ML090210179
| ML090210179 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 01/29/2009 |
| From: | Martin R Plant Licensing Branch II |
| To: | Jerrica Johnson Southern Nuclear Operating Co |
| Martin, R E, NRR/DORL/LPLII-1, 415-1493 | |
| References | |
| TAC MD9742, TAC MD9743, TAC MD9744, TAC MD9745, TAC MD9746, TAC MD9747, TAC MD9748, TAC MD9749, TAC MD9750, TAC MD9751 | |
| Download: ML090210179 (7) | |
Text
January 29, 2009 Mr. J. Randy Johnson Vice President - Farley Joseph M. Farley Nuclear Plant 7388 North State Highway 95 Columbia, AL 36319
SUBJECT:
JOSEPH M. FARLEY NUCLEAR PLANT, UNITS 1 AND 2 - RE: REQUEST FOR ADDITIONAL INFORMATION THIRD 10-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN REQUESTS FOR RELIEF (TAC NOS. MD9742 THROUGH MD9751)
Dear Mr. Johnson:
The U.S. Nuclear Regulatory Commission (NRC) staff, with technical assistance from Pacific Northwest National Laboratory, has reviewed and evaluated the information provided by Southern Nuclear Operating Company, (the licensee) in its letter dated September 22, 2008, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML082670627), which proposed the following third 10-year interval inservice inspection program plan requests for relief (RR) for the Joseph M. Farley Nuclear Plant (FNP), Unit 1 (RR-62, RR-64, RR-65, RR-66, RR-67, RR-68 and RR-69), and FNP, Unit 2 (RR-61 and RR-62). Based on this review, it was determined that additional information is required to complete the NRC staff=s evaluation for the above RRs.
The NRC staff's request for additional information (RAI) is contained in the enclosed Technical Letter Report. In order for the staff to meet the established due date, we request that you respond to this RAI by May 1, 2009.
Sincerely,
/RA/
Robert E. Martin, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364
Enclosure:
Technical Letter Report cc w/encl: Distribution via ListServ
ML090210179 *Per Memo Dated OFFICE LPL2-1/PM LPL2-1/LA CPNB//BC LPL2-1/BC NAME RMartin SRohrer TChanr MWong DATE 01/27/09 01/22/09 01/14/09*
01/ 29/09
ENCLOSURE SOUTHERN NUCLEAR OPERATING COMPANY.
ALABAMA POWER COMPANY DOCKET NO. 50-348 AND 50-364 JOSEPH M. FARLEY NUCLEAR PLANT, UNIT 1 AND UNIT 2 REQUEST FOR ADDITIONAL INFORMATION TECHNICAL LETTER REPORT 1.0 SCOPE By letter dated September 22, 2008, Southern Nuclear Operating Company (licensee),
submitted the following requests for relief (RR) for Joseph M. Farley Nuclear Plant (FNP) Unit 1 (RR-62, RR-64, RR-65, RR-66, RR-67, RR-68 and RR-69); and FNP Unit 2 (RR-61 and RR-62).
The licensee requested relief from specific requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components for Farley, Unit 1 and Unit 2. The RRs apply to the third 10-year inservice inspection (ISI) interval, in which FNP, Units 1 and Units 2, adopted the 1989 Edition, with no addenda, of ASME Code Section XI as the code of record.
In accordance with Title 10 Code of Federal Regulation (10 CFR) 50.55a(g)(5)(iii), the licensee has submitted several RRs that cover specific ASME Code Class 1 and Class 2 component weld examinations. The ASME Code requires that 100 percent of the examination volumes described in ASME Code,Section XI, Tables IWB-2500-1 and IWC-2500-1, be completed.
The licensee has claimed that 100 percent of the ASME Code-required volumes are impractical to obtain at FNP Units 1 and Units 2. 10 CFR 50.55a(g)(5)(iii) states that when licensees determine that conformance with ASME Code requirements is impractical at their facility, they shall submit information to support this determination. The Nuclear Regulatory Commission (NRC) staff will evaluate such requests based on impracticality, and may impose alternatives, giving due consideration to public safety and the burden imposed on the licensee.
Pacific Northwest National Laboratory reviewed the information submitted by the licensee, and based on this review, determined the following additional information is required to complete the evaluation.
2.0 REQUEST FOR ADDITIONAL INFORMATION (RAI) 2.1 RR-62, RR-64, RR-65, RR-66, RR-67, RR-68 and RR-69, Piping Weld Examination, on FNP, Unit 1; and RR-61, and RR-62 on FNP Unit 2 State whether any outside diameter surface feature, such as weld crown, diametrical weld shrinkage, or surface roughness conditions caused limited volumetric coverage during the subject piping weld examinations. Discuss the efforts that were used to correct these conditions in order to maximize coverage.
