There is release of hydrogen from intentional venting of the reactors to relieve pressure. And there is probable damage to the unit #2 pressure control ring, the torus or wet well, which also released hydrogen.
I am not being mindless here or fear-mongering...but repeating what has been said. Going too far either way...into mindless fear or stupid poohing all is under control is crap either way. You can only deal with what is being said at this point and try and understand it.
And if the panic other gov. officials have shown in the last few days does not get your attention that something very bad is or has been happening then nothing will.