View source for CNRO-2015-00002, Entergy Operations, Inc. - Response to RAI Questions and Submittal of RR EN-15-2, Rev. 1

{{Adams
| number = ML16005A172
| issue date = 12/04/2015
| title = Entergy Operations, Inc. - Response to RAI Questions and Submittal of RR EN-15-2, Rev. 1
| author name = Ford B
| author affiliation = Entergy Nuclear Operations, Inc, Entergy Operations, Inc
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000247, 05000255, 05000286, 05000293, 05000313, 05000333, 05000368, 05000382, 05000416, 05000458
| license number = DFR-059, DPR-020, DPR-026, DPR-035, DPR-051, DPR-064, NPF-006, NPF-029, NPF-038, NPF-047
| contact person = 
| case reference number = CAC MF6654, CAC MF6655, CAC MF6656, CAC MF6657, CAC MF6658, CAC MF6659, CAC MF6660, CAC MF6661, CAC MF6662, CAC MF6663, CNRO-2015-000025
| document type = Letter type:CNRO, Response to Request for Additional Information (RAI)
| page count = 27
| project = CAC:MF6654, CAC:MF6655, CAC:MF6656, CAC:MF6657, CAC:MF6658, CAC:MF6659, CAC:MF6660, CAC:MF6661, CAC:MF6662, CAC:MF6663
| stage = Response to RAI
}}

=Text=
{{#Wiki_filter:Entergy Operations, Inc.
Entergy Nuclear Operations, Inc.
1340 Echelon Parkway Jackson, MS  39213 Bryan S. Ford Senior Manager, Fleet Regulatory Assurance (601) 368-5516 bford@entergy.com CNRO-2015-0000 25 December 4, 2015  U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
-0001  

==SUBJECT:==
Response to RAI Questions and Submittal of RR EN 2, Rev. 1   Relief Request Number RR EN 2, Rev. 1 - Proposed Alternative to Use ASME Code Case N
-786-1, "Alternative Requirements for Sleeve Reinforcement of Class 2 and 3 Moderate
-Energy Carbon Steel Piping, Section XI, Division 1"   Arkansas Nuclear One, Units 1 & 2 Docket Nos. 50
-313 & 50-368 License Nos. DPR
-51 & NPF-6  Palisades Nuclear Plant Docket 50-255 License No. DPR
-20  Grand Gulf Nuclear Station, Unit 1 Docket No. 50
-416 License No. NPF
-29  Pilgrim Nuclear Power Station Docket No. 50
-293 License No. DPR
-35  James A. Fitzpatrick Nuclear Power Plant Docket No.
50-333 License No. DFR
-59  River Bend Station, Unit 1 Docket No. 50
-458 License No. NPF
-47  Indian Point Energy Center, Units 2 & 3 Docket Nos. 50
-247 & 50-2 8 6 License Nos. DPR
-26 & DPR-64  Waterford 3 Steam Electric Station Docket No. 50
-382 License No. NPF-38  

==REFERENCES:==
: 1. Entergy letter to the NRC, Regarding Relief Request Number RR EN 2 - Proposed Alternative to Use ASME Code Case N
-786-1, "Alternative Requirements for Sleeve Reinforcement of Class 2 and 3 Moderate-Energy Carbon Steel Piping, Section XI, Division 1", dated August 20, 2015
: 2. E-mail from Ms. Booma Venkataraman, NRC Project Manager, to Mr. Guy Davant, Entergy, "REQUEST FOR ADDITIONAL INFORMATION: Relief Request RR EN 2 Proposed Alternative to Use ASME Code Case N-786-1 to repair degraded piping for Arkansas Nuclear One et al (CAC MF6654 to MF6663)," dated November 6, 2015

