Information Notice 2009-11, NSP000059-Revised Prefiled Testimony of Northard/Petersen/Peterson-NRC Information Notice 2009-11
ML091240039 UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, DC 20555-0001
July 7, 2009
NRC INFORMATION NOTICE 2009-11:
CONFIGURATION CONTROL ERRORS
ADDRESSEES
All holders of operating licensees for nuclear power reactors under the provisions of Title 10 of
the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and
Utilization Facilities, except those who have ceased operations and have certified that fuel has
been permanently removed from the reactor vessel. All holders of and applicants for nuclear
power plant construction permits under the provisions of 10 CFR Part 50.
PURPOSE
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to inform
addresses of recent configuration control errors, particularly those that occurred during an event
at Prairie Island Unit 1 in which a turbine-driven auxiliary feedwater (AFW) pump was rendered
inoperable by a mispositioned valve. 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 IN are not NRC requirements; therefore, no specific
action or written response is required.
DESCRIPTION OF CIRCUMSTANCES
Prairie Island Nuclear Generating Plant Unit 1 - Loss of Turbine-Driven AFW Pump
On July 31, 2008, following an inadvertent reactor trip of Prairie Island Unit 1, the turbine-driven
AFW pump automatically started as designed but tripped 42 seconds later on low discharge
pressure. The licensee found the turbine-driven AFW pump trip resulted from a mispositioned
(closed) isolation valve for the discharge pressure switch. A time delay in the pump protective
circuitry is designed to trip the pump when a continuing low discharge pressure condition exists.
Monthly surveillances to test the operability of the turbine-driven AFW pump do not test the low
discharge pressure trip function of the pump as the pump is tested in the manual operating
mode, which bypasses the low discharge pressure trip. The licensee determined that sometime
between March 11, 2008, and July 31, 2008, the isolation valve for the discharge pressure
switch was closed rendering the turbine-driven AFW pump inoperable.
The licensee determined that the cause for the improper isolation of the turbine-driven AFW
pump discharge pressure switch was the failure to adequately control components that affect
safety related equipment. Specifically:
The mispositioned valve was not labeled, bypassing barriers normally in place to assist
in proper component identification.
NSP000059 The mispositioned valve was not locked in the required position, making mispositioning
more likely. The procedure aligning the AFW system does not define which valves shall
have locks, blocks or lock wires installed.
The procedure for component blocking or locking contains a definition of what
components should not be controlled, but does not contain a definition of which
components should be controlled.
Licensee corrective actions for this event included the following:
Conduct a review to identify all other components that could affect operability of
safety-related systems. Establish that each identified component is included in the
equipment database and drawings, has a locking device installed, and is labeled in the
field.
Lock-wired open the suction and discharge pressure switch manifold isolation valves for
all four AFW pumps.
Revise the procedure for component locking and blocking.
Additional information is available in Prairie Island Nuclear Generating Plant - NRC Special
Inspection Report 05000282/2008008; 05000306/2008008, dated November 7, 2008, and can
be found on the NRCs public website in the Agencywide Documents Access and Management
System (ADAMS) under Accession No. ML083120510. This event was also the subject of
Prairie Island Licensee Event Report (LER) 50-282/2008-003, dated September 29, 2008 (ADAMS Accession No. ML082730902).
Other Recent Configuration Control Error Events
The NRC Operating Experience Branch reviewed recent mispositioning events that were the
subject of NRC inspection findings and LERs. A listing and brief description of each of these
NRC inspection findings and LERs is publically available in ADAMS under Accession No.
