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Device/equipment development/demonstration for the full scale practical system research and measurement

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

Ongoing projects

Development of Investigation Technology of Inside of RPV (Project of Decommissioning and Contaminated Water Management)
Summary

In order to contribute to consideration concerning fuel debris retrieval inside of the Reactor Pressure Vessel (RPV), the investigation technology for grasping the situation of fuel debris inside RPV etc. shall be developed.

Action items
  1. Development of Access-from-Bottom Investigation Method
  2. Upgrading of processing technology in the Access-from-Top Investigation Method
  3. Development of Investigation Technology of Inside of RPV by using Existing Pipes
Implementation plan

Targeted process: Development of investigation technology of inside of RPV

Source: FY 2023 Research and Development Plan for Decommissioning
    (METI, Secretariat of the Team for Countermeasures for Decommissioning and Contaminated Water Treatment (February 22, 2023 ))
(PDF page 4)

Results & performance by fiscal year
  • FY 2022
  • FY 2021
  • FY 2020
  • FY 2019
  • FY 2018
  • FY 2017
  • FY 2016
  • FY 2015
  • FY 2014
Results & performance for individual projects, etc. (Archives)

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Completed projects

Development of Technologies for In-depth Investigation of PCV Inside (Project of Decommissioning and Contaminated Water Management)
Summary

In order to investigate the distribution of fuel debris in the Reactor Primary Containment Vessel (PCV) and the situation inside and outside the pedestal with higher accuracy than before, we will develop and demonstrate equipment and more advanced investigation technology.

Action items
  1. Development of detailed investigation technology inside the pedestal from the CRD opening of the pedestal
    (1) Formulation / update of detailed investigation plan / development plan inside pedestal
    (2) Development of access / investigation equipment and investigation technology for detailed investigation inside the pedestal
Implementing organizations

Implemented by IRID.

Implementation plan

Targeted process:Development of technologies for in-depth investigation of PCV inside

Source: FY 2022 Research and Development Plan for Decommissoning
    (METI, Secretariat of the Team for Countermeasures for Decommissioning and Contaminated Water Treatment (January 27, 2022))
(PDF page 9)

Results & performance by fiscal year
  • FY 2022
  • FY 2021
  • FY 2020
  • FY 2019
  • FY 2018
  • FY 2017
Predecessor project: Development of Investigation Technology of Inside of PCV (Project of Decommissioning and Contaminated Water Management)
Summary

We developed inspection equipment and systems using remote operations to verify the condition inside of the pedestal inside the PCV and performed plant verification, to contribute to retrieval of fuel debris. Also we made the development plan in order to carry out the more in-depth actual unit inspection for fuel debris retrieval, and performed the elemental test.

Action items
  1. Make and revising inspection/development plans
  2. Development of access/inspection device and system to specific areas
    (1) Inspection inside the pedestal of Unit 2
    • A2' Inspection: visual inspection of platform bottom
    (2) Inspection inside the pedestal of Unit 3
    • Visual inspection technology by underwater swimming device
  1. On-site inspection (on-site validation)
Implementing organizations

Implemented by IRID.

Implementation plan

Targeted process:Development of investigation technology of inside of PCV

Source: Progress status of R&D projects and direction for next period
    (METI, Secretariat of the Team for Countermeasures for Decommissioning and Contaminated Water Treatment (February 23, 2017))
(PDF page 5)

Results & performance by fiscal year
  • FY 2018
  • FY 2017
  • FY 2016
  • FY 2015
  • FY 2014
  • FY 2013
  • FY 2012
Results & performance for individual projects, etc. (Archives)

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  • Investigation and development plan
  • Technology for access inside the pedestal (A series inspections, verification at Unit 2)
  • A1 Inspection: CRD rail status inspection (finished plant verification)
  • A2 Inspection: Inspection of condition of platform inside pedestal
  • Development of technology for access to pedestal exterior and plant verification (B series inspections, verification at Unit 1)
  • B1 Inspection: Inspection of condition above grating on pedestal exterior first floor
Development of Sampling Technologies for Retrieving Fuel Debris and Internal Structures(Project of Decommissioning and Contaminated Water Management)
Summary

We develop technologies of sampling of actual fuel debris, to contribute to criticality control, equipment design and rationalization of construction procedure for the construction of fuel debris retrieval.

