ML20151X406
| ML20151X406 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/14/1998 |
| From: | Clifford J NRC (Affiliation Not Assigned) |
| To: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| GL-97-01, GL-97-1, TAC-M98593, TAC-M98594, NUDOCS 9809170072 | |
| Download: ML20151X406 (5) | |
Text
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j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. enana annt
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September 14, 1998 Mr. Harold B. Ray Executive Vice President Southern California Edison Company San Onofre Nuclear Generating Station P. O. Box 128 San Clemente, California 92674-0128
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER 97-01," DEGRADATION OF CRDM/CEDM NOZZLE AND OTHER VESSEL CLOSURE HEAD PENETRATIONS" FOR SAN ONOFRE NUCLEAR GENERATING STATIONS UNITS 2 AND 3 (TAC NOS. M98593 AND M98594)
Dear Mr. Ray:
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 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 issuaw 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 is 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," which was prepared by ABB Combustion Engineering Nuclear Operations (ABB-CE) on behalf of the CEOG and the following CEOG member utilities and plants:
Arizona Public Service - Palo Verde Units 1,2, and 3 j(
Baltimore Gas and Electric Company - Calvert Cliffs Units 1 and 2 j
Consumers Energy-Palisades j
Entergy Operations, Inc. - Arkansa Nuclear One Unit 2 and Waterford Unit 3 Florida Power and Light Company - St. Lucie Units 1 and 2 7j k
Northeast Utilities - Millstone Unit 2 9
Maine Yankee Atomic Power Company - Maine Yankee Nuclear Plant Omaha Public Power District - Fort Calhoun Unit 1 Southem Califomia Edison Company - San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 9809170072 980914 PDR ADOCK 05000361 P
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Mr. Harold B. Ray 2-September 14, 1998 j
i The CEOG submitted its integrated program and Topical Report CE NPSD-1085 to the staff on July 25,1097.
l The staff has determined by letter dated August 6,1998, that you are a member of the CEOG i
and a participant in the CEOG integrated program that was developed to address the staffs requests in GL 97-01. In your letter, you also indicated that the information in Topical Report i
CE NPSD-1085 is applicable to SONGS Units 2 and 3 with respect to the assessment of VHP nozzles.
The staff has reviewed your 120 day response to GL 97-01, dated August 6,1998, and requires the information identified in the enclosure to complete its review of the responses as they relate I
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 response to the RAI i
within 90 days of the date of this letter. It should be noted that similar staff requests have been issued to other CEOG member utilities. As was the staffs 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 San Onofre Nuclear Generating Station, Units 2 and 3. The staff appreciates the efforts expended with respect to this matter.
Sincerely, Original Signed By
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L i
James W. Clifford, Senior Project Manager Project Directorate IV-2 Division of Reactor Projects lil/lV Office of Nuclear Reactor Regulation Docket Nos. 50-361 DISTRIBUTION:
and 50-362 Docket File PGwynn, RIV PUBLIC DKirsch, RIV WCFO
Enclosure:
Request for Additional PDIV-2 R/F..
TSullivan -
Information EAdensam JHarrold '
WBateman cc w/ encl: See next page JClifford EPeyton OGC ACRS DOCUMENT NAME:- SO98593.RAI To receive e copy of this document, Indicate in the box: "C" = Copy without enclosures *E" = Copy with enclosures *N" = No copy OFFICE PDIVr2/F]M PDIV-2/LA NAME JCliffpfd EPeyton W DATE 09/11 /98 09/M /98 OFFICIAL RECORD COPY L
i Mr. Harold B. Ray
-3 September 14, 1998
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cc w/ encl.
Mr. R. W. Krieger, Vice President Resident inspector / San Onofre NPS
)
Southern California Edison Company c/o U.S. Nuclear Regulatory Commission San Onofre Nuclear Generating Station Post Office Box 4329 P. O. Box 128 San Clemente, Califomia 92674 i
l San Clemente, Califomia 92674-0128 Mayor Chairman, Board of Supervisors City of San Clemente County of San Diego 100 Avenida Presidio
.j 1600 Pacific Highway, Room 335 San Clemente, Califomia 92672 l
San Diego, California 92101 Mr. Dwight E. Nunn, Vice President Alan R. Watts, Esq.
