ML20012E653

Provides Final Response to Reporting Requirement 2 of NRC Bulletin 88-008, Thermal Stresses in Piping Connected to RCS, for Unit.Nde Requirements of Action 2 Not Considered Applicable to Unit

ML20012E653
Person / Time
Site:	Comanche Peak
Issue date:	03/27/1990
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-88-008, IEB-88-8, TXX-90113, NUDOCS 9004060055
Download: ML20012E653 (4)

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':lllllll' 'llll"ll Log # TXX-90113

'_- j File # 10119 903.6 Q ' Ref. # NRCB 88 08 1SIELECTRIC March 27, 1990 U. S. Nuclear Regulatory Commission Attn Document Control Desk Washington, D, C. 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) c DOCKET NOS 50 445 AND 50 446 FINAL RESPONSE FOR UNIT 1 TO NRC BULLETIN 88 08:

, THERMAL STRESSES IN PIPING CONNECTED TO REACTOR COOLANT SYSTEMS Ref: 1) TU Electric letter. TXX-88766, from W. G. Counsil to NRC, dated October 31, 1988.

2) TU Electric Letter. TXX 89805, fror W. J. C.s.f^', Jr. to NRC, dated November 17, 1989.

Gentlement Reference 1 provided TV Electric's response to Reporting Requirement 1 of NRC Bulletin 88-08'for Units 1 and 2. The TV Electric response identified sections of unisolable piping that are potentially susceptible to the conditions described in the bulletin, Reference 2 provided an interim response for Unit l'to Reporting Requirement'2 of the bulletin. TU Electric's final response to Reporting Requirement 2 for Unit 1 is provided below. For clarity Reporting Requirement 2 and associated Actions 2 and 3 have been restated. The attachment provides the required affidavit. in accordance with the requirement of NRC Bulletin 88-08, that responses be submitted under oath L or affirmation under the provisions of Section 182a. Atomic Energy Act of

1954. as amended.

Reoortino Reauirement 2 Those addressees who determine that there are unisolable sections of piping that can be subjected to stresses from temperse.we stratification -

or temperature oscillations that could be induced b. 'eaking valves and that were not evaluated in the design analysis of the piping shall submit a letter within 30 days of completion of Actions 2 and 3, This letter 1 should confirm that Actions 2 and 3 have been completed and describe the I actions taken.

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9004060055 PDP 900327 O

ADOCK 05000445 PDC

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@ N. Olive Dallas. Texas 75201

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,7 TXX 90113  !

March 27, 1990 1 Page 2 of 3 q 1

l Action 2  :

For any enisolable sections of piping connected to the RCS that may have j been subjected to excessive thermal stresses, examine nondestructively the j welds, heat affected zones and high stress locations, including geometric )

discontinuities, in that piping to provide assurance that there are no existing flaws.

l TV Electric Response to Action 2 Based on crack initiation and propagation analysis for Farley Unit 2 ,

TU Electric and Westinghouse have determined that it is highly unlikely that a crack could be initiated by thermal fatigue during the relatively j short amount of time that Unit i has been hot. Therefore, the j nondestructive examination requirements of Action 2 are not considered  !

applicable to Unit 1.

Action 3 f

Plan and implement a program to provide continuing assurance that l unisolable sections of all piping connected to the RCS will not be subjected to combined cyclic and static thermal and other stresses that l could cause fatigue failure during the remaining life of the unit. This :

assurance may be provided by 1) redesigning and modifying these sections ,

of piping to withstand combined stresses caused by various loads including s temporal and spatial distributions of temperattre resulting from leakage i across valve seats, 2) instrumenting this piping to detect adverse temperature distributions and establishing appropriate limits on  ;

temperature distributions, or 3) providing means for ensuring that .

pressure upstream from block valves which might leek is monitored and does l not exceed RCS pressure.

TV Electric fe3Donse to Action 3 I

TU Electric has implemented a program utilizing the second option, ,

L described by Action 3 above. Resistance Temperature Detectors (RTD's) l have been installed on the unisolable piping sections described in -

reference 1). The RTO's sense pipe temperatures at selected locations on the piping. The output of these RTD's is fed to a data acquisition system. Temperature data is collected by Operations personnel at procedurally specified intervals and is used to develop temperature profiles for evaluation by engineering personnel. Other plant parameters, L such as RCS pressures and temperatures. and system flow rates are also L recorded.

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TXX-90113

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Page 3 of 3  :

l Limits on temperatures and differential temperatures are specified in i procedures. If these limits are exceeded, further engineering evaluations ,

will be conducted and appropriate actions will be taken. The above .'

program is based on monitoring guidelines developed by Westinghouse. The program may be modified in the future to reflect operational experience  :

accumulated by CPSES and Westinghouse.

Installation of the RTO's, Data Acquisition System, and interconnecting  ;

wiring have been completed. Data Acquisition System testing and checkout .

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has been performed and the system was declared operational on March 10, 1990. Documentation of these activities is available for review by NRC inspectors. >

t As required by NRC Bulletin 88 08, Actions 2 and 3 will be completed for  :

Unit 2 prior to Unit 2 initial criticality, and a letter will be submitted pursuant to Reporting Requirement 2 within 30 days of completing Actions 2 and -

3.

Sincerely.

William J. Cahill, Jr.

HAM /vid Attachment c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3)

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Attachment to TXX 90113 i

).' March 27, 1990 Page 1 of 1  !

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UNITED STATES OF AMERICA  ;

t NUCLEAR REGULATORY COMMISSION  :

In the Matter of ) '

) i 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 lead Applicant herein: l that he is duly' authorized to sign and file with the Nuclear Regulatory Commission this Unit 1 final response to NRC Bulletin 88 08: 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, r

. A i L

William J. Epti111,'Jr. // l Executive Vice President, Nuclear e l

STATE OF TEXAS )

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COUNTY OF M AS )  :

er d and swo before me, a Notary Public, on this b day of

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