A Study on the Fire Retardant Performance Depending on Accelerated Degradation of Non-Class 1E Cable

In nuclear power plants (NPPs), cables have an important role to operate and control safe-shutdown equipment and also cables are main contributor of fire loads in NPPs. For this reason, fire retardant performance of cables in NPPs shall be verified in accordance with IEEE-383 which endorsed in NUREG- 0800, "Standard Review plan for the Review of Safety Analysis Reports for Nuclear Power Plants". The methodology for flame test of Non-Class 1E cable needs to be developed to verify the fire retardant performance during life time. In this study, flame retardant performance of Non-Class 1E cables for aged conditions is verified and suggests the suitable methodology of flame test for NPPs. Flame tests with accelerated aging conditions for Non-Class 1E cables used in NPPs were conducted as described above. Cables were tested in accordance with IEEE-383(1974). The result of this study shows that the average length of cable damaged for aged condition is longer than those of cable for the unaged condition. However the significant relationship between aged cables was not found. The aging effect of cable on fire retardant performance is found by this study.