ML20199F248
| ML20199F248 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 06/19/1986 |
| From: | Zimmerman S CAROLINA POWER & LIGHT CO. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| References | |
| NLS-86-190, NUDOCS 8606240237 | |
| Download: ML20199F248 (11) | |
Text
_.
Cp&L Carolina Power & Light Company JUN 19 1986 Director of Nuclear Reactor Regulation Attention:
Mr. Dan Muller, Director BWR Project Directorate #2 Division of BWR Licensing United States Nuclear Regulatory Commission Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-324/ LICENSE NO. DPR-62 CORRECTION LETTER IGSCC INSPECTION RESULTS - BRUNSWICK-2 RELOAD 6
Dear Mr. Muller:
1 On May 8,1986, Carolina Power & Light Company submitted the results of the IGSCC inspections conducted during the Brunswick-2 Reload 6 outage. Page 4 of the cover letter for this submittal contained typographical errors. A corrected page 4 is included as Enclosure 1. Vertical bars in the right hand margin indicate where revisions have bee made.
In addition, NUTECH has provided revised pages to their design report included as of the May 8,1986 submittal. These pages, along with a summary list revisions, are included as Enclosure 2. Vertical bars in the right hand margin indicate where revisions have been made.
(919) 836-6901.Please refer any questions regarding this matter to Mr. Stephen D. Floyd i
Yours very truly, fr S. R. Zimme man Manager Nuclear Licensing Section SRZ/ MAT /pgp (3934 MAT)
Enclosure Mr. W. H. Ruland (NRC-BNP) cc:
Dr. 3. Nelson Grace (NRC-RII)
Mr. E. Sylvester (NRC)
NO bo!k
$4 G
ge\\
411 Fayetteydle Street e P. O. Box 1551
- Raleigh. N. C. 27602 I
ENCLOSURE 1 TO SERIAL: NLS-86-190 (3934 MAT /ccj)
Mr. Dan Muller NLS-86-158/Page 4 1
Mitigation / Repair No. of Weld Jo.ots IHSI
$8 Weld Overlay Repair 32 IHSI & Weld Overlay Repair 7
Solution Anneal 8
Unmitigated
_2 Total 107 Table 1 provides a detailed breakdown of the mitigations and repairs performed on each susceptible weld joint.
Compensatory Actions The following special surveillance measures have been implemented at the Brunswick Plant:
1)
As required by the Technical Specifications, plant shutdown shall be initiated for inspection and corrective action shall be taken when any leakage detection system indicates, within any period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, an increase in the rate of unidentified leakage in excess of 2 gpm. For sump level monitoring systems with fixed-measurement interval method, the level shall be monitored at 4-hour intervals or less.
2)
At least one of the leakage measurement instruments associated with each sump shall be operable and the outage time for inoperable instruments shall be limited to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Otherwise, an orderly shutdown will be immediately initiated.
3)
A visual examination for leakage of the reactor coolant piping shall be performed during each plant outage in which the containment is deinerted provided that such an inspection has not been made in the previous 92 days. The examination shall be performed consistent with the requirements of IWA-5241 and IWA-5242 of the 1980 Edition of Section XI of the ASME Boiler and Pressure Vessel Code. The system boundary subject to this examination shall contain the susceptible welds inside the primary containment.
These special surveillance measures are consistent with those given in Attachment I to Generic Letter,84-11 and CP&L's ALARA Program.
Conclusion CP&L has completed IHSI on 65 susceptible weld joints and has replaced the 6-inch, Class 1, Reactor Water Cleanup System piping with nuclear grade materials. Of a susceptible weld population of 107 welds,105 of these welds have been mitigated by either IHSI, weld overlay repair, or solution annealing. The two unmitigated weld joints are the 4-inch decontamination ports attached to the 28-inch suction piping.
UT examinations were performed on 100 percent of the susceptible stainless steel weld population using the fully automated GE SMART UT System where geometrically feasible.
Full structural overlays were applied to piping weld joints less than 28 inches in diameter with indications. Five existing weld overlays were upgraded to full structural requirements. Leak barrier overlays were applied to the seven 28-inch pipe weld joints with indications. The piping weld joints with indications have been repaired by weld overlay.
ENCLOSURE 2 TO SERIAL:
l (3934 MAT /ccj)
SUMMARY
LIST OF REVISIONS PAGE NO.
