ML20010E673

Forwards Design/Test Info Re Piping Mods to Lube Oil Sys of Emergency Diesel Generators,Per Outstanding Issue 13 in Section 1.8.1 of Ser.Commitment for Design/Test Info Made, in Response to Licensing Question 222.48

ML20010E673
Person / Time
Site:	Fermi
Issue date:	08/31/1981
From:	Colbert W DETROIT EDISON CO.
To:	Kintner L Office of Nuclear Reactor Regulation
References
EF2-54-624, NUDOCS 8109080132
Download: ML20010E673 (6)

Text

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Deholt Edison sii!!!9 ret >e August 31, 1981 EF2 - 54,624

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Mr. L. L. Kintner 4 0 U. S. Nuclear Regulatory Commission C Office of Nuclear Reactor Regulation -

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Washington, D. C. 20555 r 9 G' s.s-s

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Reference:

Enrico Fermi Atomic Power Plant, Unit 2 NRC Docket No. 50-341

Subject:

Diesel Engine Lubrication Detroit Edison agreed to supply information regarding the manufacturer suggested piping modification to the lube oil system of the Emergency Diesel Generators. These modifications will help assure engine lubrication for all starts. The design and test information is provided in the attached Colt Industries Engineering Report (File Number VTS-985-082881-0IR).

This is associated with outstanding issue No, 13 in Section 1.8.1 of the Fermi 2 Safety Evaluation Beport.

The commitment for the design and test information was made in response to licensing question 222.48.

Sincerely, Yh.

W. F. Colbert Technical Director Enrico Fermi 2 Ol WFC:jl j Attachment cc: Mr. B. Little !If 8109000132 810831 PDR ADOCK 05000341 E PDR

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.uc ENGINEERING REPORT O7 [jt,,VTS-995-082881-01R Fairb:nks Morso _

En$na oms an NE Aur,uST 28, 1981

'" ENGINE PRELUBE/KEEPWARM SYSTEM REQUIREMENTS

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un2 NUCLEAR STANDBY UNITS (OP ENGINES) D,Uc/v. .,, k. 4 .:

GENERAL This report covers modifications to be made to the OP skidded engine units to provide an engine more readily prepared to make fast starts such as are required In the previous engine skid designs, the unit was provided in Nuclear service. lne one referred with two systems to precondition the engine lube oil system, to as the keepwan1 systen, consistel of a motor driven punp and a heater thru which a small flow of lube oil was run while the engine was not in operation. '

sump, thru the heater and back into the The oil was pumped fron the L.O.The heater was thermostatically controlled to attempt cpposite end of the sump. The other system consisted to maintain the L.0. sump at a moderate temperature.

of a somewhat larger capacity pump which was used inrediately prior to oper0 ting the engine to fill the engine with lube oil in preparation for an engine start.

This arrangement was used when ever the engine was started for testing or maintenance operations. In the event of a need for energency service, startup was made without prelubing the engine.

Research work was undertaken to see if it was possible to derive a system which would allew the engine to be continuously lubricated but not to the point of over-oiling the upper crankline. Work was done at a conmercial power plant having a skidded engine unit similar to those in nuclear applications to develop such a sy: tem. This report covers the results of that work and explains the modification to be acccmplished on nuclear units in the field.

RESULTS OF THE LEVELOPMEMTAL LORK

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Field testing was done that demonstrated that a system could be made to provide The oil flow to the engine while at rest without filling the upper crankline.

test work demonstrated that with a properly sized L.0. circulating pump, with the oil at the proper temperature, an oil level could be maintained somewhat With above the Icwer crankline, but below the level of the upper crankline.

such a system, oil was more readily available to the upper crankline upon fast startup of the engine. The leakage rate of the oil thru the bearings of the the main (engine driven) lower crankline, oil spitters, and return flow thn L.0. punp could be controlled by the oil temperature (viscosicy) However, to the point it of keeping the engine full to a level just above the lower crankline.

was discovered that if lube oil circulation was reinitiated immediately af ter the engine was shut down, without allowing some oil drainback fran the upper 9

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'" ENGINE PRELUBE/KEEPWARM SYSTEM REQUIREMENTS ,,,33m my V.T. STONEHOCKER KEEP'.!ARD L.O. SYSTEM MCDIFICATION 3,,, .

meron m NUCLEAR STANDSY UNITS (OP ENGINES) sg .4 crankline, the upper crankline could still be overfilled when the engine came to rest. It was demonstrated that if a period of 6 to 10 minutes was allowed l before circulation was conmenced, that the overfilling of the upper crankline could be prevented.

Figure 1 shows the final system arrived at resulting from this development program. In sumnary, the lube oil circulating system was modified so that oil was delivered to the system at a point near the engine driven pump discharge, thru a check valve. The L.0. circulating heater was increased in capacity from 6 to about 15KW in order to maintain L.0. temperature (viscosity) and to account for the greater losses in the L.O. system because of the increase in the extent of piping thru which the oil would then flow.

The selected changes to the system and engine are covered in two parts; modification of the systems external to the engine, and internal mcdifications.

