ML17300A818

Summary of 870313 Meeting W/Consultants & Licensee at Site Re Evaluation & Repair of Diesel Generator Engine 3B.List of Meeting Attendees & Draft Responses to Staff Recommendations Encl

ML17300A818
Person / Time
Site:	Palo Verde
Issue date:	05/06/1987
From:	Licitra E Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
Shared Package
ML17300A819	List: ML17300A818 ML17300A820 ML17300A821
References
NUDOCS 8705110241
Download: ML17300A818 (22)

Text

8 MAY 1987 Docket No.:

50-530 LICENSEE:

Arizona Public Service Company FACILITY:

Palo Verde, Unit 3

SUMMARY

OF MEETING REGARDING EVALUATION AND REPAIR OF DIESEL GENERATOR ENGINE 3B A meeting was held at the Palo Verde site on March 13, 1987 among representa-tives of the NRC and its consultants, and the licensee.

The purpose of the meeting was to discuss the. recovery program for the damaged emergency diesel generator engine at Palo Verde Unit 3, and to address staff comments on this program provided by letter dated March 9, 1987.'nclosure I provides a list of meeting attendees and the meeting is summarized as follows.

~Summar Prior to addressing the recovery program and the staff's comments on the program, the staff and its consultant, Battelle-PNL, toured the ar ea where the affected diesel generator was located.

The staff was able to see the parts of the engine that had been damaged as well as the repair work that was in progress.

During the meeting, the licensee provided and discussed draft answers to the staff comments in the March 9, 1987 letter.

The draft answers are provided as Enclosure 2.

As a result of those discussions, the licensee stated that it would revise the draft to reflect the additional information presented at the meeting and submit the revised responses formally.

At the conclusion of the meeting, the staff stated that the tour and the discussions were helpful in providing a better understanding of (1) what had happened to the damaged EDG engine and (2) the recovery program for restoring the EDG to operable status.

The staff stated that the two remaining issues for reaching resolution on the acceptability of the recovery program were (I) the number of hours at full load that the repaired EDG engine is run before performing an examination of the engine and (2) the extent of the examination.

F 8705110241 870506 PDR ADOCK 05000530 PDR

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0 Arizona Public Service Co. Subsequent to the meeting, the licensee submitted the formal responses by letter dated March 24, 1987.

The responses also included information about run time at full load and an examination scope which are acceptable to the staff.

Orlglnel signed by; E. A. Licltra E. A. Licitra, Senior Project Manager Project Directorate V

Division of Reactor Projects - III/IV/V Im Special Projects

Enclosures:

(1) Meeting Attendees

2) Draft Responses to Staff Recommendations DISTRIBUTION

, Doc et Fi eg NRC PDR Local PDR GWKnighton EALicitra MDavis OGC-Bethesda EJordan JPartlow NRC Participants ACRS (10) uY DRSP/PDV DRSP/D:PDV EALicitra:cd GWKnighton 5/ P /87 5/ P /87 OFFICIAL RECORD COPY

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Van Brunt, Jr, Arizona Nuclear Power Project Palo Verde CC:

Arthur C. Gehr, Esq.

Snell 5 Wilmer 3100 Valley Center Phoenix, Arizona 85073 Mr. James M. Flenner, Chief Counsel Arizona Corporation Commission 1200 West Washington Phoenix, Arizona 85007 Charles R. Kocher, Esq. Assistant Council James A. Boeletto, Esq.

Southern California Edison Company P. 0.

Box 800

Rosemead, California 91770 Mr. Hark Sinsberg Energy Director Office of Economic Planning and Development 1700 West Washington - 5th Floor Phoenix, Arizona 85007 Hr. Wayne Shirley Assistant Attorney General Bataan Memorial Building Santa Fe, New Mexico 87503 Hr. Roy Zimmerman V.S. Nuclear Regulatory Commission P. 0.

Box 239 Arlington, Arizona 85322 Ms. Patricia Lee Hourihan 6413 S. 26th Street Phoenix, Arizona 85040 Regional Administrator, Region V

U. S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Kenneth Berlin, Esq.

Winston 5 Strawn Suite 500 2550 H Street, NW Washington, DC 20037 Hs. Lynne Bernabei Government Accountability Project of the Institute for Policy Studies 1901 Que Street, NW Washington, DC 20009 Hr. Ron Rayner P. 0.

