GO2-11-165, Response to Request for Additional Information License Renewal Application
| ML11285A046 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 10/06/2011 |
| From: | Swank D Energy Northwest |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GO2-11-165 | |
| Download: ML11285A046 (9) | |
Text
David A. Swank ENERGY Acting Vice President, Engineering P.O. Box 968, Mail Drop PE23 NORTHW ESTRichland, WA 99352-0968 Ph. 509-377-2309 F. 509-377-4173 daswank@ energy-northwest.com October 6, 2011 G02-11-165 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001
Subject:
COLUMBIA GENERATING STATION, DOCKET NO. 50-397 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION
References:
- 1) Letter, G02-1 0-11, dated January 19, 2010, WS Oxenford (Energy Northwest) to NRC, "License Renewal Application"
- 2) Letter dated February 3, 2011, NRC to SK Gambhir (Energy Northwest),
"Request for Additional Information for the Review of the Columbia Generating Station, License Renewal Application, for Metal Fatigue (TAC NO, ME3058" (ADAMS Accession No. ML110240426)"
- 3) Letter, G02-11-046, dated March 3, 2011, SK Gambhir (Energy Northwest to NRC, "Response to Request for Additional Information, License Renewal Application"
- 4) Letter dated February 3, 2011, NRC to Energy Northwest, "Summary of Telephone Conference Call held on January 20, 2011, Between the U.S.
Nuclear Regulatory Commission and Energy Northwest, Concerning the Request for Additional Information Pertaining to the Columbia Generating Station, License Renewal Application (TAC NO ME3058),"
Dear Sir or Madam:
By Reference 1, Energy Northwest requested the renewal of the Columbia Generating Station (Columbia) operating license.
A request for additional information (RAI) was transmitted to Energy Northwest via Reference 2. The initial analyses of additional locations for limiting cumulative usage factor (CUF) have been completed and are contained in the attachment to this letter.
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RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION Page 2 of 2 This letter also provides a change to LRA Table 4.3-5 to reflect a reduced CUF for the reactor recirculation systems loops based on updated information that General Electric Hitachi Nuclear Energy provided to Energy Northwest.
Transmitted herewith in the Attachment is the Energy Northwest response to the RAI contained in Reference 2. Enclosure 1 contains Amendment 45 to the Columbia LRA.
No new or revised commitments are included in this response.
If you have any questions or require additional information, please contact Abbas Mostala at (509) 377-4197.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the date of this letter.
Respe
'gully '
~ k 4DA Sw~anku.
Acting Vice President, Engineering
Attachment:
Response to Request for Additional Information
Enclosure:
License Renewal Application Amendment 45 cc:
NRC Region IV Administrator NRC NRR Project Manager NRC Senior Resident Inspector/988C EFSEC Manager RN Sherman - BPA/1399 WA Horin - Winston & Strawn AD Cunanan - NRC NRR (w/a)
BE Holian - NRC NRR RR Cowley - WDOH
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION Attachment Page 1 of 5 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION "Request for Additional Information for the Review of the Columbia Generating Station, License Renewal Application,"
(ADAMS Accession No. ML110240426)
RAI 4.3-09 Background and Issue:
In the response to RAI 4.3-06, dated November 11, 2010, the applicant provided the basis for not selecting the core shroud supports, main steam shell nozzles, and LPCI nozzle thermal sleeves as additional environmentally-assisted fatigue analysis locations. The staff noted that the applicant's plant-specific configuration may contain additional locations (including but not limited to those provided in LRA Tables 4.3-3 and 4.3-5) that may need to be analyzed for the effects of the reactor coolant environment other than those identified in NUREG/CR-6260. This may include locations that are limiting or bounding for the applicant's particular plant-specific configuration, or that have calculated environmentally-adjusted CUF values that are greater than those calculated by the applicant for locations that correspond to those identified in NUREG/CR-6260.
