ML20063P264

Informs That EMD Mi 9644 Mod Re Diesel Generator Prelube Oil Pump Mod Is Superior to NRC Proposed Fix & Meets Functional Requirements of License Condition 2.C.21.b. Prelube Would Degrade Reliability of Diesel Generators

ML20063P264
Person / Time
Site:	LaSalle
Issue date:	10/06/1982
From:	Schroeder C COMMONWEALTH EDISON CO.
To:	Schwencer A Office of Nuclear Reactor Regulation
References
5194N, NUDOCS 8210130233
Download: ML20063P264 (6)

Text

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s N Commonwealth Edison

) oris First NItional Pina ChicIgo, Ilhnois k '7 Address Reply to: Pori Offica Box 767

\s / Chicago, Illinois 60690 October 6, 1982 Mr. A. Schwencer, Chie f Licensing Branch #2 Division of Licensing U. S. Nuclear Regulatory Commission Washington, DC 20555 ,

Subject:

LaSalle County Station, Units 1 and 2 Diesel Generator Prelube Oil Pump Modification Operating License Condition 2.C. (21) . (b)

NRC Docket Nos. 50-373 and 50-374 References (a): LaSalle County Station, Unit 1 Facility Operating License No. NPF-ll.

(b): SER Section 9.6.3.4.

(c): October 8, 1981, letter from Mr. C.E. Sargent to Mr. A. Schwencer of the NRC on proposed changes to the LaSalle Technical Specification.

(d): November 18, 19 81, le t te r from Mr. C.E. Sa rgent to Mr. A. Schwencer concerning the diesel generator prelube oil pump modification.

Dear Mr. Schwencer:

Reference (a), Condition 2.C. (21) , (b) requires that: "A prelube pump, powered from a reliable direct current power supply, be installed in the system to operate in parallel with the engine-driven lube oil pump, or an alternative acceptable to the NRC shall be installed to preclude dry-starting o f the diesel-engine."

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Background

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[ In our letters of October 8, and November 18, 1981, and via several telecons with John Knox , Robert Giardina, and A. Bournia , we had

proposed an alternate solution that is recommended by EMD, the diesel engine manufacturer, and Stewart and Stevenson, the equipment supplier, for diesel engines subject to emergency starts. Our proposal was to t modify the lubrication system per EMD Maintenance Instruction 9644. This EMD modification will provide continuous lubrication for the moving parts in the lower part of the engine and maintain adequate oil level in the oil coolers and filters irrespective of oil viscosity. In our telecons with the NRC they had agreed that the EMD modification would correct the

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o jO a lubrication problem for'. the lower engine parts- but not for the upper

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engine parts such as the valve rocker arm assemblies and camshaft.

Our position was that prelubrication of the upper engine parts will-not improve engine -reliability .because the EMD1m'odification will

. decrease the time that upper deck lubrication. is achieved after a diesel start- and, therefore, prevent any damage to these parts.

Also, EMD and Stewart and Stevenson had verbally advised against installing.a:prelube oil pump. Reference. (c) and (d) describe the EMD modification and list our reasons for not adding the'prelube-pump.

Additional Information Since our last letter to the NRC on this subject, EMD and Stewart and Stevenson have confirmed in writing their position on the prelube pump modification. In a letter dated January 4,1982, EMD's District Engineer in Power Product Service, Mr. M.J.

Fleckenstein, informed Mr. Robert Giardina that the 48-hour prelube requirement does not apply to engines modified per 'EMD MI 9644. In a letter dated May 5,1982, Stewart and Stevenson recommended against the installation o f a prelube pump because it is not necessary and may degrade the reliability o f. the diesel. Th eir specific comments on the EMD and prelube pump modifications are as follows:

1. A DC driven prelube pump in parallel with the engine driven pump is not necessary because the EMD MI 9644 modification maintains: adequate lube oil levels within the engine to achieve upper deck lubrication after.very few revolutions o f the engine. Because bearing design and lube requirements are a function o f load and. speed, suf ficient residual oil will be present between normal shutdown periods for startup of the engine .without damage ~ to upper engine ~ parts.

2. MI 9644 maintains oil levels-in the engine at elevations which keep the lower oil gallery and passages flooded, thus preventing the entrance of air.

Overflow lines, properly elevated and sized, assure that lube level is m&intained below the upper engine components thus preventing hydraulic oil lock.

3.. MI 9644 modification was developed to increase diesel engine reliability and it does not adversely effect the operation of the engine.

