TMI vented a very large amount of radioactive krypton. (Given its density, it would better be described as dumped to the river, where it spread out along the banks downstream, gassing riverfront neighborhoods.)

Fukushima's containment exploded in hydrogen detonations, and vented a great deal of radioisotopes. They are today flushing tritium to the ocean, which seems wasteful; we will want the 3He that decays to.