TEPCO's Fukushima Daiichi Timeline - INPO

A report prepared by the North American Nuclear Industry peer group (INPO - Institute of Nuclear Power Operators) has issued a comprehensive report of the initial hours and days following the March 11 earthquake and tsunami in Japan. A detailed and agreed timeline was an important prerequisite to developing many significant lessons learned from the 1979 Three Mile Island Unit 2 accident in Pennsylvania, USA. Many of these lessons (symptom-based vs event-based emergency planning, re-mapped alarm panels and significant revisions to operator actions and training) developed as a specific result of the TMI-2 investigation are now standard practice in nuclear energy programmes worldwide.

In this earlier post below, I cautioned about the risks of early information, mostly because the best source of that information - TEPCO - had to direct their information and communication mechanisms to event management, transient response and accident mitigation; including addressing the immediate needs of their employees and members of the local public most affected by the accidents. At the time these were the only priority. Responsibility for communicating with the broader world - who had legitimate concerns - fell to support organisations and/or government ministries. They did their best with what details they could obtain. But it would be a stretch to call that information anything beyond preliminary and highly suspect to review and revision.

The INPO report may be downloaded here.

There's a good New York Times report on it here.

"The chronology does not draw any conclusions about the accident, or analyze the actions taken after the earthquake. It is intended, instead, to provide an agreed-upon set of facts that American companies, the Nuclear Regulatory Commission and others can use in identifying lessons from the disaster for the American industry."

"The report also takes note of the human toll of the disaster among the workers, though the prose is more industrial than dramatic.

It points out that many plant workers had lost their homes and even their families in the tsunami, and that for days after the quake, they were sleeping on the floor at the plant, and soaking up radiation doses even in the control room. Because of food shortages, they were provided with only a biscuit for breakfast and a bowl of noodles for dinner.

Working in darkness and without electricity, even simple tasks became challenging. At one point, control room operators formed themselves into teams of two, to dash into high-dose areas to try to open a crucial vent. One would hold the flashlight, monitor radiation dose and perform other support tasks, and the other would try to get a valve to move. But there was no communication once the team was in the field, so the next team could leave only after the first had returned."

Their bravery and commitment to duty are to be commended. Had it not been for the TEPCO operators and engineers at Daiichi and other sites such as Daini, the results would likely have been considerably worse.