Selection and Structural Optimization of Fire-Resistant Cables for Nuclear Power Plants

To clarify characteristics of fire-resistant cables for nuclear power plants and support their selection and manufacturing, an analysis was conducted on their types, safety classifications, quality assurance grades, and structural designs. A comparison was made between different fire-resistance test standards (such as GB/T 19666—2019 and BS 6387: 2013), and structural verification tests were carried out to explore the impact of structures on performance. In terms of classification, fire-resistant cables for nuclear power plants mainly include fire-resistant low-voltage power cables, control cables, and measurement cables, with safety classifications such as Class 1E and non-Class 1E, and most quality assurance grades being Q2 and Q3. In terms of structure, fire-resistant layer is mainly made of mica tape, and the use of ceramic silicone rubber tape, extruded ceramifiable polyolefin, or halogen-free flame-retardant crusting polyolefin for the spray-resistant layer could improve the pass rate of NS fire resistance test specified in GB/T 19666—2019. Selection in different scenarios should be based on environmental characteristics, safety levels, and standard requirements. The study showed that reasonable structural design, appropriate material selection, and compliance with relevant standards could ensure the reliability of fire-resistant cables for nuclear power plants in complex environments, providing a reference for their selection and manufacturing.