the workers at the nuclear plant were evacuated. Official measures at Fukushima I reactor unit 1, however, show a rise in temperature following the aftershock and a spiking amount of radiation in the Dry Well, which exceeds the instrument maximum of 100 Sv/h. Gauge B, in the meantime, records a steady increase in pressure for the previous ten days in the same reactor. Reporting the rise to 100 Sv/h from the earlier 30 Sv/h, TEPCO declares that the "validity of the measurement is questioned" both for radiation levels and pressure. Friday, 8 April Before the crisis evaluation was elevated by Japanese authorities to level 7, the highest level, experts already recognized that Fukushima is the most complicated nuclear accident. {| class="wikitable collapsible collapsed plainrowheaders" |- style="border-bottom: 3px solid gray;" ! scope="col" style="border-right: 3px solid gray; width: 16%;" | ! scope="col" style="width: 14%;" | Unit 1 ! scope="col" style="width: 14%;" | Unit 2 ! scope="col" style="width: 14%;" | Unit 3 ! scope="col" style="width: 14%;" | Unit 4 ! scope="col" style="width: 14%;" | Unit 5 ! scope="col" style="width: 14%;" | Unit 6 |- | Fuel integrity | | | | | | |- | Reactor pressure vessel integrity | | | | | | |- | Containment integrity | | | | | | |- | Core cooling system 1 (ECCS/RHR) | | | | | | |- | Core cooling system 2 (RCIC/MUWC) | | | | | | |- | style="border-bottom:3px solid gray;"| Building integrity | | | | | | |- | Pressure vessel, water level | | | | | | |- | Pressure vessel, pressure (Two instrument trains) | | | | | | |- | Pressure vessel, temperature | | | | | | |- | style="border-bottom:3px solid gray;"| Containment pressure | | | | | | |- | Seawater injection into core | | | | | | |- | Seawater injection into containment vessel | | | | | | |- | style="border-bottom:3px solid gray;"| Containment venting | | | | | | |- | INES | | | | | | |- | Environmental effect | colspan="6" | Radiation levels: South side of office building: 650 µSv/hour at 8 April 15:00 JST Main gate: 94 µSv/hour at 8 April 15:00 JST West gate: 40 µSv/hour at 8 April 15:00 JST Levels of radioactive iodine 4,385 times higher than regulatory limits were detected in