ML093170166

Part 1 of 4--Weld Overlay Examination Report 2R19

ML093170166
Person / Time
Site:	Millstone
Issue date:	11/12/2009
From:	Dominion Nuclear Connecticut
To:	Office of Nuclear Reactor Regulation
Sandeers, Carleen, NRR/DORL, 415-1603
Shared Package
ml093170104	List: ML093160744 ML093170166 ML093170173 ML093170176
References
FOIA/PA-2011-0115
Download: ML093170166 (80)

Text

2R19 WELD OVERLAY (WOL) EXAMINATION REPORT Dominion Nuclear Connecticut, Inc. (DNC) hereby provides the Examination Report for Ultrasonic Testing (UT) examinations of structural WOLs performed during refueling outage 2R19. Final examinations were completed on November 1, 2009.

A final stress analysis that documents weld overlay qualification including residual stresses, transient stresses, and flaw growth evaluation has been previously submitted to the NRC as attachment 3 to DNC letter dated July 23, 2009 (ADAMS Accession No. ML092090215).

Additionally, DNC has measured shrinkage of the piping as a result of the overlay application.

The preliminary evaluation of shrinkage stresses arising from the weld overlays shows that the resulting stresses are within acceptable ASME code limits and have no significant impact on the associated piping or supports. Completion of these evaluations is tracked by the corrective action program (CA150207 and CA150954). Affected supports and restraints have been checked and remain satisfactory after overlay application. Analyses for the reactor coolant

system (RCS) branch piping that evaluate the impacts of weld shrinkage and stiffness are contained in separate changes to individual piping stress calculations. The impacts from shrinkage and stiffness are acceptable and the individual piping stress calculations will remain available on site for review.

Information included in the balance of this report is provided as follows.

a. WOL examination results that includes a listing of indications detected and coverage limitations.

b. The disposition of indications using the standards of ASME Section XI, IWB-3514-2 and/or IWB-3514-3 criteria.

c A discussion of any needed repairs to the WOL material and/or base metal and the reasons for the repairs.

For items a and b, there were no 2R19 structural WOL indications noted in the submitted inspection reports. Any limitations to the inspections are noted in the following individual inspection reports.

Dissimilar Metal Adjacent Welds (DMWs) SS Weld Location Page BSI-C-1001 BSI-C-1003 12-inch Cold Leg Safety Injection (SI) Loop 1A 3 BSI-C-3000 BSI-C-3002 12-inch Cold Leg SI Loop 1B 42 BSI-C-4000 BSI-C-4002 12-inch Cold Leg SI Loop 2B 81 BCH-C-2001 BCH-C-2003 2-inch Cold Leg Charging Loop 2A 120 BPY-C-1001 BPY-C-1003 3-inch Cold Leg Spray Line Loop 1A 150 BPY-C-3000 BPY-C-3002 3-inch Cold Leg Spray Line Loop 1B 180 BPD-C-1017 BPD-C-1019 2-inch Cold Leg Drain Line Loop 1A 210 BPD-C-2001 BPD-C-2003 2-inch Cold Leg Drain Line Loop 2A 240 BPD-C-3000 BPD-C-3002 2-inch Cold Leg Drain Line Loop 1B 270

For item c, the following 2R19 structural WOL repairs were performed.

a. BSI-C-4000 (Loop 2B Safety Injection Nozzle) - Liquid penetrant testing (LPT) of the sacrificial layer was unacceptable due to hot cracking. The area was repaired and LPT was re-performed with acceptable results.

b. BCH-C-2001 (Loop 2A Charging Nozzle) - LPT of the sacrificial layer was unacceptable due to hot cracking. The area was repaired and LPT was re-performed with acceptable results.

c. BPY-C-1001 (Loop 1A Spray Nozzle) - LPT of the sacrificial layer was unacceptable due to hot cracking. The area was repaired and LPT re-performed with acceptable results. d. BPD-C-1017 (Loop 1A Drain Nozzle) - While welding the 4 th bead of the 309L sacrificial layer the welder observed an expulsion of molten metal from the puddle and stopped the welding process. The area was LP examined and excavated, 3/4" long x 3/8" wide x 1/16" deep until the indication was reduced to an acceptable size meeting the base material acceptance criteria of ASME III.

The areas adjacent to the excavation were measured by UT to determine the actual wall thickness immediately above and below the indication. A contour gauge was used to show the profile indicating that the remaining wall thickness at the indication was 0.326".

This is 0.025" above the 0.301" min. pipe wall thickness.

The excavation was then welded and blended flush with the adjacent base material, and was LPT examined to the Pre-overlay standards with acceptable results.

e. BPD-C-1017 (Loop 1A Drain Nozzle) - LPT of the sacrificial layer was unacceptable due to hot cracking. The area was repaired and LPT was re-performed with acceptable results. f. BPD-C-3000 (Loop 1B Drain Nozzle) - LPT of the sacrificial layer was unacceptable due to hot cracking. The area was repaired and LPT was re-performed with acceptable results.

BSI-C-1001 / BSI-C-1003 12-inch Cold Leg Safety Injection (SI) Loop 1A

BSI-C-3000 / BSI-C-3002 12-inch Cold Leg SI Loop 1B