GNRO-2011/00009, Request for Alternative GG-ISI-013 Proposed Alternative to 10 CFR 50.55a Examination Requirements for Reactor Pressure Vessel Weld Inspections

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Request for Alternative GG-ISI-013 Proposed Alternative to 10 CFR 50.55a Examination Requirements for Reactor Pressure Vessel Weld Inspections
ML110960459
Person / Time
Site: Grand Gulf Entergy icon.png
Issue date: 04/06/2011
From: Perino C
Entergy Nuclear Operations
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
GG-ISI-013, GNRO-2011/00009
Download: ML110960459 (14)
v • d • e


Text

tergy ODfliratic:ms. Inc, GNRO-2011/00009 April 6, 2011 U, S, Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Request for Alternative GG-ISI-013 Proposed Alternative to 10 CFR 50,55a Examination Requirements for Reactor Pressure Vessel Weld Inspections Docket No. 50-416 License No, NPF-29

Dear Sir or Madam:

Pursuant to 10 CFR 50.55a(a)(3)(i), Entergy Operations, Inc. (Entergy) requests NRC approval of a proposed alternative to American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code,Section XI, Subarticle IWB-2500. Specifically, Entergy proposes to utilize the 25% sampling provision of ASME Code Case N-702, Alternative Requirements for Boiling Water Reactor (BWR) Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1, at the Grand Gulf Nuclear Station (GGNS),

Proposed Request for Alternative GG-ISI-013 is contained in Attachment 1 with supporting information provided in Attachment 2. Entergy requests GG-ISI-013 for the third 10-year interval of the GGNS Inservice Inspection (lSI) Program and requests approval by December 31, 2011 to support planning for the next refueling outage, This letter contains no new regulatory commitments.

If you have any questions concerning this letter, please contact Mr. Ernest Rufus at (601) 437-6582, Respectfully, CP/jas

GNRO-2011/00009 2of2 Attachments: 1. Grand Gulf Nuclear Station (GGNS) Third 10 year Interval Inservice Inspection Program Request for Alternative GG-ISI-013

2. Responses to BWRVIP-1 08 Plant-Specific Applicability Criteria cc: Mr. Elmo Collins Jr.

Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 U. S. Nuclear Regulatory Commission AnN: Mr. A. B. Wang, NRR/DORL (w/2)

Mail Stop OWFN/8 B1 Washington, DC 20555-0001

ATTACHMENT 1 GNRO-2011/00009 GRAND GULF NUCLEAR STATION (GGNS)

THIRD 10 YEAR INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR ALTERNATIVE GG-ISI-013

Attachment 1 to GNRO-2011/00009 Page 1 of 7 GRAND GULF NUCLEAR STATION (GGNS)

REQUEST FOR ALTERNATIVE GG-ISI-013 Components/Numbers: 1. Nozzle-to-Vessel Welds (see Table 1)

2. Nozzle Inner Radius Sections (see Table 2)

Code Classes: American Society of Mechanical Engineers (ASME) Code Class 1 Examination Category: 8-0, Full Penetration Welds of Nozzles in Vessels

==

Description:==

1. Nozzle-to-Vessel Welds
2. Nozzle Inner Radius Sections Item Number(s): 83.90, 83.100 Unit / Inspection Interval GGNS, 3rd 10-year interval June 2008 - June 2017 Applicability:

I. Code Requirement(s)

ASME Section XI, Table IW8-2500-1, "Examination Category 8-0, Full Penetration Welds of Nozzles in Vessels - Inspection Program 8" (Reference 1):

  • Item 83.90 - Requires a volumetric examination of Reactor Vessel Nozzle-to-Vessel Welds.
  • Item 83.100 - Requires a volumetric examination of Reactor Vessel Nozzle Inside Radius Sections.

II. Alternative Requested Currently, all Class 1 nozzle-to-vessel weld and nozzle inner radius examinations are required during the current inservice inspection (lSI) interval (June 2008 - June 2017).

The 25 % sampling provision of ASME Code Case N-702 (Reference 2) provides a significant reduction in worker radiological exposure. Entergy estimates this reduction to be at least 19 Rem over the Third 10 year lSI Interval.

