ECOCIDE
noun
destruction of the natural environment,
especially when deliberate.

FUKUSHIMA NUCLEAR DISASTER

(March 11, 2011 – Japan)

Tōhoku Tsunami Impact

(Fukushima Daiichi)

The Official Story

FUKUSHIMA DAIICHI NUCLEAR ACCIDENT

Background

At the time of the Tōhoku earthquake on 11 March 2011, Reactors 4, 5, and 6 were shut down in preparation for re-fueling. However, their spent fuel pools still required cooling.

Initial effects of earthquake

The 9.0 M_wearthquake occurred at 14:46 on Friday, 11 March 2011, with the epicenter near Honshu, the largest island of Japan. It produced maximum ground g-forces of 0.56, 0.52, 0.56 at units 2, 3, and 5 respectively. This exceeded the seismic reactor design tolerances of 0.45, 0.45, and 0.46 g for continued operation, but the seismic values were within the design tolerances at units 1, 4, and 6.

When the earthquake struck, units 1, 2, and 3 were operating, but units 4, 5, and 6 had been shut down for a scheduled inspection. Immediately after the earthquake, the electricity-producing Reactors 1, 2, and 3 automatically shut down their sustained fission reactions by inserting control rods in a safety procedure referred to as a SCRAM, which ends the reactors’ normal running conditions, by closing down the fission reaction in a controlled manner. As the reactors were now unable to generate power to run their own coolant pumps, emergency diesel generators came online, as designed, to power electronics and coolant systems. These operated normally until the tsunami destroyed the generators for Reactors 1–5. The two generators cooling Reactor 6 were undamaged and were sufficient to be pressed into service to cool the neighboring Reactor 5 along with their own reactor, averting the overheating issues the other reactors suffered.

Arrival of tsunami

The largest tsunami wave was 13–14 m (43–46 feet) high and hit approximately 50 minutes after the initial earthquake, overwhelming the plant’s ground level, which was 10 m (33 ft) above the sea level. The moment of impact was recorded by a camera.

Disabling of emergency generators

The waves flooded the basements of the power plant’s turbine buildings and disabled the emergency diesel generators at approximately 15:41. TEPCO then notified authorities of a “first-level emergency”. The switching stations that provided power from the three backup generators located higher on the hillside failed when the building that housed them flooded. All AC power was lost to units 1–4. All DC power was lost on Units 1 and 2 due to flooding, while some DC power from batteries remained available on Unit 3. Steam-driven pumps provided cooling water to reactors 2 and 3 and prevented their fuel rods from overheating, as the rods continued to generate decay heat after fission had ceased. Eventually these pumps stopped working, and the reactors began to overheat. The lack of cooling water eventually led to meltdowns in Reactors 1, 2, and 3.

Further batteries and mobile generators were dispatched to the site, but were delayed by poor road conditions; the first arrived at 21:00 11 March, almost six hours after the tsunami struck. Unsuccessful attempts were made to connect portable generating equipment to power water pumps. The failure was attributed to flooding at the connection point in the Turbine Hall basement and the absence of suitable cables. TEPCO switched its efforts to installing new lines from the grid. One generator at unit 6 resumed operation on 17 March, while external power returned to units 5 and 6 only on 20 March.

Source: Wikipedia