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Evacuation plan for east Japan nuclear plant was focused on inaccurate, simplified data

Tokai No. 2 nuclear power plant, right, operated by Japan Atomic Power Co., is seen here from a Mainichi Shimbun helicopter in March 2021. (Mainichi)

TOKYO -- Officials from east Japan's Ibaraki Prefecture, which hosts the Tokai No. 2 nuclear power station in the village of Tokai, insisted that nearby prefectures not exclude uninhabitable spaces including bathrooms, lobbies and storage rooms at gymnasiums serving as evacuation centers when calculating their evacuee capacity as part of the power plant's overall evacuation plan, according to the minutes of a meeting obtained by the Mainichi Shimbun.

    Officials in nearby prefectures questioned the validity of the Ibaraki Prefectural Government's instructions on methods to "secure" 2-square-meter per evacuee in a simple by-the-numbers calculation style. The Ibaraki government, however, pushed through with its policy.

    In the Tokai No. 2 power plant's broad evacuation plan, local governments would take in some 940,000 residents living within a 30-kilometer radius of the nuclear plant. But the Mainichi Shimbun has learned that evacuation centers in 15 Ibaraki Prefecture municipalities were found to have overcalculated their maximum capacities, and currently over 20,000 people's worth of space at evacuation centers is lacking. Furthermore, it has emerged that municipalities in four nearby prefectures -- Tochigi, Chiba, Gunma and Saitama -- also have evacuation centers where maximum capacity has been overestimated. The clear source of the problem is disregard for effective planning.

    The meeting took place on Sept. 26, 2014 at the Secretariat of the Nuclear Regulation Authority, and was the second session of the Tokai No. 2 nuclear power station's working team. In response to changes following the incident at the Fukushima Daiichi nuclear power plant that expanded the metric for residents subject to evacuation plans to anyone living within 30 kilometers of a nuclear power plant, the head of Ibaraki Prefecture's nuclear safety measures section, the disaster prevention officials from five nearby prefectures (Fukushima, Tochigi, Chiba, Gunma and Saitama), and officials from the Cabinet Office attended the meeting. The Mainichi Shimbun obtained its minutes through a freedom of information request.

    According to the minutes, an Ibaraki Prefectural Government official said at the beginning of the meeting that evacuation centers' capacity in the prefecture was calculated based on providing 2 square meters per person, and that they were split amongst the various villages, towns and cities where people would be evacuating. Because the maximum limit of people who can be evacuated within the prefecture is 443,000, Ibaraki Prefecture requested that the remaining 517,000 of the then population of 960,000 people living within 30 kilometers of the Tokai No. 2 plant be received as evacuees by the nearby five prefectures.

    Moreover, the Ibaraki prefectural official distributed the survey form used in Ibaraki as a template to the other prefectures, and requested that they add up the area of evacuation centers and simply divide that figure by two, by asking the municipalities in their respective prefectures the areas of gymnasiums and other facilities that could be used as evacuation centers.

    After the Ibaraki prefectural official's presentation ended, a question-and-answer session began. When a Cabinet Office official urged attendees to speak up, a representative for Gunma Prefecture asked, "Taking the area (of an evacuation center) and simply dividing that by two, and the number of people that can actually be held in an evacuation center are two different things. Which are we supposed to calculate?" The Ibaraki prefectural official said, "At this moment, we are thinking about getting the maximum number that can be simply calculated."

    An official from Saitama Prefecture asked, "What do we do if a (simply calculated) number of evacuees that can be held in a facility is 1,000, but the schoolyard is too small and parking spots for only 50 people can be secured?" In response, the Ibaraki Prefecture official and the Cabinet Office personnel said they would "deliberate the issue of parking spaces in the future," and stressed that for the time being, each prefecture should work out the area of their evacuation facilities and calculate the maximum number of evacuees they can accept based on those numbers.

    Furthermore, the prefectures present at the meeting sought a survey form simpler than the one Ibaraki Prefecture distributed, citing its excessively intricate format, which would be too much to handle with the limited workforce available to municipal governments. Perhaps in response to these remarks, the survey forms later used in four of the prefectures, excluding Fukushima, were arranged so that if a facility's area is entered into calculation software, it automatically divides the number by two to work out how many people could evacuate there.

    At the end of the meeting, the head of Ibaraki Prefecture's nuclear safety measures section said that they wanted to formulate Ibaraki Prefecture's evacuation plan before the end of that fiscal year in March 2015, and asked that the other prefectures do their surveys swiftly even if it might mean extra work under tight schedules. Indeed, in March of 2015, the Ibaraki Prefectural Government drew up a general outline for an evacuation plan for municipalities within 30 kilometers from the Tokai No. 2 nuclear power plant.

    The then head of the Ibaraki Prefecture nuclear safety measures section told the Mainichi, "We had this vision of first getting a broad picture of what sort of capacity for evacuees each prefecture had, and then carrying out discussions later to sort through the finer points. Aside from Fukushima Prefecture, the other prefectures do not host any nuclear power plants and seemed to be at a loss as to what to do, so we felt we couldn't make bold requests to them from the start."

    Hirotada Hirose, an expert in nuclear plant evacuation plans and a professor emeritus in disaster risk studies at Tokyo Woman's Christian University, said, "It is evident that calculations were being made with knowledge that the numbers would be inaccurate and inflated." He added, "Unless evacuation plans are formulated, nuclear power plants cannot be reactivated. (The Ibaraki Prefectural Government) appears to think that as long as they put up a front (of being careful) to a certain extent, that would be enough, out of consideration for the Japanese government's desire to go ahead with resuming the nuclear plant's operations. Evacuation plans are made in the event a disaster occurs, but this plan presupposes that no disaster will occur."

    (Japanese original by Kosuke Hino, Digital News Center)

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