ML17352A078

Special Rept:On 930610,SJAE SPING-4 Monitor RAD-3-6417 Out of Svc for More than Seven Days Due to Failed Detector. Temporary Moisture Separator Being Installed,In Area of Lower Ambient Temp Which Is Expected to Reduce Moisture

ML17352A078
Person / Time
Site:	Turkey Point
Issue date:	06/24/1993
From:	Plunkett T FLORIDA POWER & LIGHT CO.
To:	Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
L-93-162, NUDOCS 9306300081
Download: ML17352A078 (5)

Text

ACCELERATED DOCUMENT DISTRIBUTION SYSTEM REGULRTOY INFORNATION DISTRIBUTIOI+YSTEM (RIDE)

ACCESSION NBR:9306300081 DOC.DATE: 93/06/24 NOTARIZED: NO DOCKET FACIL:50-'250 Turkey Point Plant, Unit 3, Florida Power and Light C 05000250 AUTH. NAME AUTHOR AFFILIATION PLUNKETT,T.F. Florida Power 6 Light Co.

RECIP.NAME RECIPIENT AFFILIATION EBNETER,S,D, , Region 2 (Post 820201)

SUBJECT:

Special rept:on 930610,SJAE SPING-4 monitor RAD-3-6417 out of svc for more than seven days due to failed detector.

Temporary moisture separator being installed, in area of D lower ambient temp which is expected to reduce moisture.

DISTRIBUTION CODE: IE22D COPIES RECEIVED LTR I ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident pt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D

PD2-2 LA 1 1 PD2-2 PD 1 1 RAGHAVANFL 1 1

.D INTERNAL: ACNW 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB NRR/DE/EELB 1,

1 1

1 AEOD/ROAB/DSP NRR/DE/EMEB 2

1 2

1' NRR/DORS/OEAB ,1 1 NRR/DRCH/HHFB 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRIL/RPEB 1 1 NRR/DRSS/PRPB 2 2 NR~R~DSS SPLB 1 1 NRR/DSSA/SRXB 1 1 EG FILE 02 1 1 RES/DSIR/EIB 1 1 GN ILE Ol 1 1 EXTERNA'L: EG&G BRYCEFJ.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHYFG.A 1 1 NSIC POOREFW. 1 1 NUDOCS FULL TXT 1 1 D

D D

NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTEI CONTACI'HE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEEDt TOTAL NUMBER OF COPIES REQUIRED: LTTR -30 ENCL 30

r'.0. Box 029100, M<amr, FL, 33102-9100 FPL JUN 2 4 1993 L-93-162 10 CFR 550.36 Stewart D. Ebneter Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta St.r= N War Suite 2900 Atlanta, GA 30323 Mr. Stewart D. Ebneter:

Re: Turkey Point Unit 3 Docket No. 50-250 Special Report Steam Jet Air Ejector Radiation Monitor SPING Out of Service Greater Than Seven Da s In accordance with Technical Specificati:ons 3.3.3.3 and its associated action statement, the attached Special Report is submitted. The special report addresses the Steam Jet Air Ejector Radiation Monitor RAD-3-6417 being out of service for.

greater than seven days.

Should there be any questions on this information please contact us.

Very truly yours, fp gag't/

T. F. Plunkett Vice President Turkey Point Nuclear TFP/CLM/cm Attachment cc: USNRC, Document Control Desk, Washington D.C.

Ross C. Butcher, Senior Resident Inspector, USNRC, Turkey Point Plant 9306300081 930624 PDR ADOCK 05000250 8 PDR an FPL Group company

Z,-93-162 Attachment Page 1 of 3 SPECIAL REPORT STEAM JET AIR EJECTOR (SJAE) RADIATION MONITOR OUT OF SERVICE PURPOSE:

Technical Specification 3.3.3.3, Table 3.3-5, Instrument 19c, Condenser Air Ejectors, refers to Action Statement 34, which=requires the submission of a Special Report to the NRC if the SJAE High Range Noble Gas Effluent Monitor is inoperable for greater than seven days. The Technical Specification requires the report to describe the actions taken,. the cause of the inoperability, and the plans and schedule for restoring the system to operable status.

