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Demonstration of the process control technology of contaminated water

R&D efforts (Application development linked to plant applications and actual use)

Completed projects (being operated by TEPCO)

Large-scale verification of impermeable walls (Ice Wall) (Countermeasures to Manage Contaminated Water) (FY 2014)
Summary

  Establishing technology to prevent groundwater from flowing into buildings within the Fukushima Daiichi NPS by surrounding them with large-scale impermeable walls (Ice Wall).

Action items
  1. Establish forming technology for impermeable walls (Ice Wall)
  2. Establish technology to control groundwater level
  3. Establish technology to operate impermeable walls (Ice Wall) over long periods
Implementing organizations

Implemented by Kajima Corporation and TEPCO.

Results & performance by fiscal year
  • FY 2014
High-performance Advanced Liquid Processing System (High-performance ALPS) equipment verification (Countermeasures to Manage Contaminated Water) (FY 2014)
Summary

Conducting equipment verification for High-performance ALPS to further reduce waste by 80% over the current Advanced Liquid Processing System (ALPS: reduces 62 nuclides in contaminated water below notification concentrations) that removes radiation materials from contaminated water within tanks.

Action items
  1. Laboratory tests to verify the removal function
  2. Verification of removal function using test equipment that is very similar to the actual equipment, etc.
  3. Check removal function using improved ALPS
Implementing organizations

Implemented by TEPCO, Toshiba Corporation, Hitachi-GE Nuclear Energy, Ltd.

Results & performance by fiscal year
  • FY 2014

Completed projects

Verification tests for tritium separation technology (Project of Decommissioning and Contaminated Water Management)
Summary

While efforts are being made to remove 62 nuclides from contaminated water that is generated within Fukushima Daiichi NPS, tritium cannot be separated out and remains, so they conducted tests related to tritium separation technology. In practical terms, in order to test separation of tritiated water generated at Fukushima Daiichi NPS, they conducted verification tests using arbitrarily-sized equipment that allowed them to evaluate separation performance, construction costs and running costs.

Action items
  1. Build implementation-scale equipment for verification tests
  2. Verify separation functions using the respective equipment
  3. Evaluate construction cost, running cost, site area, and equipment height
Implementing organization

The following 7 parties each used their separation equipment to implement separately:

  • Kurion, Inc.
    :Combined Electrolysis Catalytic Exchange (CECE)
  • Federal State Unitary Enterprise “Radioactive Waste Management Enterprise “RosRAO”
    :Combination of Combined Electrolysis Catalytic Exchange (CECE) and Water Distillation
  • Sasakura Engineering Co., Ltd.
    : Low temperature vacuum distillation method with catalytic function
  • Hokkaido University, National University Corporation
    : Electrolysis recombination method using fuel cells
  • Nextide, Inc.
    : Multiple electrolytic cell electrolytic method
  • Toshiba Corporation
    : Multistage crystallization method
  • So Innovation Inc.
    : 2-stage gas hydrate method
Results & performance by fiscal year
  • FY 2015
  • Final report
  • Applicability
  • FY 2014
  • Interim report
Seawater purification technology verification (Project of Decommissioning and Contaminated Water Management)
Summary

While concentrations of radioactive materials remained low outside the harbor and at the harbor mouth at the Fukushima Daiichi NPS in April 2014, because concentrations in one area within the harbor in front of the inlet channels of Units 1 to 4 did not go below a specified concentration, they conducted tests to verify removal performance of purification technology, mainly for radioactive cesium and radiostrontium, etc. within sea water.

Action items

Tested the technical feasibility and appropriateness of the following items:

  • Purification system basic concept
  • Objective removal performance
  • Maintenance concepts
  • Secondary waste concept
  • Removal efficiency
  • Sustainability of removal performance
  • Preventing generation of secondary waste
Implementing organizations

The following 5 parties each used their technologies to implement separately:

  • Mitsubishi Heavy Industries, Ltd.
    : Tested removal performance of a purification system that combines processing equipment before removal of pollutants from seawater and their own collection system adapted to use in seawater.
  • IBC Advanced Technologies, Inc.
    : Tested removal performance of a purification system that operates underwater, using their own adsorbent material that has had results collecting radionuclides.
  • Obayashi Corporation
    : Developed a highly adsorbent collection material for both cesium and strontium, utilizing natural materials, and tested its removal performance, durability against radiation, and secondary waste amount.
  • Atox & Areva NC Ltd., and Areva Atox D&D Solution Ltd.
    : Developed a new combustible adsorption sheet, and tested the removal performance and secondary waste amount on an underwater purification system which employed the material.
  • JGC Corporation
    : Considering the differences in chemical characteristics between cesium and strontium, they developed a new fibrous adsorption material, and tested the removal performance of cesium and strontium from seawater, and secondary waste amounts.
Results & performance by fiscal year
  • FY 2014
  • Final report
  • Interim report
  • Applicability
Verification of collection technology for radioactive material in soil (Project of Decommissioning and Contaminated Water Management)
Summary

