ML17199T440
| ML17199T440 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 10/15/1987 |
| From: | Silady J COMMONWEALTH EDISON CO. |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| 3712K, GL-84-11, NUDOCS 8711250065 | |
| Download: ML17199T440 (3) | |
Text
Common.Ith Edison One First Na. I Plaza, Chicago, Illinois Address Reply to: Post Office Box 767 Chicago, Illinois 60690 - 0767 Mr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory commission Washington, DC 20555 October 15, 1987
Subject:
Dresden Station Unit 3 Submittal of IGSCC Inspection Plan for the 1988 *Outage
~c Docket No. 50-249 __ _
References:
{a)
Generic Letter 84-11 dated April 19, 1984 concerning Inspections of BWR Stainless Steel Piping
{b)
B. Rybak letter to H. R. Denton lett_er dated June 3, 1985
{c) J. R. Wojnarowski letter to H. R. Denton dated July 18, 1986
Dear Mr. Murley:
The Reference {a) letter required ongoing IGSCC inspections to be conducted during BWR refueling outages.
Reference {b) provided the Commonwealth Edison.plan *to replace the reactor recirculation system and portions of ottie'r IGSCC susceptible piping for Dresd~n, Unit 3 duripg its Fall 1985 outage.
Ariy susceptible piping not repl~ced.: was. inspected in accordance with Generic Letter 54.:...11 and *results were*provid~d.in Referenc;e. {c,).
This transmittal provides the IGSCC inspection plan for the Winter 1988 -Dresden 3 outage in accordance with Generic Letter 84-11..,To facilitate final outage planning, your concurrence is requested by December 15, 1987, i.e. approximately one month prior to the currently scheduled shutdown date.
Please contact this office should further information be required.
Very truly yours, RC:~
Nuclear Licensing Administrator Attachment cc:
M. Grotenhuis - NRR NRC Resident Inspector - Dresden 3712K/bs
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Dresden Unit 3 Plan for IGSCC Related Activities Winter 1988 Outage During the Fall 1985/Spring 1986 Recirculation Pipe Replacement outage most of the IGSCC susceptible piping was replaced using IGSCC resistant Type 316 NG material.
This replacement piping will be inspected under the normal Section XI Inspection Program.
However, there is some remaining Class 1 stainless steel piping that is subject to Generic Letter 84-11 requirements.
There are a total of fifty (50) welds in this category of which 28 were stress improved.
The following paragraphs summarize the planned IGSCC related activities.
- 1.
The accompanying table titled Augmented Stainless Steel Weld Inspection Plan - Winter 1988 - Dresden Unit Three provides the sampling plan for addressing intergranular stress corrosion cracking concerns.
The plan follows the requirements of Generic Letter 84-11.
- 2.
The proposed inspection plan includes UT inspection of twelve (12) previously examined ~alds, ~ince all of the 47 accessible IGSCC susceptible welds were ult1rasonically examined at least once during the Dresden 3 refueli~g outages in 1983 and 1985.
- 3.
All stainless steel weld examinations will be performed by level II or III inspectors qualified by EPRI after September 10, 1985.
Automated UT techniques may be employed.
Results of the contractor examinations will be provided to CECo.
CECo NOE personnel will be utilized for review of data sheets and final resolution of flaw indications.
These CECo personnel were also qualified at the EPRI NDE Center after September 10, 1985.
- 4.
If any additional IGSCC flaw indication is identified, it will be resolved consistent with the intent of Generic Letter 84-11.
If repairs are required, weld overlays may be utilized which will take into account flaw characterization, depth, length, and material toughness concerns fer SMAW and SAW deposited material.
- 5.
If flaws are found within the first inspection sample of a specific piping category, anot~er equivalent sample of the same number in that category will be inspected.
0037S-2 If flaws are found within the second inspection sample of a specific piping category, the remaining accessible welds in that category will be inspected.
Categories are defined by the horizontal lines on the attached table.
Augmented Stainless Steel Weld Inspection Plan Winter* 1988 Dresden Unit Three Not. Prev.
Prev.
Exam (2) 1988 Category Size Total Exam (1)
(Inaccessible)
Prev.
Isolation Condenser 14" 14(3) 13 Core.Spray 10" 29 27 Reactor Head.Vent 4"
3 3
Spare Nozzle 6"
2 2
Head Spray 6"
2 2
50 47
~eld with known flaws Prnviously examined weld -
198~ sample 1'Jol: pr~:viously examined tiJeld - 1988 sample Weld overlay sample Total 1988 Sample 1
2 0
0 0
0 12 0
0 3
12 Inspections 3
5 2
1 1
12 84-11 SamQle Not Exam Prev. Exam 0
0 0
0 0
0 i\\IOT!~ : ( 1. )
(2)
Welds that were ultrasonically examined previously to addres~ IGSCC concerns.
Welds that were not ultrasonically examined previously to address IGSCC concerns.
(3)