Box 1509

'Goodyear, AZ 85338 Hr. Charles B. Brinkman, Manager Washington Nuclear Operations Combustion Engineering, Inc.

7910 Woodmont Avenue Suite 1310

Bethesda, Maryland 20814

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ENCLOSURE 1

Palo Verde Unit 3 Diesel Generator Heetin (March 13, 1987)

ATTENDEES Manny Licitra E. B. Tomlison Randy Buckhacter Ken Hoopingarner Frank Honer Tom Engbring John M. Horne Hark A. Bright Robert S. Sorenson Paul J.

Louzecky Richard A Bernier Ike Zerinque Bill Simko Jim Zatarack Hark Madden Charlie Miller AFFILITATION NRC/NRR/PBD7 NRC/NRR/PEICSB ANPP U-3 OMD SUPT Battelle - PNL ANPP - Nuclear Engineering ANPP - OPS Engineering Cooper Bessemer OHD - ANPP Battelle - PNL Consultant to PNL ANPP Licensing ANPP - Technical Support ANPP - OPS Engineering ANPP - OPS Engineering Cooper Bessemer NRC/NRR/PE I CSB

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ENCLOSURE 2 3B DIESEL ENGINE ANPP RESPONSE TO STAFF RECOMMENDATIONS OF MARCH 9, 1987 DRAFT Staff Recommendation 81 Cooper Energy Services.

should provide a vibration spectral analysis curve showing all the critical frequencies and their corresponding amplitudes from engine startup to engine overspeed.

It would be desirable to repeat with torsiograph of shaft rotation frequency test and compare the results with the original data.

A copy of the torsional vibration analysis should also be included in their report.

Cooper Energy Services has supplied a

Calculated Crankshaft Torsional Vibration Stress Curve of a typical Cooper KSV-20-T engine (Attachment No.

1).

This identifies all significant crankshaft resonant frequencies and corresponding stress amplitudes from O~o 800 rpm operating speeds.

These calculated results were compared to a 1978 Torsiograph Test Report (Attachment No.

2) for one of Palo Verde's engines (Cooper S/N 7183).

The correlati'on between the calculated values and measured values is excellent.

All natural frequencies are within 2X and all measured stress amplitudes are less than the calculated stress amplitudes, except the 6-1/2 order value which is slightly higher.

Cooper has calculated the change in resonant frequencies and torsional stresses due to the reduced crankpin diameter on Palo Verde's 3B diesel (Attachment No. 3).

The torsional frequencies for the Palo Verde 3B engine are predicted to change by less than 0.3X, and the crankpin torsional stresses are predicted to increase by 4-7X.

The variations from the original design

are, considered insignificant by Cooper Energy Services.

Based on these

results, Cooper Energy Services and ANPP believe a

torsiograph of the Palo Verde 3B diesel is not required.

Staff Recommendation 82 Cooper Energy Services should provide the results of their finite element analysis of the articulated and master rod )oint stresses

.and deflections.

This analysis should include the torsional vibration impact loads and stresses at'he critical connecting rod areas.

ANPP Res onse The finite element analysis of master connecting rod )oint is provided in Attachment No.

4.

Cooper concludes that the master connecting rod Minimum Cyclic Failure Factors in all locations are well above their design value of 2.25 and the design in acceptable.

Cooper also states in Attachment No.

5 that the operating stresses in the articulated rod are also within design limits.

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Staff Recommendation 83 If not already completed, Arizona Nuclear Power Project (Alg'P) should inspect critical engine

parts, such as the main and crankpin

bearings, camshaft bearings and surfpces, the valve mechanism

bearings, and the cylinder liners, to ensure that the additional 50 minute running time on the engine did not cause additional damage.

ANPP Res onse Included 'in the engine recovery effort is a complete inspection of critical engine parts.

This inspection includes a visual examination of the main and crankpin bearings and journals, articulated rod pins and

bushings, camshaft bearings and journals, valve mechanism bearings and bushings, cylinder liners,

pistons, piston rings, piston pins and bushings',

and cylinder heads.

