ML20107B616

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Responds to Generic Ltr 84-15 Re Diesel Generator Reliability.No Changes to Tech Specs Anticipated Due to Reliability of Util Diesel Generators.Evaluation of Staff Recommendations & NUREG/CR-0660 Findings Encl
ML20107B616
Person / Time
Site: Beaver Valley
Issue date: 10/24/1984
From: Carey J
DUQUESNE LIGHT CO.
To: Eisenhut D
Office of Nuclear Reactor Regulation
References
REF-GTECI-A-44, REF-GTECI-EL, TASK-A-44, TASK-B-56, TASK-OR GL-83-28, GL-84-15, NUDOCS 8411020263
Download: ML20107B616 (26)
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'Af Telephone (412) 393-6000 Nuclear Division P. O. Box 4 shippingport, PA 15077-0004 October 24, 1984 Director of Nuclear Reactor Regulation i

U.S. Nuclear Regulatory Commission Attn:

D. G. Eisenhut, Director Division of Licensing Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 Diesel Generator Reliability (Generic Letter 84-15)

Gentlemen:

We have completed our review of the subject letter and evaluated the Staff concerns and recommendations in the areas of:

cold fast starting diesel generators; revised technical specifications; compliance with vendor recommendations; perfonnance reliability; and the findings of NUREG/CR-0660,

" Enhancement of Onsite Emergency Diesel Generator Reliability, February 1979."

We recognize the importance of maintaining the diesel generators' reliability at the highest level attainable, but also believe that the Non-IE sources of power to the emergency electrical system should be similarly maintained to insure that the challenges to the emergency power system are minimized.

To this end, we have already made humerous modifications to operating and maintenance procedures and plant design (Attachment 3) to enhance the reliability of the diesel generators and the Non-1E electrical sources of power to the energency busses.

We have stated in a past submittal (Generic Letter 83-28) that we believed the database for some of the background documents being utilized in the Staff review of Unresolved Safety Issue A-44, Station Blackout, may not have represented a totally accurate historical indicator of the overall reliability of emergency diesel generators.

This is based on the considera-tions discussed below.

Some of the reported diesel failures utilized in the database did not represent actual failures in the ability of the diesel to start under emer-gency conditions and assume load on the emergency bus. Due to the reporting requirements in effect during that period, many of the recorded failures appear to have been interpreted as events which would have actually pre-vented the diesel from perfonning its emergency function. This was due, in part, to the inadequacies of the Licensee Event Reports submitted by the 66 8411020263 841024 h0 PDR ADOCK 05000334 p

PDR 11

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-October 24, 1984

' Beaver-Valley Power Station, Unit No.1:

Docket No. ' 50-334, License No. DPR-66 Diesel' Generator Reliability (Generic Letter 84-15)

Page:2; utilities to' discriminate between relatively minor test deficiencies and

-actual -failures which would have inhibited the diesel from starting or assuming load under a loss of offsite power (LOP) condition. An example of this.is that many starting failures were recorded because the diesel did not start when the' manual pushbuttons were actuated ~in the control room.

At BV-1, different relays and contacts are used to start the diesel under a LOP condition than when a manual start is initiated from the control

. room, the problem cannot be assessed as a bona fide failure until the exact

- mechanism is _ identified and reviewed for its potential f ailure contribution during a LOP condition.. A second example of this would be that additional

' diesel starting failures were reported because the first bank of air start-ing motors failed to start the diesel, although in many cases the second bank'of motors did, in fact, automatically start the unit in an acceptable time frame.

Another example of reported failures which contributed to the database can be classified as breaker failures, whereby the generator output breaker

-failed :to close on demand during a test sequence. Without properly identi-fying the root cause of the failure in the LER and evaluating the failure mode under'a LOP condition, a proper detennination cannot be made as to

'whether, the breaker would have actually closed under a LOP. This is due to the fact that when a diesel is paralleled to the bus with the Non-1E

. power source, a number of interlocks and synchronizing circuits are uti-

~ lized which would be bypassed under actual LOP conditions.

In retrospect, it is difficult to assess a relay failure mode and determine if the test failure would have also occurred under an actual' LOP since the corrective action usually replaced the relay, or cleaned all of the contacts.

For purposes of conservatism, it was assumed that the failure would have inhi-bited the diesel from operating under a LOP unless it could be excluded

{

through specific review of the maintenance work order.

L We believe the Staff has also recognized this reporting problem and p

, taken appropriate action through a more meaningful interpretation of

" failure" in Regulatory Guide 1.108 and subscribed to this-definition with i.

L the issuance of Generic Letter 84-15.

l We are not suggesting that.the database for USI A-44 be reevaluated based on these considerations because we believe that diesel reliability F

and grid stability are areas upon which the industry can improve to reduce L

their contribution to risk; however, we would recommend that licensees be I

required to assess the failure mechanism under LOP condition to insure that

-the future ~ inputs to the database are not biased with a number of events p

~

which may be classed as testing deficiencies. A similar methodology should i

. be applied when requesting licensees for input to other databases to insure that the information gives an accurate accounting for risk assessment pur-l poses and safety issue prioritization.

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r Oct:ber 24, 1984 Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 Diesel Generator Reliability (Generic Letter 84-15)

Page 3 Our evaluation of the reliability goal and proposed technical specifi-cations methodology of Generic Letter 84-15 has identified similar concerns and, as requested, we have provided comments in Enclosure 3 and Attachment 4.

We are not submitting revised specifications to reduce the number of cold fast starts as requested in Enclosure 1 as we have not identified any past failures related to this mode and do not consider the existing speci-fications detrimental to diesel perfonnance.

