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7U.S.NRCUnited Srates Nuclear RcgulJ,rory Commission

Protecti1lg People tI1la tbe Environmellt June 2011 Meeting

• Meeting held in Rockville, MD June 6-7, 2011- Alloy 690 Research- Weld metal development- Chemical mitigation

• 30 Representatives from NRC, Industry,National Laboratories, and Universities- EPRI, GE, Westinghouse, DEI, SIA, Special

Metals WPC, BMPC-KAPL, PNNL, INL, ANL, NEI

11/30/2011 Alloy 690 Expert Panel Meeting 2

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.,-~(U.S.NRCUnited States Nuclear Rcgula[Qry Commission

Protecting People and tbe Environment June 2011 Meeting Highlights

• Review of prioritized knowledge gaps• Crack growth rate data and identified tests for

Alloy 690 and weld metals• Weld metal development• Results of EPRI sponsored CGR tests• Results of NRC sponsored CGR tests• Materials characterization• Chemical mitigation• xLPR development update

11/30/2011 Alloy 690 Expert Panel Meeting 3

'7U.S.NRCUnited States Nuclear Rcgub.£Ory Commission

Protecting People a,ui tbe Environment Action Items (1/3)1. Review and discuss the residual plastic strain profile and dilution

zone characteristics of dissimilar metal welds prior to testing.

Status: Still needed; NRC sponsored testing of DMW dilution zonespecimens is currently underway.

2. Additional discussion of the ANL weld overlay test results todetermine the effect of loading on the crack paths and developrefined approaches for evaluating weld overlays.

Status: Additional testing conducted and future test are planned.Recently acquired data will be discussed at this meeting.

3. Review test results and test conditions for the alloy 152 weld that iscurrently being tested at ANL, PNNL, and GE.

Status: PNNL and ANL initial testing with new ANL weld specimen arecompleted. Data will be reviewed at this meeting.

11/30/2011 Alloy 690 Expert Panel Meeting 4

-:JU.S.NRCUnited States Nudear Regulatory Commission

Protecting People and the Environme1lt Action Items (2/3)4. Additional discussion of phase stability modeling particularly for the

development of weld metal compositions and evaluation of thephase stability of dissimilar metal welds.

Status: No discussions to date. Effort should be coordinatedwith DMW dilution zone characterization and testing.

5. Obtain input from industry and NRC staff currently developingxLPR Version 2 on data needs.

Status: Reactor coolant system information for 2 examplePWRs is being collected. Information, including materials andweld joint geometries, should be available in January 2012.The information collected will be used for several purposesincluding residual stress profiles and identifying additionalPWSCC data needs.

11/30/2011 Alloy 690 Expert Panel Meeting 5

~,~U.S.NRCUnited States Nuclear Rcgula[Ory Commission

Protecting People and tbe Environmellt Action Items (3/3)

6. Reactivate the crack initiation working group and obtain an updateon the data application working group activities at the EPRIsponsored meeting in December 2011..

Status: Planned joint working group discussion at this meeting.

7. Determine interest in crack initiation or crack growth rate testing ofavailable alloy 690 materials removed from service.

Status: NRC has interest in obtaining materials for crackgrowth rate testing. CRDM nozzle J-groove weld with alloy 52weld overlay has been harvested. Material has not beendecontaminated.

11/30/2011 Alloy 690 Expert Panel Meeting 6

't7U.S.NRCUnited States Nuclear RcgulJ,tory Commission

Protecting People and tbe Environmellt . NRC Sponsored Research1. Alloy 152/52 crack growth rates

- Weld overlays and inlays with 152 and 52M- 152 weld material- Shielded Metal Arc Weld (SMAW) and Gas Tungsten Arc Weld (GTAW)

parameters- Ductility dip cracks and solidification cracks

2. Dissimilar metal welds dilution zones- 152/stainless steel- 152/low alloy steel- 52M/stainless steel- 52/low alloy steel

3. Weld HAZ in Alloy 690- 152/690- 52/690- 52MSS/690

11/30/2011 Alloy 690 Expert Panel Meeting 7

7U.S.NRCUnited Slates Nuclear Rcgula£Ory Commission

Protecting People ana the Environme1lt NRC Sponsored Research

4. Thermo-mechanical processing effects- Systematic thermo-mechanical processing to isolate the effects ofmicrostructural changes on PWSCC susceptibility

Compare results obtained to data from mockups and specimensharvested from retired components

High levels of cold work (>20 percent) does not appear to be a validsimulation of fabrication processes or weld heat affected zones

• Modeling of component fabrication

• Vendor fabrication requirements

• Characterization of weld heat affected zones

11/30/2011 Alloy 690 Expert Panel Meeting 8