Magnetic particle NDE has also been performed on the cylinder heads'iredomes to verify absence of cracks.

All damaged parts will be documented and replaced or reworked as appropriate.

Staff Recommendation 84 ANPP should provide the results of the crankshaft evaluation, (hot and cold crankshaft deflection test) showing that the connecting rod and counterweight damage did not bend the crankshaft.

ANPP Res onse ANPP will provide the results of the crankshaft evaluation, (hot and cold crankshaft deflection test).

The initial cold web deflection will be measured prior to running the engine.

The initial hot web deflection will be measured after the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of operation.

Staff Recommendation 85 Cooper Energy Services should provide a written analysis indicating that post-failure engine operation did not cause any torsional or vibration damage.

ANPP Res onse Cooper Energy Services has analyzed the effects of off-design operation, i.e 45 minutes of operation at approximately 296 rpm with no load (Attachment No.

3).

The analysis shows that the crankshaft suffered no damage under these conditions.

Staff Recommendation 86 ANPP should inspect the crankshaft to insure that there are no cracks in the No.

9 cylinder area, including the crankpin or journal fillets and oil holes at cylinders No.

8, 9

and 10 journals.

ANPP should also consider the possibility that crankshaft cracks may have developed due to the rapidity of the failure.

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ANPP Res onse All crankshaft journals will be visually examined during bgaring inspection.

A 'liquid penetrant NDE was performed on the crankshaft-No.

9 cylinder connecting rod joyrnal after machining and polishing to verify the absence of cracks.

In addition to the visual inspection, liquid 'penetrant NDE will similarly be performed on the No.

8 and No.

10 cylinders connecting rod journals.

Staff Recommendation 87 ANPP should inspect the torsional vibration damper to insure proper function prior to the failure and continued function in future operation.

The torsional vibration damper will be inspected as per the vendor's recommendations given in the engine service manual.

This inspection will be performed prior to declaring the engine

operable, and is also part of the annual surveillance test on the engine.

~4V Staff Recommendation 88 ANPP should inspect the engine for water leaks and analyze the oil for water after the repai'r is completed to show that the damaged cylinders do not leak water into the oil.

Also,,the oil should be analyzed for metal content to look for residual debris or post failure wear.

ANPP Res onse As part the testing to be performed, the jacket water system will be hydrostatically tested and inspected prior to putting oil into the engine.

The engine will again be inspected internally during the initial break in period for water leaks.

The new lube oil will be analyzed after the initial break in period during the scheduled surveillance test for water,

dirt, viscosity and wear metals.

Staff Recommendation 89 ANPP should inspect the master rod crankpin bearing~a~

shell after operating the engine to be sure it is operating satisfactorily.

From the photographs which were shown, it appeared that there was a section of the crankpin journal that was not cleaned up.

This damaged surface should be evaluated as a potential cause of future crankpin bearing trouble.

The No.

9 crankpin journal was reduced in diameter by about

.175 inches to remove most of the damage~b~.

Slight surface damage is still visible.

It is not known if the crankpin bearing will operate satisfactorily on this slightly damaged journal surface.

In order to show satisfactory operation, the crankpin bearing should be inspected after some period of full load operation.

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(a)

Often when an engine throws a

connecting

rod, the crankshaft is bent.

Therefore, to determine if this crankshaft is straight, a hot and cold crankshaft deflection test showing the deflection at all the cylinders should be required.

Then, during the early running of ahe

engine, a hot "feel-over" gest should be required to demonstrate that all the bearings are operating normally.

(b)

The damaged crankpin journal was ground to remove the nicked and scuffed areas.

This journal at No.

9 cylinder was reduced in diameter about

.175 inches.

This reduction in crankpin diameter appeared to leave a small damaged area on the journal surface which needs to be repaired.

ANPP Res onse The damage to the No.

9 cylinder connecting rod'ournal was completely removed by machining and polishing to a diameter of 11.323 inches.

CES will supply replacement oversized bearing shells for installation.

This journal meets all original CES fabrication specifications, and will not be subject to any additional inspection after initial engine operation.