==Dear Sir or Madam:==

Pursuant to 10 CFR 50.55a(z)(2) and via Reference 1, Entergy Operations, Inc. and Entergy Nuclear Operations, Inc. (hereafter referred to collectively as "Entergy") submitted a relief CNRO-2015-000 25 Page 2 of 3  request for NRC approval to use Code Case N
-786-1 as an alternative to the ASME Boiler and Pressure Vessel Code, Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," requirements on the basis that the current code requirements result in hardship and/or unusual difficulty. Specifically, this request is for application of ASME Boiler and Pressure Vessel Code, Code Case N
-786-1 for Class 2 and Class 3 moderate energy piping system repairs resulting from degradation mechanisms such as localized erosion, corrosion, cavitation
, and pitting at the Entergy nuclear plants listed above.
The NRC subsequently transmitted to Entergy via Reference 2 a Request for Additional Information (RAI) and request ed Entergy provide responses by December 7, 2015.
Attachment 1 to this letter provides the specific response s to each RAI question.
Certain responses required minor revision or added information to the subject relief request. As such, Entergy hereby submits Revision 1 to RR EN 2 , which incorporated the necessary changes. RR EN 2, Rev. 1, which is provided in Attachment 2, supersedes the previous submitted Rev. 0 in its entirety.
Changes are shown by revision bars in the right margins.
The information provided in the attachment s demonstrate s that the proposed request provides an acceptable level of quality and safety and that compliance with the specified requirements of ASME Section XI would result in a hardship and/or unusual difficulty without a compensating increase in the level of quality and safety.
This relief request is proposed for the 10
-year Inservice Inspection (ISI) intervals for the facilities as identified in Section 2 of the attached relief request.
Since this relief request could be needed at any time to address an emergent condition, Entergy requests NRC approval as soon as possible or by August 18, 2016. This letter contains no new commitments.
If you have any questions, please contact Mr. Guy Davant at (601) 368
-5756. Sincerely, BSF/ghd/aye Attachment s: 1. Response to NRC RAI Regarding Relief Request RR
-EN-15-2   2. Relief Request RR EN-15-2, Rev. 1 CNRO-2015-000 25 Page 3 of 3  cc: M. W. Woodby (ECH)
J. G. Browning (ANO)
K. J. Mulligan (GGNS)
E. W. Olson (RBS)
M. R. Chisum (WF3)
B. R. Sullivan (JAF)  L. M. Coyle (IPEC)
J. A. Dent (PIL)  A. J. Vitale (PAL)
D. J. Mannai (WPO)
G. H. Davant (ECH)
All above w/o attachments NRC Region I Administrator NRC Region III Administrator NRC Region IV Administrator NRC Project Manager (ANO)  NRC Projec t Manager (GGNS)   NRC Project Manager (RBS)  NRC Project Manager (WF3)  NRC Project Manager (IPEC)  NRC Project Manager (JAF)  NRC Project Manager (P IL)  NRC Project Manager (PAL)  NRC Senior Resident Inspector (ANO)
NRC Senior Resident Inspector (GGNS)
NRC Senior Resident Inspector (RBS)
NRC Senior Resident Inspector (WF3)
NRC Senior Resident Inspector (IPEC)
NRC Senior Resident Inspector (JAF)
NRC Senior Resident Inspector (PIL)
NRC Senior Resident Inspector (PAL)

