What seems to be causing the spiking in levels is the venting of the reactors, either steam or other. After the ventingin, the level seems to drop. That dropping isn’t necessarily a sign of “normalization.”
Just heard on TV news that Japanese officials think #3 has a containment breach, and that #3 is where the spike is coming from..........I sure hope not, as #3 is the unit that uses MOX fuel (plutonium is part of fuel mix)............if it is #3, then millisieverts in the hundreds is very possible.........