Abstract
Service lifetime estimates for nuclear medium voltage (MV) cables in nuclear power plants often do not match the actual performance lifetime in service conditions, particularly under immersion. With the majority of submerged MV cable insulation in NPPs being EPR and XLPE, a study was done to determine thermally aged EPR lifetime. However, with 34 EPR insulation failures reported within 30 years of installation, their 300-year predicted lifetime does not match the later survey.1,3 Current lifetimes are estimated using various accelerated ageing tests mostly dry, but these tests are not tuned for the material in its specific application, which may experience a range of environmental factors that change the modes or kinetics of degradation. This paper outlines a testing procedure utilizing different environments to expand more accurate life estimates on the effects of cyclic and permanent immersion in water, Harrison solution, and copper sulfate on polypropylene and polyethylene at elevated temperatures. Current results after 16 weeks suggest immersion and cycling show greater UTS impact. After further analysis and more tests, this research will propose either a correlation between the lifetime estimate of dry-aged polypropylene and polyethylene to cycled and immersed polypropylene and polyethylene or advocate for additional time or research correlated with electrical properties.
| Original language | English (US) |
|---|---|
| Pages | 906-913 |
| Number of pages | 8 |
| State | Published - 2019 |
| Event | 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg 2019 - Boston, United States Duration: Aug 18 2019 → Aug 22 2019 |
Conference
| Conference | 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg 2019 |
|---|---|
| Country/Territory | United States |
| City | Boston |
| Period | 8/18/19 → 8/22/19 |
Bibliographical note
Funding Information:This work was supported in part by the DOE Office of Nuclear Energy NEUP award DE-NE0008540. This manuscript has been co-authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan. (http://energy.gov/downloads/doe-public-access-
Publisher Copyright:
© 2019 19th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, EnvDeg. All rights reserved.