ML20199J725
| ML20199J725 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/20/1997 |
| From: | Fields M NRC (Affiliation Not Assigned) |
| To: | Nunn D SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| TAC-M99558, TAC-M99559, NUDOCS 9711280208 | |
| Download: ML20199J725 (6) | |
Text
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i November 20,.1997
^
Mr. Owight E. Nunn Vice President Southern California Edison Company San Onofre Nuclear Generating Station P. 0 Box 128 San Clemente. California 92674-0128
SUBJECT:
MECHANICAL N0ZZLE SEAL ASSEMBLY CODE RE._ACEMENT FOR SAN ON0FRE NUCLEAR GENERATING STATION. UNITS 2 AND 3 - REQUEST FOR ADDITIONAL INFORMATION (TAC NOS M99558 AND M99559) i
Dear Mr. Nunn:
s
' ByLletterdatedJuly 11, 1997. Southern California Edison requested NRC approval-to use the mechanical nozzle seal assembly as an alternate ASME Code replacement at the San Onofre Nuclear Generating Station. Units 2 and 3.
1 4
I After its review of the July 11 letter, the NRC has determined that additional information is required to compiete its evaluation of this proposal.
Enclosed is the additional i:1 formation required.
If there are any questions regarding
'this request, please call me at (301) 415-3062.
Sincerely, Original Signed By Mel B. Fields Project Manager Project Directorate IV-2 Division of Reactor Projects III/lk Office of Nuclear Reactor Regulation Docket Nos. 50-361 DISTRIBUTION:
and 50-362 TDocket& File PUBLIC
Enclosure:
Request for Additional PDIV-2 Reading
,f,i Information EGA1 WBatt-cc w/ encl:
See next page MFielos EPeyton OGC, 015B18
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DATE 11 M 7 11@ 4 97 0FFICIAL RECORD COPY 9711290200 971120 PDR ADOCK 05000361 P
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Mr. Dwight E. Nunn
-2 November 20, 1997 ct w/ enc 1:
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. California 92674 San Clemente. California 92674-0128 Mayor Chairman. Board of Supervisors City of San Clemente County of San Diego 100 Avenida Presidio 1600 Pacific Highway. Room 335 San Clemente. California 92672 San Diego, California 92101 Mr. Harold B. Ray Alan R. Watts. Esq.
Executive Vice President Woodruff. Spradlin & Smart Southern California Edison Company 701 S. Parker St. No. 7000 San Onofre Nuclear Generating Station Orange, California 92668-4702 P.O. Box 128 San Clemente, California 92674-0128 Mr. Sherwin Harris Resource Project Manager Public Utilities Department City of Riverside 3900 Main Street Riverside. California 32522 Dr. Harvey Collins, Chief Division of Drinking Water and Environmental Management California Department of Health Services P. O. Box 942732 Sacramento, California 94234-7320 4
Regional Administrator Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavilion 611 Ryan Plaza Drive. Suite 400 Arlington,. Texas 76011-8064 Mr. Terry Winter Manager, Power 03erations San Diego Gas & Electric Company P.O. Box 1911 San Diego, Cc'ifornia 92112-4150 Mr. Steve Hsu Radiologic Health Branch State Department of Health Services Post Office Box 942732 Sacramento. California 94234 l
d t o-REQUEST FOR ADDIT!0NAL INFORMATION SAN ONOFRE NUCLEAR GENERATING STATIOND UNIT NOS. 2 AND 3 DOCKET NOS. 50-361 AND 50 362 i
REOUEST FOR RELIEF ~FROM 10 CFR S0.55a MECHANICAL N0Z2LE SEAL ASSEMBLY ~ CODE REPLACEMENT o
The following items correspond to the sections ~1n the enclosure to the licensee's. letter of July 11. 1997.
BACKGROUND
- Provide the total number of proposed replacement instrument nozzles and their detailed location on the reactor coolant system (RCS) hot leg and the
- pressurizer.
DESCRIPT10N' 1.
. Provide a detailed listing of all instrument nozzles on the RCS hot leg and the' pressurizer where the "J" welds leaked.' and the repair and inspection procedures of each weld.
