ML13333A625
| ML13333A625 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/10/1987 |
| From: | Medford M SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8712150392 | |
| Download: ML13333A625 (16) | |
Text
Southern California Edison Company P. O. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M. 0. MEDFORD TELEPHONE MANAGER OF NUCLEAR ENGINEERING (818) 302-1749 AND LICENSING December 10, 1987 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Subject:
Docket No. 50-206 Standby Diesel Generators San Onofre Nuclear Generating Station Unit 1
References:
(A) Letter from R. F. Dudley (NRC) to K. P. Baskin (SCE), dated May 27, 1986, Transamerica-Delaval (TDI) Diesel Engine Reliability and Operability (B) Letter from M. 0. Medford (SCE) to G. E. Lear (NRC), dated June 20, 1986, Revised TDI Diesel Generators M/S Program (C) Letter from M. 0. Medford (SCE) to G.E. Lear (NRC), dated May 19, 1986, Inspection Report on Emergency Diesel Generator No. I (D) Letter from M. 0. Medford (SCE) to G.E. Lear (NRC), dated June 20, 1986, Inspection Report on Emergency Diesel Generator No. 2 (E) Letter from M. 0. Medford (SCE) to G.E. Lear (NRC), dated July 21, 1986, Supplemental Inspection Report on Emergency Diesel Generator No. I (F) Letter from M. 0. Medford (SCE) to Document Control Desk (NRC), dated July 9, 1987, Standby Diesel Generators (G) Letter from M. 0. Medford (SCE) to J. A. Zwolinski (NRC),
dated September 3, 1985, TDI Diesel Engines Design Review and Quality Revalidation Report This letter is in response to Reference A which requested that Southern California Edison (SCE) provide a detailed report on the status and implementation dates and/or schedules for all TDI Diesel Generator Owners 6712150392 871210 PDR ADOCK 05000206 PDR
Document Control Desk December 10, 1987 Group Phase 1 and Phase 2 recommendations for quality revalidation inspection and component replacement or modification pertaining to the San Onofre Unit 1 standby diesel generators.
The recommendations described above are contained in their entirety in Appendix I of the Owners Group Design Review and Quality Revalidation (DR/QR) report for the San Onofre Nuclear Generating Station. However, Appendix I also lists a large number of recommendations that deal with maintenance and surveillance (M&S) rather than quality revalidation inspection or component modification/replacement. These M&S items are beyond the scope of the NRC's request.
For these M&S items, subject to one clarification provided with Reference B and two further clarifications noted in the enclosed Table A for component numbers 02-415A and 02-8058, SCE is implementing Appendix II of the DR/QR report, as previously committed.
On the subject of quality revalidation inspections, a concerted effort was made by SCE to implement all of these inspections during the 1985-86 San Onofre Unit 1 refueling outage. Detailed reports on these inspections and associated corrective actions have been previously submitted to the NRC by References C, D and E.
Earlier this year, SCE performed a comprehensive review to document implementation of all of the Owners Group Phase 1 and Phase 2 recommendations relating to quality revalidation inspection and component replacement or modification. The enclosed Table A is a summary of those cases where a deviation was found to exist or where a clarifying comment is appropriate.
For each case that represents a deviation, Table A provides appropriate justification for the deviation or proposed corrective action and schedule for the corrective action. This approach is consistent with the following statements in Section 5.0 of the DR/QR report:
"These recommendations represent a conservative approach to insuring diesel generator reliability, and in accordance with the intent of the Owners Group Program Plan, it is anticipated that these recommendations will be incorporated subsequent to commercial plant operation but prior to restart from the first plant refueling outage. In some cases, the utility may propose alternate means of insuring the reliability of their emergency diesel engines.
Justification of these alternate means is the responsibility of the utility."
Document Control Desk December 10, 1987 All recommendations not identified in Table A have been implemented.
If you have any questions regarding this submittal, please let me know.
Sincerely, Enclosure cc: J. 0. Bradfute, NRR Project Manager San Onofre Unit 1 J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3 S. E. Eckert, Duke Engineering & Services, Inc.
TABLE A COMMENTS ON SELECTED DR/QR REPORT RECOMMENDATIONS Component No. Component Description Recommendation Comment 02-311A Crankcase: Crankcase Verify material of This verification will be performed Assembly crankcase based on by the end of Cycle X refueling foundry records.
outage.
02-315D Water Manifold: Jacket For seismic considerations, Inaccessible piping has not Water Manifold and it is recommended that been inspected. This inspection Piping inaccessible piping be will be completed if a disassembly inspected to ensure permitting access is performed in adequate seismic restraint.
the future.
