also indicating higher than normal level." [ 57 ] Dose or dose-equivalent rates recorded on the main gate rose from "69  n Gy /h" (for gamma radiation, equivalent to 0.069  µ Sv /h) at 04:00 JST, 12 March, to "866 nGy/h" (equivalent to 0.866 µSv/h) 40 minutes later, before hitting a peak of