ML20207B543
| ML20207B543 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 07/15/1986 |
| From: | Wojnarowski J COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 1851K, GL-84-11, NUDOCS 8607180101 | |
| Download: ML20207B543 (5) | |
Text
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,-mN CommonweaMh Edison 72 West Adams Street, Chic go,lilintia Z_
] Address Fleply to: Post Offica Box 767
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'V Chicago, tilinois 60690-0767
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July 15, 1986 Mr. N'rold R. Denton, Director Office of Nuclear Reactor Regulation U.S. tAlclear Regulatory Commission Washington, DC 20555
Subject:
Quad cities Station Unit 2 Stainless, Steel Piping Inspection Plan, Fall 1986 Refueling Outage NRC Docket No. 50-265 Reference (a): Letter from J. A. Zwolinski to D. L.
Farrar dated January 7, 1986.
Dear Mr. Denton:
In accordance with the referenced letter, this transmittal provides our piping inspection plan for the Quad Cities Unit 2, Fall 1986 Refueling Outage. The inspection plan was prepared consistent with the guidance in Generic Letter 84-11.
Attachment A provides a general description of the inspection plan including inspector qualifications and provisions for crack evaluation and l
sample expansion. Also included is a table detailing the number of welds by system and pipe size to be examined.
Commonwealth Edison is aware that the NRC intends to issue NUREG-0313 Revision 2 for comment at some point in the future. However, since these new requirements have not yet been issued; we have established our inspection plan in accordance with the existing regulatory requirements and submitted it for your review on the schedule required in the referenced letter. To avoid any impact on our refueling outage schedule, we request your concurrence with the attached inspection plan by September 1, 1986.
The Unit 2 outage is currently scheduled to-begin October 15, 1986.
If you have any questions regarding this transimittal, please contact I
this office.
I 8607180101 860715 W
PDR ADOCK 05000265 l
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G PDR l
Mr. H. R. Denton July 15, 1986 One signed original and forty (40) copies of this letter and the attachment are provided for your use.
Very truly yours, I
I g
J. R. Wojn rowski Nuclear Licensing Administrator 1m Attachment cc: Resident Inspector - Quad Cities R. Bevan - NRR 1851K
ANA QUAD CITIES UNIT 2 FALL 1986 OUTAGE PIPING INSPECTION PLAN 1.
During the fall 1983 outage, Induction Heat Stress Improvement (IHSI) was performed on approximately 100 welds (77 recirculation welds, 10 RHR.
welds and 13 RWC welds). There are currently no plans to perform IMSI on any welds during this outage.
l l
2.
The accompanying table titled, " Quad Cities Unit #2 84-11 Augmented Inspection Plan", provides the sampling plan for addressing the Intergranular Stress Corrosion Cracking (IGSCC) concerns during the Quad Cities Unit 2 Fall-1936 outage. The augmented inspection will consist of 64 weld examinations.
It should be noted that Quad cities Unit 2 has Previously been 100% inspected.
1 3.
With respect to weld overlay inspections, the NRC Safety Evaluation Report (SER) for the Unit 2 Spring 1985 inspection program noted that our weld overlay designs took credit for uncracked piping ligaments.
I The SER indicated that UT inspection of overlays should be perfcraed.
during the next refuel outage and that these inspections should detect and size the existing cracks. In response to the SER concerns, our
- i proposed inspection plan includes UT inspection of all existing weld overlays using the EPRI overlay inspection techniques. Prior to inspection, designed overlays will be increased to full structural overlays. All overlays will be surface finished as necessary to facilitate the inspection. Since the overlays will no longer take credit for uncracked piping ligaments, our inspection will cover the overlay material and the upper quarter thickness of the original pipe rather than attempting to detect and size previously identified cracks.
This approach is consistent with the current EPRI overlay inspection techniques.
Currently, there are fourteen weld overlays installed at Quad Cities Unit 2.
Eleven of the weld overlays cover welds that have indications greater than 10% of circumference.
In accordance with GL 84-11, these overlays will be inspected using EPRI techiques.
The remaining three overlays cover welds with indications less than 10%
of circumference. Two of the three overlays are designed overlays and the remaining overlay is full structural. In response to the above mentioned SER concern and to support continued operation with these overlays, they also will be inspected.
.' 4.
Ten welds with indications mitigated by induction heat stress improvement are included in this inspection plan.
5.
