NL-17-058, Request IP2-ISI-RR-21 for Relief from Examinations of Code Class 2 Component Welds with Less than Essentially 100% Examination Coverage for Fourth Ten-Year Inservice Inspection Interval Closeout
| ML17191A921 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 05/30/2017 |
| From: | Vitale A J Entergy Nuclear Northeast |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| IP2-ISI-RR-21, NL-17-058 | |
| Download: ML17191A921 (12) | |
Text
- Entergy Nuclear Northeast Indian Point Energy Center
_____ _ --E t P.O. Box249 I n *n;r°" Buchanan, N.Y.1.0511-0249
- ** * -** * * . {71 t:!JJ Tel gf4 254 6700 May 30, 2017 NL-17-058 U.S. Nuclear Regulatory Commission
- ATTN: Document Control Desk* 11555 Rockville Pike, OWFN-2 F1 .
- Rockville, MD 20852-2738 Anthony J. Vitale Site Vice President
SUBJECT:
Request IP2-ISl-RR:*21 for Relief from Examinations of Code Class 2_ 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 th.e program plan; except that certain components could not fully 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 limitations.
Accordingly, pursuant to 1 OCFR 50.55a(g)(5)(iii), Entergy submits th.e attached IP2 Relief Request 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. J v NL-17-058 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 Attachment 1: Request IP2-ISl-RR-21 for Relief from Examinations of Code Class 2 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 8. Rhodes, President and CEO, NYSERDA Ms. Bridget Frymire, New York State Dept. of Public Service.:
ATTACHMENT 1 to NL-17-058 Request IP2-ISl-RR-21 for Relief from Examinations of Code Class 2 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-17-058 Attachment 1
Indian Point Unit No. 2 Fourth 10-year ISi Interval Relief Request No. IP2-ISl-RR-21 4th Interval Limited Examinations Proposed Alternative In Accordance with 10 CFR 50.55a(g)(5)(iii) lnservice Inspection Impracticality
- 1. ASME Code Component(s)
Affected Code Class: 2
References:
IWC-2500-1 Examination Category:
C-A, and C-F-1 Item Number: C1.10, C1 .20, and C5:21 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 IWC-2500 states in part, "Components shallbe examined and specified in Table IWC-2500-1." Table IWC-2500-1 requires an examination of applicable Class 2 pressure retaining-welds, which includes essentially 100% of weld length once during the ten-year interval for the following Code Categories:
Table 1 C-A C1.10 IWC-2500-1 Volumetric C-A C1.20 IWC-2500-1 Volumetric C-F-1 C5.21 IWC-2500-7 Volumetric
/Surface Code Case N-460 permits a reduction in examination coverage of Class 2 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 tJSNRC Regulatory Guide 1.147.
NL-17-058 Attachment 1 'flJl-. ------Pa-ge-Z-of'¢'
5 -
-4. Impracticality of Compliance The construction permit for IP2 was issued on October 14, 1966. At that time, the AS.ME 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. " . 1 OCFR50.55a recognizes the limitations to inservice inspection of components in accordance with Section XI of the ASME Code that are imposed due fo early plants design and construction, as follows: 10CFR50.55a(g)(1), "For a boiling or pressudzed water-cooled nuclear power facility 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 components (including supports) which are classified as ASME c*ode
- 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, 1 OCFR50.55a(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 NRG 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.
Table 2 C-A C1.10 RHXC 22-1 RHR 34.5 0.75 SS 66.5 RHR Heat Exchanger Shell Circumferential Weld C-A C1.20 RHXC 22-2 RHR 34.5 0.75 SS 81 RHR Heat Exchanger Head Circumferential Weld C-F-1 C5.21 56170 HIS 4 0.337 SS 50 Safety Injection Valve to Pipe Circumferential weld Note 1: For detailed information on each weld, see the writeup on the following pages.
NL-17-058 Attachment 1 ------Page-3-of.)l'5-
:--; C1.10 Residual Heat Removal Heat Exchanger Shell Circumferential Weld; RHXC 22-1 Tlie Residual Heat Removal (RHR) Heat Exchanger Shell circumferential weld RHXC 22-1 is 108.4" long and attaches the heat exchanger shell to a flange. Code coverage of the Code _ Required Volume (CRV) was only credited for those areas that were ultrasonically examined in accordance with the procedure requirements.
The ASME Section XI Code requirement is to examine essentially 100% of the weld. Due to the proximity of the heat exchanger flange to weld RHXC 22-1, the weld could not be scanned from the flange side. This physical limitation resulted in approximately 66.5%
- coverage, which is less than the required coverage of the CRV. I Weld RHXC 22-1 was inspected using 45 degree shear and 70 degree wave transducers, _0% pxial coverage from the flange side and 66% axial coverJ,ge on the shell side * (due to inlet /outlet nozzles) was obtained and 100% circumferential coverage was obtained on both sides. The weld is further limited by the inlet and outlet nozzle pads. The total -coverage for the entire weld was calculated as 66.5%. 1 See the Enclosure (Item A) for the cross-sectional view of the weld and a sketch of the limitations.