ATTACHMENT 1 CNRO-2015-00025  RESPONSE TO NRC RAI REGARDING RELIEF REQUEST RR EN-15-2      to CNRO-2015-00025 Page 1 of 5    RESPONSE TO NRC RAI REGARDING RELIEF REQUEST RR EN-15-2 By letter dated August 20, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15232A711), Entergy Operations Inc. and Entergy Nuclear Operations, Inc.,(Entergy) requested the Nuclear Regulatory Commission (NRC) to authorize relief from Section Xl of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for the specific repair/replacement activity identified in contingency Relief Request RR EN 2. The contingency Relief Request RR EN 2 provided alternative repair for degrading moderate energy Class 2 and 3 piping using ASME Code Case N
-786-1 at Arkansas Nuclear One (ANO), Units 1 & 2; Grand Gulf Nuclear Station (Grand Gulf), Unit 1; James A. Fitzpatrick Nuclear Power Plant (FitzPatrick); Indian Point Energy Center (IPEC), Units 2 & 3; Palisades Nuclear Plant (PLP); Pilgrim Nuclear Power Station (PNPS); River Bend Station (River Bend), Unit 1; and Waterford 3 Steam Electric Station (Waterford)
. The NRC staff has reviewed the request provided and determined that additional information is required in order to complete its review.
The questions and their associated responses are provided below.
: 1. The table in Section 2 of the relief request shows that the third ISI interval at Grand Gulf is from May 31, 2008 to June 1, 2017. The fourth ISI interval at Fitzpatrick is from March 1, 2007 to December 31, 2016. The third ISI interval at River Bend is from May 31, 2008 to November 30, 2017. The third ISI interval at Waterford is from May 31, 2008 to June 30, 2017. For these four units, the ISI intervals are less than 10 calendar years. Please confirm that these end dates are correct and clarify why their ISI intervals are less than 10 calendar years.
Entergy Response:
The end dates for the ISI intervals at Grand Gulf, FitzPatrick , River Bend, and Waterford are correct as specified in the table in Section 2 of the relief request. Although the ISI intervals are less than 10 years (120 months), this is an acceptable practice according to IWA-2431(d)(1)
, which allows ISI intervals to be reduced or extended by as much as one year provided successive intervals are not altered by more than one year from the original pattern of intervals. Specifically, IWA
-2431(d)(1) states:
 "Each inspection interval may be reduced or extended by as much as one year. Adjustments shall not cause successive intervals to be altered by more than one year from the original pattern of intervals."
Although not mentioned by the NRC in this RAI, the present ISI intervals for ANO
-1, IPEC-2, and PLP are also less than 10 years (120 months). But, once again, the ISI intervals for these plants were reduced by one year or less as allowed by IWA
-2431(d)(1).
: 2. Section 2 of the relief request states that ASME Code, Section XI repair/replacement activities at all Entergy nuclear plants are performed in accordance with a standardized Repair/Replacement Program that is based on a common Edition/Addenda of ASME Section XI which, at present, is the 2001 Edition/ 2003 Addenda. However, the table in    to CNRO-2015-00025 Page 2 of 5    Section 2 shows that the code of record at present for Indian Point Unit 2, Palisades, and Pilgrim is the 2007 Edition through 2008 Addenda.
: a. Please clarify whether at present these three units use 2001 Edition through 2003 Addenda to perform repairs at their plant even though their code of record is the 2007 Edition through 2008 Addenda.
: b. If the answer to (a) above is yes, please provide rationale. Entergy Response:
: a. All Entergy nuclear plants including IPEC
-2, PLP, and PNPS presently perform repair and replacement activities in accordance with the 2001 Edition/2003 Addenda of ASME Section XI. Entergy has added Note 4 to the table in Section 2 (of the Revision 1 of the subject Relief Request) to clarify this point.
: b. The rationale or bases for the response to RAI
-2.a. is as follows:
IPEC-2 and PLP:  As stated above, IPEC
-2 and PLP perform repair and replacement activities to the 2001 Edition/2003 Addenda. However, the ISI Code of Record for the present or 4 th intervals at IPEC
-2 and PLP is also the 2001 Edition/ 2003 Addenda, not the 2007 Edition/2008 Addenda. Because the present or 4 th ISI intervals at IPEC
-2 and PLP end prior to the requested NRC relief request approval date of 8/20/16, the table only includes ISI interval information applicable to the 5 th ISI intervals for these plants which start on 12/13/15 (PLP) and 6/1/16 (IPEC
-2). Note 2 to the table states:
 "The 4 th ISI intervals for IPE C-2 and PLP end prior to the requested relief request approval date. Therefore, Entergy requests the NRC to approve this alternative for the 5 th IPEC-2 and PLP ISI intervals."
As clarification, Entergy has revised the table to include ISI information for the 4 th ISI intervals at IPEC
-2 and PLP.
PNPS:  PNPS updated its ISI Code of Record for the 5 th interval on 7/1/15 to the 2007 Edition/2008 Addenda as shown in the table. However, prior to the ISI update, Entergy submitted relief request (PPR)
-26 [ADAMS Accession No. ML14342B001] and requested NRC approval to allow PNPS to perform repair/replacement activities, pressure testing, and NDE in accordance with the 2001 Edition/2003 Addenda until Entergy updates the code basis of these programs in December 2017.
The NRC approved the PNPS relief request in a safety evaluation dated June 19, 2015 (TAC NO. ME5432), [ADAMS Accession No. ML15166A401]. The submittal of the PNPS relief request is consistent with past Entergy practice.
to CNRO-2015-00025 Page 3 of 5    Entergy has long
-maintained standardized repair/ replacement, pressure testing, and NDE programs across its nuclear fleet. Procedures for these programs are based on a common Edition/Addenda of ASME Section XI, which, at present, is the 2001 Edition/2003 Addenda. While ISI program plans are controlled on a site
-by-site basis, the repair/replacement, pressure testing, and NDE programs are administered under a set of corporate procedures that are used at all Entergy sites. This approach allows Entergy to leverage knowledge from all of its plants when addressing code and regulatory issues. Without this approach, Entergy would have to develop and maintain two sets of procedures for these programs based on two different Codes of Record. Below is a list of Entergy requests for alternatives that are similar to the PNPS relief request and previously approved by the NRC.  "Relief  Request ISI
-2008-1, Use of Later Edition and Addenda of ASME Code, Section XI for Repair and Replacement, Pressure Testing, and Non
-Destructive Testing Activities 
-Vermont Yankee Nuclear Power Station (TAC NO. ME0239)," dated April 30, 2009 [ADAMS Accession No. ML091170111]
  "Relief Request ISI
-2008-1, Use of Later Edition and Addenda of ASME Code, Section XI for Repair and Replacement, Pressure Testing, and Nondestructive Testing Activities 
- Pilgrim Nuclear Power Station (TAC NO. ME0238)," dated April 30, 2009 [ADAMS Accession No. ML091130456]
