ML20215J815
| ML20215J815 | |
| Person / Time | |
|---|---|
| Site: | Mcguire |
| Issue date: | 09/09/1986 |
| From: | Tucker H DUKE POWER CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8610270199 | |
| Download: ML20215J815 (14) | |
Text
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e DUKE POWER GOMPANY P.O. ISOX 33180 I
CIIAHLOTTE, N.C. 28242
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September 9,1986 Dr. J. Nelson Grace, Regional Administrator U.S. Nuclear Regulatory Connission Region II 101 Marietta St. NW, Suite 2900 Atlanta, Georgia 30323
Subject:
McGuire Nuclear Station, Unit 2 Docket No. 50-370 Technical Specification 4.8.1.1.3/6.9.2 Diesel Generator Failure Special Report
Dear Dr. Grace:
Pursuant to Technical Specifications 4.8.1.1.3 and 6.9.2, please find attached a Special Report reporting a valid Diesel Generator (D/G) failure which occurred on D/G 2B during a routine operability test on July 25, 1986 due to a failed turbo charger. This report is included in Attachment 1.
As this failure was the seventh valid failure in the last 100 valid tests on the Unit 2 D/G's, Attachment 2 contains a report documenting the operability of the D/G's pursuant to Regula-tory Guide 1.108 and Technical Specification 4.8.1.1.3.
The diesels are operable and the incident is considered to be of no significance with respect to the health and safety of the public. This report is not submitted within thirty days in accordance with my letter of August 25, 1986.
Very truly yours,
'/
lh Hal B. Tucker JBD/69/jgm Attachment xc:
INP0 Records Center Mr. W.T. Orders Suite 1500 NRC Resident Inspector 1100 Circle 75 Parkway McGuire Nuclear Station Atlanta, GA 30339 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C.
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3 ATTACHMENT 1 DUKE POWER COMPANY i
McGUIRE NUCLEAR STATION i
DIESEL GENERATOR 2B VALID FAILURE DUE TO TURBOCHARGER FAILURE INTRODUCTION: On July 25, 1986, at approximately 1040, during an operability test on Diesel Generator (D/G) 2B, the D/G made a loud noise and the load dropped from i
4000 kilowatts (KW) to 1000 KW.
The Nuclear Equipment Operator (NEO), who was in
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the D/G room at the time of the incident, completed the shutdown of the D/G. An emergency work request was written and D/G 2B was declared inoperable and start attempt number 478 was logged as a valid failure. Start attempt 478 was the seventh valid failure :b2 the last 100 valid tests on Unit 2 D/Gs. The special report due as the result of the seventh valid failure within the last 100 valid tests (as required by Technical Specification (T.S.) 4.8.1.1.3'and Regulatory l
Guide 1.108) is included as Attachment 2.
D/G 2B and the associated generator and breaker were inspected; no problems were found.
At 2143, D/G 2B was started for troubleshooting. The D/G started but did not reach 95% speed within 11 seconds as required by T.S. 4.8.1.1.2.
D/G 2B was j
loaded to 1000 KW.
The turbocharger was making excessive noise. D/G 2B was shut down and personnel started inspecting the turbocharger.
It was discovered that the compressor of the turbocharger was badly damaged and preparations were started to remove the damaged turbocharger. The replacement of the turbocharger was l
completed on July 28, at 0500.
r Unit 2 was in Mode 1, Power Operation, at 100% power at the time of the incident.
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EVALUATION:
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Background
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Each unit at McGuire Nuclear Station has two independent diesel generators manu-j factured by the Norberg Manufacturing Company. These D/Gs ar? used to provide standby alternating current (AC) power to the equipment required to safely shut l
down the reactor in the event of a loss of normal power. The D/Gs also supply power to the safeguards equipment as required during a major accident coincident l
with a loss of normal power (blackout).
l Each D/G at McGuire has associated with it a turbocharger. The turbochargers are manufactured by Brown Boveri (model number VTR 500) and consist of turbine blades i
and compressor blades mounted on a single shaft. The maximum speed of the turbo-l charger is 15,000 revolutions per minute (RPM).
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Air input to the turbocharger is taken from the atmosphere through an intake j
filter. The turbocharger compresses the air and forces it through an intercooler, which removes the heat of compression. From the intercooler, air passes to the inlet manifold and to the cylinder for combustion.
Exhaust gases discharge from j
the cylinders into the exhaust manifold and to the turbine compartment of the a
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The turbocharger is independently lubricated by an integral oil feed system. The oil level and supply to the turbocharger bearings say be determined at either end of the turbocharger by observation through the sight glasses in the bearing covers. Cooling water is provided from the engine cooling system.
