ML032590929
| ML032590929 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/12/2003 |
| From: | Abney T Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| R08 030912 641 | |
| Download: ML032590929 (9) | |
Text
R08 030912 641 September 12, 2003 10 CFR 50.55a(a)(3)(i)
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop: OWFN P1-35 Washington, D.C. 20555-0001 Gentlemen:
In the Matter of )
Docket No. 50-259 Tennessee Valley Authority )
BROWNS FERRY NUCLEAR PLANT (BFN) - UNIT 1 - AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) SECTION XI, INSERVICE INSPECTION (ISI) PROGRAM - REQUEST FOR RELIEF PDI CLARIFICATION AND ADDITIONAL INFORMATION This letter provides clarification and changes to BFN Unit 1 request for relief PDI-2, regarding the examination volumes of Class 1 reactor vessel pressure retaining nozzle-to-vessel welds. TVA submitted PDI-2 request for relief by letter dated October 25, 2002, for the BFN Unit 1, ASME Section XI, Inservice Inspection program, first Ten-Year interval.
PDI-2 allows TVA to limit the extent of the examination volume for reactor pressure vessel nozzle-to-vessel welds to no more than one-half inch beyond the widest part of the weld. PDI-2 reduces the required weld examination volumes from those shown in the 1995 Edition, 1996 Addenda of the ASME Section XI Code, Subsection IWB, Figures IWB-2500-7(a) and (b), [i.e., one-half the vessel shell thickness beyond the widest part of the weld].
During its review of the BFN request for relief PDI-2, the NRC staff identified a question regarding the exact number
of welds that had received a preservice weld volume examination defined by T/2 (i.e., one-half the base material thickness). TVA and the NRC staff held a teleconference to discuss the staffs question.
U.S. Nuclear Regulatory Commission Page 2 September 12, 2003 As a result of that teleconference, TVA provided a response to the NRC question and a revised request for relief PDI-2 in a letter dated June 18, 2003. In a subsequent teleconference, the staff requested specific information regarding the BFN Unit 1 preservice and inservice RPV weld examinations. TVA is providing the requested information in the enclosure to this letter.
TVA seeks review of this request for relief by November 3, 2003, to support Unit 1 restart activities.
There are no new regulatory commitments in this letter. If you have any questions, please contact me at (256) 729-2636.
Sincerely, Original signed by:
T. E. Abney Manager of Licensing and Industry Affairs Enclosure cc (Enclosure):
(Via NRC Electronic Distribution)
Mr. Stephen J. Cahill, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970 Mr. Kahtan N. Jabbour, Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint, North (MS 08G9) 11555 Rockville Pike Rockville, Maryland 20852-2739
U.S. Nuclear Regulatory Commission Page 3 September 12, 2003 DTL:JWD:BAB Enclosure cc (Enclosure):
A. S. Bhatnagar, PAB 1E-BFN M. J. Burzynski, BR 4X-C G. F. Deaton, CMB 1B-BFN J. E. Maddox, LP 6A-C R. F. Marks, PAB 1C-BFN R. G. Jones, NAB 1A-BFN D. C. Olcsvary, LP 6A-C C. M. Root, PAB 1G-BFN J. R. Rupert, NAB 1A-BFN K. W. Singer, LP 6A-C M. D. Skaggs, POB 2C-BFN E. J. Vigluicci, ET 11A-K NSRB Support, LP 5M-C EDMS-K s:\\lic\\submit\\subs\\U1 PDI-2 RAI.doc
ENCLOSURE TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNIT 1 AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) SECTION XI, INSERVICE INSPECTION (ISI) PROGRAM (FIRST TEN-YEAR INSPECTION INTERVAL)
REQUEST FOR RELIEF PDI-2 RESPONSE TO NRC QUESTION TVA submitted request for relief, PDI-2, by letter dated October 25, 2002, for the BFN Unit 1, ASME Section XI, Inservice Inspection program, first Ten-Year interval. During its review of the BFN request, the NRC staff identified a question regarding the exact number of welds that had received a preservice weld volume examination defined by T/2 (i.e.,
one-half the base material thickness). As a result, TVA provided a response to the NRC question and a revised request for relief PDI-2 in a letter dated June 18, 2003. In a subsequent teleconference, the staff requested specific information regarding the BFN Unit 1 preservice and inservice RPV weld examinations. The NRC request, and the corresponding TVA response, is provided below.
NRC Question Provide a list of the reactor pressure vessel (RPV) welds within the scope of this request for relief, in table format, and show the results of the completed preservice and inservice weld examinations.
TVA Response The preservice examination report for Browns Ferry (BFN)
Unit 1, dated January 20, 1973, includes examination details for full penetration nozzle-to-vessel weld 4 inches in diameter and larger. The preservice examinations were not required by regulations, 10 CFR 50.55a(g)(1), given the BFN Unit 1 construction permit date of May 10, 1967, and were performed on a voluntary basis. The ultrasonic scan techniques and methods employed during preservice examinations
provided coverage of the 1/2T base material adjacent to the weld to the extent practical.