  "Arkansas Nuclear One, Unit 2 
- ISI-2007-1, Request to Use a Later Edition and Addenda of American Society of Mechanical Engineers Boiler and Pressure Vessel Code (TAC NO. MD6603)," dated December 20, 2007 [ADAMS Accession No. ML073390442]
  "Vermont Yankee Inservice Inspection Program for the Fifth Ten
-Year Interval," dated March 27, 2013 [ADAMS Accession No. ML13092A204], supplemented June 12, 2013 [ADAMS Accession No. ML13169A057], and August 7, 2013
[ADAMS Accession No. ML13224A243] and approved August 22, 2013 (TAC NO. MF1194), [ADAMS Accession No. ML13228A197]
Finally, Entergy has made minor changes to Section 2, Page 2 of 8 to further clarify that specific ISI related activities pertinent to performance of repair/replacement activities, pressure testing, and NDE are presently performed in accordance with the 2001 Edition/2003 Addenda.
: 3. Section 5, page 3, of the relief request states in part that:
The Code Case requires that the cause of the degradation be determined, and that the extent and rate of degradation in the piping be evaluated to ensure there are no other unacceptable locations within the surrounding area that could affect the integrity of the repaired piping.
The extent of condition inspection should include inspection of similar piping systems at the plant, not simply "the unacceptable locations within the surrounding area". Please discuss the extent of condition inspection if a piping system is discovered to be leaking.
to CNRO-2015-00025 Page 4 of 5    Entergy Response:
Code Case N
-786-1 is a repair code case that provides an alternative to the internal weld repair and replacement rules of IWA
-4400. All other rules of IWA
-4000 apply unless otherwise stated. As such, Code Case N
-786-1 does not include requirements for performing extent of condition inspections at other piping locations or in similar piping systems. This approach is not unique to Code Case N
-786-1; it is consistent with other ASME Section XI Codes Cases such as N
-561-2, N-562-2, N-661-2, and N-789-1. While all of these Code Cases specify rules for correcting degraded conditions in Class 2 and 3 piping by outside diameter wall thickness restoration or reinforcement, none of them include requirements for performing extent of condition inspections at other piping locations or in similar piping systems. It is also worth noting that all of these Code Cases, with the exception of N
-789-1, have been conditionally approved in Regulatory Guide 1.147. In conditionally approving these cases, the NRC did not impose extent of condition inspection requirements on any of these Code Cases.
Extent of condition, while not addressed by Code Case N
-786-1 or IWA-4000 is important and must be evaluated. However, it is addressed separately, outside of the ASME Code, in accordance with the Owners' operability procedures and corrective action program. For example, when leakage or a degraded condition is identified in a Class 2 or 3 component at an Entergy nuclear plant, an operability evaluation is required. As part of the immediate operability determination, an extent of condition assessment must be performed to comply with Entergy's operability procedure. Extent of condition assessments of degraded conditions are also required by Entergy's corrective action program.
Note: Owner operability procedures and processes are based on NRC Inspection Manual 0326, Operability Determinations & Functionality Assessment for Conditions Adverse to Quality or Safety. 4. The relief request and Code Case N
-786-1 do not address the inspection requirements for cavitation. The degradation rate caused by cavitation can be unpredictable and requires rigorous inspection. For pipe degradation caused by cavitation, please discuss the inspection method and inspection frequency of the repaired pipe location.
Entergy Response:
As stated in the Inquiry and Reply, Code Case N
-786-1 states that the code case may be used to repair degraded carbon steel piping experiencing internal wall thinning due to localized erosion, corrosion, pitting or cavitation. Therefore, the Inservice Inspection monitoring requirements in Section 8 of the code case apply to all degraded conditions including cavitation. These requirements are summarized below:  Type A and Partial
-Structural Type B Reinforcement Sleeves [Para. 8(d) and 8(e)]
Visual monitoring shall be performed at least monthly for evidence of leakage Maximum service life of these reinforcement sleeves is the time to the end of the next refueling outage.
to CNRO-2015-00025 Page 5 of 5     Type B Full
-Structural Reinforcement Sleeves [Para. 8(c)]
Thickness monitoring shall be performed at least every refueling outage to verify that minimum design thicknesses are not violated. More frequent thickness monitoring shall be performed when warranted by the observed degradation rates. In all cases, the design thickness is required to be maintained at least until the performance of the next scheduled thickness inspection.
Maximum service life of these reinforcement sleeves is as determined by the design. The inspection monitoring requirements in Section 8 of Code Case N
-786-1 are more stringent than those in Revision 0 of Code Case N
-786. In fact, they are consistent with those proposed in Exelon's relief request to use Code Case N
-786 dated April 28, 2014 (ML14119A289) and approved by the NRC in its safety evaluation dated July 31, 2014 (ML14175B593).
In conclusion, Entergy believes that the inspection requirements in Section 8 of Code Case N-786-1, as summarized above, provide high assurance that piping repaired due to cavitation will not fail or degrade below minimum design thickness requirements. In performing thickness monitoring, Entergy intends to use ultrasonic thickness measuring techniques unless direct measurement is feasible and more accurate.
: 5. Please discuss whether welding involved in the sleeve repair will follow the ASME Code, Section IX which is not referenced in either the relief request or Code Case N
-786-1. Entergy Response:
All welding procedures and welders involved in the sleeve repair will be qualified in accordance with ASME Section IX. Welding qualification requirements are specified in paragraphs 1(b) and 5(e) of Code Case N
-786-1. 6. Page 6 of the relief request states in part that:
Some piping systems are required to be functional and cannot be repaired during refueling outages. The repair of this piping can only be performed when the plant is operating. For this unique case, Type A and partial
-structural Type B reinforcing sleeves will be removed prior to, but no later than, the refueling outage unless specific regulatory relief is obtained.
Please confirm that the repair will be removed prior to the refueling outage that is scheduled at the end of the fuel cycle during which the repair is performed.
Entergy Response:
For piping systems which must remain functional during refueling outages, Entergy will remove Type A and partial
-structural Type B reinforcing sleeves prior to the refueling outage that is scheduled at the end of the fuel cycle during which the repair is performed.

