NL-17-057, Request IP2-ISI-RR-20 for Relief from Examinations of Code Class 1 Component Welds with Less than Essentially 100% Examination Coverage for Fourth Ten-Year Inservice Inspection Interval Closeout
| ML17159A524 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 05/30/2017 |
| From: | Vitale A Entergy Nuclear Northeast |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-17-057 | |
| Download: ML17159A524 (28) | |
Text
Entergy Nuclear Northeast Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan , NY 1051 1-0249 Tel 914 254 6700 Anthony J . Vitale Site Vice President May 30, 2017 NL-17-057 U.S. Nuclear Regulatory Commission ATTN : Document Control Desk 11555 Rockville Pike, OWFN-2 F1 Rockville , MD 20852-2738
SUBJECT:
Request IP2-ISl-RR-20 for Relief from Examinations of Code Class 1 Component Welds with Less Than Essentially 100% Examination Coverage for Fourth Ten-Year lnservice Inspection Interval Closeout Indian Point Unit No. 2 Docket No. 50-247 License No . DPR-26
Dear Sir or Madam :
The Indian Point Unit No. 2 (IP2) Fourth Ten-Year inservice inspection interval ended on May 31 , 2016. During the Fourth interval , IP2 completed the required in-service examinations in accordance with the program plan , except that certain components could not ful ly meet the volumetric examination requirements stipulated in the ASME Section XI Code, 2001 Edition , 2003 Addenda , including the clarifications provided in the ASME Code Case N-460. Entergy Nuclear Operations, Inc. (Entergy) has determined that conformance with the Code requirement of essentially 100% coverage of weld volume or area examined was impractical due to various constraints and lim itations.
Accordingly, pursuant to 10CFR 50.55a (g)(5)(iii) , Entergy submits the attached IP2 Relief Request IP2-ISl-RR-20 for NRC review and approval. The relief request proposes alternatives where the requirement of "essentially 100%" volumetric examination was not feasible due to construction limitations, obstructions, accessibility and examination techniques." The alternatives and justifications are explained in the attachment which provides a list of components that require relief pursuant to 10 CFR 50.55a. The alternatives and justifications provide an acceptable level of quality and safety and will not adversely impact the health and safety of the public.
Entergy requests approval of the relief request by February 2018 to support the IP2 Refueling Outage 2R23.
NL-17-057 Docket No. 50-247 Page 2 of 2 Should you have any questions concerning this letter or require additional information ,
please contact Mr. Robert Walpole , Manager, Regulatory Assurance at (914) 254-6710.
Sincerely, AJV/gd : Request IP2-ISl-RR-20 for Relief from Examinations of Code Class 1 Component Welds with Less Than Essentially 100% Examination Coverage for Fourth Ten-Year lnservice Inspection Interval Closeout cc: Mr. Richard Guzman , Senior Project Manager, NRC NRR DORL Mr. Daniel H. Dorman, Regional Administrator, NRC Region 1 NRC Resident Inspector's Office Mr. John B. Rhodes, President and CEO, NYSERDA Ms. Bridget Frymire, New York State Dept. of Public Service
ATTACHMENT 1 to NL-17-057 Request IP2-ISl-RR-20 for Relief from Examinations of Code Class 1 Component Welds with Less Than Essentially 100% Examination Coverage for Fourth Ten-Year lnservice Inspection Interval Closeout ENTERGY NUCLEAR OPERATIONS, INC.
INDIAN POINT NUCLEAR GENERATING UNIT NO. 2 DOCKET NO. 50-247
NL-17-057 Docket No . 50-247 Attachment 1 Page 1 of 10 Indian Point Unit No. 2 Fourth 10-year ISi Interval Relief Request No. IP2-ISl-RR-20 4th Interval Limited Examinations Proposed Alternative In Accordance with 1 O CFR 50.SSa(g)(S)(iii) lnservice Inspection Impracticality
- 1. ASME Code Component(s) Affected Code Class: 1
References:
IW8-2500-1 Examination Categories: 8-A and R-A Item Numbers: 81 .11 , 81.21 , 81 .22, 81.40, R1 .11-3, R1 .16-1 , and R1.20-1
2. Applicable Code Edition and Addenda
The Code of Record for Indian Point Unit No. 2 (IP2) lnservice Inspection Fourth Ten-Year Interval is the ASME Section XI Code, 2001 Edition , 2003 Addenda .
