NL-10-0989, Fourth 10-Year Interval Lnservice Inspection Program Submittal of Relief Requests
ML101890572 | |
Person / Time | |
---|---|
Site: | Hatch ![]() |
Issue date: | 07/08/2010 |
From: | Ajluni M Southern Nuclear Operating Co |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
NL-10-0989 | |
Download: ML101890572 (54) | |
Text
Southern Nuclear Operating Company, Inc.
July 8,2010 SOUTHERN A.
COMPANY Docket Nos.: 50-321 NL-10-0989 50-366 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Ladies and Gentlemen:
Pursuant to 10 CFR 50.55a(g)(5)(iv), Southern Nuclear Operating Company hereby submits the enclosed relief requests for the Edwin I Hatch Nuclear Plant Units 1 and 2, Fourth 10-Year Intervallnservice Inspection Program. These relief requests are coverage relief requests where it is impractical to obtain more than 90 percent coverage and there is reasonable assurance of structural integrity.
The relief requests are requested to be approved by July 1, 2011.
This letter contains no NRC commitments. If you have any questions, please contact Jack Stringfellow at (205)992-7037.
Sincerely, M. J. Ajluni Manager - Nuclear Licensing MJA/PAHllac
U. S. Nuclear Regulatory Commission Log: NL~10-0989 Page 2
Enclosures:
- 2. ISI-RR-03, Hatch - Units 1 and 2, Pressure Retaining Welds in Stainless Steel Piping
- 3. ISI-RR-04, Hatch - Unit 2, Pressure Retaining Dissimilar Metal Piping Welds
- 5. ISI-RR-06, Hatch - Unit 2, Pressure Retaining Welds in Pump Casings
- 6. ISI-RR-07, Hatch - Unit 1, Welded Attachments for Piping
- 7. ISI-RR-08, Hatch - Unit 2, Pressure Retaining Dissimilar Metal Piping Welds
- 8. ISI-RR-09, Hatch - Unit 2, Pressure Retaining Welds in Inconel Piping
- 9. ISI-RR-10, Hatch ~ Unit 2, Pressure Retaining Dissimilar Metal Safe - End Welds
- 10. ISI-RR-11, Hatch Units 1 and 2, Pressure Retaining Welds in Stainless Steel Piping cc: Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. D. R. Madison, Vice President - Hatch Ms. P. M. Marino, Vice President - Engineering RTYPE: CHA02.004 U. S. Nuclear Regulatory Commission Mr. L. A. Reyes, Regional Administrator Mr. R. E. Martin, NRR Project Manager - Hatch Mr. E.D. Morris, Senior Resident Inspector - Hatch Mr. P.G. Boyle, NRR Project Manager
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 1 ISI-RR-02 Hatch - Unit 1 Reactor Vessel Shell-to-Flange Weld
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-02 Relief Request In Accordance with 10 CFR SO.SSa(g)(S)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 1, ASME Section XI Category 8-A, Item Number 81.30 reactor vessel shell-to-flange weld.
1811/C Low Alloy Steel - Inspected 02/25/2006
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code Requirements Examination Category 8-A, Table IW8-2500-1 of the 2001 Edition with 2003 addenda of the ASME Section XI Code requires a volumetric examination be performed on this weld. The examination volume is shown in ASME Section XI Figure IW8-2500-4 and includes essentially 100% of the weld length. The examinations were performed from the outside of the reactor vessel using manual examination procedures, personnel, and equipment qualified in accordance with Appendix VIII, Supplements 4 and 6, as amended by the conditions set forth in 10 CFR 50.55a. The use of Appendix VIII was allowed by alternative ISI-ALT-01, which was approved by NRC safety evaluation dated January 3,2006.
- 4. Impracticality of Compliance The ultrasonic examinations could only be performed from the shell side of the weld because of the weld and nozzle taper as shown in Figures 1 and 2. Ultrasonic examinations from tapered surfaces have not been qualified by the Performance Demonstration Initiative (PDI).
The composite ultrasonic examination coverage was calculated as 68.7% by examination personnel. Limitations and coverage for specific types of examinations is discussed below.
Circumferential Flaws Examinations from the shell side scanning for circumferential flaws, using the 60° Refracted Longitudinal (RL). (designated as 60° T on Figure 1) had a composite coverage of 79.4%.
This composite coverage was reduced by the presence of three permanently mounted thermocouples at 0°, 1100 , and 2700 which prevented scanning for about 6" around each thermocouple for a total of 18" of missed coverage. The weld length is 730.45", so the ISI-RR-02 Version 1.0 Page 1 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-02 thermocouples had a minimal impact on coverage (about 2.5% of the weld length). The composite coverage scanning for circumferential flaws with the thermocouple restrictions}
was calculated as 77.4%.
Examination coverage details are shown below which were derived from the coverage information provided on Figure 1.
- The inside surface area which is defined by the lower box in Figure 1 received 100%
coverage, minus the 2.5% interference from the thermocouples or 97.5% coverage.
- The middle of the examination volume which is defined by the middle box received 98%
coverage, minus the 2.5% interference from the thermocouples or 95.5% coverage.
- The near surface (located at the outside of the reactor vessel) which is defined by the upper box, received 55% coverage, minus the 2.5% coverage from the thermocouples or 52.5% coverage. Of this 52.5% coverage, the weld and a portion of the adjoining base material were examined.
Axial Flaws Examinations from the shell side scanning for axial flaws, using the 60° Refracted Longitudinal (RL), (designated as 60° P on Figure 2) had a composite coverage of about 50.4%. This composite coverage was reduced by the presence of the three thermocouples which prevented scanning for about 6" around each thermocouple. The weld length is 730.45", so the thermocouples only impacted 18" or about 2.5% of the weld length. The composite coverage scanning for axial flaws (including the thermocouple restrictions) was calculated as 49%.