Request:
Confirm and justify that the locations selected for environmentally assisted fatigue analyses in LRA Table 4.3-6 consists of the most limiting locations for the plant (beyond the generic components identified in the NUREG/CR-6260 guidance). If these locations are not bounding, clarify the locations that require an environmentally assisted fatigue analysis and the actions that will be taken for these additional locations. If the limiting location identified consists of nickel alloy, state whether the methodology used to perform the environmentally-assisted fatigue calculation for nickel alloy is consistent with NUREG/CR-6909. If not, justify the method chosen.
Response
The locations originally selected for environmentally assisted fatigue (EAF) analysis in the LRA Table 4.3-6 are based on the locations identified in NUREG/CR-6260 and do not necessarily contain the most limiting locations for the plant. Energy Northwest reviewed additional locations to ensure that the limiting locations are evaluated. These additional locations are in the attached Table 1.
The additional locations were selected based on the highest cumulative usage locations listed in LRA table 4.3-3 and 4.3-5, therefore providing assurance that the limiting fatigue usage locations in air would be evaluated for the impact of environment. This latest review and associated calculations looked at every class 1 system and included a variety of materials and locations as tabulated in tables 4.3-3 and 4.3-5; the results are included in Table 1. Some locations, as noted on Table 1, were not evaluated because there was a similar bounding location. For example, Reactor Feed Water (RFW) piping
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION Attachment Page 2 of 5 line B is bounded by RFW piping line A. Non wetted locations, such as those only exposed to dry steam, were not evaluated for EAF. Non wetted locations are in the upper reactor vessel above the water seal skirt and are only exposed to steam that has been dried by passing through the moisture separator and steam dryer.
Environmentally adjusted Cumulative Usage Factors (CUFs) for nickel-alloy components beyond the NUREG/CR-6260 required locations are calculated consistent with the methods of NUREG/CR-6909. Additionally, the NUREG/CR-6260 locations that were reported in Table 4.3-6 of the License Renewal Application (LRA) have been calculated consistent with the methods of NUREG/CR-6909 and are included for comparison as Table 2.
The 60-year Environmental Fatigue Usage (Uenv) has been calculated and shown to be less than 1.0 for all but four locations at this time. The four locations are: The High Pressure Core Spray (HPCS) nozzle safe end extension, the Reactor Pressure Vessel (RPV) head spray check valve, the HPCS inboard isolation check valve and the Low Pressure Core Spray (LPCS) inboard isolation check valve. The fatigue of these four locations is being managed such that either the environmentally-adjusted CUFs will be shown to be less than 1.0 using more refined analysis techniques or other specific corrective actions, such as material replacement, will be taken prior to exceeding a CUF of 1.0.
Energy Northwest is in the process of preparing more detailed analysis for the four locations with the goal of completing the analysis in late October, 2011. The expected result from the refined analysis is that all locations discussed in this RAI response will be shown to have environmentally-adjusted CUFs less than 1.0. LRA Table 4.3-6 will be updated at that time. This remains an open item for the SER.
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION Attachment Page 3 of 5 Table 1 Summary of 60 year Environmental Fatigue Usage (Uenv) of Components with high 40 year CUF from LRA tables 4.3-3 and 4.3-5.