4. Addition of a prelube pump in addition to the MI 9644 modification which was developed and tested by EMDlis

'not recommended because it would require additional components and circuits not developed nor tested by the

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engine manufacturer. Without such testing, it is difficult to determine what kind of 'roblems may be encountered.

The EMD and Stewart and Stevenson letter are enclosed as attachments to this letter.

Conclusion and Proposed Alternative We believe that the EMD MI 9644 modification is superior to the NRC's proposed fix and that it meets the functional requirements of License C9ndition 2.C.21.b. We have also concluded that the addition o f a prelube pump would degrade the reliability of the diesel generators because it will increase the probability of a hydraulic 011 lock. Our position is that we will not install any modification that will decrease the sarety of the plant or is not recommended by the vendor.

We purpose that, in light of the supporting documentation from EMD and Stewart and Stevenson, the NRC consider EMD MI 9644 as an acceptable alternative to the proposed prelube pump.

Because of normal delivery delays and design changes involved, Commonwealth Edison would appreciate your response in this matter by Friday, November 6, 1982. If the NRC does not find this alternative acceptable, Commonwealth Edison requests that a meeting be scheduled to further discuss this issue.

If there are any further questions in this matter, please contact this office.

One (1) signed original and thirty-nine(39) copies of this letter are enclosed for your use.

Very truly yours, CUR n,wsu l

C. W. Schroeder Nuclear Licensing Administrator

Enclosures:

cc: NRC Resident Inspector - LSCS File - LSCS Diesel Generators l 5194N l

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• STEWART & STEVENSON SERVICES, INC.

P.O. BOX 1637 . HOUSTON. TEXAS 77001 (713) 923-2161 TWX 910-881 1755

• TELEX 762301. CABLE: "STEWSTEVE*

May 5, 1982 Commonwealth Edison Company P. O. Box 767 - St1ED-35FW Chicago, Illinois 60690 ATTEtlT10ti: Mr. T. E. Watts SUBJECT  : LaSalle County Station Diesel Generator Lube Oil System Modification S&L Specification J-2544 CECO P.O. #155576 S&S W.0. #f164546 Gentlemen:

We apologize for the length of time it has taken to answer your letter of March 11, 1982. However, we still have not received a written reply from EMD stating their position on these pre-lube requirements. Our engineering comments, are as follows:

1. We do not recommend a D.C. pre-lube pump in parallel with the engine-driven pump. The M.I. 9644 modification maintains ade-quate lube oil levels within the engine to achieve upper-deck lubrication after very few revolutions of the engine. Since bearing design and lube requirement is a function of load and speed, sufficient residual oil will be present between normal periods of shutdown for startup.

2. M.I. 9644 maintains oil levels in the engine at elevations which keep the lower oil gallery and passages flooded, thus preventing the entrance of air. Overflow lines, properly elevated and sized, assure that lube level is maintained below the upper-engine components preventing hydraulic oil lock.

3. The M.I. 9644 modification was developed to increase engine reliability and does not adversely effect the operation of the engine.

4. As previously stated, we do not recommend a pre-lube pump in addition to the M.I. 9644 modification which was developed and tested by EMD. Addition of a pre-lube pump would require addi-tional components and circuits not developed or tested by the engine manufacturer. Without such testing, it is difficult to determine what kind of problems would be encountered.

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, May 5, 1982 Comonwealth Edison Company Mr. T. E. Watts Page - Two We will advise you as soon as further information is received from EMD in this regard.

Very truly yours, STEWART & STEVENSON SERVICES, INC.

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January 4, 1982 Mr. Robert Giardina Power Systems Branch, DSI _

United States Nuclear Regulatory Commission Washington, D.C. 20555 ,

Dear Mr. Giardina:

Enclosed is a copy of Modernization Recommendation M.I. 9644 per your request., ,

' Figures 1 and '10 on pages 2 and 17 provide a schematic rep-resentation of the modified system. In a'ddition to the first two pages, the section on Installation (page 6) and System Check and Operation (page 12) provides additional information on the operation of the system.

{' Since speaking with you on December 22, 1981, I have been adr'. sed that EMD will address in an upcoming Power Pointers art.'cle the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prelube questions as it applies to fast start engines equipped with the EMD immersion heater system and the modernization recommendation in Maintenance Instruction M.I. 9644. Basically, the Pointers will indicate that the 48 o hour prelube requirement does not apply to those engines so equipped. Details and exceptions will be provided in the Pointers article.

Regards, i b'f o 4 M. J. Fleckenstein District Engineer POWER PRODUCT SERVICE MJF:mes cc: J. G. Hayden I

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