- 5. Burden Caused by Compliance To appreciably increase the examination volume coverage of weld C-1 would require a redesign of the RPVflange, which would be an undue burden. Therefore, it is concluded that meeting the ASME Code requirement is impractical.
- 6. Proposed Alternative and Basis for Use A significant volume of the weld was examined and no unacceptable indications were found.
Coverage for circumferential flaws originating at the inside surface or middle of the examination volume was in excess of 90%. Additionally, the reactor vessel vertical welds and the reactor vessel accessible bottom head welds were examined using Appendix VIII techniques without any unacceptable indications; therefore, it is unlikely that any pattern of degradation exists in the reactor vessel that has gone undetected. This examination coverage along with VT -2 examinations associated with the Class 1 leakage test performed each refueling outage provide reasonable assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the UT examination of the subject area to the maximum extent practical, there is reasonable assurance of the structural integrity and safety of the weld because the information and data obtained from the volume examined provided sufficient ISI-RR-02 Version 1.0 Page 2 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-02 information to judge the overall integrity of the weld. Relief should be granted per 10 CFR 50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1,2006 through December 31,2015.
- 8. Precedents A similar request was previously approved for the 3rd Inservice Inspection Interval on July 20,2007.
- 9. References ADAMS Accession Number: ML071830018 ISI-RR-02 Version 1.0 Page 3 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 Fourth 10-Year Interval 10 CFR SO.SSa Request Number ISI-RR-02 Hatch 1 C*1 RPV to Flange ti,r NS E~lIm Vd%1'ml e 8 Ii Sq 1ft 1 >>>>,'' "m-=-.,-'""____"",",,,_ __
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HH__-i rl Figure 1 - Coverage For Circumferentially-Oriented Flaws ISI-RR-02 Version 1.0 Page 4 of S
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 10-Year Interval 10 CFR SO.SSa Request Number ISI-RR-02 Hatch 1 C-1 RPV to Flange tW* I'tS "l<&1'l VO'Jl".e " IlU, $q, !II"
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- 119 II<!
If""'" 15'1\.1 fi ..., lle,,1"'l<!! ~t3$q
&~' I'tS 1 ,Scan~.e<:i '" :lS Sq, In fV T*Scan ":T"""~ = 16" Sil T ,~ 15%Tl ~.oc 3'( S:;
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Figure 2 - Coverage For Axially-Oriented Flaws ISI-RR-02 Version 1.0 Page S of S
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 2 ISI-RR-03 Hatch - Units 1 and 2 Pressure Retaining Welds in Stainless Steel Piping
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-03 Relief Request In Accordance with 10 CFR SO.SSa(g)(S)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component's) Affected Class 1, ASME Section XI Category 8-J, Item 89.11, Pressure Retaining Welds in Stainless Steel Piping NPS 4 or Larger Circumferential Welds:
1G31-1 RWCUM-6-0 Inspected 06/11/2006 2831-1 RCM-28AO Inspected 02128/2009 2E11-1 RHRM-24A Inspected 02128/2009
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IW8-2500-1, Examination Category 8-J, Item 89.11 requires that essentially 100% of the weld length be examined by the volumetric and surface methods.
ASME Code Case N-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%; i.e.,
greater than 90% examination coverage is obtained.
ASME Code Case N-663, as an alternative for use by the NRC RG 1.147, Revision 15, states that in lieu of the surface examination requirements for the piping welds of Examination Category 8-F (NPS 4 and larger), 8-J (NPS 4 and larger). C-F-1. and C-F-2, surface examinations may be limited to areas identified by the Owner as susceptible to outside surface attack.
- 4. Impracticality of Compliance The examination limitations for the above welds are due to the design of components (e.g.,
valves and tees) which restricts the access for the ultrasonic examinations shown in Table RR-05-1. With one exception, the examinations are a one-side examination and it would be impractical to increase the coverage.
ISI-RR-03 Version 1.0 Page 1 of 6
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-03
- 5. Burden Caused by Compliance Compliance would require the replacement of the valves and tees with new components fabricated with a special design to allow examination.
- 6. Proposed Alternative and Basis for Use Per the NRC staff position located in Generic Letter 88-01, these welds are considered resistant to Intergranular Stress Corrosion Cracking (IGSCC) and are defined as Category A. Each weld was stress improved using the induction heating stress improvement (IHSI) or Mechanical Stress Improvement Process (MSIP) and are all protected by effective hydrogen water chemistry except for 2E11-1 RHRM-24A-13, which is not considered to be protected due to stagnant conditions. The ultrasonic examination performed from at least one side of the weld in conjunction with the resistant materials, the stress improvement, and the hydrogen protection provides reasonable assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the UT examination of the subject areas to the maximum extent practical. there is reasonable assurance of the structural integrity and safety of the welds because the information and data obtained from the volume examined provided sufficient information to judge the overall integrity of the welds.
Furthermore, a VT-2 visual examination on the subject welds are performed each refueling outage as part of the leakage test. During operation, leakage can be determined by the leakage detection system (LOS) located in the Drywell. The LOS is described in HNP-1 FSAR Section 4.10 and HNP-2 FSAR Section 4.10. Based on the above information, relief should be granted per 10 CFR 50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1.2006 through December 31,2015.
- 8. Precedents A similar request was previously approved for the 3rd Inservice Inspection Interval on July 20.2007.
