ML18064A406

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LER 94-017-00:on 940902,EDG 1-1 Maximum Output Was Below Maximum Required Design Basis Load.Caused by Inadequate Design Basis Testing.Edgs Will Be Periodic Peak Load Tested. W/941003 Ltr
ML18064A406
Person / Time
Site: Palisades Entergy icon.png
Issue date: 10/03/1994
From: Gire P, Rogers D
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-94-017, LER-94-17, NUDOCS 9410110209
Download: ML18064A406 (16)
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Text

. ;",,

consumers Power David W. Rogers Plant Safety and Licensing Director POWERINli

. MICHlliAN"S *PROliRESS Palisades Nuclear Plant:_ .27780 Blue Star Memorial Highway, Covert, Ml 49043 October. 3, 1994 Nuclear Regulatory Commission ATTN: Document Control Desk Washington, oc 20555 DOCKET 50-255 - LICENSE DPR-20 PALISADES PLANT LICENSEE EVENT REPORT 94~017 Li~ensee Event Report (LER) 94~017 is attached. This event i~ report~ble to the NRC per 10CFR50.73(a)(2}(ii){B) as a condition outside the design b~sis of t_he plant.

SUMMARY

OF COMMITMENTS .

This LER contains seven new commitments summarized below. Palisades will also p~ovide a supplement to this LE~ containing an engineering eva]uation of the past operability of the IDGs with their reduced load carrying tapabil it i es.

1. Complete short-duration peak load tests for both EOGs during the next two monthly tests. The monthly testing will monitor engirie performance and establish trend information, pertaining to fuel rack positiqn relative to KW loading, at loads of 2300 KW and above.
2. Upon the completion of Action 1, (monthly peak load testing}, est~blish operability criteria in the*monthly EOG test. procedures to ensure that EOG load carrying capability for design basis loads is verified. At this time it is anticipated that available fuel fack travel at a gi~eti load, with a known correlation between available travel and load output, will provide an accurate method to monitor design basis capabilities.
3. Establish periodic design basis testing for both EDGs. The anti~ipated testing interval is once each refueling cycle, and ~ill be base~ on the results from the trending and testing from Actions 1 and 2.

9410110209 941003 PDR ADOCK 05000255 S PDR A CM5 ENERGY COMPANY

2 .

4. Determine the root cause for the apparent minor engine degradation that has occured on EOG 1-1 with respect to the original 1969 engine testing. Enhance the present performance monitoring program for the EDGs to m~intain the engines at or near peak performarice .

. 5. Establish preventative maintenance controls to periodically monitor engine gov~rnor performance and coritrol setpoints to ensure governors .

  • perform as expected in both "Parallel" and "Unit" modes.
6. Establish administrative controls to ensure that changes to the plant design basis that occur*through analysis are properly controlled and

~valuated for potential verification testing.* *

  • 7. Evaluate the design marg~n that exists for both EDGs with respect' to the maximum accident requtred loads and determine the possible alternatives that exist to increase *the margin ..

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-c:::5'. *J David W. Rogers Plarit Safety* and Licensing Director C-C Admi°nistrator, Region III, USNRC NRC Resident Inspector - Palisadei Attachment

NRC Form 366 .u:s. NUCLEAR REGULATORY COMMISSION*

19-831 APPROVED OMS NO .. 3160*0.104' EXPIRES: 8/31 /86 LICENSEE EVENT REPORT (LERI FACILITY NAME .(1) DOCKET NUMBER (2) PAGE 131 Palisades Plant 0 5 0 0 0 2 5 5 1

  • OF 8 TITLE 141 Inoperable Diesel Generator Due To Inability To Fully Supply M*aximum Analyzed Electrical Power Demand During A Postulated Design Basis Accident.*

EVENT DATE (61 LER NUMBER (61 'REPORT DATE (6) OTHER FACILITIES INVOLVED (8)

REVISION FACILITY NAMES MONTH DAY ...YEAR YEAR NUMBER MONTH DAY YEAR N/A *. 0 6 0 0 0 0 9 0 2 9 4 9 4 0 1 7 00100394 N/A 0 6 0 0 0 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR t: /Ch<<k °""or more of thfJ folkJwingJ (111 .