- 3. Applicable Code Requirements ASME Section XI , Sub-article IW8-2500 states in part, "Components shall be examined and tested as specified in Table IW8-2500-1 ." Table IW8-2500-1 requires an examination of applicable Class 1 pressure retaining-welds , which includes essentially 100% of weld length once during the ten-year interval for the following Code Categories:
Table 1 ASME ASME Section XI Non Destructive Examination ASME Item Exam Requirements I Examination Category Number Figure Number (NOE) Method 8-A 81 .11 IW8-2500-1 Volumetric 8-A 81 .21 IW8-2500-3 Volumetric 8-A 81 .22 IW8-2500-3 Volumetric 8-A 81 .40 IW8-2500-5 Volumetric & Surface R-A R1 .11-3 IW8-2500-8 Volumetric R-A R1 .16-1 IW8-2500-8 Volumetric R-A R1 .20-1 IW8-2500-8 Volumetric
NL-17-057 Docket No. 50-247 Attachment 1 Page 2 of 10 A risk-informed in-service inspection (RI-ISi) program was approved for IP2 by the NRC via Relief Request RR-05 . The RI-ISi was developed for Class 1 piping welds for the Examination Category B-F , and B-J circumferential piping welds using the process described in EPRI TR-112657, in a manner consistent with ASME Code ,Section XI , Code Case N-578-1. Code Case N-578-1 examination requirements are listed in Table 1, Examination Category R-A, Item Nos.
R1 .11-3, R1 .16-1 , and R1 .20-1 , and require essentially 100 percent of the required volume of the weld and adjacent base material to be examined .
Code Case N-460 permits a reduction in examination coverage of Class 1 welds provided the coverage reduction is less than 10%. IP2 has adopted Code Case N-460 in the lnservice Inspection (ISi) Program Plan , as permitted by USNRC Regulatory Guide 1.147.
- 4. Impracticality of Compliance The construction permit for IP2 was issued on October 14, 1966. At that time , the ASME Boiler and Pressure Vessel Code covered fabrication of only nuclear vessels . Piping , pumps, and valves were built primarily to the rules of USAS 831 .1.0-1955, Power Piping . The IP2 systems and components were designed and fabricated before the examination requirements of ASME Section XI were formalized and published . Therefore, IP2 was not specifically designed to meet the requirements of ASME Section XI and full compliance is not feasible or practical within the limits of the current plant design .
10CFR50.55a recognizes the limitations to in-service inspection of components in accordance with Section XI of the ASME Code that are imposed due to early plants design and construction , as follows : 10CFR50.55a(g)(1 ), "For a boiling or pressurized water-cooled nuclear power faci lity whose construction permit was issued before January 1, 1971 , components (including supports) must meet the requirements of paragraphs (g)(4) and (g)(5) of this section to the extent practical. "
10CFR50.55a(g)(4) states, "Throughout the service life of a boiling or pressurized water-cooled nuclear power facility, components (including supports) which are classified as ASME Code Class 1, Class 2, and Class 3 must meet the requirements , except design and access provisions and preservice examination requirements , set forth in Section XI of editions and addenda of the ASME BPV Code ... to the extent practical within the limitations of design, geometry and materials of construction of the components ."
Further, 10CFR50.55a(g)(5)(iii) states that , "If the licensee has determined that conformance with a Code requirement is impractical for its facility, the licensee must notify the NRC and submit, as specified in § 50.4, information to support the determinations."
IP2 has determined that the following welds were limited from achieving greater than 90% of the required examination volume for in-service examinations due to component configuration or physical barriers which would require a major modification to the existing hardware.
NL-17-057 Docket No. 50-247 Attachment 1 Page 3 of 10 Table 2 Coverage Component Dia Thk Cat Item System Mat % Description ID (in) (in)
(Note 1)
RV Lower Shell Head B-A B1 .11 RPVC4 RCS 1731D 5.31 cs 79.5 Circumferential Weld 86 RV Upper Head B-A B1 .21 RVHC1 RCS Radius 7.0 cs N/A Circumferential Weld 88 .16 RV Lower Head B-A B1 .21 RPVC5 RCS Radius 5.31 cs 69.97 Circumferential Weld 88 .16 B-A B1.22 RPVM2 RCS Radius 5.31 cs 72.56 Bottom Head RV MW @90 88.16 B-A B1 .22 RPVM4 RCS Radius 5.31 cs 81 .92 Bottom Head RV MW @330 86 RV Upper Head-to-Flange B-A B1.40 RVHC2 RCS Radius 7.0 cs 85.7 Weld Circumferential weld Valve-R-A R1 .11-3 351 4 SIS 10 1.0 SS 50 to-Pipe Degradation Mechanism: TASCS , IGSCC Circumferential weld- Valve-R-A R1 .11-3 353 4 SIS 10 1.0 SS 50 to-Pipe Degradation Mechanism : TASCS , IGSCC Circumferential weld . Sweep-R-A R1 .16-1 351 2 SIS 10 1.0 SS 70 o-let-to-Pipe Degradation Mechanism : IGSCC Circumferential weld . Branch Connection to Pipe.
