NG-08-0135, Request for NRC Approval of Alternative to Nozzle to Vessel Weld and Inner Radius Examinations

Request for NRC Approval of Alternative to Nozzle to Vessel Weld and Inner Radius Examinations

ML080710428
Person / Time
Site:	Duane Arnold
Issue date:	02/28/2008
From:	Richard Anderson Duane Arnold
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NG-08-0135
Download: ML080710428 (12)

Text

FPL Energy Duane Arnold, LLC 3277 DAEC Road Palo, Iowa 52324 FPL Energy.

Duane Arnold Energy Center February 28, 2008 NG-08-0135 10 CFR 50.55a U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Duane Arnold Energy Center Docket 50-331 License No. DPR-49 Alternative to Nozzle to Vessel Weld and Inner Radius Examinations Pursuant to 10 CFR 50.55a(a)(3)( i), FPL Energy Duane Arnold, LLC, (hereafter, FPL Energy Duane Arnold) hereby requests NRC approval of the enclosed alternative from 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 of the Inservice Inspection Program for the Duane Arnold Energy Center (DAEC), which began on November 1, 2006.

FPL Energy Duane Arnold requests approval of this request by the end of February 2009.

This letter contains no new commitments nor revises any previous commitments.

If you have any questions, please contact Steve Catron at (319) 851-7234.

Richard L. Ander on Vice President, Duane Arnold Energy Center FPL Energy Duane Arnold, LLC Enclosures cc: Administrator, Region Ill, USNRC Project Manager, DAEC, USNRC Senior Resident Inspector, DAEC, USNRC

Enclosure 1 to NG-08-0135 Page 1 of 5 Enclosure 1 10 CFR 50.55a Request Number NDE-R013 Alternative to Nozzle to Vessel Weld and Inner Radius Examinations

Enclosure 1 to NG-08-0135 Page 2 of 5 10 CFR 50.55a Request Number NDE-R013 Alternative to Nozzle to Vessel Weld and Inner Radius Examinations Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(i) which provides an acceptable level of quality and safety ASME Code Component(s) Affected Code Class: 1 Component Numbers: N1, N2, N3, N5, N6, N7, N8, Nll, N12, and N16 Nozzles (see Enclosure 2 for specific nozzle identifications)

Examination Category: B-D Item Number: B3.90 and B3.100

==

Description:==

Alternative to Table IWB-2500-1 (Inspection Program B)

Applicable Code Edition and Addenda

The DAEC is currently in its fourth 10-year interval and is committed to the ASME Code Section Xl, 2001 Edition, 2003 Addenda. Additionally, for ultrasonic examinations,Section XI, Appendix VIII, "Performance Demonstration for Ultrasonic Examination Systems," of the 2001 Edition is implemented as required (and modified) by 10 CFR 50.55a(b)(2)(xv).

Applicable Code Requirement

Table IWB-2500-1 "Examination Category B-D, Full Penetration Welded Nozzle in Vessels - Inspection Program B" Class 1 nozzle-to-vessel weld and nozzle inner radii examination requirements are given in Item Number B3.90 "Nozzle-to-Vessel Welds" and B3.100 "Nozzle Inside Radius Section." The method of examination is volumetric. All nozzles with full penetration welds to the vessel shell (or head) and integrally cast nozzles are examined each interval. All of the nozzle assemblies identified in Enclosure 2 are full penetration welds.

Reason for Request

The identified nozzles (see Enclosure 2) are scheduled for examination prior to the end of the current inspection interval for the Duane Arnold Energy Center (DAEC).

The proposed alternative provides an acceptable level of quality and safety, and the reduction in scope could provide a dose savings of as much as 25.2 Rem over the remainder of the interval.

Enclosure 1 to NG-08-0135 Page 3 of 5 Proposed Alternative and Basis for Use Proposed Alternative:

Pursuant to 10 CFR 50.55a(a)(3)(i), relief is requested from performing the required examinations on 100% of the identified nozzle assemblies (see Enclosure 2). As an alternative, for all welds and inner radii except for the Recirculation Outlet welds, DAEC proposes to examine 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, in accordance with Code Case N-702. For the nozzle assemblies identified in Enclosure 2, this would mean one from each of the groups identified below:

Group Total Number to be Comments Number examined Recirculation 2 2 This group does not meet Outlet (N1) Criteria 4 of the NRC Safety Evaluation Report (SER)1 Recirculation 8 2 Four completed in Inlet (N2) Refueling Outage (RFO) 20 (2007)

Vessel 6 2 One scheduled in RFO Instrumentation 22 (2010) and one (N11, N12, scheduled in RFO 23 N16) (2012)

Core Spray 2 1 One completed in RFO (N5) 20 (2007)

Nozzles on 3 1 One scheduled in RFO Vessel Top 21 (2009)

Head (N6, N7)

Jet Pump (N8) 2 i One completed in RFO 20 (2007)

Main Steam 4 1 One scheduled in RFO (N3) 1 23(2012)

Footnote 1 - the RPV wall thickness was taken from the Form N-1 Data Sheet.