I When the air pressure in the engine air manifold exceeds the pressure that the j
turbocharger compressor can sustain, air flows from the maifold back d. rough the compressor. When this occurs, the turbocharger is said to be surging. The reverse flow of air causes a repeated muffled to sharp explosive type of noise, of ten referred to as " barking" of the turbocharger.
Sometimes when surging takes place, the noise is so muffled that it becomes difficult to distinguish over the normal engine noise.
The turbochargers at McGuire are built to handle a small amount of surging; however, continued operation with the turbocharger surging can result in damage to the turbocharger, bearings, or the compressor.
Description of Event On July 25,1986, at 0930, D/G 2B was started (start attempt number 478) to perform an operability test. At approximately 1040, while standing at the D/G local control panel taking data, a NEO heard a loud noise. When the NEO turned to look at the engine, he saw a puff of smoke from the top of the engine being drawn into the ventilation system. When the NEO turned back around to the control panel, he noticed that load had dropped from 4000 KW to 1000 KW.
The NEO shut down D/G 28.
During the coast down of the D/G, the NEO did not notice any unusual noise in the D/G or turbocharger. The NEO informed other personnel of the inci-dent who wrote an emergency work request to investigate and repair D/G 2B.
D/G 2B was declared inoperable and start attempt number 478 was logged as a valid fail-ure. At approximately 1300, personnel began inspecting D/G 2B.
The D/G was placed on turning gear, all cylinder test ports were opened and pressure in all 16 cylinders was verified. Personnel also removed all crankcase doors on the right 4
side of the D/G to check the rod bearings and main bearings. No damage was found.
All valve covers were removed to inspect the cylinder heads. No damage was found.
The electrical generator of the D/G was inspected and no problems were discovered.
D/G 2B was returned to operating condition in preparation to start the D/G for troubleshooting.
At 2143, start attempt number 479 was performed on D/G 2B for maintenance troub-leshooting. The D/G did not reach 95% speed within 11 seconds as required by T.S.
4.8.1.1.2.
(The actual starting time was 11.88 seconds.) The D/G was loaded to 1000 KW.
The turbocharger was noisy and vibrating. The D/G was shut down and start attempt number 479 was logged as an invalid test failure.
t The oil was drained from the turbocharger, the cover plate was removed and the bearings and turbine blades were inspected. Personnel found metal shavings and believed the shavings were from the bearings. The expansion joint was removed from the compressor side of the turbocharger to inspect the compressor side bearings. When the expansion joint was removed, it was discovered that the coupressor blades were badly damaged.
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Page 3 From approximately 0400, on July 26, 1986, until 0500, on July 28, personnel replaced the turbocharger on D/G 2B and performed an associated inspection and clean-up. Some of the work performed was as follows:
- 1) remove, inspect, and pressure test the intercooler, 2) remove all fuel injectors, inspect the cylinders using a boroscope, and vacuum each cylinder, 3) vacuum inlet and exhaust piping of the turbocharger, 4) obtain a new turbocharger from the warehouse, disassemble, inspect and clean parts and 5) install new turbocharger.
On July 28, at 0507, start attempt number 480 was performed on D/G 2B for troub-leshooting. The D/G was loaded to 4400 KW while vibration readings were taken on the turbocharger. No problems were discovered. The D/G was shut down and start attempt number 480 was logged as an invalid test. The oil in the turbocharger was changed on the recommendation of the turbocharger manufacturer representative. At 0625, D/G 2B was started (start attempt number 481) for an operability test. At 0740, D/G 2B was shut down after successfully completing the operability test.
D/G 2B was declared operable at 0920.
Conclusion D/G 2B was inoperable from July 25, at 1045, to July 28, at 0920, a total of approximately 70.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. The valid failure during start attempt number 478 was the seventh valid failure in the 1Fst 100 valid starts on Unit 2 D/Gs. The test frequency of the Unit 2 D/Gs was not increased but a report on the reliability of the Unit 2 D/Cs is required and is included as Attachment 2.
During the time D/G 2B was inoperable, D/G 2A was started 10 times to verify starting capability. An operability test was also performed on D/G 2A on start attempt number 434. During the operability test, Duke personnel, along with the turbocharger manufacturer representative, listened for abnormal noises in the i
I turbocharger during startup, loading, operation, and shutdown. No abnormalities associated with the turbocharger were noted.