- 9. References ADAMS Accession Number: ML071830010 ISI-RR-03 Version 1.0 Page 2 of 6
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-03 Table BR*()~__L Weld Number Description Coverage -------------
Basis for Limited Coverage Coverage was limited to a one-sided examination due to the proximity of the valve taper to the weld (Figure 1). Circumferential flaw coverage was obtained using 45° and 70° shear waves. Axial flaw coverage was 1G31-1 RWCUM-6-0-20 316NG Elbow to Valve 50%
limited to the elbow side. Per the requirements of 10 CFR 50.55a(b)(2)(xv)(A)(2) coverage is 50%. This weld was stress improved during the 1993 outag~lJsing the MSIP ~rocess Coverage was limited to a one sided examination due to the proximity of the valve taper to the weld (Figures 2 and 3). Circumferential flaw coverage was obtained using 45° and 60° shear waves. Axial flaw 2831-1 RCM-28AO-3 Valve to 316NG Elbow 50%
coverage was limited to the elbow side. Per the requirements of 10 CFR 50.55a(b)(2)(xv)(A)(2) coverage is 50%. This weld was stress improved during the 1984 outage using the IHSI ~rocess.
Coverage was limited due to the tee configuration. 100% coverage was obtained for axial flaws on both sides of the weld. On the elbow side, 100% coverage for circumferential flaws was obtained. Coverage on the 2E11-1 RHRM-24A-13 316NG Elbow to 316NG Tee 85.6% tee side for circumferential flaws was limited to 57%. Circumferential flaw coverage was obtained using 45° and 60° shear waves. Figure 4 shows the limitations of the coverage. This weld was stress improved duriQgthe1~~4outage uSillgthe IHSI ~rocess.
Note: NG refers to nuclear grade piping that is resistant to intergranular stress corrosion cracking ISI-RR-03 Version 1.0 Page 3 of 6
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-03 Figure 1 - Illustration of the Code Coverage Obtained for 1G31-1 RWCUM-6-D-20
\ I 50% Coverage Obtained Due to Single Sided Exam Figure 2 -Illustration of the Code Coverage Obtained for 2831*1 RCM-28AD-3 2631-1 RCM*28AD-3 FLOW Valve Elbow CODE CO\IERAGE OBTAINED
- 50%
ISI-RR-03 Version 1.0 Page 4 of 6
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 1O-Year Interval 10 CFR 50.55a Request Number ISI-RR-03 Figure 3 - Photograph of the Configuration of the Elbow to Valve - 2831-1 RCM-28AD-3 Valve Elbow Weld ISI-RR-03 Version 1.0 Page 5 of 6
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-03 Figure 4 - Limitations of Circumferential Flaw Scans from the Tee Side of the Weld 2E11-1 RHRM-24A-13 Limited Scan Area Pipe Circumference 2700 Limited Scan Area ISI-RR-03 Version 1.0 Page 6of6
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 3 ISI-RR-04 Hatch - Unit 2 Pressure Retaining Dissimilar Metal Piping Welds
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-04 Relief Request In Accordance with 10 CFR SO.SSa(g)(S)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 1, ASME Section XI Category 8-J, Item 89.11, Dissimilar Metal Pressure Retaining Welds in Piping I\IPS 4 or Larger Circumferential Welds 2821-1 FW-12AA-8 -Inspected 02/23/2009 The dissimilar metal weld connects a carbon steel pipe to an Inconel extension piece using Inconel weld material.
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IW8-2500-1, Examination Category 8-J, Item 89.11 requires that essentially 100% of the weld length be examined using the volumetric and surface methods.
Note: This weld is a Category 8-J dissimilar metal weld that was examined per Supplement 10 of Appendix VIII.
ASME Code Case 1\1-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, i.e.,
greater than 90% examination coverage is obtained.
ASME Code Case 1\1-663, as an alternative for use by the NRC RG 1.147, Revision 15, states that in lieu of the surface examination requirements for the piping welds of Examination Category 8-F (NPS 4 and larger), 8-J (NPS 4 and larger), C-F-1, and C-F-2, surface examinations may be limited to areas identified by the Owner as susceptible to outside surface attack.
- 4. Impracticality of Compliance As shown in Figure 1, this Inconel weld joins a carbon steel pipe to an Inconel extension piece. On the Inconel side of the weld, there is a weld overlay which extends to the edge of the weld. On the carbon steel side, there is a severe taper.
ISI-RR-04 Version 1.0 Page 1 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-04 Circumferential flaw (transverse) exams were performed by utilizing beam angles of 30°.
45°, 60°, and 70° refracted longitudinal waves and by utilizing a 45° shear wave for the carbon steel base material. These exams could only be performed from the upstream side of the weld due to the weld overlay obstruction; however, this exam was limited due to the taper. The examination procedure required that when examining from only one side of the weld. that two beam angles were required to pass through the volume for calculating Code credit. As shown in Figure 2, only about 30% of the volume was covered by two beam angles and therefore received Code credit. However, eighty-seven percent of the Code required examination volume (lower 1/3 rd of the volume) was examined for circumferential flaws with a minimum of one angle.
Axial flaw (parallel) examinations were performed utilizing 25°, 35°,45°, and 55° refracted longitudinal waves and by utilizing 35°, 45°, and 55° shear waves. These exams could only be performed from the upstream side of the weld due to the weld overlay obstruction. As shown in Figure 2, only about 30% of the volume was covered due to the geometry.
An automated Phased Array system was used to maximize the examination coverage; however composite Code coverage of the weld was only 30%. It is impractical to appreciably increase the Code coverage because of the tapered geometry and the presence of the overlay.
- 5. Burden Caused by Compliance Obtaining more coverage would require the replacement of the Feedwater nozzle safe-end configuration and associated thermal sleeve to eliminate the overlay obstruction or alternately the overlay would need to be extended over 2B21-1 FW-12AA-8.
