ML041920008

RAI, Category B-J Full Penetration Welds of Nozzles in Vessels, Branch Connection Welds, Nominal Pipe Size 4 or Larger

ML041920008
Person / Time
Site:	Catawba
Issue date:	07/06/2004
From:	Sean Peters NRC/NRR/DLPM/LPD2
To:	Jamil D Duke Energy Corp
Peters S, NRR/DLPM, 415-1842
References
TAC MC2209, TAC MC2210
Download: ML041920008 (56)

Text

July 6, 2004 Mr. D. M. Jamil Vice President Catawba Nuclear Station Duke Energy Corporation 4800 Concord Road York, SC 29745

SUBJECT:

CATAWBA NUCLEAR STATION, UNITS 1 AND 2 RE: REQUEST FOR ADDITIONAL INFORMATION (TAC NOS. MC2209 AND MC2210)

Dear Mr. Jamil:

By letter dated February 19, 2004, you submitted Request for Relief 04-CN-001 for Catawba Nuclear Station, Units 1 and 2. This relief request is associated with Category B-J full penetration welds of nozzles in vessels, branch connection welds, nominal pipe size 4 or larger.

The U. S. Nuclear Regulatory Commission technical staff has reviewed the request and has determined that additional information is required, as identified in the Enclosure.

We discussed these issues with your staff on June 24, 2004. Your staff indicated that you would attempt to provide your response at the earliest opportunity.

Please contact me at (301) 415-1842, if you have any questions on these issues.

Sincerely,

/RA/

Sean E. Peters, Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-413 and 50-414

Enclosure:

As stated cc w/encl: See next page

July 6, 2004 Mr. D. M. Jamil Vice President Catawba Nuclear Station Duke Energy Corporation 4800 Concord Road York, SC 29745

SUBJECT:

CATAWBA NUCLEAR STATION, UNITS 1 AND 2 RE: REQUEST FOR ADDITIONAL INFORMATION (TAC NOS. MC2209 AND MC2210)

Dear Mr. Jamil:

By letter dated February 19, 2004, you submitted Request for Relief 04-CN-001 for Catawba Nuclear Station, Units 1 and 2. This relief request is associated with Category B-J full penetration welds of nozzles in vessels, branch connection welds, nominal pipe size 4 or larger.

The U. S. Nuclear Regulatory Commission technical staff has reviewed the request and has determined that additional information is required, as identified in the Enclosure.

We discussed these issues with your staff on June 24, 2004. Your staff indicated that you would attempt to provide your response at the earliest opportunity.

Please contact me at (301) 415-1842, if you have any questions on these issues..

Sincerely,

/RA/

Sean E. Peters, Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-413 and 50-414

Enclosure:

As stated cc w/encl: See next page DISTRIBUTION:

PUBLIC OGC DClarke PDII-1 R/F ACRS SPeters SCoffin RHaag, RII DNaujock ADAMS Accession: ML041920008 NRR-088 OFFICE PDII-1/PM PDII-1/SC NAME SPeters SCoffin DATE OFFICIAL RECORD COPY

REQUEST FOR ADDITIONAL INFORMATION DUKE POWER COMPANY CATAWBA NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-413 AND 50-414 The U. S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensees submittal dated February 19, 2004, regarding a request for request associated with Category B-J full penetration welds of nozzles in vessels, branch connection welds, nominal pipe size 4 or larger.

The NRC staff has identified the following information that is needed to enable the continuation of its review.

1. On page 2 of the submittal, you reference the nozzle to branch connection weld 1NC22-WN8, but no further information is provided. Please provide the non-destructive examination worksheets and associated figures for this weld.

2. For the welds that you are requesting relief, identify the weld material. If a butter was used, identify the butter material. Identify the nominal reactor cooling system pipe diameter and the wall thickness for the branch connections.

3. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code)Section XI, Appendix III, III-4450 states Welds that cannot be examined from at least one side (edge) using the angle beam technique shall be examined by another volumetric method. On page 2 of your submittal, you state that the connection is not accessible from the inside surface and that radiography cannot be performed because of geometry. Discuss the radiography performed to satisfy Appendix III requirements and explain why radiography has not been proposed or considered.

4. On page 2 of the submittal, you indicate that the subject welds were volumetrically examined during preservice and the first 10-year inservice inspection (ISI) interval. Discuss the coverage achieved, transducers used, ultrasonic testing (UT) technique (manual/automatic), and availability of the actual data from the inspections. Describe the conditions that exist that have rendered UT ineffective for the second 10-year interval.

5. On page 2 of the submittal, your proposed alternative is to use liquid penetrant testing (PT) and visual testing (VT-2) in lieu of volumetric examinations. The Code-required PT is performed once per interval. Will the PT be performed more frequently than once per interval?

Discuss the PT and VT-2 examination frequency for the remaining ISI interval.

