ML17348A266

Forwards Update to 890310 Response to Generic Ltr 88-14, Instrument Air Supply Sys Problems Affecting Safety-Related Equipment. Sys Upgrade Sent Out for Equipment,Const & Engineering Estimates

ML17348A266
Person / Time
Site:	Turkey Point
Issue date:	05/30/1990
From:	Harris K FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-88-14, L-90-197, NUDOCS 9006050341
Download: ML17348A266 (13)

Text

ACCELERATED DIS UTION DEMONS TION SYSTEM g ~

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9006050341 DOC.DATE: 90/05/30 NOTARIZED: NO DOCKET g FACIL:50-250 Turkey Point Plant, Unit 3, Florida Power and Light C 05000250 50-251 Turkey Point Plant, Unit 4, Florida Power and Light C 05000251 AUTH. NAME AUTHOR AFFILIATION HARRIS,K.N. Florida Power & Light Co.

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

SUBJECT:

Forwards update to 890310 response to GL 88-14, "Instrument Air Supply Sys Problems Affecting Safety-Related Equipment."

DISTRIBUTION CODE: A048D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: OR/Licensing Submittal: Equipment Qualify'.cation NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 0 PD2-2 PD 1 0 EDISON,G 1 1 INTERNAL: NRR/DET/EMEB 9H 1 1 NRR/DET/ESGB 8D 1 1 OC~ 1 0 OGC/HDS2 1 1 G~LE 0 1 1 RES/DSIR/EIB 1 1 EXTERNAL: LPDR 1 1 NRC PDR 1 1 NSIC 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 12 ENCL 9

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pp P.O. Box14000, Juno Beach, FL 33408-0420 NAY 30 1990 L-90-197 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 Instrument Air Supply System Problems Affecting Safet -Related E i ment Generic Letter 88-14 Generic Letter (GL) 88 14r "Instrument Air Supply System Problems Affecting Safety-Related Equipment," issued by the NRC on August 8, 1988, requested that licensees review NUREG-1275, "Operating Experience Feedback Report Air System Problems," Volume 2, and perform a design and operations verification of the Instrument Air System.

In letter L-89-63, dated March 10, 1989, FPL provided an initial response to GL 88-14, along with a schedule for the completion of the remaining action items. Attached is an update of the previously submitted information. FPL considers the design and operations verification of the instrument air system, as required by GL 88-14, to be completed. Action items identified through this effort will be pursued in accordance with the schedules provided.

Should there be any questions regarding this information, please advise.

Very truly yours, K. N. arris Vice resident Turkey Point Nuclear Plant KNH/DRP/DWH/rat attachment cc: Stewart D. Ebneter, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, Turkey Point Plant SOO+05O34i SOO53O i PDR P

ADOCK 05000250 O4' PDC ~l an FPL GrouP comPanY

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ATTACHMENT TURKEY POINT UNITS 3&4 GENERIC LETTER 88-14 INTRODUCTION Turkey Point suffered degradation of safety-related components in July of 1985, due to contamination of the plant's instrument air system. Ref: LER 250/85-21; IE Inspection Report 85-40, 1/2/86; SSFI Report 85-32, 10/7/85. Since then, FPL has aggressively pursued improved system performance via upgraded maintenance and operating procedures, additional training of licensed and non-licensed operators, and reviews of system design and capacity. Specific actions related to require-ments of GL 88-14 are delineated.

SCOPE A list of air operated valves was developed, based on the Total Equipment Data Base listing. This list has been verified complete by comparison to instrument air system drawings as marked up during the Select System Program walkdown.

From this complete list, those valves relevant to GL 88-14 were selected. The selection was based primarily on the safety classification of the valves. The final test list comprises eleven (11) unit-common valves and two hundred and thirty-two (232) unit-specific valves.

REQUIREMENTS/STATUS The requirements of the verification are quoted from GL 88-14 below, with the status of related activities:

1. "Verification by test that actual instrument air quality is consistent with the manufacturer's recommendations for individual components served."

1a. Seventeen (17) air quality sample points were selected to obtain sam-ples from diverse locations throughout the instrument air system.