- 6. Proposed Alternative and Basis for Use This weld has a mechanical stress improvement process (MSIP) performed on it in 1994 which mitigated the potential for stress corrosion cracking (SCC). With the SCC mitigation and the high level of coverage for circumferential flaws (with at least one beam angle), there is reasonable assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the UT examination of the subject area to the maximum extent practical, there is reasonable assurance of the structural integrity and safety of the weld because the information and data obtained from the volume examined provided sufficient information to judge the overall integrity of the weld.
Furthermore, a VT-2 visual examination on the subject weld is performed each refueling outage as part of the leakage test. During operation leakage can be determined by the leakage detection system (LOS) located in the Drywell. The LOS is described in HNP-2 FSAR Section 4.10. Therefore, relief should be granted per 10CFR50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1, 2006 through December 31, 2015.
ISI-RR-04 Version 1.0 Page 2 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-04
- 8. Precedents A similar request was previously approved for the 3rd Inservice Inspection Interval on July 20,2007.
- 9. References ADAMS Accession Number: M L07183001 0 ISI-RR-04 Version 1.0 Page 3 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch. Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-04 Figure 1 - Piping Layout l
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ISI-RR-04 Version 1.0 Page 4 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-04 Figure 2 - Amount of Code Coverage IIII j tIrn Axial Flaw Coverage
"''---,---.'- 10" 4$'
B888883 Cire Flaw Coverage __*_ _.",__ !)O' ISI-RR-04 Version 1.0 Page 5 of 5
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 4 ISI-RR-05 Hatch - Unit 2 Pressure Retained Welds in Carbon or Low Allow Steel Piping
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-05 Relief Request In Accordance with 10 CFR SO.SSa(g)(S)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 2, ASME Section XI Category C-F-2, Item C5.51, Circumferential Pressure Retaining Welds in Carbon or Low Alloy Steel Piping:
2E41-2HPCI-16-TS-18 Elbow to Tee Weld -Inspected 02128/2009
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IWC-2500-1, Examination Category C-F-2, Item C5.51 requires that 100%
of each weld requiring examination receive a surface and volumetric exam.
ASME Code Case N-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASIVIE Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, i.e.,
greater than 90% examination coverage is obtained.
ASME Code Case 1\J-663, as an alternative for use by the NRC RG 1.147, Revision 15, states that in lieu of the surface examination requirements for the piping welds of Examination Category B-F (NPS 4 and larger), B-J (NPS 4 and larger), C-F-1, and C-F-2, surface examinations may be limited to areas identified by the Owner as susceptible to outside surface attack.
- 4. Impracticality of Compliance Coverage was limited to a single side exam from the elbow side due to a machined taper on the tee. Scans for axial flaws were not required for this carbon steel weld. Scans for circumferential flaws were performed using 45° and 70° shear waves from the elbow side.
The total examined was 80% of the Code required examination volume. Figure 1 illustrates the weld crown, the tapered tee, the examination angles, and the coverage.
S. Burden Caused by Compliance Increasing the coverage would require the re-design of the tee to allow access from the tee side or for the weld crown to be leveled.
ISI-RR-05 Version 1.0 Page 1 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-05
- 6. Proposed Alternative and Basis for Use A volumetric examination was performed on the weld for eighty percent coverage. In addition, VT-2 visual examinations associated with the Class 2 leakage test are performed each inspection period for the weld, 2E41-2HPCI-16-TS-18. Therefore, based on the UT examination along with the VT-2 examination of the subject area to the maximum extent practical, there is reasonable assurance of the structural integrity and safety of the weld because the information and data obtained from the volume examined provided sufficient information to judge the overall integrity of the weld.
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1,2006 through December 31,2015.
- 8. Precedents None. This is the first examination of this weld performed per Appendix VIII.
- 9. References
!'Jone ISI-RR-05 Version 1.0 Page 2 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-05 Figure 1 - Illustration of the Welded Crown, Tapered Tee, and Examination Angles 2E41-2HPCI-16-TS-18 FLOW ELBOW CODE REOUIRED VOLUME", 0.2 SO. INCHES LIMITED DUE TO WELD CROWN 0.04 SO. INCHES 0.04 DIVIDED BY 0.2 '" 0.2 OR 20%
TOTAL VOLUME EXAMINED 0.16 SO. INCHES OR 30*,
ISI-RR-05 Version 1.0 Page 3 of 3
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 5 ISI-RR-06 Hatch - Unit 2 Pressure Retaining Welds in Pump Casings
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-OS Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component,s) Affected Class 2, ASME Section XI Category C-G, Item CS.10, Pressure Retaining Welds in Pump Casings:
2E11-2RHR-PMI-A - Residual Heat Removal (RHR) Pump A Inlet Nozzle - Carbon Steel Inspected 02128/2009 2E21-2CS-PMI-A - Core Spray (CS) Circumferential Pump A Inlet Nozzle Weld - Carbon Steel -- Inspected 02/28/2009
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IWC-2500-1, Examination Category C-G, Item CS.10 requires that 100%
welds in all components in each piping run examined under Examination Category C-F receive a Surface Examination. In case of multiple pumps of similar design, size, function, and service in a system, required weld examinations may be limited to all the welds in one pump in the same group or distributed among any of the pumps of the same group.
ASME Code Case N-4S0, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, i.e.,
greater than 90% examination coverage is obtained.
- 4. Impracticality of Compliance Coverage was limited for the Surface Examinations due to the proximity of concrete walls to the welds (Figure 1), 2E11-2RHR-PMI-A and 2E21-2CS-PMI-A. Surface Examination coverage was calculated to be SO% for 2E11-2RHR-PMI-A and 54% for 2E21-2CS-PMI-A.
Supplemental visual coverage was performed on each weld to achieve coverage of greater than 90%. A PT examination was considered, but due to the proximity of the concrete walls coverage surface preparation on the weld would have been limited. Thus, there would not have been a appreciable amount of coverage increase. Increasing the amount of surface coverage is impractical because of the concrete wall.
