Monday, January 9, 2017

Radioactive Waste in Japan Proposed as Construction Material

Japan faces unprecedented volumes of radioactive nuclear waste produced by the Fukushima disaster with no storage solution. The waste is often stored in plastic bags that are piled up high, as illustrated in the photo that accompanies this news story from the Mainichi about the Environment Minister's plan to use radioactive waste in construction projects:
Nuclear watchdog questions Environment Ministry's plan to reuse radioactive soil. The Mainichi, January 9, 2017 (Mainichi Japan)

The Nuclear Regulation Authority (NRA) has raised questions about the Environment Ministry's proposal to reuse radioactive soil resulting from decontamination work around the crippled Fukushima No. 1 Nuclear Power Plant due to the insufficiency of information on how such material would be managed, it has been learned.

As the ministry has not provided a sufficient amount of information, the nuclear watchdog has not allowed the ministry to seek advice from its Radiation Council -- a necessary step in determining standards for radiation exposure associated with the reuse of contaminated materials.

The Ministry of the Environment discussed the reuse of contaminated soil in closed-door meetings with radiation experts between January and May last year. The standard for the reuse of such materials as metal produced in the process of decommissioning nuclear reactors is set at 100 becquerels of radioactive cesium per kilogram. Materials with a contamination level topping 8,000 becquerels are handled as "designated waste" requiring special treatment. In examining the reuse of contaminated soil, the ministry in June decided on a policy of reusing soil containing up to 8,000 becquerels of radioactive cesium per kilogram as a base for roads with concrete coverings.
Essentially, it appears from this article that the Ministry of Environment is promoting "recycling" of waste containing up to 8,000 becquerels of radioactive cesium per kilogram in road construction but that Japan's Nuclear Regulatory Association (NRA) has concerns about the plan, as well it should.

Radioactive cesium (134, 137) is treated as bio-identical with stable potassium by our bodies and therefore bioaccumulates in muscle, including the heart.

Radioactive cesium used in road construction and other projects will no doubt leach into the surrounding environment and be absorbed by plants and animals, as well as ending up in the water supply.

Japan's fresh water supplies used for agriculture and drinking are already facing cesium contamination. This plan to use radioactive waste in construction project is likely to worsen this problem:
Health risk or not? Cesium levels high in hundreds of Fukushima reservoirs. SHINICHI FUJIWARA February 25, 2014

[excerpted] A joint survey by the prefectural government and a branch office of the farm ministry found that the levels exceed 8,000 becquerels per kilogram of soil in 576 reservoirs. In 14 of those cases, the level tops 100,000 becquerels. The central government says that reservoirs, many of which are located in residential areas, are not covered by its decontamination program.  
The survey covered 1,939 reservoirs, or slightly more than half of the 3,730 in Fukushima Prefecture for agricultural use. Prefectural authorities, fearing that contaminated mud from the reservoirs may reach farmland and create a health hazard for residents, is asking the central government to remove the waste. Contaminated soil exceeding 8,000 becquerels corresponds to designated waste that must be removed at the central government's initiative. …. Of the 14 reservoirs where cesium contamination exceeds 100,000 becquerels, nine are located in evacuation order zones. The remaining five are situated outside those areas. The highest contamination level of 390,000 becquerels was detected in the Ominamisaku reservoir in the town of Futaba ... [end]
See this talk by Steven Starr for more background on the health risks of cesium:



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