Provide the results of metallurgical exam 1 nations showing that the cracks were caused by stress corrosion cracking.
2.
Provide a detailed listing of all events where a "J" weld cracked completely and the_ instrument nozzle was ejected.
Provide the results of the metallurgical examinations of these welds. State the date when the nozzles were last inspected prior to the occurrence of each event, and the repair procedures which were followed in each case.
State if these events were reported to the NRC.
3.
At each nozzle location.' provide the latest results of the irservice inspection, and the dt.te when performed.
4.
-Provide all dimensions and the materials of all comporents shown in Figures 2 through 7.
~
DEGRADATION MECHAN 1SMS CONSIDERED a.
-Erosion / corrosion of Low Alloy Steel Components Provide your basis for: stating that the boric acid will not be replenished, thereby limiting corrosion of the carbon steel.
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b.
"J_" Weld Cracking Provide a summary of the testing performed and its results.
c.
Grafoil Seal Corrosion
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2 If there is a crack in the "J" weld, the annulus will be filled with water and the seal will then be continuously in contact with the water. State why the galvanic corrosion will stop in the presence of this water.
Provide test data to support this assertion. Also, provide test data showing performance of the seal material considering thermal cycling and environmental effects.
d.
Hardware Corrosion The fasteners in this application are made from SA-453. Grade 660 (A-286).
Since the fasteners may be wetted by leakace past the seal, provide test data on the performance of this alloy from a corrosion perspective. Address the effects of oxygen and chloride concentration on stress corrosion cracking performance.
Define the expected environmental conditions. including measures at the plant to limit chloride contamination.
CONFORMANCE TO ASME CODE 1.
DESIGN AND FABRICATION Provide the ABB CE design report for the mechanical nozzle seal assembly (MNSA) showing compliance with the ASME Section III Code.
1.4 NB-3600 Compliance:
NB-3671.1 Qualification Program Test Program 1.
Provide the details of the three MNSA test configurations.
State whether the tests of the MNSA were performed with the RTDs and the attached tubing in place.
2.
Provide the design thermal and mechanical 03erating and transient cycling loading conditions that t1e MNSAs are expected to experience during the life of the plant.
3.
Show that the fatigue tests envelope all expected operating and transient conditions for the life of the plant.
4 Provide details abo A the seismic shake tests. These tests were performed in tre cold condition.
State why they are applicable to seismic shaking in the hot condition.
l a
N TEST PROGRAM RESULTS 1.
Prevention of SeDaration of the Joint Under all Serm Conditions 1.1 Sumary of Results 1.
Provide a sumary of the test results.
2.
Provide the details of tne special effects test with the simulated 360* crack.
State the pressure et which the nozzle slipped and contacted the anti-ejection device.
1.2 Conclusion Concernit.g Joint Separation Provide the test re!,ults demonstrating that the joint is capable of maintaining both mechanical and seal integrity under all service conditions, for the life of the plant.
2.
Accessibility for Maintenance. Removal and Reolacement, 2.1 Description State what steps will be taken to prevent the potential ejection of a nozzle wtiile installing a MNSA without complete depressurization or draining below the nozzle in question.
3.
Demonstration of Safety of the Joint Under Service Conditions 3.2 Analytical Verification Provide the analysis of the MNSA showing that all components are within allowable stresses.
4.
Joint Desian Comoliance with NB-3200 4.2 Conclusion. Safety of Joint 1.
Provide ABB Document Number S-PENG-DR-003. " Addendum to the Piping Analytical Stress Report for SCE SONGS Units 2 and 3."
2.
Provide ABB Docuraent Number S-PENG-DR-002. " Addendum to the Pressurizer Analytical Stress Report for SCE SONGS Units 2 and 3."
3.
Provide the results of the ASME Section III NB-3200 fatigue the bolt holes, pressurizer wall and the hot leg wall, with analysis of the i
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Insoection z
-1.
Describe the procedure to inspect for leakage from a through-.
wall crack in the nozzle.
2.
Provide the inspection method to verify that no icss of preload will occur.-
3.
Since the-fasteners are susceptible to' stress corrotion cracking, provide your rationale-for not-performing volumetric examination of the fasteners.
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