OPERATING N 1--~2-0-.4-02-lb-l-------------.----.,....-20-.4-0-61-cl-----------....--,..--60-.7-3-(*-ll2-ll-ivl----------..--..-7-3-.7-1(-bl--------......,...---1 MODE (91 20.40611111 llil 60.36fcll11 60.73(*112llvl 73.71fcl 20.406(o)(1 )(iil 60.36(c)(2)

  • 60.73(*1121lviil OTHER (Specify in Abat;oct 20.4061*111 lliiil 60.73(*1121lil 60.73foll2UviiillAI ~low and in TeXt *.

20.406(o)(1 llivl X 60.73foll21liil S0.73(o){2){viiiilBI NRC Form 386Al 20.406(oll1 llvl 60.73f*ll21liiil_ 60.73foll21lxl LICENSEE CONTACT FOR THIS LER (121 NAME TELEPHONE NUMBER AREA CODE Paul J. Gire, Staff Licensing_ Engineer 6 7 .6 4 8 9 MANUFAC* REPORTABLE MANUFAC* REPORTABLE

, .. CAUSE SYSTEM* COMPOl;o!ENT TUR ER To NPRDS CAUSE SYSTEM COMPONENT TUR ER

  • ~

SUPPLEMENTAL REPORT EXPECTED (141 *MONTH DAY YEAR EXPECTED SUBMISSION X YES Uf yes, comp/ate CXPECTED SUBM/SsJON DATEJ NO DATE(16l 1 .1 2 3 9 4 ABSTRACT /Umit to 1400 spaCes, i.e. approximately fift**.n single-space typewritten lines) 116)

On September 2, 1994, while the plant was operating_ at 100% power, and during maintenance testing,-it was discovered that the Emergency Diesel Generator 1-1 (EOG .1-1) maximum output was below the maximum required design bas1s_load. A misadjusted engine governor output * * .

linkage and engine performance degradation limited the EOG 1-1 output. The engine problems were corrected and an electrical load test was completed on September 4, 1994 to verify design basis maximum load carrying capability. A similiar load test and. minor linkage adjustn:1ents were _

completed for the alternate EOG 1-2 on September 7, *1994. The as-found road ca,rrymg *

  • capability of the EOG 1-2 was found slightly below the maximum analyzed design basis load.

The causes for .this event were inadequate design basis testing, failure to effectively monitor for engine performance degradation, and failure to adequately control modifications made to engine governors in the past. * **

  • Corrective actions for this event include periodic peak load testing for EDGs, and enhanced EOG performance monitoring, to include engine governor performance. . *

. . NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION (9*83) APPROVED OMB NO. 3160-0104 EXPIRES: B/31 /86 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME 111 DOCKET NUMBER (2) LEA NUMBER 131 PAGE (4)

SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant Q 5 Q . Q .Q 2 5 5 9 4 - Q 1 7 - Q Q Q 2 OF Q 8 Event Descripti.on On September 2, 1994, while the plant was operating at 100% power, and during maintenance testing, it was determined that the Emergency Diesel Generator 1-1 (EDG 1-1), [EK], was

  • incapable of supplying the maximum analyzed design basis load. A misadjusted engine governor output linkage and engine performance dearadation combined to limit the EDG 1-1 output to .*
  • below the maximum analyzed load, which 1s elevated for the first half hour period after a large break loss of coolant accident. An engine tune-up -and fuel linkage adjustments were completed and followed by a design* basis load test on September 4, 1994. The test verified design basis*

maximum load. carrying capability. A similiar load test and minor linkage adjustments were completed for the alternate EDG 1..:2 on September 7, 1994.