The specific investigation enumerated here, covers the Alabama Power units (F.M. S.0. 205917 ) , but are generally also applicable to other similar units.

(Specific reports / instructions will be written for other contracts.)

MDIFICATIOff 0F THE EXTERNAL SYSTEM Investigation has shown that to adapt this system to the units at Alabama Power would require the following:

Mechanical (Ref: Figure 1)

Change the 6KW L.O. heater to 15KW. Infonnation from the most probable 1.

vendor indicates that a 15KW heater unit, not exceeding 15 watts per square inch of heater element, can be provided and can be accomodated on the skid The in place of the present heater, using the same mounting arrange'aent.

new unit is about the same size as the present J.W. heater. L.0. inlet would be at the same location.

2. Change the piping fran the discharge of the new heater to a point in the piping at the discharge of the engine driven pump (at the same location to which the prelube pump is now piped), including a check valve (same check valve as used with the prelube piping). Include a connection for location of the thennostatic switch (OHT) at the heater outlet. I 1/2" piping is required.

3. Block of f the cross to which the old connection was made (drain to front of L.0. sump) .

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• n ,t;lT S-935-082381-Ol R Fairbanks Morp Engine Divls!:n oArt #1 GUST 28, 1981

"'" ' ENGINE PRELUBE/KEEPWAR!! SYSTEM REqu!REMENTS parp3pm er V.T. ST0! EHOCKER 3ppaovro actoRT KEEPWARD L.O. SYSTEM MODIFICATION sr f. ,s, ,, ,. 3 .. .

N NUCLEAR STANDBY UNITS (OP ENGINES) -

e Electrical (Ref: Figure 2)

1. Relocate conduit to heater connection and thennostatic switch connection as required (raised approx.12").

2. Replace CB3 (20A) with a 50A unit (Same as CB1). (Our drawings do not indicate source on this item. Customer should identify circuit breaker unit manufacture so that it can be duplicated.)

3. Replace tG contactor with 11905926 (Cutler Hanner C200N3A) (Same as M1). ,

4. Replace wiring (3 wires each) between CB3 and M3 and between M3 and the heater (OH) with !8 AWG (was #12).

5. Add a Time Delay Relay - TDX (FM #11904628 - Agastat 7012AH) in the circuit as shown on the electrical schematic - Figure 2.

(One side of the coil to wire G, other side of coil to wire J7. One side of switch to wire J7 [ removing J7 from coil of fM]. New wire J7X between other side of switch [N.0. contacts] to coil of 14 (froa which wire J7 was removed.)

6. TDX has a range from 3 to 30 minutes and should be set at 10 minutes.

MODIFICATION TO INTERIOR OF ENGINE (Ref: Figure 3)

This modification consists of rerouting the supply to the upper L.0. header such that the header will not readily drain (a loop of tubing up over the crankshaf t above the level of the header). See Figure 3.

This modification also consists of adding a lube oil booster / accumulator system to the upper crankline, similar to that used on the af t lower main bearing. This booster system fills with oil during normal engine operation.

The next time the engine is started, the lube oil accumulated in the cylinder assembly is forced by starting air pressure acting on the opposite side of a piston, to be fed into the bearings along the upper crankline, thus filling the bearings with oil as the engine begins to be rotated in starting.

No exter::al connections are required with this system as the air supply to the accumulator is tied internally to that of the aft main bearing booster system. The system is self regulating.

Parts for this system are '.dentified on drawings and B/M #16403478 (Release PC3752).

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0.P. ENGINE Engine Driven L.0. Pump -L.0. Filter

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VALVE L.0. Cooler _ '3,,rainer P re-Lube . .

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j Y ^j f ew Connection f- FIGURE 1 - L.O. CIRC.

M , Original Connection U L.0. Temp Switc , ELEC TRICM. SYSTEM (Use existing) REF: 1186/037

- 1 1/2" piping (Rerouted)

L.O. HEATER -15KW (was 6KW)

KEEPWARM PU!'d - 10GPM (use existing)

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208 volt

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' ' CB4 CIRCUIT CR3 No Change BREAKER SOA (Was 20A)

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ENGINE PRELUBE/KEEPWARM SYSTE!1 P.ECUIREMENTs ratrants sr V.T. STONEHOCKER agar KEEPWARD L.O. SYSTEM MODIFICATION arracyt3 NUCLEAR STANDBY UNITS (OP ENGINES) er ,g. 4 ,

l g NEW SUPPLY PIPE JUMPER TO EACH UPPER MAIN BRG j[ _ ]. __ :L_ . h.

s UPPER LUBE OIL HEADER B00 STER SUFPLY - "O- ..

HEADER ( \ .j -f r

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upper crank i' SUPPLY LINE

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PREVIOUS SUPPLY PIPE

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ACCUMULATOR ,,

CYLINDER (BOOSTER) 1 2 gal. canacity PISTON-- '; C ,

(at rest) c W-> To A,f t Main hearing Booster Air supply from

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FIGURE 3 - ENGINE INTERNAL MODIFICATIONS LUBE OIL SUPPLY & B0OSTER SYSTEM se

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