The recent events show that component mispositionings have occurred or remained undetected
due to one or more of the following causal factors:
Failure to use or establish administrative controls, including: proper component labeling, proper valve locking, use of valve checklists, work and testing procedures use of post- maintenance flow testing confirmation (when necessary)
Dependence on a single administrative control to prevent valve mispositioning events
Insufficient training (lack of refresher training) or experience in determination of valve
position by individuals, (such as using rising stem position to help confirm valve position)
Improper independent verification or incorrect valve locking techniques
Lack of operator awareness of unique valve design or valve operating characteristics
Unrecognized operator burdens that increase the likelihood of error
Failure to effectively apply station and industry operating experience Corrective actions taken by some licensees for preventing configuration control errors include:
Label components with a unique plant equipment number and name ensuring they are
consistent with the designations used in plant procedures, drawings, and labels on the
operating controls.
Provide initial and periodic refresher training of operators, maintenance, and supervisory
personnel related to configuration control.
Use the corrective action program to track and trend configuration control errors.
Discuss site and industry operating experience and use operating experience feedback
mechanisms.
As procedures are performed, identify incorrect procedural steps or improper valve
labeling so that they can be corrected.
BACKGROUND
Previous NRC Generic Communications Involving Configuration Control
NRC IN 97-14, Assessment of Spent Fuel Pool Cooling, notes that ineffective configuration
control was the most frequent cause of spent fuel pool loss-of-inventory events and loss of
spent fuel pool cooling events. This IN is available under ADAMS Accession No.
NRC IN 98-34, Configuration Control Errors, discusses configuration control errors involving
the emergency diesel generator system noting that the potential exists for similar problems to
occur in other systems. This IN is available under ADAMS Accession No. ML031050070.
NRC IN 2007-11, Recent Operator Performance Issues at Nuclear Power Plants, provides
examples of improper alignment of the AFW system and is available under ADAMS Accession
No. ML070440238.
DISCUSSION
Configuration control errors, such as the mispositioning of valves or switches, can result in
technical specification required systems being rendered inoperable and can complicate
recovery actions following plant transients. Proper configuration control is particularly important
for those single components that, if mispositioned, would render the system inoperable. From
this group of important single components, proper configuration control is especially important
when the mispositioned component would not be readily detected because (a) there is no alarm
or other condition to alert the operators of the error, (b) the component is in a flow path that is
not testable by surveillance procedures or (c) due to unique conditions the mispositioning may
not be detected during routine surveillance testing. This example (c) was illustrated in the
Prairie Island event where a mispositioned valve rendered an AFW system train inoperable and
was not revealed during monthly surveillance testing. As a corrective action, the licensee
established a configuration control measure to lock wire the valves in the correct position.
CONTACT
This IN requires no specific action or written response. Please direct any questions about this
matter to the technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
/RA/
Timothy J. McGinty, Director
Division of Policy and Rulemaking
Office of Nuclear Reactor Regulation
Technical Contact:
Mark King, NRR/DIRS
301-415-1150
E-mail: Mark.King@nrc.gov
Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections.
CONTACT
This IN requires no specific action or written response. Please direct any questions about this
matter to the technical contact listed below or the appropriate Office of Nuclear Reactor
Regulation (NRR) project manager.
/RA/
Timothy J. McGinty, Director
Division of Policy and Rulemaking
Office of Nuclear Reactor Regulation
Technical Contact:
Mark King, NRR/DIRS
301-415-1150
E-mail: Mark.King@nrc.gov
Note: NRC generic communications may be found on the NRC public Web site, http://www.nrc.gov, under Electronic Reading Room/Document Collections.
Distribution:
IN r/f
ADAMS Accession Number: ML091700188
OFFICE
IOEB
TECH EDITOR
IOEB
BC:SBPB:DSS
ABC:IOEB:DIRS
D:DIRS
NAME
MKing
KAzariah-Kribbs
LFields
SGardocki
EThomas
FBrown
DATE
06/10/09
06/11/09 e-mail
06/11/09
06/11/09
06/11/09
06/22/09 OFFICE
PGCB:DPR
PGCB:DPR
BC:PGCB:DPR
D:DPR
NAME
DBeaulieu
CHawes
MMurphy
TMcGinty
DATE
06/19/09
06/22/09
07/01/09
07/07/09
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