  • The as-found load carrying
  • capability of the EDG 1-2 was equal to the maximum analyzed design basis load. However, when instrument inaccuracies are factored into the comparison, the EDG 1-2 performance was 12 KW below the analyzed load demar)d.
  • The diesel engines were restored to operable status within the Technical Specification allowed equipment outage period. The reactor remained at 100% power during the testing and repairs.

Due to the fact that the EDG 1-1 has been incapable of performing its full design function for a significant period, this event is reportable in accordance .with 10CFR50.73(a)(2)(ii)(B) as a

  • condition outside the design basis. There. have been times recently when EDG 1-2 has been taken out of service for maintenance and testing. Thus, during these times both emergency diesel
  • Cause Of The Event The cause of the event was the failure to verify design basis functional requirements for the EDGs. Beginning in 1986, the analyzed peak accident loads surpassed the continuous load rating
  • of 2500 KW for both EDGs. During this period, implications of the peak loading values were evaluated. Load testing above the continuous rating of the engine was considered potentially *.

damaging to the engines, and ori9inal vendor testing in 1969 had verified peak load capabilities.

Also, monthly _testin~l at the continuous rated load of 2500 KW appeared to provide appropriate performance monitoring.' This evaluation was not totally correct, and was not appropriately con.servative. to provide the ultimat~ assurance that the. EDGs were capable of ~erforming t~eir design function.** A current evaluation of peak load testing has determined that infrequent diesel operation at elevated loads is acceptable as well as necessary to verify EDG capabilities. * .

Other SiQ~ific~nt contributors. to this event are: 1) a failure to adeguately control maintenance and modif1cat1ons on the engine governors and associated output linkage to ensure changes would not inadvertantly limit load carrying capability, and 2) a failure to recognize that subtle

  • . engine performance degradation was occurinQ on EDG 1-1 and reducing the margin that is* *
  • available for engine output above. design requirements. *
  • NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION 19*831 APPROVED OMB NO. 3160-0104 EXPIRES: 8/31/86
  • LICENSEE EVENT REPORT ILER) TEXT CONTINUATION FACILITY NAME 111 DOCKET NUMBER 121 LER NUMBER 131 PAGE 141 SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant 0 5 0 0 0. 2 5 5 9 4 - 0 1 7 - 0 0 0 3
  • OF 0 8 Analysis Of The Event *

.Accident Load Analysis History Palisades has two independent and redundant emergency EDGs with continuous load ratings of 2500 KW and two hour maximum load ratings of 2750 KW. (Refer to FiQure 1 which summarizes*

EOG.loading informati~n.) Technical Specification Surveillance T~st requirements have always .. *'.

required monthly starting and load testing at 2400 KW *plus or .mmus. lOO KW. * . . * .*

Beginning in 1986, as a result of plant modifications, the maximum* analyzed accident loads * * *~

required to be supplied by the EDGs after a design basis accident exceeded. their continuous re;1ting of 2500 KW. However, the load test requirements for the EDGs remained at 2400 pl'us or minus .

. 100 KW. (Refer to Figure 2 for the historical depiction of maximum analyzed EOG loads.) At that time, peak load testing .of the EDGs was considered potentially damaging to the engines, and also.

Plant Technical Specifications, Section 4.7.1.d., restricted loading of the EDGs to below 2500 **

KW. Presently, the maximum analyzed loads required to be supplied by the EDGs are 2688 KW

  • for EDG 1-1 and 2663 KW for EOG 1-2. Also the Plant Technical Specifications, Section *
4. 7 .1.d., was .revised in 1987 to. clarify the diesel load restriction to 750 amps at 240.0 volts~

~**

Discovery Of The Problem " * :'l The first indication of a EDG load capability problem occurred during routine monthly testing of EDG 1:.:t on July 19, 1994. The maximum output of the engine was ..unexpectedly limited to 2340 KW, (acceptable range is 2~00 to 2500 KW). Operations personnel attempted to load the engine to the nominal test load of 2400 KW. However, the electrical governor*upper limit . *.

