Comment by graypegg

I don't think they claim the mold removes radioactive material, but that it absorbs a high amount radiation since it's producing so much melanin, and seems to be fine. Since it's absorbing so much, it works like a radiation shield, kind of like lead.

So "eat" was a bit of a poetic choice for the title really haha. It "eats" energy. Pretty good deal for the mold considering the radiation is going to be produced whether they "eat" it or not, for a VERY long time!