1b. An independent laboratory analyzed the air quality samples taken from the seventeen (17) selected air quality sample points. Each sample was determined to be within specification when compared to the indus-try standards used by the independent laboratory. Particulates were measured in milligrams per cubic meter of air sample. When compared to an industry standard of five (5) milligrams per cubic meter, none of the samples tested exceeded 0.5 milligrams per cubic meter.

1c. FPL Engineering provided the air quality requirements for the valves on the test list. These requirements were based on the individual

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valve manufacturers'ecommendations.

1 d~ A comparison of the analyzed air quality samples to individual manu-facturer recommended air quality requirements demonstrated that the actual instrument air quality is consistent with the manufacturer's recommendations. With respect to particulate micron size, manufact-urer recommendations were compared to installed filter regulators.

As a result of this comparison, FPL engineering recommended that fil-ter regulators be installed on air operated valves that do not cur-rently have filter regulators and that filters be replaced in various filter regulators with a different size filter. Cost estimates are being prepared for the recommended filter regulator enhancements.

The cost estimates are scheduled to be presented to the FPL Change Review Team (CRT) by August 3, 1990.

2. "Verification that maintenance practices, emergency procedures, and train-ing are adequate to ensure that safety-related equipment will function as intended on loss of instrument air."

2a ~ Maintenance Selected maintenance procedures related to the availability of instru-ment air were reviewed. Many of these were created or revised since the 1985 events, specifically to upgrade the reliability of safety-related functions. These improvements were controlled via Adminis-trative Procedure O-ADM-705, Guidelines for the Analytical Based Pre-ventive Maintenance Program. Application of this guiding procedure to the instrument air system is discussed later in this attachment.

Several additional improvements were identified during the latest re-view and appropriate procedure changes have been implemented.

2b. Emer enc Procedures FPL's procedure for loss of instrument air is an off normal operating procedure (0-ONOP-013) rather than an emergency procedure. This off normal procedure was reviewed with regard to the concerns expressed in SOER 88-1, and validated on the training simulator; to date, no changes have resulted from this review and validation.

With the exception of restoration of instrument air inside contain-ment (if possible), the emergency operating procedures do not address or take credit for instrument air availability. A success path is still available if an air operated valve is manipulated and "Response Not Obtained." Alternative action is then indicated, which is usually manual operation or operation of a manual valve.

2c ~ Training All operators receive specific training on the off normal procedure for instrument air, and systems training on plant air systems. Li-censed operators also receive simulator training on complete and par-tial loss of instrument air, as well as the more traditional simula-tions of individual component failures.

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Conclusion Based on the above information, maintenance practices, emergency procedures, and training are considered adequate to ensure that safety-related equipment will function as intended on loss of instrument air.

3. "Verification that the design of the entire instrument air system including air or other pneumatic accumulators is in accordance with its intended func-tion, including verification by test that air-operated safety-related com-ponents will perform as expected in accordance with all design-basis events, including a loss of the normal instrument air system. This design verifica-tion should include an analysis of current air operated component failure positions to verify that they are correct for assuring required safety func-tions."

3a. Procedure changes, and in some cases plant modifications, were made for thirty-four (34) of forty-eight (48) air operated valves identi-fied as utilizing accumulators. These actions were taken to ensure proper testing of the check valves associated with the accumulators for backleakage during a loss of instrument air.

Eight (8) air operated valves utilizing accumulators are part of the steam dump system and serve no safety function. Six (6) air operated valves utilizing accumulators are part of the Component Cooling Water System supplying the Emergency Containment Coolers. These six (6) valves are not required to change position to per form a safety func-tion during a loss of instrument air. Therefore; surveillances for backleakage during a loss of instrument air will not be performed on the check valves associated with the accumulators on these fourteen (14) air operated valves.

3b. The failure positions for the valves on the test list were verified by test. Credit was taken for valves tested under the Inservice Test-ing (XST) Program and for valves tested via post maintenance testing.

3c. FPL Engineering compiled the design failure positions for valves on the test list. This information was based on reviews of design docu-mentation.

3d. A comparison between the as-built failure positions and the plant de-sign verified that the current failure positions are correct for as-suring required safety functions. No discrepancies were identified during this comparison.

4. "Xn addition to the above, each licensee/applicant should provide a dis-cussion of their program for maintaining proper instrument air quality."