ATTACHMENT 2  CNRO-2015-000 25  RELIEF REQUEST RR EN-15-2, Rev. 1 Attachment 2 to CNRO-2015-000 25 Page 1 of 8    RELIEF REQUEST RR EN-15-2, Rev. 1   1. American Society of Mechanical Engineers  (ASME) Code Component(s) Affected This relief request applies to all ASME Class 2 and 3 moderate energy carbon steel piping systems. Moderate energy is defined as less than or equal to 200&deg;F (93&deg;C) and less than or equal to 275 psig (1.9 MPa) maximum operating conditions
. 2. Applicable Code Edition and Addenda The following table identifies the ASME Section XI Code of Record for performing Inservice Inspection (ISI) activities at each Entergy site.
Plant ISI Interval ASME Section XI Edition/Addenda (Note 4) Interval Start Interval End Arkansas Nuclear One Unit 1 (ANO
-1) (Note 1) 4 5 2001 Edition / 2003 Addenda 2007 Edition/2008 Addenda (Note 3) 5/31/08 5/31/17 5/30/17 5/30/2 7 Arkansas Nuclear One Unit 2 (ANO
-2) 4 2001 Edition / 2003 Addenda 3/26/10 3/2 5/20 Grand Gulf Nuclear Station (GGNS) (Note 1) 3 4 2001 Edition / 2003 Adde nda 2007 Edition/2008 Addenda (Note 3) 5/31/08 6/2/17 6/1/17 6/1/27 Indian Point Energy Center Unit 2 (IPEC-2) (Note 2) 4 5 2001 Edition / 2003 Addenda 2007 Edition / 2008 Addenda 3/1/07 6/1/16 5/31/16 5/31/26 Indian Point Energy Center Unit 3 (IPEC-3) 4 2001 Edition / 2003 Addenda 7/21/09 7/20/19 James A. FitzPatrick (JAF) (Note 1) 4 5 2001 Edition / 2003 Addenda 2007 Edition/2008 Addenda (Note 3) 3/1/07 1/1/17 12/31/16  12/31/2 6 Palisades (PLP)
(Note 2)  4 5 2001 Edition / 2003 Addenda 2007 Edition
 / 2008 Addenda 12/1 3/06 12/13/15 12/12/1 5 12/12/25 Pilgrim Nuclear Power Station (PNPS) 5 2007 Edition / 2008 Addenda 7/1/15 6/30/25 River Bend Station (RBS)
(Note 1)  3 4 2001 Edition / 2003 Addenda 2007 Edition/2008 Addenda (Note 3) 5/31/08 12/1/17 11/30/17 11/30/27 Waterford Unit 3 (WF3) (Note 1)  3 4 2001 Edition / 2003 Addenda 2007 Edition/2008 Addenda (Note 3) 5/31/08 7/1/17 6/30/17 6/30/27  Notes:  1) The 3 rd ISI intervals for GGNS, RBS, and WF3 and the 4 th ISI interval s for ANO-1 and JAF end within 1-1/2 years of the requested relief request approval date. Therefore, Entergy requests the NRC to approve this alternative for the 3 rd and 4 th GGNS, RBS, and WF3 intervals and 4 th and 5 th ANO-1 and JAF intervals. 2) T he 4 th ISI interval s for IPEC-2 and PL P end prior to the requested relief request approval date. Therefore, Entergy requests the NRC to approve this alternative for the 5 th IPEC-2 and PLP ISI interval s. 3) ANO-1, GGNS, JAF, RBS, and WF3 will update to the 2007 Edition/2008 Addenda except as otherwise required by the NRC in 10 CFR 50.55a(g)(4)(ii).
: 4) ASME Section XI repair/replacement activities, nondestructive examinations (NDE), and pressure testing are performed in accordance with the 2001 Edition/2003 Addenda.  