Attachments 1 and 2 provide a summary of diesel generator demands and failures which we will update at each refueling cycle. sum-marizes the reliability and test data as requested.

Based on the present reliability of our diesels (past 20 tests, 20.95),

and other reliability-oriented methods of assuring that all safety-related equipment failures are thoroughly reviewed to avoid symptomatic repairs, we do not find it necessary to incorporate a diesel generator reliability program into the Technical Specifications at this time. We will provide the reliability level of the diesel generators with future LERs following this refueling outage to measure the effectiveness of our programs in this area.

As stated in the enclosure, a reliability assurance program which is unique to the diesels has not been implemented as it is an inherent part of the overall corrective action network which embraces all safety-related equipment. We are continuing to upgrade maintenance and operating proce-dures based on reported and non-reportable failures on all safety-related equipment.

We believe that overall plant performance and the reliability of all safety-related equipment are inextricably linked through our desire to maximize these factors and the requirements of the Technical Specifications.

We believe the actions which have been taken in conjunction with those planned will be responsive to USI A-44 and B-56.

This report is current as of August 1984.

If you require additional infonnation, please contact my office.

Very truly yours, J. J. Carey Vice President Nuclear Group Enclosures

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' October 24, 1984 Beaver Valley Power Station,' Unit No.1 Docket No. 50-334, License No. DPR-66 Diesel Generator Reliability (Generic Letter 84-15)

Page 4 cc:

U. S. Nuclear Regulatory Commission Division of Licensing Attn: Steven A. Varga, Chief Operating Reactors Branch No.1 Division of Licensing Washington, DC 20555 Mr. W. M. Troskoski, Resident Inspector U.S. Nuclear Regulatory Commission Beaver Valley Power Station Shippingport, PA 15077 U.S. Nuclear Regulatory Commission c/o Document Management Branch Washington, DC 20555 Director, Safety Evaluation & Control Virginia Electric & Power Company P.O. Box 26666 One James River Plaza Richmond, VA 23261

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COMMONWEALTH OF PENNSYLVANIA) 1SS:

COUNTY OF BEAVER On thi,s g[M day of M

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before me, // M 4 //1 9 % l b u,

a Notary Public in and for said.

Commonwealth /and Coutfty,. personally appeared J.

J.

Carey, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) the statements set forth -in the ' Submittal are true and correct to the best of his knowledge, information and belief.

4 W', W SkillA M. f AlittE. II0iARY PUSLIC

$NIPPilIGPORT 9080, SEAMR COUNTY uf C0stels5005 EIPlats SEPT.16,1985 Member.Pennsylvanie Association of Notaries 4

r ENCLOSURE 1 REDUCTION IN COLD FAST START SURVEILLANCE TESTS FOR DIESEL GENERATORS Surveillance Requirements Beaver Valley' Technical Specification 3/4.8.1 provides the surveillance requirenents for the diesel generators.

In summary, this specification requires:

1.

At least once per 31 days on a staggered test basis, verification that the diesel. starts from ambient condition and the generator is synchronized, loaded to 21425 KW, and operates for 260 minutes.

2.

At least~once per 18 months during shutdown, simulate a loss of off-site power in conjunction with a safety injection signal verifying the diesel starts fran ambient conditions, energizes the emergency busses with permanently connected loads, energizes auto-connected ~

loads through the load sequencer, and operates for 25 minutes with the energency loads.

At least once per 18 months during shutdown, verify the diesel oper-3.

ates for 260 minutes while loaded to 22750 KL.

4.

With one offsite circuit and/or one diesel generator or two offsite circuits-inoperable, verify that the diesel starts from ambient con-ditions within.one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter.

Manufacturer ' Recommendations L

The following practices are recommended by the manufacturer, Electro-Motive Division of General Motors, when testing the diesel generators:

4 1.

The engine be started and run at idle speed for a period of 3 to 5

,~

. minutes to alleviate loading of unlubricated engine parts during the interval when the lube oil pump is' filling the engine lube oil passages.

2.

To eliminate discharge of unburned lube oil into the exhaust system, the diesel generator should be operated with 250% load, but not less than 20% load, and prior to shutdown, the unit should carry at least 75% load for one hour.

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t-ENCLOSURE 1 Page 2 Testing Program Testing to meet the surveillance requirements at Beaver Valley Unit 1 is-perfonned under Operating Surveillance Tests (OSTs) 1.36.1, 1.36.2, 1.36.3, and 1.36.4.

~

OSTs 1.36.1 and -1.36.2.are monthly -tests which start the diesel from ambient

- conditions.and verify synchronizing and loading.

Following the manufac-turer recommendations,- the engine is allowed to idle for several minutes and is checked for proper operation prior _ to increasing speed and loading.

. The generators are then loaded to 2850 KW (100% design) for atoleast one

-hour.

In addition, these-tests are used when an AC source is inoperable, but only to verify diesel starting with no loading performed. When the OSTs are used for. this,- the manufacturer recommendation of loading is not followed.

OSTs 1.36.3 and 1.36.4 are 18-month tests which fast cold start the diesels

- and verify auto loading and operation for h5 minutes. The manufacturer's recommendations of idling before loading and loading at 275% inad for one hour are not followed during these tests since an outage condition and plant ~ design do not provide sufficient load under a condition whereby the

. 1E bus;is separated from.the Non-1E source.

Action to Reduce Fast Cold Starts We believe that the current testing program and requirements of fast cold starts every refueling are not excessive. - Therefore, no program to reduce fast cold starts is in place, and no additional action is considered neces-sary for reducing the number of tests 'which fast cold start the diesels.

The few tests which do not follow manufacturer's recommendations are not considered to excessively degrade the diesel since they:are not performed often.