III. Proposed Alternative Examinations Pursuant to 10 CFR 50.55a(a)(3)(i), Entergy requests an alternative from performing the ASME Code required examinations on 100% of the nozzle-to-vessel assemblies and nozzle inner radius sections identified in Tables 1 and 2, respectively. Specifically, Entergy proposes to adopt ASME Code Case N-702, which allows examination of a minimum of 25% of the nozzle-to-vessel welds and nozzle inner radius sections, including at least one nozzle from each system and nominal pipe size. For each of the

Attachment 1 to GNRO-2011/00009 Page 2 of 7 identified nozzle assemblies, both the inner radius and the nozzle-to-vessel weld will be examined.

The indications on the Nozzle to Vessel welds and Inner Radius welds listed in Table 1 and Table 2 were recorded and evaluated in accordance with ASME Section XI and determined to be within the allowable limits of IWB-3000 and as such were NOT reportable. Based on sizing and evaluation all recordable indications listed below are believed to be geometric and/or fabrication related. In addition, none of the recorded indications required repair. Refer to Table 1 and Table 2 below in the Exam Results column for the disposition of indications for each applicable nozzle weld examined at GGNS.

Table 1: Nozzle-to-Vessel Weld Examinations Item Number Comp.ID Item Description Exam Results 83.90 N01A-KA 24" RPV Outlet Nozzle to Vessel NRI (No Recordable Indications) 83.90 N018-KA 24" RPV Outlet Nozzle to Vessel NRI 83.90 N02A-KA 12" RCS Inlet Nozzle to Vessel NRI 83.90 N028-KA 12" RCS Inlet Nozzle to Vessel NRI 83.90 N02C-KA 12" RCS Inlet Nozzle to Vessel NRI 83.90 N02D-KA 12" RCS Inlet Nozzle to Vessel NRI Spot Indications in the base metal 83.90 N02E-KA 12" RCS Inlet Nozzle to Vessel recorded. No indication of growth from previously recorded examinations.

83.90 N02F- 12" RCS Inlet Nozzle to Vessel NRI 83.90 N02G-KA 12" RCS Inlet Nozzle to Vessel NRI 83.90 N02H-KA 12" RCS Inlet Nozzle to Vessel NRI 83.90 83.90 N02J-KA N02K-KA 12"~~

12" RC NRI NRI 83.90 N02M-KA 12" RCS Inlet Nozzle to Vesse NRI 83.90 N02N-KA 12" RCS Inlet Nozzle to Vessel NRI Spot Indications in the base metal 83.90 N03A-KA 24" Main Steam Nozzle to Vessel recorded. No indication of growth from previously recorded examinations 8ase Metal Indications recorded. No 83.90 N038-KA 24" Main Steam Nozzle to Vessel indication of growth from previously recorded examinations 83.90 N03C-KA 24" Main Steam Nozzle to Vessel NRI Nozzle Cladding Cut 8ack Geometry 83.90 N03D-KA 24" Main Steam Nozzle to Vessel Indication.

83.90 N04A-KA 14" Feed water Nozzle to Vessel Not Applicable 83.90 N048-KA 14" Feed water Nozzle to Vessel Not Applicable 83.90 N04C-KA 14" Feed water Nozzle to Vessel Not Applicable 83.90 N04D-KA 14" Feed water Nozzle to Vessel Not Applicable 83.90 N04E-KA 14" Feed water Nozzle to Vessel Not Applicable 83.90 N04F-KA 14" Feed water Nozzle to Vessel Not Applicable

Attachment 1 to GNRO-2011/00009 Page 3 of 7 Table 1: Nozzle-to-Vessel Weld Examinations Item Number Comp.ID Item Description Exam Results Geometric Indication due to Core Spray 8racket Pad Buildup and Nozzle Cladding 83.90 N05A-KA 12" Core Spray Nozzle to Vessel Strip Backing. No indication of growth from previously recorded examinations Geometric Indication due to Core Spray Bracket Pad Buildup and Nozzle Cladding 83.90 N05B-KA 12" Core Spray Nozzle to Vessel Strip 8acking. No indication of growth from previously recorded examinations 12" RHR/LPCI Inlet Nozzle to NRI 83.90 N06A-KA Vessel 12" RHR/LPCI Inlet Nozzle to NRI 83.90 N06B-KA Vessel 12" RHR/LPCI Inlet Nozzle to NRI B3.90 N06C-KA Vessel 15.5" RCIC Top Head Spray B3.90 N07-KA I

Inlet Nozzle NRI 15.5" RCIC Top Head Spray B3.90 N08-KA Spare Inlet Nozzle NRI 4" Jet Pump Instrument Nozzle to Inner Diameter (10) cladding cut-back and 83.90 N09A-KA Vessel nozzle bore geometry indications One Laminar reflector in the base metal 4" Jet Pump Instrument Nozzle to 83.90 N09B-KA recorded. 10 cladding cut-back and nozzle Vessel bore geometry indications recorded.

