ML20198C395
| ML20198C395 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 11/05/1985 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20198C389 | List: |
| References | |
| NUDOCS 8511120081 | |
| Download: ML20198C395 (16) | |
Text
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Enclosure 1 NRR STAFF PRESENTATION TO THE ACRS SUBJECT *. STATUS OF NRC TASK FORCE EVALUATION OF TDI DIESEL GENERATOR RELIABILITY DATE: MARCH 20.1985 PRESENTER: CARL H. BERLINGER PRESENTER'S TITLE / BRANCH /DIV: BRANCH CHIEF TDI PROJECT GROUP DIVISION OF LICENSING PRESENTER'S NRC TEL. NO.: 492-9794 l
SUBCOMMITTEE: ELECTRICAL SYSTEMS SUBCOMMITTEE
$0k21$00!k OSoohjo E
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l Summary of Conclusions and Recommendations on ,
Resolution of Known Problems in ,
TDI Diesel Generator Components
{ Phase I of Owners' Group Program) [
Pacific Northwest Laboratory ,
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Part,icipants in Reviews
! -l
- ., u c.
- . w-Consultants
! e S.H. Bush '
e A.J. Henriksen l e B.J. Kirkwood i
i e P.J. Louzecky l
l e Ridardo Consulting Engineers plc, West Sussex, j England i
- e A. Sarsten PNL Technical Coordinators e F.R. Zdloudek, Task Leader -
j e J.M. Alzheimer 1
e J.F. Nesbitt -
? -
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Information Considered by PNL in Reviews of Resolution of Known Probisms -
G o Owners' Group reports on known problems e Operating experience in nuclear and non-nuclear applications e Plant-specific reviews
.- Grand Gulf i: July;>
- Catawba I August;l Comanche Peak i: September;i i
- San Onofre i: November;l - .
- Shoreham (December;l
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Air Start Valve Capscrew Type Failures:
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- 1) Loosened capscrew at Shoreham and l Grand Gulf due to bottoming-out during torquing '
- 2) No failures have occurred .
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i i Air Start Val 6e Capscrew j
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Conclusions:
l: Capscrew design is adequate, provided that
- sampling procedure.is. established to ensure capscrews are of sp4cified length l - installation is made according to SWEC recommendations
! M/S Recommendations:
Capscrews should be torqued to Owners' Group l recommendations and retorqued following first period of engine operation whenever an air-start l
i valve is removed / replaced i
l Auxiliary Module Wiring and J Terminations 1
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Concern:
Suitability of all class IE auxiliary module wiring and terminations -
j - Flame retardancy l - Qualification to industry standards . .
! - Routing in conduit i
- Compatibility with circuit requirements
Conclusions:
PNL concurs with OG that wiring and terminations are adequate with indicated modifications
! - Shoreham l - Replace crankcase ventilating fan wiring '
- Inspect sliding link terminal block
! - Catawba .
- Replace wiring of questionable integrity
- Inspect sliding link terminal blocks
- San Onofre '
- Replace wiring of questionable integrity i 4-
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Connecting Rods -
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(DSR-48 Engines)
Conclusions:
PNL concurs with OG that
- Rods adequate for intended service i
- Indications in rod eye bushing within 15 of
- bottom center are not acceptable
- Rod eye cracks more than 0.04 inch deep are not l
acceptable i - No detectable cracks allowed at root of rod bolt threads l
Recommendation: '
l
. - - - - - _ . - . . . . . ... ....---..---.- + - . . = = + -
j Connecting rod bolts should be torqued to OG/TDI i
recommendations at each major engine disassembly (approx. every 5 years) -
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a l Connecting Rods l
(DSRV-4 Engines) .