E-2 Eighteen of the BFN Unit 1 nozzle-to-vessel welds have been examined inservice to the extent practical, including the 1/2T base material, during the first interval. The welds examined inservice include at least one nozzle-to-vessel weld of each size/grouping for which relief is requested. There were no reportable indications identified by either the preservice or inservice examinations. The preservice and subsequent inservice examinations performed to date provide the justification basis for granting the relief specified in PDI-2 for BFN Unit 1.
The attachment to this enclosure provides a table listing the Unit 1 RPV welds represented within the scope of this request for relief. The table also provides the results of previous UT weld examinations (preservice and inservice), examination limitations, and major weld repair areas.
ATTACHMENT BFN UNIT 1 REACTOR PRESSURE VESSEL WELD EXAMINATIONS E-3 Component Welds Major Repair Areas (Note 2)
PSI Exam (Note 1)
Limitations (Note 3)
Scan Angles (Note 4)
ISI Exam (Note 5)
Limitations (Note 3)
Scans N1A-NV (28) 2 Yes - T/2 Yes, see note 0, 60 & 70 No n/a n/a N1B-NV (28) 4 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 0, 45, 60 & 70 N2A-NV (12) 2 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
No additional 0, 45, 60 & 70 N2B-NV (12) 2 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
No additional 0, 45, 60 & 70 N2C-NV (12) 3 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 0, 45 60 & 70 N2D-NV (12) 3 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 0, 45, 60 & 70 N2E-NV (12) 1 Yes - T/2 0, 60 & 70 No n/a n/a N2F-NV (12)
None identified Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 0, 45, 60 & 70 N2G-NV (12) 1 Yes - T/2 0, 60 & 70 No n/a n/a N2H-NV (12) 1 Yes - T/2 0, 60 & 70 No n/a n/a N2J-NV (12) 2 Yes - T/2 0, 60 & 70 Yes - T/2 (3/5)
No additional 0, 45 & 60 N2K-NV (12) 1 Yes - T/2 0, 60 & 70 No n/a n/a N3A-NV (26)
None identified Yes - T/2 0, 60 & 70 No n/a n/a N3B-NV (26)
None identified Yes - T/2 0, 60 & 70 No n/a n/a N3C-NV (26)
None identified Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 0, 45, 60 & 70 N3D-NV (26)
None identified Yes - T/2 0, 60 & 70 No n/a n/a N4A-NV (12) 2 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 45, 60 N4B-NV (12) 3 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 45, 60 N4C-NV (12) 3 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 45, 60 N4D-NV (12) 2 Yes - T/2 0, 60 & 70 Yes - T/2 (3/5)
No additional 0, 45, 60 & 70 N4E-NV (12) 2 Yes - T/2 0, 60 & 70 No n/a n/a N4F-NV (12) 3 Yes - T/2 0, 60 & 70 No n/a n/a N5A-NV (10) 2 Yes - T/2 0, 60 & 70 No n/a n/a N5B-NV (10) 2 Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
Minor @6:00 0, 45, 60 & 70 N6A-NV (6)
None identified Yes - T/2 0, 60 & 70 Yes - T/2 (2/4)
No additional 0, 45, 60 & 70 N6B-NV (6)
None identified Yes - T/2 0, 60 & 70 Yes - T/2 (3/6)
No additional 0, 45 & 60 N7-NV (4)
None identified Yes - T/2 0, 60 & 70 Yes - T/2 (3/6)
No additional 0, 45 & 60 N8A-NV (5)
None identified Yes - T/2 Not detailed 0, 45, 60 & 70 Yes - T/2 (2/4)
No additional 0, 45, & 60 N8B-NV (5)
None identified Yes - T/2 Not detailed 0, 45, 60 & 70 No n/a n/a N9-NV (4) 2 Yes - T/2 Yes, see note 0, 60 & 70 Yes - T/2 (2/4)
Insulation-Note 6 0, 45 & 60 N10-NV (2.5)
None identified No n/a n/a No n/a n/a 28 nozzle-to-vessel welds in the RPV shell and 3 nozzle-to-head welds in the RPV head (N6A, N6B, & N7)
E-4 Note 1: Preservice information is taken from the Magnaflux Final Report for BFN Unit 1 PSI/baseline, which was performed post RPV hydro.
Note 2: Repair information is from General Electrics BFN Unit 1 RPV Examination Plan. Items identified as Major Repair are greater than 10% of the base material thickness or if the discrepancy appeared significant to the reviewer. The majority of the repair areas were located in the weld region.
Note 3: The nozzle is a scan obstruction in a barrel-type configuration, transducer lift-off occurs at the nozzle-to-shell (or head) weld radius blend area.
Ultrasonic scans are conducted from the RPV shell (or head) side with the identified transducers.
Note 4: The transducer angles are listed. Scans from the RPV shell side include directions perpendicular and oblique to the weld and base material in addition to those scans conducted parallel to the weld. The oblique directions were not scanned on the RPV head due to curvature.
Note 5: Inservice data is from TVA records in the identified inspection period/outage cycle, e.g., 2/4 = 2nd period/outage Cycle 4.
Note 6: The insulation interferences noted on the inspection data sheets caused only minor scan limitations.