ML20043G313

Forwards Addl Info Re Pressurizer Surge Line Thermal Stratification & leak-before-break Evaluation & Nonproprietary Suppl 3 to WCAP-12247, Supplementary Assessment... & Proprietary Suppl 3 to WCAP-12248

ML20043G313
Person / Time
Site:	Comanche Peak
Issue date:	06/15/1990
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19298E149	List: ML20043G313 ML20043G323 ML20043G332
References
TXX-90212, NUDOCS 9006200146
Download: ML20043G313 (4)

Text

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.; 1 enemmuseamma MM Log # TXX-90212 I7 File # 10010 (clo) 903.6

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Ref. # 10CFR50.34(b) 1UELECTRIC '4 June 15, 1990 W.J.Cahm  !

Larcuene nce l' resident i U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 ,

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)

DOCKET NOS. 50-445 AND 50-446 ADDITIONAL INFORMATION IN SUPPOR1 0F PRESSURIZER SURGE LINE THERMAL STRATIFICATION ANO .

LEAK-BEFORE-BREAK EVALUATION REF: 1) TU Electric letter logged TXX-89228 from William J. Cahill, Jr.

to NRC, dated May 1, 1989 l

2) TU Electric letter logged TXX-89765 from William J. Cahill, Jr.

to NRC, dated October 24, 1989 '

3) TV Electric letter logged TXX-89832 from William J. Cahill, Jr.

to NRC, dated December 12, 1989

4) NRC letter from C. Grimes to William J. Cahill, Jr., dated i May 15, 1990 Gentlemen:

On May 1,1989, TV Electric submitted, by reference (1), a plant-specific evaluation of the effects of thermal stratification on the Comanche Peak i Unit 1 Pressurizer Surge Line and its ability to satisfy leak-before-break criteria. TV Electric subsequently provided several submittals in response to l NRC questions and requests for clarifying information on the thermal l stratification plant specific evaluation and leak-before-break qualification. i This letter is submitted in response to an NRC request for additional information presented by reference (4). The requested information is provided in two attachments and two enclosures.

As this submittal contains information proprietary to Westinghouse Electric Corporation, it is supported by an affidavit signed by Westinghouse, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of 10CFR2.790.

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l0't 9006200146 900615  % MO b l lM DR ADOCK0500g3 i g g fgp s >64 MX) North Olwe. Street LB 81 Dallas. Texas 7201

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TXX-90212 Page 2 of 2

. - Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosure in accordance '

with 10CFR Section 2.790 of the Commission's regulations.

Correspondence with respect to the proprietary ~ aspects of the Application for Withholding or the supporting Westinghouse Affidavit should reference CAW 90- .

044 and should be addressed to R. A. Wiesemann, Manager of Regulatory &

Legislative Affairs, Westinghouse Electric Corporation, P. O. Box 355, Pittsburgh, Pennsylvania 15230-0355.  ;

If there are any questions, please contact H. A. Marvray at (214) 812-8296.

r b Sincerely, a _

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Illiam J. Cah 11, Jr.

HAM /daj Attachment 1 - Responce to NRC Request for Additional Information Attachment 2 - Westinghouse authorization letter, CAW-90-044, Proprietary -

Information Notice, and accompanying Affidavit Enclosure 1 - 5 copies of WCAP-12248 Supplement 3,"A Supplementary Assessment of Leak Before Break for the. Pressurizer Surge Lines of Comanche Peak Unit 1" (PROPRIETARY)

J Enclosure 2 - 5 copies of WCAP-12247 Supplement 3, "A Supplementary '

o Assessment of Leak Before Break for the1 Pressurizer l- Surge Lines of Comanche Peak Unit 1" (NON-PROPRIETARY) c - Mr. R. D. Martin, Region IV, w/o enclosures and-attachments Resident Inspectors, CPSES (3), w/o enclosures and attachments 7

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' Attachment'I to TXX-90212  :

Page 2 of 2 1

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L NRC Request:

3) -The assumptions ~ used in the " leak-before-break" analysis should be consistent with the assumptions used to show compliance with the ASME Section III Code.- The " leak-before break" analysis should include'the ,

g loading resulting from the combination of pressure, deadweight, thermal-u expansion (including thermal stratification with a differential. >

L temperature of 3200F), and safe shutdown earthquake loads. The corresponding leakage-flaw size for this loading _in the analysis should' be .;

based on " Case B" in Table 5-7 of WCAP-12248.

TU Electric Response:  :

3) The NRC concerns associated with the Surge Line leak-before-break qualification are addressed by Enclosures one and two which provide Supplement 3 to WCAP-12248 (Proprietary) and WCAP-12247 (Non-Proprietary) ,

respectively, i

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p Attachment I to TXX-90212 d Page-1 of 2 5

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Response to NRC Request for Additional Information -

NRC Request:,

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1) Describe the measures in ' place that will" prevent the pressurizer-to-hot -

leg temperature difference from exceeding the value assumed in WCAP-12248 during all modes of plant operation.

TU Electric Response:

1) CPSES procedures for plant heatup from cold shutdewn to hot standby and plant cooldown from hot standby to cold shutdown provide explicit j instructions to the operator that maximum pressurizer to reactor coolant 1*

L system hot leg temperature differential of .3200F should not be exceeded.

This specific instruction provides sufficient assurance that the pressurizer-to-hot leg temperature difference of 3200F is not exceeded.

NRC Request:

2) If the pressurizer-to-hot leg temperature difference cannot be maintained below the 3200F value used in WCAP-12248 at all times ~, provide an

]i analysis of the effects of this potential excess on the thermal stratification loads defined in WCAP-12248 and verify continued compliance 7 with Section III of the ASME Boiler and Pressure Vessel Code.

.TU Electric Response:

2) CPSES procedures currently provide sufficient assurances th~at'the pressurizer-to-hot leg temperature differential of 3200F is not.

exceeded.- Furthermore, in response to previously expressed NRC concerns Lthat sufficient data is necessary to confirm that ;he existing. design transients utilized in the plant-specific evaluation are conservative, TV Electric,' by reference (3) committed to implement a Surge Line temperature  !

. monitoring program. The Surge Line temperature monitoring data collected to date has verified the effectiveness of CPSES procedures to maintain the 1 pressurizer-to-hot-leg temperature differential below 3200F, TU rs Electric's commitment to collect Surge Line temperature data remains as.

stated by reference (3).  :

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