ML20093J458

Forwards Supplementary Info on IGSCC Weld Insp Results,In Response to Addl Questions Based on Review of Util 840702 Submittal

ML20093J458
Person / Time
Site:	Quad Cities
Issue date:	07/11/1984
From:	Rybak B COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
8928N, NUDOCS 8407300129
Download: ML20093J458 (6)

Text

.

. , Commonwe:lth Edison

/ ) one First National Plaza. Chicago. Ilkno s 7 Addr:ss Reply to. Post Office Box 767

/ Chicago, Illinois 60690 July ll, 1984 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Quad Cities Station Unit 1 Supplementary Information on IGSCC Weld Inspection Results NRC Docket No. 50-254 References (a): B. Rybak letter to H. R. Denton dated March 19, 1984.

(b): B. Rybak letter to H. R. Denton dated July 2, 1984.

Dear Mr. Denton:

In Reference (b), Commonwealth Edison provided a summary of the ultrasonic inspection and repair of the stainless steel welds for Quad Cities Unit 1. Additional questions were raised by members of your Staff upon receipt and review of our submittal. Attached in the form of an enclosure to this letter, is our response to thnse questions.

If you have any additional questions regarding this issue, please contact this office.

One signed original and forty (40) copies of this submittal are provided for your use.

Very truly yours, -

B. Ryba Nuclear Licensing Administrator 1m Attachment cc: R. Bevan - NRR NRC Resident Inspector - Quad Cities 00 8407300129 840711 i 'I PDR ADOCK 05000254 {

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ENCLOSURE QUA0 CITIES UNIT 1 IGSCC WELD INSPECTION RESPONSE TO NRC QUESTIONS ON OUR JULY 2, 1984 SUBMITTAL 8928N i

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o Table 1 Ultrasonic Examination - One Side Access Quad Cities Unit 1 Weld Number Systems Diameter Sida Not Scanned 02AS-F8 Recirculation 28" Valve 02AS-F9 28" Valve 02AS-F14 28" Cast Elbow 02AD-F12 28" Pump 02AD-F9 28" Valve 02AD-F8 28" Valve 02BS-F6 28" Valve 02BS-F7 28" Valve 02BS-F14 28" Cast Elbow 02BD-F12 28" Pump 02BD-F9 28" Valve 02BD-F8 28" Valve 02A-S4 28" Cross 028-F6 28" Cross 02-F1 22" Valve 02A-F1 22" Valve 02A-S3 22" Cross

.02A-F5 22" Cross 02-F2 22" Valve 028-Fi "

22" Valve 02B-F5 22" Cross 028-S7 22" Cross 02F-F6 12" Reducer 02L-F6 12" Reducer 02BD-SS 4" Sweepolet 02AS-S10A 4" Sweepolet 10S-F1 RHR-SDC 20" Tee 10AD-F1 RHR-LPCI 16" Tee 10AD-F4 16" VaIve 103D-F1 16" Tee 10BD-F5 16" VaIve 14A-F6 Core Spray 10" Valve 12S-F28 RWCU 6" Valve 10HS-S1 Head Spray 4" Flange

1. 0408B/37

QUESTION 1:

Provide a list of welds where only one side access was available for ultrasonic examination?

Answer:

Table 1 summarizes the welds which had only one side ultrasonic access.

QUESTION 2:

What are the applied stress components and stress ratios for welds 02J-S4 and 02K-S37 Answer:

Weld # Dead Neight Thermal Seismic Pressure Ratio 02J-S4 118 161 216 6811 .43 02K-S3 225 624 339 6811 .44 All stresses are in units of psi.

For 304 stainless, sm = 16800 psi A sketch of the location of the individual circumferential indications for both 02J-S4 and 02K-S3 is attached.

QUESTION 3:

How are overlay lengths selected for repair of axial flaws?

Answer The overlay for axial flaws is designed to function as a leak barrier.- The minimum length assuming no geometric constraints is 0.75 inch beyond the edge of the weld crown. However, the overlay is sized to extend at least 1/2 inch beyond the end of the flaw. l This can lead to overlays which are asymmetric with respect to weld l

-centerline and in some cases which exceed the minimum length.

8928N

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7 3 QUESTION 4:

How many welds are inaccessible for UT inspection?

Answer:

Our March 1, 1984 submittal provided among other items, a summary of the inaccessible welds. That list was subject to change based on our inspection efforts this outage. Subsequently it was found that an additional weld on the Shutdown Cooling System was inaccessible. For the sake of completeness a summary of the number of inaccessible welds by system is provided below:

System Number of Inaccessible Welds LPCI (16") 2 Shutdown Cooling (20") 2 Head Spray (4") 1 Core Spray (10") 2 Reactor Water Cleanup (6") 3 Total - 10 8928 l

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