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l Type Failures:
1.;l None in nuclear service i
2;i Fatigue cracking of connecting rod -
bolts, link rod box, and fretting of ,
i serrations (non-nuclear service;>
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Connecting Rods _ _
[DSRV-4 Engines) H
Conclusions:
l 1D Analytical evidence alone does not provide a
- sufficient basis for concluding that connecting rods '
j are adequate l
l 23 Service history provides confidence that, with suitable M/S, continued use is justified i Recommendations:
f
! 1? Implement OG recommendations l - Inspect and measure every 5 years l - Measure clearance between link pin and link rod 1
every 5 years
- Visually inspect rack teeth; verify minimum specified contact surface i - Inspect 17/8-inch bolts and bolt holes each -
4 270 hours0.00313 days <br />0.075 hours <br />4.464286e-4 weeks <br />1.02735e-4 months <br /> above 50% load 2? Bolt torque (both 1 1/2 and 17/8-inch bolt sizes) should be checked every 270 hours0.00313 days <br />0.075 hours <br />4.464286e-4 weeks <br />1.02735e-4 months <br /> of operation above 50% load or every 5 years
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1 l Connecting Rod Bearing Shells
[ Type Failures:
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! 1? Cracked bearing shells at Shoreham after only 600-800 hours of operation 2? No other reported failures in nuclear i service i
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Connecting Rod Bearing Shells -
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Conclusion:
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Bearing shells are suitable for continued use with 4
enhanced M/S l M/S Recommendations of Owners' Group:
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l - Inspect and measure every 5 years i
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- Bump test at each refueling cycle
- X-ray new bearing shells per OG criteria h
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- Crankshaft
! (R-48, Shoreham) i l Type Failures: .
i 1;l Fracture of Shoreham EDG 102 11-inch crankshaft ,
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l . 2;l Cracks in EDG 101 and 103 .
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Crankshaft
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(R-48, Shoreham? .
i l Conclusions regarding replacement 12-inch crankshafts:
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- 1;I Test to 10 7 stress cycles proves adequacy of l Shoreham crankshafts for " qualified" load l (3300 kW)
I 2;i Portion of test at higher loads provides basis for l concludi6g loads to 3430 kW are acceptable for
! limited period in emergency
! 3) Momentary ( <1 minute? loads to 3900 kW in emergency would not compromise operability M/S Recommendation:
l 1) NDT fillets and oil holes of crankpin journals 5,6, and 7 and main journals between them.in EDG 101 and 102 engines at first refueling outage l
- 2) NDT of fillets and oil holes of two most heavily
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Crankshaft '
I (DSRV-16-4, Grand Gulf)
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Conclusions:
- 1) Comply with DEMA recommendations for torsional stresses at
! rated speed .
l 2) System has 4th order critical at 432 rpsh (within i 5% DEMA
- range)
- Engine should not be operated below 440 rpm l - Cylinder load balance is important j - Misfirmg especially undesirable .
! M/S Recommendations:
i . . . . . . . . . . . . . . . . _ . . . . . - . . . _ . . . . . _ . .
- 1) Measure hot and cold deflections at 270 hours0.00313 days <br />0.075 hours <br />4.464286e-4 weeks <br />1.02735e-4 months <br /> or each refueling (OG)
! 2) Inspect journals 4, 6, 8 (OG) i
! 3) Determine adequacy of TDI cylinder balance /governer speed l variations by torsiograph (OG) l l 4) Following major maintenance, balance cylinders carefully per TDI .
) procedures (PNL) l 5) Monitor for misfiring via exhaust temperatures (PNL)
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Crankshaft
- 'DSRV-20-4, San Onofre?
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- Type Failures
- -
Linear crack discovered in both
! crankshafts.
- Torsional vibration during rapid startup l likely cause
! - Cracks removed by remachining oil ,
j holes i
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Crankshaft '
(DSRV-20-4, San Onofre) .
j
Conclusions:
! 1) At rated load and speed, torsional stresses within DEMA limits '
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! 2) Engines conservatively rated j - Vibratory stresses low at 450 rpm
- 3) Crankshafts are adequate for their intended function, provided l that:
I - requirement for rapid start testing is removed
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- M/S is~ implemented to detect future cracking l
M/S Recommendations: I l 1) Hot and cold deflection checks at 270 hours0.00313 days <br />0.075 hours <br />4.464286e-4 weeks <br />1.02735e-4 months <br /> or each refueling (OG) l 2) Inspection of oil hole regions of journals 9,10 and 11 at refuelings .