R-A R1 .16-1 353 1 SIS 10 2.325 SS 50 Degradation Mechanism :
IGSCC Circumferential weld R1 .20- Rl@247. Safe end to elbow.
R-A RCC21 -14 RCS 27.5 ID 2.5 SS 42.89 1(Note2) Degradation Mechanism:
NONE Circumferential weld R1 .20- Rl@113 . Safe end to elbow.
R-A RCC22-1 4 RCS 27.5 ID 2.5 SS 42.89 1(Note2) Degradation Mechanism:
NONE Circumferential weld R1 .20- Rl@293 . Safe end to elbow.
R-A RCC23-14 RCS 27.5 ID 2.5 SS 42.89 1(Note2) Degradation Mechanism :
NONE Circumferential weld R1 .20- Rl@067 . Safe end to elbow.
R-A RCC24-1 4 RCS 27.5 ID 2.5 SS 42.89 1(Note2) Degradation Mechanism :
NONE Table Notes are on the next page
NL-17-057 Docket No. 50-247 Attachment 1 Page 4of10 Table Notes:
Note 1: For detailed information on each weld , see the writeup on the following pages.
Note 2: Indian Point Unit No. 2 received NRC approval on March 19, 2004 (TAC No. MC0624) to implement a risk-informed inspection program for Class 1 Category B-F and B-J piping welds based on the methodology detailed in EPRI Topical Report TR-112657, Revision B-A, and Code Case N-578 as an alternative to the requirements of the 1989 edition ASME XI code , No addenda . The risk-informed methodology used at IP2 includes all category B-F and B-J welds in the determination of the final risk-informed inspection sample of 61 Class 1 welds. In 2006, Class 1 circumferential piping welds were assigned alternate examination category and Code item numbers that were consistent with ASME Section XI Code Case N-578-1. The numbering system established in Code Case N-578-1 is similar to the one used in Code Case N-578. However, the Code Case N-578-1 numbering system is more complete and more accurately reflects the technical criteria established in EPRI Topical Report No. TR-1 12657. For these reasons , the numbering system established in Code Case N-578-1 was used instead of the one shown in Code Case N-578 ; and was carried forward into the fourth interval.
Abbreviations :
RCS - Reactor Coolant System TASCS - Thermal Stratification , Cycling , and Striping SIS - Safety Injection System IGSCC - lntergranular Stress Corrosion Cracking 81 .11 RV Lower Shell to Head Circumferential weld ; RPVC4 The Lower Shell to Head Circumferential weld (RPVC4) examination was conducted from the vessel inside diameter (ID) and performed using 45° dual element and single element L-wave transducers for volumes of metal from the clad base-metal interface to a depth of 0.6 "t" and 45° shear wave transducers for depths from 0.6 "t" to the outside diameter (OD) surface.
Scanning was conducted perpendicular to and parallel to the exam volume at speeds less than or equal to 5.5 inches per second . Four-directional interrogation of the examination volume was performed wherever possible.
The Lower Shell to Head Circumferential weld is limited in examination coverage due to the proximity of 6 core support lugs. Scanning was conducted between and below the obstructing lugs with the scan boundaries maximized by visually assisted positioning of the exam head.
Coverage was achieved to the maximum extent practical by using solid modeling to design the robot scan routines around the limitations. Extra transducers were also added to the exam sled to maximize coverage . Final examination coverage is estimated at 79.5% .
See the Enclosure (Item A) for the cross-sectional view of the weld and a sketch of the limitations.
NL-17-057 Docket No. 50-247 Attachment 1 Page 5of10 81 .21 RV Upper Head Circumferential Weld ; RVHC1 and Lower Head Circumferential Weld ;
RPVC5 RVHC1 The closure head peel segment to disc circumferential weld (RVHC1) is completely enclosed within the pattern of Control Rod Drive Mechanism penetrations inside the shroud and , as such is completely inaccessible for volumetric examination as would be required by Sub-article IWB-2500. This weld was not able to be examined. Refer to the Enclosure (Item B) drawing for weld location on the closure head.
RPVC5 The Lower Head Circumferential weld (RPVC5) examination was conducted from the vessel ID using 45° dual element and single element L-wave transducers for volumes of metal from the clad base-metal interface to a depth of 0.6 "t" and 45° shear wave transducers for depths from 0.6 "t" to the OD surface. Scanning was conducted perpendicular to and parallel to the exam volume of the weld at speeds less than or equal to 5.5 inches per second. Four-directional interrogation of the examination volume was performed wherever possible.
The Lower Head Circumferential weld is limited in examination coverage due to the proximity of multiple BMI nozzles. Required scanning was conducted as close as possible to the obstructing BMls with the scan boundaries maximized by visually assisted positioning of the exam head .
