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information about Fukushima published in English in Japanese media info publiée en anglais dans la presse japonaise

30-km radius not safe enough

 June 18, 2014


EDITORIAL: Abe needs to get priorities right before reactor restarts



The central government has required all prefectural and municipal entities within a 30-kilometer radius of nuclear power plants to have their own emergency response plans.

This was one of the lessons of the 2011 Fukushima nuclear disaster.

Does it follow then that areas outside the 30-km radius are safe?

That is anything but the case, as indicated by estimates of predicted dispersions of radioactive materials made by local governments around nuclear power plants.

For example, the border of Hyogo Prefecture is at least 40 kilometers from the offline Oi and Takahama nuclear power plants in Fukui Prefecture, which operator Kansai Electric Power Co. intends to restart at an early date.

But the Hyogo prefectural government used data on past weather patterns to estimate what levels of radiation thyroid glands would be exposed to in the event of Fukushima-class disasters taking place at both the Oi and Takahama plants. It found that the doses could exceed the international benchmark of 50 millisieverts in seven days, even on Awajishima island, which is 150 kilometers from the nuclear power plants. Individuals exposed to radiation levels of 50 millisieverts or higher are advised to take iodine tablets to protect their thyroid glands from radiation.

Depending on wind direction, similar scenarios were also indicated for the cities of Kobe, Amagasaki, Nishinomiya and elsewhere along the Hanshin belt between Osaka and Kobe.

Simulations by the Shiga prefectural government found that, in a worst-case scenario, a Fukushima-class disaster at Oi could spread radioactive materials exceeding the international benchmark into the airspace above Lake Biwako, more than 40 kilometers away. Similarly affected areas could include parts of Kyoto and Osaka prefectures.

What do these estimates signify?


A major accident at a nuclear power plant releases radioactive substances, which will eventually contaminate surface areas. Under international standards, evacuations and decontamination work would be required in areas where an individual's total body irradiation level exceeds 100 millisieverts in seven days. In the event of a Fukushima-class disaster, the areas requiring evacuation and decontamination work would be roughly within a 30-km radius of the stricken plant.

But winds carry and spread airborne radioactive plumes further away. In areas where radioactive iodine in the atmosphere has not been sufficiently rarefied, thyroid glands are exposed to radiation and the risk of thyroid cancer rises, especially among small children. It is vital to put a system in place to speedily discern the spread of radioactive plumes and determine the right timing for people to take iodine tablets.

One other factor that must be taken into consideration is that when it rains along the plume's track, concentrations of cesium and other radioactive materials that have long-term effects will fall to the ground and contaminate the soil. When that happens, temporary measures will not be sufficient.

In the Fukushima Prefecture village of Iitate, about 40 km from the crippled Fukushima No. 1 nuclear power plant, rain fell just when a radioactive plume reached the community. Before the nuclear disaster, the villagers were in the process of building a self-sustaining farming operation in the belief that everyone could live happily. The village had not benefited financially from the nearby nuclear power plant. But since the disaster, the entire village has remained off-limits to the villagers.

The Union of Kansai Governments, whose members come from seven prefectures, including Osaka and Kyoto, has called on the central government to issue comprehensive guidelines on measures that should be taken in areas outside the 30-km radius from nuclear power plants, based on studies by local governments.

Viable evacuation plans, along with prepared guidelines, need to be in place before issuing the order to evacuate. Otherwise, chaos can result. This was made clear from statements given to the government’s Investigation Committee on the Accident at the Fukushima Nuclear Power Stations by Tetsuro Fukuyama, a former deputy chief Cabinet secretary who was in charge of the evacuation process during the Fukushima crisis.

Acknowledging the need for such guidelines, the central government states in its nuclear disaster response policy outline that the Nuclear Regulation Authority will consider defining the extent of evacuation zones and other matters. However, the NRA has yet to embark on this task in earnest, mainly because it is engaged in safety screenings ahead of nuclear power plant restarts.


With nuclear power generation, there is no such thing as "absolute safety"--no matter how stringent the regulations. If any nuclear power plant is to be put into operation, the very least that must be done is to get an accurate grasp of the areas that will be affected in the event of a disaster.

By the same token, residents of those areas need to be informed of the exact nature of the risks they face and the steps that will be taken in the event of a nuclear accident.

But to assume the central government understands this concept would be asking a lot. Even though municipalities that host nuclear power plants will not be the only ones affected in a nuclear accident, the government's Strategic Energy Plan states that the central government "will strive to obtain the understanding and cooperation of people associated with the municipalities that host nuclear power plants" before restarting offline reactors. Here, we can see right through the government's intent to press for the resumption of operations by taking advantage of those local governments' dependence on nuclear power plants for their fiscal and employment needs.

After the onset of the Fukushima disaster, Shiga Governor Yukiko Kada came up with the term "higai jimoto" to denote all local governments, not just those which host nuclear power plants, that could be seriously affected by a nuclear accident. Kada demanded the central government recognize them all as affected parties and allow them to get involved in the process before restarting nuclear plants. This is a legitimate demand. In reality, however, it is still only the municipal and prefectural governments hosting nuclear power plants that have any real say.

Toshiki Kudo, mayor of Hakodate in Hokkaido, who filed a lawsuit demanding the suspension of construction of the Oma nuclear power plant in neighboring Aomori Prefecture, warned that the same old "safety myth" of nuclear power generation will be perpetuated if the project is allowed to have its way.

"It will be game over for our country if the government stops trying its hardest to win the understanding of the people," Kudo said.

At a recent news conference on Japan's right to collective self-defense, Prime Minister Shinzo Abe reiterated that the government will "protect lives of the Japanese people." If he is genuinely committed to saving people's lives, he obviously needs to look squarely at all local communities that could be seriously affected by a nuclear disaster before he can even begin to argue in favor of restarting idle nuclear reactors.

--The Asahi Shimbun, June 18



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