83.90 N10-KA 4" CRD Return Nozzle to Vessel Not Applicable 8" Vibration Instrument Nozzle to B3.90 N16-KA Vessel Not Applicable to GNRO-2011/00009 Page 4 of 7 Table 2: Nozzle Inner Radius Examinations Item Number Comp.ID Item Description Exam Results B3.100 N01A-IR 24" RPV Nozzle Inner Radius NRI B3.100 N01B-IR 24" RPV Nozzle Inner Radius NRI B3.100 N02A-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02B-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02C-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02D-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02E-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02F-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02G-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 NRI N02H-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02J-IR 12" RCS Inlet Nozzle Inner Radius B3.100 N02K-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02M-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N02N-IR 12" RCS Inlet Nozzle Inner Radius NRI B3.100 N03A-IR 24" Main Steam Nozzle Inner Radius NRI B3.100 N03B-IR 24" Main Steam Nozzle Inner Radius NRI B3.100 N03C-IR 24" Main Steam Nozzle Inner Radius NRI B3.100 N03D-IR 24" Main Steam Nozzle Inner Radius NRI Not Applicable B3.100 N04A-IR 14" Feed water Nozzle Inner Radius B3.100 N04B-IR 14" Feed water Nozzle Inner Radius Not Applicable B3.100 N04C-IR 14" Feed water Nozzle Inner Radius Not Applicable B3.100 N04D-IR 14" Feed water Nozzle Inner Radius Not Applicable B3.100 N04E-IR 14" Feed water Nozzle Inner Radius Not Applicable B3.100 N04F-IR 14" Feed water Nozzle Inner Radius Not Applicable Geometric reflectors B3.100 N05A-IR 12" Core Spray Nozzle Inner Radius recorded.

N05B-IR 12" Core Spray Nozzle Inner Radius B3.100 NRI N06A-IR 12" RHR/LPCI Inlet Nozzle Inner Radius NRI B3.100 N06B-IR 12" RHR/LPCI Inlet Nozzle Inner Radius B3.100 NRI to GNRO-2011/00009 Page 5 of 7 Table 2: Nozzle Inner Radius Examinations Item Number Comp.ID Item Description Exam Results N06C-IR 12" RHR/LPCI Inlet Nozzle Inner Radius 83.100 NRI 15.5" RCIC Top Head Spray Inlet Nozzle 83.100 N07-IR Inner Radius NRI 15.5" RCIC Top Head Spray Inlet Spare 83.100 N08-IR Nozzle Inner Radius NRI 4" Jet Pump Instrument Nozzle Inner N09A-IR 83.100 Radius NRI 4" Jet Pump Instrument Nozzle Inner N098-IR 83.100 Radius NRI N10-IR 4" CRD Return Nozzle Inner Radius 83.100 Not Applicable 8" Vibration Instrument Nozzle Inner N16-IR 83.100 Radius NRI Table 3: Nozzle Assemblies to be Examined Group Description of Nozzle Assemblies Quantity Minimum Examination N01 24" Recirculation Outlet 2 1 N02 12" Recirculation Inlet 12 3 N03 24" Main Steam Line 4 1

~

12" Core Spray 2 1 12" RHR/LPCllnlet 3 1 15.5" RCIC Top Head Spray Inlet Nozzle 1 1 NO?

N08 15.5" RCIC Top Head Spray Inlet Spare Nozzle 1 1 N09 4" Jet Pump Instrumentation 2 1 N16 8" Vibration Instrumentation 1 1 The ASME Code requires that all thirty five (35) nozzle assemblies listed in Tables 1 and 2 be examined during each lSI inspection interval. Table 3 identifies those nozzle assemblies to be examined during the Third 10 year lSI Interval when adopting GG-ISI-013.

ASME Code Case N-702 excludes the Feed water (N04) and Control Rod Drive Return (N 10) nozzle assemblies; therefore, these are not within the scope of this request and will continue to meet the requirements of ASME Code Table IWB-2500-1.

to GNRO-2011/00009 Page 6 of 7 ASME Code Case N-702 stipulates that the VT-1 visual examination method may be used in lieu of the volumetric examination method for the inner radius sections (Item No.

