ML20210R903
| ML20210R903 | |
| Person / Time | |
|---|---|
| Issue date: | 08/13/1999 |
| From: | Bateman W NRC (Affiliation Not Assigned) |
| To: | Terry C AFFILIATION NOT ASSIGNED, NIAGARA MOHAWK POWER CORP. |
| References | |
| TAC-M94959, NUDOCS 9908170252 | |
| Download: ML20210R903 (4) | |
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%>1 UNITED STATES g
g j
NUCLEAR REGULATORY COMMISSION o
2 WASHINGTON, D.C. 20666 0001 s...../
I August 13,1999 j
Carl Terry, BWRVIP Chairman Niagara Mohawk Power Company Post Office Box 63 Lycoming, NY 13093
SUBJECT:
STAFF REEVALUATION OF TABLE 1 IN THE BWRVIP-07 REPORT (TAC NO. M94959)
Dear Mr. Terry:
By letter dated February 29,1996, as supplemented by letters dated July 17, May 21, and October 21,1996, and January 8,1997, you submitted the Electric Power Research Institute (EPRI) Report TR 105747, "BWR Vessel and Internals Project, Guidelines for Reinspection of BWR Core Shrouds (BWRVIP-07)," for NRC staff review and approval.
On September 15,1997, the staff issued its initial safety evaluation (SE) of the BWRVIP-07
)
report. The staff found the guidance to be generally acceptable but identified several open l
Issues. Representatives of the BWRVIP met with the NRC staff on November 5,1997, to discuss these issues and documented their proposed resolution in their submittal of November 26,1997. The staff completed its review of this additionalinformation and issued a supplement to its initial SE to close tho open issues by letter dated April 28,1998. The staff found that the revised guidance of the BWRVIP-07 report to be acceptable for inspection and assessment of the subject safety-related core shroud when the staff's conclusions are incorporated. The staff has also concluded that licensee implementation of the guidelines in BWRVIP-07, with modifications to address the staff's conclusions in the April 28,1998, SE, will provide an acceptable level of quality for examination and assessment of the safety-related components addressed in the BWRVIP-07 document.
l The remaining difference between the staff's final SE and the revised BWRVIP-07 document concerned the reinspection intervals (in years) for Category C plants, contained in Table 1, Core Shroud Reinspection Intervals for Category C Plants, of the BWRVIP-07 report. After discussions with the BWRVIP during the public meeting on July 21,1999, (see meeting summary dated August 10.1999), the staff agrees to the industry usage of the revised Tablo 1, attached.
The staff will re-evaluate this issue when the BWRVIP submits a consolidated and revised core shroud inspection and flaw evaluation guideline that incorporates the guidance presently 1
contained in the BWRVIP-01, -07, and -63 reports, and which will address the high fluer.ce i
levels expected at end of license.
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.T Carl Terry Please contact C. E. (Gene) Carpenter, Jr., of my staff at (301) 415-2169 if you have any further questions regarding this subject.
Sincerely, William H. Bateman, Chief Materials and Chemical Engineering Branch Division of Engineering Office of Nuclear Reactor Regulation
Enclosure:
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Karl W. Singer, Executive Chair Steve Lewis, Technical Chairman BWRVIP Assessment Task BWRVIP Assessment Task Tennessee Valley Authority Entergy PO Box 2000 P. O. Box 756 Decaltur, AL 35602 2000 Waterloo Road Port Gibson, MS 39150 D;'; Eaton, Executive Chair inspection CommFue Carl Larsen, Technical Chairman Entergy Operations, Inc.
BWRVIP Inspection Task PO Box 756, Waterloo Rd P.O. Box 157 Port Gibson, MS 39150-0756 Vernon, VT 05354 H. Lewis Sumner, Executive Chairman John Wilson, Technical Chairman BWRVIP Mitigation Task BWRVIP Mitigation Task Southern Nuclear Operating Co.
Clinton Power Station, M/C T-31C M/S BIN B051, PO Box 1295 P.O. Box 678 40 Inverness Center Parkway Clinton,IL 61727 Birmingham, AL 35201 Vaughn Wagoner, Technical Chairman Harry P. Salmon, Executive Chairman BWRVIP Integration Task BWRVIP Integration Task
. Carolina Power & Light Company New York Power Authority One Hannover Square 9C1 123 Main St., M/S 11 D P.O. Box 1551 White Plains, NY 10601-3104 Raleigh, NC 27612 George T. Jones, Executive Chair Bruce McLeod, Technical Chairman BWRVIP Repair Task BWRVIP Repair Task Pennsylvania Power & Light, Inc.
Southern Nuclear Operating Co.
M/S GEN A 61 Post Office Box 1295 2 N 9'" Street 40 inverness Center Parkway Allentown, PA 18101-1139 Birmingham, AL 35201 j
Robert Carter, EPRI BWRVIP Tom Mulford, EPRI BWRVIP Assessment Manager Integration Manager EPRI NDE Center Raj Pathania, EPRI BWRVlP P. O. Box 217097 Mitigation Manager 1300 W. T. Harris Blvd.
Ken Wolfe, EPRI BWRVIP Charlotte, NC 28221 Repair Manager Electric Power Research Institute Greg Selby, EPRI BWRVIP P. O. Box 10412 Inspection Manager 3412 Hillview Ave.
EPRI NDE Center Palo Alto, CA 94303 P. O. Box 217097 1300 W. T. Hanis Blvd.
James P. Pelletier, BWRVIP Liaison i
Charlotte, NC 28221 to EPRI Nuclear Power Council Nebraska Public Power District Joe Hagan, BWRVIP Vice Chairman 1200 Prospect Avenue PEPCO Energy Co.
PO Box 98 MC 62C-3 Brownville, NE 68321-0098 965 Chesterbrook Blvd Wayne, PA 19807-5691
4
=
Core Shroud Reinspection Intervals for Category C Plants (in years)
D Percent Stress ) = 1 ksi Stress (') = 3 ksi Stress ( ) = 6 ksi Crackingo.r>
Limit Load LEFM(*)
Limit Load LEFM(')
Limit Load LEFM(d) 1 0 to 10 '
10.0 10.0 10.0 10.0 10.0 10.0
>10 to 20 10.0 10.0 10.0 10.0 10.0 6.0
>20 to 25 6.0 6.0 6.0 6.0 6.0 6.0
>25 to 30 6.0 6.0 6.0 6.0 6.0
>30 Notes:
- 2. Cracking is defined as the totallength of as-found cracks as'a percentage of the totallength ins.pected for each weld. If the sizing uncertainty for the inspection method used exceeds (0.4" + 0.5*) in length at a flaw end, the amount above this should be included in the amount of cracking.
- 3. Stress values are for faulted loading conditions. Interpolation between stress values lo acceptable.
- 4. Applies to welds where neutron fluence is greater than 3 x 10 n/cm (E > 1MeV) 2
- 5. Linear extrapolation of the reinspection intervals is permitted up to a value of 10 ksi. Values should be capped (or rounded down) at values consistent with the approach in the above table.
- 6. Plant-specific analysis is required.
ENCLOSURE j