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 the DAEC is not currently using Code Case N-648-1 on enhanced magnification visual examination and has no plans of using Code Case N-648-1 in the future. Volumetric examinations of all inner radii will be completed.

Enclosure 1 to NG-08-0135 Page 4 of 5 Basis for Use:

Electric Power Research Institute (EPRI) Technical Report 1003557, "BWRVIP-108:

Boiling Water Reactor 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," provides the basis for Code Case N-702. The evaluation found that failure probabilities at the nozzle blend radius region and nozzle-to-vessel shell weld due to a Low Temperature Overpressure event are very low (i.e., <1 x 10-6 for 40 years) with or without inservice inspection. The report concludes that inspection of 25% of each nozzle type is technically justified.

This EPRI report received an NRC SER dated December 19, 2007. In the SER, Section 5.0 "Plant Specific Applicability" indicates that each licensee who plans to request relief from the ASME Code,Section XI requirements for RPV nozzle-to-vessel shell welds and nozzle inner radius sections may reference 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 applicability for the BWRVI P-1 08 report to its units in the relief request by showing that all the general and nozzle-specific criteria addressed below are satisfied (reference Enclosure 3):

(1) the maximum Reactor Pressure Vessel (RPV) heatup/cooldown rate is limited to less than 11 5°F per hour. The DAEC surveillance that monitors reactor vessel heatup/cooldown (Surveillance Test Procedure (STP) 3.4.9-01) limits the rate to less than or equal to 100°F/hr for Curve B and less than or equal to 20°F/hr for Curve A.

(2) For the Recirculation Inlet Nozzles the following criteria must be met:

a. (pr/t)/CRPv<1.15, the calculation for the DAEC N2 Nozzle results in 0.9748 which is less than 1.15

b. [p(ro 2 +ri 2 )/(ro 2-ri 2 )]/CNoZZLE<1.15, the calculation for the DAEC N2 Nozzle results in 1.0923 which is less than 1.15.

(3) For the Recirculation Outlet Nozzles the following criteria must be met:

a. (pr/t)/CRPv< 1.15, the calculation for the DAEC N1 Nozzle results in 1.17 which is higher than 1.15.

b. [p(ro 2 +ri 2 )/(ro 2-ri )]/CNozzLE<1.15, the calculation for the DAEC N1 Nozzle results in 0.87 which is less than 1.15.

Based upon the above information, all RPV nozzle-to-vessel shell welds and nozzle inner radii sections, with the exception of the Recirculation Outlet Nozzles, meet the criteria and therefore Code Case N-702 is applicable. However, the Recirculation Outlet Nozzles do not meet all of the criteria and Code Case N-702 would not be applied. See Enclosure 3 for details.

Therefore, use of Code Case N-702 provides an acceptable level of quality and safety pursuant to 10 CFR 50.55a(a)(3)(i) for all RPV nozzle-to-vessel shell welds and nozzle inner radii sections, with the exception of the Recirculation Outlet Nozzles.

Enclosure 1 to NG-08-0135 Page 5 of 5 Duration of Proposed Alternative The proposed alternative will be used for-the remaining portion of the fourth ten-year interval of the Inservice Inspection Program for DAEC.