On August 1, 1986, at 0745, D/G 2A was declared inoperable to allow personnel to visually inspect the turbocharger.
It was discovered that the stationary diffuser blades of the turbocharger were " curled" or bent. The deformaties were first thought to be the result of over-heating but no analysis has been performed. The turbocharger on D/G 2A was replaced and D/G 2A was declared operable on August 2, at 2020, after successfully completing an operability test, Quality Assurance personnel performed a dye pentrant test on the diffuser blades and the compressor blades of the turbocharger that was removed from D/G 2A, The test indicated several cracks on the diffuser blades but none on the compressor blades.
On August 5, 1986, at 1530, D/G 1B was declared inoperable to allow an inspection of the turbocharger. The inspection, which included a dye penetrant test on the diffuser section and rotor section, showed no abnormalities. D/G 1B was declared operable on August 11, at 0130, after successfully completing an operability test.
The turbocharger on D/G 1A was not inspected. The turbocharger was replaced in March of 1984, when an intake valve broke and went into the turbocharger causing damage.
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Page 4 On July 27, 1986, an independent consultant who is a former executive with Nord-berg Manufacturing Company was contacted. The consultant was asked how serious the turbocharger failure was from an engine standpoint and had any possible damage been done to the engine. He made several recommendations:
Run a cylinder compression test on all cylinders to see if any debris had lodged under the valves, causing leakage; Clean the compressor discharge piping and air manifolds to the intercooler; Examine the broken wheel for defects, corrosion and other damage.
All of these have been done. The consultant was contacted again and informed that a Duke Power metallurgist had determined at least two of the compressor turbo-charger blades failed due to istigue.
The consultant was asked if surging could have contributed to the fatigue of the compressor blades. The consultant stated that surging does effect the life of the compressor blades and listed several items about surging. Operating the engine at a higher load than designed, an inefficient intercooler and sudden losses in load (as in tripping from full load) all contribute to surging. However,'it has not been determined if surging con-tributed to the fatigue of the compressor blades.
A review of past incident reports indicates there have been no incidents involving damaged turbochargers caused by the turbocharger failing. Although the turbo-charger on D/G 2A was replaced due to damaged diffuser blades, it was not consi-dered a failure of the turbocharger; therefore, this incident is not considered recurring.
The failure of the turbocharger on D/G 2B rendered the D/G inoperable. The exact cause of the failure of the turbocharger is unknown, but indications of fatigue were found on two of the turbocharger compressor blades. The cause of the fatigue is still under investigation.
SAFETY ANALYSIS: Technical Specification 3/4.8.1 requires that when either an offsite AC electrical power source or D/G is inoperable, the operability of the remaining power sources be demonstrated within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 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. Ten operability runs were performed on D/G 2A (while D/G 2B was inoperable) starting at 1125, on July 25.
The operability of the AC and direct current (DC) power sources and associated distribution systems during plant operation ensures that there is sufficient power available to supply the safety-related equipment required for:
(1) the safe shutdown of the facility, and (2) the mitigation and control of accider.t condi-tions within the facility. Also, the definition of operability does not make reference to emergency power. This allows the train without emergency power (i.e., D/G not available) to be considered operable if it has normal power and the redundant train has emergency power and is operable.
Page 5 When one D/G is inoperable, there are requirements to verify that all required systems, subsystems, trains, components, and devices that depend on the remaining operable D/G as a source of emergency power be operable. This provides assurance that a loss-of-offsite power event will not result in a complete less of safety function of critical systems during the period that one of the D/Gs is inoperable.
All of these requirements were met.
D/G 2A was operable and available during the period in which D/G 2B was inoper-able.
The health and safety of the public were not affected by this incident.
. _ _ _ _ _ _ _ _. _. _... _. _. ~
ATTACHMENT 2 SPECIAL REG GUIDE 1.108 REPORT GalaEal The following information is provided in response to the requirements of USNIIC Regulatory Guide 1.108 revision 1, section C.3.b.
This regulatory guide section requires that additional narrative material be supplied if the nunber of failures in the last 100 valid tests is seven or nore. On July 25, 1986 a valid failure occurred on McGuire engine 28. This was the seventh valid failure in the last one hundred valid tests for the two Md3uire Unit 2 emergency diesel generator sets.
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-.t. --u ran The following are descriptions and basis for corrective measures, taken or planned, to increase t.he reliability of the generator units.
Replace all engine exhaust manifold expansion joints enca every a.
five refueling outages, starting from the date they were last changed.