2.2 RR-62, (FNP, Unit 1) ASME Code,Section XI, Examination Category R-A, Risk-Informed Piping Examinations The licensee has requested relief from the 100 percent ASME Code volumetric examination requirements for piping Weld ALA2-4540-32-RI, as defined by the FNP Unit 1,Risk-Informed Inservice Inspection Program. The basis for the RR is that 100 percent of the ASME Code-required inspection volume cannot be obtained because of component configuration and access restrictions.
The licensees submittal states that the subject weld root area was interrogated with both 45 and 70-degree shear waves (S-waves) looking for circumferential cracking. The licensees submittal further states that examinations were performed after the implementation of Appendix VIII (performance demonstration), and consisted of single-sided examinations from the pipe side of the weld.
Confirm that subject Weld ALA2-4540-32-RI was examined only using 45 and 70-degree S-wave techniques. If only S-wave techniques were used to examine the stainless steel weld, please explain why longitudinal wave (L-wave) examination techniques where not used as part of a best effort examination. The L-wave method has been shown capable of detecting planar (DP) inside diameter surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies1,2 recommend the use of both S-waves and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds.
It is noted that for RR-64, the licensee used both a 45-degree S-wave and a 60-degree refracted L-wave looking for circumferential cracking. RR-64 covers welds with similar access constraints.
It is also noted that the licensee uses RR-50 (in a previous submittal) as a precedent for this RR. However, a review of RR-50 shows that both S-wave and L-wave techniques were used in the examination of the welds.
2.3 RR-62 and RR-65 (FNP Unit 1), and RR-61 and RR-62 (FNP Unit 2), Examination Category R-A, Risk-Informed Piping Examinations Please indicate the risk informed ISI Item Number for each of the welds in these requests. For example, Examination Category R-A, Item R1.16, Elements Subject to Inter-granular Stress Corrosion Cracking, Full Penetration Piping Welds.
2.4 RR-65 (FNP, Unit 1) Examination Category R-A, Risk-Informed Dissimilar Metal Weld Piping Examinations RR-65 applies to primary system safe-end-to-nozzle dissimilar metal welds ALA1-4300-26ROM-RI, and ALA1-4300-27ROM-RI on a steam generator at FNP Unit 1. The NRC staff notes that Supplement 10 demonstrations are single-side (from the safe end) access qualifications. It is 1
F.V. Ammirato, X. Edelmann, and S.M. Walker, Examination of Dissimilar Metal Welds in BWR Nozzle-to-Safe End Joints, 8th International Conference on NDE in the Nuclear Industry, ASM International, 1987.
2 P. Lemaitre, T.D. Koble, and S.R. Doctor, PISC III Capability Study on Wrought-to-Wrought Austenitic Steel Welds: Evaluation at the Level of Procedures and Techniques, Effectiveness of Nondestructive Examination Systems and Performance Demonstration, PVP-Volume 317, NDE-Volume 14, ASME, 1995.
unclear why the licensee cannot examine the full ASME Code volume by using multiple ultrasonic techniques from the safe end side of these welds.
Please describe the ultrasonic inspection techniques that were used to examine the subject dissimilar metal welds and confirm that all of these techniques were demonstrated during qualification to Supplement 10 of the ASME Code,Section XI, Appendix VIII. Include discussion as to whether site-specific demonstrations occurred, and provide any technical justifications or reports resulting from this site-specific activity.
The sketches provided with RR-65 do not illustrate the amount of weld that was inspected or what inspection angle(s) were used during the ultrasonic examination. Please submit information in the form of sketches or technical descriptions that illustrate the inspection techniques (scan angles) and the amount of ASME Code coverage that was obtained by each of the techniques (scan angels) applied.
Discuss whether the use of advanced ultrasonic techniques such as phased array might significantly increase coverage for the subject welds.
2.5 RR-66 and RR-68 (FNP, Unit 1), ASME Code,Section XI, Examination Category B-A, Reactor Pressure Vessel (RPV) Welds RR-66 requests relief for the reactor pressure welds shown in the table below.
Table 1 - ASME Code,Section XI, Examination Category B-A ASME Code Item Weld ID Weld Type Coverage RR-66 B1.11 ALA1 -1100-8 Lower Shell / Bottom Head 84%
B1.21 ALA1-1100-15 Lower Head / Circumferential 25%
B1.22 ALA1-1100-10 Lower Head Meridional Seam 51%
B1.22 ALA1-1100-11 Lower Head Meridional Seam 80%
B1.22 ALA1-1100-12 Lower Head Meridional Seam 88%
B1.22 ALA1-1100-13 Lower Head Meridional Seam 19%
B1.22 ALA1-1100-14 Lower Head Meridional Seam 39%
B1.30 ALA1-1100-1 Flange-to-Upper Shell 68%
RR-68 B1.22 ALA1-1300-1 Meridional Plate Weld (Top Head) 59%
B1.22 ALA1-1300-2 Meridional Plate Weld (Top Head) 59%
B1.22 ALA1-1300-3 Meridional Plate Weld (Top Head) 59%
B1.22 ALA1-1300-4 Meridional Plate Weld (Top Head) 59%
The licensees submittal states:
ASME [Code,Section XI,] Item Numbers B1.11 and B1.30 listed above for
[ASME Code,Section XI,] Table IWB-2500-1, Examination Category B-A, require that 100% of the length of each weld be examined. However, ASME [Code,Section XI,] Item Numbers B1.21 and B1.22 listed above for [ASME Code,Section XI,] Table IWB-2500-1,
Examination Category B-A, requires that the accessible length of each weld be examined. Even though only the accessible length was required for [ASME Code,Section XI,] Item B1.21 and B1.22 welds, they were conservatively included.