B3.100). GGNS adopted ASME Code Case N-648-1, Alternative Requirements for Inner Radius Examination of Class 1 Reactor Vessel Nozzles, with the provisions stipulated in Regulatory Guide 1.147, in the GGNS Third Interval lSI Program Plan.

Code N-648-1 contains a similar allowance; therefore, GGNS may perform examinations on inner radius sections with either the VT-1 or the volumetric examination method.

IV. Basis for Alternative Electric Power Research Institute (EPRI) Technical Report 1003557, BWR Vessel and Internals Project (BWRVIP), Technical Basis for the Reduction of Inspection Requirements for the Boiling Water Reactor Nozzle-to- Vessel Shell Welds and Nozzle Blend Radii, (Reference 2) provides the basis for ASME Code Case N-702. The evaluation found that the failure probability due to a Low Temperature Overpressure event at the nozzle blend radius region and nozzle-to-vessel shell weld is very low (i.e.,

6

< 1 X 10- for 40 years) with or without lSI. The report concludes that inspection of 25%

of each nozzle type is technically justified.

BWRVIP-108 was originally submitted to the NRC for review and approval via BWRVIP letter 2002-323 on November 25,2002 (Reference 4) and supplemented by Tennessee Valley Authority (TVA) letter dated November 15,2004 (Reference 5), and BWRVIP letters dated July 25, 2006, and September 13, 2007 (References 6 and 7).

On December 19, 2007, the NRC issued a Safety Evaluation Report (SER) approving the use of BWRVIP-1 08 (Reference 8). Section 5 of the SER states that each licensee should, within the request for alternative, demonstrate the plant meets the specified criteria. This demonstration is provided in Attachment 2.

V. Conclusion This proposed alternative to use ASME Code Case N-702 in lieu of the ASME Code,Section XI requirements provides an acceptable level of quality and safety in accordance with 10 CFR 50.55a(a)(3)(i) for all applicable RPV nozzle-to-vessel welds and nozzle inside radius sections excluding the N04 and N10 nozzles listed in Tables 1 and 2, identified respectively.

VI. Duration of Purposed Relief Request Upon approval by NRC, this request for alternative will be utilized during the Third lSI Inspection Interval for the nozzle assemblies excluding the N04 and N10 nozzles listed in Tables 1 and 2, identified respectively.

VII. Precedents The NRC Staff has recently approved similar requests for alternative for the following plants:

VIII. References

1. ASME Section XI 2001 Edition 2003 Addenda, Table IWB-2500-1
2. ASME Boiler and Pressure Vessel Code, Code Case N-702, "Alternative Requirements for Boiling Water Reactor (BWR) Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1," February 20,2004
3. EPRI Technical Report 1003557, BWRVIP-108: BWR Vessel and Internals Project, Technical Basis for the Reduction of Inspection Requirements for the Boiling Water Reactor Nozzle-to- Vessel Shell Welds and Nozzle Bend Radii, October 2002
4. Letter from the BWRVIP to the NRC (2002-323), Project No. 704 - BWRVIP-108:

BWR Vessel and Internals Project, Technical Basis for the Reduction of Inspection Requirements for the Boiling Water Reactor Nozzle-to- Vessel Shell Welds and Nozzle Bend Radii, November 25,2002 (ADAMS Accession No. ML023330203)

5. Letter from TVA to the NRC, Browns Ferry Nuclear Plant (BFN) - Units 2 and 3-American Society of Mechanical Engineers (ASME)Section XI, Inservice Inspection (lSI) Program - Requests for Relief 2-ISI-22, and 3-ISI-18 for Examination of Reactor Pressure Vessel (RPV) Nozzle-to- Vessel Shell Welds and Nozzle Inner Radius Sections - Response to NRC request for Additional Information (RAI) (TAC Nos. MC0167 and MC0168), November 15, 2004 (ADAMS Accession No. ML043380321 )
6. Letter from the BWRVIP to the NRC (2006-349), Project 704 - BWRVIP Response to NRC Request for Additional Information on BWRVIP-108, July 25, 2006 (ADAMS Accession No. ML062080159)
7. Letter from the BWRVIP to the NRC (2007-268), Project 704 - Supplemental Analyses Supporting BWRVIP-108, September 13,2007 (ADAMS Accession No. ML072600167)
8. Letter from the NRC to the BWRVIP, Safety Evaluation of Proprietary EPRI Report, "BWR Vessel and Internals Project, Technical Basis for the Reduction of Inspection Requirements for the Boiling Water Reactor Nozzle-to-Vessel Shell Welds and Nozzle Inner Radius (BWRVIP- 108)," December 19,2007 (ADAMS Accession No. ML073600374)
9. GGNS Calculation MC-Q1 B13-1 0002, Reduction of Inspection Requirements on Recirculation Inlet and Outlet Nozzles, Rev. O.