Attachment 2 to CNRO-2015-000 25 Page 2 of 8    The table above identifies the ASME Section XI Code of Record for performing ISI activities at each Entergy nuclear plant. However, it should be noted that ASME Section XI repair/
replacement activities, pressure testing, and NDE at all Entergy nuclear plants are performed in accordance with standardized programs that are based on a common Edition/Addenda of ASME Section XI which, at present, is the 2001 Edition/2003 Addenda. As Entergy nuclear sites update their ISI Programs in accordance with 10 CFR 50.55a(g)(4)(ii), Entergy will also update the Code bases of the Repair/Replacement, Pressure Testing, and NDE Program s to a later Edition/Addenda of ASME Section XI. The planned update to these programs is scheduled for 201 7 and no later than December 31, 2017. The update must comply with 10 CFR 50.55a and, where approp riate, in accordance with 10 CFR 50.55a(g)(4)(iv) and 10 CFR 50.55a(z).
(See Reference 2.) 3. Applicable Code Requirements The Editions/Addenda of ASME Section XI for which the alternative is requested are specified in Section 2, above. Subsection IWA
-4 000 of these Editions and Addenda provide requirements for welding, brazing, metal removal, and installation of repair/replacement activities.

===4. Reason for Request===
IWA-4000 requires replacement or internal weld repair of wall thinning conditions resulting from degradation to be in accordance with the Owner's Requirements and the original or later Construction Code. However, the repair and replacement provisions of IWA
-4000 cannot always be utilized when degradation or leakage is identified during plant operations. Other approved alternative repair or evaluation methods are not always practicable because of wall thinness and/or moisture issues.  

One reason for this request is to permit installation of technically sound repairs to provide adequate time for evaluation, design, material procurement, planning, and scheduling of an appropriate permanent repair or replacement of the defective piping, considering the impact on system availability, maintenance rule applicability, and availability of replacement materials.
The other reason is to permit installation of long
-term repairs in the form of full
-structural Type B reinforcing sleeves for locally degraded portions of piping systems. The design, construction
, and inservice monitoring of such sleeves provide a technically sound equivalent replacement for the segment of piping that is encompassed, comparable to or exceeding the level of quality and safety associated with a permanent ASME Code repair or replacement.

In either case, without this repair option, compliance with the specified requirements of IWA
-4000 could in some cases necessitate taking a system out of service, resulting in extended technical specification actions and higher risks associated with loss of safety system availability.
In other cases, plant shutdown could be necessary, resulting in higher risks associated with an unnecessary plant transient and loss of safety system availability as compared to maintaining the plant online.
All other ASME Code Section XI requirements for which relief is not specifically requested will remain applicable, including third
-party review by the Authorized Nuclear Inservice Inspector.

Attachment 2 to CNRO-2015-000 25 Page 3 of 8    5. Proposed Alternative and Basis for Use Pursuant to 10 CFR 50.55a(z)(2), Entergy proposes to implement the requirements of Code Case N-786-1 for repair of degradation in Class 2 and 3 moderate energy carbon steel piping systems resulting from mechanisms such as localized erosion, corrosion, cavitation, or pitting, but excluding conditions involving any form of cracking. These types of defects are typically identified by small leaks in the piping system or by pre
-emptive, non
-code required examinations performed to monitor the degradation mechanisms.
The alternative repair technique described in Code Case N
-786-1 involves the application of Type A and Type B full encirclement sleeve halves welded together with full penetration longitudinal seam welds to reinforce the structural integrity in the degraded area. In the case of Type B reinforcing sleeves, the ends are also welded to the piping in order to restore or maintain pressure integrity. This repair technique will be used when it is determined that the repair method is suitable for the particular defect or degradation being resolved without flaw removal. Code Case N
-786-1 is included in Enclosure 1 of this Attachment.
The Code Case requires that the cause of the degradation be determined, and that the extent and rate of degradation in the piping be evaluated to ensure there are no other unacceptable locations within the surrounding area that could affect the integrity of the repaired piping.
Any areas showing signs of degradation will be included in the Owner's plan for thickness monitoring of full-structural Type B reinforcing sleeves. The area of evaluation will be dependent on the degradation mechanism present, but will extend at least
("R" and "T nom" are the radius and nominal thickness of the pipe, respectively) beyond the edge of any sleeve attachment weld, as required by the Code Case. If the cause of the degradation is not determined, the maximum permitted service life of any reinforcing sleeve will be the time until the next refueling outage.

"Full-structural Type B" means the sleeve and attachment welds alone maintain full capability to withstand structural (mechanical) and pressure loading for which the piping is presently designed without need for additional support or reinforcement, and without reliance on any of the piping that is encased by the sleeve. Type A and partial-structural Type B sleeves rely on the encased underlying piping to provide some structural (mechanical) and/or pressure retaining integrity.

Type B reinforcing sleeves may be applied to leaking systems by installing a gasket or sealant between the sleeve and the pipe as permitted by the Code Case, and then clamping the reinforcing sleeve halves to the piping prior to welding. If welding of any type of sleeve occurs on a wet surface, the maximum permitted life of the sleeve will be the time until the next refueling outage.

A baseline thickness examination will be performed for completed full
-structural Type B reinforcing sleeves, attachment welds, and surrounding areas, followed by similar thickness monitoring at a minimum of every refueling outage after installation. Full
-structural Type B sleeves shall be removed prior to infringing upon design minimum wall thickness.
Type A and partial
-structural Type B reinforcing sleeves completely encompass the degraded areas, are designed to accommodate predicted maximum degradation, and must be removed no later than the next refueling outage. The Code Case requires that these temporary sleeves be visually monitored for evidence of leakage at least monthly. If the areas containing the sleeves are not accessible for direct observation, monitoring shall be Attachment 2 to CNRO-2015-000 25 Page 4 of 8    accomplished by visual assessment of surrounding areas or ground surface areas above reinforcing sleeves on buried piping, or by monitoring of leakage collection systems, if available.   