It is unclear from the submittal whether the ultrasonic inspection coverage that was obtained for ASME Code,Section XI, Items B1.21 and B1.22, was a percentage of the total weld length or a percentage of the accessible weld length. State what percentage of the ASME Code-required accessible length of the welds for ASME Code,Section XI, Items B1.21 and B1.22, was achieved.
While the technical descriptions provided in RR-66 and RR-68 list the general bases for examination limitations, the descriptions do not state how the listed bases limit the examinations. As an example, Table RR-66 states that weld ALA1-1100-1 was limited due to the flange configuration, keyways and irradiation specimen slots. This does not state how or why the flange configuration, or other appurtenances, limits the examination. For each of the welds in RR-66 and RR-68, provide sketches or sufficient technical descriptions so that the reasons for the impracticalities are clear.
2.6 RR-67 (FNP, Unit 1) ASME Code,Section XI, Examination Category B-J, Item B9.11, Austenitic Steel Piping Welds The licensee has requested relief from the 100 percent ASME Code volumetric examination requirements for ASME Code, Class 1 Category B-J, austenitic piping weld ALA1-4103-4. The basis for the RR is that 100 percent of the ASME Code required inspection volume cannot be obtained because of the component configuration and an access restriction.
Confirm that this weld was examined using both S-wave and L-wave techniques. As stated in Section 2.2.1 above, the L-wave method has been shown capable of ID surface-breaking flaws on the far-side of wrought stainless steel welds.
2.7 RR-61 (FNP, Unit 2) ASME Code,Section XI, Category R-A, Class 2Carbon Steel Piping Welds The licensee has requested relief from the 100 percent ASME Code volumetric examination requirements for several ferritic steel piping welds. The NRC staff notes that ASME Code,Section XI, Appendix VIII, Supplement 3, demonstrations are acceptable for single-side weld access examinations (10 CFR 50.55a(b)(2)(xv)(A)(2). It is unclear why the licensee cannot examine the full ASME Code volume by using multiple ultrasonic techniques from the accessible sides of these welds.
Please confirm that the ultrasonic inspection techniques that were used to examine the subject welds were qualified to Supplement 3 of Appendix VIII, and that the inspection techniques were qualified for single-side access.
In addition, it appears that, by the use of multiple inspection angles, a higher level of volumetric coverage can be obtained. Discuss whether inspection volume coverage could be increased by using multiple (higher) inspection angles.
The licensee=s submittal summarizes limited examinations performed during the third 10-year ISI interval, and provides calculated coverage for each component. However, in order to show the impracticality of examining 100 percent of the ASME Code required volumes or surface areas, the licensees submittal provides only typical figures that do not describe or depict the specific limitations for each weld listed in Table RR-61.
Please submit detailed and specific information to support the basis for each limited examination in RR-61, and, therefore, demonstrate impracticality. Include descriptions (written and/or sketches, as necessary) of the interferences to applied nondestructive examination (NDE) techniques. As applicable, describe NDE equipment, show accessibility limitations, and discuss whether alternative methods or advanced technologies could be employed to maximize ASME Code coverage.
2.8 RR-62 (FNP, Unit 2), ASME Code,Section XI, Examination Category R-A, Risk-Informed Piping Examinations The licensee has requested relief from the 100 percent ASME Code volumetric examination requirements for piping welds, as defined by the FNP, Unit 2, Risk-Informed ISI Program. The basis for the request for relief is that 100 percent of the ASME Code-required inspection volume cannot be obtained because of component configuration and access restrictions.
The licensees submittal states that the subject weld root areas were interrogated with 45-degree S-wave looking for circumferential cracking. The licensees submittal further states that examinations were performed after the implementation of ASME Code,Section XI, Appendix VIII (performance demonstration), and consisted of single-sided examinations from the pipe side of the welds.
Confirm that the subject welds were examined only using 45-degree S-wave techniques. If only S-wave techniques were used to examine the stainless steel welds, please explain why L-wave examination techniques where not used as part of a best effort examination. As stated in Section 2.2.1 above, the L-wave method has been shown capable of ID surface-breaking flaws on the far-side of wrought stainless steel welds. Recent studies as noted in Section 2.2.1 of this RAI recommend the use of both S-wave and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds.