ML033370953

Additional Information Concerning a Proposed Alternative with the Use of Weld Overlay

ML033370953
Person / Time
Site:	Three Mile Island
Issue date:	11/20/2003
From:	Gallagher M AmerGen Energy Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
5928-03-20234
Download: ML033370953 (22)

Text

AmerGensM AmerGen Energy Company, LLC www.exeloncorp.com An Exelon/British Energy Company 200 Exelon Way Kennett Square. PA 19348 10 CFR 50.55a November 20, 2003 5928-03-20234 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Three Mile Island, Unit 1 Operating License No. DPR-50 NRC Docket No. 50-289

Subject:

Additional Information Concerning a Proposed Alternative Associated with the Use of a Weld Overlay

References:

1) Letter from Michael P. Gallagher (AmerGen Energy Company, LLC), to U. S.

Nuclear Regulatory Commission, dated November 3, 2003

2) Letter from Michael P. Gallagher (AmerGen Energy Company, LLC), to U. S.

Nuclear Regulatory Commission, dated November 7, 2003

3) Letter from Michael P. Gallagher (AmerGen Energy Company, LLC), to U. S.

Nuclear Regulatory Commission, dated November 18, 2003

Dear Sir or Madam:

In the Refererced letters, AmerGen Energy Company (AmerGen) requested a propost d alternative in accordance with 10 CFR 50.55a, "Codes and standards," paragraph (a)(3)(i) and supplied additional information requested by the U. S. Nuclear Regulatory Commission. This proposed alternative would permit the use of a full structural weld overlay repair for an indication identified in the steam generator "A" hot leg surge line nozzle-to-safe end weld. In response to a conference call between AmerGen and the U. S. Nuclear Regulatory Commission staff on November 13, 2003, Attachment 1 contains responses to several questions discussed during the cal!. Also attached is a summary of the weld overlay design and analysis as requested in the November 13, 2003 call (Attachment 5). Framatome-ANP requests that the document be withheld from public disclosure in accordance with 10 CFR 2.790(a)(4), An affidavit supporting this request is contained in Attachment 4. Attachment 5 to this letter contains the proprietary version of the analysis.

kOst) 7

Additional Information Concerning a Proposed Alternative Associated with the Use of a Weld Overlay November 20, 2003 Page 2 As requested in the Reference 1 letter, we request approval of the proposed alternative for the remainder of the ten-year interval.

If you have any questions, please contact us.

Very truly yours, Michael P. Gallagher Director, Licensing and Regulatory Affairs AmerGen Energy Company, LLC Attachments cc: H. J. Miller, Administrator, Region 1,USNRC USNRC Senior Resident Inspector, TMI D. Skay, USNRC Senior Project Manager File No. 01086

ATTACHMENT I RESPONSE TO ADDITIONAL QUESTIONS

Response To Additional Questions Attachment 1 Regarding Alternative Repair For Page 1 of 3 Surge Line Nozzle-To-Safe End Weld

References:

1) Letter from Michael P. Gallagher (AmerGen Energy Company, LLC), to U. S.

Nuclear Regulatory Commission, dated November 3, 2003

2) Letter from Michael P. Gallagher (AmerGen Energy Company, LLC), to U. S.

Nuclear Regulatory Commission, dated November 7, 2003

3) Letter from Michael P. Gallagher (AmerGen Energy Company, LLC), to U. S.

Nuclear Regulatory Commission, dated November 18, 2003 In the submittal dated November 3, 2003, the AmerGen Energy Company, LLC proposed a dissimilar metal weld overlay repair to the pressurizer line at Three Mile Island, Unit 1. On November 7, 2003, the licensee provided answers to questions the staff provided in a phone call on November 5, 2003. The staff is reviewing both submittals. In order to continue the review, the staff requests the following information:

Question:

1.0 In the November 3 submittal, Table 2 describes the acceptance standards for the completed weld overlay for complete bonding and minimum thickness as being per the weld overlay design. The weld overlay design is for minimum thickness.

Provide the acceptance standards for bonding and construction flaws.

Response

The acceptance standards for bonding are those provided in ASME Section Xl, 1995 Edition, through 1996 Addenda, IWB-3514-3, "Allowable Laminar Flaws". "Lack-of-bonding", if identified, will also be evaluated to ensure that the outer 25% of the original pipe wall thickness above the identified axial flaw can be adequately interrogated by the required angle beam examination. Generally, the radiography process does not lend itself to the detection of indications that are oriented parallel to the component/piping surface (e.g., lack-of-bond). The ultrasonic testing (UT) method using a straight beam (0 2L) is the process that would lend itself to the detection of lack-of-bonding indications.

