper oil reservoir identified a leaking RCP bearing resistance temperature detector (RTD) penetration fitting on the motor top hat, which allowed oil to collect on top of the RCP motor housing and run down the side of the motor.

These leakage sites are at atmospheric or low pressures and are located above the normal upper and lower reservoir oil levels. However, these locations can potentially leak small amounts of oil due to the oil splash caused by the rotating components inside the oil reservoirs. It was therefore determined that the design of the RCP Oil Collection System was deficient in that not all potential oil leakage sources have provisions for collection.

The original RCP Oil Collection System design did not consider the these component parts to be potential leakage sources because their locations are above the normal operating oil reservoir level. Additionally, the lower reservoir operates only at a slightly positive pressure and the upper reservoir operates at atmospheric pressure. The potential for leakage due to oil splash was not considered in the original design. Therefore, no design features were provided to collect oil from these locations.

NRC FoRM 366A I4 95I

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSI I4-96I LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION St. Lucie Unit 1 05000335 3 OF 4 97 007 0 TEXT 'ilfmore speceis required, use edditional copies of NRC Farm 366Ai I17)

The RCP Oil Collection System design is required to meet the requirements of 10CFR50 Appendix R Section II.O, which states that "the system shall be so designed, engineered, and installed that failure will not lead to fire during normal operation or design basis conditions and that there is reasonable assurance that the system will withstand the Safe Shutdown Earthquake. Such collection systems shall be capable of collecting lube oil from all potential pressurized and unpressurized leakage sites in the reactor coolant lube oil systems." However, the St. Lucie RCP Oil Collection System design is deficient in that not all potential oil leakage sites have provisions for being collected. Therefore, it was determined that this condition was reportable because the RCP Oil Collection System was outside of the Appendix R Section III,O design bases.

Because Unit 1 and Unit 2 have similar RCP motors and oil collection systems, the design deficiencies associated with the upper oil reservoir top hat area and the lower oil reservoir shaft seal/"pie pan" area are applicable to both Units 1 and 2. The following assessment was made to determine the fire potential resulting from any uncollected oil at these locations.

The identified leakage sites were assessed in order to characterize any postulated leakage and resultant fire potential The potential leakage sites are either unpressurized or only slightly pressurized and are located

~

above the normal operating level of the oil reservoirs. Any postulated leakage would be from the oil splash caused by the rotating components inside the oil reservoirs. Therefore, oil escaping from the reservoir would not be sprayed (atomized), but would result in only minor drips of uncollected oil The fire potential

~

of such leakage is minimal; if a drip were to come in contact with a hot surface (temperature over the ignition temperature) it would not accumulate; the drop would burn but not support further combustion. If it comes in contact with a cool surface it could locally accumulate, but would eventually migrate to the floor. Oil landing on the floor will be directed to floor drains based on floor slope. Lubricating oil on the floo or in the sump is not subject to ignition because the floor is a vast heat sink which will maintain the oil at a low temperature and prevent it from reaching its ignition point. Therefore, the potential for a fire resulting from minor oil leakage from these locations is not considered credible.

In addition, RCP motor upper and lower oil reservoir levels are trended and reviewed on a monthly basis to ensure that RCP lube oil leaks are identified during plant operation. Although changes in the containment temperature and pressure can cause small variations in indicated RCP oil reservoir level, any appreciable los of RCP lube oil is detectable. There have been no safety significant RCP lube oil leaks identified on either Unit 1 or 2.

NRC FORM 368A l4.95I

NRC FORM 366A U.S. NUCLEAR RMULATORYCOMMISSIO I4-95I LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION YEAR SEQUENTIAL REVISION St. Lucie Unit 1 05000335 4 OF 4 97 007 0 TEXT Itfmore spaceis required, use additional copies of NRC Form 366AJ I17)

Continued operation of Unit 1 is justified based on the above discussion and the following additional information. Currently, the System Engineer has concluded that no significant oil leaks are present in any of the Unit 1 RCPs, based on data collected over the last six months. Additionally, the inspection of the .

RCPs, during the recent Unit 1 Short Notice Outage (SNO) on April 19, 1997, did not identify any significant external oil leaks. An oil film on the 1A1 RCP and platform was noted. Even though the precise source of this oil film is not known, it is evident that the existing minor oil leakage has not come in contact with an ignition source in containment. Thus, it is reasonable to assume that further leakage from the same location would also not come in contact with ignition sources, and that a fire in containment from existing potential leakage sources is not likely.

1 ~ The uncollected oil was cleaned up.

2. Work orders were issued to repair the identified leaking penetrations and to resolve leaks on the lower reservoirs.

3. A step was added to the RCP General Inspection and Repair Master PWO task description to address proper installation of the lower reservoir "pie pan" covers.

4. The RCP instrumentation removal/reinstallation Master PWO task description will be revised to ensure adequate provisions for installing and sealing penetration fittings.

5. PCM 97-025 was implemented on the Unit 2 RCP Oil Collection System to ensure that any future oil leakage from the mechanical penetrations would be captured by the system.

6. Similar modifications will be implemented on the Unit 1 RCP Oil Collection System during the Fall 1997 refueling outage.

None.

NRC FORM 368A I4-95I

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