Recirculation inlets safe end welds on the Quad 2 recirculation system are considered a separate category from piping welds. These safe ends are low carbon type 304SS and the nozzle to safe end welds have corrosion resistant cladding on the inside diameter which cover the welds and adjacent heat affected zones. The reason for the inspection of two twelve inch safe ends is the concern for IGSCC of the thermal sleeve attachment weld.
6.
All stainless steel weld examinations will be performed by special Level II inspectors, qualified by EPRI after September 10, 1985. Examinations on weld overlays will be performed by a special Level II inspector qualified by EPRI to inspect weld overlays.
7.
Each flaw indication will be evaluated in accordance with the guidance of NUREG-1061 Volume 1 and GL 84-11.
If repairs are required, weld overlays will be utilized which take into account flaw characterization, depth, length, and material toughness concerns for SMAW and SAW deposited material. All welds with an axial crack will have an overlay repair applied.
If there is a flaw indication that is less than or equal to 10% of circumference and less than or equal to 30% in depth and IHSI has been applied, the crack growth analysis will include the beneficial residual stress pattern from IHSI.
8.
If cracks are found within the inspected sample of a specific piping category, another equivalent sample of the same number in that category will be inspected. Categories are defined by the horizontal lines on the accompanying table.
For example, the first category is Recircula-tion which would include Risers, Header and outlets.
The next category would include LPCI, SDC, and CS.
As noted in Item 5, the recirculation inlet safe end welds are treated as a separate category.
1851K l
l
Quad cities Unit #2 84-11 Augmented Inspection Plan 1
2 3
4 5
6 7
8 9
10 1986 1985 1983 1986 WELD IllSI 84-11 84-11 83-02 84-11 WELD OVERLAY MITIGATED TOTAL SYSTEM SIZE TOTAL EXAMS EXAMS SAMPLE OVERLAYS SAMPLE CRACKS SAMPLE 1
Recirculation l l
l l
l l
l l
l l
l Risers l
12" l 44 l
13 l
22 l
7 l
7 l
T l
2 l
16 ' l I
SE (Thermal l 12" l 10 l
1 l
9 l
2 l
0 l
0 l
0 l
2 l
Sleeve) l l
l l
l l
l l
l l
Ileader l
22" l 22 l
4 l
16
}
4 l
0 l
0 l
2 l
6 l
Outlets i
28" l 30 l
2 l
17 l
4 l
5 1
5 l
6 l
15 l
1.PCI l
16" l <32a l 6
l 23 l
6 l
0 l
0 l
0<
l 6
l SDC l
20" l 18a l 3
l 11 l
3 l
2 l
2 l
0 l
5 l
CS 1
10" 1 27a 1 5
l 20 1
5 l
0 1
0 1
0 1
5 l
IIS/RWCil l
6" l 13a l 6
l 4
l 3
1 0
1 0
l l
3 l
Recirc/CRD l
l l
l l
l l
l l
l IIS/Irv j
4" l 34al 10 l
23 l
7 l
0 1
0 l
0 l
7 l
JPI l
l 10 l
10 1
0 1
2 l
0 1
0 l
0 l
2 l
240 43 14 10 67 COI.tlMN e
3-TOTAL STAINLESS STEEL WEl.DS SUSCEPTIBLE TO IGSCC ON A PARTICULAR SYSTEM OR SIZE.
4-TOTAL WELDS EXAMINED UNDER GENERIC LETTER 84-11 CRITERIA.
EXAMINERS WERE QUALIFIED TO Tile 83-02 REQUALIFICATION.
S-TOTAL WELDS EXAMINED UNDER Tile 83-02 REQUALIFICATION.
6-GENERIC LETTER 1986/84-11 SAMPLE.
7-TOTAL WELD OVERLAYS ON A PARTICULAR SYSTEM AND SIZE.
8-GENERIC LETTER 84-11 WELD OVERLAY SAMPLE. OVERLAID WELDS WITil CRACKS GREATER TilAN 10%
OF TilEIR CIRCUMFERANCE WILL BE INSPECTED.
9-TOTAL CRACKED WELDS WITil IllSI AS A MITIGATOR.
10 - GENERIC LETTER 84-11 1986 TOTAL SAMPLE.
NOTE: a 16" WELDS ON LPCI, 2-20" WELDS ON SDC, 2-10" WELDS ON CORE SPRAY, 3-6" WEl,DS ON REACTOR WATER CLEAN UP AND l-4" WELD ON llEAD SPRAY ARE INACCESSIBLE TO UT.
3211B/34
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