It was found that the expansion joints become brittle after about 4000 to 5000 hrs of exposure to hot exhaust gasses. In scic cases the joints have broken and partially closed off the exhaust manifold by obstructing the pre-turbocharger screen.
The five refueling outage period is meant to approximate five It is estimated that the engine will have run only 1500 years.
hours during this period. This practice will be continued until a workable alternative is found such as the introduction of an inproved material.
Test, inspect and calibrate all electrical couponents associated b.
with the engine over speed protective systems, (such as speed switches, relays, proximity switches, wiring, etc) on each engine every other outage. These tests may be staggered so that only one engine is done per outage.
This item stems from the investigation of the May 12, 1986 valid failure on engine 2A in which a nunber of connections were found loose and a speed switch needed calibrating. Systens of this type are subject to increased problems as they age because of If, the long term effects of heat, vibration, and oxidation.
however, after the third insp=+ ion of each engine no degrada-tion is noted, the testing may be postponed until the tenth refueling outage from the date of the last inspection. The span of a refueling outage is meant to approximate one year.
The turbocharger rotor assenbly will be replaced once every five c.
refueling outages starting with the last replacement. Also dye penetrant inspect all diffuser blades and repair or replace than If two replacements occur in the same outage, the as necessary.
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replacement and inspection of the least operated of the two may be deferred until the sixth outage.
Se investigation into the cause of the fatigue failure of the turh~ harger compressor inge11er blades is continuing. Having been constructed of aluminum, the inpeller blades have a finite life. While Brown heri (BBC) turbochargers are known for their reliability, it is not fully known what effect that frequent fast starts and the uprating of the engine by 500kw has had on them. Se span of a refueling outage is meant to approx-imate one year. Replacing the rotor assembly at a mad== of six outages should limit the engine to about 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> and 2000 starts. This is well within the 5600 hours0.0648 days <br />1.556 hours <br />0.00926 weeks <br />0.00213 months <br /> the 2B turh~4=rge had at failure and the 8000 hour0.0926 days <br />2.222 hours <br />0.0132 weeks <br />0.00304 months <br /> bearing limit rar==anded by;(
i BBC. The practice of replacing the rotors periodically will continue until more data is obtained on compressor inpeller life.
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7brbocharger oil will be periodically sampled and spectrographically analyzed quarterly for contaminants and wear particles.
This test has been added to the oil sampling portion of the preventative maintenance program already in progress at the j
station. Sanpling was begun as a result of the failure of the engine 2B turbocharger.
Perform the following lube oil system inprovements:
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Modify the lube oil filter systen to handle 100% of engine flow.
2.
Filter all new lube oil that is added to the engine to 5 microns.
3.
Switch to an oil with a total base nunber of 12 or more and an anti-wear additive such as zinc-dithiophosphate.
2ese ra<w==ndations are meant to mitigate the effects of and reduce the chance of bearing and crankshaft damage from oil abrasives and wear particles. S e failure of the engine 2A bearings requiring the replacement of the crankshaft is an exanple of this. Se majority of diesels used in emergency i
service filter 100% of their lube oil as do the Catawba and j
S e filtering of new lube oil to 5 microns has Oconee engines.
been done since a bulk shipnent of oil from one supplier was found to contain sand. In switching to a new oil, the anti-wear additive sticks to the parts to provide lubrication during the first few rotations of a start.
4 Couplete failure analysis of all failed diesel engine parts will f.
be performed and appropriate action will be taken based on these results.
A change to the Technical Specifications was submitted July 10, g.
1985 and supplemented April 15, 1986. It included a proposal which would reduce the frequency of fast starts.
Enaine Em14ahility Aanmanment of the 100 valid tests covered by this report, engine 2A suffered 5 failures in 52 tests and engine 2B suffered 2 failures in 48 tests.
'No different approaches can be used to evaluate the reliability.
One approach treats each diesel as having a separate failure rate.
'Ibe failure rate for each engine is calculated arul the two rates are then conbined to give a reliability for the system. Using this approach engine 2A has a failure rate of between 0.0635 to 0.1400 with a 50% confidence factor with a mean of 0.0943 or 90.57% reli-ability. Ehgine 2B has a failure rate of between 0.0204 to 0.0834 with a 50% confidence factor with a mean of 0.0425 or 95.75% reli-ability. 'Ibe reliability of the system, or of at least having one of the two engines operate successfully is the product of the two failure rates subtracted from unity. This results in a reliability rate of between 0.98832 and 0.99870 with a 50% confidence level and a mean of 0.99599 or 99.6% reliable.
