IE Circular No. 80-05, Emergency Diesel-Generator Lubricating Oil Addition and Onsite Supply
SSINS No.: 6830
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
April 1, 1980
IE Circular No. 80-05
EMERGENCY DIESEL-GENERATOR LUBRICATING OIL ADDITION AND ONSITE SUPPLY
Description of Circumstances:
On January 17, 1980, the Kewaunee Nuclear Power Plant experienced a partial
loss of offsite power which resulted in a turbine trip, reactor trip, and
one emergency diesel engine driven generator (diesel-generator or D/G)
supplying power to one engineered safeguards bus. Offsite power continued
to supply the other engineered safeguards bus.
During the day before, on 1-16-80, this diesel-generator had successfully
completed a 24-hour loaded test run but had a low lube oil alarm condition
with oil level 1/2-inch low. The D/G was fully operational in this
condition. Before oil could be added on 1/17/80, the D/G was required for
emergency power following the failure of the reserve auxiliary transformer.
The normal oil fill location could not be used while the D/G was operating.
The D/G Technical Manual (TM) indicated that oil could be added with the
engine running, but did not describe the method to be used. Lube oil was
added by pumping into the engine through a pipe that was assumed to be a
lube oil line; this line was color coded in the TM and painted with the lube
oil system color code. Three barrels of oil were added via this line while
the D/G was operating. After transferring the emergency bus to off-site
power through the tertiary auxiliary transformer the D/G was shut down.
With the D/G shut down two more barrels of oil were added through this line
without increasing the sump level. Then two more barrels of oil were added
through a different addition point and the level was restored to normal.
The following day a factory representative determined that the first five
barrels of oil had been added to the engine air box through a mismarked
(should have been color coded as an air line) drain connection. Four and a
half barrels of oil were drained out after which the diesel-generator was
satisfactorily test operated. It is believed that the diesel engine could
have been damaged had an engine start been attempted while the five barrels
of oil were in the air box. Further, it is noted that procedures for adding
oil to the operating diesel engine were not available and that the personnel
performing the addition were not familiar with, nor trained on, how to add
oil to a running engine or how to verify that oil had been properly added.
This event brought to light an additional problem which may be generic.
During the previous day's test run of the diesel-generator lube oil
consumption was approximately 3 gal/hr. During the loss of power event, the
licensee had three barrels (165 gallons) of lube oil available onsite. The
IE Circular No. 80-05 April 1, 1980
Page 2 of 3
licensee's Technical Specifications require a seven day supply of fuel oil
for one diesel-generator be available onsite. To meet the intent of the
Technical Specifications, a seven day supply of lube oil should also be
The diesel engines are model 999-20 manufactured by the Electro-Motive
Division of General Motors Corporation. These diesel engines use a 2-stroke
cycle and lube oil consumption is normally higher than for the 4-stroke
cycle diesel engines. Vendor representatives and NRC consultants indicate
that lube oil consumption rate varies with engine condition and load.
Further, the 3 gal/hr consumption rate is considered to be in the normal
Recommended Action for Licensee's Consideration:
All holders of operating licenses for nuclear power reactor facilities
should be aware of the potential problems described above. Because of the
generic nature of these matters, it is recommended that the considerations
identified above be reviewed at your facility in the following respects:
1. Verify the existence and adequacy of procedures or instructions for
adding lubricating oil to safety related equipment. This should
include the following:
a) Whether or not, how and where lube oil can be added while the
equipment is in operation,
b) Particular assurance that the wrong kind of oil is not
inadvertently added to the lubricating oil system, and
c) That the expected rise in level occurs for each unit of lube oil
These operating procedures or instructions should be available locally
in the area of the affected equipment.
2. Verify that personnel are trained in such approved procedures and
demonstrate an ability for using these procedures to add oil while
the D/G is operating and that they understand how to verify that the
proper amount of oil has been added.
3. Verify that the color coded, or otherwise marked, lines associated with
the diesel-generator are correct and that the line or point for adding
lube oil has been clearly identified.
4. Verify that appropriate procedures or instructions exist, and personnel
are trained, on the proper addition of lube oil and the performance of
maintenance during operation of other similar vital equipment.
IE Circular No. 80-05 April 1, 1980
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5. Determine the lube oil usage rate for each diesel engine under full
load conditions including the rates considered to be excessive.
Provide adequate inventory of lubricating oil of the proper grade
consistent with the highest usage emergency diesel-generator(s)
operating for the time period specified in the plant Technical
Specifications for fuel oil supply. When lube oil consumption rates
become excessive, provisions should be included for overhaul of the
All holders of construction permits for nuclear power reactor facilities
should be aware of the potential problems identified above and initiate
appropriate procedures prior to initial fuel loading.
No written response to this Circular is required. If you require additional
information regarding these matters, contact the Director of the appropriate
NRC Regional Office.
Page Last Reviewed/Updated Thursday, March 25, 2021