BVY 09-066, 10CFR50.55a(a)(3)(i) Inservice Inspection Program Request VY-ISI-014

10CFR50.55a(a)(3)(i) Inservice Inspection Program Request VY-ISI-014

ML093520390
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	12/14/2009
From:	Michael Colomb Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BVY 09-066, VY-ISI-014
Download: ML093520390 (11)

Text

b Entergy Nuclear Operations, Inc.

Vermont Yankee P.O. Box 0250 dEntergy 320 Governor Hunt Rd Vernon, VT 05354 Tel 802 257 7711 Michael J. Colomb Site Vice President BVY 09-066 December 14, 2009 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555

SUBJECT:

10CFR50.55a(a)(3)(i) Inservice Inspection Program Request VY-ISI-014 Vermont Yankee Nuclear Power Station Docket No. 50-271 License No. DPR-28

Dear Sir or Madam:

Section 50.55a of Title 10 of the Code of Federal Regulations requires that Inservice Inspection (ISI) of American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 piping be performed in accordance with Section Xl of the ASME Boiler and Pressure Vessel Code. Pursuant to 10 CFR 50.55a(a)(3)(i) Entergy Nuclear Operations, Inc. (ENO) hereby requests NRC approval of the alternative to ASME Section Xl, Sub Article IWB-2500 to allow reduced percentage requirements for nozzle to vessel weld and inner radius examinations. This alternative is requested for the fourth ten-year interval IS program at Vermont Yankee Nuclear Power Station (VY), which began on September 1, 2003.

Approval of request VY-ISI-014 would allow reduced examination requirements through application of ASME Code Case N-702. The NRC has provided a Safety Evaluation approving the generic technical basis and acceptability criteria for application of Code Case N-702, which ENO has followed as detailed in the attached request. ENO requests approval of this request by November 30, 2010. Attachment 1 contains the description and basis for the request and Attachment 2 lists the affected nozzle assemblies.

There are no new regulatory commitments being made in this submittal.

Should you have any questions concerning this submittal, please contact Mr. David Mannai at 802-451-3304.

Sincerely, MJC/PLCA7

BVY 09-066 / Page 2 of 2 Attachments: 1. 10CFR50.55a(a)(3)(i) Inservice Inspection Program Request VY-ISI-014

2. Nozzle-to-Vessel Shell Welds and Nozzle Blend Radii Component Tables cc: Mr. Samuel J. Collins Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. James S. Kim, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 08C2A Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Rd.

Vernon, Vermont 05354 Mr. David O'Brien, Commissioner VT Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601

BVY 09-066 Docket No. 50-271 Attachment 1 Vermont Yankee Nuclear Power Station 10CFR50.55a(a)(3)(i) Inservice Inspection Program Request VY-ISI-014

BVY 09-066 / Attachment 1 / Page 1 of 5 Entergy Nuclear Operations, Inc Vermont Yankee Nuclear Power Station Request for Alternative In Accordance with 10 CFR 50.55a(a)(3)(i)

VY-ISI-01 4

1. ASME Code Component(s) Affected Code Class: 1 Component Numbers: N1, N2, N3, N5, N6, N7, N8, N9, N10 ( See Attachment 1 for detailed list of components)

Code

References:

(1) ASME Section Xl, 1998 Edition with 2000 Addenda (2) Code Case N-702 Examination Category: B-D (Inspection Program B)

Item Number: B3.90 and B3.100 Unit/Inspection Interval Vermont Yankee /Fourth (4th)10-year interval September Applicability: 2003 - August 2013

2. Applicable Code Requirement

ASME Section XI, 1998 Edition with 2000 Addenda Table IWB-2500-1, Examination Category B-D, Full Penetration Welds of Nozzles in Vessels - Inspection Program B requires a volumetric examination of all nozzles with full penetration welds to the vessel shell (or head) and integrally cast nozzles each 10-year interval. The subject components for this request for alternative consideration are the Reactor Vessel Nozzle-to-Vessel Welds (Item B3.90) and the Reactor Vessel Nozzle Inside Radii (Item B3.100).

3. Reason for Request

The twenty-five percent sampling level stated in Code Case N-702 (Reference 3) provides a significant reduction in worker dose exposure. Vermont Yankee Nuclear Power Station (VY) has estimated that the proposed reduction of inspection requirements would result in a reduction in worker dose exposure of approximately 8,000 mRem over the remainder of the current interval.

