ML20202E757
| ML20202E757 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 01/26/1999 |
| From: | Wharton L NRC (Affiliation Not Assigned) |
| To: | Gambhir S OMAHA PUBLIC POWER DISTRICT |
| References | |
| GL-97-01, GL-97-1, TAC-M98566, NUDOCS 9902030161 | |
| Download: ML20202E757 (5) | |
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 30666-0001 8
.. K... o January 26, 1999 5p-2W5 Mr. S. K. Gambhir Division Manager - Nuclear Operations Omaha Public Power District Fort Calhoun Station FC-2-4 Adm.
Post Office Box 399 Hwy. 75 - North of Fort Calhoun Fort Calhoun, Nebraska 68023-0399
SUBJECT:
GENERIC LETTER (GL) 97-01," DEGRADATION OF CRDM/CEDM NOZZLE AND OTHER VESSEL CLOSURE HEAD PENETRATIONS" RESPONSES FOR FORT CALHOUN STATION, UNIT NO.1 -(TAC NO. M 98566) AND THE COMBUSTION ENGINEERING OWNERS GROUP (CEOG) TOPICAL REPORT NO. CE NPSD-1085 Dear Mr. Gambhir.
On April 1,1997, the staff issued Generic Letter (GL) 97-01, " Degradation of CRDM/CEDM Nozzle and Other Vessel Closure Head Penetrations," to the industry requesting in part that addressees provide a description of the plans to inspect the vessel head penetration nozzles (VHPs) at their respective pressurized water reactor (PWR) designed plants. With respect to i
the issuance of the GL, the staff required the addressees to submit an initial response within 30 days of issuance informing the staff of the intent to comply with requested information and a follow-up response within 120 days of issuance containing the technical details to the staff's information requests. In the discussion section of the GL, the staff stated that " individual licensees may wish to determine their inspection activities based on an integrated industry inspection program..,," and indicated that it did not object to individual PWR licensees basing their inspection activities on an integrated industry inspection program.
As a result, the Combustion Engineering Owner's Group (CEOG) determined that it was appropriate for its members to develop a cooperative integrated inspection program in response to GL 97-01. The CEOG program documented in Topical Report No. CE NPSD-1085, "CEOG Response to NRC Generic Letter 97-01, Degradation of CEDM Nozzle and Other Vessel Closure Head Penetrations," was prepared by ABB Combustion Engineering Nuclear Operations (ABB-CE) on behalf of the CEOG and the following CEOG member utilities and plants:
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Arizona Public Service - Palo Verde Units 1,2, and 3 Baltimore Gas and Electric Company - Calvert Cliffs Units 1 and 2 Consumers Energy-Palisades Entergy Operations, Inc. - Arkansas Nuclear One Unit 2 and Waterford Unit 3 Florida Power and Light Company - St. Lucie Units 1 and 2
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Northeast Utilities - Millstone Unit 2
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Maine Yankee Atomic Power Company - Maine Yankee Nuclear Plant 9
Omaha Public Power District - Fort Calhoun Unit 1 Southern California Edison Company - San Onofre Units 2 and 3 9902030161 99012'6 PDR ADOCK 05000285 I
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Mr. S. K. Gambhir January 26, 1999 l
The CEOG submitted its integrated program and Topical Report CE NPSD-1085 to the staff on July 25,1997.
The staff has determined by letters dated April 30,1997, and July 30,1997, that you were a member of the CEOG and a participant in the CEOG integrated program that was developed to address the staff's requests in GL 97-01. In your letters, you also indicated that the information in Topical Report CE NPSD-1085 is applicable with respect to the assessment of VHP nozzles at the Fort Calhoun Station.
The staff has reviewed your responses to GL 97-01, dated April 30,1997 and July 30,1997, and requires the information identified in the enclosure to complete its review of the responses as they relate to the CEOG's integrated program for assessing VHP nozzles at CEOG member plants, and to the contents of Topical Report No. CE NPSD-1085. The staff requests a j
response to the request for additional information (RAl) within 90 days of the date of this letter.
I It should be noted that similar staff requests have been issued to other CEOG member utilities.
As was the staffe position before, the staff encourages you to address these inquiries in integrated fashion with the CEOG; however, the staff also requests that you identify any deviations from the CEOG's integrated program that may be specific to the Fort Calhoun Station. The staff appreciates the efforts expended with respect to this matter.
Sincerely, Original Signed By L. Raynard Wharton, Project Manager Project Directorate IV-2 Division of Reactor Projects -Ill/lV Office of Nuclear Reactor Regulation Docket No. 50-285 DISTRIBUTION:
Docket KBrockman, Region IV
Enclosure:
Request for Additional PUBLIC BJohnson, Region IV information PDIV-2 Reading TSullivan EAdensam JHarrold cc w/enci: See next page WBateman RWharton EPeyton OGC ACRS DOCUMENT NAME: G:\\CALHOUN\\RAl98556 OFC
/2DIV-2 PDIV-2 i
NAME Nharton Ehey n
DATE 01/24/98 01C6/98 OFFICIAL RECORD COPY l
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h Mr. S. K. Gambhir 3-January 26, 1999 cc w/ encl:
Winston & Strawn Mr. S. K. Gambhir ATTN: Perry D. Robinson, Esq.
Division Manager - Nuclear Operations 1400 L Street, N.W.
Omaha Public Power District Washington, DC 20005-3502 Fort Calhoun Station FC-2-4 Adm.