Back round:

Florida Power and Light's (FPL) Turkey Point Nuclear Units 3 and 4 are equipped with steam jet air ejectors to remove condensible gases from the main condensers. The air ejector takes suction from-the main condenser and discharges the removed gases directly to atmosphere. The condenser air ejector discharge is monitored for radioactivity, which would indicate leakage from the reactor coolant system into the secondary system (steam generator tube leakage) . The originally installed monitor (tag number R-15) provides an annunciated alarm in the control room. To comply with NUREG 0737, FPL installed an additional monitor specifically to monitor the air ejector exhaust for particulates, iodine and noble gases (RAD-~-6417) . These Eberline model SPING-4 monitors were installed in 1984.

The air ejector exhaust is a mixture of air, water, and corrosive (ammonia-based) byproducts of the volatile secondary chemistry control program. The SPING-4 monitor is sensitive to liquid water in the sample stream. Liquid water will damage the detectors, especially the particulate and iodine detectors, which use paper and charcoal filter elements to accumulate the nuclides of interest.

FPL has encountered difficulties with liquid water in the detectors. Refrigerant chillers were installed to cool the exhaust stream and remove the liquid condensate. While this corrective action stopped the water intrusion problem, the chillers rapidly deteriorated in the corrosive exhaust stream. As a result, they are no longer used. Self-regulating heat tracing was installed on the sample line, to evaporate any liquid water and reduce sample humidity so that condensation would not occur in the 'detector chambers. A gel-cell battery was substituted for the lead-acid a

L-93-162 Attachment Page 2 of 3 battery inside the electronics enclosure of- the monitor, and the enclosure was then sealed. These additional modifications were aimed at eliminating corrosion of the electronics cards and card cage.

A root cause analysis led to three recommendations: (1) replace the self-regulating heat tracing on the sample line outside the monitor with thermostatically controlled heat tracing; (2) insulate the sample line inside the monitor enclosure, and insulate the sample line moisture separator (part of the original installation, but situated in an area with too high an ambient temperature); and (3) mount a thermostatically controlled strip heater on the detector block (approximately 1000 pounds of lead shielding around the detectors) . These recommendations were developed based on information obtained while the plant was at a lower ambient temperature.

EVENT:

At 1425 on June 10, 1993, the Unit 3 SJAE SPING-4 monitor RAD 6417, was declared inoperable due to a failed detector. Concurrent with attempts to repair the monitor, personnel evaluating permanent solutions to this situation were brought together to determine why the problem had arisen again on Unit 3, why the problem had not manifested on Unit 4, and what temporary modification could to restore the operability of the Unit 3 monitor. The be'ffected team determined that water intrusion into the detector chamber was the cause of the failed detector, recommended heating the detector block, and developed a temporary procedure to do so (TP-993). The temporary procedure provided instructions to monitor the effectiveness of the modification to aid in determining whether the scope of PC/M 93-086 was appropriate.

CAUSE AND ACTIONS TAKEN Attempts to repair the monitor, evaluation of the problem, the determination of the best temporary modification, and the development of the temporary procedure took longer than seven days.

Therefore, RAD-3-6417 was inoperable during that period. As required by Technical Specifications, Chemistry personnel implemented the alternative sampling method .(grab samples) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the failure, and continue to sample the stream. No unsatisfactory results have been identified.

L-93-162 Attachment Page 3 of 3 SCHEDULE FOR RESTORATION The temporary modification described above was not successful in eliminating the moisture intrusion into the detector chamber.

A temporary moisture separator is being installed, in an area of lower ambient temperature, which is expected to reduce the moisture intrusion sufficiently,to restore the monitor to operable status.

The condition of the radiation monitor will-be watched closely and evaluated to ensure the effectiveness of the temporary moisture separator. If it performs satisfactorily, a Plant Change/Modification package is expected to be issued by July 16, 1993, for permanent modifications.