ML17277B505

Responds to 840702 Generic Ltr 84-15 Re Diesel Generator Reliability.Facility Meets or Exceeds Commission Intent for Diesel Generator Increased Reliability Program.Fast Cold Starting Not Applicable

ML17277B505
Person / Time
Site:	Columbia
Issue date:	09/28/1984
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Schwencer A Office of Nuclear Reactor Regulation
References
GL-84-15, GO2-84-524, NUDOCS 8410050335
Download: ML17277B505 (12)

Text

REGULATOR INFORMATION DISTRIBUTION TEM (RIDS)

ACCESSION NBR:8010050335 DOC ~ DATE: 8g/09/28 NOTARI'ZED: NO DOCKET FACIL:50-397 NPPSS Nuc1 ear Pr o ect g Unit 2i Nashington Public Powe j 05000397 AUTH, NAME AUTHOR AFFILIATION SORENSENfGtC, Nashington Public Power Supply System REC IP. NAME RECIPIENT AFFILIATION SCH'tdENCERgA, Licensing Branch 2 SUBJECT; Responds to 840702 Generic Ltr 80 15 re'iesel generator reliability'acility meets or exceeds Commission intent for diesel generator increased reliability program, Fast cold starting not applicable.

DISTRIBUTION CODE: A056D COPIES RECEIVED:LTR ENCL

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TITLE: OR Submittal:Fast Cold Starts of Diesel GL-83 Pl NOTES: 05000397 OLo12/20/83 RECIPIENT COPIES RECIPIENT COPiES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL NRR LB2 BC 01 INTERNAL: ADM/LFMB AEOD 07 IE/DEPER/EAB 08 NRR/DL/ORAB 09 N SB 10 NRR/DST/SPEB 11 EG 0ll RES/DRA/RRB 12 5 06 EXTERNAL: ACRS NRC PDR NTIS 02'PDR 13 NSIC 03 05 TOTAL NUMBER OF COPIES REQUIRED: LTTR 22 ENCL 1

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Washington Public Power Supply System P.O. Box 968 3000 George Washington Way Richland, Washington 99352 (509) 372-5000 840928 84i005033Q 05000397 PDR ADOCK PDR September 28, 1984 G02-84-524 Docket No. 50-397 Director of Nuclear Reactor Regulation Attention: Mr. A. Schwencer, Chief Licensing Branch No. 2 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 RESPONSE TO GENERIC LETTER 84-15, DIESEL GENERATOR RELIABILITY

References:

Letter, D. G. Eisenhut (NRC) to All Licensees of Operating Reactors, Applicants for an Operating License and Holders of Construction Permits, Generic Letter 84-15, Diesel Generator Reliability dated July 2, 1984

2) NSAC-79, A Limited Performance Review of Fairbanks Morse and General Motors Diesel Generators at Nuclear Plants Regulatory Guide 1. 108, Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants

..4) NUREG/CR-0660, "Enhancement of Onsite Emergency Diesel Generator, Reliability, February 1979" "

As requested by reference 1, the Supply System hereby provides the following responses:

Item 1. Provide a description of the current program to avoid cold fast star t surveillance testing or intended actions to reduce cold fast starts.

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A. Schwencer Page Two September 28, 1984 RESPONSE TO GENERIC LETTER 84-15, DIESEL GENERATOR RELIABILITY WNP,-2 Res onse Cold Fast Start,Testin WNP-2 units are equipped with keep warm systems, continuous pre-lube systems and heavy duty .turbo charger drive trains. They are not started cold and they are not started without pre-lubrication. During surveillance tests, loads are applied by paralleling with the grid and loaded gradually to full power .over a.period of .45 - 60 seconds.

The Supply System does not consider this method of starting and loading as a "cold fast start". For the above reasons, a program to reduce cold fast starts at WNP-2 is'ot applicable; the ability to perform a cold fast start is effectively nullified by the keep warm, pre-lubed, heavy duty turbo charger design of the WNP-2 units. A program to reduce cold fast starts would only be applicable to units not comparably equipped as the WNP-2 units.

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'Pl Although not having a cold fast start concern, the Supply System is of the opinion that other starting. requirements specified by the Technical Specifi-cations contribute to premature diesel engine degradation.

WNP-2 operates under the standard Technical Specifications referenced in Generic Letter 84-15 and is not affected by the proposed changes however, the Supply System. recommends that the number of required surveillance tests be'reduced significantly by changing the. periodicity of the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> testing required by Technical Specification 3.8. 1.1 to not more than once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Further reduction in suryeillance.test starts should be achieved by allowing credit for post.-maintenance. testing and actual demand starts accomplished outside the "staggered test basis" as specified by Technical Specification'4.8.1."1.2 providing the 31 day,period was not exceeded.

Item 2. Provide current reliability data for each diesel generator based on surveillance testing.