6. If UT examinations are not capable of providing reliable information of weld integrity, provide a discussion of the potential for flaws to develop in the weld area. Influences upon the weld region include: fluid temperature fluctuations, fluid direction (into or out of the connection nozzle), flow fluctuations, vibrations, cycling, water chemistry, etc.

7. Are any of these welds included in risk-informed examination requirements? Are there other locations with similar materials and operating conditions that can be volumetrically examined?

8. The ASME Code provides minimum prescriptive-based examination criteria in Section XI, Appendix III. In Appendix III, Supplement 4, Paragraph 4(c), the Code recommends licensees qualify examiners and procedures using welded samples and simulated or actual flaws located in positions where geometry may make them more difficult to detect. The purpose of the examination procedure qualification is to determine that the proposed examination technique is capable of detecting the specified flaws of interest and that the examination capabilities and limitations are identified.

In the first paragraph of page 2 of the submittal, you indicate that the demonstration used a mock-up of similar materials with flaw depths required by Section XI, Appendix VIII, Supplement 2, 1995 Edition with 1996 Addenda. The Supplement 2 flaw depths can be any through-wall depth and the inspection volume is the inner 1/3 of the through-wall depth. What are the specific flaw depths, orientations, and locations used for the demonstrations? Identify the flaw depths that can be effectively detected.

9. The ASME Code provides the minimum criteria for performing prescriptive-based UT. The licensee may use additional equipment and expertise to perform an examination. Extensive research, round-robin testing, and demonstrations have been performed on cast austenitic material using different transducer configurations (phase array, SAFT-UT, low frequency twin crystal, etc.) and data manipulation (computer) techniques. Discuss any other equipment and UT techniques that were considered and were determined ineffective for this application.

10. With current capabilities for detecting flaws at depths beyond the volume identified in Figure IWB-2500-11, what is the maximum acceptable IWB-3600 flaw depth for each of the subject welds? The maximum depth should include flaw growth (based on the different flaw types, such as, low/high cycle fatigue, creep, primary water stress corrosion cracking) between examinations. Discuss the effectiveness of using UT to detect the maximum flaw depth.

11. The inspectability of cast austenitic cast material is dependent on the material microstructure which is dependent on material cleanliness, second phase precipitates, super-cooled liquid, and heat extraction from the mold surface. Because of the variability between similar cast products, the results from a mock-up may also be a variable. Besides material specification and configuration, discuss other comparisons between the subject welds and the mock-up that support the existence of comparable microstructures.

Catawba Nuclear Station cc:

Lee Keller, Manager North Carolina Electric Membership Corp.

Regulatory Compliance P.O. Box 27306 Duke Energy Corporation Raleigh, North Carolina 27611 4800 Concord Road York, South Carolina 29745 Senior Resident Inspector U.S. Nuclear Regulatory Commission Lisa F. Vaughn 4830 Concord Road Duke Energy Corporation York, South Carolina 29745 Mail Code - PB05E 422 South Church Street Henry Porter, Assistant Director P.O. Box 1244 Division of Waste Management Charlotte, North Carolina 28201-1244 Bureau of Land and Waste Management Dept. of Health and Environmental Control Anne Cottingham, Esquire 2600 Bull Street Winston and Strawn Columbia, South Carolina 29201-1708 1400 L Street, NW Washington, DC 20005 Mr. R.L. Gill, Jr., Manager Nuclear Regulatory Issues North Carolina Municipal Power and Industry Affairs Agency Number 1 Duke Energy Corporation 1427 Meadowwood Boulevard 526 South Church Street P.O. Box 29513 Mail Stop EC05P Raleigh, North Carolina 27626 Charlotte, North Carolina 28202 County Manager of York County Saluda River Electric York County Courthouse P.O. Box 929 York, South Carolina 29745 Laurens, South Carolina 29360 Piedmont Municipal Power Agency Mr. Peter R. Harden, IV, Vice President 121 Village Drive Customer Relations and Sales Greer, South Carolina 29651 Westinghouse Electric Company 6000 Fairview Road Karen E. Long 12th Floor Assistant Attorney General Charlotte, North Carolina 28210 North Carolina Department of Justice P.O. Box 629 Mary Olson Raleigh, North Carolina 27602 Director of the Southeast Office Nuclear Information and Resource Service NCEM REP Program Manager 729 Haywood Road, 1-A 4713 Mail Service Center P.O. Box 7586 Raleigh, North Carolina 27699-4713 Asheville, North Carolina 28802

Catawba Nuclear Station cc:

Mr. T. Richard Puryear Owners Group (NCEMC)

Duke Energy Corporation 4800 Concord Road York, South Carolina 29745 Richard M. Fry, Director Division of Radiation Protection NC Dept. of Environment, Health, and Natural Resources 3825 Barrett Drive Raleigh, North Carolina 27609-7721 Henry Barron Group Vice President, Nuclear Generation and Chief Nuclear Officer P.O. Box 1006-EC07H Charlotte, NC 28201-1006