The Nuclear Regulation Authority is planning a major slash in the budget for a forecasting tool for the spread of radioactive substances that was at the center of a controversy during the 2011 Fukushima nuclear accident.
The Nuclear Regulation Authority is planning a major slash in the budget for a forecasting tool for the spread of radioactive substances that was at the center of a controversy during the 2011 Fukushima nuclear accident.
The System for Prediction of Environmental Emergency Dose Information (SPEEDI) was designed to help government officials decide early on whether local residents should be evacuated.
However, a lack of information from the Fukushima No. 1 nuclear power plant made it difficult for the SPEEDI to operate as intended. Moreover, high-ranking government officials at the time, including Prime Minister Naoto Kan and Chief Cabinet Secretary Yukio Edano, were not informed of the existence of the system in the initial stages of the nuclear accident.
With some experts also raising doubts over whether it would be possible to improve the forecasting accuracy of the SPEEDI, the NRA had already downgraded data coming from the system to only "reference material" when it revised in 2013 its guidelines for dealing with nuclear accidents.
For the next fiscal year budget, the NRA will request less than half of what has been budgeted for the SPEEDI this year. About 500 million yen ($4.8 million) has been set aside for maintenance and management of the radioactive contamination forecasting system.
The NRA plans to divert the money that had been going to the SPEEDI for measures that would involve actual measurement of radiation levels.
One such measure is the installation of more monitoring posts in local communities near nuclear plants. Greater emphasis will be placed on actual measurement of radiation levels in deciding if residents should be evacuated in the event of a nuclear accident.
The revised guidelines call for making an evacuation decision for residents living within a 30-kilometer radius of a nuclear plant based on actual measurements from monitoring posts in the area.
In the event of a serious accident that could lead to the emission of large amounts of radioactive materials, residents within a 5-km radius will be ordered to evacuate immediately.
Those living within a radius between 5 kilometers and 30 kilometers will be asked to remain indoors before a decision is made on evacuation based on the actual radiation measurements.
The thinking behind the new guidelines is that quicker and more appropriate decisions can be made based on actual measurements rather than depending on forecasts that may not be totally accurate.
In line with those guidelines, the NRA has begun installing a system for sharing of radiation data among central and local governments. Officials involved in making evacuation decisions will be able to access data on their computer screens as the measurements are being made.
The money that had been going to the SPEEDI will also instead be used to improve the central government's monitoring of the new information-sharing system as well as for its maintenance.
Local governments are being asked to install monitoring posts in areas that could become subject to evacuation. The recommendation has been made to install monitoring posts at intervals of five kilometers depending on whether the area is residential or hilly and also on past spreading of radioactive materials.
Local governments had used the SPEEDI to put together their evacuation plans, and some officials are calling for maintaining the forecasting system.
With the shift toward a new system based on actual measurements, local government officials will now be faced with deciding how to utilize that information and how to transmit it to local residents in the event of a serious nuclear accident.