prevented further loa~ing. A prompt operability evalu~_tion was completed at this time and the EOG 1-1 was determined to be operable. The operability call was based on the fact that the .

design basis function of the engine is to provide emergency power to safety related components in the "Unit" mode. Monthly engine testing is only performed in the "Parallel" mode, which is

  • with the engine paralleled to the electrical grid; The load carrying capability of the engine in the *

"Unit" mode is not affected bY, the electrical governor upper limit, which provides a control .

function solely in the "Parallel' mode. The engine performance data was also reviewed at this time and all parameters were normal. System Engineers and Operations personnel were . *.

convinced that the condition only affected the load carrying capability durina testing, and that the upper li'!lit simply. needed adjustment. This would all~vy future monthly .t~sting to be performed at the higher nominal test value of 2400 KW. A cond1t1on report was 1rnt1ated to document the

  • operability call and provide for further control and review of the electrical governor limit
  • adjustment.
  • On July 29, 1994, EOG 1-1 was removed from service to complete* the adjustments to the electrical governor limits and to gather additional testing data. *.The :upper limit could not be .
  • complet~ly adjusted due to une?Cpec~ed interfei'!3nce from the speed control s~tting of t~e . . . ...

mechanical governor. The partial ad1ustment did allow the EDG 1-1 to be loaded to an improved value of 2400 KW. Also, several other findings from the ongoing evaluation continued to support the initial conclusion that the reduced loading capabilities were associated solely with the "Parallel" mode of operation. Specifically, the speed droop setting was incorrect for the EDG 1-1, which limited its output in the "Parallel" mode. Also, an additional 3/16" of engine fuel rack .

travel was measured at the 2400 KW loading and would supposedly be availabfe in "Unit"

,_, , . ....-..------....,-------4 NRC*Form 366A U.S. NUCLEAR REGULATORY COMMISSION (9-8:il APPROVED OMB NO: 31S0-0104

  • ~-.* EXPIRES: 8/31 /86 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LEA NUMBER (31 PAGE (41 SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant 0500025594-() 1 7 0 0. 0 4 OF 0 8 mode for EOG 1'-1 to provide the additional accident loading required. Further planning was required to make the final adjustments to all of the engine governor settings.

On Au.gust 30, 1.994, the EOG 1-1 was removed from service and planned adjustments were

.made to the electrical and mechanical governors. The adjustments improved the EOG 1-1 output to 2438 KW, but at this time it became aprarent that the governor settings were no longer .

  • limiting the engine output. The mechanica . governor output shaft was found to be at its full ~

travel. The results of this test were unexpected and indicated that the engine capability in both

. "Parallel" and "Unit" modes was mechanically limited to the 2438 KW value. Additional

  • instrumentation was used during this testing to ensure that accurate load indications were being obtained. The EOG l-1 was declared. inoperable, and a troubleshooting team was organized to determine the root cause for the r~duced load carrying capability.
  • The troubleshooting on EOG 1-1 resulted in the discovery that fuel rack linkage conf.iguration was improperly limitin9 full r<;1ck travel and, thus, .there was available engine output that could be gamed by correcting this.problem. Initial adjustments of the linkages were :completed, to allow the engine to supply up to 2500 KW, and further adjustments would be needed during a planned design basis test that was under development. Also, it became apparent that the engine ..
  • performance had degraded because it was not providing the expected power output at the
  • measured fuel rack travel, with respect to the* original vendor test data from 1969. Inspections, adjustments, and replacement of suspected components provided minor improvements i_n engine.

performance, *but no specific component degradation was found .to explain the lower engine .