4. Proposed Alternative Pursuant to 10 CFR 50.55a(a)(3)(i), an alternative is requested from performing the required examinations on 100% of the identified nozzle assemblies in Attachment 2. As an alternative, incorporation of Code Case N-702 (Reference 3) would require examination of a minimum of 25% of the nozzle-to-vessel welds and inner radius sections, including at least one nozzle from each system and nominal pipe size. For each of the identified nozzle assemblies in Table 1, both the inner radius and the nozzle-to-shell weld would be examined. Six (6) nozzle assemblies remain to be inspected for the remainder of the interval. Table 1 summarizes the affected nozzle assemblies listed in Attachment 2.

BVY 09-066 / Attachment 1 / Page 2 of 5 Table 1 Minimum Total Number to be Group Number Examined Comments Recirculation 2 1 One to be examined in Period 3 Outlet (N1)

Recirculation Inlet 10 3 Five completed in Period 1 (N2)

Main Steam (N3) 4 1 Four completed in Period 2 Feedwater (N4) 4 4 Four completed in Period 2. Code Case excludes these nozzle examinations Core Spray (N5) 2 1 One completed in Period 2 Instrument (N6) 2 1 One to be examined in Period 2 Head Vent (N7) 1 1 To be examined in Period 3 Jet Pump 2 1 One to be examined in Period 3 Instrument (N8)

CRD Return Line 1 1 To be examined in Period 3. Code (N9) Case excludes this nozzle VY CRD Line is capped and as such is no longer the return for CRD.

Because N9 is a unique nozzle, it will be examined and an alternative is not being sought for this nozzle.

SBLC & Core DP 1 1 To be examined in Period 3 (N10)

The examination schedule proposed in this alternative request will result in the Interval 4 examination percentages shown below, thus satisfying the requirements of Table IWB-2412-1.

Period 1 Period 2 Period 3 ASME Cat. B-D I Examinations 10 20 10 Period Cumulative Percentage 25% 75% 100%

Code Case N-702 stipulates that VT-1 examination may be used in lieu of the volumetric examination for the inner radii (Item No. B3.100). Note that VY is not currently using Code Case N-648-1 on enhanced magnification visual examination and currently has no plans of using Code Case N-648-1 in the future. All examinations on Item 3.100, inner radius sections, will be volumetric examinations.

5. Basis for Proposed 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," (References 1 and 2) provides the basis for Code Case N-702. The evaluation found that failure probabilities

BVY 09-066 / Attachment 1 / Page 3 of 5 due to a Low Temperature Overpressure event at the nozzle blend radius region and nozzle-to-vessel shell weld are very low (i.e. < 1X 10-6 for 40 years) with or without inservice inspection.

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 by the BWRVIP via BWRVIP letter 2002-323 on November 25, 2002 and supplemented by Tennessee Valley Authority (TVA) letter dated November 15, 2004, and BWRVIP letters dated July 25, 2006, and September 13, 2007.

On December 19, 2007, the NRC issued a Safety Evaluation (SE) (Reference 4) approving the use of BWRVIP-1 08. Within Section 5 of the SE, it states that each licensee should demonstrate the plant-specific applicability of the BWRVIP-108 report to their units in the request for alternative by meeting the criteria discussed in Section 5 of the SE.

The applicability of the BWRVIP-108 report to VY is demonstrated by showing the criteria within Section 5 of the SE are met.

• The general terms used in the SE Section 5 applicability evaluations are:

CIRPV = recirculationinlet nozzles (from BWRVIP-108 model) = 19332 Psi Ci-NOZZLE = recirculationinlet nozzles (from BWRVIP- 108 model) = 1637 vsi Co-RPV= recirculationoutlet nozzles (from BWRVIP-108 model) = 16171 Psi CGoNOZZLE = recirculation outlet nozzles (from BWRVIP-108 model) = 1977 psi

• The VY nozzle-specific terms to be used in the SER Section 5 applicability evaluations are as follows:

Heatup/ Cooldown rate = 100 0F/hr p= Reactor Pressure Vessel (RPV) normal operatingpressure,P = 1010 psi r= RPV innerradius, r = 103" t= RPV wall thickness, t = 5.625" riN2 = inner radius for RecirculationInlet N2 nozzles, riN2 = 6.875" roN2 = outer radius for RecirculationInlet N2 nozzles, rON2 = 14. 125" rN1 = inner radius for RecirculationOutlet N1 nozzles, riNI = 12.875" roN1= outer radius for RecirculationOutlet N1 nozzles, roN1 = 24.375" Given the general and plant-specific terms, VY's conformance with the five (5) criteria is demonstrated as follows:

(1) Max RPV Heatup/Cooldown Rate Criterion - the maximum RPV heatup/cooldown rate is limited to < 11 50 F/hr In accordance with Technical Specification 3.6.A.2 Reactor Coolant System heatup and cooldown rates are limited to a maximum of 100°F when averaged over any one hour period and thus meets the requirement of criterion (1).

