The British newspaper Morning Star reported today:
Rising black smoke forced another evacuation of workers trying to stabilise Japan’s radiation-leaking Fukushima Dai-ichi nuclear plant today.
A nuclear agency official said workers would not be allowed to return to the plant until the morning because of fresh outpourings of smoke from one reactor.
Other press reports indicate that the source of the smoke is the Unit 3 reactor building, although it is not clear if it is the reactor or the spent fuel pool that is burning. Either is problematic, as the Unit 3 reactor runs on mixed-oxide (MOX) fuel, which contains plutonium. The spent fuel pool holds spent MOX from reactor 3.