ML20246M970

Revises 890206 Response to Generic Ltr 88-14,Item 6 Re Instrument Air Problems.Rev Covers NRC Request for Addl Info Re Rapid & Gradual Loss of Instrument Air Testing of safety- Related Components

ML20246M970
Person / Time
Site:	Comanche Peak
Issue date:	05/11/1989
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-88-14, TXX-89191, NUDOCS 8905190313
Download: ML20246M970 (4)

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""" 9 Log '# TXX-89191 1 . File # 10035 r C Ref. # Generic Letter 88-14

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.May 11,.1989 p W.J.Cahm Esecutive Vke hesident p

U.L.S. Nuclear Regulatory Commission S ' Attn: Document' Control Desk Washington,.D. C. 20555 fi

SUBJECT:

COMANCHE. PEAK STEAM ELECTRIC STATION (CPSES)

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DOCKET NOS. 50-445 AND 50-446 fl , NRC GENERIC LETTER 88-14:

? INSTRUMFNT AIR SUPFLY SYSTEM _ PROBLEMS AFFECTING

. SAFETY-RELATED. EQUIPMENT 3

H REF: TU Electric letter TXX-89052, . dated February 6,1989 Mr. W. J. Cahill, Jr. to V 5. NRC

. Gentlemen:

letter'TXX-89052, dated February 6,1989, responded to NRC TU Electric, Generic Letterby(GL)- 88-14, " Instrument Air Supply System Problems Affecting Safety-Related Equipment", and the recommendations in NUREG-1275, Volume 2.-

In recent discussions, the NRC staff requested additional information regarding:ra components-(pid see itemand gradual 6 on loss of 11 page 10:and instrument air testing of TXX-89052). of safetyrevised The following related response to item 6 provides the requested additional information:

(6) NUREG-1275,-Volume 2, Item 5 (Page 59)

All operating plants should be required to. perform gradual loss of instrument

. air system pressure tests.

Gradual instrument air system pressure loss tests (preoperational testing) have revealed deficiencies in safety system equipment including common mode failure potential. A number of such failures have not been within the envelope of'FSAR accident analyses. Accordingly, it is recommended that all plants verify that credible gradual IA system bleeddown events will not result in unanalyzed and/or unacceptable conditions. If plants have performed the Regulatory Guide 1.68.3 bleeddown tests previously, no additional bleeddown testing'should be required unless significant system modifications have been made subsequent to such testing. Additionally, plants which have never performed a rapid bleeddown test (e.g., such as was required in Regulatory Guide'li80), should be required to perform such testing.

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1. O North Olive Street LB81 Dallas, Texas 75201

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l TXX-89191 May 11, 1989 Page 2 of.3 CPSES Response TV Electric will conduct loss of instrument air system pressure tests as recommended by item 5 of NUREG-1275, Vol. 2 for the safety related air operated components. The following CPSES information is provided regarding the commitment to Regulatory Guides and Criteria for loss of instrument air tests:

A) The CPSES Instrument Air System is not a safety-related system, and hence NRC Regulatory Guides 1.68.3 or 1.80 are not applicable (refer to FSAR Sections IA(B) for Reg. guides 1.68 and 1.80, and also refer to FSAR Q/R's 0432.12 and 0432.26).

B) TV Electric will perform loss of instrument air tests (rapid and gradual) on safety related, air-operated valves, dampers, accumulators and their check valves. These tests will be performed on a component by component basis as part of testing their respective safety related functions. These tests will be conducted utilizing the following test methods and acceptance criteria and will be completed prior to fuel load of each unit.

(1) Test Methods:

a) Isolate air operated component (s) to be tested from air supply, b) For rapid loss of air test, open vent valve rapidly to bleed down affected component (s).

c) For gradual loss of air test, crack open vent valve to slowly bleed down affected component (s).

(2) Acceptance Criteria:

a) During rapid and gradual loss of air test, safety related air operated components (valves and dampers) should return to fail safe position (i.e., the position assumed in the safety analysis).

b) During rapid and gradual loss of air Test, accumulator check valves should close to maintain accumulator pressure (i.e.,

safety rela +ed accumulators should retain sufficient pressure to perform the design function of the affected component)

4 TXX-89191 May 11, 1989 Page 3 of 3 C) Procedures for conducting the loss of instrument air tests (rapid and gradual) will be revised or developed prior to performance of the applicable test.

Sincerely,

~ 4 7 William J. ill, Jr.

MCP/vid Attachments c - Mr. R. D. Martin, Region IV Resident inspectors, CPSES (3) i t

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- ttachment to TXX-89191 May 11, 1989 .

Page 1 ofil UNITED STATES OF AMERICA.

_. NUCLEAR REGULATORY COMMISSION l

'In the Matter of Texas Utilities' Electric Company Docket Nos. 50-445

.50-446 (Comanche Peak Steam Electric Station, Units 1 & 2)_

,. AFFIDAVIT William J.' Cahill, .Jr. being duly sworn, hereby, deposes and says that he. is Executive Vice President, Nuclear of TV Electric, the Applicant herein; that

1 he is duly authorized to sign and file with. the Nuclear Regulatory Commission

- this' revised response to NRC Generic Letter 88-14; that he is familiar with -

'the content thereof;'and that the matters set forth therein are true and correct,to.the best of his knowledge, information'and belief.

Til Ti ain' ~J. ~Cfill , J r. [ /

STATE OF TEXAS- ~)

) Notary Seal COUNTY OF DALLAS. )

' Sub cribeA and sworn to before me, a Notary Public in and for .

yy/(A'fffjE,onthis /n' day of Wa , 1989.

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(L - W Notary PutWic My commission expires: //-/d8b .

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