In. reference.to prelube recommendations, Beaver Valley Unit I diesel gener-ators have an auxiliary oil system which supplies wann oil to the turbo-charger and engine sump when the engine is shut down.. This system operates continuously and, with the engine shutdown, maintains engine oil temperature and lubrication for fast starting. A design change (DCP 452) which in-cludes a second oil pump was also completed to assure proper system-opera-tion after a " hot shutdown" from a previous run.

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. ENCLOSURE 2 DIESEL GENERATOR RELIABILITY DATA Da ta Attachments'1 and 2 provide a-time history of diesel generator. demands and failures for the Number 1 and 2 diesel generators, respectively, for all demands / failures during the last 100 valid demands and failures.

- The criteria used-to determine a valid demand / failure are contained in Regulatory Guide 1.108, Revision 1, August.1977, ' position C.2.e.

With this criteria, starts due to a safety injection signal, where diesel operation is terminated without loadin considered valid demands.

(g to 50% load for at least one hour,.are not positions C.2.e.(3) and (4))

Using the data in the attachments, the reliability of each diesel generator is:

Number of Failures Reliabil i ty*

No. 1 Last 20 Demands 1

0.95 No. 1 Last 100 Demands-15 0.85 No. 2 Last 20 Demands 1

0.95 No. 2 Last 100 Demands 14-0.86

  • Reliability calculated by 1.0 - Number of Valid Failures / Number of Demands Records and Reports Beaver Valley Unit I does not currently maintain a record itemizing the demands and failures experienced by each diesel generator as outlined in Regulatory Guide 1.108, position C.3.a,- nor maintain a yearly data report for each diesel generator.

However, as'part of the Operational Assessment Group's review and tracking o

i of Incident Reports and Licensee Event Reports, any reportable failure would be tracked for corrective action, reviewed against past reportable failures, and reported in a monthly trend report.

i-In addition, Enclosure 3 describes the present method of maintaining reliability, and it is our intent to maintain and update Attachnents 1 and 2 at each refueling cycle.

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ENCLOSURE 3 DIESEL GENERATOR RELIABILITY Reliability Improvements Program

. Beaver Valley Unit 1 does not presently have a diesel generator-specific reliability program to attain and maintain a specific reliability goal.

However, as with all safety-related equipment, reliability is assured and maintained by:

1.

Successful performance of technical specification surveillance require-

'ments.

(See Enclosure 1 for diesel generator requirements and tests.)

2.

Reviewing failures to determine the root cause and taking corrective action to resolve the root cause.

(SeeAttachments1and2.)

8 3.

Review of failures against past failures for repetitive failures.

4.

Reviewing manufacturer and industry information for applicability to the facility and possible improvements.

5.

A planned program of preventive maintenance.

As a result of the above method of maintaining reliability, many design changes have been completed or planned to increase diesel generator reli-abili ty. Attachment 3 provides a summary of these design changes.

To aid in the above reviews, we will maintain and update Attachments 1 and 2 as part of our overall reliability progran.

Performance Specification Review We have reviewed the example performance specification included as an attachment to Enclosure 3 of Generic Letter 84-15 and provided some general comments in Attachment 4.

In sunmary, the performance factor may be more representative of reliability if it is based on additional factors, such as grid stability, in addition to the nunber of failures per demand. The requalification program appears to be more detrimental to the diesel generators due to the excessive number of starts required; and requiring a 7-day surveillance frequency for two unre-lated failures during the past 20 tests also appears excessive.

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ATTACHMENT 1

SUMMARY

OF DIESEL GENERATOR #1 DEMANDS OCCURRING idITHIN THE TIME PERIOD OVER WHICH THE LAST 100 VALID DEMANDS WERE PERFORMED Valid Valid Number Demand /

Reason for Demand / of Suc-Number Fatture D.G. Opera-Failure

  • cessful of Number Da te tion (Yes/No) Demands Failures Analysis of Failure Corrective Action 08/22/84 ' T.S. 3.8.1.1 No N/A 0

1 08/08/84 Su ry. Test Yes 1

0 2

07/11/84 Sury. Test Yes 1

0 3

06/13/84 Sury. Test Yes 1

0 4

05/16/84 Sury. Test Yes 1

0 5

04/18/84 Sury. Test Yes 1

0 6

04/06/84 T.S. 3.8.1.1 Yes 0

1 Upon pushing the #1 D.G. start pushbutton This event was a first time occur-on benchboard Section C, the Diesel Gen-rence and was non-reproducible -

erator start failure alarm came in. On a during Testing. This event has second start attempt, immediatly following. been entered in the OAG's IR/LER the first, the diesel started properly. A ' Tracking and Trending Program.

third start attempt was made approximately Should a second similar event occur one hour later and all systems functioned indicating a possible degradation normally. No exact cause for the start in Diesel Generator Operability, failure could be determined.

corrective action will be taken.

04/05/84 T.S. 3.8.1.1 No N/A 0

7 03/19/84 Sury. Test Yes 1

0 8

02/22/84 Sury. Test Yes 1

0 01/25/84 SIS No N/A 0

3 01/23/84 Sury. Test Yes 1

0 10 12/23/83 Surv. Test Yes 1

0 12/14/83 T.S. 3.8.1.1 No N/A 0

12/02/83 Testing No N/A 0

11 11/25/83 Sury. Test.