Coverage was achieved to the maximum extent practical by using solid modeling to design the robot scan routines around the limitations. Extra transducers were also added to the exam sled to maximize coverage . Final examination coverage is estimated at 69.97% .
See the Enclosure (Item C) for the cross-sectional view of the weld and a sketch of the limitations.
81 .22 Bottom Head RV Meridional Welds RPVM2 @90° and RPVM4@330° RPVM2 @90° The Lower Head Meridional weld @90° (RPVM2) is limited in examination coverage due to the proximity of BMI nozzle #44 which is located at approximately the weld centerline . Required scanning was conducted as close as possible to the obstructing BMI with the scan boundaries maximized by visually assisted positioning of the exam head . Coverage was achieved to the maximum extent practical by using solid modeling to design the robot scan routines around the limitation . Extra transducers were also added to the exam sled to maximize coverage. Final examination coverage is estimated at 72 .56% .
See the Enclosure (Item D) for the cross-sectional view of the weld and a sketch of the limitations.
NL-17-057 Docket No. 50-247 Attachment 1 Page 6of10 RPVM4@330° The Lower Head Meridional weld @ 330° is limited in examination coverage due to the proximity of BMI nozzle #49 . Required scanning was conducted as close as possible to the obstructing BMI with the scan boundaries maximized by visually assisted positioning of the exam head. Coverage was achieved to the maximum extent practical by using solid modeling to design the robot scan routines around the limitation . Extra transducers were also added to the exam sled to maximize coverage. Final examination coverage is estimated at 81.92%.
See the Enclosure (Item E) for the cross-sectional view of the weld and a sketch of the limitations.
81 .40 Reactor Vessel (RV) Upper Head-to-Flange Weld; RVHC2 The Reactor Vessel (RV) Upper Head-to-Flange Weld has limited accessibility due to contour of the flange weld . These limitations resulted in approximately 85 .7% coverage by ultrasonic examination , which is less than the coverage required volume . Code coverage of the Code-required volume was only credited for those areas that were examined in accordance with the qualified procedure. The ASME Section XI Code requirement is to examine essentially 100% of the weld.
From those sketches with the ultrasonic beam angles included , it can be seen that the ultrasonic beam cannot "reach " any further down into the component because of the sharp transition of the head to flanged surface.
Weld RVHC2 was inspected using 45 and 60 degree shear wave transducers . This weld was scanned in four directions to the extent possible. The surface examination conducted confirmed acceptable results with no recordable indications.
See the Enclosure (Item F) for the cross-sectional view of the weld and a sketch of the limitations.
R1 .11-3 Risk Informed Piping Welds 351 4. 353 4 The ultrasonic examination of these pipe welds was limited in coverage due to component configuration . It is not possible to perform the ultrasonic examination from both sides of the weld since one side of the weld was not suitable for scanning due to the OD surface geometry of the component (pipe to valve weld) . Therefore , the welds only received a single sided examination or partial single sided examination resulting in less than 90% coverage of the required examination volume . The percentage of coverage reported represents the aggregate coverage from all examination angles and scans performed on the weld and adjacent base material.
NL-17-057 Docket No. 50-247 Attachment 1 Page 7 of 10 Welds 351 4 and 353 4 are valve to pipe welds with no inspection able to be performed from the valve side due to component geometry. This physical limitation resulted in approximately 50% coverage , which is less than the required coverage .
Weld 351 4 was inspected using 45 and 60 degree shear and 70 degree longitudinal wave transducers . 100% axial and circumferential coverage was obtained from the pipe side of the weld for the 45 degree, 60 degree and 70 degree. There was no coverage obtained from the valve side of the weld . The total coverage for the entire weld was calculated as 50% .
Weld 353 4 was inspected using 45 and 60 degree shear and 70 degree longitudinal wave transducers . 100% axial and circumferential coverage was obtained from the pipe side of the weld for the 45 degree, 60 degree and 70 degree. There was no coverage obtained from the valve side of the weld . The total coverage for the entire weld was calculated as 50% .
See the Enclosure (Item G) for the cross-sectional view of the welds and limitations.
R1 .16-1 Risk Informed Piping Welds 351 2 and 353 1 The ultrasonic examination of these pipe welds was limited in coverage due to component configuration. It is not possible to perform the ultrasonic examination from both sides of the weld since one side of the weld was not suitable for complete scanning due to the OD surface geometry of the component. It is not possible to perform the complete ultrasonic examination of weld 351 2 elbow to the sweep-o-let due to the OD surface geometry of the component. Weld 351 2 is a branch connection sweep-o-let to pipe weld with no inspection able to be performed from the sweep-o-let side due to component geometry. This physical limitation resulted in approximately 70% coverage , which is less than the required examination coverage volume .