ISI-RR-OS Version 1.0 Page 1 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-06
- 5. Burden Caused by Compliance Increasing the surface examination coverage would require a redesign of the pumps and room to allow for additional space around the weld.
- 6. Proposed Alternative and Basis for Use Supplemental visual coverage was performed to increase the amount of coverage to greater than 90%. Furthermore, SI\JC will ensure there is no leakage coming from the area of the subject nozzle during the Leakage Test/Hydrostatic Test which is performed each period.
The surface examination combined with the VT-2 visual examination should provide reasonable assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the surface examination along with the VT -2 examination of the subject areas to the maximum extent practical, there is reasonable assurance of the structural integrity and safety of the welds because the information and data obtained from the area examined provided sufficient information to judge the overall integrity of the welds. Therefore, relief should be granted per 10 CFR 50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1, 2006 through December 31, 2015.
- 8. Precedents None. This is the first relief requested for these welds.
- 9. References None ISI-RR-06 Version 1.0 Page 2 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-06 Figure 1 - Typical photograph of the concrete proximity of the concrete walls to the examination area.
Concrete Surroundings ISI-RR-06 Version 1.0 Page 3 of 3
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 6 ISI-RR-07 Hatch - Unit 1 Welded Attachments for Piping
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-07 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
--I nservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 1, ASME Section XI Category 8-K, Item 810.20, Welded Attachments for Piping:
1E41-1 HPCI-10-D-7HL-8-1 and 2 - Carbon Steel-Inspected 02/28/2008
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IW8-2500-1, Examination Category 8-K, Item 810.20 requires that essentially 100% of the length of the attachment weld on each attachment subject to examination be examined using the surface method.
ASME Code Case N-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, i.e.,
greater than 90% examination coverage is obtained.
- 4. Impracticality of Compliance The configuration consists of two lugs welded to the pressure retaining boundary with insufficient distance between them to perform a complete examination (Figure 1). Three sides of each lug were examined for a total of 54% coverage. Increasing coverage is impractical.
- 5. Burden Caused by Compliance Compliance would require replacement of the existing lugs with new lugs fabricated with a special design to allow examination.
- 6. Proposed Alternative and Basis for Use The surface examination performed on three sides of each lug should provide assurance that unallowable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the surface examination of the subject areas to the maximum extent practical, there is reasonable assurance of the ISI-RR-07 Version 1.0 Page 1 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-07 structural integrity and safety of the welds because the information and data obtained from the surface examined provided sufficient information to juqge the overall integrity of the welds.
Furthermore, a VT-2 visual examination on the subject weld is performed each refueling outage as part of the leakage test. During operation, leakage can be determined by the leakage detection system (LDS) located in the Drywell. The LDS is described in HNP-1 FSAR Section 4.10. Based on the above information, relief should be granted per 10 CFR 50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1, 2006 through December 31, 2015.
- 8. Precedents A similar request, though somewhat different, was previously approved for the 3'd Inservice Inspection Interval on July 20,2007.
- 9. References ADAMS Accession Number: ML071830010 ISI-RR-07 Version 1.0 Page 2 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 1 Fourth 10-Year Interval 10 CFR SO.SSa Request Number ISI-RR-07 Figure 1 - Drawing of Lugs on Piping
...,,------6 1
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All,.. qvf l OI.~it.,61J l f////III I I / I / I _L I I I I 1 T
~.,
)
,It ______ -+)
1E41-1HPCI-10-D-7HL-1 and 2 ISI-RR-07 Version 1.0 Page 3 of 3
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 7 ISI-RR-08 Hatch - Unit 2 Pressure Retaining Dissimilar Metal Piping Welds
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-08 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 1, ASME Section XI Category 8-J, Item 89.11, Dissimilar Metal Pressure Retaining Welds in Piping NPS 4 or Larger Circumferential Welds, 2E11-1 RHRM-20RS-3 Stainless Steel Elbow to Carbon Steel Pipe Weld - Inspected 02/28/2009
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IW8-2500-1, Examination Category 8-J, Item 89.11 requires that essentially 100% of the weld length be examined by the volumetric and surface methods.
ASME Code Case N-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, i.e.,
greater than 90% examination coverage is obtained.
ASME Code Case N-663, as an alternative for use by the NRC RG 1.147, Revision 15, states that in lieu of the surface examination requirements for the piping welds of Examination Category 8-F (NPS 4 and larger), 8-J (NPS 4 and larger), C-F-1, and C-F-2, surface examinations may be limited to areas identified by the Owner as susceptible to outside surface attack.
- 4. Impracticality of Compliance The examination coverage was limited due to taper created by the difference in the outside diameter of the elbow versus the outside diameter of the pipe (Figure 1). 8ased on the configuration of the weld, it is impractical to appreciably increase the coverage. Composite Code coverage was 87%. Examinations were performed as follows:
- Circumferentially-oriented flaw coverage was obtained from both the upstream and downstream sides of the weld using a 45°/60° Refracted Longitudinal Wave (RL) with 100% Code coverage (Figure 1).
ISI-RR-08 Version 1.0 Page 1 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR SO.SSa Request Number ISI-RR-Oa
- The base material was examined using a 4So shear wave with 100% coverage (Figure 2).
- Axially-oriented flaw coverage was obtained from both the downstream side and the upstream side of the weld using a 4So RL with 61 % Code (Figure 3).
- 5. Burden Caused by Compliance Compliance would require the replacement of the elbows with new components fabricated with a special design to allow examination.
- 6. Proposed Alternative and Basis for Use Although the ultrasonic examination was limited for axially-oriented flaws the circumferential flaw coverage of the weld joint was scanned from both sides with both the 4So RL transducer and the 60° RL transducer for 100% coverage. This coverage provides assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the UT examination of the subject area to the maximum extent practical, there is reasonable assurance of the structural integrity and safety of the weld because the information and data obtained from the volume examined provided sufficient information to judge the overall integrity of the weld.
