The radiation emitted by nonvolatile materials still poses a big danger to workers or cleanup crews close to the plant , along with the released volatile elements such as cesium and iodine .
Conservative extrapolation of current technology suggests that match-book size removable hard disks ( or the equivalent nonvolatile memory chips ) will store about 60 megabytes each .
Many dangerous nonvolatile radioactive materials such as uranium tend to remain in the nuclear core . If a full meltdown occurs , they could liquefy , eat through containment structures and enter the close environment .