Therefore, the proposed UT acceptance standards of IWB-3514-3 are the appropriate acceptance standards to evaluate lack-of-bond indications for this weld overlay application.

The volumetric acceptance standards for "construction flaws" are those provided in ASME Section Xl, 1995 Edition, through 1996 Addenda, IWB-3514-2, "Allowable Planar Flaws", applicable to Preservice Examination. Although the UT acceptance standards of IWB-3514-2 are different from those of Appendix B-1 (Draft ANSI B31.7, 1968 Errata) for radiography, the use of IWB-3514-2 UT acceptance standards are appropriate because UT is the proposed alternate examination method. This is consistent with the examination approach specified in paragraph (i) of Code Case N

Response To Additional Questions Attachment 1 Regarding Alternative Repair For Page 2 of 3 Surge Line Nozzle-To-Safe End Weld 504-2 as well as that of paragraph IWA-4600(a) of ASME Section XI, 1995 Edition, through 1996 Addenda.

Question:

2.0 In the November 3 submittal, Table 3 states that the examination volume will be the volume examined in the PDI demonstration. Provide a sketch showing cross-section with dimensions of the PDI inspection volume. Will the inspections include the ferritic base metal beneath the overlay? If not, explain why this area is not susceptible to crack growth?

Response

For the preservice inspection as noted in Table 2 of the Reference 1 submittal, the entire length for the full circumference of the overlay will be examined. The outer 25%

of the original pipe wall will also be examined to the maximum degree allowable by the weld overlay configuration. An estimated coverage map is provided in Attachment 1.

Future inspections will be covered as discussed in Table 3 including 1/2 inch on either side of the original weld. Inspection on either side of the original weld will find any postulated flaw extending into the stainless steel or carbon steel. The carbon steel is not expected to have any active degradation; therefore, interrogation of the 1/2 inch on either side of the original weld is conservative. This is based on past IGSCC experience in BWRs.

Question:

3.0 In the November 3 submittal, Table 3 states that the acceptance standards for the volumetric examination is that "No planar flaw extending into the structural weld overlay." In the November 7 submittal, the answer to question 3.0 states that Code required no flaw greater than 75% of the wall. In the sketch for question 2.0 above, (or separate sketch of the overlay and butt weld cross section) show the maximum height of the embedded flaw that would be within the Code acceptance.

Response

The overlay replaces the pressure boundary as discussed in our response to question 3b of the Reference 2 submittal. The maximum extent of cracking can go through the original pipe wall and through the first two diluted layers of the overlay; this material is not considered or credited as part of the new pressure boundary (see Attachment 3, "Schematic Showing Basis for Determination of Weld Overlay Thickness"). There can be no crack penetration into the structural portion of the overlay. The weld overlay re-establishes the 75% criteria established by the Code. The November 7 response to Question 3.0 relates to the design of the overlay thickness based upon the ASME Section Xl requirement that limits maximum flaw depth to 75% through-wall. The weld

Response To Additional Questions Attachment 1 Regarding Alternative Repair For Page 3 of 3 Surge Line Nozzle-To-Safe End Weld overlay repair was designed to meet this code requirement assuming the flaw depth extended through the original wall thickness plus the first two (2) diluted layers of weld overlay material.

Question:

4.0 In the November 3 submittal, Table 3 states that re-examination frequency will be the next two refueling outages and re-evaluated based on inspection results. In the November 7 submittal Table 1 the basis for the proposed alternative to IWA-4530(a) states that re-inspections frequencies have been established based on historical BWR experience. BWR experience is provided in the Electric Power Research Institute proprietary report TR-1 13932, "BWR Vessel and Internals Project, Technical Basis for Revisions to Generic Letter 88-01 Inspection Schedules (BWRVIP-75)," dated October 1999 and the NRC staff's safety evaluation was issued on May 14, 2002. Will the inspection frequency described in BWRVIP-75 as supplemented by the NRC staff's safety evaluation be the minimum inservice inspection frequency? If not, provided the criteria for establishing the inservice inspection frequency.

Response

Yes.

Question:

5.0 In the November 7 submittal, Table 1 states that all girth butt welds shall be examined 100% by radiography. The proposed examination is UT (November 3 submittal Table 1). Provide a discussion on the acceptability standards for construction flaws.

Response

See answer to question #1 above.