Furthermore, a VT-2 visual examination on the subject welds is performed each refueling outage as part of the leakage test. During operation leakage can be determined by the leakage detection system (LOS) located in the Drywell. The LOS is described in HNP-2 FSAR Section 4.10. Based on the above information, relief should be granted per 10CFRSO.SSa(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1,2006 through December 31, 201S.
- 8. Precedents None. This is the first examination of this weld performed per Appendix VIII.
- 9. References None ISI-RR-oa Version 1.0 Page 2 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 1O-Year Interval 10 CFR 50.55a Request Number ISI-RR-08 Figure 1 - 45°/60° RL Axial Scans for Circumferential Oriented Flaws FlON 2E11-1 FHRM-2)RS-3 60 45 Cl ELSON PIPE 10CPk emE FEOUlfED VOlUM: EXAtJlN::D 45, 60 R AXIAL DRECTIC't'4 ISI-RR-08 Version 1.0 Page 3 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-08 Figure 2 - 45° Shear Wave Scan for Base Material Flaws 2E11.1RHRM-2JRS3 45 CL
~45
-r'------.....-----~'-----~
ElBOW PiPE EXAMIIIED 100% REOUIRED BASE MATERIAL WITH 45 SHEAR WAVE IIOTE: UTILIZED SKEWS FOR CIRC COVERAGE ISI-RR-08 Version 1.0 Page 4 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-08 Figure 3 - 45° RL Circumferential Scan for Axial Oriented Flaws 2E11*1 ~RM-2)RS-3 FLON 45 Cl ELBOW PIA::
--~------_ _ _--l..._ _ _- -. \,1 I TOTAL IAtLOLENGrH :62.S"fTOTAL EXAMAREAWIDrH =25" TOTAL EXAMAREA HBGHT '" 0.4" TOT AL CXX>E REQUREDEXAMVQ.Utt.tE = 625 CUBIC IP-CHESI EXAM\QlUM:. IS (BSTRUCTED FOR ALENGrti<F 47" 47"LENGrH X 1.3"WIDTH X .4"HEI3HT =24ACU9C INOiES!24,4DIVICEO BY 625 =3~ RlC'RCDIRECTI~ LlMTED TOTAL EXAMNED= 61 ISI-RR-08 Version 1.0 Page 5 of 5
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Reg uests Enclosure 8 ISI-RR-09 Hatch - Unit 2 Pressure Retaining Welds in Inconel Piping
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-09 Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 1, ASME Section XI Category B-J, Item B9.11, Pressure Retaining Welds in Piping NPS 4 or Larger Circumferential Welds 2B21-1 FW-12BC-12 -Inconel Safe End Extension to Inconel Safe End -Inspected 02128/2009
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IWB-2500-1, Examination Category B-J, Item B9.11 requires that essentially 100% of the weld length be examined by the volumetric and surface methods.
ASME Code Case N-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, i.e.,
greater than 90% examination coverage is obtained.
ASME Code Case N-663, as an alternative for use by the NRC RG 1.147, Revision 15, states that in lieu of the surface examination requirements for the piping welds of Examination Category B-F (NPS 4 and larger), B-J (NPS 4 and larger), C-F-1, and C-F-2, surface examinations may be limited to areas identified by the Owner as susceptible to outside surface attack.
- 4. Impracticality of Compliance Axial flaw examination coverage was limited due to a taper on the downstream piping (Figure 1). The Inconel weld joins an Inconel safe end to an Inconel safe end extension.
Based on the configuration of the weld, it is impractical to appreciably increase the coverage. Composite Code coverage was 86.5%. Examinations were performed as follows:
- Circumferentially-oriented flaw coverage was obtained from both the upstream and downstream sides of the weld using a 30°, 45°, 60° and 70° Refracted Longitudinal Wave ISI-RR-09 Version 1.0 Page 1 of 4
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-09 (RL) and a 45° shear wave. Code coverage obtained for circumferentially-oriented flaws was 100% .
- Axially-oriented flaw coverage was obtained utilizing 25°,35°,45°, and 55° RL and 35°,
45°, and 55° shear waves. Downstream axially-oriented flaw examinations were limited due to the safe end configuration (Figure 2). Code coverage obtained for axially-oriented flaws was 73%.
- 5. Burden Caused by Compliance Compliance would require the replacement of the tapered piping with new piping fabricated with a special design to allow examination.
- 6. Proposed Alternative and Basis for Use Although the ultrasonic examination was limited for axially-oriented flaws, the circumferential flaw coverage of the weld joint was scanned from both sides for 100% coverage. This 86.5% composite coverage along with 100% circumferential flaw coverage provides reasonable assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the UT examination of the subject area to the maximum extent practical, there is reasonable assurance of the structu ral integrity and safety of the weld because the information and data obtained from the volume examined provided sufficient information to judge the overall integrity of the weld.
Furthermore, a VT-2 visual examination on the subject welds is performed each refueling outage as part of the leakage test. During operation, leakage can be determined by the leakage detection system (LOS) located in the Drywell. The LOS is described in HNP-2 FSAR Section 4.10. Based on the above information, relief should be granted per 10 CFR 50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1,2006 through December 31,2015.
- 8. Precedents None. This is the first examination of this weld performed per Appendix VIII.
- 9. References None ISI-RR-09 Version 1.0 Page 2 of 4
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-09 Figure 1 -Illustration of Taper on Downstream Piping Component Flow ct Upstream Downstream Component Component ISI-RR-09 Version 1.0 Page 3 of 4
Southern Nuclear Operating Company I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR SO.SSa Request Number ISI-RR-09 Figure 2 - Illustration of Limited Axial Flaw Exam Coverage
.----~------
Scan r Axial flaws is lim ited due t taper, unable to maintain contact in this area.