Precedents None

Enclosure 2 to NG-08-0135 Page 1 of 4 Enclosure 2 Applicable Nozzles

Enclosure 2 to NG-08-0135 Page 2 of 4 Cat Item No. Summary No. Component ID Nozzle ID Dwg/ISO System Nominal Comments No. Pipe Dose Estimates Size B-D B3.90 9700 RRA-D001 N2A 1.2-22 SHT- RR 10' 5000 (PDI Exam 2007) 01 B-D B3.100 9800 RRA-DO01- 1.2-22 SHT- RR 10" INNER RAD 01 B-D B3.90 9900 RRB-DO01 N2B 1.2-22 SHT- RR 10' 5000 01 B-D B3.100 10000 RRB-DO01- 1.2-22 SHT- RR 10" INNER RAD 01 B-D B3.90 10100 RRC-DO01 N2C 1.2-22 SHT- RR 10' 5000 (PDI Exam 2007) 01 B-D B3.100 10200 RRC-DO01- 1.2-22 SHT- RR 10" INNER RAD 01 B-D B3.90 10300 RRD-DO01 N2D 1.2-22 SHT- RR 10' 5000 01 B-D B3.100 10400 RRD-D001- 1.2-22 SHT- RR 10" INNER RAD 01 B-D B3.90 10500 RRE-DO01 N2E 1.2-20 SHT- RR 10" 5000 (PDI Exam 2007) 01 B-D B3.100 10600 RRE-DO01- 1.2-20 SHT- RR 10" INNER RAD 01 B-D B3.90 10700 RRF-DO01 N2F 1.2-20 SHT- RR 10" 5000 01 B-D B3.100 10800 RRF-D001- 1.2-20 SHT- RR 10" INNER RAD 01 B-D B3.90 10900 RRG-D001 N2G 1.2-20 SHT- RR 10" 5000 (PDI Exam 2007) 01 B-D B3.100 11000 RRG-D001- 1.2-20 SHT- RR 10" INNER RAD 01 B-D B3.90 11100 RRH-DO01 N2H 1.2-20 SHT- RR 10' 5000 (PDI Exam 2007) 01 B-D B3.100 11200 RRH-D001- 1.2-20 SHT- RR 10' INNER RAD 01 B-D B3.90 11300 VIA-DO01 N11A 1.2-28 SHT- VI 2.5" 300 01 B-D B3.100 11400 VIA-DO01- 1.2-28 SHT- VI 2.5" INNER RAD 01 B-D B3.90 11500 VIB-DO01 N11B 1.2-29 SHT- VI 2.5" 300 (PDI Exam 2005) 01 B-D B3.100 11600 VIB-DO01- 1.2-29 SHT- VI 2.5" INNER RAD 01 B-D B3.90 11700 VIC-DOO1 N12A 1.2-30 SHT- VI 2.5" 400 01 B-D B3.100 11800 VIC-Do01- 1.2-30 SHT- VI 2.5" INNER RAD 01 B-D B3.90 11900 VID-DO01 N12B 1.2-31 SHT- VI 2.5" 400 01 B-D B3.100 12000 VID-DO01- 1.2-31 SHT- VI 2.5" INNER RAD 01 B-D B3.90 12100 VIE-DO01 N16A 1.2-33 SHT- Vl 2.5" 1000 01 B-D B3.100 12200 VIE-DO01- 1.2-33 SHT- VI 2.5" INNER RAD 01

Enclosure 2 to NG-08-0135 Page 3 of 4 Cat Item No. Summary No. Component ID Nozzle ID Dwg/ISO System Nominal Comments No. Pipe Dose Estimates Size B-D B3.90 12300 VIF-DO01 N16B 1.2-34 SHT- VI 2.5" 1000 01 B-D B3.100 12400 VIF-DO01- 1.2-34 SHT- VI 2.5" INNER RAD 01 B-D B3.90 4600 CRA-DO01 N9 1.2-12A CR 2.5" Cannot use for Code SHT-01 Case N-702 B-D B3.100 4700 CRA-DO01- 1.2-12A CR 2.5" Cannot use for Code INNER RAD SHT-01 Case N-702 B-D B3.90 4800 CSA-DO01 N5A 1.2-07 SHT- CS 8" 900 01 B-D B3.100 4900 CSA-DO01- 1.2-07 SHT- CS 8" INNER RAD 01 B-D B3.90 5000 CSB-DO01 N5B 1.2-08 SHT- CS 8" 900 (PDI Exam 2007) 01 B-D B3.100 5100 CSB-DO01- 1.2-08 SHT- CS 8" INNER RAD 01 B-D B3.90 5300 FWA-DO01 N4A 1.2-05 SHT- FW 10' Cannot use for Code 01 Case N-702 B-D B3.100 5400 FWA-DO01- 1.2-05 SHT- FW 10" Cannot use for Code INNER RAD 01 Case N-702 B-D B3.90 5800 FWB-DO01 N4B 1.2-05 SHT- FW 10" Cannot use for Code 01 Case N-702 B-D B3.100 5900 FWB-DO01- 1.2-05 SHT- FW 10" Cannot use for Code INNER RAD 01 Case N-702 B-D B3.90 6300 FWC-DO01 N4C 1.2-06 SHT- FW 10" Cannot use for Code 01 Case N-702 B-D B3.100 6400 FWC-DO01- 1.2-06 SHT- FW 10" Cannot use for Code INNER RAD 01 Case N-702 B-D B3.90 6800 FWD-DO01 N4D 1.2-06 SHT- FW 10" Cannot use for Code 01 Case N-702 B-D B3.100 6900 FWD-DO01- 1.2-06 SHT- FW 10" Cannot use for Code INNER RAD 01 Case N-702 B-D B3.90 7200 HDA-DO01 N15 1.2-32 SHT- HD 2" Exempt by IWB-01 1220(c)