'~RRP,-'2 2 Diesel. Generator Reliabilit Data t

'enerator 'Failure Last'20'Starts Failure Last 100 Starts ~Hister DG1A DG18 Failed on July 9, 1984~

DG1C

, ~Generator Bearing Failure (See LER-84-075) -- not engine related

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A. Schwencer Page Three Seotember 28 1984 RESPONSE TO GENERIC LETTER 84-15, DIESEL GENERATOR RELIABILITY Item 3. Provide a description of the current program for attaining and maintaining a reliability goal for diesel generators.

WNP-2 Res onse The reliability program at WNP-2 consists of an aggressive maintenance program, comprehensive evaluation of indicated operating parameters resulting in the immediate correction of any minor problem or perceived weaknesses as they become apparent in the WNP-2 units, and evaluation of incidents on similar units at other plants with corrective action as applicable on the WNP-2 uni ts. Additionally, evaluation and incorporation of the manufacturer 's recommended modifications and operating practices receive high priority and are evaluated and incorporated if appropriate.

It is the Supply System's position that the existing WNP-2 program exceeds the requirements and recommended practices of Reg. Guide l. 108, NUREG/CR-0660 and NSAC-79.

The statistical data. contained in Appendix B of NSAC-79 encompasses 149 LER's pertaining. to diesel. generator failures from plants with END diesel engines. Of the 149 reported failures, two (1.3%) could possibly be attributed'o cold fast starting practices. Therefore, the Supply System considers that, overall reliability improvement of diesel generators re-quires much more effort than the simple reduction of cold fast starts, and should include careful trending and evaluation of individual components and sub-systems; which is the current WNP-2 practice.

Comments'on Exam'le.Technical S ecifications The example, Technical Specification allowing the option for warm pre-lubed starts prior'o surveillance testing should result in improvement in the service time of the 'engines. The. Technical Specification is interpreted to .read that in the event of. a'ailure to a specific unit, then only that specific unit is- subject to increased testing. The Supply System agrees that this would reduce wear and degradation of the remaining units.

Increased. testing requirements do not increase the reliability of diesel engines or statistically indicate that. reliability is increased. Speci-it fically, will only cause. further wear and degradation of the unit.

In the. event of a failure, the root cause must be positively identified and;corrected 'with.due consideration to investigation of other units.

The only:meaningful requirement for .testing is a demonstration that the required repair work was done correctly. Testing, in itself, provides a sense of'false security. As an example, failure to start because of a failure of an'electrical contactor, caused by dust or moisture, is not necessarily proven to be, resolved by an additional seven successful star ts in a,short period of time. In this case, effort spent in identify-ing and correcting the contactor problem would be of more benefit than testing.

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0 A. Schwencer Page Four September 28, 1984 RESPONSE TO GENERIC LETTER 84-15, DIESEL GENERATOR RELIABILITY An additional suggested Technical Specification change would be to require that each failure report include a detailed failure analysis and evidence that the root cause was precisely identified and corrected. More frequent diesel generator testing should only be required when the root cause cannot be identified. The analysis may indicate that the failed component requires additional testing rather than a diesel generator test. Prolonged runs at load are only meaningful when the load carrying capability of the engine or the generator itself is in doubt. The statistical data of NSAC-79 indicates that this is rarely the case.

Summation It is the Supply System's conclusion that WNP-2 meets or exceeds the Commission's intent for a Diesel Generator Increased Reliability Program and that fast cold starting, as an issue, is not applicable to this plant. WNP-2 maintains the required records and Preventive Maintenance Program as recommended by Reg. Guide 1.108 and NUREG/CR-0660 as well as detailed trending and analysis programs with emphasis on early trouble detection and correction. Coupled with the suggested relief gained by allowing credit for post maintenance starts, actual demands and reduced testing of non-affected units after a failure, the WNP-2 program, as it exists, would be vastly improved.

Should you have any questions, please contact Mr. P. L. Powell, Manager, WNP-2 Licensing.

Very truly yours, G. C. Sorensen Regulatory Programs PLP/tmh cc: R Auluck - NRC WS Chin - BPA JB Martin - NRC RV AD Toth - NRC Site

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Response to Generic Letter 84-15 STATE OF WASHINGTON )

Subject:

Diesel Generator Reliability

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County of Benton )

I, G. C. SORENSEN, being duly sworn, subscribe to and say that I am the Manager, Regulatory Programs, for the WASHINGTON PUBLIC POWER SUPPLY SYSTEM, the applicant herein; that I have full authority to execute this oath; that I have reviewed the foregoing; and that to the best of my knowledge, information and belief the statements made in-it are true.

DATE Q . , 1984 G. C. Sor sen, Manager Regulato Programs On this day personally appeared before me G. C. SORENSEN to me known to be the individual who executed the foregoing instrument and acknowledge that he signed the, same as his free act and deed for the uses and purposes therein mentioned.

GIVEN under afy hand and seal this ~/%day of , 1984.

ry u sc sn n or e A

State of Washington Residing at

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