On July 28, 2017, the Japanese government released a geoscientific characteristics map to provide a basis for selecting locations for high-level nuclear-waste disposal sites. The map, on a 1:2,000,000 scale, shows the entire Japanese archipelago, accompanied by five aerial maps. The explanations of the standpoints used to evaluate aerial favorability for site construction are provided, along with the criteria for those standpoints, accompanied by the maps, which use color-coding to indicate individual standpoints.
The map divides the nation into four colors. The areas unfavorable from the standpoint of the stability of deep underground strata are colored in orange; the areas unfavorable because of the possibility of excavation for mineral resources in silver; the areas having favorable characteristics in pale green; and the areas that are additionally favorable in terms of transportation convenience in dark green (these areas are called green coastal areas).
In Japan, an act concerning the deep geological disposal of high-level nuclear wastes was established in 2000. It stipulates the methods of selecting disposal sites based on a stepwise approach, and the Nuclear Waste Management Organization (NUMO) was established as the organization that is taking the initiative in selecting the sites and carrying out the disposal process. The stepwise approach consists of three steps; a literature survey, a general survey, and a detailed survey. NUMO, established mainly by electric power companies, encouraged municipalities across the nation (about 3,500 in total at that time) to apply for a literature survey.
However, all the municipalities that showed an interest in application later abandoned the idea due to strong protest. In 2007, Toyo Town, Kochi Prefecture, which was the only municipality that managed to submit an application, was obliged to withdraw it because of strong protest that demanded the recall of the town mayor. After this event, the government judged that the site selection process would not go forward if it continued to wait passively for applications, and thus adopted a second approach for use in parallel to the passive approach ‒ it decided to look for municipalities and encourage them to apply for a literature survey.
Thereafter the government used every opportunity to exchange opinions with many municipalities, and in spring 2011, it was prepared to request about 10 municipalities which had showed an interest to accept a literature survey. However, the Fukushima Daiichi NPS accident occurred immediately before the delivery of the request. The government became unable to pursue this plan any further, and the entire attempt to encourage municipalities to apply collapsed.
The municipalities' interest had been attracted by government money, which were to be paid in return for their acceptance of the survey. After the Fukushima Daiichi accident, public criticism against nuclear power increased. Under such conditions, the government realized that gaining municipalities' interest would not be sufficient and that it would be necessary to show scientific reasons to justify the survey. In 2013, the government devised another approach, which was firstly to show the geoscientific characteristics of individual areas, secondly to identify the areas that could possibly host a disposal site, and thirdly to encourage municipalities that might be interested to accept a literature survey. It was the first time the government had adopted such an attempt.
The geoscientific characteristics map was created in this context. The map color codes indicate the areas judged unfavorable from a set of standpoints ‒ volcanic activity, fault activity, upheaval, denudation, geothermal activity, bedrock hardness, the ranges influenced by pyroclastic flows, and prospective mineral resources. The areas judged favorable in terms of transportation (about 20 km from the shore) are also color-coded. Based on these standpoints, the archipelago is color-coded in four colors. The geological conditions specific to each area will be examined in the literature survey, with reference to geological records, while the characteristics map shows the divisions based only on the information available nationwide.
Therefore, while the map is called a geoscientific characteristics map, the characteristics specific to individual areas are not always reflected. As an example, the map is supposed to exclude areas having pyroclastic flow deposits younger than 10,000 years as not favorable, but the map does not consider the range of influence of the pyroclastic flow from a possible eruption of the Kikai Caldera Volcano, Kagoshima Prefecture, the most recent eruption of which was 7,300 years ago. This influence will be considered in the literature survey. Many areas in Tokyo are classified in the green coastal areas, but because the Kanto Plain was formed during the Quaternary period, the bedrock is still soft deep underground, and there may be many unlithified rocks. This should also be considered in the literature survey.
This geoscientific characteristics map does not consider restraints in the use of land due to legislation or international treaties, nor social conditions such as population density and the number of landowners.
NUMO's conventional conditions for the acceptance of survey applications were only volcanic activity and fault activity. The other standpoints are included in the social characteristics map scheduled to be examined in the literature survey. Therefore, the release of the map is a step forward for the government. NUMO is modifying the acceptance conditions in order to be consistent with the conditions described in the map.
The Japanese archipelago lies in the tectonic movement zone, where four plates meet. Even if all the conditions presented in the map are satisfied, it would still be difficult to isolate wastes from the environment for more than 100,000 years. Especially, information on relatively large amounts of deep underground water, which should essentially be considered for long-term stability, is limited. The government intends to ensure the long-term safety of high-level waste (HLW) by using engineering methods, and this governmental intention remains unchanged.
After the release of the geoscientific characteristics map, the government and NUMO intend to promote activities to gain public understanding, mainly in the areas whose characteristics have been judged favorable (green coastal areas). However, of the 47 prefectures nationwide, 20 prefectures have already turned down the survey. Citizens' movements against nuclear power generation have been powerful since the Fukushima Daiichi accident, and the movement strongly demands that all nuclear power plants be shut down first in order to halt the accumulation of HLW. The Science Council of Japan also stated that the upper limit of HLW should be determined (2012). However, the government and NUMO intend to promote the conventional concept and plan of geological waste disposal, separating the disposal site issue from the controversy of nuclear power plants. This head-on disagreement is expected to continue.
The government does not make efforts to form a participatory consensus concerning the treatment of HLW. As an example, consensus meetings or deliberative polls have not been conducted and are not planned. The government councils did not discuss ways in which to obtain social agreement. What the government has attempted to do thus far is to try to earn public agreement for its geological disposal policy. However, what it has actually been engaged in is organizing gatherings that attempt to obtain public agreement for the government's plan, under the name of explanatory hearings.
The government's stance concerning the new characteristics map is that its release is not intended to persuade municipalities to accept a survey for disposal site selection; the government says that it will not initiate any survey unilaterally without gaining the agreement of the locals. According to the government, "this is the first step in a long road to realize final HLW disposal."
NUMO plans to begin the first step by organizing dialogue gatherings with a small number of people in the areas judged favorable from all the standpoints including transportation. NUMO said that it would release the schedule of dialogue gatherings, but to date, it has not been released. It is not known when the schedule will be announced, but from October this year, the government and NUMO plan to hold explanatory hearings about the geoscientific characteristics map in 45 prefectures. With publicly invited participants, the gatherings will be used by the government to explain the map during the first half of the hearings, and during the second half the participants will be divided into small groups to exchange opinions with NUMO. Through this group dialogue, NUMO expects to exploit human resources who can work proactively to invite the site to the area.
While the geoscientific characteristics map has been made public, when literature surveys will begin is unknown, and the issue of disposal site selection is expected to confront many problems.
Reprinted from Nuke Info Tokyo No. 180, Sept/Oct 2017, www.cnic.jp/english/?p=3956