02-316A&B Jacket Water Inlet Same as for No. 02-315D Same as for No. 02-3150 Manifold: Manifold above.
above.
Assembly with Hardware and Coupling and Gaskets 02-315E Cylinder Block Liners and Lubricate cylinder head In accordance with Section 6A2 Water Manifold: Studs stud blockside threads of Vol. I of TDI Technical Manual, with engine oil.
the lubricant used was a 50/50 mixture of engine oil and graphite.
Verify proper torque loads This verification has not been were applied by a review performed by SCE. Review of of existing documentation.
existing TDI documentation and verification of proper torque loads will be completed by the end of the next disassembly of these components.
02-315G Cylinder Block Liners Per TDI SIM 315, verify There is no requirement to remove and Water Manifold:
that proper cylinder the cylinder liners prior to the Seals & Gaskets liner seals (TDI P/N 10 year overhaul.
Seals will be JF-019-000) have been changed at overhaul.
At last installed in the diesel refueling, seals were inspected in generators.
place and no leakage was found.
-2 Component No. Component Description Recommendation Comment 02-330B Flywheel Bolting It is recommended that This recommendation will be assembly procedures include tracked and implemented if the an effort to keep the flange flywheel connection is disassembled.
faces of the flywheel, crankshaft and generator shaft free of antiseize compound. Antiseize compound may still be used on the center alignment plug and to aid in driving the bolts at assembly. This recommendation is not essential to demonstrate adequacy of the bolts but is intended to produce a consistent design margin with other TDI engines.
Thus, it needs to be implemented only if the flywheel connection is disassembled.
02-345B Tappets and Guides:
Inspect tappet assembly The Owners Group has not defined Fuel Tappet Assembly to verify that it is free "measurable clearance."
SCE to rotate and there is no procedures currently provide measurable clearance acceptance criteria for the between the roller pin clearance as being 0.003 in to and cam roller.
0.010 in., in accordance with Appendix III of Section 8-4 in Volume I of the TDI Technical Manual.
02-350C Camshaft: Supports, Assemble and review Assembly and review of documentation Bolting and Gear existing documentation.
has not been completed. It will be (Task I of Appendix B) completed as appropriate and necessary in conjunction with the next task described below.
Perform quality inspections Results of quality inspections will outlined in Appendix B of be evaluated by SCE Engineering 02-350C and submit results by the end of Cycle X refueling for engineering evaluation.
outage.
-3 Component No.
Component Description Recommendation Comment 02-3658 Fuel Injection Nozzle Each assembly should be SCE's maintenance program for this Assembly disassembled, inspected, component conforms to Revision 2 of cleaned and reassembled, the Maintenance Matrix, but pop tested and have the differs from this recommendation.
spray pattern checked at Fuel injector tips are cleaned at each refueling outage.
every refueling outage with wet TDI SIM No's. 107 and 108 cloth.
If the tips do not get clean should be incorporated in by this method, they are replaced.
the San Onofre maintenance Complete disassembly, inspection procedures.
and cleaning of each nozzle assembly is not performed.
The Bendix fuel injection pumps are sent to a qualified vendor for overhaul.
SIN No. 108, which deals with tightening procedures for delivery valve holders and assembly nuts, is not applicable to maintenance items performed by SCE.
02-371A Fuel Pump Control Shaft, Review site documentation Procedures are being changed to Linkage Assembly and Bearings to ensure that bearing ensure that bearing lubrication lubrication procedures are is in accordance with the TDI in compliance with the Manual.
These procedure changes TDI Manual, will be completed by the end of Cycle X refueling outage.02-375 Intake Manifold and Upon reinstallation, ensure This recommendation is no longer Piping (Large Bore that manifold installation applicable as bolt hole diameters Scope only) does not cause excessive of the intake manifolds have been stress on flange bolt holes increased from 1/16 inch oversize due to misalignment, to 1/8 inch oversize to alleviate problems associated with misalignment, in accordance with an alternative maintenance option recommended by the Owners Group.
02-380A Exhaust Manifold In the event of an SSE, In the event of an SSE, the San Piping it is recommended that the Onofre Unit I procedures require Nelson studs, which hold that all safety related equipment the walls of the water on the plant be inspected for jacket together, be inspected damage and continued operability.
at some time subsequent to The cooling water jacket for the
-4 Component No.