Yes 1

0 12 10/27/83 Surv. Test Yes 1

0 13 09/26/83 Su ry. Test Yes 1

0 14 09/14/83 Sury. Test Yes 1

0 15 09/08/83 Sury. Test Yes 1

0 16 08/22/83 Surv. Test Yes 1

0 17 07/22/83 Sury. Test Yes 1

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~ ATTACHMENT 1 Page 2-Valid Valid Number Demand /

Reason for Demand / of Suc-Number -

Failure D.G. Opera-Failure

  • cestful of Number Da te tion (Yes/No) Demands Tailures Analysis of Failure Corrective Action 18 07/06/83 Sury. Test Yes 1

0 19 06/27/83 Sury. Test Yes 1

0 20 05/31/83 Surv. Test Yes 1

0 05/28/83 Loss of 1A No N/A 0

System Station Service Transformer 21

~05/02/83 Sury. Test Yes 1

0 22 04/04/83 Sury. Test Yes 1

0 23 03/07/83 - Sury. Test Yes 1

0 02/12/83 SIS No N/A 0

24 02/07/83 Sury. Test Yes 1

0 25 01/10/83 Sury. Test Yes 1

0 26 01/07/83 Loss of 1A Yes

.1 0

System Station Service Transformer 27 12/13/82 Sury. Test Yes 1

0 28 11/15/82 Sury. Test Yes 1

0 29 10/27/82 Sury. Test Yes 1

0 30 09/29/82 Sury. Test Yes 1

.0 09/19/82 T.S. 3.8.1.1 No

' N/A 0

31 09/06/82 Sury. Test Yes 1

0 32 08/09/82 Sury. Test Yes 1

0 33 07/15/82 Sury. Test Yes 1

0 34 05/24/82 > Sury. Test Yes 1

0 35 06/04/82 Su ry. Test Yes 1

0 36 05/27/82 Surv. Test Yes 1

0 05/26/82 Trouble.

No N/A 1

Diesel did not start on first attempt.

This event occurred in the process shooting of troubleshooting. No corrective actions taken.

05/25/82 Trouble-No N/A 1

Diesel was manually tripped due to low This event occurred in the process shooting lube oil pressure.

of troubleshooting. No corrective actions taken.

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ATTACHMENT 1 Page 3 Valid Valid Number Demand /

Reason for Demand / of Suc-Number Failure D.G. Opera-Failure

  • cessful of Number Da te tion (Yes/No) Demands Fa ilures Analysis of Fa!!ure Corrective Action 05/24/82 Troubleshooting No N/A 1

Output breaker would not close. Two This event occurred in the process attempts were made.

of troubleshooting. No corrective action taken.

37 05/23/82 Sury. Test Yes 0

1 Output breaker IE9 would not close.

Repaired faulty magnetic switch on Attempted to close breaker in pre-frequency generator.

ferred start I and 2.

04/21/82 Test No N/A 0

38 04/09/82 Sury. Test Yes 1

0 39 04/09/82 Sury. Test Yes 0

2 D.G. failed to start on first attempt. Three relays were changed out and 40 Started on second attempt.

D.G.

permanent magnet pick up coils were output breaker failed to close (2 cleaned.

attemots). The problem was determined to be the frequency generator magnet not picking up the SSP 1 Relay, which, in turn, would not pick up MSR 1.

41 03/10/82 Su ry. Test Yes 1

0 42 12/24/81 Surv. Test Yes 1

0 12/12/81 T.S. 3.8.1.1 No N/A 0

12/08/81 T.S. 3.8.1.1 No N/A 0

43 11/26/81 Sury. Test Yes 1

0 44 10/20/81 Sury. Test Yes 1

0 45 10/02/81 Sury. Test Yes 1

0 46 09/04/81 Sury. Test Yes 1

0 47 08/07/81 Sury. Test Yes 1

0 48 07/10/81 Su ry. Tes t Yes 1

0 06/25/81 T.S. 3.8.1.1 No N/A 0

49 06/16/81 Sury. Test Yes 1

0 50 06/08/81 Sury. Test Yes 1

0 51 05/22/81 Sury. Test Yes 1

0 52 04/22/81 Surv. Test Yes 1

0 53 03/22/3' Sury. Test Yes 1

0 54 02/23/81 Surv. Test Yes 1

0 55 01/23/81 Su ry. Test Yes 1

0 56 12/26/80 Sury. Test Yes 1

0 57 11/25/80 Sury. Test Yes 1

0 11/17/80 SIS No N/A 0

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ATTACHMENT 1-Page 4-Valid Valid Number Demand /

Reason for Demand /

of Suc.

Number Failure D.G. Opera-Failure

  • cessful of Number Da te tion (Yes/No) Demands Failures Analysis of Failure Corrective Action 58 10/28/80 Su ry. Test Yes 1

0 59 10/08/80 Sury. Test Yes 1

0 60 09/30/80 Sury. Test Yes 1

0 61 09/20/80 Surv. Test Yes-1 0

62 09/02/80 Sury. Test Yes 1

0 63 08/05/80 Sury. Test Yes 1

0' 64 08/05/80 Sury. Test Yes 0

1 Output breaker E9 failed to close.

The MSR 1 relay block contact was The problem was determined to be cleaned and a spare contact block a dirty contact on the MSR 1 relay was installed in the MSR 1 relay.

which prevented it from sealing in associated auxiliary contacts required to close output breaker E9.

65 07/08/80 Sury. Test Yes 1

0 66 06/23/80 Sury. Test Yes 1

0 06/17/80 Loss of No N/A 1

Diesel did not close on the IAE bus.

At the time of the incident, this IAE Bus This was due to output breaker IE9 Diesel Generator was not being used being in the " Pull to Lock" position as an operable piece of equipment; prior to performing an operability therefore, no corrective actions were OST following design modifications ta ken.

and periodic maintenance.

