Ice

Ice is a translucent solid block  formed in snowy Biomes   from exposed water , and is slightly slippery.

Ice has an EMC value of 1. there is no way of mining ice currently in tekkit, but ice can be formed by compressing snowballs in a compressor.

Due to its transparency , ice cannot have  torches placed on it directly.

Ice will also melt into water if the light level immediately next to it on any side is sufficiently high (greater than 11), from light sources other than sunlight. Conversely, a water block in a snowy biome will eventually freeze into ice if exposed to the sky from directly above, and the light level immediately adjacent to the water block on all sides is sufficiently low (less than 13). This can happen at any time of day, and in any weather condition. If the highest adjacent light level is 12, an ice block will alternately melt and re-freeze when it receives a block tick.

Usage of ice in nuclear reactors

there aren't much uses of ice, but ice is extremely useful in cooling nuclear reactors.

NOTE: Minecraft 1.3.2 IndustrialCra​ft² has had a second re-write of the N uclear Reactor with additional components and removed environmental effects such as water and Ice cooling.

 this update makes Ice cooling(often known as SUC cooling) useless.