According to authorities in Japan, the ambient radiation in and around the northeastern city of Sendai that suffered some of the worst effects of last week’s tsunami is down to the maximum permissible level of 0.2 microsievert per hour.
Further south on Honshu Island, including Tokyo, the levels are even lower.
At the Fukushima nuclear plant, meantime, engineers reports some progress in their efforts to cool the damaged reactors.
The tsunami is now known to have killed over 73 hundred people.
More than 11 thousand remain unaccounted for.