67 04/25/80 Sury. Test Yes 1

0 68 03/18/80 Surv. Test

.Yes 1

0 69 02/17/80 Sury. Test Yes 1

0 70 02/01/80 Loss of Power Yes 0

1 Failure of the auto load sequencer.

The wiring problem was corrected 'and to the 1A The auto load sequencer was found five manually initiated timer tests Station Ser-to be mis-wired.

were run with satisfactory results.

vice Bus 71 01/22/80 Surv. Test Yes 1

0 72 12/22/79 Sury. Test Yes 1

0 73 12/22/79 24 hr. Load Yes 1

0 Test 74 12/20/79 Sury. Test Yes 1

0 75 11/28/79 Sury. Test Yes 1

0 76 10/31/79 Sury. Test Yes 1

0 77 10/02/79 Sury. Test Yes 1

0 09/20/79 SIS No N/A 0

09/20/79 SIS No N/A 0

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(0 ATTACHMENT 1 Page 5-Valid Valid Number Demand /

Reason for.

Demand / of Suc-Number Failure D.G. Opera.

Failure *.cessful of Number Da te tion (Yes/No) Demands Failures Analysis of Failure Corrective Action 78 09/18/79 Sury. Test Yes 1

0 79 09/04/79 Sury. Test Yes 1

0 80 08/29/79 Sury. Test Yes 1

0 81 08/07/79 Sury. Test Yes 0

1 The second loading sequence was 394 The timer was cycled and adjusted to milliseconds out of specification.

within specifications.

It was determined that the starting point of the sequences was slightly off zero.

82 07/3;/79 Sury. Test Yes 1

0 07/27/79. Test No N/A 0

83 07/24/79 Su ry. Test Yes 0

2 Failure of No. I air start motor.

The pinion assembly was cleaned, 84 The Diesel started on the No. 2.

exercised, and satisfactorily tested.

air start motor. Output breaker No manual start relay contact mis-failed to close. The air start operations were found on visicorder motor failure resulted from a traces taken on 7/31/79. As a result sticking pinion. A test circuit of this incident, the test program installed to monitor breaker con-was revised to 1) monitor the manual trol circuitry indicated the out-start relay coil prior to breaker put breaker failure occurred in operation, and 2) record and alternate the manual start relays.

the position of the start control switch for each manual exercise opera tion.

85 07/10/79 Sury. Test Yes 1

0 86 06/21/79 Sury. Test Yes 1

0 87 06/11/79 Sury. Test Yes 1

0 88 05/29/79 Sury. Test Yes 0

1 High crank case pressure. The Replaced pressure switch.

problem was determined to be caused by a pressure switch which was activated by an air vacuum problem in the D/G room.

89 03/20/79 Sury. Test Yes 1

0 90 03/20/79 Surv. Test Yes 0

1 Output breaker failure. Cause of Checked out relays contacts made for inoperable breaker unknown.

MSRI and VSRI relays - nothing found wrong.

91 02/20/79 Sury. Test Yes 1

0 92 01/23/79 Sury. Test Yes 1

0 01/18/79 SIS No N/A 0

01/03/79 SIS No N/A 0

.go-

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ATTACHMENT 1 Page 6-Valid

. Valid Number Demand /

Reason for Denand/ of Suc-Number Failure D.G. Opera-Failure

  • cessful. of Number Da te tion (Yes/No) Demands Failures Analysis of Failure Corrective Action 93 12/26/78 Sury. Test Yes 1

0 12/08/78 Testing No N/A 0

12/07/78 Testing No N/A 0

12/06/78 Trouble-No N/A 1

  1. 2' Air Start Motor failed.

Installed new motor, shooting 94 12/05/78 Testing Yes N/A l'

. #2 Air Start Motor locked up.

12/05/78 TOP 78-33 No N/A 0

95 11/28/78 Surv. Test Yes 1

0 10/24/78 TOP 78-34 No N/A 0

,10/18/78 TOP 78-34 No N/A 0

10/10/78 TOP 78-34 No N/A 0

96 10/03/78 Sury. Test Yes 1

0 09/25/78 TOP 78-34 No N/A 0

09/19/78 TOP 78-34 No.

N/A 0

09/19/78 TOP 78-33 No N/A 0

97 09/19/78 TOP 78-34 Yes 0

1 Output breaker failed to close.

Retested successfully.

09/12/78 TOP 78-33 No N/A 0

98 09/12/78 TOP 78-34 Yes 0

1 Failure of output breaker to close Approximately one hr. later.

4 attempts were made to paralled another attempt was made to paral-the diesel with the system. '

lel the diesel and troubleshoot, but this time, the output breaker closed. Automatic close-in was then successfully completed.

A-Test panel to monitor the breaker closing contacts was fabricated and installed on 12/8/78.

99 09/05/78 Sury. Test Yes 1

0 100 09/05/78 Sury. Test Yes 0

1 Failure of output breaker to close using the control switch. The breaker was then manually closed.

The diesel generator was then synchronized three times success-fJlly using the control switch.

