Abstract
In a nuclear power plant environment, low-voltage cables experience different stresses during their service life which challenge their integrity. A non-destructive and reliable condition monitoring technique is desired to determine the state of these low-voltage cables during service and for the life extension of nuclear power plants. Hence, in this research work, an EPR/CSPE-based low-voltage cable was exposed to γ-rays for five different absorbed doses. The overall behavior of the cable under stress was characterized by frequency and time domain electrical measurements (capacitance, tan δ, and Extended Voltage Response) and a mechanical measurement (elongation at break). Significant variations in the electrical parameters were observed, as was a decline in the elongation at break values. A strong correlation between the measurement methods was observed, showing the ability of the electrical methods to be adopted as a non-destructive condition monitoring technique.
Highlights
This paper is a continuation of the work published in papers focusing on the investigation and implementation of non-destructive condition monitoring (CM) techniques for low-voltage (LV) nuclear power plant (NPP) cables [1,2]
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This paper investigated the overall degradation of ethylene-propylene rubber (EPR)/CSPE-based LV NPPs cable due to irradiation
Summary
This paper is a continuation of the work published in papers focusing on the investigation and implementation of non-destructive condition monitoring (CM) techniques for low-voltage (LV) nuclear power plant (NPP) cables [1,2]. The insulation and jacket of the cables are based on polymer materials and on a combination of different additives and fillers to improve their mechanical, electrical, and fire-retardant properties. Radiation stress with the presence of oxygen gives a peculiar aspect to the degradation problem as the molecular structure of the polymer is affected significantly; the macroscopic properties of the polymer are influenced, a topic which has been investigated for many years in different aspects [7,8,9,10]. Energies 2021, 14, 5139 properties of the polymer are influenced, a topic which has been investigated for 2moaf n16y years in different aspects [7,8,9,10]. TThhee ttwwoo--ccoorree ccaabbllee hhaaddiinnnneerrEEPPRRininssuullaattiioonn,, wwiitthh tthheetthhiicckknneessssoofftthheeininssuulalattiioonnbbeeiningg 00..7766 mm and tthheerraaddiuiussoof fthtehecocnodnudcutcotro0r.703.723m2 mm.mT.heTohueteorujtaecrkjeatcokfethoefctahbelecawbales cwoamscpoomsepdosoefdCoSfPECSwPiEthwanithexatnerenxatledrniaaml detiearmoeft1er2.o5fm1m2.5. Five cable samples were used for the study, and the Energies 2021, 14, x FOR PEER REVIEW
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