Information Notice 1984-92, Cracking of Flywheels on Cummins Fire Pump Diesel Engines
SSINS No.:
6835 IN 84-92
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
D.C.
20555 December 17,
1984 IE INFORMATION NOTICE NO. 84-92:
CRACKING OF FLYWHEELS ON CUMMINS FIRE
PUMP DIESEL ENGINES
Addressees
All nuclear power reactor facilities holding an operating license (OL)
or
construction permit (CP),
research and test reactors, and fuel facilities.
Purpose
This information notice is to alert recipients of a potentially significant
problem of cracking flywheels on certain models of Cummins fire pump diesel
engines.
This cracking apparently becomes noticeable only after it has propa- gated through the thickness of the flywheel and appears on its outer surface.
It is expected that recipients will review the information for applicability to
their facilities and consider actions, if appropriate, to preclude similar
problems occurring at their facilities.
However, suggestions contained in this
information notice do not constitute NRC requirements; therefore, no specific
action or written response is required.
Description of Circumstances
Since December 12,
1933, LaSalle Cuunity Stdtion hds experienced repeated fatigue
cracking of flywheels on both of its Peerless Pump Co. fire pump diesel engines, Cummins Model No. NT-855-F2 equipped with flywheel Part No. 3453 (assembly no.
3023676).
The cracks appear to initiate on the engine side (blind side) of the
flywheel at a circumferential groove which intersects each crank shaft attach- ment bolt hole.
Cracks have been found to initiate after as little as 34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br />
of operation, but can only be detected with the use of a liquid penetrant.
The
initial development of these cracks is fast, but subsequent growth is slower
and there have been no catastrophic failures to date.
The cracking is believed
to be related to the response of the flywheel to inherent engine and gearbox
vibration and it appears to be generic to the flywheel design.
This problem was first discovered when a flywheel on an engine with 850 hours0.00984 days <br />0.236 hours <br />0.00141 weeks <br />3.23425e-4 months <br />
of operation had cracked through its thickness over 3600 of the circumferential
groove.
A second unit with approximately 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> of operation was found to
have had its flywheel cracked through its thickness over approximately 2700 of
the circumferential groove.
Both flywheels were replaced and a'6-month inspec- tion program was established.
At the end of the first 6-month period, a sur- face penetrant test was used and cracks were discovered on the engine side of
the flywheels on both units (one unit with 34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br /> of operation and the other
with 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />).
At this point it was decided to establish a program to inspect
the flywheels after 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br /> of operation.
~T~q
1A1
IN 84-92 December 17,
19B4 Cummins has discontinued the use of this flywheel and is currently using their
standard truck engine flywheel (Part Mo.
2965) on the NT 855 F4 fire pump
diesel.
They have been running comparison tests on these two flywheels (Parts
No. 2965 and No.
3453) and are considering recommending use of the truck engine
flywheel as a replacement for the flywheel that has the cracking~prohlem.
The
retrofit of the new flywheel (Part No.
2965) would require some modification
because of size differences in the stub shafts.
ThE following Cummins diesel fire pump engines that are equipped with flywheel
Part No. 3453 are:
NH 220 IF
N 855 F
NT 855 F1 NT 855 F2 No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact the Regional
Administrator of the appropriate NRC regional office or this office.
IE-dwa rVd
)/Jordan, Director
Divisio
and Engineering Response
Office of Inspection and Enforcement
Technical Contact:
Chauncey Gould
(301) 492-8597 Attachment:
List of Recently Issued IE Information Notices
Attachment
IN 84-92 December 17,
1904
LIST OF RECENTLY ISSUED
IE INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issue
Issued to
84-91
84-90
84-89
84-88
84-87
84-86
Quality Control Problem
of Meteorological
Measurements Problems
Main Steam Line Break
Effect on Environmental
Qualification of Equipment
Stress Corrosion Crac!-ing
in Nonsensitized 316
Stainless Steel
Standby Gas Treatment
System Problems
Piping Thermal Deflection
Induced by Stratified Flow
Isolation Between Signals
of the Protection System
and Non-Safety-Related
Equipment
Molybde im Breakthrough
from Te inetium-99m
Generators
Deficiencies In Ferro-
Resonant Transformers
Various Battery Problems
G uidance for Posting
Radiation Areas
12/10/84
12/7/84
12/7/84
12/3/84
12/3/84
11/30/84
11/30/84
11/27/84
11/19/84
11/19/84
All boiling water
reactor facilities
All boiling water
reactor facilities
All boiling water
reactor facilities
All boiling water
reactor facilities
All boiling water
reactor. facilities
All boiling water
reactor facilities
All NRC licensed
medical institutions
and radiopharmaceutical
suppliers
All boiling water
reactor facilities
All boiling water
reactor facilities
All boiling water
reactor facilities
84-85
84-84
84-83
84-82 OL = Operating License
CP = Construction Permit