85% of Special Decontamination Area remained contaminated Fukushima Daiichi decommissioning road map unachievable – a new plan is inevitable via Greenpeace Japan

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“Successive governments during the last ten years, and largely under prime minister Shinzo Abe, have attempted to perpetrate a myth about the nuclear disaster. They have sought to deceive the Japanese people by misrepresenting the effectiveness of the decontamination program and ignoring radiological risks,” said Shaun Burnie, Senior Nuclear Specialist at Greenpeace East Asia. 

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The key findings of the radiation report Fukushima 2011-2020 are:

  • Greenpeace has consistently found that most of the 840 square kilometers Special Decontamination Area(SDA), where the government is responsible for decontamination, remains contaminated with radioactive cesium. 
  • Analysis of the government’s own data shows that in the SDA an overall average of only 15% has been decontaminated.
  • No time frame for when the Japanese government’s long-term decontamination target level of 0.23 microsieverts per hour (μSv/h) will be achieved in many areas. Citizens will be subjected for decades of radiation exposure in excess of 1mSv/y recommended maximum.
  • In the areas where evacuation orders were lifted in 2017, specifically, Namie and Iitate, radiation levels remain above safe limits, potentially exposing the population to increased cancer risk. Plans to continue to lift evacuation orders are unacceptable from a public health perspective.
  • Up till 2018, tens of thousands of decontamination workers had been employed in decontamination in the SDA. As documented by Greenpeace[1], the workers, most of whom are poorly paid subcontractors, have been exposed to unjustified radiation risks for a limited and ineffective decontamination program. 

The key findings of The Fukushima Daiichi Nuclear Power Station decommissioningreport[2] are:

  • There are no credible plans for retrieval of the hundreds of tons of nuclear fuel debris remaining inside and under the three Reactor Pressure vessels – it requires a fundamental review. 
  • Water used in reactor cooling and groundwater contamination, and therefore accumulating in tanks, will keep growing into the future unless a new approach is adopted.
  • All nuclear contaminated material should remain on the site indefinitely. If the nuclear fuel debris is ever retrieved, it also should remain on site. Fukushima Daiichi is already and should remain a nuclear waste storage site for the long term. 
  • The current plan is unachievable in the timeframe of 30-40 years in the current road map and impossible to achieve in terms of returning the site to greenfield.

It is recommended that a fundamental rethink in approach and a new plan for the decommissioning of Fukushima Daiichi, including a delay in molten fuel removal for 50-100 years or longer is needed with the construction of secure containment buildings for the long term. The Primary Containment vessel, with reinforcement, should be used as an incomplete primary boundary and the reactor building as the secondary boundary for the medium-to-long term, while developing robotic technology that can perform tasks without high radiation risks to human workers. 

Finally, to prevent the further increase of radioactive contaminated water, cooling of nuclear fuel debris should be switched from water to air cooling, and the Fukushima Daiichi site should be made into a ‘dry island’ isolated from groundwater with the construction of a deep moat. 

ENDS

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