! (OG) l 3) Following major maintenance, balance cylinders carefully per TDI l l procedures (PNL)
- 4) Monitor for misfiring via exhaust temperatures (PNL)
c .
Cylinder Block Type Failures:
- 1) Camshaft gallery cracks (8-cylinder engine) 2? Circumferential cracks in cylinder liner counterbore 3? Cracks in ligament between liner
. counterbore and stud 4? Stud-to-stud cracks ,
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Conclusions:
l 1) Camshaft gallery cracks
- Hot tears
- Not expected to propagate
- 2) Circumferential cracks -
- Caused by liner proudness
- Not detrimental to engine performance .
j 3) Ligament cracks i
- Not detrimental to engine performance
- Increase probability of stud-to-stud cracks
- 4) Stud-to-stud cracks -
l - Potential threat to engine integrity
- Must be evaluated on case-by-case basis Recommendations:
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l T) Camshah~ cracks should be monitored ~~
- 2) Circumferential cracks need not be monitored j 3) Where ligament cracks exist, check for stud-to-stud cracks i 1
after each operation at >50% load i l 4) Blocks with' known stud-to-stud cracks should be analyzed for l suitability for further service
.)
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Cylinder Heads -
i j Type Failures:
Crack originating at stellite valve seal i
allowing entrance of water into cylinder i
Failures have involved principally " Group I" heads (of the three groups in service) i J
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j Cylinder Heads -
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Conclusions:
Heads from all three groups are suitable for intended service, provided that: .
- firedeck has no plug welds '
- engine is rolled over 4 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after shutdown, again at 24
! hours, to detect water leaks. Engine is rolled again before l
planned starts j Recommendations:
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- Liquid penetrant inspection of fireheck l
- Record cold compression and maximum firing pressures at i each refueling
! - Roll over engine per PNL recommendations after 1
, shutdowns
- Visually inspect fuel injection ports during surveillance tests i
- Return leaking heads to vendor for repair i
! 2) Inspections prior to nuclear service
- Ultrasonic inspection of firedeck to verify thickness is at l least 0.400 inch 1
- Surface inspection of firedeck and valve seats to verify absence of unacceptable defects. Any heads with plug welds in firedeck should be rejected
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Cylinder Head Studs j
[ Straight and Necked Designs?
s Type Failure:
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- 1) None in nuclear service i
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- 2) Isolated failures in non-nuclear service '
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- from insufficient preload l
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Cylinder Head Studs l
i (Straight and Necked Designs) .
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Conclusion:
- PNL concurs with OG that both designs are suitable i for intended service l
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M/S Recommendation:
- - - - - ~ ~ - ' ~ -" "
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! Torque per Owners' Group /TDI recommendations l whenever a head is removed / replaced -
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- Engine Base and Bearing i Caps l Type Failures
i j 1) Cracks in main bearing saddles of DSR-l 48 engines (at Shoreham) from j improper stud removal l 2) Cracks in main bearing saddles from insufficient stud preload (marine service) j 3) Nut pocket failure due to defective j
F casting (non-nuclear) '
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i Engine Bdse and Bearing Caps 3
Conclusions:
l PNL concurs with OG that base and caps are adequate, provided that:
- LP examination of saddles is performed at alternate fuel cycles (DSR-48)
- main bearing saddle stud torque is checked at alternate cycles j - OG recommendations on removal of oil from l mating surfaces before assembly are implemented f
I Recommendation:
l Additionalinspection of cap and base mating surfaces l to ensure absence of imperfections preventing tight i
bolt-up -
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I Jacket Water Pump f
Type Failures:
Fatigue fai;ure of pump shaft initiating at keyway (Saudi Arabia and Shoreham) l o
O
- - , .m . _ _ _ _ _ _
L Jacket Water Pump l .