B-D B3.100 7250 HDA-DO01- 1.2-32 SHT- HD 2" Exempt by IWB-INNER RAD 01 1220(c)

B-D B3.90 7300 HSB-DO01 N6B 1.2-23 SHT- HS 6" 01 B-D B3.100 7400 HSB-DO01- 1.2-23 SHT- HS 6" INNER RAD 01 B-D B3.90 7500 HVA-DO01 N7 1.2-24 SHT- HV 4" 01 B-D B3.100 7600 HVA-DO01- 1.2-24 SHT- HV 4" INNER RAD 01 B-D B3.90 9500 RHA-DO01 N6A 1.2-13 SHT- RH 6" 01 B-D B3.100 B 9600 RHA-DO01- 1.2-13 SHT- RH 6" INNER RAD 01

Enclosure 2 to NG-08-0135 Page 4 of 4 Cat Item No. Summary No. Component ID Nozzle ID Dwg/ISO System Nominal Comments No. Pipe Dose Estimates Size B-D B3.90 7700 JPA-DO01 N8A 1.2-25 SHT- JP 4" 1200 (PDI Exam 2007) 01 B-D B3.100 7800 JPA-DO01- 1.2-25 SHT- JP 4" INNER RAD 01 B-D B3.90 7900 JPB-D001 N8B 1.2-26 SHT- JP 4" 1200 (PDI Exam 2005) 01 B-D B3.100 8000 JPB-DOO1- 1.2-26 SHT- JP 4" INNER RAD 01 B-D B3.90 8100 LCA-DO01 N1O 1.2-27 SHT- LC 2" 400 (PDI Exam 2005) 01 B-D B3.100 8200 LCA-DO01- 1.2-27 SHT- LC 2" INNER RAD 01 B-D B3.90 8300 MSA-DO01 N3A 1.2-01 SHT- MS 20" 100 01 B-D B3.100 8400 MSA-DO01- 1.2-01 SHT- MS 20" INNER RAD 01 B-D B3.90 8500 MSB-DO01 N3B 1.2-02 SHT- MS 20" 100 01 B-D B3.100 8600 MSB-DO01- 1.2-02 SHT- MS 20" INNER RAD 01 B-D B3.90 8700 MSC-DO01 N3C 1.2-03 SHT- MS 20" 100 (PDI Exam 2005) 01 B-D B3.100 8800 MSC-DO01- 1.2-03 SHT- MS 20" INNER RAD 01 B-D B3.90 8900 MSD-DO01 N3D 1.2-04 SHT- MS 20" 100 (PDI Exam 2005) 01 B-D B3.100 9000 MSD-DO01- 1.2-04 SHT- MS 20" INNER RAD 01 B-D B3.90 9100 RCA-DOO1 N1A 1.2-19A RC 22" Does not meet Criteria SHT-01 4 of the NRC SER B-D B3.100 9200 RCA-DO01- 1.2-19A RC 22" Does not meet Criteria INNER RAD SHT-01 4 of the NRC SER B-D B3.90 9300 RCB-DO01 N1B 1.2-21A RC 22" Does not meet Criteria SHT-01 4 of the NRC SER B-D B3.100 9400 RCB-DOO1- 1.2-21A RC 22" Does not meet Criteria INNER RAD SHT-01 4 of the NRC SER

Enclosure 3 to NG-08-0135 Page 1 of 2 Enclosure 3 Responses to NRC Plant Specific Applicability

Enclosure 3 to NG-08-0135 Page 2 of 2 Responses to NRC Plant Specific Applicability 1 The maximum Reactor Pressure Vessel (RPV) heatup/cooldown rate is limited to less than 11 50 F/hour Response STP 3.4.9-01 limits the RPV heatup/cooldown to <100°F for Curve B and

<20'F for Curve A Recirculation Inlet Nozzles Recirculation Outlet Nozzles 2 (pr/t)/CRPv< 1.15 4 (pr/t)/CRPv<1.15 p=RPV Normal Operating Pressure 1025 p=RPV Normal Operating Pressure 1025 r=RPV inner radius 92.5 r=RPV inner radius 92.5 t=RPV wall thickness 5.031 t=RPV wall thickness 5.031 CRPV= 19332 CRPV- 16171 3 [p(ro 2 +ri 2 )/(ro 2-ri 2 )]/CNozzLE< 1.15 5 [p(ro 2 +ri 2 )/(ro2 -ri 2 )]/CNozzLE<1 .15 p=RPV Normal Operating Pressure 1025 p=RPV Normal Operating Pressure 1025 ro =nozzle outer radius 10.56 ro=nozzle outer radius 19.628 ri=nozzle inner radius 5.5 ri=nozzle inner radius 9.875 CNOZZLE 1637 CNO77LE 1977 1*!*.*3] <1.155