ML20235T841

Forwards Response to Generic Ltr 88-14, Instrument Air Supply Sys Problems Affecting Safety-Related Equipment. Each air-operated safety-related Valve Verified to Fail to Required Safety Position During Sys Review & Test Program

ML20235T841
Person / Time
Site:	Davis Besse
Issue date:	02/22/1989
From:	Shelton D TOLEDO EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-88-14, NUDOCS 8903080495
Download: ML20235T841 (5)

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'.h-1 TOLEDO EDISON 1

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' A Centenor Energy Company l

DONAU) C. SHELTON vo. enment_eumor (419]249-2300

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. Docket Number 50-346 License Number NPF.l l

Serial Number 1-861

, February 22,.1989-United States Nuclear Regulatory Commission Document Control Desk Washington, D. C.

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Subject:

Toledo Edison's Response to Generic Letter Number 88-14 Gentlemen On August 24, 1989, Toledo Edison (TE) received Nuclear Regulatory Commission

,(NRC) Generic Letter 88-14, " Instrument Air Supply System Problems Affecting Safety-Related. Equipment", dated August 8, 1988 (Log Number 2674). The Generic Letter requested that licensees review NUREG-1275, Volume 2,

" Operating Experience Feedback Report - Air System Problems", and perform a design and operations verification of their Instrument Air System. Generic Letter Number 88-14 identified three specific areas to be reviewed and verified:

1.

The quality of Instrument air versus manufacturer's recommendations, 2.

The adequacy of practices, procedures, and training to ensure that equipment vill function as intended, and

3. 'The adequacy of the entire system design, including accumulators, to perform its intended function.

In addition, Generic Letter Number 88-14 requested a discussion of the licensee's program for maintaining proper instrument air quality. Toledo

. Edison has completed a review of NUREG-1275 and performed the verifications requested by the Generic Letter. As a result of these efforts, TE concludes that the design, installation, maintenance, testing,~ training, and procedures for. Davis-Besse's Instrument Air System are adequate to ensure that air

. operated safety-related equipment should riot fail to perform their intended safety function because of air ~ supply system problems. The attachment contains a summary of the verification prccess as well as TE's method for maintaining proper instrument' air quality.

8903080495 890222 PDR ADOCK 05000346

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L THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652 [

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Please contact Mr.-R. V. Schrauder, Nuclear Licensing Manager, at (419)

.249-2366 if there are any questions.

Very trul yours,.

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.cc P. M. Byron, DB-1-NRC Resident Inspector

~'A. B. Davis, Regional' Administrator, NRC Region ~III-T. V. Vambach,-DB-1 NRC Senior Project Manager-1.-

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Dock 3t Nurber 50-346-

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Licensa Nu;b;r'NPF *

. Serial Number'1-861 Enclosure.

Page'l-d RESPONSE TO GENERIC LETTER 88-14, o

" INSTRUMENT AIR. SUPPLY SYSTEM PROBLEMS AFFECTING. SAFETY-RELATED EQUIPMENT",

.FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT NO. 1 Attached is Tohdo Edison's response to Generic Letter 88-14, " Instrument Air Supply System Problems Affecting Safety-Related Equipment". This letter is submitted pursuant-to 10CFR50.54(f).

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By

~Mb D. Cl Shelton, Vice President, Nuclear Sworn and subscribed before me this February 22, 1989

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Notary hublic, State of Ohio LAURiE A. HlNKLE Notary Public. Stata of Ohio My Ccmmission Expires May 15,1991

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Dock 0t Nu ber 50-346:

• 7, I Lic;nso Number NPF-3 Serial Number 1-861 Attachment Page 1 RESPONSE TO GENERIC LETTER NUMBER 88-14 NRC Item 1 Verification by test that actual instrument air quality is consistent with'the manufacturer's recommendations for individual components served.

Toledo Edison's Response Air quality for the Davis-Besse Instrument Air System is maintained such that

. it exceeds the quality specified by Standard ISA-S7.3 of the Instrument Society of America.

Standard ISA-57.3 specifications are used for air quality standards rather than manufacturer's recommendations because manufacturers typically only specify that air for their components be " clean, dry, and oil-free".

(See NRC Item 4).

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

Toledo Edison's Response An extensive air system modification (MOD 87-1062) was completed during the Fifth Refueling Outage that ended in December of 1988. A new larger capacity air compressor was installed and one of the systems' existing compressors was designated an emergency compressor. As a result of.these changes, procedures and practices required to operate and maintain the air system were reviewed for adequacy and revised as necessary.

System retraining was conducted as was a valk through validation of system procedures and lineups, including those procedures that address a loss of instrument air. Toledo Edison believes these actions are adequate to ensure that safety-related equipment vill function as intended on a loss of instrument air.

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

Toledo Edison's Response Each air-operated safety related valve was verified to fail (on a loss of instrument air) to its required safety position during the System Review and Test Program (SRTP) conducted in 1986 - 1987. Additionally, safety related accumulators were verified to be sized correctly and to perform as required during a loss of instrument air and other design-basis events.

Docket Number 50-346 License Number NPF-3 Serial Number 1-861 Attachment Page 2 NRC Item 4 Provide a discussion of the licensee's program for maintaining proper i

instrument air quality.

Toledo Edison's Response Air quality of Davis-Besse's Instrument Air System is maintained as part of scheduled Preventive Maintenance. The system's devpoint is checked three times weekly.

Particle size and oil content are maintained through the use of an air dryer after-filter. The differential pressure across this filter is checked daily and the elements are inspected quarterly, and replaced if necessary.

Davis-Besse air quality standards exceed those specified in Instrument Society of America Standard ISA-S7.3, which are:

1)

Dewpoint: at least 18'F below the minimum local ambient temperature, not to exceed 35'F 2)

Particle size:

three (3) microns or less 3)

Oil content zero.

Davis-Besse maintains an Instrument Air System devpoint of at least minus 35'F and the system's after-filter elements are sized to remove air particles larger than 0.07 microns. In addition, these filters vill remove any oil that might enter the system.

(Note: The air compressors used at Davis-Besse are designed to provide oil-free air.)

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