Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C 20555
February 16, 1989
Information Notice No. 89-14: INADEQUATE DEDICATION PROCESS FOR COMMERCIAL-
GRADE COMPONENTS WHICH COULD LEAD TO COMMON
MODE FAILURE OF A SAFETY SYSTEM
Addressees:
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose:
This information notice is being provided to alert addressees to potential
problems resulting from an error made by a vendor in supplying a commercial-
grade component of the wrong size and an inadequate dedication process by the
licensee. It is expected that recipients will review the information for ap-
plicability to their facilities and consider actions, as appropriate, to avoid
similar problems. However, suggestions contained in this information notice
do not constitute NRC requirements; therefore, no specific action or written
response is required.
Description of Circumstances:
On July 7, 1988, during surveillance testing of the auxiliary feedwater pumps
at the Rancho Seco station, the outboard packing on the dual-drive auxiliary
feedwater pump overheated. The packing was replaced four times during the fol-
lowing month because it overheated during surveillance or post-maintenance
testing. The licensee then installed a packing supplied by a different vendor
which was satisfactorily tested on August 14, 1988.
Discussion:
A review of these events by the licensee showed that the last four sets of
packing supplied by the vendor were dimensionally incorrect and were installed
in the pump without any verification of the actual dimensions. This type of
problem has particularly significant safety implications because of the poten-
tial to cause a common mode failure of a safety system. The packing was
procured as commercial grade and upgraded for safety-related application by a
review of the packing's critical characteristics. Size was one of the
critical character-istics. However, the vendor considered the inside and
outside diameters to be proprietary information, and this restriction
contributed to the licensee's failure to perform an independent verification
of the dimensions. The licensee verified the size by looking at the invoice
for the packing and at the vendor's technical information. The vendor's error
could not be detected by this level
8902100199
. IN 89-14
February 16, 1989
Page 2 of 2
of verification. The documentation matched the purchase order; however, the
replacement packing was of the wrong size. In one of the four failures
reported, inadequate maintenance testing failed to uncover the vendor's error.
The packing did not overheat because the pump was not operated long enough.
The packing over-heated during subsequent operation of the pump.
Calculations by the licensee showed that in the event of a complete packing
failure, the pump still would have fulfilled its safety function. However,
the use of inadequately dedicated commercial-grade parts in nuclear facilities
significantly increases the probability that safety-related systems may not
perform their intended function.
The licensee intends to take additional precautions to accurately verify
critical characteristics of components before dedication. For instance,
the dimensions of the packing will now be measured directly and compared
to the shaft size. The licensee is also planning to increase the running
time for post-maintenance testing.
This event shows the importance in the dedication process to upgrade
components from commercial grade to safety-related applications of licensees
independently verifying the vendor's documentation. The event also
demonstrates the necessity of adequate post-maintenance equipment testing.
No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact the technical
contact listed below or the Regional Administrator of the appropriate regional
office.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contact: Daniele Oudinot, NRR
(301) 492-1174
Attachment: List of Recently Issued NRC Information Notices
.
Attachment
IN 89-14
February 16, 1989
Page 1 of 1
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
_____________________________________________________________________________
Information Date of
Notice No._____Subject_______________________Issuance_______Issued to________
89-13 Alternative Waste Management 2/8/89 All holders of NRC
Procedures in Case of Denial specific licenses.
of Access to Low-Level Waste
Disposal Sites
89-12 Dose Calibrator Quality 2/9/89 All NRC medical
Control licensees.
89-11 Failure of DC Motor-Operated 2/2/89 All holders of OLs
Valves to Develop Rated or CPs for nuclear
Torque Because of Improper power reactors.
Cable Sizing
89-10 Undetected Installation 1/27/89 All holders of OLs
Errors In Main Steam Line or CPs for BWRs.
Pipe Tunnel Differential
Temperature-Sensing Elements
at Boiling Water Reactors.
89-09 Credit for Control Rods 1/26/89 All holders of OLs
Without Scram Capability or CPs for test and
in the Calculation of the research reactors.
Shutdown Margin
89-08 Pump Damage Caused by 1/26/89 All holders of OLs
Low-Flow Operation or CPs for nuclear
power reactors.
89-07 Failures of Small-Diameter 1/25/89 All holders of OLs
Tubing in Control Air, Fuel or CPs for nuclear
Oil, and Lube Oil Systems power reactors.
Which Render Emergency Diesel
Generators Inoperable
89-06 Bent Anchor Bolts in 1/24/89 All holders of OLs
Boiling Water Reactor or CPs for BWRs
Torus Supports with Mark I steel
torus shells.
_____________________________________________________________________________-
OL = Operating License
CP = Construction Permit
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