Monitoring Cable Condition During License Extension

Many utilities have made commitments to establish inspection programs for monitoring the condition of non-EQ cables during their extended operating license period.  The reason behind these commitments is simple.  Cable integrity is very important to the safe operation of the electrical circuits within a nuclear power plant,  especially when you consider that the circuit components will see 40+ years of use .

Visual inspections may not tell the whole story

The approach embodied within each cable monitoring program varies from utility to utility.  Some programs rely on simple visual inspections of the cable jacket material  to look for damaged areas.  While other programs are more complex, they combine visual inspections and electrical testing to provide a more complete picture of the cable condition.

Visual inspections, like those conducted during walk-downs, are very common within the industry, but the results may not provide enough information about a circuit’s condition.   For example,

  • It may be difficult to apply a predefined set of acceptance criteria because the interpretation of an observation is subjective and is often based on the inspector’s experience.
  • It could difficult for system engineers to relate the appearance  of the cable jacket to age-related degradation of a cable’s insulation material.
  • It may be difficult to trend test results between inspections because the results are qualitative rather than quantitative.
Example of a Damaged Cable Jacket
Example of a Damaged Cable Jacket

Electrical tests, like the ones performed by the ECAD System 2002, can provide valuable information about the condition of the dielectric material, the conductor(s) and shielding.  Data such insulation resistance, capacitance, dissipation factor, and time domain reflectometry (TDR) provide valuable quantitative information about the conductor(s), the dielectric insulation, and the cable insulation.

Please contact CM Technologies to learn about how our cable test technology can improve your existing cable inspection programs.

 

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