ML20042D670

Responds to NRC Generic Ltr 89-19, Resolution of USI A-47,Safety Implication of Control Sys in LWR Nuclear Power Plants. Plant Design Meets Criteria of Generic Ltr 89-19 for Automatic Steam Generator Overfill Protection

ML20042D670
Person / Time
Site:	South Texas
Issue date:	03/08/1990
From:	Rosen S HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-A-47, REF-GTECI-SY, TASK-A-47, TASK-OR 900408, GL-89-19, ST-HL-AE-3397, NUDOCS 9003260306
Download: ML20042D670 (4)

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- TheLLight cHouston o mpLighting anySouth

& Power Texas Project Electric Generating Station ' P. O. Boa 289 Wedsworth.Temu 77483 March 8, 1990 ST HL AE-3397 File No.: G3.8 10CFR50 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555  ;

South Texas Project Electric Generating Station Unite 1 and 2 NRC Generic Letter 89-019:

Request for Action Related to Resolution of Unresolved Safety Issue A 47 " Safety Implication of Eqntrol Systems in LWR Nuclear' Power Plants" Pursuant to 10CFR 50.54(f)

Houston Lighting and Power (H14P) has reviewed'the subject Generic .

Letter and conducted a review of the South Texas-_ Project Electric Generating l Station (STPEGS) design for automatic protection from Feedwater overfill  !

events and found that no design changes-are warranted.

The Generic Letter identifies Westinghouse-designed,PWR Plants as- I falling into three categories.- STP is a " Group I" plant when compared to the ;j guidelines provided in the Generic Letter. STP has been designed with the i goal of ensuring that control system _ failures will not prevent automatic or- l manual initiation and' operation of any safety equipment required to trip.the l plant or to maintain the plant in a safe shutdown following:any " anticipated 'f operational occurrence" or " accident". STP accomplishes this by the use~of j independence between safety and non safety systems or by providing qualified-isolation devices between safety and'non safety systems.

STP has a safety grade overfill protection. scheme based on steam generator high water level in a 2 out-of-4 initiating;1ogic. - The system ,

isolates main feedwater (MFW) by closing the MFW isolation, control and bypass a valves and tripping the MFW pumps. The plant procedures and Technical -

l Specifications provide periodic verification'of this overfill protection.  ;

This meets the guidelines of the Generic Letter for the basic design of g the overfill protection scheme. ,

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. Houston Lighting & Power Company ST HL- AE- 3397 File No.: G3.8 Page 2L .

The issue of independence' of control and protection for Steam Generator level is addressed in the STP UFSAR, SER, and UFSAR Questions and Responses .

-(Q & R)'to the NRC. As stated in these documents the MFV control. system is powered by a separate power source from the protection system. In addition, the control system-is physically mounted in independent cabinets from the- 3 protection system. The issue of cable routing is.also addressed. The-protection channels are safety grade and therefore physically independent from the non safety related control wiring, in accordance with the Reg. Guide 1.75 requirements for fire protection.

Fcilures of individual sensorst losses of power.to inverters, losses-of-power to individual protection, control,-and auxiliary; process cabinets,.or breaks in common instrument lines all result in events which are bounded by. '

FSAR Chapter 15 analyses. _Therefore, the TSAR adequately bounds'the consequences of these' fundamental failures.

In conclusion, the South Texas design meets the criteria of_ Generic  ;

-Letter 89 019 for' automatic steam generator overfill protection.

If you should have any questions on this matter,.please contact .

Mr. M. A. McBurnett at (512) 972-8530 or myself at (512) 972-7138.. l S. L.=Rosen  ;

Vice President Nuclear. Engineering and Construction I

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ST HL AE 3397 Houston Lighting & Power Company South Texas Project Electric Generating Station File No.: G3.8 g p888 3 cc:

Regional Administrator, Region IV Rufus S. Scott, Nuclear Regulatory Commicsion- Associate General Counsel 611 Ryan Plaza Drive, Suite 1000 Houston Lighting & Power Company Arlington, TX 76011 -P. O. Box 61867=

Houston, TX 77208 George Dick, Project Manager  :

U.S. Nuclear-Regulatory Commission INPO Washington, DC 20555 Records Center .

j 1100 Circle 75 Parkway _a J.-1. Tapia Atlanta, GA 30339-3064'

. Senior Resident Inspector c/o U. S, Nuclear Regulatory Dr. Joseph M. Hendrie Commission 50 Be11 port Lane -t' P. O. Box 910 Be11 port. NY 11713 Bay City,-TX 77414

• D. K, Lacker- '

J. R. Newman, Esquire- Bureau of Radiation Control Newman & Holtzinger, P.C. Texas Department of Health 1615 L Street, N.W. 1100 West 49th Street Washington, DC 20036 Austin, TX 78704' l D. E. Ward /R. P. Verret Central Power & Light Company P. O. Box 2121 Corpus Christi, TX 78403 J C. Lanier Director of Generation City of Austin Electric Utility 721 Barton Springs Road Austin, TX 78704 R. J Costello/M, T. Hardt i

). City Public Service Board i

P. O, Box 1771-San-Antonio, TX 78296 Revised 12/15/89-L4/NRC/-

- ATTACHMENT ST HL-AE 339 7  :

A PAGE' f 0F .I

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UNITED STATES OF AMERICA -

. NUCLEAR REGUIATORY COMMISSION -

In the Matter' -)

. )- . .

Houston Lighting & Power - )- Docket Nos. 50-498  :

Company, et al., ) 50 499  :{

,)- 9 South Texas Project )

Units-1 and 2- )-  ;

' AFFIDAVIT .

S. L. Rosen being duly sworn, hereby deposes and'says that'he'is Vice- (

President, Nuclear-Engineering and Construction, of. Houston Lighting'&. Power-Company;;that he is duly authorized to sign and file with the Nuclear Regulatory, .

Commission the attached response to NRC Generic Letter 89-019; is familiar.with 1 the content thereof; and that the matters set forth therein are true and correct

-to. the best of his knowledge and belief. -i S. LMosen -

Vice President -l Nuclear: Engineering and Construction >

d Subscribed and sworn to before me, a Notary Public~in and for The State

, of Texas this 7

• day of M u d , 1990. ",

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)#M' MIN"!E 00N2A' E3 ary Public in an5 for the-State of Texas

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