The second method treats both engines as having an average failure rate of 7 out of a hundred tests or each is 93% reliable. 'Ihe reliability using this method is between 0.99063 and 0.99742 with a 50% confidence level and a mean of 0.99510 or 99.5% reliable.
Both methods yield values that exceed the 0.99 reliability goal at a 50% confidence level established by NURBG75/087 appendix 7-A.
Ranin for Continnad charation The plant will continue to be operated because the reliability of i
electric power to the engineered safety feature equignent exceeds the goal required by regulations and stringent programs are in place to inprove engine reliability beyond this goal.
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'Ihe McGuire Technical Specifications currently require that the diesel engine operability test (Pr/2/A/4350/02) be performed once every 31 days if one valid failure (W) or less has occurred in the last 100 valid attempts, every 14 days for 2 W's, every 7 days for 3 W's, and every 3 days for 4 or more W's.
Attached is a sunnary of the start attenpts for engines 2A and 2B.
" Valid Attempt Nunber" is a counting of the most recent 100 valid successes (VS) or valid failures (W) for the Unit 2 engines ccm-bined.
" Engine Start Nunber(s)" are assigned to each engine start and are recorded together with other information about each run, in the
control room log books. '1he nunbers began when the engines were first declared operable at McGuire.
" Test Result" is one of four possible codes, VS, VF, IT, or IF. VS stands for valid success. If during one of the periodic test runs required by the Tech. Specs., the engine attains 95% of full voltage and speed in less than eleven seconds and runs for at least 60 minutes at 4000kw load, a VS is recorded. If during this test the engine fails to meet these standards, a VF for valid failure is recorded. IT, for invalid test, is recorded for a start when there is no intention to test the engine at load for an hour, such as for trouble shooting, but the engine does scart successfully. An IF, for invalid failure, is recorded when the engine does not start for an invalid test.
Engine 2A had 48 VS's, 5 VF's, 69 IT's, and 3 IF's and engine 2B had 45 VS's, 2 VF's, 37 IT's, and 1 IF during the period that included the last 100 valid tests.
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Valid Engine 2A Engine 2B Attempt Start Test Test Start Test Test Number Number Result Date Number Result Date 1
302 W
MW 295 VS 12/26/85 3
303 VS WM 296 VS 1/9/86 304 IT 1/14/86 297 IT 1/17/86 298 IT 1/17/86 5
305 VP 1/17/86 306 IT 1/17/86 299 IT 1/18/86 300 IT 1/18/86 6
307 VS 1/18/86 308 IT 1/22/86 309 IT 1/22/86 310 IT 1/22 M 301 VS 1/23/86 7
311 IT 1/23/86 8
312 VS 1/24/86 302 IT 1/29/86 313 IT 1/2 W 303 IT 1/30/86 314 IT 1/30/86 304 VS 1/30/86 9
305 IT 1/30/86 10 315 VS 1/31/86 316 IT 2/4/86 317 IT 2/4/86 318 IT 2/5/86 319 IT 2/5/86 306 VF 2/6/86 320 IT 2/6/86 12 321 VS 2/6/86 307 IT 2/7/86 322 IT 2/7/86 308 VS 2/9/86 14 323 VS 2/10/86 309 IT 2/10/86 310 VS 2MM 15 324 IF 2/13/86 311 IT 2/13/86 6
325 VS 2/13/86 312 VS 2/15/86 18 326 VS 2/16/86 313 VS 2/18/86 314 VS 2/20/86 21 327 VS 2/21/86 315 IT 2/22/86 316 IT 2/22/86 317 IT 2/22/86 318 IT 2/23/86
Valid Engine 2A Engine 2B Attempt Start Test Test Start Test Test.