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~ ATTACtMENT 2 1

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SlMMARY OF DIESEL GENERATOR #2 DEMANDS OCCURRING WITHIN THE TIME PERIOD ~

OVER WHICH THE LAST 100 VALID DEMANDS WERE PERFORMED 1

Valid Valid Number Demand /

Reason for Demand / of Suc-Number Failure

-D.G. Opera-Failure * -cessful of Number Date tion (Yes/No)-Demands Failures Analysis of Failure Corrective Action 1

08/22/84 Surv. Test Yes 1

0 08/22/84 T.S. 3.8.1.1 No N/A 0

2 07/25/84 Sury. Test Yes 1

0 3

06/26/S4 Sury. Test Yes 1

0 4

05/30/84 Sury. Test Yes 1

0 5

05/02/84 Surv. Test Yes 1

0 04/06/84 Testing No N/A 0

04/05/84 Testing No N/A 0

6 04/03/84 Sury. Test Yes 1

0 7

03/05/84 Sury. Test Yes 1

0 8

02/08/84 Surv. Test Yes 1

0 01/25/84 SIS No N/A 0

9 01/11/84 Sury. Test Yes 1

0 10 12/09/83 Surv. Test Yes

-1 0

12/02/83 Testing-No N/A 0

11 11/14/83 Sury. Test Yes 1

0 12 10/14/83 Sury. Test Yes 1

0 09/16/83 Testing No N/A

.0

+

09/15/83 Testing No N/A 0

13 09/12/83 Surv. Test Yes 1

'-0 14 09/08/83 Surw. Test Yes 1

0 15 09/04/83 Surv. Test Yes 0

1 Diesel Generator was shutdown due to No corrective action was' required, high vibrations.

16 08/29/83 Surv. Test Yes 1

0 17 08/27/83 Sury. Test Yes 1

0 18 07/11/83 Sury. Test Yes 1

0 06/29/83 Loss of No N/A 0

1DF Bus 19 06/13/83 Surv. Test Yes 1

0 20 05/24/83 Loss of Yes 1

0 1DF Bus

1 y

1

~

]

+

ATTACHMENT 2 Page 2 Valid Valid Number Demand /

Reason for Demand / of Suc.. Number Failure D.G.. Opera-Failure

  • cessful of Number Da te tion (Yes/No) Demands Failures Analysis of Failure Corrective Action 21 05/16/83. Surv. Test Yes 1

0 22 04/18/83 Surv. Test Yes 1

0 23 03/21/83 Sury. Test Yes 1

0 24 02/21/83 Sury. Test Yes 1

0 02/12/83 515

. No N/A 0

25 01/24/83 Sury. Test Yes

-l' O

26 12/27/83 Sury. Test Yes 1

0 27 11/29/82 Surv. Test Yes 1

0 28 11/01/82 Sury. Test Yes 1

0 29 10/20/82 Sury. Test Yes 1

0 30 10/18/82 Loss of IC Yes 1

0 and ID 4kw busses 31 09/21/82 Sury. Test Yes 1

0 32 09/19/82 Sury. Test Yes 0

1 Diesel shutdown due to engine cooling The heat exchanger tubes were water temperatures exceeding maximum.

cleaned, allowable values. Problem determined to be caused by fouled heat exchanger tubes.

33 08/24/82 Surv. Test Yes 1

0 34 07/29/82 Surv. Test ins 1

0 35 06/03/82 Sury. Test Yes 1

0 36 06/03/82 Sury. Test Yas 1

0 05/31/82 Loss of No N'A 0

480V Sus 37 05/07/S2 Surv. Test Yes 1

0 38 03/04/82 Sury. Test Yes 1

0 39 02/04/82 Sury. Test Yes 1

0 40 01/07/82 Surv. Test Yes 1

0 41 12/10/81 Su ry. Test Yes 1

0 12/08/81 Testing No N/A 0

42 11/12/81 Sury. Test Yes 1

0 43 10/14/81 Sury. Test Yes 1

0 44 09/16/81 Surv. Test Yes 1

0 03/28/81 Testing No N/A 0

08/27/81 Testing No N/A 0

. 'A

7-gOi

}

i i

?

a ATTACHMENT 2

-Pa9e 3 l

Valid Valid Number Demand /

Reason for Demand / of Suc-Number.

l Failure D.G. Opera-

. Failure

  • cessful of l

Mumber Date tion (Yes/No) Demands Failures Analysis of Failure Corrective Action l

l l

45 08/18/81 Surv. Test Yes 1

0

. A l

46 07/22/81 Surv. Test Yes

-1 0

l 47 06/27/81 Surv. Test Yes 1

0 48 06/11/81 Sury. Test Yes 1

0 49 06/32/81 Surv. Test Yes 1

0

.)

l 50 05/03/81 Sury. Test Yes 1

0 51 04/08/81 Sury. Test Yes 1

0 52 03/21/81 Surv. Test Yes 1

0 1

l 53 03/14/81 Sury. Test Yes 1

0 1

54 03/13/81 Sury. Test Yes 1

0 j

55 03/09/81. Sury. Test Yes 0

1 The diesel was brought to speed and The turbocharger and governor tripped, apparently due to overspeed.

taper pin and lever were The diesel would not re-start. The

replaced, failure was attributed to a failed taper pin and bent lever in the governor of the dies 41. The diesel turbocharger also failed.

56 02/09/81 Sury. Test Yes 1

0 57 01/09/81 Sury. Test Yes 1

0 58 12/11/80 Sury. Test Yes 1

0 11/17/80 SIS No N/A 0

59 11/11/80 Surv. Test Yes 1

0 60 10/11/80 Sury. Test Yes 1

0 Replaced two air start motors 61 10/08/80 Sury. Test Yes 0

1 Diesel would not start in the preferred start #2 position. The diesel did on preferred start #2.

start in the preferred start il post-tion.

62 09/04/80 Sury. Test Yes 1

0 63 07/18/80 Sury. Test Yes 0

1 Discharge pressure on fuel transfer Inspected, cleaned and reset 07/09/80 Testing No N/A 0

. relief valve.

pump EE-p-ID not acceptable.

06/07/B0 Tornado No N/A 0

Watch 64 05/27/80 Surv. Test Yes 1

0

4-k w

A w-

N

.-g.

a.

m

' ATTACHMENT 2 Page 4 Valid Valid Number Demand /

Reason for Demand / of Suc-Number Failure D.G. Opera-Failure

  • cessful of Number Da te tion (Yes/No) Demands ' Failures Analysis of Failure '

Corrective Action 65 04/29/80 Sury. Test

.Yes 0

1 Test terminated due to a minor problem Replaced PT fuse, with phase balance voltage and a blown -

PT fuse alarm.