C1 .20 Residual Heat Removal Heat Exchanger Head Circumferential Weld; RHXC 22-2 -I The Residua,!
Heat Removal Heat Exchanger Head Circumferential Weld RHXC 22-2 is 108.3" long. Code coverage of the CRV was only credited *for those areas that were ultrasonically examined in with the procedure requirements.
The ASME Section XI Code Requirement is to examine essentially 100% of the weld. -The examination was limited in one direction on the heat exchanger shell side by the integrally welded component supports.
The total length of the limitation is 63.3" (31'.5" on one side and 31.8" on the other side). Due to the integrally welded supports which are used to support the Residual Heat Removal Heat Exchanger, the head to shell weld could-not be scanned from the supports side. This physical limitation resulted in approximately 81 % coverage, which is less than the required coverage of the CRV. See the Enclosure (Item B) for the cross-sectional view of the weld and a sketch of the
- limitations.
_________________________________
oockelNo.-51b241-----
C5.21 Safety Injection Circumferential Pipe Weld; 56 170 Attachment 1 f4 *-Page4off5 Weld 56 170 was ultrasonically examined using 45, 60 and 70 degree shear wave transducers, with *100% axial and circumferential coverage obtained from the pipe side of the weld. The weld is a valve to pipe weld and it is not possible to perform the ultrasonic from both s.ides of the weld since one side of the weld was not suitable for scanning due to the OD surface geometry of the component (Valve). Therefore, the weld only received a single sided examination resulting in less than 90% coverage of the required examination volume. This physical limitation resulted in approximately
!)0% coverage, which is less than the required coverage of the CRV. . . . The required surface exam was determined to be not needed by evaluation per Code Case N-663. . . See the Enclosure (Item C) for the .cross-sectional view of the weld and limitation.
- 5. Burden Caused By Compliance
-In order to inspect all of the required volume for these welds, the components wo.uld have to be redesigned to allow scanning from both sides of the weld, which is impractical.
There were no unacceptable indications found during the inspection of these welds. Based on the components designed configuration, the avail.able coverage will not meet the requirements of the ASME Code, or Code Case N-460. In accordance With 10 CFR 50.55a(g)(5)(iii), relief is requested for the components listea in Table 2 on the basis that the required 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 as 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 during system leakage tests on an inspection period frequency.
Those examinations were completed and no evidence of leakage was identified for these components.
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 ttie 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.
___ _ Attachment 1 121!-.
- -----* *---'. 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. IWC-2500, Table IWC-2500-1, Examination Category C-HSystem Leakage Tests with VT-2 visual examinations performed each inspection period 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 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 I WELD LIMITATION VIEWS AND DETAILS A. Residual Heat Removal Heat Exchanger Shell Circumferential Weld RHXC 22-1 --
_.;;:::..._
---=---
No Code Coverage Flange (downstream) e 45"S I Ii EJ<amination is singie-sidad and is further limiled by inlel & nu!lel na.l;Zlei reinforcfng paf,fs (10 "V'r arr from welds tQe, fora.* ei1ht1r side *ofIDC}.
Code Requfred i:;lllamination Volume= 158.70 sq/in. rt.ital Volume ofUmilatic:ts
= 53.36 sq/in. A:dal Scan UIS= 66% A'dal Scan b/S = 0% Circ Scan CW*= f 00% Cite.Scan CCW = 100% Toral Code Requierd Examination .Volume Coverage =66.5% Sketch l cf. 1 Shell (upstream)* uF Set.AN to .:Z:AIL£1/ocAT1...Jir
B. Residual Heat Removal Heat Exchanger Shell Circumferential Weld RHXC 22-2 ' -----*-------*------
---*-**-----*
R:HR Hut Exchangcir H'aad Circumferential Wold RHXC 2l-2 Sketch1 Ofl uescnpt!Qn OJ un111a111:1n:
The examin:aUon was UmUed fn one ctJrec:tJon on the heat exchanger she!I slde by lhe (titlegrally welded su11ports.
The to1at rengUa ar lhe llmllatlan Is ea.au (31.sa. on ona &tde aad 31.8" on the other stde). The tabll required examfninton area votume ts .113A sq1n. The trmUatton vorunt& Es 32.:91sqfn. (one d&ectlon, hnJf of the requlrad axamlnaUon volume). The to'IDI percent caveraga rs 81%. ....._ .....
.... . 1. ¥-** -*-**-'---*----.. *-*-* ........ . .. R\-IY.C zz. .. '"l:.,J-70°-5 mHz 600*5 mHz 45°-SmHz Pipe 700 -2;25 mHz-+ 5mHz eld Crown Width .5-H ---------------------------
C. Safety Injection Circumferential Pipe Weld 56170 -sa .. 110 Valve < Flow CRV Qbtained LK DN. CCW :§!f No Covera_ge Obtained Due To Config. LK UP. CW, CCW Sketch :tof l US *AX. CW,-CCW = 100% DS-AX. CW.-CCW = 0% --100,12 = 50%