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Conclusions:
1ll Concur with latest Shoreham redesign and proposed
! River Bend and Rancho Seco redesign i
2ll Concur with OG that V-12, V-16 and V-20 designs are adequate with addition of torque values and limits to assembly procedures M/S Recommendations:
None -
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' Types AF and AE Piston Skirts l
i Type Failure: ,
I Fatigue cracks in skirt-to crown attachment bosses ,
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Types AF and AE Piston Skirts i
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Conclusions:
- 1;i Type AF skirts suitable
- Up to 130 BMEP with initial inspection only i - Over 130 BMEP l Initial inspection i 100% boss area inspection at each refueling i
2;i Type AE skirts suitable to normal TDI ratings M/S Recommendations:
l 1;l Inspection as above l 2;i inspection, measurement of pin and skirt per TDI
! recommendations .
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Types AN and AH Piston Skirts i
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! Type Failures:
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1? AN - Numerous reports of cracks in i
nuclear and non-nuclear applications
- 2) AH - No reports i
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Type AN and AH Piston Skirts
Conclusions:
i 1;l AN skirts not suitable i
2;i dH skirts suitable l - Normal TDI ratings I
- Subject to 10 7 cycle test on lead engine I M/S Recommendation:
l l Inspect skirt and pin every 5 years per TDI '
l recommendations 2
6 Push Rods (Ball .End, Forged-End and Friction-Welded Designs)
Type Failures:
Numerous failures of ball-end design in weld area e
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Push Rods -
l { Ball-End, Forged-End and Friction-I Welded Designs?
.i l Conclusionsi
! 1) Concur with OG that ball-end rods should be removed l l from service l 2) Concur with OG that forged-end design and friction-l welded design are acceptable I
M/S Recommendations: - --
- 1) Inspect after 800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> with LP; replace rods with detectable cracks
- 2) Implement OG recommendation for destructive
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examination of friction-welded design
- N+.. , , ,
- O Rocker Arm Capscrews
{ Original and Modified. Designs}
Type Failures:
Isolated fatigue failures from insufficient preload '
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- Rocker Arm Capscrew's i ' Original and Modifie'd Designs}
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Conclusions:
) 9-i 1? PNL pfedicts stress may be 3 times higher than SWEC j prediction, but margin remains adequate i
j 2? Both designs are adequate j
- based on conservative PNL stress estimate
- based on service history i M/S Recommendations:
1 1? Torque per Owners' Group /TDI recommendations .
whenever capscrews are removed / replaced
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! El.liott Model 65G/90G .
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Type-. Failure:
Thrust bearing failure from inadequate
! lubrication during startup l
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Elliott Ihlodel 65G/90G
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Conclusions:
! 1) Turbochargers are suitable, provided that
- FaAA recommendations on drip and full-l flow prelube systems are followed
- 2) Flange and piping alignment and surge margin are j possible plant-specific items ll l Recommendations:
! Follow OG recommendations on M/S
- Inspect bearings after 40 fast /100 total starts
- Measure . clearances, clean bearings, analyze oil at each refueling -
- Inspect bearings, other items each 5 years Consider operation of manual prelube system for brief period folfowing engine shutdown, to cool down bearings
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Inlet Nozzle Ring i Elliott Model 90G Turbocharger i
4 i Type Failures: ,,
l 1;l Vanes l Missing vanes
! Fatigue cracks in roots (Iow operating hours) l l 2) Broken bolts l
l 3) Cracked washers
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l 4) Cracked hub i.
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! ~ . . e _ _ . _ _
1 , =
- tr Inlet Nozzle Ring
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l Elliott Model 90G Turbocharger I
)
Conclusions:
i
) 1) No evidence that missing vanes had, in fact, been
! installed l 2) Fatigue cracks pose potential threat I
l Turbocharger destruction '
Performance degradation
! 3) Other isolated failures (e.g., bolts and washers? pose a .
less serious threat to operability l Recommendations: .
I l 1) Inspect at every refueling outage
- 2) Replace missing or cracked components -
)
ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS . -
t; .:
- 4. 8.1.1.1 Each of the above required independent circuits between the offsite transmission network and the onsite Class 1E distribution system shall be:
. a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignments and indicated power availability, and
- b. Demonstrated OPERABLE at least once per 18 months during shutdown by transferring unit power supply from the normal, circuit to the -
- alternate circuit,.