Weld 351 2 was inspected using 45 degree shear and 60 degree longitudinal wave transducers.
100% coverage was obtained for both the axial and circumferential scans from the elbow side of the weld . Complete scanning was not possible on the sweep-o-let side due to the radius of the fitting . Partial coverage was obtained on the scans from the sweep-o-let side. The total coverage for the entire weld was calculated as 70% .
Weld 353 1 is a branch connection to pipe weld with no inspection able to be performed from the branch connection side due to component geometry. This physical limitation resulted in approximately 50% coverage, which is less than the required coverage .
Weld 353 1 was inspected using 45 and 60 degree shear and 60 degree longitudinal wave transducers. 100% axial and circumferential coverage was obtained from the pipe side of the weld for both the 45 degree and 60 degree scans. There was no coverage obtained from the branch side of the weld . The total coverage for the entire weld was calculated as 50% .
See the Enclosure (Item H) for the cross-sectional view of the welds and limitations.
NL-17-057 Docket No. 50-247 Attachment 1 Page 8of10 R1 .20-1 Risk Informed Piping Weld RCC21-14 , RCC22-14 , RCC23-14 , RCC24-14 On the Reactor Vessel Inlet nozzles, a cast stainless steel (A351 Grade CF8M) elbow is welded to the safe-end upstream of the dissimilar metal weld (welds RCC24-14, RCC22-14 , RCC21-14, RCC23 *14). Since ASME Section XI , Appendix VIII , Supplement 9 for Cast Austenitic Piping Welds is in the course of preparation there are currently no Appendix VIII Performance Demonstration Initiative (POI) qualified procedures to inspect cast stainless steel materials. The entire volume was examined employing the Appendix VIII procedure qualified for the examination of austenitic welds .
These welds were examined from the nozzle ID with 70 degree transducers. Scanning was performed both parallel and perpendicular to each weld. The scan index increment was 0.25" for axial scans and 0.08" for circumferential scans. The safe-end to elbow welds were examined from the cast elbow side with a procedure and personnel qualified to Appendix VIII Supplement 2 (austenitic) and Supplement 10 (dissimilar metal) in the absence of Code-prescribed technique qualification criteria . Additionally, eddy current technique was used to supplement the examination at the ID surface finding no indication .
Code-required examination volume that was scanned is estimated at greater than 98% . This documents the Code-required examination volume that was scanned utilizing both a POI qualified technique , and the use of the POI qualified procedure for areas where there are no POI qualified procedures (i.e. the cast elbows) . This coverage calculation considers all four required examination beam directions and shows that greater than 98% of the Code-required examination volume was scanned on all 4 welds . The only limitations to scanning were due to ID surface condition configurations .
Weld- RCC24 99.45% examined Weld- RCC22 99 .82% exam ined Weld- RCC21 98.36% examined Weld- RCC23 98.89% examined Calculation of limitations to circumferential scanning due to ID surface configurations were performed automatically in Paragon analysis software by use of the ultrasonically obtained ID profiles.
When disallowing examination into or from the cast material , coverage of the Code-required volume is estimated at 42.89%. As can be seen from the Enclosure, the limited coverage area includes any area which requires the sound to pass thru the cast stainless steel material. In the case of the axial scan from the cast side shown in the Enclosure, this means no coverage is credited until the sound path travels from the transducer, through the clad , directly into the weld , and then into the base metal of the safe-end . The same logic is applied for the axial scan from the safe end side and the circumferential scans.
See the Enclosure (Item I) for the cross-sectional view of the welds and limitations.
NL-17-057 Docket No. 50-247 Attachment 1 Page 9 of 10
- 5. Burden Caused By Compliance Compliance with the examination coverage requirements of ASME Section XI would require extensive engineering , modification, redesign, or replacement of components where geometry is inherent to the component design .
In order to scan all of the required volume for these welds , the components would have to be redesigned to allow scanning from both sides of the weld, which is impractical. There were no unacceptable indications (other than geometric indications) found during the inspection of these welds . Based on the components designed configuration, the available coverage will not meet the requirements of the ASME Code, Code Case N-578-1 or Code Case N-460.
In accordance with 10 CFR 50.55a(g)(5)(iii), relief is requested for the components listed in Table 2 on the basis that the required examination coverage of "essentially 100 percent" is impractical due to physical obstructions and the limitations imposed by design, geometry, and materials of construction . IP2 utilized examination techniques required in 10 CFR 50.55a(g)(6)(ii)(C), that achieved the maximum practical amount of coverage obtainable within the limitations imposed by the design of the components and examination techniques .
Additionally, VT-2 examinations are performed on the subject components of the Reactor Coolant Pressure Boundary during system leakage tests on a refueling outage frequency.
Those examinations were completed each refueling outage and no evidence of leakage was identified for these components.