LRA Table 4.3-3 CGSCo p n t
or 4.3-5 Specific Component 60-year Uair Fen 60-year Uenv or 43~~5SpecficMaterial Location Component Core DP Cell Stub Tube NiCrFe 0.218 2.259 0.494 0.00078 4.221 HPCS Core Spray Forging LAS 0.00076 2.455 0.005 Nozzle Safe End 0.151 9.152 Extension 0.013 1.737 CRD Return Nozzle Forging LAS 0.093 3.565 0.330 Safe End CS 0.162 2.527 0.410 MR1 = 2.4 FW Nozzle Forging LAS 0.0398 Max = 5.34 0.140 RHR/LPCI Nozzle Forging LAS 0.001 10.51 0.0103 RRC Inlet Nozzle Forging LAS 0.0351 4.363 0.153 RRC Outlet Nozzle Cladding SS 0.00487 12.902 0.063 Nozzle LAS Dry steam environment -
Vessel Head Spray No environmental effects Min' = 1.0 RFW Piping Line A CS 0.284 Max = 1.897 0.385 HFW Piping Line B CS Bounded by RFWPiping LIne RFW Line A Calculation Highest and lowest Fen for multiple load pairs
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION Attachment Page 4 of 5 LRA Table 4.3-3 CGS or 4.3-5 Specific Component 60-year Uair Fen 60-year Uenv Location Component Lc Ion RWCU Piping CS 0.164 Max =-4.266 0.193 ROIC Piping CS Dry steam environment -
R___CPipingCSNo environmental effects RPV Head Spray Piping CS 0.259 1.74 0.451 Dry steam environment -
RPV Vent to MS Piping CS No environmental effects RPV Level Condensing SS 0.245 2.547 0.624 Pot SLC Piping CS 0.424 Min' = 1:0 0.737
_1 Max = 1.74 RPV Head Spray Check Valve CS 1.26
>1.74
>2.19 HPCS/LPCS Check Valve CS 0.99
>1.74
>1.73
' Highest and lowest Fen for multiple load pairs
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION Attachment Page 5 of 5 Table 2 NUREG/CR-6260 generic locations from LRA Table 4.3-6 that are nickel alloy material. Uenv calculated using methodology consistent with NUREG/CR-6909 Columbia NUREG/CR-6260 plant-Material type 60-year Uair Fen 60-year Ueny generic locations specific Total locations Reactor vessel shell CRD stub Nickel Alloy 0.0365 1.924 0.070 and lower head tube Reactor vessel FW nozzle Min 2 = 1.90 feedwater nozzle safe end Nickel Alloy 0.000886 Max = 3.72 0.00268 Reactor Core spray line vessel nozzle reactor vessel nozzle safe end -
Event group 1 = 0.240 1.926 0.464 and associated Core Spray Event group 2 = 0.002 1
Class 1 piping (high pressure)
RHR/LPCI Event group 1 = 0.118 1.924 nozzles and nozzle safe Nickel Alloy Event group 2 = 0.050 1.924 0.323 associated Class 1 end piping 2 Multiple load pairs for this location
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION Enclosure Page 1 of 1 LICENSE RENEWAL APPLICATION AMENDMENT 45 Section Page RAI Number Number Number Table 4.3-5 4.3-11 Supplement
Columbia Generating Station License Renewal Application Technical Information Disposition:
The effects of aging on the intended functions of the reactor coolant pressure boundary piping and components will be adequately managed for the period of extended operation by the Fatigue Monitoring Program.
Table 4.3-5 CUFs for Reactor Pressure Boundary Piping and Piping Components System or Component Max CUF Reactor Feedwater Line A 0.250 Reactor Feedwater Line B 0.137 Reactor Feedwater / RWCU 0.588 Main Steam Line A 0.446 Main Steam Line B 0.7225 Main Steam Line C 0.222 Main Steam Line D 0.647 Main Steam Isolation Valves 0.0093 Reactor Recirculation Loop A o.85o Reactor Recirculation Loop B 0.920 Reactor Recirculation Isolation Valves 0.0036 Reactor Water Cleanup 0.152 High Pressure Core Spray 0.237 Low Pressure Core Spray 0.145 Residual Heat Removal 0.001 Reactor Core Isolation Cooling 0.487 Reactor Vessel Head Spray 0.209 Reactor Vessel Head Vent to Main Steam 0.940 Reactor Vessel Level Instrument Lines and Condensing Pots 0.49 Standby Liquid Control System 0.262 Head spray check valve 0.84 12 inch containment isolation valves (5) 0.6599 40.28-79 Time-Limited Aging Analyses Page 4.3-11 j,..ua.y-201
]Amendment 45