VY operating procedures limit the heatup rate to < 90°F/hr and cooldown rate to between 50°F/hr and 90°F/hr. This procedural guidance has satisfactorily maintained heatup/cooldown rates within the Technical Specification limits.

BVY 09-066 / Attachment 1 / Page 4 of 5 (2) Recirculation Inlet (N2) Nozzles Equation to meet criterion: (pr/t)/ Ci.RPV < 1.1 5

[(1010 psig)(103")/5.625"]/19332 = 0.96 < 1.15 The VY result is 0.96 and thus meets the requirement of criterion (2) to be < 1.15.

(3) Recirculation Inlet (N2) Nozzles Equation to meet criterion: [P(roN22 + riN2) + (rON2 2 - riN22 )J ÷ C.NOZZLE < 1. 15

[1010 psig ((14.13")2 + (6.88") 2)/((14.13")2 - (6.88") 2))]/1637 = 1.00 < 1.15 The VY result is 1.00 and thus meets the requirement of criterion (3) to be < 1.15.

(4) Recirculation Outlet (Ni) Nozzles Equation to meet criterion: (prtt)/Co-RPV < 1.15

[(1010 psig)(103")/5.625"]/16171 = 1.144 < 1.15 The VY result is 1.144 and thus meets the requirement of criterion (4) to be < 1.15.

(5) Recirculation Outlet (Ni) Nozzles 2 2 Equation to meet criterion: [P(roNl 2 + riN12) + (roN1 - riN1 )] + Co-NOZZLE < 1.15

[ 1010 psig ((24.38")2 + (12.88'"2) / ((24.38-)2 - (12.88") 2)] / 1977 = 0.906 < 1. 15 The VY result is 0.906 and thus meets the requirement of criterion (5) to be < 1.15 The results of the above equations demonstrate the applicability of the BWRVIP-108 report to VY by showing the criteria within Section 5 of the NRC SE are met. Therefore, the basis for using Code Case N-702 is demonstrated for VY.

6. Conclusion Use of ASME Code Case N-702 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 shell full penetration welds and nozzle inner radii sections identified in Attachment 1, Tables 1 and 2.

7. Duration of Proposed Alternative Upon approval by the NRC staff, this request for alternative will be utilized through the remainder of the VY Fourth Inspection Interval (September 1, 2003- August 31, 2013) for the nozzle assemblies listed in Attachment 1. The resubmittal of this request will occur as a part of an operating license renewal and new inspection interval. The use of Code Case N-702 is requested until such time as the ASME Code Case is published in a future revision of RG 1.147.

8. Precedents The NRC Staff has approved similar Requests for Alternative for the following plants:

1. Duane Arnold Energy Center, Docket No. 50-331, TAC No. MD8193/August 29, 2008

BVY 09-066 / Attachment 1 / Page 5 of 5

2. Perry Nuclear Power Plant, Docket No. 50-440, TAC No. MD8458/December 29, 2008

3. Columbia Generating Station, Docket No. 50-397, TAC No. MD9850/April 8, 2009

9. References

1. 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 Blend Radii," dated October 2002

2. BWRVIP letter 2002-323, Carl Terry, BWRVIP Chairman, to NRC Document Control Desk, "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 Blend Radii," November 25, 2002

3. 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 Xl, Division 1," dated February 20, 2004

4. Letter from Matthew A. Mitchell (NRR), to Rick Libra, BWRVIP Chairman, 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),"' dated December 19, 2007

BVY 09-066 Docket No. 50-271 Attachment 2 Vermont Yankee Nuclear Power Station Nozzle-to-Vessel Shell Welds and Nozzle Blend Radii Component Tables

BVY 09-066 / Attachment 2 / Page 1 of 2 Table 1 contains the nozzle assemblies that require nozzle-to-vessel weld examinations affected by this request. Table 2 contains the nozzle assemblies that require nozzle inner radius examinations affected by this request.

