In the safety operation system of nuclear power equipment, ceramic fiber insulation boards serve as critical thermal insulation and protective materials, requiring performance standards far exceeding those of conventional industrial applications. The high-temperature, radiation, high-pressure, and sealing requirements of nuclear power environments impose special protective standards on ceramic fiber insulation boards, directly impacting the operational safety and service life of nuclear facilities.
High-temperature resistance and thermal stability are core requirements for ceramic fiber insulation boards used in nuclear power applications. During operation, the core areas of nuclear reactors and their auxiliary equipment can reach temperatures exceeding 800°C, with frequent temperature fluctuations. Therefore, ceramic fiber insulation boards must be capable of withstanding temperatures above 1000°C for extended periods and must not crack or collapse structurally under thermal shock conditions involving rapid temperature changes. Experimental data requires that after continuous exposure to 1200°C for 24 hours, the thermal shrinkage rate must be controlled within 1%, and the compressive strength retention rate must not be less than 90%, ensuring the integrity of the thermal insulation barrier under extreme temperature changes.
Radiation resistance is a special requirement in nuclear power applications. Nuclear radiation can cause changes in the molecular structure of materials, leading to performance degradation in traditional insulation materials. Nuclear-grade ceramic fiber insulation boards must be formulated with specialized oxide components to maintain stability under γ-ray and neutron radiation environments. After cumulative radiation testing at 10⁵ Gy, the thermal conductivity change rate of the ceramic fiber insulation board must not exceed 5%, and mechanical strength degradation must not exceed 10%, to prevent insulation failure due to radiation aging.
Sealing performance and chemical stability requirements are equally stringent. High-pressure media are present in cooling systems and steam pipelines of nuclear power equipment. Ceramic fiber insulation boards must have excellent sealing adaptability, with the gap between the board and the equipment surface controlled within 0.1 mm to prevent media leakage. Additionally, they must withstand long-term corrosion from media such as boric acid solutions and high-temperature steam. After being immersed in an environment with a pH value of 4–10 for 3,000 hours, the weight loss rate must not exceed 3%, and there must be no significant structural delamination, ensuring stable performance in complex chemical environments.
Furthermore, environmental and safety requirements are even more stringent. The volatile content of ceramic fiber insulation boards must be below 0.1% to prevent the release of harmful gases that could contaminate the nuclear environment at high temperatures. Additionally, the fiber diameter must be controlled between 3-5μm, and an asbestos-free formulation must be used to ensure that no health hazards are posed to personnel during installation and maintenance, in compliance with safety protection standards in the nuclear power sector.
These special protective requirements are driving technological upgrades in ceramic fiber insulation boards for the nuclear power sector, making them a critical material for ensuring the safe and stable operation of nuclear facilities and providing reliable thermal insulation protection for nuclear power equipment.