Further, the mandated requirement in 10 CFR 50.55a(b)(2)(xv)(A)(2), which states, "Where examination from both sides is not possible on austenitic welds or dissimilar metal welds, full coverage credit from a single side may be claimed only after completing a successful single-sided Appendix VIII demonstration using flaws on the opposite side of the weld" . The Appendix VIII techniques applied at IP2 are not qualified for "Detection or length sizing of circumferentially oriented flaw indications when only single side access is available and the flaw is located on the far side of the weld ."
Based on the design configuration of the components and available examinations techniques ,
IP2 was not able to achieve greater than 90% Code coverage of the required examination volume for the components listed above without major modifications to the components.
- 6. Proposed Alternative and Basis for Use No alternative examinations were performed for the welds during the completed inspection interval. The use of radiography as an alternate volumetric examination for all the above listed components is not practical due to component thickness and/or geometric configurations , or the system being water filled resulting in the inability to achieve the code-required radiographic sensitivity. Other restrictions making radiography impractical are the physical barriers prohibiting access for placement of the source and film .
NL-17-057 Docket No. 50-247 Attachment 1 Page 10 of 10 Based on the above, with due consideration of the earlier plant design , the underlying objectives of the Code-required examinations have been met. The examinations were completed to the extent practical and evidenced no unacceptable flaws present. IWB-2500, Table IWB-2500-1, Examination Category B-P System Leakage Tests with VT-2 visual examinations performed each refueling outage provide adequate assurance of pressure boundary integrity. In addition to the above Code-required examinations , there are other activities which provide a high level of confidence that, in the unlikely event that leakage did occur through these welds , it would be detected and proper action taken. Specifically, system leak rate limitations imposed by Technical Specifications as well as containment building normal sump rate monitoring , provide additional assurance that any leakage would be detected prior to gross failure of the component. The component welds were inspected by volumetric and surface NOE methods during construction and verified to be free from unacceptable fabrication defects. Therefore , reasonable assurance of quality and safety has been demonstrated .
- 7. Duration of Proposed Alternative Relief is requested for the Fourth Ten-year Interval of the lnservice Inspection Program for IP2 which was effective from March 1, 2007, through May 31 , 2016.
- 8. Enclosure Indian Point Unit No. 2 Fourth Ten-year Interval ISi program datasheets for examinations with less than "Essentially 100%" coverage are provided in the Enclosure titled "Weld Limitation Views and Details."
ENCLOSURE WELD LIMITATION VIEWS AND DETAILS
A. Reactor Vessel (RV) Lower Shell to Head Circumferential Weld RPVC4 Lo..ver Shell lo Head Circ.. Weld ( RPVC4) Sketch 1 of 2 The Lower Shell to Head Circ \.'Jeld is limited in examination coverage due to the proximity of 6 core support lugs. Scanning was conducted between and below the obstructing lugs with the scan boundaries maximized by v lsl'ally assisted positioning of the exam head. Coverage was achieved to tile maximum extent practical by using sotld modeling to design the robot scan routines around the limitations. Extra transducers were also added o the exam sled to maximize coverage. Fnal examination coverage is estlmaled at 79.5%.
RPVC+ PERPENDICULAR SCAN COV£P-AGE NOTE - the values depicted on this sketch are in approimate degree, coverage calcualtions are based on sol id modelin~
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C. Reactor Vessel (RV) Lower Head Circumferential weld RPVCS Low Head Ckc, Wlfd IBP\ICS) Sketch 1of2 The Lower He8d Circ. Weld la limited in examination cownige due to the pra>dmlly ot multiple BMI U>es, ScaMlng waa conducted betWeen, below and above tie BMI tubes with._ ecan ~ mutmlzed by visually asallt8d poUloning ot the eam had.
Cownlg* - ec:hleved to the maximum extent practical by Uling 90lld modeling to de9lgr\ the robot scan routin* *round the limlllng BMI tubes. EJdra transduc:ef'a were elso 9dded to lhe mm sled to maximize CCMnlge. Anll examination coven19e Is estimated
- 69.97%.
RPVCS PERPENDICULAR SCAN COVERAGE PERP SCANS FU.. L COVERAGE = 218.09*
P£RP SCANS PARTIAL COVERAGE = 41.04* Clncludn welgtitlng For- l!Nted sco.ns)
PERP SCANS NC COVERAGE IPERP SCAN aJVERAGE
- 218.09* + *41.04*J36C)* e 71.98Zf
- I ,, "
- A 190*
- ' J J!J .p JI' PERP SCAN COVERAGE = 7198Z PARALLEL SCAN COVERAGE = 67.96Z 139.94:1. I 2 = 69.97Z
C. Reactor Vessel (RV) Lower Head Circumferential weld RPVCS Lpwer HR! Circ.. Weld CROOS)
Sketd12 of 2 The Lawer Head Clrc.. Weld Is limtted In examination coverage due f9 the prc>>dmtty of multipl'e BMI tubes. Scanning WIS conducted between, below and' above the BMI tubes wilh 1ht scan boundarlel maxlmlmd by vl&uaDy all8istad positioning of the 8lOlm head.