Component Description Recommendation Comment the SSE event and replaced exhaust manifold piping is safety if the inspection warrants, related and will be inspected.
but the equipment will If signs of leakage are found, continue to operate safely then the Nelson studs, which are after a SSE event.
internal wall spacers, and are not normally accessible, will be inspected and will be replaced if the inspection warrants.
Adoption of an inspection An inspection program in accordance program to identify with this recommendation will possible degradation of be implemented by the end of exhaust manifold piping Cycle X refueling outage.
components, particularly welded joints, is recommended.
MM 19/20 Turbocharger To eliminate possibility This recommendation does not apply of core plugs inside to Elliott Model 65G Turbochargers, turbocharger nozzle ring which are in use at San Onofre hubs backing out and and which do not have this potential causing damage at San problem.
Onofre, it is recommended that at next turbocharger overhaul, but no later than the fourth refueling outage for any turbocharger, the nozzle ring core plugs be staked to prevent movement.
02-380B Exhaust Manifold:
Verify that proper torque "Proper torque" is understood to Gasket and Bolting was applied to exhaust mean torque which is sufficient to pipe flange capscrews.
hold capscrews tight and prevent leakage, rather than a specific torque value.
-5 Component No. Component Description Recommendation Comment 02-385B Cylinder Block Covers:
Verify that proper bolt These bolts are not listed in the Gaskets and Bolts torque loads (30 ft-lbs, table of special torque values of based on lead engine DR/QR Appendix IV of the TDI Technical report) are applied by Manual and are not critical to reviewing the existing engine operation. To prevent oil documentation.
leakage from the cylinder block covers, it is only necessary that these bolts be sufficiently tight.
Any bolts that fail can be readily replaced.
Use of a specific torque value adds to the maintenance costs without compensating benefits.
02-386B Crankcase: Crankcase Review the existing These bolts are not listed in the Gaskets and Mounting documentation or physically table of special torque values of Hardware verify that the bolt Appendix IV of the TDI Technical torques are in accordance Manual and are not critical to with the TDI manual.
engine operation. To prevent oil leakage from the crankcase, it is only necessary that these bolts be sufficiently tight. Any bolts that fail can be readily replaced. Use of a specific torque value adds to the maintenance costs without compensating benefits.
02-390C&D Main and Connector For future purchases of This recommendation was superseded Pushrods:
Rocker friction welded pushrods, by Revision 2 of the Maintenance Arms and Pushrods:
it is recommended that Matrix, which recommends only that Pushrods Connector the purchase order specify each friction welded pushrod destructive verification be inspected initially by of weld quality by liquid penetrant (LP).
SCE will sectioning random samples ensure that this LP inspection is from each manufacturing lot.
performed on all new friction welded pushrods prior to service.
02-390F Rocker Arms and Pushrods:
Perform a leak down rate SCE tested about 40 lifters.
Since Lifters test on two lifters.
this test requires kerosene fluid.
(low viscosity), over half of the lifters failed the test.
After discussion of the test results with Imo Delaval, the test was discontinued. So far Imo Delaval
-6 Component No. Component Description Recommendation Comment has not issued a revised test procedure requiring use of a higher viscosity fluid.
02-390G Rocker Arms and Pushrods:
At each refueling outage, This verification was performed Miscellaneous Bolts and verify that proper torque in 1985-86. The frequency of future Drive Studs is applied to rocker arm verifications will conform to bolts (365 ft-lbs).
Revision 2 of the Maintenance Matrix, i.e., verification will be performed "as required at reassembly."
02-411B Governor Drive:
Couplings, Inspect the Falk couplings There are no neoprene gap spacers Pins and Keys at each refueling outage.
in the Falk couplings in use at Replace the neoprene gap San Onofre Unit 1.
spacer.
In order to ensure appropriate This recommendation will be selection of replacement grids, incorporated in maintenance new grids should be inspected procedures and will be implemented to verify blue color code prior to installation of any new prior to installation in the grids.
coupling. This new color code indicates the improved shot peened grid.
02-415A Governor Assembly:
Modify the surveillance Test (a) of this recommendation Woodward Governor testing procedures to include will be implemented by the end an evaluation of the governor of Cycle X refueling outage and settings by means of the two then once per refueling thereafter tests given below:
in accordance with the Owners Group Maintenance Matrix. For this test, a) Perform a test of the the engine will be operated under governor settings while electrical governor control, with under joint electrical the mechanical governor operable and and mechanical governor serving as backup. Test (b) is not control, with the diesel included in the Maintenance Matrix generator off the grid in and will not be implemented.
the isochronous mode;
-7 Component No.