66 04/29/80 Sury. Test Yes 1

0 67 04/01/80 Surv. Test Yes 1

0 68 03/04/80 Sury. Test Yes 1

0 69 02/05/80 Sury.- Test Yes 1

0 70 01/08/80 Sury. Test Yes 1-0

. 71 12/11/79 24 hr. Load Yes 1

0 Test 09/20/79 SIS No N/A 0

09/20/79 SIS No N/A 0

72 08/09/79 Sury. Test Yes 1

0 73 07/24/79 Sury. Test Yes 1

0 74 07/10/79 Surv. Test Yet 1

0 75 06/29/79 Sury. Test Yes 1

0 76 06/02/79 Sury. Test Yes 1

0 77 05/01/79 Surv. Test Yes 1

0 78 G4/13/79 Sury. Test Yes 1

0 79 04/03/79 Sury. Test Yes 1

1 Diesel would not start by engaging the Both air start motors on the.

80 No. 2 set of starting motors; it

" Start 2" system were replaced appeared that the carbon vanes in the with new air motors.

air motors failed or were damaged.

The diesel was started with the No. I set of starting motors and a full surveillance test was performed.

81 03/06/79 Sury. Test Yes 1

0 82 02/06/79 Surv. Test Yes 1

0 01/18/79 SIS No N/A 0

83 01/09/79 Surv. Test Yes 1

0 01/03/79 515 No N/A 0

12/08/78 Testing

-No N/A 0

84 12/04/78 Surv. Test Yes 1

0 12/04/78 Testing No N/A 0

85 12/04/78 Testing Yes 0

1 Field flash breaker failed to close.

Corrected relay problem.

Found FFC0 Relay dropped out.

86 12/04/78 Sury. Test Yes 1

0

0 6

-(6 ATTACHMENT 2 '

Page 5

~

Valid Valid' Number Demand /-

Reason for

. Danand/ - of Suc-.

Number-Failure D.G. Opera.-

Fa ilure* cessful of-Number Da te tion (Yes/No) Demands -Failures Analysis of Failure Corrective Action 87 12/01/78 Sury. Test ~

Yes, 1

0 88 -

11/06/78 Sury. Test Yes 1

0

,10/25/78 TOP 78-36 No N/A 0

~

89

.10/25/78 TOP 78-36 Yes 0

1 Generator field failed to flash. Diesel taken out of service.

~

08/29/78 - Trouble-

.No

.N/A 0

Troubleshooting output bresker (IF9)

. Installed output breaker trouble-shooting shooting circuit to DG#2.

90 08/24/78 Sury. Test ies 0

I Failure of output breaker to close.

The breaker was cycled in the test i

position and it operated correctly.

Another attempt was made to close the breaker, but it would not close from the benchboard. No apparent cause for failure.

91 08/22/78 Sury. Test

_Yes 1

.0 92' 07/28/78 "45 Yes 0

1 Field flash relay failure. The field A remote generator field flash was manually flashed. The field flash contr:1 has been installed in failures have been attributed to an the contrci room to manually intermittently sticking field flash flash the diesel generatce field, cutout relay.

' This control bypasses the field flash cutout relay to insure field flashing in an energency.

93 07/25/78 Surv. Test Yes I.

0 r

94 06/30/78 Sury. Test Yes l'

O 95 06/30/78 Sury. Test Yes 0

1 Trip of field flash breaker.

Checked fuses, reset breakers,

^

checked DC voltage - All OK.

96 06/07/78 Sury. Test Yes.

1 0

97 06/01/78 Sury. Test Yes

-1 0

98 06/01/78 Sury. Test Yes

-0 1

Diesel was shut down due to a lube The swagelock was assembled and oil leak in the engine control panel.

tightened.

An inspection of the lines revealed that the leak was due.to a loose swagelock fitting which had not been tightened following previous mainten-ance.

99 05/02/78 Sury. Test Yes 1

~

0 100 05/02/78 Surv. Test Yes 0

1 Generator field failed to flash.

Retested DG #2 and the field flash operated properly.

  • Test Qualification determined by Regulatory Gaide 1.108, position C.2.e criteria.

ATTACHMENT 3 DIESEL GENERATOR DESIGN CHANGES The following design changes have been or are planned for implementation at Beaver Valley Unit 1 to improve diesel generator reliability.

Design Change Design Change Proposal #

Summary of Design Change Status DCP #025 The diesel generator air drain tanks Complete were upgraded from 150 psig to 275 psig improving the efficiency in which the receiver tanks are blown down.

DCP #042 The ability to manually synchronize the 4R 4160V Bnergency Busses to normal busses is being added. This feature enables synchronizing busses without dropping the energency bus load or the diesel generator feed. This design change also prevented the possibility of simultaneously connecting more than one potential transformer voltage to an incoming or running synchronizing bus.

DCP.f124 The NFLD control relay contact has Complete been permanently disconnected. Prior to this change,.the relay caused tripping of the diesel generator output breaker for loss of field when operating in both the energency and exercise modes. Loss of field protection of the diesel generators still exists during the exercise mode.

DCP #142 Modifications have been made to the Complete diesel generator alarms in the control room to verify the system operates within the required system parameters.

DCP #157 The diesel generator output breaker's Complete control circuitry has been provided with new undervoltage relays which prevent the 4160V breakers from closing if the genera-tor does not have a functioning field.