Collenlge was achieved to the maximum extent practical bv using IOlid modeling to desfgn the tobot sc:an routinn around the llmiting BMC tubes. Extra transducers were also added to the exam sled to mufmlm CIJ\/8nlge.. Final examination covenage 1$
estimated at 69.97%.
RPVCS PARALLEL SCAN COVERAGE
- PARALLEL SCANS. FULL COVERAGE ::. 16Ll7"
~PARALLE L SCANS PARTIAL COVERAGE: ::. 83,47* (Includes WE'lght!ng fo.r llrited sc:cn c=JPARALLEL SCAN*S NO COVERAGE PARALLEL SCAN COVERAGE = 161.17* + 93.47*/360* = 67.96Y.
.p
~,p Ill J' "'
I~
"'
- 1ao*
.; JJ JI' p J
,,. PERP SCAN COVERAGE = 7J.98Z.
PARALLEL SCAN COVERAGE ::: 67.967.
t39.94Y. I 2 .. 69.971.
D. Reactor Vessel (RV) Bottom Head RV Meridional Welds RPVM2 @90 Bottom H ~ Meridional W e!'J 90"CRPVM21 Sketch 1of 1 The Bo'.tom Head Meridion Weld 90* is I m1ted in examinallon <X>Verago due to the loc:ittion of BMI tube #44 at the wold cent ino. Scanning was conducted above e,M M>o #4C wi1h the scan boundaries maximiicd by visually assisted pOS:lioll. g o( the exam head. COYarago was achieved to Ulo m x:imum extent practical by usin g solid TOTAL VELD AREA = 370.49 SQIN modcl'ng to design the robo scan routines around lhC limitiog BMI lube. Extra 1t1111odu were also addod to th eimm led to mmdmize coverag . inal xaminabon coverage is estimated al 72.56%.
PARALL EL SCAN COVERAGE = 250.78 QIN I 370 .49 SQ IN = 7.69 %
PtRP SCAN COV ERAGE = 286.83 SQlN I 370.49 SQI N = 77.42/.
PARALLEL SCAN PERP NDICULAR SCAN 6 I 69 /.
- 77. 42/.
145. 11/. I 2 = 72.56/.
34 7.69 (75.<. 2 ' ) 341 .(,9 <75.42")
f\ i!. 3 H\J 4 TOP PERP TOP PrRP TOP PARALLEL TOP Pf\R LLCL
~ ULL COVERAGE
.... NO COVERAGE 3%.13 <36.76 ' )
BOTTOM PC:R BOTTOH PARALL L
E. Reactor Vessel (RV) Lower Head Meridional Weld RPVM4 @330°
§ottom He d rid ioQ1! Weld@ 330* CRPV Ml Sketch 1 of 1 The Do cm Head lr1er1dlonal Weld 330* Is limited in ~inatlon o::N rage duo to th proximity of B 11 tu #49 to Id centerline. Scan Ing .. conduct round BMI lube
- 49 with th n boondarics maxim' by vi uallJ" a led positioning of lhe cxnm hond. Cov rag was ach eved lo the maximum nt practical by uslng sofid modeling TOTAL J L D /\REA = 370.49 QI N lo d ig n the robot scan rou nes around th limiting BMI tu Extra transducers were aloo oddod lo Iha :cam sled to maidmi c:overage . Flnal minati on ge Is esUmalcd ot 8 t .02.'r..
PA f< /\LL EL SCAN CO VERAGE = 30 .62 SQIN I 37 0.4 9 SQIN = 81.1 4/.
PCRP CAN COVlRAGE = 306.4 SQ I 3 70.49 SQI N "" 82.7/.
P/\RA L L EL C AN P R C DI CUL AR SCAN 81.141.
82.7%
16 ~ . 8 '1 % I 2 -* 81.92%
J 47.G9 <75.4 c * > 34 7.6 <7 3.4 2*>
TOP PERP TOP P E P TOP PA /\LL L TO PARA l Fl
~ FULL COVERAGE 111111 PARTIAL COVERAGE
F. Reactor Vessel (RV) Upper Head-to-Flange Weld RVHC2 5 K£TC fl I of' l RV HC 2.. HfAD 1o FLfVOtf:ie e.11
'f. t,O 7./,/, 7.7'1
£ I
.I c - i. e" CR V Ol3TRINED oc. - 100 % /Cc ~
Cv..> l..j ,..:.- 88 % I ,, c. w/c..c.vJ
<- c:.....> Lf5"- 88 'Yo I 8-"- L k.. UP* ll-sj(;IJ*
l-K ~ '15°- l.S %
l i< p 0
loo /u 45'!- :5o ~~ -+--+--T- .3 8 ro - 1 I 12 . ()o/o
-'=---=--=~---!
