SPEEDI should have been used to plan evacuations

July 16, 2012

Govt. panel: SPEEDI use may have avoided exposure

http://www3.nhk.or.jp/daily/english/20120716_02.html

A government panel investigating the Fukushima Daiichi nuclear power plant accident will issue its final report next week.

It will say residents could have avoided unnecessary exposure to radiation if the government's system for predicting the spread of radioactive substances had been used to plan their evacuations.

The government activated the SPEEDI system using unconfirmed data from the day the accident occurred because it failed to obtain information on where radioactive materials originated. But officials did not publicize the results.

The panel is studying the Science Ministry's SPEEDI results and the evacuations of residents. It plans to issue its final report on July 23rd.

The report will say SPEEDI predicted in the afternoon of March 15th last year that radioactive elements would spread inland toward the west and northwest. Residents were fleeing in those directions on that day.

SPEEDI also forecast that from the dawn of March 16th a change in wind directions would send radioactive substances out over the Pacific Ocean.

The report will say people could have avoided unnecessary exposure to radiation if the government had used SPEEDI predictions in planning evacuations and if residents had been ordered to stay inside on March 15th and seek refuge on the following day.

Discussions will be held to determine how SPEEDI forecasts can be used in planning future evacuations.

Earlier this month, another panel of experts commissioned by the Diet issued its report which included a different conclusion on SPEEDI from that of the government committee.

It said SPEEDI forecasts cannot be used as a basis to craft initial evacuation plans due to the limited accuracy of weather information to be used in predictions.