TXX-4644, Forwards Rev B to LOCA & Seismic Analysis, in Response to 841109 Request for Addl Info Re Containment Purge & Vent Valve Operability.Addl Info,Including Table Re Valve Operator Torque Margins,Also Encl

Forwards Rev B to LOCA & Seismic Analysis, in Response to 841109 Request for Addl Info Re Containment Purge & Vent Valve Operability.Addl Info,Including Table Re Valve Operator Torque Margins,Also Encl

ML20138P458
Person / Time
Site:	Comanche Peak
Issue date:	12/16/1985
From:	Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Noonan V NRC - COMANCHE PEAK PROJECT (TECHNICAL REVIEW TEAM)
Shared Package
ML20138P461	List: ML20138P473 TXX-4644, Forwards Rev B to LOCA & Seismic Analysis, in Response to 841109 Request for Addl Info Re Containment Purge & Vent Valve Operability.Addl Info,Including Table Re Valve Operator Torque Margins,Also Encl
References
TXX-4644, NUDOCS 8512260125
Download: ML20138P458 (4)

Text

Log # TXX-4644 TEXAS UTILITIES GENERATING COMPANY File #$0010 SKYWAY TOWEM e 400 NORTH OLIVE EFTMEET. L.B. el e DALLAN, TEXAN 78301 '19

.*MOa5?fn".S December 16, 1985 Director of Nuclear Reactor Regulation Attention: Mr. Vince S. Noonan, Director Comanche Peak Project Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION DOCKET NOS. 50-445 AND 50-446 CONTAINMENT ISOLATION DEPENDABILITY

Dear Mr. Noonan:

Attachment 1 and enclosure 1 are provided in response to NRC letter of November 9, 1984 requesting additional information concerning containment purge and vent valve operability.

Should you have additional questions in this matter, please contact this office.

Very truly yours, 4/716 W. G. Counsil BSD/grr Attachment - 39 copies Enclosure - 4 copies c - A. Vietti-Cook .

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i l 8512260125 851216 7 NA i PDR ADOCK 05000445 A PDR A oms:ou or rexAs vrrursss etscrasc courAur

ATTACHMENT 1 TO TXX-4644 Response to letter from B. J. Youngblood (NRC) to M. D. Spence (TUGCo):

1. The postulated design basis accident which results in the worst case. conditions relative to load predictions.

Response

The postulated DBA which results in the worst loading on.the 18 inch Posi-Seal International vent valves is a LOCA as described in FSAR Section 6.2 and 15.6.

~2. If demonstration of valve operability is by analysis, the basis upon which the torque coefficients were determined.

Response

The bases upon which the torque coefficients were determined are hydrodynamic torque converted-to aerodynamic torque for compressible fluid flow, actuator torque, and frictional resistance. The correlation between hydrodynamic and aerodynamic torque coefficients is verified by data published in ISA transaction 68-923.

3. The effects of installation configuration, disc rotation, etc. on load determinations.

Response

The effects of valves' installation configuration, disc rotation, and piping layout are detailed in the section " Determination of LOCA Torques," and Appendix "A" of the LOCA and Seismic Analysis

(#349775L-001) (See Item 4, below).

4. A stress analysis demonstrating structural integrity of internal parts.and interface hardware for the valves and valve operators under the combined seismic'and DBA/LOCA conditions.

Response

LOCA'and Seismic Analysis (#34977SL-001), Rev. B is enclosed.

5. The valve operator torgt! margins (i.e., the difference between the 1 valve operator torque available and those combinations of torque l developed that tend to oppose valve closure), at all angles of ,

operation, and the rating of the valve operators. l Response:  ;

See Table 1, (attached).

l

- _ . - - - , , . . , , . - - , _ . - , _ . ,, ,, , ~,n,, ,

6. The operability status of the 48 inch valves (e.g., if the 48 inch valves will be locked closed during operating mode 1, 2, 3 and 4, they need not be' addressed in responding to item 1 through 5 above; however, TUGCo must formally confirm that these valves will be locked closed in responding to this letter).

Response

The 48 inch valves will be locked closed in modes 1, 2, 3 and 4 in accordance with Technical Specification 3.6.1.7.

1 i

l 1

TABLE-1 DISC ANGLE. SPRING VADPBC-09 (NON-PREFERRED) VADPBC-10 (PREFERRED)

FROM CLOSED TORQUE (1) NET TORQUE TORQUE MARGIN NET TORQUE . TORQUE MARGIN POSITION (IN-LB) 0F FLOW (2) (IN-LB) 0F FLOW (2) (IN-LB)

(IN-LB) (IN-LB) 65 5614 1213 6827 5331 10945 60 5326 273 5599 2524 7850 50 4894 -1494 3400 -474 4420 40 4685 -2167 2518 -1/52 2933 30 4643 -2391 2252 -2318 2325 20 4875 -2469 2406 -2460 2415 10 5426- -2486 2940 -2485 2941 NOTES:

_ (1) Obtained from pages C-4, C-6, C-8, C-10, C-12 and C-14 by interpolation. Minimum value selected.

(2) Net closing torque = Aerodynamic torque minus frictional resistance. Positive.

values indicate closing torques, negative values indicate torques which tend to open the valve. These values are obtained from pages B-8, B-9, B-28, B-29, B-47, B-48, C-4, C-6, C-14, C-16 for non-preferred flow, and B-18, B-19, B-20, B-38, B-39, B-55, B-56, C-8, C-10, C-12 for preferred flow. Minimum value selected.

w_-.