ML20234C156
| ML20234C156 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 06/24/1987 |
| From: | Allen C COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 3247K, GL-84-11, NUDOCS 8707060357 | |
| Download: ML20234C156 (3) | |
Text
l
.Comm:nwealth Edison
- i. One First National Plaza. Chicago, Illinois (V
. Address Reply to: Post Office Box 767 Chicago, Illinois 60690 - 0767 June 24, 1987 l
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
Subject:
LaSalle County Station Unit 2
{
Stainless Steel Piping Inspection I
plan, Fall 1986 Refueling Outage' i
NRC Docket No. 50-374 References (a):. Letter from J.A. Zwolinski to D.L. Farrar dated January 7, 1986.
(b): Letter from C.M. Allen.to H.R. Denton dated September 14, 1986.
(c): Letter from Dr. A. Bournia to D.L. Farrar dated December 16, 1986.
(d): Letter from C.M. Allen to H.R. Denton dated January 14, 1987.
(e): Letter from Dr. A. Bournia to D.L. Farrar dated March 5, 1987.
Dear Mr. Denton:
In accordance with Reference (a), we provided our piping inspection plan for the LaSalle County Station Unit 2 Refueling Outage in Reference (b).
The inspection plan was prepared consistent with the guidance-in Generic Letter 84-11.
Reference (c) transmitted Nuclear Regulatory Commission acceptance of that inspection plan. Reference (d) transmitted clarification to the acceptance and Reference (e) indicted acceptance of the plan as clarified.
Augmented Inspections of IGSCC susceptible piping was conducted during the LaSalle Unit 2 Fall 1986 refueling outage. The inspection followed the plan submitted to the NRC and subsequently approved by the NRC.
The inspections were performed by General Electric Special Level II ultrasonic (UT) examiners. Data packages were reviewed by CECO UT Personnel and final acceptance or evaluations of indications were made by CECO Level III personnel.
K f
lL )I pf PDR
i U.S. NRC June 24, 1987 The UT data of the welds examined showed no detectable IGSCC flaws.
Mechanical stress improvement was performed on 54 welds this outage, 15 of which were carbon steel safe ends welded to carbon steel nozzles with Inconel 182 buttering. The balance of 39 was performed on stainless piping or safe ends welded with Inconel 182 material.
Inco 182 is a material which is susceptible to IGSCC; therefore CECO decided to stress improve safe ends / nozzle welds having Inconel 182 buttering. The data is shown on Table 1 (attached).
j The Inconel 182 buttering / weld material was inspected by a CECO developed procedure based on EPRI Guidelines and proven to be effective on a mockup. This provided confidence in the UT examinations. No indications of IGSCC were detected in the buttering.
If you have any questions regarding this matter, please contact this office.
Very truly your C. M. Allen Nuclear Licensing Administrator 1m Attachments cc: Region III Inspector - LSCS Paul Shemanski - NRR Region III Office - RIII l
1 3247K I
ATTACHMENT TA,BLE 1 LaSalle Unit 2 Fall 1986 GL 84-11 Inspection of Stainless Steel Piping No. of Welds 84-11(A)
Stress Improved Total No. of System Size Total 1987 Welds Inspected Recire.
24" 42 4
8 16" 8
0 4
12" 30 10 10 RHR 20" 11 8
8 12" 13 7
8 I
Recirc.
RHR 4"
25 10 10 JPI 129 39(B) 48 A - Total number of stainless steel welds that fall under generic letter 84-11 requirements B - An additional 15 welds of carbon steel material joined with Inconel 182 were also stress improved.
3247K