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Ongoing Assessments
Chapter 2 Implementation Guidance for Operational Configuration Management
Periodic Equipment Performance Monitoring

identified in walkdowns. Vertical slice assessments are primarily diagnostic and would not generally
produce discrepancy resolutions or as-built documents.
Walkdowns. During walkdowns, the as-found configuration is identified by comparing the existing
physical configuration with the facility documentation to identify any discrepancies, typically by marking
up the documents. Appendix 11­C provides detailed guidance for conducting walkdowns. Walkdowns
are sometimes conducted to record manufacturers' nameplate data from equipment, to identify missing
or incorrect equipment labeling, to determine the present material condition of equipment, and to
identify potential physical interactions between equipment (such as non-seismically qualified equipment
mounted In such a position as to impact seismically qualified equipment during an earthquake).
Physical configuration assessments may be performed on a sample basis, with the sample providing a
representative cross-section of component types within the system being assessed. The sample should
be large enough to ensure that a statistically significant portion of the system and its components are
chosen. For instance, the sample should Include major and minor components, large and small bore
piping, and instruments and controls. Minimum thresholds for determining an acceptable number of
discrepancies should be established prior to walkdowns based on proven statistical techniques (e.g.,
similar to those used in quality programs for the selection of samples and the determination of
If the initial physical assessments confirm that the facility documents accurately reflect the physical
configuration, further physical configuration assessments should be included on a sample basis with
periodic program effectiveness assessments. However, if the initial physical assessments indicate that
substantive discrepancies exist (either in number or type) between the physical configuration and its
documentation, appropriate immediate corrective actions should be identified to establish agreement
between the physical configuration and the facility documentation.
The corrective actions for substantive discrepancies include additional walkdowns to characterize and
determine the extent of the problem. Sometimes the discrepancies can be isolated to certain systems,
certain modification vintages, or certain change mechanisms (modification processes). If the extent of
the problem can be limited, appropriate corrective actions can be directed at the root cause. Where
control of the physical configuration has been lost, walkdowns of every important system may be
necessary. In this case, a justification for continued operations may be necessary if continued
operations are desired.
As-Builting Process. As-builting is a process that involves determining the actual physical configuration
that exists at a point in time, identifying any discrepancies with the facility documentation, and
technically resolving those discrepancies. In some cases, discrepancies arise simply because the
facility documentation is incomplete or inaccurate in some details. In other cases, discrepancies arise
because inadequately controlled hardware changes caused the physical configuration to become
different from the facility documentation. The level of detail of a particular facility document type
establishes the threshold of the corrections that need to be made. If a facility document provides, or is
intended to provide, a level of detail that includes information that does not agree with the actual
physical configuration, those discrepancies should be identified and resolved. Leaving incorrect or
unverified information on a document is likely to mislead users of the document. Further, any
information that is left on as-found documents and has not been verified should be clearly identified.
The resolution of the as-found discrepancies needs a technical review to determine if the physical
configuration is correct (in accordance with the currently-approved design requirements) or if the facility
documentation is correct (the physical configuration is not correct). In some cases, the resolution of a
discrepancy might be to establish the acceptability of the existing physical configuration and change the
design requirements. Technical approval from the design authority (i.e., design verification) should be

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