,,_ _..._-+_
1~037 l.6- 1 CW (J,0 °- 88% \lot. :5s£J> - I
~w r.o - 88% 75°'.Cot PE.R B '~ I L I:. .l:>IJ f.;:f - J 00 % HEAD L0o ' ,-c,
.ho..>.,>
I l 1:.. lAP bf): ~ . S% I
- - 7. f '!_ t - - -- -
-- 8.t,,"_ - -
--- - - - -- - f. s '-'- -
G. Risk Informed Piping Welds 351 4 and 353 4 Risk Inf ormed Piping We ld 351 4 Sketch 1of1 Weld #351-4 Weld l ength =34.0" Valve 897A Flow ) Pipe
- -' /-*,.. - . l
) * -*
I:'"
- ~
45° 60 70°L 45°
- -J) I - - - --J- _
~- /
/
/
50% CRV Obtained OS Only Co rage Calculation:
Ci rcum erentiaf cw Scan 50 Circumferent ial CCW Scan 50%
Axial Dow stream Sca n 0 Axial Upstr am Scan 100%
To tal Estim ted co erage 200/4=...Q.:_
G. Risk Informed Piping Welds 351 4 and 353 4 Risk Informed Piping Weld 353 4 Se ch lof l Weld #353-4 Weld Length =34.0" Valve 897C Flow Pipe
)
45° 60° 700L
_______450)_ /'
/
~1.0
~
1.063" CRV Obtained OS Only 50%
1.064" 50%
Cjrcumfere-nt ial CCW Sca n 50" Axial Dow st ream Scan 0%
Axi al Upstr e:irn Sr:a 100%
Tnral F'itimat fld C"nv ralle ]00 ( 4 _ 0%
H. Risk Informed Piping Welds 351 2 and 353 1 llsk lnformtcl Plpi,. Wild 151 2 SUtct, 1011 Drawing not to1C111 Elbow Inside Rad ius Sweep-olet Elbow Inside Rldlus mltatlon U .O'" J: l .'5" x 0.4" .., L'4 sq/ln Elbow Outside Radius l..lmitllion 1U" x 0.55" lli 0.4" = +}.ll sq/in lot.ti *
- a n 12.16 sq~
Total Examination Volume= 40.50 sq/in To al Limitation = 12.15 sq/in Total Coverage Credited =28.35 sq/in or 70%
H. Risk Informed Piping Welds 351 2 and 353 1 Risk Inform d Plpin1We ld353 l Sketch lo 1 We ld #353~ 1 W Id nglh =44 .0" Weld Crown Width =3 O" Cold Leg Flow Branch Connection
\ 2.721" < 2.4 " 2.476"
\
2.415" 4SoS 600IRL
\
\
~
1" I 50%
so Aici I Downs ram Sc n o Axi;;tl Upstr~am Sea + 100%
Tor If-; ima ed Covera~e 200 / 4 ,. 50%
I. Risk Informed Piping Weld RCC21-14, RCC22-14, RCC23-14, RCC24-14 ru Risk Informed Piping Welds RCC21*14, RCC22*14, RCC23*14, RCC24-14 cu i--
CA ' I - 1 30 \ I J;(
c.-s rt*ao I
I T
- DO
.I I< l ),)'°) '
SC:TJU.~ XI ( XAH VCk..UM!: SECT! XI EXAM VOLUH!:
11.1 .:.:: (X ... ~I -o C.J
- i. -
- I
/.Li
-F /P ~n::- *~r __ ll L:::- @ ...., 7. Q
~
c ,,-,, ..' -
r, -- ;
.. 'I r-r ~ I~ 3° -~c :::>c: - l I r- ,..
3W 2 1i 7 .. _-""-*
/ I :1.. l r G ~~,.
. ...;) . '**
-r;:) ~
.,)
I 75 '?
Coverage Calculation :
S£ CTIOll XI EXAM VOLUME Circumf rential CW Scan 49.22%
LIMlfE!l (OV(i!Afif* /.X l ."ll 'C:AUS r Ru-. Ml ( !, !) 'Wt Circumferential CCW Scan 49.22%
61£. ~ f U'll :E: !l Axial Downstream Scan 11.46%
Axial Upstream Scan + 61.66%
Note - Flow is from the Cast Elbow Side of the Total Estimated Coverage 171.56/4 = 42 .89%
weld toward the weld for each sketch above