Number Number Result Date Number Result Date 328 IT 2/27/86 319 VS 2/27/86 22 329 IT 2/27/86 23 330 VS 2/28/86 24 320 VS 3/6/86 25 331 VS 3/7/86 26 332 VS 3/14/86 321 VS 3/14/86 27 333 IT 3/16/86 28 334 VS 3/16/86 322 IT 3/17/86 323 IT 3/18/86 324 IT 3/18/86 325 IT 3/18/86 326 VS 3/20/86 29 327 IT 3/21/86 328 IT 3/22/86 329 VS 3/27/86 30 335 IF 4/1/86 31 336 VF 4/1/86 330 VS 4/2/86 32 331 VS 4/10/86 33 332 VS 4/13/86 34 333 VS 4/16/86 35 337 IT 4/17/86 338 IT 4/17/86 339 IT 4/17/86 340 IT 4/17/86 341 IT 4/17/86 342 IT 4/17/86 334 VS 4/19/86 36 343 IT 4/20/86 344 IT 4/20/86 37 345 VS 4/20/86 38 346 VS 4/21/86 39 347 VS 4/24/86 348 IT 4/27/86 40 349 VS 4/27/86 41 350 VS 4/30/86 42 351 VS 5/3/G6 43 352 VS 5/6/86 335 IT 5/7/86 336 IT 5/7/86 337 IT 5/7/86 338 IT 5/7/86 339 IT 5/8/86 340 IT 5/8/86 341 IT 5/8/86 342 IT 5/8/86 343 VS 5/8/86 44
s Valid Engine 2A Engine 2B Attempt Start Test Test Start Test Test Number Number Result Date Number Result Date 45 353 VS 5/9/86 344 VS 5/11/86 46 47 354 VF 5/12/86 355 IT 5/12/86 48 356 VS 5/12/86 345 IT 5/13/86 357 IT 5/13/86 346 VS 5/14/86 49 50 358 VF 5/15/86 359 IT 5/15/86 360 IT 5/15/86 361 IT 5/15/86 362 IT 5/15/86 363 IT 5/15/86 365 IT 5/16/86 366 IT 5/16/86 367 IT 5/16/86 347 VS 5/17/86 51 52 368 VS 5/19/86 348 VS 5/20/86 53 349 IT 5/21/86 350 IT 5/21/86 351 IT 5/21/86 352 IT 5/21/86 369 IT 5/22/86 l
54 370 VS 5/22/86 353 VS 5/23/86 55 l
56 371 VS 5/25/86 354 VS 5/26/86 l
57 58 372 VS 5/28/86 355 VS 5/29/86 59 373 IT 5/30/86 60 374 VF 5/31/86 356 VS 6/1/86 61 375 IT 6/1/86 376 IT 6/1/86 377 IT 6/1/86 378 IT 6/3/86 379 IT 6/3/86 62 380 VS 6/3/86 381 IT 6/3/86 382 IT 6/3/86 383 IT 6/3/86 384 IT 6/3/86 385 IT 6/3/86 357 VS 6/4/86 63 386 IT 6/4/86 387 IT 6/4/86 388 IT 6/4/86 389 IT 6/5/86
i Valid Engine 2A Engine 2B Attempt Start Test Test Start Test Test Number Number Result Date Number Result Date 390 IT 6/5/86 391 IT 6/5/86 64 392 VS 6/6/86 393 IT 6/6/86 394 IT 6/6/86 65 395 VS 6/6/86 396 IT 6/6/86 397 IT 6/6/86 66 358 VS 6/7/86 398 IT 6/7/86 399 IT 6/9/86 400 IT 6/9/86 67 401 vs 6/9/86 402 IT 6/9/86 403 IT 6/9/86 404 IT 6/9/86 68 405 VS 6/10/86 406 IT 6/10/86 69 407 VS 6/10/86 359 VS 6/10/86 70 360 IT 6/11/86 4
71 408 VS 6/12/86 361 VS 6/13/86 72 409 IT 6/13/86 73 410 VS 6/16/86 362 VS 6/16/86 74 75 411 VS 6/18/86 363 VS 6/19/86 76 77 412 VS 6/21/86 364 VS 6/22/86 78 79 413 VS 6/24/86 365 VS 6/25/86 80 81 414 VS 6/27/86 366 VS 6/28/86 82 83 415 VS 6/30/86 367 VS 7/1/86 84 85 416 VS 7/3/86 368 VS 7/4/86 86 87 417 VS 7/6/R6 369 VS 7/7/86 88 418 IF 7/9/86 370 IT 7/9/86 371 IT 7/9/86 372 IT 7/9/86 89 419 VS 7/9/86 373 VS 7/10/86 90 420 IT 7/10/86 91 421 VS 7/12/86 374 VS 7/13/86 92 93 422 vs 7/15/86
s Valid Engine 2A Engine 2B Attempt Start Test Test Start Test Test Number Number Result Date Number Result Date 1
375 VS 7/16/86 94 423 IT 7/16/86 424 IT 7/16/86 95 425 VS 7/18/86 96 376 VS 7/19/86 97 426 VS 7/22/86 98 377 VS 7/22/86 99 427 VS 7/24/86 100 378 VF 7/25/86 379 IF 7/25/86 i
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