Component Description Recommendation Comment b) Perform a test of the governor settings while under mechanical (only) governor control, with the diesel generator off the grid in the isochronous mode.
These tests shall include rhe corresponding Maintenance Matrix examination of the engine recommendation is to "verify over speed transients during shoot of the 450 rpm set speed is start and transient loading within plant-specific guidelines conditions.
Included as and to avoid critical speeds part of the above tests, is during start or when unloaded." As the verification that the pointed out before in Reference F, engine set speed of 450 rpm speed transients are unavoid is not exceeded by more than able during engine startup.
This 11.2 percent (500 rpm max.)
entire recommendation will be either during an engine re-evaluated by the end of Cycle X start or during the largest refueling outage, and if determined single load reduction, to not present any problems, it will be implemented once per refueling outage.
Augment the setting adjustment This recommendation will be procedures, as described in evaluated and, if feasible, the Woodward manuals to implemented by the end of Cycle X include tests of the governor refueling outage.
response during an engine start to ensure agreement with the specifications indicated above.
Modify the maintenance Plant procedures will be modified schedules to ensure that by the end of Cycle X refueling the hydraulic actuator is outage.
vented per the Woodward Instructions when more than a half quart of oil is added to the unit.
-8 Component No. Component Description Recommendation Comment Modify the cleanness control This recommendation deals specification to ensure that with maintenance and appropriate procedures are surveillance (M&S), rather followed when adding or than quality revalidation changing governor oil so as inspection or component replacement not to contaminate fresh or modification. Cleanness of the oil and the interior of the fresh oil and of the governor governor.
interior at every oil change is ensured by following the existing San Onofre Unit 1 maintenance procedure for this oil change.
02-415B Governor Assembly:
The inlet and outlet lines Both inlet and outlet lines are part Booster Servomotor for the booster should be of the original diesel installation 3/8 inch and 1/4 inch tubing, and are 3/8 inch in diameter.
respectively.
According to discussions held between Imo Delaval and SCE, the existing size is standard for Imo Delaval engines and is acceptable.
02-425A Jacket Water Pump Drive gear nut torque should As stated in Reference F, these be reduced to 290 ft-lbs and items will be implemented by set as a "not to exceed the end of the Cycle X refueling value."
To minimize nut outage.
rotation required to insert locking cotter pin, a second hole should be drilled in the threaded end, 90 deg.
from the existing one.
02-4415*
Starting Air Manifold:
Free flowing drains should This modification is not needed Valves, Strainers, Filters be added to air distributor as starting air is desiccant filter.
dried and there is no evidence of moisture accumulation in the air filters.
The filters are periodically inspected in accordance with the Maintenance Matrix.
-9 Component No.
Component Description Recommendation Comment 02-455B Fuel Oil Filters & Strainers-Bowl bolt torques of 120-150 The bowl bolts for the motor and Strainers in-lb should be utilized during engine driven fuel oil pump reassembly of the strainer strainers are provided with a element.
T-handle for manual tightening. It is not practical to torque the bolts to a specified value.
02-467A-LB Generator Large Bore Turbo-Since the water jacket shroud As seen in TDI drawings, the water charger: Lube Oil Fitting-encases a portion of the piping jacket shroud does not encase any Piping components, it is recommended large bore piping. The flywheel that at the utilities' earliest shroud does encase some of this convenience, a comparison of piping. A comparison of the the as-built configuration with as-built inaccessible piping with TDI assembly details 100890 the TDI assembly drawings will be and 100902 be performed.
performed at the next disassembly of these components.
02-475A Turbocharger-Bracket It is recommended that the The bolts have been inspected (turbocharger bracket to for correct thread engagement engine block) bolts be and torque. Material verification inspected for correct could not be performed due to material, thread engagement the absence of a specification for and torque.
"correct material."
The bolt material is vendor supplied and there is no experience of loose or missing bolts at San Onofre Unit 1.
02-475B Air Butterfly Valve Assembly Modification:
Add grease TDI SIM 322 is specifically for HV fittings per TDI SIM 322.
and R engines and not for RV engines that are in use at San Onofre Unit 1.
Inspect butterfly to shaft The attachment pins are an attachment pins for signs interference fit with the shaft.
of distress.
Once removed, they are not reusable and must be replaced.
This replacement would invalidate any information provided by the inspection.
-10 Component No.