. output.* * *

  • On .~eptember 3, 1994, the initial.desigrYbasis load test was performed for::*eoG l:..i .and the. * *
  • maximum 'Output was measured at ~685 KW. Based on the results of the test and observation of the fuel rack positioning, further rack adjustments and testing was completed until full rack travel
  • .**resulted in an output of 2714 KW. This value includes an instrument inaccuracy penalty. of 17 KW. The fuel rack linkage adjustments appear to have resulted in the majority of the total
  • performance improvement (276 KW) that was gained during the troubleshooting and repairs: ..

Based upon review of the final test results, the EOG 1-1 was declared operable on

  • September 5, 1994. * * *
  • On September 7, 1994~ a design basis load test was performed for the alternate EOG 1-2 to verify its ability to supply maximum analyzed loads. The as-found load carrying capability of the EOG 1-2 was 2651 KW, which includes a 15 KW instrument inaccuracy penalty. This as-found performance was* 1 2 KW below the maximum analyzed design basis load of 2663 Kw*. The root cause for the EOG 1-'2 reduced load carrying capability was an improperly positioned fuel rack travel hard-stop. The hard-stop was adjusted and a second peak load test was performed. An improved output of 2697 KW was recorded during the test, which includes an instrument .

inaccuracy penalty. During the second EOG 1-2 peak load* test, the electrical grid was unstable

  • and thus the load out8ut of the EOG 1-2 was unsteady. The engine output was observed at
  • times to be over 275 KW. Thus, the current actual maximum output for the EOG 1:.2 is higher than the Value recorded in the test. The EOG 1-2 was declared operable on September 8, 1994,
  • based on its ability to provide the maximum design basis load. Future peak load tests for EOG 1-2 will provide additional data to determine a more accurate engine maximum output value. . *

.. ** ~  ; .**.- -.*.

  • 19*831 APPROVED OMB NO. 3160-0104.

EXPIRES: 8131186 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME 111 DOCKET NUMBER 121 LEA NUMBER 131 PAGE 141 - *.~

.SEQUENTIAL REVISION YEAR . NUMBER NUMBER Palisades Plant 0 5 0 0 (j 2 5 5 9 4 - 0 , 7 - 0 0 OF 0 8 Several maintenance and modification activities from the 1970s and 1980s are primarily * .

, responsible for the reduction in peak load carrying capability below the initial 2800 KW for both EOGs-. The mechanical governor was replaced on EOG 1-1 iii 1979 and again in 1982. The .

electrical governor was replaced on EOG 1-1 in 1989. Similarily,*the mechanical governor was replaced on the EOG 1-2 in the early 1980s.

  • It is* suspected that, during the governor .

modification work, output linka9e misadjustments occurred that limited the engine output to a value below the original capability of 2800 KW, but .still above the 2500 KW rating. The impact upon the total load carrying capability of the engines remained l!ndetected at that time due to the existing operability test cr_iteria of 2400 KW, plus or minus 100 KW. _ . .

The EOG 1-1 engine performance degradation issue remains under investigation at this time. The pres_ent maximum output. of EOG 1- l is approximately 100 KW below the original vendor testing results from 1969. Also, the present maximum output was obtained at a fuel rack position

  • slightly beyond the position recorded in the original vendor test. *There are possible unknown testi~g coi:ifiguration differences between the ori.ginal vendor testing and our present.testing .

conf1gurat1on. These differences may have provided a reduced back-pressure or other advantage during.-the original testing. . * . . ,  : * .* .*

Safety *Significance.