Because of cases of leakage of contaminated water at Fukushima Daiichi NPS, they conducted tests to verify collection performance of collection technology for radioactive materials in soil (primarily radiostrontium) under chloride ion concentrations above a specified level (200ppm and higher).

Action items

Tested the technical feasibility and appropriateness of the following items:

  • Collection efficiency for radioactive materials
  • Concept for soil environment at installation site
  • Maintenance concept
  • Secondary waste concept
  • Collection efficiency
  • Sustainability of collection efficacy
  • Prevention of generation of secondary waste
Implementing organizations

The following 2 parties each used their technologies to implement separately:

  • Atox & Areva NC Ltd., and Areva Atox D&D Solution Ltd.
    : Tested the collection performance of permeation-type reactive barrier technology for radiostrontium in soil.
  • JGC Corporation
    : Utilizing a fibrous adsorption material that has high capacity for collecting strontium, they tested the structure and construction process of a permeable wall that can efficiently collect and recover strontium in groundwater.
Results & performance by fiscal year

Posted in results and demonstrations for each fiscal year for “Seawater purification technology verification”

Verification of decontamination technology for contaminated water storage tanks (Project of Decommissioning and Contaminated Water Management)
Summary

Bolted tanks have been replaced by welded tanks sequentially within the Fukushima Daiichi NPS site. However, bolted tanks have a complicated structure, so they drained contaminated water within the bolted tanks and performed verification test on decontamination performance on decontamination work to be performed prior to dismantling the tanks, in order to reduce the exposure of workers that dismantle the tanks.

Action items

Tested the technical feasibility and appropriateness of the following items:

  • Decontamination performance
  • Waste concept
  • Handling inner curved surfaces of tanks and joints
  • Handling tanks on the inner side of a group of tanks
  • Preventing generation of waste, etc.
Implementing organizations

The following 3 parties each used their technologies to implement separately:

  • IHI Corporation
    :Tested removal performance and waste recovery performance applying ultra-high pressure liquid nitrogen technology for decontamination of tanks with complicated shapes.
  • Obayashi Corporation
    :Tested decontamination performance of remote decontamination equipment that used the optimal combination of 3 decontamination technologies of dry-ice blasting, machine cutting, and shot blasting.
  • Kobe Steel, Ltd.
    :Tested the performance of a decontamination system for the interiors of tanks, that re-uses residual contaminated water from the bottoms of tanks as purification water, in order not to increase contaminated water.
Results & performance by fiscal year

Posted in results and demonstrations for each fiscal year for “Seawater purification technology verification”

Tested unmanned boring technology (Project of Decommissioning and Contaminated Water Management)
Summary

Boring construction work will be essential at Fukushima Daiichi NPS in the future, and they conducted tests of unmanned boring performance under high dose rates in order to reduce exposure of workers during boring construction work.

Action items

Tested the technical feasibility and appropriateness of the following items:

  • Applicable sites for unmanned boring technology
  • Boring performance concept
  • Reducing work time
  • Work space
  • High quality boring
Implementing organization

The following 1 party implemented this.

  • Obayashi Corporation
    : Developed a remotely operated boring system using satellite communications for three phases of the boring process, including 1) the initial drilling, 2) coring drilling, and 3), reaming, and conducted verification tests for the system’s feasibility and applicability.
Results & performance by fiscal year

Posted in results and demonstrations for each fiscal year for “Seawater purification technology verification”

R&D efforts (Related basic and generic research)

<Updated regularly>

Plant investigation, measurement data, and information

Contaminated water related data
Current Status of Fukushima Daiichi NPS 
Results of water quality analysis  
  • Overall
  • Building periphery (sub-drains, etc.)
  • Groundwater bypass
  • Harbor & ocean
Stagnant water status  
Tank status  

Other related information

Overview of contaminated water countermeasures
Studies by the Committee on Management of Contaminated Water
Contaminated water countermeasure efforts at Fukushima Daiichi NPS by the Atomic Energy Society of Japan