Vitrea

This atomic powered woman of dark glass has awesome strength, but must be very careful when using her power, as a break in her glass skin would result in a release of radioactivity, killing all within a wide radius.

Navy Lieutenant Hannah Rose accompanies a shipment of nuclear waste to Hanford, where it's to be vitrified; encased in glass for safe storage. A terrorist group attacks, intending to capture the waste for use in a dirty bomb. Hannah sacrifices herself to stop them, and falls into the molten glass. Miraculously still alive, she becomes a being of dark volcanic-like glass surrounding a radioactive core.