The inability of the EOGs* to provide the maximum analyzed accident loading is of considerable safety significance. A detailed engineering analysis of the impact of reduced load carrying

  • capability is in progress, and has not been completed yet. The final analysis will be provided in a .

supplement to this LER. However, a preliminary evaluation of the EOG 1-1 degraded. performance

  • has determined that the engine would have remained running and performed its safety function in .

a degraded mode. This result is based on the fact tbat significant conservatism exists in the load .

analysis, and the engine and associated generator possess inherent design ruggedness. Thf?

preliminary evaluation has also determined that the individual safety related loads on the EOG

  • supplied safety buses would remain running ahd provide their design function at the anticipated reduced flow rates. EOG* 1-2 output was only s_lightly below the maximum accident load and, thus, its performance will also be shown to be adequate to provide.its safety function. * . *"

The EOG design basis accident load profile is a depiction of the postulated electrical load that w.ill exist at a certain time after a worst case design basis accident. The accident load profile is a combination of the automatically sequenced loads and any operator manually initiated loads *.

allowed by our Emergency Operating Procedures,(EOPs) .. (FiQures 3 through 6 provide the present versions of accident loading profiles, as well as proposed revised versions for both EOGs.) .The

. difference between the present version and the proposed version is a timing change for the *

.initiation of control room ventilation condensing units and containment hydro9en recombiners. . ..

The present version assumes that the two mentioned loads are initiated at thirty minutes after the start of the event, while the. proposed version assumes that the loads are initiated at sixty minutes from the start of the event. The two manually initiated loads are conservatively placed in the

  • present load profiles well in advance of their need; and also well in advance of their realistic starting times during the initial stages of an accident. Thus, the present versions of EOG loading
  • profiles contain approximately 104 KW of conservatism at the critical thirty minute period after
  • the start of the event. The anticipated reduction in the actual loadin9 will not be factored into this evaluation because current EOPs do not restrict the manual loading from occurrinQ at the

-earlier time. The difference between the present load profile and the proposed profile 1s

  • NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION 19-831 APPROVEO OMB NO. 3160-0104 EXPIR.ES: 8/31 /86 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME 11! DOCKET NUMBER 121 LER NUMBER 13! PAGE 141 . - *- , ----

SEQUENTIAL REVISION YEAR NUMBER NUMBER

  • Palisades Plant o s o o o 2 s s s 4 - o 1 1 - o *o 6 OF 0 8

.* ... considered as conservative margin that exists to be considered in the total overview of this issue.

-Future EOP changes can permit this margin to be reflected in the official load profiles. .

capability and its impact on:

1. Steady state operation of the engine and its .supplied loads at a reduced frequency, and the impact upon the nuclear fuel arid containment building parameters due to the reduced safety related pump and fan flows. ** . - * . .

2 .. Short time. operation of the engine during the transient loading periods when the electrical loads are placed on the safety bus and tile engine must accept the transient load. demands.

EOG 1-1 was capable:*of providing 2438 KW, as determined by the special peak load test .* .

completed on September 5, 1994.

  • From Figure 3, shown below, is the present analyzed load that the EOG 1-1 must provide immediately following the worst case design basis accident:

TIME PERIOD AFTER OBA EVENT. MINUTES ANALYZED LOAD, KW

... 0 TO 2 MINUTES 2556 KW

  • 2 TO 20 MINUTES 2573 KW

.: 20 TO 30 MINUTES 2537 KW 30 TO 32 MINUTES 2688 KW 32 TO 60 MINUTES 2397 KW BEYOND 60 MINUTES . 2457 KW

.* EOG 1-1 would not have been capable of supplying the steady state* loads, af an operating * *

  • frequency of 60 hertz, during the first 32 minutes following the design basis accident. The engine would reduce in speed, which would result in a reduction in system operating frequency for the connected 2400 and 480 volt loads. A reduction in operating frequency will directly affect connected motor speeds for pumps anc:J fans. The component supplied flows will be .

reduced, which in turn will result in lower KW loading on the EOG. The exact reduced KW loading is difficult to determine since the connected loads will not all react the same to the reduction in system frequency. The final engineering evaluation will be provided in a supplement to this LER and will include the impact upon the accident analysis with the reduced pump and fan flows.

' V' PAST 'OPERABILITY OF EOG 1-2 EOG 1-2 was capable of providing 2651 KW, as determined by the special peak load test*

completed on September 7, 1994. From Figure 5, shown below, is the present analyzed load that the EOG 1-2 must provide immediately following the worst case design basis accident: - .

