Machinery Safety 101

Reflections on Fukushima

The Lessons from Fukushima

It’s now almost three months since the earth­quake and tsunami hit Japan’s north­east coast on 11-March. Recently, IEEE Spec­trum’s Eliza Strick­land inter­viewed Tsun­eo Futami, Super­in­tend­ent of the Fukushi­ma Dai Ichi plant from 1997 to 2000, on the events at Fukushi­ma fol­low­ing the tsunami…

Futami: … TEP­CO’s civil engin­eer­ing group estim­ates the max­im­um tsunami risk and max­im­um earth­quake risk for each power plant site. I was informed the max­im­um tsunami at the Fukushi­ma Dai‑1 site might be 10 meters. The tur­bine build­ings and the react­ors were built 10 meters above the sea level, so it is bey­ond my ima­gin­a­tion that sea­wa­ter flowed into the tur­bine build­ings of all units, and that facil­it­ies on the base­ment floor were flooded. …

The fact that TEPCO had already estim­ated that there was a like­li­hood of a 10 meter tsunami at this site and yet allowed the sea­wall to be built only 5.7 meters high raises some ser­i­ous ques­tions in this read­er­’s mind. Even with the tur­bines and react­ors built above this level, the crit­ic­al final stages of the cool­ing sys­tem were in the sea­ward yard, pro­tec­ted by a sea­wall that was little more than half as high as it needed to be. New inform­a­tion shows that the actu­al tsunami height may have topped 15 meters, three times the height of the sea­wall at the plant, and 5 meters high­er than the tur­bines and backup generators.

I think that the Fukushi­ma nuc­le­ar dis­aster should be a wake up call to all of us who are involved in risk assess­ment, remind­ing us to take ser­i­ously every risk we find, even those that seem neg­li­gible. Under­stand­ing our per­son­al biases, includ­ing those of our employ­ers. Dis­asters of the scope of Fukushi­ma are not unima­gin­able, but they can get lost in our blind-spots!

29-May update – A major tor­nado is now head­ing for Japan, and TEPCO has stated that the Fukushi­ma plant is not ready for the storm. They are con­cerned that more radi­ation will be spread by the storm.

Learn more about what happened at the plant:

TEPCO releases undis­closed data on nuc­le­ar crisis

Fukushi­ma nuc­le­ar power plant update: get all the data

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