Development of flame retardant AP cables for nuclear power plants

For flame retardant electric wires and cables, the nonpolluting property that the disaster due to harmful gas and smoke arising in combustion does not occur is required as well as the flame retardant property. Halogenous flame retardant materials which have been the main coating materials for conventional flame retardant electric wires and cables become the major cause of pollution, therefore, it has been proposed to avoid halogen. For the electric wires and cables laid in nuclear power stations, besides these requirements, the environment resisting property being able to adapt to the use in the special environment of heat, radiation, steam and so on is necessary. The highly flame retardant AP cables for nuclear power use reported in this paper use a cross-linked polyethylene material which is flame retardant but is not halogen, and these cables satisfy all the requirements for the electric wires and cables for nuclear power stations. The problems of halogenous flame retardant materials, the behavior of flame retardation, and the characteristics of highly flame retardant AP cabl-s for nuclear power use are reported. (Kako, I.)