NAC Form 366A . U.S. NUCLEAR REGULATORY COMMISSION (9*83) APPROVED OMB NO. 3160-0104

  • ~~-. EXPIRES: 8/31 /86 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAME 111 DOCKET NUMBER 121 LEA NUMBER 131 PAGE 141 SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant Q 5 Q Q .Q 2 5 5 9 4 - Q 1. 7 - Q Q Q 7 OF Q 8 TIME PERIOD AFTER OBA EVENT. MINUTES. ANALYZED LOAD KW 0 TO 2 MINUTES 2471 KW 2 T0*30 MINUTES 2502 KW 30 TO 40 MINUTES . 2663KW 40 TO 60 MINUTES 2366 KW.

BEYOND. 60 MINUTES 2426 KW The as-found capability of the EDG 1-2 exceeds the required loading, except for the ten minute

  • period from 30 to 40 minutes when the analyzed loading peaks at 2663 KW. Since the engine
  • could not supply the steady state load of 2663 KW at an operating frequency of 60 hertz, the engine would reduce in speed to approximately 59.8 hertz during fhis ten minute period.* The .

. EDG 1-2 case is bounded by the situation for the EDG 1-1 .

  • The impact of slightly reduced .*

.frequency and associated safety related pump and fan reduced flows is minimal for the EDG 1-2 case. The . final engineering evaluation . will also cover the EOG* 1-2 case.

Corrective Action

*Corrective action for this event includes the following actions:
1. *Complete short-durati.on peak toad tests for both EDGs during the next two monthly *tests.

The monthly testing will monitor engine performance and establish trend information,

  • perta*ining to fuel rack position relative to KW loading, at loads of 2300 KW and above. ,
2. Upon the completion of Action 1, (monthiy peak load testing}, establish operability criteria **

in the monthly EOG test procedures to ensure that EOG load carrying capability for design basis loads is verified. At this time it is anticipated that available fuel rack travel at a given toad, with a known correlation between available travel and load output; will provide an accurate method to monitor design basis capabilities.

  • 3..
  • Establish periodic design basis testing for both EDGs. The 'anticipated testing interval is

.once eac~ refueling cycle, and will be. based on the results from:the trendin_g and testing from Actions 1 and 2. * * . . *

4. Determine the root cause for the aprarent minor engine degradation that has occured on EDG 1-1 with respect to the origina 1969 engine testinQ: Enhance the present .
  • performance monitoring program for the EDGs to maintain the engines at or near peak
  • performance. .
5. Establish preventative maintenance controls to periodically monitor engine governor
  • ~erformance and control setpoints to ensure governors perform as expected in both Parallel" and "Unit" modes. *
6. Establish admin_istrative cpntrols to ensure that changes to the plant design basis that occur through analysis are property controlled and evaluated for potential verification testing.
  • NRC_ Form 366A U.S. NUCLEAR REGULATORY COMMISSION IB-831 APPROVED OMB NO. 3160-0104 EXPIRES: 8/31/86

. LICENSEE EVENT REPORT (LERI TEXT CONTINUATION FACILITY NAl\ll E 11 l DOCKET NUMBER 121 LER NUMBER 131 PAGE 141 SEQUENTIAL REVISION YEAR NUMBER NUMBER Palisades Plant 0500025594 -o 7 - 0 0 0

  • 8 OF 0 8
7. Evaluate the design margin that exists for both EDGs with respect to the maximum accident required loads and d~termine the possible alternatives that exist to increase t~e margin.

Additional Information A supple~ent to this LER will be provided when the formal evaluation of the past operability of the ED Gs .1s completed. * * * *. ..

FIGURE l EMERGENCY DIESEL GENERATORS KILOWATT TABLE PARAMETER DIG 1-1 DIG 1 ~2 TWO HOUR ACCIDENT RATING 2750 KW 2750 KW

- 2500 KW .*

CONTINUOUS RATING 2500 KW . ,

TECHNICAL SPECIFICATIONS 2300 TO 2500 KW * '*"2300 TO 2500 KW.