ATTACHMENT 2 GNRO-2011/00009 RESPONSES TO BWRVIP-108 PLANT-SPECIFIC APPLICABILITY CRITERIA to GNRO-2011/00009 Page 1 of 3 RESPONSES TO BWRVIP-108 PLANT-SPECIFIC APPLICABILITY CRITERIA Section 5 of the NRC's Safety Evaluation Report (SER) that approved the use of BWRVIP-108 states in part:

"Licensees who plan to request relief from the ASME Code,Section XI requirements for RPV nozzle-to-vessel shell welds and nozzle inner radius sections may reference the BWRVIP-108 report as the technical basis for the use of ASME Code Case N-702 as an alternative. However, each licensee should demonstrate the plant-specific application of the BWRVI P-1 08 report to their units in the relief request by showing that all the following general and nozzle-specific criteria are satisfied:"

Grand Gulf Nuclear Station (GGNS) applicability was evaluated and demonstrated as documented in GGNS Calculation MC-Q1 B13-1 0002, Reduction of Inspection Requirements on Recirculation Inlet and Outlet Nozzles, Rev. O. This demonstration is summarized below.

Applicable GGNS Terms and Parameters

  • RPV constant for inlet nozzle, CNozzle3 = 1,637 psi
  • RPV constant for outlet nozzle, CRPV4 = 16,171 psi
  • RPV constant for outlet nozzle, CNozzle5 = 1,977 psi
  • Reactor core pressure = 1,056 psig or 1,070.696 psia
  • Maximum RPV radius = 126.75 inches
  • RPV wall thickness at Nozzle N2, t2 = 7.4479 [(AvgLong + AvgTrans) 12]
  • RPV wall thickness at Nozzle N1, t4 = 7.4948 inches [(AvgLong + AvgTrans) 12]
  • Nozzle inner radius for outlet nozzles, rj = 10.84375 inches
  • Nozzle outer radius for outlet nozzles, ro =20.03125 inches
  • Nozzle inner radius for inlet nozzles, rj = 5.8125 inches
  • Nozzle outer radius for inlet nozzles, ro = 13.125 inches General Criterion Criterion 1 The maximum Reactor Pressure Vessel (RPV) Heat/Cool down rate is limited to less than 115°F/hour.

to GNRO-2011/00009 Page 2 of 3 GGNS Compliance Maximum heat up and cool down rates are limited to S 100°F in anyone-hour period, in accordance with GGNS Technical Specification SUNeillance Requirement 3.4.11.1.

Criteria for the Recirculation Inlet Nozzles

-=--_.:..- < 1.15 GGNS Compliance

--=:------'- = (1056 psi x 126.75 in) = 0.9296 < 1.15 19332(7.4479 in)

Criterion 3 GGNS Compliance 2 2 px(ro +ri ) _ (1056psi)x (13.125Y +(5.8125Y 2 2 0.9598 < 1.15 Cnozzle3 (ro - ri ) - 1637 (13.125Y (5.8125Y Criteria for the Recirculation Outlet Nozzles Criterion 4 (pxr) <1.15 C RPV4f4 GGNS Compliance (pxr) = (1056psixI26.75 in) =1.104<1.15 CRPV4f4 16171(7.4948)

Criterion 5 to GNRO-2011/00009 Page 3 of 3 GGNS Compliance p x (r,,' : r,'~ = 1056 psi x (20.031~5Y + (1O.843~5)' = 0.97698 < 1.15 Cnozzle5{rO -r 1 ) 1977 (20.03125) (10.84375)

The results of the above equations demonstrate the applicability of BWRVIP-1 08 to GGNS by showing the five criteria specified in Section 5 of the NRC SER are met.

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