Component Description Recommendation Comment 02-500G Control Panel Assembly Valves To minimize fouling of the At each refueling, valves are control panel valves, the inspected for leaks but they have valves, including the fine not been cleaned nor will be mesh screen in the check cleaned, as this is not a valve, should be inspected recommendation of the Owners Group and cleaned during each Maintenance Matrix.
refueling outage. This recommended maintenance interval should be reassessed depending upon the degree of system fouling.
02-540A Lube Oil Sump Tank with It is recommended that at This inspection was performed Strainer Assembly and the next refueling outage, during the mid-cycle maintenance Mounting Hardware a sample of the tank seam outage of 1987.
No faulty welds and assembly welds be were found.
visually inspected....
The faulty welds should be repaired.
02-630r Pyrometer Conduit Assembly:
At every other 18 month According to Revision 2 of the Thermocouples maintenance outage, remove Maintenance Matrix, this clean and inspect each thermo-maintenance is to be performed couple and thermocouple shield as required."
The thermocouples for indications of fatigue.
and thermocouple shields are Any indication of fatigue located inside wells and do not should result in replacement normally require periodic cleaning of the thermocouple and/or or inspection. Any cleaning or thermocouple shieldT inspection of the thermocouples will be contingent on the results of the temperature indication check which is performed at every refueling, in accordance with Revision 2 of the Maintenance Mat r ix.
02-688A &
Engine and Auxiliary Perform an upgrade to tighten/ This recommendation will be 02-630A,B,C Module Wiring Material fix, replace-or add missing evaluated and any required and Fittings; Pyrometer conduit supports as required modifications will be implemented Conduit Assembly-Conduit, and to repair disconnected/
as part of the Integrated Fittings and Supports disjointed conduits.
Implementation Schedule for San Onofre Unit 1.
Component No. Component Description Recommendation Comment Additional supports are Same as above required at several locations for Category I rigid and flexible conduits.
02-695B Engine Shutdown Equipment To minimize fouling of the This inspection will be performed
-- Valves, Regulators, engine shutdown equipment only if the pressure gauge Orfices valves, regulators and indicates abnormal pressure orifices, it is recommended reduction during normal engine that the equipment be shutdown.
inspected and cleaned and the elastomeric parts be replaced during each refueling outage.
This recommended maintenance interval should be reassessed depending on the degree of system fouling.
02-717G Auxiliary Sub Base & Oil An inspection should be per-An inspection was performed and the
& Water Piping: Lube Oil formed to verify that the relief valves were found to be Valves.
relief valves have been installed in a horizontal position.
installed in a vertical According to discussions held position per the manufac-between SCE and Imo Delaval, the turer's recommendation.
existing valve position is acceptable and does not affect the relief capability of the valves.
02-717K Auxiliary Sub Base and Oil Same as for 02-717G above.
An inspection was performed and the
& Water Piping: Fuel Oil relief valves were found to be Valves installed in a horizontal position.
According to discussions held between SCE and Imo Delaval, the existing valve position is acceptable and does not affect the relief capability of the valves.
02-805B Intake Air Filter Inspect intake air filter Revision 2 to the Maintenance Matrix distribution plate and requires that air intake and oil change oil in filter at bath filters be inspected at 3 to each outage.
6 month intervals.
Based on the fact of limited engine operation
-12 Component No. Component Description Recommendation Comment during these short intervals, SCE elects to perform the inspection of air intake filters and distribution plate and oil bath filters at each refueling outage.
This is consistent with the original recommendation identified in this Table.
An oil change will be performed "if necessary," in accordance with the Maintenance Matrix recommendation.
041-127A Intercooler It is recommended that SIM SIM No. 365 is applicable to No. 365 be reviewed for intercooler adapters that have applicability and implemen-developed cracks.
It is presently tation at San Onofre.
not applicable to San Onofre Unit I (no cracks found in adapters).
02-380A, Large Bore Piping Perform specific modifications The piping components identified 02-467A, as described in DR/QR Report here have been reviewed 02-445C, independently by Impell Corporation 02-441A, in light of both the return to 041-127B,C, service and the long term seismic 02-43A and design criteria. Based on these 02-465A reviews, it is SCE's conclusion that the piping components are adequate and the Owners Group recommended modifications are not needed.
(For additional details regarding these reviews, refer to Reference G.)
02-CFR, Small Bore Piping Same as above Same as above 02-307D, 02-437A, 02-441C.
02-4508, 02-4500, 02-4-65A, 02-465B,
-13 Component No. Component Description Recommendation Comment 02-467A, Small Bore Piping Same as above Same as above 02-4678, 02-695A, 02-717E.
02-717F, and 02-717J IAA:8856F