No coverage ISI-RR-09 Version 1.0 Page 4 of4
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 9 ISI-RR-10 Hatch - Unit 2 Pressure Retaining Dissimilar Metal Safe - End Welds
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-lO Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 1, ASME Section XI Category B-F, Item B5.10, Pressure Retaining Dissimilar Metal Welds in Vessel Nozzle-to-Safe End Welds NPS 4 or Larger:
2E21-1CS-10A-21 -Inspected 02/26/2009 2E21-1 CS-1 OB Inspected 02125/2009 The dissimilar metal weld consists of a Low Alloy Steel Safe End to an Inconel Buttered Nozzle.
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IWB-2500-1, Examination Category B-F, Item B5.10 requires that essentially 100% of the weld length be examined by the volumetric and surface methods.
ASME Code Case N-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, Le.,
greater than 90% examination coverage is obtained.
ASME Code Case N-663, as an alternative for use by the NRC RG 1.147, Revision 15, states that in lieu of the surface examination requirements for the piping welds of Examination Category B-F (NPS 4 and larger), B-J (NPS 4 and larger), C-F-1, and C-F-2, surface examinations may be limited to areas identified by the Owner as susceptible to outside surface attack.
- 4. Impracticality of Compliance Examination coverage for both welds was limited due to weld shrinkage at the weld toe.
Based on the configuration of the weld, it is impractical to appreciably increase the coverage. Composite Code coverage was 86.5%. Examinations were performed as follows:
ISI-RR-10 Version 1.0 Page 1 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-10
- Circumferentially-oriented flaw coverage was obtained from both the upstream and downstream sides of the weld using a 30°,45° ,60° and 70° Refracted Longitudinal Wave (RL) and a 45° shear wave. Code coverage obtained for circumferentially-oriented flaws was 100%.
- Axially-oriented flaw coverage was performed utilizing 25°, 35°,45°, and 55° RL and 35°,
45°, and 55° shear waves. Downstream axially-oriented flaw examinations were limited due to the safe end configuration (Figure 1). Code coverage obtained for axially-oriented flaws was 73%.
- 5. Burden Caused by Compliance Compliance would require the weld to receive an overlay, the weld to be replaced, or the additional weld material be added to the weld shrinkage at the weld toe.
- 6. Proposed Alternative and Basis for Use Although the ultrasonic examination was limited for axially-oriented flaws, the circumferential flaw coverage of the weld joint was scanned from both sides for 100% coverage. This provides reasonable assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the UT examination of the subject areas to the maximum extent practical, there is reasonable assurance of the structural integrity and safety of the welds because the information and data obtained from the volume examined provided sufficient information to judge the overall integrity of the welds.
Furthermore, a VT-2 visual examination on the subject welds is performed each refueling outage as part of the leakage test. During operation leakage can be determined by the leakage detection system (LDS) located in the Drywell. The LDS is described in HNP-2 FSAR Section 4.10. Based on the above information, relief should be granted per 10 CFR 50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1, 2006 through December 31, 2015.
- 8. Precedents None. These are the first examinations of these welds performed per Appendix VIII.
- 9. References None ISI-RR-10 Version 1.0 Page 2 of 3
Southern Nuclear Operating Company Plant Edwin I. Hatch, Unit 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-10 Figure 1 - Illustration of the Limited Code Coverage for Axial Oriented Flaws Scan for Axial flaws is limited due to shrinkage at the weld toe, unable to maintain contact in this area.
No coverage ISI-RR-10 Version 1.0 Page 3 of 3
Edwin I. Hatch Nuclear Plant-Units 1 and 2 Fourth 10-Year Intervallnservice Inspection Program Submittal of Relief Requests Enclosure 10 ISI-RR-11 Hatch - Units 1 and 2 Pressure Retaining Welds in Stainless Steel Piping
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-11 Relief Request In Accordance with 10 CFR SO.SSa(g)(S)(iii)
--Inservice Inspection Impracticality-
- 1. ASME Code Component(s) Affected Class 1, ASME Section XI Category 8-J, Item 89.11, Pressure Retaining Welds in Piping NPS 4 or Larger Circumferential Welds:
1831-1 RC-128R-A Stainless Steel Piping-Inspected 03/10/2006 2G31-1 RWCUM-6-0 Austenic Steel Piping - Inspected 03/03/2009 2G31-1 RWCUM-6-0 Austenic Steel Piping - Inspected 02127/2009 2G31-1 RWCUM-6-0 Austenic Steel Piping -Inspected 02/28/2009
2. Applicable Code Edition and Addenda
ASME Section XI, 2001 Edition through the 2003 Addenda.
- 3. Applicable Code RequirementsSection XI, Table IW8-2500-1, Examination Category 8-J, Item 89.11 requires that essentially 100% of the weld length be examined by the volumetric and surface methods.
ASME Code Case N-460, as an alternative for use by the NRC RG 1.147, Revision 15, states that a reduction in examination coverage due to part geometry or interference for the ASME Class 1 or 2 weld is acceptable provided that the reduction is less that 10%, i.e.,
greater than 90% examination coverage is obtained.
ASME Code Case N-663, as an alternative for use by the NRC RG 1.147, Revision 15, states that in lieu of the surface examination requirements for the piping welds of Examination Category 8-F (NPS 4 and larger), 8-J (NPS 4 and larger), C-F-1, and C-F-2, surface examinations may be limited to areas identified by the Owner as susceptible to outside surface attack.
