MV cable testing in nuclear plants

[VLFit]

Are there requirements from somewhere, maybe the NRC, requiring nuclear plant operators to perform diagnostic or withstand testing on medium voltage shielded cable in nuclear plants? maybe partial discharge or tan delta or some of the other methods?

 

[racookpe1978]

Before installation (for product certification)? Or as-installed (insulation and connectivity checks?) or as-maintained/life-cycle extension testing?

Medium voltage meaning 440/480 VAC power and utility service cables to welders, heaters, fans, etc?

 

[VLFit]

Thanks for the response. Medium voltage cables 5 - 35 kV in rating. In the case of nuclear plants, most are probably rated for 5, 8, or 15 kV. The testing is usually done when installed, usually just an AC Withstand test to find defective installation locations or defective accessories. The testing is also performed over time as a maintenance test. Usually a diagnostic method, like Tan Delta testing, is done rather than a pass/fail overvoltage withstand test. They test all the cables, or a large portion, at one time, gather the data, and then make a comparative analysis of their results. From this they can determine where their priorities are for replacement or maybe injection. This is a common practice and I thought there was some directive to Nuclear plants to do this. Maybe not, but I thought I would throw the question out there. It's an important subject in the area of cable maintenance. Thanks

 

[vpl]

A bit of a late response. I believe that there is guidance from the NRC for testing of medium voltage cables on plants that have gone through license renewal. You might find some help at the NRC's site:

http://www.nrc.gov/reactors/operating/licensing/renewal.html

Patricia Lougheed

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