Why monitor sensor drift?
This is a proactive approach to ensure that actual sensor drift performance in
the field is bounded by the drift limits in the engineering analysis. Using
this key component provides tangible reports and evidence that can be used to
demonstrate to management, INPO, auditors and the NRC that your instrument
performance is meeting the safety analysis limits as well as the station
licensing and design basis requirements.
Why do I need drift analysis and what is being analyzed?
Post calibration of a sensor in the program, the data is entered into the Drift
Monitorin Software. The drift is then automatically calculated and compared to
the drift limit that is flagged if this limit is exceeded. The deficiency is
then documented in the corrective action program for an engineering evaluation.
The drift is evaluated against the licensing and design basis including any
applicable uncertainty calculations referenced in the program. Negative trends
are identified and past history is compare to the current data set. A graded
approach is used to develop a recommendation for acceptability or replacement.
This evaluation is documented in the corrective action program creating a
running history