DESCRIPTION OF CHANGE 6
Specified that ultrasonic examinations were performed on completed weld overlays.
13 Indicated that some welds of the Brunswick-2 recirculation system had been solution annealed rather than treated by IHSI.
18 Corrected Reference 7 to indicate use of NUTECH Computer Program PISTAR, Level 3.3.1.
A.1 Revised the configuration of weld 2B32-RR-12-AR-Cl to RED-P.
A.3 Included a definition of RED in Note 1.
E.3 Revised the title of Table E.3. Also, changed the shrinkage stress associated with l
weld 28-A5 from 502 psi to 519 psi.
(3934 MAT /ccj )
l h
l j
f is Type 308L which is resistant to IGSCC propagation because of its duplex (austenite-ferritel structure.
i Nondestructive examinations of each weld overlay 1
consisted of:
l 1.
Surface examination of the first weld overlay layer by the liquid penetrant examination technique in 1
)
accordance with USNRC Generic Letter 84-11 i
l (Reference 2).
2.
Delta ferrite content measurement of the first layer using a Severn gauge.
s 3.
Surface examination of the completed weld overlay by the liquid penetrant examination technique, in accordance with ASME Section XI (Reference 1).
4.
Ultrasonic examination of the completed weld l
~
overlay and existing circumferential pipe weld in accordance with ASME Section XI (Reference 1).
I I
I XCP-34-101
'6 Revision l r
q t
E l
5.0 WELD OVERLAY REPAIR SHRINKAGE STRESSES I
f A certain amount of axial shrinkage is associated with each weld overlay repair.
Appendix E contains a listing i
of the shrinkage at each weld overlay location.
These E
l shrinkages induce stresses throughout the recirculation system.
NUTECH's computer program PISTAR (Reference 7) l was used to determine the magnitude of these stresses.
Figure 5.1 presents the PISTAR mathematical model used.
The calculated stresses are listed in Appendix E at un-flawed locations.
I E
Weld overlay shrinkage stresses were evaluated to assure
)
they do not contribute to crack growth in unflawed pipe.
P 1
Since all unflawed pipe welds (except for the twelve (12) Inconel safe-end to nozzle welds at the reactor pressure vessel and the two (2) 4" decon connections on the 28" suction lines) in the Brunswick Unit 2 recircu-lation system have been treated by the Induction Heating Stress Improvement (IHSI) process or have been solution annealed, the favorable residual stresses imposed by these processes would have to be overcome to induce IGSCC. Further analyses demonstrated tihat the highest combination of deadweight, internal pressure, thermal, E
and weld ovdrlay shrinkage stresses present at any weld XCP-34-101 13 Revision 1 g
nutasb
i 7.
NUTECH Computer Program PISTAR, Level 3.3.1, File i
- _f Number QASJO. SOFT.036.3.30.2.,
8.
NUTECH Computer Program NUTCRAK, Version 2.0.2, l[
[
File Number QASJO. SOFT.049.2.0.0.2.
9.
"BSEP Unit 2 IGSCC Indication List," all revisions oi through 13, File Number CPLO34.0012.
10.
" Weld Overlay As-Built Dimensions," CPL File Number PM-85-030, Rev. O, File Number CPLO34.0012.
v er I
11.
U.S. Nuclear Regulatory Commission Document No.
NUREG-1061, Volume 1, " Investigation and Evaluation of Stress-Corrosion Cracking in Piping of Boiling j
4 Water Reactor Plants," April 1984, Second Draft attached to SECY-84-301, dated July 30, 1984.
12.
EPRI Document No. NP-2662-LD, " Computational Residual Stress Analysis for Induction Heating of f
Welded BWR Pipes," December 1982.
1 I
i
=!I;!
.i
,ji XCP-34-101 18 Revision 0 nutggb c
1 Pipe Pipe Wall III l
Weld ID-Size Rickness Configuration Flaw DescriptionI4)
E 2B32-RR-4A-1 4"
0.36" P-WOL E rough-wall defect, weld-o-let side 2B32-RR-4A-11 4"
0.36" P-WOL E rough-wall defect, weld-o-let side 1
E 2B32-RR-4B-1 4"
0.36" P-WOL E rcugh-wall defect, weld-o-let side 1
0.36" P-WOL (2) 2B32-RR-12-AR-A2 12" 0.70" P-E Axial, 0.20" length, J
pipe side 2B32-RR-12-AR-A3 12" 0.80" E-P 5 axials, 0.25" max.