MONTHLY LOAD TEST RANGE ..,

MAXIMUM ANALYZED POST.OBA PRESENT* - 2688 KW ..-' PRESENT - 2663 KW ACCIDENT LOADING PROPOSED - 2584 KW . PROPOSED* - 2559 KW

  • MAXIMUM LOAD CARRYING AS FOUND - 2438 KW AS FOUND - 2651 KW CAPABILITY-SEPTEMBER 1994 (ref~rence no_tes 1 and 2) * ~S LE.FT - 2714 KW AS LEFT - 2697 -KW .
  • ORIGINAL VENDOR PEAK , 28.10 KW " 2827 KW "

lOAD TESTING- 1969 NOTES:

1. The as-found and. as-left data includes an instrument ina*ccura~y penalty of 0.5 % of the re~ding. *
2. The as-left. recorded value for the EOG 1-2 is the best e~timate of steady state*

engine output. The peak load test was performed during a period wh*en the electrical grid was unsteady. It appears that EOG 1-2 has additional load carrying capabilities beyond the value of 2697 KW and future peak load tests will determine its full capabilities. * *

    • .j, . *.

EDG Historica I Load in gs 2~,....---------*~(M_a_x_._D. . .B_A_A_n_a_..;._ly_z

... e_dr--L_o_a_d..;__}--'-----r-~-,..,.,~~,

2 4 2~8 KW 2qp3

. t*.: .

. ~oo-L-~~~~+--~--~~+---~~~~+--~-r-~----ir--~-.-~--4 81 82 ..* 83 *., 84 . 86. . 87 .* . . 88 90 93. 94

  • Legend .

e edg 1-1 . X edg 1-2 YEAR

\..*

. i I .

EDG -1~,.1 STEADY STATE LOADING.

- KILOWATIS VS- TIME.

2900.------------------------------------------------------

EOG TWO HOUR RATING (2750 KW) 2611 KW C AUIOmaticllly SClquaac:cd Lam Plua M...W Load JA~~u.a---_-~

W4KW I 2400 2IOO

~._ ____________________________________......______ ______. ...._

0 40 60 .. IO , . '100 120 140 TIME MINUTES

EOG 1-1 STEADY STATE LOADl*NG Willi PROPOSED EOP CHANGES 2900.-------------------------------------------------------.

2800 -

EOO nvo HOUR RATING (2750 KW) ltlOO -

~ ~:::::::::-.__r 2'14KW .. A-...;..oy ......... Lool"'*"-'7.*.

~ '- l474KW'. .

.2400 - ""

2l00 -

DID -

2100 .....

I I I I I I 2mO a .20 40 . 60 IO. 100 120 140

.TIME MINUTES

~ .

!'I EOG 1-2STEADY.STATELOADING KILOWATIS VS TIME 2900-------------------------------------------------------

2IOO

. EDG nvo HOUR RATINO (%750 KW).

2600' 2500

~

¥: .....

2<<IO . Ci) c:

a 2300 ""

U1 f **

2200

:~ - :

2UIO

. DID._.____.....______ .______......,_______..._______,_______....___.____.

. 0 60 IO 100 120 140 TIME

  • MINUTES

"\

EOG 1-2 STEADY STATE LOADING WI11I PROPOSED EOP CHANGES 2900 2800 I-EOO 1WO HOUR RATING (7750 KW)

I- I

._  :.e

--*~-~PWMm~?

ll59 KW~

I

~ . ..,,....

2400

- 2G7KW"\ Ci) .

c::

a

. 2300 I-

'\ . .* 0\

I-

-~**~7.

2100

.. 0 I

20 I

40 ..

I 60 TIME i

80 I

100 I

l:ZO . 140 MINUTES

. !

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