All main and connecting rod bearings are equipped wit/ protectiv~ devices to trip the engine in the event of bearing high temperature.

Routine bearing inspection will be performed in accordance with CES recommendations.

Staff Recommendation 810 ANPP should verify that no iron plated connecting rods are used in any of the Cooper Energy Services'ngines at the Palo Verde Station.

ANPP Res onse In the RER-QSE 86-47 Final Report dated February 9,

1987, ANPP stated that iron plating was only used on three master connecting rods at PVNGS.

These rods were identified as Number 9 in engine 2A and Numbers 2

and 9 in engine 3B.

This was verified by a

complete review of Cooper's manufacturing deviation reports for master connecting rods and articulated rods supplied to ANPP.

The review was conducted by Cooper Energy Services and witnessed by ANPP Quali.ty Assurance Personnel.

As stated in RER QSE 86-47 Final Report, the three iron plated rods at ANPP have been replaced.

Staff Recommendation //ll ANPP should verify that no nickel sprayed rods are used in the Cooper Energy Services'ngines at the Palo Verde Station, except in low stress areas, until it can be shown that the physical properties of the nickel-sprayed metal are capable of transferring the stresses without developing any cracks.

ANPP Res onse In the RER QSE 86-47 Final Report dated February 9,

1987 ANPP stated that nickel spray is only found on Master Connecting Rod Number 3 in the Unit 2A engine and Master Connecting Rods Number 1, 3,

and 9 in the Unit 2B engine.

This was verified by a

complete review of Cooper's manufacturing deviation

reports for master connecting rods and articulated rods supplied to ANPP.

The review was conducted by Cooper Energy Services and witnessing ANPP Quality Assurance personnel.

The deviation reports identified that nickel metal spray was applied to the bale areas of the master connecting rods to correct some grooves on the bearing surfaces.

Cooper Energy Services'inite element analysis model of the master connecting rod crankshaft and articulated rod bore area shows that the bale area Minimum Cyclic Failure Factor is 4'0 at 600 rpm and 3.29 at 660 rpm.

In the finite element analysis

report, Cooper concludes that these values are well above their design value at 2.25 and constitutes a low stress area.

Staff Recommendation 812 Cooper Energy Services should identify the high stress areas in the connecting rods.

This would assist in identifying the areas that need to be critically evaluated prior to being in place in an engine.

ANPP Response Cooper has identified the high stress areas Mn the master connecting rod and documented them with a finite element analysis (Attachment No. 4).

This document concludes that all Cyclic Failure Factors exceed the 2.25 design value Cooper requires.

Cooper has stated that the articulated stress levels are straight forward and have been verified by strain gage testing on similar designs (Attachment No. 5).

Staff Recommendation 813 Any used oil from the damaged engine should be analyzed to show if there were

'ny abnormalities in the oil, such as corrosive constituents, that could have contributed to the failure.

ANPP Response Oil removed from the lube oil system will be analyzed for wear metals,

water, dirt, viscosity and acidity..

Staff Recommendation 814

'I Use of fire extinguisher chemicals on fires in turbines has been known to initiate intergranular stress corrosion cracking in certain materials.

The effect of the fire extinguisher foam residue on engine materials should be carefully evaluated.

ANPP Response The fire extinguisher chemicals had no adverse effect on the diesel generator components.

The foam mixture used at PVNGS is a mild solution of more than 99X water and approximately 1X glycol (butyl carbitol).

The water/foam mixture was injected into a relatively cold crankcase.

The only engine components with high temperatures at the time the water/foam mixture was injected were those cylinder assemblies running on lube oil.

Due to the entry

location, the water/foam mixture would not be expected to contact these components.

Also, the engine components that were exposed to the water/foam were coated with oil, which acted as a barrier from the water/foam mixture.

Fire extinguisher chemicals on turbines are considered more damaging due to the elevated temperatures and lack of oil protection on turbine engines.

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ATTACHMENT 1 CALCULATED CRANKSHAFT TORSIONAL VIBRATION STRESSES KSV-20-T ENGINE

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ATTACHMENT 2 TORSIONOGRAPH TEST REPORT KSV-20-T ENGINE