ML20207D426
| ML20207D426 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 02/25/1999 |
| From: | Dennis Morey SOUTHERN NUCLEAR OPERATING CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NEL-99-0052, NEL-99-52, NUDOCS 9903090338 | |
| Download: ML20207D426 (6) | |
Text
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r D ve Mozey S1uthern Nuclear' Vice President Operating Company i
Farley Project P.O. Rox 1295 i
Birmingham, Alabama 35201 Tel205 992 5131 k
t SOUTHERN h February'25, 1999 COMM EnergytoServehurWorld" Docket Nos.:
50-348 NEL-99-0052 50-364.
U. S. Nuclear Regulatory Commission ATfN: Document Control Desk Washington, D. C. 20555-0001
]
Joseph M. Farley Nuclear Plant Steam Generator Replacement Related ASME Section XI Relief Reauest No. RR-40 For The Stean Generator Primarv Nozzles Inside Radius Ladies and Gentlemen:
In accordance with the provisions of 10 CFR 50.55a(a)(3)(i), Southern Nuclear Operating Company (SNC) is requesting NRC approval of enclosed Relief Request No. RR-40 for Units 1 and 2. This relief request applies to both the current Westinghouse Model 51 steam generators and the planned replacement Westinghouse Model 54F ste:un Eenerators at Farley Nuclear Plant.
ASME Section XI requires a olumetric examination of the nozzle inside radius section of all steam generator primary side nozzle. Reliefis requested from performing the volumetric examination based on limited access, rough metal surfaces, and long metal paths. Detailedjustincation is provided in Enclosures 1 and 2.
SNC requests '4RC approval of the proposed relief request by March 4,2000 to support the Unit I steam generator replacement outage in the spring of 2000 and the Unit 2 steam generator replacement outage in the spring of 2001.
There are no new commitments contained in this letter. Ifyou have any questions, please advise.
Respectfully submitted, V
k$
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Dave Morey h0 CHM /maf: rr-40. doc Enclosures *
- 1. ' Relief Request RR Unit 1 I
2.'
Relief Request RR Unit 2 '
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i 990309033e 990225 ADOCK0500g38, OR
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l-Page 2 U. S. Nuclear Regulatory Commission L cc:
Southem Nuclear Oncratina Comoany 1
Mr. L. M. Stinson, General Manager - Farley 1f U. S. Nuclear Renulatory Commission. Washington. D. C.
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. Mr. J. I. Zimmerman, Licensing Project Manager - Farley J
U. S. Nuclear Regulatory Commission. Recion 11 Mr. L.- A. Reyes, Regional Administrator i
Mr. T. P. Johnson, Senior Resident inspector - Fnley -
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ENCLOSUREI Farley Nuclear Plant - Unit 1 l
Third Ten Year Interval Request for Relief No. RR-40 i
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NEI-99-0052 Southern Nuclear Operatmg Cn=tamny Farley Unit 1 Tiurd Ten Year Interval Request for ReliefNo. RR-40
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System / Component (s) for Which Reliefis Requested De nonle inside radius section of the l
pnmary side narrh of steam generators l
II.
Code Requirement Item No. B3.140, Category B-D, Table IWB-2500-1 of ASME Section XI, l
1989 Edition, no =Ma. requires a volumetric examination of the nonle inside radius section j
of all the steam generator primary side noules.
III.
Code Reauirernent for Which Reliefis Reauested: Reliefis requested from performing the l
volumetric examination of the nozzle inside radius section of the steam generator primary side nozzles.
I IV.
Basis for Rehef. The ASME Section XI Code Committee recognized that, based upon inspection 1
data and fracture mechanics evaluations, the steam generator nozzles are unlikely to crack under any anticipated service conditions. Extremely small probabilities of failure cause the benefit of J
l in-service inspection to be negligible. Further, these examinations are difficult to perform in-service because oflimited access, rough metal surfaces, and long metal paths. In most cases in-j service radiation dose levels are high.
i V.