Table 1 Nozzle-to-Vessel Weld Examinations ASME Item Comp ID Item Description Status B3.90 N1A 28" Recirc Outlet Will be examined Period 3 B3.90 N1B 28" Recirc Outlet Requesting alternative to exam requirements B3.90 N2A 12" Recirc Inlet Examination complete Period 1 B3.90 N2B 12" Recirc Inlet Examination complete Period 1 B3.90 N2C 12" Recirc Inlet Examination complete Period 1 B3.90 N2D 12" Recirc Inlet Examination complete Period 1 B3.90 N2E 12" Recirc Inlet Examination complete Period 1 B3.90 N2F 12" Recirc Inlet Requesting alternative to exam requirements B3.90 N2G 12" Recirc Inlet Requesting alternative to exam requirements B3.90 N2H 12" Recirc Inlet Requesting alternative to exam requirements B3.90 N2J 12" Recirc Inlet Requesting alternative to exam requirements B3.90 N2K 12" Recirc Inlet Requesting alternative to exam requirements B3.90 N3A 18" Main Steam Examination complete Period 2 B3.90 N3B 18" Main Steam Examination complete Period 2 B3.90 N3C 18" Main Steam Examination complete Period 2 B3.90 N3D 18" Main Steam Examination complete Period 2 B3.90 N4A 10" Feedwater Examination complete Period 2 - Augmented B3.90 N4B 10" Feedwater Examination complete Period 2 - Augmented B3.90 N4C 10" Feedwater Examination complete Period 2 - Augmented B3.90 N4D 10" Feedwater Examination complete Period 2 - Augmented B3.90 N5A 8" Core Spray Examination complete Period 2 B3.90 N5B 8" Core Spray Requesting alternative to exam requirements B3.90 N6A 6" Instrument Will be examined Period 2 B3.90 N6B 6" Instrument Requesting alternative to exam requirements B3.90 N7 4" Head Vent Will be examined Period 3 B3.90 N8A 4" Jet Pump Will be examined Period 3 Instrument B3.90 N8B 4" Jet Pump Requesting alternative to exam requirements Instrument B3.90 N9 3" CRD Return Will be examined Period 3 Line VY CRD Line is capped and as such is no longer the return for CRD. Because N9 is a unique nozzle, it will be examined and an alternative is not being sought for this nozzle.

B3.90 N10 2" SBLC & Core Will be examined Period 3 DP

'I .. '.

BVY 09-066 / Attachment 2 / Page 2 of 2 Table 2 Nozzle Inner Radius Examinations ASME Item Comp ID Item Status Description B3.100 N1A-IR 28" Recirc Outlet Will be examined Period 3 B3.100 N1B-IR 28" Recirc Outlet Requesting alternative to exam requirements B3.100 N2A-IR 12" Recirc Inlet Examination complete Period 1 B3.100 N2B-IR 12" Recirc Inlet Examination complete Period 1 B3.100 N2C-IR 12" Recirc Inlet Examination complete Period 1 B3.100 N2D-IR 12" Recirc Inlet Examination complete Period 1 B3.100 N2E-IR 12" Recirc Inlet Examination complete Period 1 B3.100 N2F-IR 12" Recirc Inlet Requesting alternative to exam requirements B3.100 N2G-IR 12" Recirc Inlet Requesting alternative to exam requirements B3.100 N2H-IR 12" Recirc Inlet Requesting alternative to exam requirements B3.100 N2J-IR 12" Recirc Inlet Requesting alternative to exam requirements B3.100 N2K-IR 12" Recirc Inlet Requesting alternative to exam requirements B3.100 N3A-IR 18" Main Steam Examination complete Period 2 B3.100 N3B-IR 18" Main Steam Examination complete Period 2 B3.100 N3C-IR 18" Main Steam Examination complete Period 2 B3.100 N3D-IR 18" Main Steam Examination complete Period 2 B3.100 N4A-IR 10" Feedwater Examination complete Period 2 - Augmented B3.100 N4B-IR 10" Feedwater Examination complete Period 2 - Augmented B3.100 N4C-IR 10" Feedwater Examination complete Period 2 - Augmented B3.100 N4D-IR 10" Feedwater Examination complete Period 2 - Augmented B3.100 N5A-IR 8" Core Spray Examination complete Period 2 B3.100 N5B-IR 8" Core Spray Requesting alternative to exam requirements B3.100 N6A-IR 6" Instrument Will be examined Period 2 B3.100 N6B-IR 6" Instrument Requesting alternative to exam requirements B3.100 N7-IR 4" Head Vent Will be examined Period 3 B3.100 N8A-IR 4" Jet Pump Will be examined Period 3 Instrument B3.100 N8B-IR 4" Jet Pump Requesting alternative to exam requirements Instrument B3.100 N9-IR 3" CRD Return Will be examined Period 3 Line VY CRD Line is capped and as such is no longer the return for CRD. Because N9 is a unique nozzle, it will be examined and an alternative is not

_ _ _being sought for this nozzle.

B3.100 N10-IR 2" SBLC & Core Will be examined Period 3 DP