- 4. Impracticalitv of Compliance The examination limitations for the above welds are due to the desjgn of components (e.g.,
penetration, valve, and sweepolet) which restricts the access for the ultrasonic examinations shown in Table RR-12-1. With few exceptions, the examinations are primarily a one-side examination from the pipe side of the weld and it would be impractical to increase the coverage.
ISI-RR-11 Version 1.0 Page 1 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-11
- 5. Burden Caused by Compliance Compliance would require the replacement of the existing valves, and tees with new components fabricated with a special design to allow examination.
- 6. Proposed Alternative and Basis for Use Per the NRC staff position located in Generic Letter 88-01 these welds are considered susceptible to Intergranular Stress Corrosion Cracking (IGSCC), but the IGCSS was mitigated by stress improvement after more than two cycles of operation. These welds are defined as Category C. Each weld was stress improved using the induction heating stress improvement (IHSI) and are all protected by effective hydrogen water chemistry. The ultrasonic examination performed from at least one side of the weld in conjunction with the stress improvement and the hydrogen protections should provide reasonable assurance that unacceptable flaws have not developed in the subject weld or that they will be detected and repaired prior to the return of service. Therefore, based on the UT examination of the subject areas to the maximum extent practical, there is reasonable assurance of the structural integrity and safety of the welds because the information and data obtained from the volume examined provided sufficient information to judge the overall integrity of the welds.
Furthermore, a VT-2 visual examination on the subject welds are performed each refueling outage as part of the leakage test. During operation leakage can be determined by the leakage detection system (LOS) located in the Drywell. The LOS is described in HNP-1 FSAR Section 4.10 and HNP-2 FSAR Section 4.10. Based on the above information, relief should be granted per 10CFR50.55a(g)(6)(i).
- 7. Duration of Proposed Alternative The proposed alternative is applicable for the 4th Inservice Inspection Interval, extending from January 1, 2006 through December 31, 2015.
- 8. Precedents A similar request was previously approved for the 3rd Inservice Inspection Interval on July 20,2007.
- 9. References ADAMS Accession Number: ML071830010 ISI-RR-11 Version 1.0 Page 2 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-11 Table RR-12-1 Weld Number Description Coverage Basis for Limited Coverage Coverage was limited to a one-sided examination due to the proximity of the sweepolet taper to the weld (Figure 1). Circumferential flaw coverage was obtained using 60° shear waves and 60° Refracted I 1B31-1 RC-12BR-A-1 304 Pipe to 304 Sweepolet 50%
Longitudinal Waves. Axial flaw coverage was limited to the pipe side.
Per the requirements of 10 CFR 50.55a(b)(2)(xv)(A)(2) coverage is 50%.
This weld was stress improved in 1985 usinq the IHSI process.
Coverage was limited to a one-sided examination due to the proximity of .
the penetration taper to the weld (Figure 2). Circumferential flaw I coverage was obtained using 45° and 70° shear waves. Axial flaw 2G31-1 RWCUM-6-0-15 316NG Pipe to Penetration 50%
coverage was limited to the pipe side. Per the requirements of 10 CFR 50.55a(b)(2)(xv)(A)(2) coverage is 50%. This weld was stress improved during the 1984 outage usinq the IHSI process.
Coverage was limited to a one sided examination due to the proximity of the valve taper to the weld (Figure 3). Circumferential flaw coverage was obtained by the use of 45° and 70° shear waves. Axial flaw 2G31-1 RWCUM-6-0-16 316NG Pipe to Valve 50%
coverage was limited to the pipe side. Per the requirements of 10 CFR 50.55a(b)(2)(xv)(A)(2) coverage is 50%. This weld was stress improved during the 1984 outage using the IHSI process.
Coverage was limited to a one sided examination due to the proximity of the valve taper to the weld (Figure 4). Circumferential flaw coverage was obtained by the use of 45° and 67° shear waves for coverage of 2G31-1 RWCUM-6-0-17 Valve to Penetration 50% 50%. Axial flaw coverage was limited to the penetration side. Per the requirements of 10 CFR 50.55a(b)(2)(xv)(A)(2) coverage is 50%. This weld was stress improved during the 1984 outage using the IHSI L-. PiQcess.
Note: NG refers to nuclear grade piping that is resistant to intergranular stress corrosion cracking ISI-RR-11 Version 1.0 Page 3 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR SO.SSa Request Number ISI-RR-11 Figure 1 -Illustration ofthe Weld Geometry for 1B31-1RC-12BR-A-1 1 B31-R-'J RC-12BR-A-1 Sweepolet \
\
\
\ /
"\
\ .I
- ' ", Pipe 50% COVERAGE OBTAINED DUETO SINGLE SIDED EXAM Figure 2 - Illustration of the Code Coverage Obtained for 2G31-1 RWCUM-6-D-1S 2G31-1 RWCUM..f3-D-15 FLOW
---1 PIPE 50% COVERAGE OBTAINED DUE TO StNGlE SIDED EX.AA4 ISI-RR-11 Version 1.0 Page 4 of 5
Southern Nuclear Operating Company Plant Edwin I. Hatch, Units 1 and 2 Fourth 10-Year Interval 10 CFR 50.55a Request Number ISI-RR-11 Figure 3 -Illustration of the Code Coverage Obtained for 2G31-1 RWCUM-6-0-16 2G31-1 RWCUM-6-()..16 FLOW PIPE 50% COVERAGE OBTAINED DUE TO PIPE TO VALVE CONFIGURATION Figure 4 - Illustration of the Code Coverage Obtained for 2G31-1 RWCUM-6-0-17 2G31*1 RWCUM-6*Q*17 FLOW
~
PENE1'-RA-l-10-N~-~--:-.S:/ VALVE 50% COVERAGE OBTAINED DUE TO PI PE TO V/J.J..VE CONFIGURATlON ISI-RR-11 Version 1.0 Page 5 of 5