Rift Chunks are a special property that allow a Minecraft Chunks to receive Artron Energy. It can be used to power Tardises and other Artron Energy machines.
Any chunk, at any time, will have a chance to become a rift. Rifts will have limited energy, and that will build overtime.
A fully drained rift will close and not gain any power again, but like every other chunk it has a chance to become a rift again.
When a Tardis lands in a chunk, if the chunk becomes a Rift Chunk, a notification of "Rift Detected!" will display on the Tardis Monitor Block.
These rift chunks will allow a Tardis that is parked inside the chunk to gain more energy when refuelling.
It will also facilitate the use of certain TARDIS-only, energy requiring items / machines.