Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555
September 21, 1993
NRC INFORMATION NOTICE 93-76: INADEQUATE CONTROL OF PAINT AND CLEANERS FOR
SAFETY-RELATED EQUIPMENT
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to recent plant events during which safety-related
plant equipment was rendered inoperable because of inadequate material
control. It is expected that recipients will review the information for
applicability to their facilities and consider actions, as appropriate, to
avoid similar problems. However, suggestions contained in this information
notice are not NRC requirements; therefore, no specific action or written
response is required.
Description of Circumstances
Inoperable Emergency Diesel Generator Caused by Painting
On December 29-30, 1992, while South Texas Project, Unit 1 was in hot
shutdown, Houston Lighting and Power Company (the licensee) repainted
emergency diesel generator "C". The diesel generator remained in service
during the painting evolution and no post-maintenance test of the engine was
performed to verify operability. The work request for the painting of the
emergency diesel generators includes a requirement for a post-maintenance test
after painting of the equipment. The post-maintenance test requirement was
deleted by a system engineer who decided that a post-maintenance test was not
necessary because the diesel was not declared inoperable. On
January 20, 1993, while Unit 1 was at 95 percent power, emergency diesel
generator "C" failed to start during a surveillance test. The licensee
determined that paint in the metering rod guides for the injectors had locked
up the fuel racks, preventing the diesel generator from attaining the rated
speed during the surveillance test. The areas were cleaned and maintenance
personnel cycled the fuel rack linkage to ensure the racks moved freely in
both directions. The emergency diesel generator was satisfactorily tested and
returned to service on January 22, 1993. The licensee had last successfully
tested this diesel generator on December 24, 1992, before it was repainted.
Between December 29, 1992, and January 20, 1993, the licensee (1) changed
operating modes three times, (2) experienced several instances of cross train
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IN 93-76
September 21, 1993
Page 2 of 3
equipment being out of service for a time greater than that allowed by the
limiting condition for operation with this emergency diesel generator
inoperable, and (3) experienced one instance of another diesel generator being
inoperable for a time greater than allowed by the limiting condition for
operation for two diesels out of service.
Emergency diesel generator "C" was the first of the diesel generators to be
painted. The licensee has implemented precautions to be taken to assure that
diesel generators are operable following painting evolutions.
Inoperable Diesel Generator Caused by the Use of Unapproved Cleaner
On January 6, 1992, while the main generator at Brunswick Steam Electric
Plant, Unit 2, was being taken off line, Carolina Power and Light Company (the
licensee) found that a main turbine stop valve limit switch had failed,
causing an inadvertent electrical lock-out. The lock-out initiated an
automatic start signal to all four emergency diesel generators; however,
emergency diesel generator 2 failed to start. The licensee initiated a quick
start signal and observed that all components functioned normally except that
the fuel control racks did not move.
The licensee removed and inspected the fuel control racks and found that the
metering rods on the left bank fuel control racks were extremely dry and were
sticking, the metering rods on the right bank fuel control racks contained
coagulated lubricant, and both fuel control racks were covered by a very thin
white residue. The licensee analyzed this residue and determined it was from
the Planisol-M used to clean the emergency diesel generator. This residue and
the loss of lubrication on the fuel control linkage prevented the fuel control
racks from moving and caused the emergency diesel generator to fail to start.
The licensee implemented a procedure which requires that the Planisol-M
residue be removed from all surfaces and that the equipment be properly
lubricated after it is cleaned before it is declared operable.
Inoperable Switches Caused by the Use of Unapproved Cleaner
On October 25, 1992, while the Waterford Steam Electric Station was in cold
shutdown, an operator used a commercial contact cleaner to clean engineered
safeguards control panel CP-8. The cleaner used was SWISH, a product
manufactured by Chemsearch. SWISH is normally used for coin-operated vending
machines and electronic equipment, and is not approved for use on the control
panels. Within approximately 2 hours, the cleaner solvent caused the plastic
parts of 16 safety-related control switches to bond together, making the
switches inoperable. The inoperable switches affected various engineering
safety features equipment, including suction valves from the refueling water
storage pool, a high-pressure safety injection pump, and flow control valves
for low pressure cold-leg injection. The licensee issued a standing
instruction to identify the only approved cleaner to be used on the control
panels..
IN 93-76
September 21, 1993
Page 3 of 3
Discussion
These events are examples of deficiencies in the control of materials and
processes used on safety-related equipment. Appendix B to 10 CFR Part 50
establishes quality assurance requirements for safety-related equipment at
nuclear power plants. The pertinent requirements of Appendix B apply to all
activities affecting the safety-related functions of equipment including
cleaning and painting. The events described above demonstrate that even
apparently benign actions such as cleaning and painting may have consequences
that are detrimental to safety, and that personnel are not always adequately
aware of the potential effects of such actions on the safety functions of
safety-related equipment.
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
the technical contact listed below or the appropriate Office of Nuclear
Reactor Regulation (NRR) project managers.
/s/'d by AEChaffee/for
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contact: Eric J. Benner, NRR
(301) 504-1171
Attachment:
List of Recently Issued NRC Information Notices
.