Entergy implementation of Code Case N
-786-1 will include the following additional restrictions and clarifications:
: 1) When gasket material is used in accordance with paragraph 4(b) of the Code Case (water-backed applications), Entergy will also require removal of any residual moisture by heating prior to welding.
: 2) Regarding paragraph 8(c) and 8(c)(1) of the Code Case, Entergy will implement the thickness monitoring inspections of full
-structural Type B sleeves at every refueling outage, and will schedule more frequent thickness monitoring, when appropriate, based on degradation rates that are calculated using the reductions in thicknesses observed between scheduled thickness monitoring inspections.
: 3) Sections 1, 3, 5, and 6 of the Code Case specify that materials, design, installation, and examination of reinforcement sleeves shall be performed in accordance with the Construction Code or ASME Section III applicable to each Entergy plant. As allowed by IWA-4200 and IWA
-4411, later Editions and Addenda of the Construction Code or ASME Section III may be used provided any required reconciliations are performed. However, only Editions/Addenda of ASME Section III that have been approved by the NRC in 10 CFR 50.55a will be used.
: 4) Entergy performs repair/replacement activities in accordance with a fleet
-wide, standardized Repair/Replacement Program based on the 2001 Edition/ 2003 Addenda of ASME Section XI. Therefore, this Edition/Addenda of ASME Section XI will be used by all plants whenever the Code Case refers to IWA
-4000 until the C ode bases of the Repair/ Replacement Pr ogram is updated as explained in Section 2 of this request. 5) If a buried piping system carrying radioactive fluid is repaired using this alternative, Entergy will monitor for radioactive fluid leakage in accordance with the standard plant monitoring practices for all buried piping containing radioactive fluids.
Entergy is committed to implementation of Nuclear Energy Institute (NEI) 07
-07, "Industry Ground Water Protection Initiative 
- Final Guidance Document," dated August 2007, in addition to monitoring in accordance with ASME Code Case N
-786-1. Code Case N
-786-1 includes requirements for incorporating actual measured or estimated corrosion rates in the design of all reinforcing sleeves. For all sleeves, the initial degradation rate selected for design shall be equal to or greater than two (2) times the maximum rate observed at the location of the repair.
If the degradation rate for that location is unknown, an initial degradation rate of four (4) times the estimated maximum degradation rate for that or a similar system at the same plant site for the same degradation mechanism shall be applied.
If both the degradation rate for that location and the cause of the degradation are not conclusively determined, an initial degradation rate of four (4) times the maximum degradation rate observed for all degradation mechanisms for that system or a similar system at the same plant site shall be applied.
In addition, the Code Case imposes compensatory measures to account for any uncertainties in the corrosion rates used, thus providing reasonable assurance that structural integrity and leakage integrity will be maintained.
These measures include limiting the design life of Type A and partial
-structural Type B Attachment 2 to CNRO-2015-000 25 Page 5 of 8    sleeves to a maximum of one refueling cycle, and requiring on
-going monitoring of full-structural Type B sleeves as follows:
For full-structural Type B reinforcing sleeves including their partial penetration attachment welds and surrounding areas, the Code Case requires that a baseline thickness examination be performed followed by similar thickness monitoring inspections at a minimum of every refueling outage for the life of the repair. More frequent thickness monitoring examinations will be scheduled if maximum degradation rates observed during these inspections indicate that the design thickness required by the Construction Code or ASME Section III will be infringed upon prior to the next scheduled monitoring activity.
Type A and partial
-structural Type B reinforcing sleeves completely encompass the degraded areas, are designed to accommodate maximum predicted degradation, and must be removed no later than the next refueling outage. The Code Case requires that they be visually observed at least once per month to monitor for evidence of leakage. If the areas containing these types of sleeves are not accessible for direct observation, then monitoring will be accomplished by visual assessment of surrounding areas, or ground surface areas above such sleeves on buried piping, or by monitoring of leakage collection systems, if available.
When used on buried piping, the area of full
-structural Type B reinforcing sleeves must be physically accessible for the required examinations which could necessitate installation of removable barriers at the repair location in lieu of backfilling the pipe at that location. For Type A and partial
-structural Type B reinforcing sleeves installed on buried piping, the monitoring will be based on visual assessment as discussed above.
Code Case N
-786-1 restricts application of reinforcing sleeves to pipe and welded fittings, prohibiting their application on pumps, valves, expansion joints, vessels, heat exchangers, tubing, flanges, flanged joints, socket welded or threaded joints, or branch connection welds. In addition, the Code Case only permits branch connections to be installed on Type B reinforcing sleeves when required for filling or venting purposes during installation or leakage testing of the sleeve, and restricts such connections to Nominal Pipe Size (NPS) 1
" or smaller in size. Code Case N
-786-1 was approved by ASME Board on Nuclear Codes and Standards in January, 2015