Turkey Point has an extensive program for ensuring that proper instrument air quality is maintained. This program consists of proper operation, sur-veillance, maintenance and ongoing design review of the system to ensure it functions as intended. These four areas are discussed below.

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Operation of the system is controlled by plant procedures which control the configuration of the system and the operation of system components. These procedures ensure that the normal system configuration from the compressors through the dryer after filters is such that compressor discharge air is cooled, the liquid water and any oil is removed, the air is dried, and par-ticulates are removed prior to admitting the air to the distribution por-tion of the system. Component redundancy allows for maintenance without compromising air quality.

Surveillance Plant procedures direct various surveillance activites to identify degra-dation of air quality. Plant Operator logsheets require (1) blowing down of drain traps upstream of the air dryers (to check for excessive moisture, indicative of trap sticking), (2) checking for proper operation of the after cooler automatic drain traps, and (3) blowing down the dryer after filter drains to check for moisture downstream of the dryers. The dryer control panels are equipped with alarm lights for control malfunctions and high outlet dew point.

Plant procedures require dryer outlet dew point to be tested weekly. Out of specification dew point requires action (notification of the system eng-ineer, increased surveillance, troubleshooting per plant procedure, and blow-down of system drains). The extent of this required action is determined by the dew point.

Plant procedures also call for monitoring of system performance and relia-bility by the system engineer. This is accomplished through frequent system walkdowns to identify potential problems. The system engineer also performs other systematic activities to prevent system failure, predict system degra-dation, correct system problems, and thereby improve system reliability.

Maintenance The Instrument Air System maintenance program has been developed in accord-ance with the Analytical Based Preventive Maintenance (ABPM) program. The goal of the program is to support the plant to preserve the operability and safety of plant system, structures, and components. The ABPM program pr i-oritizes plant systems based on the need for improvement in system mainten-ance practices. For a particular system, analytical methods are used to generate a set of preventive maintenance (PM) procedures, and the period-icity under which each PM task is to be performed.

The Instrument Air System maintenance program was among the first to be up-graded under the ABPM program. The resulting PM procedures have ensured that instrument air system components are properly maintained at appropriate intervals. This in turn, ensures that the instrument air system continues to supply clean, dry, high quality air as designed..

The compressors currently in use are diesel driven, 100 5 oil free, rotary screw units. These have provided a reliable source of compressed air. The original plant electric compressors have been removed from service due to concerns about Emergency Diesel Generator loading. The diesel compressors

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and air-cooled after coolers provide a source of compressed air independent of both onsite and offsite electrical power . Maintenance of these units is performed by the vendor.

To further ensure that proper instrument air quality is provided to safety-r elated air operated valves, planned maintenance (PM) instructions will be developed, as necessary, that will require the filters in instrument air filter regulators to be inspected on a regular basis. This action is sche-duled to be completed by December 7, 1990.

Desi n Review To further enhance confidence in instrument air quality, a system upgrade prospect was presented to the FPL Change Review Team (CRT). The system up-grade included new electric air compressors to replace those currently un-used, new air dryers, on-line dew point monitoring, and fewer unit cross-ties. The system upgrade has been sent out for equipment, construction, and engineering estimates. The FPL CRT will review the instrument air system upgrade prospect when the cost estimates have been developed.

Inter faces between the instrument air system and other systems which may result in contamination of the instrument air system are minimized by de-sign. Interfaces with the service air system and supervisory air to the fire protection system dry piping were reviewed for possible elimination.

These interfaces are necessary and will remain in place.

~Sammar Considerable effort has gone into upgrading and expanding the operations, surveillance and maintenance practices regarding instrument air at Turkey Point, particularly since the occurrences described in LER 250/85-21. To date these efforts have included: (1) improvements to the plant operating procedures to ensure the system and its components are operated per design, (2) improvements to surveillance practices to ensure that component mal-functions or system problems are identified in a timely manner, and (3) improvements to the preventive maintenance program to ensure that system components are properly maintained, with the goal of preventing failures.

The result of these efforts has been to ensure that proper instrument air quality will be maintained at Turkey Point. In addition, efforts to further improve and refine these practices are continuing, as evidenced by the de-scriptions of the actions and ongoing programs described herein.

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