I length, elixu side 2B32-RR-12-AR-B2 12" 0.70" P-E 0.60" x 20% circ.(3),
l pipe side E
2B32-RR-12-AR-B3 12" 0.68" E-P 1.00" x 20% circ.(3) 1 elbow side l
2B32-RR-12-AR-Cl 12" 0.68" RED-P 3.0" x 100% circ.,
l 3 axials, 0.30" max.
length, all pipe side E
2B32-RR-12-AR-C2 12" 0.76" P-E 3 axials, 0.60" max.
l length, elbow side 2B32-RR-12-AR-C3 12" 0.78" E-P 3 axials, 0.40" max.
length, elbow side 2B32-RR-12-AR-C4 12" 0.70" P-PP 7.4" x 38% cire.(3),
pipe side 2B32-RR-12-AR-D1 12" 0.62" SWP-P 3.0" x 25% circ.(3) pipe side 2B32-RR-12-AR-D4 12" 0.62" P-PP Axial, 0.20" length, pup piece side;
' axial, 0.35" length, pipe side 2B32-RR-12-AR-E2 12'"
~
0.80" P-E 7 axials, 0.60' max.
length, elbow side 2B32-RR-12-AR-E3 12" 0.76" E-P Axial, 0.35" length, elbow side XCP-34-101 A.1 Revision 1 nutggb
j l
I Pipe Pipe Wall l
Weld ID Size Thickness Configuration (1)
Flaw Description (4)
I 2B32-RR-28-A8 28" 1.30" E-V 2 axials, 0.75" max.
l length, elbow side 2B32-RR-28-A13 28" 1.50" P-V
'1.2" x 10% circ. (3),
pipe side j
2B32-RR-28-B3 28" 1.17" P-E 4 cires.(3), 21% x 8.0" (max. depth x
)
total length); axial, 0.40" length; all E
elbow side 2B32-RR-28-B4 28" 1.20" E-P 6 cires.I3), 24% x 6.9" (max. depth x l
total length), axial, 0.30" length, all elbcw side
}
2B32-RR-28-B5 28" 1.19" P-P 4 cires.(3), 27% x 6.25" (max. depth x total length), up-l stream side l
2B32-RR-28-Bll 28" 1.27" E-P 1.2" x 18% circ. (3) y p
elbow side 1
l Notes:
I
- 1) P = Pipe, lOL = Weldolet, E = Elbow, RED = Beducer, PP = Pup Piece, SWP = Sweepolet, EC = End Cap, V = Valve, Cr = Cross, P = Punp.
p
- 2) No flaw detected but weld overlay repaired as a pre-cautionary neasure.
- 3) Circumferential1y oriented flaw with associated axial cmponent.
- 4) Reference 9.
g i
i l
l l
XCP-34-101 A.3 Revision 1 g
nutggh
p Table E.2
-UNFLAWED IHSI TREATED 12",
22", AND 28" PIPE RECIRCULATION SYSTEM WELDS -WELD OVERLAY SHRINKAGE STRESS i
1 Weld ID Stress (psi) j 12-AR-Al 2199 l
12-AR-A4 4217 12-AR-B 1 2416 E
12-AR-B4 7925 12-AR-D2 5031 12-AR-D3 4356 12-A4-El 7103 28-A3 452 28-A5 519 l
E 28-A6 631 J
28-A7 337 l
28-A9 34 l
28-A10 43 l
E 28-All 54 28-A12 117 28-A14 27 2
.E 28-A15 346 28-A16 297 28-A17 1259 22-AM2 2031 E
g 22-AM3 1284 22-AM4 1238 2 2-A!!6 0
22-AM1 2691 12-BR-Fl 5442 12-BR-H1 2617 12-BR-H3 1699 12-BR-J1 3046 12-BR-J 4 3568 12-BR-K1 2633 12-BR-K4 1097 28-B6 341 28-B7 302 28-B8 224 28-B9 149 28-B10 127 28-B12 99 28-B13 83 28-B14 108 l
28-B15 157 28-B16 1089 136 28-B17 2 2-BM2 1629 22-BM3 1802 2 2-BM4 3174 XCP-34-101 E.3 Revision 1 g
_. ___