NEW : Limit raised from 100 watts to 150 watts . TEPCO president apologizes . Nuclear official bursts into tears . U.N. nuclear tests : No harmful radiation is detected at any of 47 sites .
NEW : Limit raised from 100 millisieverts to 150 millisieverts . TEPCO president apologizes . TEPCO official bursts into tears . U.N. nuclear agency : No harmful radiation is detected at any of 47 sites .