ATTACHMENT 2 ESTIMATED COVERAGE MAP

GE Nuclear Energy SR0010BM Weld Overlay Proposed Scan Coverages & Plots based on Design Input TMI Revision 0 11/18103 Prepared by S.C. Mortenson 11118/2003 1 of 9

I

'I' GE Nuclear Energy Proposed Scan Coverages K - Cross Sectionial

-Scan Direction- Area n 2 Percentage Total n/a 11.3 0 Lwave Axial 8.8 78%

45 Upstream Axial 8.7 77%

45 -Downstream Axial 8.7 77%

60 Upstream Axial 8.3 73%

60 Downstream Axial 8.6 76%

.70 Upstream Axial 7.7 68%

70 Downstream Axial 8.1 72%

Circumferential Scans (ea)l Circumferential 8.8 78%

11/18/2003 2of 9

GE NuclearEnergy 0 Lwave & Circumferenti31 Scans Il 11/18/2003 3 of 9

GE Nuclear Energy 45 Upstream 11/18/2003 4of 9

GE NuclearEnergy 45 Downstream 11118/2003 5of 9

I GE Nuclear Energy 60 Upstream I

11/18/2003 6of 9

\i!MV GE Nuclear Energy 60 Downstream I

I 11/1812003 7of 9

GE Nuclear Energy 70 Upstream 11/18/2003 8of 9

0 1 I GE Nuclear Energy k) GE Nuclear Energy 70 Downstream 11/18/2003 9 of 9

ATTACHMENT 3 SCHEMATIC SHOWING BASIS FOR DETERMINATION OF WELD OVERLAY THICKNESS

Weld Overlay Thickness, t WOLA Two Dilution Layers, tDL = 0.2" Original Wall, tw 03195,0 Postulated 360° Flaw Depth equals original pipe thickness and thickness of the two dilution layers.

Weld Overlay Thickness Defined by:

tw + tDL = 0.75 tW + tDL + tWOL Schematic Showing Basis for Determination of Weld Overly Thickness

ATTACHMENT 4 FRAMATOME-ANP AFFIDAVIT

AFFIDAVIT COMMONWEALTH OF VIRGINIA )

) ss.

CITY OF LYNCHBURG )

1. My name is Gayle F. Elliott. I am Manager, Product Licensing in Regulatory Affairs, for Framatome ANP ("FANP"), and as such I am authorized to execute this Affidavit.

2. 1am familiar with the criteria applied by FANP to determine whether certain FANP information is proprietary. I am familiar with the policies established by FANP to ensure the proper application of these criteria.

3. 1am familiar with the report, SIR-03-153, Revision 0, referenced in letter number 5928-03-20234 from Michael P. Gallagher, AmerGen Energy Company, LLC, to the U.S. Nuclear Regulatory Commission, dated November 20, 2003, entitled "Weld Overlay Design for the Hot Leg Nozzle to Surge Line Weld at Three Mile Island Unit 1" and referred to herein as "Document." Information contained in this Document has been classified by FANP as proprietary in accordance with the policies established by FANP for the control and protection of proprietary and confidential Information.

4. This Document contains information of a proprietary and confidential nature and is of the type customarily held in confidence by FANP and not made available to the public.

Based on my experience, I am aware that other companies regard information of the kind contained in this Document as proprietary and confidential.

5. This Document has been made available to the U.S. Nuclear Regulatory Commission in confidence with the request that the information contained In this Document be withheld from public disclosure.

6. The following criteria are customarily applied by FANP to determine whether information should be classified as proprietary:

(a) The information reveals details of FANP's research and development plans and programs or their results.

(b) Use of the information by a competitor would permit the competitor to significantly reduce its expenditures, in time or resources, to design, produce, or market a similar product or service.

(c) The Information includes test data or analytical techniques concerning a process, methodology, or component, the application of which results In a competitive advantage for FANP.

(d) The information reveals certain distinguishing aspects of a process, methodology, or component, the exclusive use of which provides a competitive advantage for FANP in product optimization or marketability.

(e) The information is vital to a competitive advantage held by FANP, would be helpful to competitors to FANP, and would likely cause substantial harm to the competitive position of FANP.

7. In accordance with FANP's policies governing the protection and control of information, proprietary information contained in this Document have been made available, on a limited basis, to others outside FANP only as required and under suitable agreement providing for nondisclosure and limited use of the information.

8. FANP policy requires that proprietary information be kept In a secured file or area and distributed on a need-to-know basis.

9. The foregoing statements are true and correct to the best of my knowledge, information, and belief.

SUBSCRIBED before me this a

• day of 2003.

a'-, e &6,:: 0. " - ) 24 I' f . t Ella F. Carr-Payne NOTARY PUBLIC, STATE OF VIRGINIA MY COMMISSION EXPIRES: 8131/05

-12 ELLA F. CARR-PAYNE Notary Public Commonwealth of VWginia My Commission Exps. Aug. 31,2006