. However, it has not been incorporated into Regulatory Guide 1.147, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1," and
, thus , is not available for application at nuclear power plants without specific NRC approval.
: 6. Duration of Proposed Alternative Use of the proposed alternative is requested for the duration of the ISI intervals identified in Section 2. In the case of GGNS, RBS, WF3, ANO-1, and JAF, approval of this relief request is anticipated within 1-1/2 year s prior to the end of the current ISI intervals; therefore, this request also includes the 4 th ISI intervals for GGNS , RBS, and WF3 and 5 th ISI intervals for ANO-1 and JAF.
Attachment 2 to CNRO-2015-000 25 Page 6 of 8    Code Case N
-786-1, paragraphs 3.1(a) and 3.1(b)(2) require that Type A and partial
-structural Type B reinforcing sleeves, including those installed during refueling outages or any time during an operating cycle, shall not remain in service beyond the next refueling outage, when a permanent repair or replacement must be performed. Entergy will comply with this requirement with the following clarifications:
Reinforcing sleeves installed before the end of the 10-year ISI interval will be removed during the next refueling outage after installation, even if that refueling outage occurs after the end of the 10
-year ISI interval. In this case, absent detrimental defects or degradation, duration of the proposed alternative would be until the first refueling outage after the end date of the ISI Interval for the applicable Entergy plant.
Some piping systems are required to be functional and cannot be repaired during refueling outages. The repair of this piping can only be performed when the plant is operating. For this unique case, Type A and partial
-structural Type B reinforcing sleeves will be removed prior to, but no later than, the refueling outage unless specific regulatory relief is obtained.
Full-structural Type B reinforcing sleeves may remain in
-service for the design life of the repair as specified in Code Case N
-786-1, paragraph 3.1(b)(1). Entergy commits to continued inservice thickness monitoring and evaluation in accordance with this alternativ e for any full
-structural Type B sleeve remaining installed after the end of the ISI intervals identified in Section 2.
: 7. Precedents A similar alternative was approved for application of Code Case N
-786 for thirteen (13) Exelon nuclear power plants (a total of 22 units) on July 31, 2014. Differences between that Code Case and Code Case N
-786-1 referenced in this relief request are as follows:
General Requirements
:    Paragraph 1(f) was added to restrict sleeve repairs to pipe and welded fittings, excluding other items including branch connection welds.
Initial Evaluation
:
Paragraph 2(a) was revised to require a minimum of of base metal beyond the attachment weld to be included in the evaluation
. Paragraph 2(b) was revised to require that surrounding areas showing signs of degradation be included in the Owner's plan for thickness monitoring.
Design General Requirements
:
Paragraph 3.2(a) references to N C-3100/3600 and ND-3100/3600 were corrected
. Paragraph 3.2(k) was revised to include requirements to use two (2) times the actual or four (4) times the estimated maximum corrosion rates for the design.
Attachment 2 to CNRO-2015-000 25 Page 7 of 8    Paragraph 3.2(o) was added to restrict installation of branch connections on reinforcing sleeves. Specific Requirements 
- Type B Sleeves
:    Paragraph 3.4(e) terminology was corrected to clarify its applicability to full structural sleeves. Water-backed Applications
:    Paragraph 4(b) was added to require precautions to be taken, such as installation of a gasket or sealant beneath the sleeve, to prevent welding on wet surfaces.
Examination:    Paragraph 6(e) was revised to correct references to NC-5320/5330 and ND-5320/5330. Pressure Testing
:    Paragraph 7 was revised to require installation of pressure test taps on Type B reinforcing sleeves for piping that has not been breached.
Inservice Examination
:   Paragraph 8(b) was revised to clarify requirements for obtaining baseline thickness measurements for full-structural Type B reinforcing sleeves
. Paragraph 8(c) was revised to require similar thickness inspections of full-structural Type B reinforcement sleeves to be performed at least every refueling outage
. Paragraph 8(c)(1) was added to clarify that more frequent thickness inspections shall be scheduled when warranted by observed degradation rates
. Paragraph 8(c)(2) was added to address accessibility for full
-structural sleeves on buried piping to accommodate scheduled inspections
. Paragraph 8(d) was added to require monthly leakage monitoring of Type A and partial
-structural Type B sleeves
. Paragraph 8(e) was revised to clarify when a temporary Type A or partial
-structural Type B reinforcing sleeve is required to be removed
. Paragraph 8(f) was clarified to permit removal of reinforcement sleeves, for which the degradation method was not determined, any time prior to the end of the next refueling outage. 8. References
: 1) Exelon Generation Company, LLC, Safety Evaluation for Use of Code Case N
-786, July 31, 2014; Adams Accession No. ML14175B593.

Attachment 2 to CNRO-2015-000 25 Page 8 of 8    2) Entergy letter to NRC; Request for Approval of Pilgrim Relief Request (PRR)
-26, Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(i) to Maintain ISI Related Activities on the 2001E through 2003A
; November 26, 2014; Adams Accession No. ML14342B001
: 9. Enclosure  1. Code Case N
-786-1, Alternative Requirements for Sleeve Reinforcement of Class 2 and 3 Moderate
-Energy Carbon Steel Piping, Section XI, Division 1

CNRO-2015-000 25 RELIEF REQUEST RR EN-15-2, Rev. 1 ENCLOSURE to ATTACHMENT 1 ASME CODE CASE N
-786-1,  ALTERNATIVE REQUIREMENTS FOR SLEEVE REINFORCEMENT OF CLASS 2 AND 3 MODERATE
-ENERGY CARBON STEEL PIPING, SECTION XI, DIVISION 1}}