4.8.1.1.2 Each of the above required diesel generators shall be demonstrated OPERABLE: , .
In.accordance with the frequency specified in Table 4.,8.1.1.2-1 on a
,- a.
- j. STAGGERED TEST SASIS by: '
- 1. Verifying _the fuel level in the day tank.
- 2. Ver1fying the fuel level in the fuel storage tank.
[
2
- 3. Verifying the fuel transfer pump starts and transfers fuel from j the storage system to the day tank. ~
- 4. Verifying the diesel starts from ambient conditions and acceler-ates to at least 441 rpm for Div 1 and Div 2 and 882 rps for Div 3 in less than or equal to 10 seconds". The generator volt'ge a and frequency shall be 4160 2 420 volts and 60 1 1.2 Hz within 10 seconds" after the start signal.
- 5. Verifying the diesel generator is synchronized, loaded toih p'r -^ g ,
mW M&WielweW58&Mofor diesel generators Div 1 and D< v 2 ahd 2600%t'for'dieser generator Div 3 in less than or equal to 60 seconds", and operates with this load for at least 60 minutes.
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- 5. Verifying the diesel generator is aligned to provide standby power to the associated amargency busses.
- All diesel generator starts for the purpose of this Surveillance Re' quirement may be preceded by an engine prelube period, The diesel generator start (10 sec)/ load (60 sec) from ambient conditions shall be performed at least once per 184 days in these surveillance tests. All other engine starts for
. the purpose of this surveillance testing may be preceded by other warsup pro-cedures recommended by the manufacturer so that the mechanical stress and wear on the diesel engine is minimized.
U hbolis mea.r4 A pikca,4o weil roAne s ).J,,w, odARbs f PERRY - UNIT 1 3/4 8-4 W S O M 7tCDhu l . .
j a s ELECTRICAL POWER SYSTEMS l SUPNEILLANCE REQUIREMENTS (Continued) 1 --
g,
. for diesel generator Div 2, and greater than er equal to 2200 kw (HPCS pump) for diesel generator Div 3 while enintaining voltage at 4160 1 420 volts and frequency at 6011.2 Hz er nominal speed
( plus 75% of the difference between nominal speed and the over-
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speed trip setpoint or 15% above nominal, whichever is .less.
- 3. VaMMng the diesel generator capability to reject a load of g p%.wi]vkw for dieselDiv generators Div 1 andTheDif 2 and 2600 4 kw for T
us enerator 3 without tripping. generator shall not exceed 4784 volts for Div 1 and Div 2 and 5000 volts voltage
/
1 - for Div 3 during and following the load rejection.
- 4. . Simulating a loss of offsita power by itself, and:
i a) For divisions 1 and 2: ,
- 1) Verifying de-energization of the emergency busses and
.-load shedding from the emergency busses.
, 2) Verifying the diesel generator starts
- on the auto- '
,, start signal, energizes the emergency busses with per-
! sanently connected loads within 10 seconds, energizes- ,
the auto-connected loads through the load sequence (individual load timers) and operates for greater
) than or equal to 5 minutes while its generator is so loaded. After energization, the stesqy state voltage l
. and frequency of the emergency busses shall be main-
! tained at 4160
- 420 volts and 60 1 1.2 Hz during this l
test. ,
fr b) For division 3:
- 1) Verifying de-e'nergization of the emergency bus.
- 2) Verifying the diesel generator starts
- on the auto-start signal, energizes the emergency bus with the per-
'*_" sanently connected loads within 10 seconds and operates for greater than or equal to*5 minutes while its gen-erator is so loaded. After energization, the steady DAll diesel generator starts for the purpose af this Surve111doce Requirement may be preceded by an engine prelube period. The diesel generator start (10 sec)/ load (60 sec) from ambient conditions shall be performed at least once per 184 days in these surveillance tests. All other engine starts for _
the purpose of this surveillance tuting may be preceded by other warmup pro-cedures recommended by the manufacturer so that the mechanical stress and wear on the diesel engine is minimized.
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