Alternate Examination No examinations will be performed on these nozzle inside radius sections.
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i VI.
J=tib* ion for Grantine Relief: Code Case N419 has been approved and published by the ASME but has not yet been endorsed by the NRC in Regulatoiy Guide 1.147; therefore, SNC is requesting to apply Code Case N419 via this relief request. As part of the preparation of the code case, it was determined that after more than 25 years of plant operation and inspecions, the industry has found no cracking incidents or service-induced flaws of any kind in these nozzle inner radius sections. Fracture mechanics evaluations, based on conservative assumptions, demonstrated that these nozzles have a large tolerance for flaws. Probabilistic risk assessment calculations, with and without in-service inspection, gave such small probabilities of failure that any gain from inspection is meaningless.
Based on industry inspection results, fracture mechanics evaluations, and probabilistic risk assessment calculations, the ASME Section XI Code Committee determined that structumi integrity of these nozzles would not be reduced. SNC agrees with the code committee and believes that an =~~*=ble level of quality and safety can be maintained without inspecting these nonic inside radius sections in-service. Derefore, the climination of the inspections of these nozzle inside radius sections is justified per 10 CFR 50.55a(3)(i).
VII.
Implementation Schedule His request for reliefis applicable to examinations performed using the 1989 Edition of Section XI during the current inspection interval.
VIII.
Rehef Request Status AwaitingNRC approval.
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ENCLOSURE 2 Farley Nuclear Plant - Unit 2 Updated Program Request for Relief No. RR-40 i
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NEL-99-0052 Southern Nuclear Operating Company Farley Unit 2 Updated Program Request for ReliefNo. RR-40 1.
System /Comoonent(s) for Which Reliefis Reauested: The nozzle inside radius section of the primary side nozzles of steam generators.
II.
Code Reauirement: Item No. B3.140, Category B-D, Table IWB-2500-1 of ASME Section XI, 1989 Edition, no addenda, requires a volumetric examination of the nozzle inside radius section of all the steam generator pimary side nozzles.
III.
Code Reauirement for Which Reliefis Reauested: Reliefis requested from perfonning the volumetric examination of the nozzle inside radius section of the steam generator primary side nozzles.
l IV.
Basis for Relief: The ASME Section XI Code Committee recognized that, based upon inspection i
data ad fracture mechanics evaluations, the steam generator nozzles are unlikely to crack under any anucipated service conditions. Extremely small probabilities of failure cause the benefit of i
in-service inspection to be negligible. Further, these examinations are difficult to perform in-service because oflimited access, rough metal surfaces, and long metal paths. In most cases in-service radiation dose levels are high.
V.
Alternate Examination: No examinations will be performed on these nozzle inside radius sections.
VI.
Justification for Grantina Relief: Code Case N-619 has been approved and published by the ASME but has not yet been endorsed by the NRC in Regulatory Guide 1.147; therefore, SNC is requesting to apply Code Case N-619 via this relief request. As past of the preparation of the code case, it was determined that after more than 25 years of plant operation and inspections, the industry has found no cracking incidents or service-induced flaws of any kind in these nozzle inner radius sections. Fracture mechanics evaluations, based on conservative assumptions, i
I demonstrated that these nozzles have a large tolerance for flaws. Probabilistic risk assessment calculations, with and without in-service inspection, gave such small probabilities of failure that any gain from inspection is meaningless.
Based on industry inspection results, fracture mechanics evaluations, and probabilistic risk assessment calculations, the ASME Section XI Code Committee determined that structural 1
integrity of these nozzles would not be reduced. SNC agrees with the code committee and believes that an acceptable level of quality and safety can be maintained without inspecting these nozzle inside radius sections in-service. Therefore, the climination of the inspections of these nozzle ins'de radius sections is jusufied per 10 CFR 50.55a(3)(i).
i VII.
Imolementation Schedule: " Ibis request for reliefis applicable to examinations performed using the 1989 Edition of Sectics XI during the current inspection interval.
VIII.
Eg}ief Request Status: Awaiting NRC approval.