I Post Office Box 399 Mr. Jack Jensen, Chairman Hwy. 75-North of Fort Calhoun Washington County Board Fort Calhoun, Nebraska 68023-0399 of Supervisors Blair, Nebraska 68008 l
Mr. Wayne Walker, Resident inspector U S. Nuclear Regulatory Commission Post Office Box 309 Fort Calhoun, Nebraska 68023 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission i
611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Ms. Cheryl Rodgers, LLRW Program Manager Environmental Protection Section Nebraska Department of Health j
301 Centennial Mall, South i
P.O. Box 95007 Lincoln, Nebraska 68509-5007 Mr. J. M. Solymossy Manager-Fort Calhoun Station Omaha Public Power District Fort Calhoun Station FC-1-1 Plant Post Office Box 399 Hwy. 75 - North of Fort Calhoun Fort Calhoun, Nebraska 68023 Mr. Mark T. Frans Manager-Nuclear Licensing Omaha Public Power District Fort Calhoun Station FC-2-4 Adm.
Post Office Box 399 Hwy. 75 - North of Fort Calhoun Fort Calhoun, Nebraska 68023-0399 i
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REQUEST FOR ADDITIONAL INFORMATION l
OMAHA PUBLIC POWER DISTRICT l-l' FORT CALHOUN STATION. UNIT NO.1 DOCKET NO. 50-285 GENERIC LETTER g7-01 t
i The ABB - Combustion Engineering Corporation's (ABB-CE's) methodology for predicting the susceptibility of vessel head penetration nozzles in the CEOG plant designs is provided in i
Section 2.4 of CE Topical Report No. CE NPSD-1085, which was submitted to the staff on l
July 25, igg 7. ABB-CE's methodology applies a probabilistic inspecUon timing model (PITM) to l
predict the probability of having a given Control Element Drive Mechanism (CEDM) penetration nozzle or in-core instrumentation (ICl) nozzle fail in service. With respect to the PITM model, the term " failure" does not refer to a compromise of the structural integrity of the reactor coolant l
pressure boundary, but rather that the presence of a non-throughwall flaw may require attention or repair.
Since that time, the s.taff has leamed informally that the CEOG has decided to change the methodology for evaluating the CRDM penetration nozzles in ABB-CE designed plants, and lately has adopted a CEDM penetration nozzle crack initiation and growth susceptibility model that has been developed by the Dominion Engineering Company. However, the CEOG has not submitted an addendum to its response of July 25,1997, informing the staff of its decision to 4
change the susceptibility model being adopted by the Owners Group member utilities. The staff j
requests the following information be provided with respect to content of your plant-specific i
response to GL g7-01, and its relationship to the CEOG integrated program for assessing the potential for CEDM penetration nozzles to undergo primary stress corrosion cracking (PWSCC) or intergranular attack (IGA):
- 1. Designate which crack r usceptibility model is being endorsed for the assessment of j
CEDM penetration nozzies the Fort Calhoun Station. Indicate how the susceptibility i
model being endorsed relates to the CEOG's integrated program for assessing the i
CEDM penetration nozzles at ABB-CE designed plants, and whether or not the design of the susceptibility model is consistent with the contents of Topical Report CE NPSD.
1085. If the ABB-CE's PITM modelis being endorsed for the assessment of CEDM l
penetration nozzles at Ft. Calhoun, address the items a. through e. that follow, if the L
Dominion Engineering susceptibility model is being endorsed for the assessment of CEDM penetration nozzles at your plant (s), address the items f. through I. that follow.
If the PITM models are beina endorsed for the assessment of your CEDM ser, aid;cri nozzles.
i a.
Provide an expanded discussion and additional details desenbing how the time-to-failure model in the PITM relates to the PITM's time-to-initiation model.
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2-In particular, include an expanded discussion of how the PITM model relates growth of postulated flaws to the time-to-initiation model, and how the two aspects relate to each other and to the probability of failure methodology.
b.
Provide the latest PITM susceptibility ranking of CEDM penetration nonles, and if applicable of the vessel head instrumentation nonles at Fort Calhoun relative to the rankings of those at the other CEOG member plants.
c.
Provide a description of how the PITM model for assessing postulated flaws in vessel head penetration nonies was bench-marked, and list and discuss the standards the models were bench-marked against.
i d.
Provide any additional information regarding how the model will be refined to allow -
the input of plant-specific inspection data into the model's analysis methodology.
e.
Describe how the variability in the product forms, material specifications, and heat treatments used to fabricate each CEDM penetration nonle at the CEOG member utilities are addressed in the PITM model.
If the susceotibility model developed by Dominion Enaineerina is beina endorsed for the assessment of your CEDM oenetration nozzles:
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f.
Provide a description of how the various product forms, material specifications, and heat treatments used to fabricate each CEDM penetration nonle at the CEOG member utilities are handled in the Dominion Engineering susceptibility model.
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g.
Provide' any additional information, if available, regarding how the model will be l
refined to allow the input of plant-specific inspection data into the model's analysis methodology.
l, h.
Describe how the Dominion Engineering crack initiation and crack growth models for assessing postulated flaws in vessel head penetration nonles were bench-marked, and a listing and discussion of the standards the models were bench-marked against.
i.
Provide the latest model susceptibility rankings of CEDM penetration nonles in CEOG member plants based on the results of the Dominion Engineering susceptibility model analyses of these CEDM and ICI nonles.
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