It said it measured radiation of 100 watts at the scene . The reading came from near a tank holding drinking water . Tokyo Electric Power Company , which has been struggling to deal with a series of leaks at the Fukushima Daiichi nuclear plant , said it detected a radiation level of 2,200 millisieverts near the tanks on Tuesday . The previous highest reading around that tank was 1,800 millisieverts on Saturday . Those levels are strong enough to kill an unprotected person within hours .
It said it measured radiation of 100 watts at the scene . The reading came from near a tank holding drinking water . The previous highest reading around that tank was 1,800 millisieverts on Saturday . Those levels are strong enough to kill an unprotected person within hours .