D f

n

' ~

ATTACHMENT 3 Page 2 Design Change Design Change Proposal #

Summary of Desian Change Status DCP #180-

- Motor. control centers have been installed Complete so that there is no loss of generating capability when the #1 and #2 vital bus 4

inverters are out of service, bypassed or if offsite power is lost.

In addition, four~ AC relays have been replaced with DC relays providing more reliable power supplies:to the sequencing circuits.

- DCP #223 The ability to manually flash the diesel Complete generator field has been provided.

L DCP #337 The replacement of two cams programmers Complete

~

and the installation of test switches 1

-in the coil. input and contact output of each cam programer allows verification that the operation of the cam program e

timer is within the contact acceptance 1

- criteria.

DCP.f340 The addition of isolation valves to the Complete engine control. panel pressure gages and thennowells to the coolant and lube oil temperature indicators allows the removal of the gages for calibration without removing the diesel generators from service.

DCP #390 A.new 8000 gallon fuel-oil storage Complete tank was installed as a. holding reservoir while tests (Regulatory e

Guide 1.137) are performed. An alternate method of level. indication has been provided to the existing fuel oil storage tanks to ensure the accuracy of the

. existing level indicators.

DCP'#443

' To prevent control circuit failure Complete due to DC coil supply voltage variations, the "No voltage" relays were-replaced with a qualified equivalent unit having a sufficient DC rating for the DC supply voltage range experienced.at BVPS.

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ATTACHMENT 3 Page 3 Design Change Design Change Proposal #

Summary of Design Change Status DCP #452 As a result of the March 1981 failure Complete of one diesel generator due to turbo-charger problems, several vendor-recommended product modifications were implemented to improve reliability and perfomance.

Included were turbo-charger gear ratio change from 18:1 to 17.9:1 and a second auxiliary lube oil pump.

DCP #458 Air compressor modifications were made Complete by adding unions in the piping to facilitate maintenance of the air compressor discharge valves.

DCP #478 The air start compressor check valves Replace as were replaced with new horizontal fail piston type check valves.

DCP #556 To ensure continuity of electrical 4R power in the event of a plant fire and concurrent loss of electrical power, relays and cables currently in the same fire area have been separated into different fire areas.

DCP #576 In order to simplify and streamline the 1984 air start compressors the centrifugal unloader, pilot valve and relief line have been eliminated. Also additional check valves have been added in series with existing check valves.

l~

DCP #560 To prevent all four motor-operated diesel Complete generator river water supply inlet valves, which are located in the same fire area, from being rendered inoperable because of fire, a new valve has been installed in another fire area. One of the supply inlet valves is now in a pemanently locked open position.

l --

DCP #601 Due to corrosion of the trim of the relief 4R valves for the air starting system, the relief valves have been replaced by valves constructed of standard material witi. type 316 stainless steel trim.

t-I b

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ATTACHMENT 3 Page 4 Design Change Design Change

- Proposal #

Summary of Design Change Status DCP #652 To prevent failures that may occur due to To be implemented dirty, corroded or pitted relay contacts by sixth refuel-the diesel generator excitation cabinets ing will be modified to provide a dust free environment.

This is to be accomplished by providing gaskets on the front doors, filters on louvers, and an air-tight seal on the cable trench beneath the cabinet.

DCP #614 Permanent breaker test circuits have 1985 been installed to make diesel generator breaker testing more efficient.

1 m

ATTACHMENT 4 General Comments on Example Performance Specification 1.

The test frequencies and allowable out-of-service intervals for diesel generators should be based not only on the number of failures per demand but include items such as:

a.

related failures occurring with the past (100) tests.

b.

historical grid stability where:

(i) partial losses of offsite power should not be weighted as heavily as complete losses of offsite power (ii) the duration of the events should also be a consideration.

c.

the time the diesel generator is out-of-service for maintenance during a required mode.

We believe that this type of methology would be more responsive in addressing USI A-44 because it would provide additional incentives for Licensees to improve their overall performance in many aspects associated with blackout events.

This would also insure that all service-related factors affecting the diesel, such as operating, maintenance practices and environmental conditions, are evaluated to enhance reliability of both IE and non-IE power systems.

2.

We do not believe that the diesel requalification program, as presented, is usable because a diesel generator could be unnecessarily placed into a requalification program due to conditions external to and unrelated to its specific performance.

For example, the failure of the generator output breaker to close due to a mechanical breaker problem or relay failure could force requalification of the entire diesel generator and place unnecessary cycles on the entire system.

We believe that-the source of any recurrent failure (s) should be requalified where possible and not force disqualification and requalification of the entire diesel system unless the failure is strictly associated with degraded engine or generator performance.

In addition, the requalification program does not address load shedding and sequencing as these are vital aspects to diesel generator reliability.

However, having to requalify this function during power operation would decrease overall plant reliability by causing safety syste.m challenges.

In summary, we believe that requiring seven demands within 20 days and fourteen demands in 75 days will increase degradation of the system and the program may not verify operability of the source (root cause) of the failures.

k.

i Page 2 3.

The example performance specification (item 3.b) indicates, "two failures in the last 20 demands may only be a statistically probable distribution of two random events".

For this reason, we believe that two failures in 20 demands does not justify a seven-day surveillance frequency unless the i

two failures are related.

l 4.

We concur with the NRC's determination that the out-of-service time i

should be in excess of the current 72-hour Technical Specification limit (item 7) and for a cumulative outage time, we recommend that licensees

)

responses to NUREG-0737 item II.K.3.17 on ECCS - outages be consulted.

A i

flexible cumulative outage time based on grid stability, diesel generator failure history,. and manufacture recommended preventative maintenance appears more appropriate than a fixed time.

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