Southem California Edison Company i
Woodruff, Spradlin & Smart San Onofre Nuclear Generating Station 701 S. Parker St. No. 7000 P.O. Box 128 l
2 Orange, Califomia 92668-4702 San Clemente, Califomia 92674-0128 Mr. Sherwin Harris Resource Project Manager Public Utilities Department City of Riverside I
3900 Main Street Riverside, Califomia 92522 i
Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavilion 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Mr. Paul Schneringer San Onofre Liaison San Diego Gas & Electric Company P.O. Box 1831 San Diego, Califomia 92112 4150 Mr. Steve Hsu I
Radiologic Health Branch i
State Department of Health Services Post Office Box 942732 Sacramento, Califomia' 94234
. ~.. - -.
s l
e REQUEST FOR ADDITIONAL INFORMATION SOUTHERN CALIFORNIA EDISON COMPANY. ET AL.
SAN ONOFRE NUCLEAR GENEPATING STATION. UNITS 2 AND 3 DOCKET NOS. 50-361 AND 50-362 l
GENERIC LETTER 97-01 1
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 Section 2.4 of CE Tepical Report No. CE NPSD-1085, which was submitted to the staff on July 25,1997. ABB-CE's methodology applies a probabilistic inspection timing model (PITM) to 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 structuralintegrity of the reactor coolant pressure boundary, but rather that the presence of a non-throughwall flaw may require attention or repair.
Since that time, the staff 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 change the susceptibility model being adopted by the Owners Group member utilities. The staff I
requests the following information be provided with respect to content of your plant-specific l
response to GL 97-01, and its relationship to the CEOG integrated program for assessing the l
potential for CEDM penetration nozzles to undergo primary stress corrosion cracking (PWSCC) i or intergranular attack (IGA):
1.
Designate which crack susceptibility modelis being endorsed for the assessment l
of CEDM penetration nozzles at the San Onofre Nuclear Generating Station, i
Units 2 and 3 (SONGS). Indicate how the susceptibility model being endorsed relates to the CEOG's integrated program for assessing the 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 penetration nozzles at SONGS, address items a. through e. that follow.
I If the Dominion Engineering susceptibility modelis being endorsed for the assessment of CEDM penetration nozzles at SONGS, address the items f.
through I. that follow.
j If the PITM models are beina endorsed for the assessment of vour CEDM oenetration nozzles:
a.
Provide an expanded discussion and additional details describing how the time-to-failure model in the PITM relates to the PITM's time-to-e
4
.S.
2-m initiation model. In particular, include an expanded discussion of how the I
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 noules, and if applicable of the vessel head instrumentation nozzles at SONGS relative to the rar. kings of those at the other CEOG member i
plants.
c.
Provide a description of how the PITM model for assessing postulated flaws in vessel head penetration nozzles was bench-marked, and list and discuss the standards the models were bench-marked against.
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 nozzle at the CEOG member utilities are addressed in the PITM model.
?
if the suscentibility model develooed bv Dominion Enoineerina is beino endorsed for the assessment of your CEDM oenetration nnnlae:
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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 nozzle at the CEOG member utilities are handled in the l
Dominion Engineering susceptibility model.
\\
g.
Provide any additional information, if available, regarding how the model
.l will be refined to allow the input of plant-specific inspection data into the model's analysis methodology.
h.
Describe how the Dominion Engineering crack initiation and crack growth models for assessing postulated flaws in vessel head penetration nozzles I
were bench-marked, and a listing and discussion of the standards the models were bench-marked against.
i 1.
Provide the latest model susceptibility rankings of CEDM penetration nozzles in CEOG member plants based on the results of the Dominion Engineering susceptibility model analyses of theccs CEDM and ICI nozzles.
l l
.