Tokyo Electric Power Co. reported its second deadly radiation reading in as many days at its wrecked Fukushima nuclear plant north of Tokyo.

The utility known as Tepco said yesterday it detected 5 sieverts of radiation per hour in the No. 1 reactor building. On Aug. 1 in another area it recorded radiation of 10 sieverts per hour, enough to kill a person “within a few weeks” after a single exposure, according to the World Nuclear Association.

Radiation has impeded attempts to replace cooling systems to bring three melted reactors and four damaged spent fuel ponds under control after a tsunami on March 11 crippled the plant. The latest reading was taken on the second floor of the No. 1 reactor building and will stop workers entering the area. [bloom]