Action items
  1. Making of development plan of sampling technologies of fuel debris and sampling plan
  2. Development of equipment/system for sampling fuel debris in PCV
    (1) Development of collection device for small volume sampling
    (2) Development of equipment/system for sampling
    • Access equipment
    • Access route construction equipment
    • Sample cutting/collection equipment
    • Neutron monitor system
    • Remote transportation carriage
Implementing organizations

 Implemented by IRID.

Implementation plan

Targeted process: Development of sampling technologies for retrieving fuel debris and internal structures

Source: FY 2019 Research and Development Plan for Decommissioning
    (METI, Secretariat of the Team for Countermeasures for Decommissioning and Contaminated Water Treatment (February 28, 2018))
(PDF page 10)

Results & performance by fiscal year
  • FY 2019
  • FY 2018
  • FY 2017
Fuel Debris Detection Technology (Using Muon) (Project of Decommissioning and Contaminated Water Management Finished/suspended December 2015)
Summary

It is important to understand the location and amount of fuel debris inside the reactor for 1F decommissioning. However, because the fuel and fuel debris within the RPV is in an extremely highly radioactive environment, it is difficult to observe directly now. Therefore, we developed observation technology utilizing cosmic ray muons that were thought to be an effective non-destructive detection technology, to detect the locations of fuel and fuel debris inside the RPV relatively quickly.

Action items
  1. Development and verification of detection technology utilizing muon penetration method (verification in Unit 1)
  2. Verification of detection technology utilizing muon scattering method (verification in Unit 2)
Implementing organizations

  Implemented by IRID.

Implementation plan

Targeted process: Fuel debris detection technology (muon) utilization

Source: Progress status of R&D projects and direction for next period
    (METI, Secretariat of the Team for Countermeasures for Decommissioning and Contaminated Water Treatment (February 26, 2015))
(PDF page 8)

Results & performance by fiscal year
  • FY 2017
  • FY 2016
  • FY 2015
  • FY 2014
Results & performance for individual projects, etc. (Archives)

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Completed projects of others

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Development of technology for non-destructive detection of radioactive materials accumulated inside the Suppression Chamber, etc. (Project of Decommissioning and Contaminated Water Management)
Summary

We developed estimation and measurement methods to estimate the accumulation condition for radioactive materials that might exist inside suppression chambers (S/C), in order to provide necessary information on radioactive materials (whether radioactive materials are necessary or not, etc.) for repair work (water leakage stoppage) on S/C.

Action items
  1. Create development plan
  2. Radioactive materials displacement scenarios
  3. Impact assessment of radioactive materials on water leakage stoppage materials
  4. Development of technology for detecting radioactive materials
Implementing organizations

Implemented by IRID.

Results & performance by fiscal year
  • FY 2014
Inspection inside PCV using small inspection robots (TEPCO effort)
  • Results of inspection inside Fukushima Daiichi NPS Unit 3 PCV (October 22, 2015) (TEPCO)
  • Inspection of Unit 3 PCV equipment hatches using small inspection equipment (robots) (November 27, 2015) (TEPCO)

R&D efforts (related basic and generic research)

<Remote technology for inspection and measurement>

Development of inspection technology (Decommissioning Basic Research: Human resource development program at Tohoku University- Basic research into reliability maintenance of PCV and buildings, etc., and waste processing and disposal, and core human resource development program for decommissioning)
Remote technology (Decommissioning Basic Research: Human resource development program at Tohoku University- Basic research into reliability maintenance of PCV and buildings, etc., and waste processing and disposal, and core human resource development program for decommissioning)
Research on remote operations technology (Decommissioning Basic Research: Human resource development program at University of Tokyo- Comprehensive human resource development for decommissioning based on remote operations technology and nuclide analysis technology) (PDF)
Remote measurement technology (Decommissioning Basic Research: Human resource development program at Tokyo Institute of Technology, - Advancements in skilled human resource development for and basic research on decommissioning engineering) (PDF)


<Fuel debris detection technology related to (muons) >

Development of non-destructive onsite detection technology (JAEA research: Preliminary tests for visualizing structures inside HTTR) (PDF)
Muon radiography (Research at Nagoya University: Inspections inside reactors by muon radiography using nuclear emulsion plates at Fukushima Daiichi NPS Units 2 and 5) (PDF)

Plant investigation, measurement date, and information

Efforts to understand the plant status at each of Units 1 to 3, and for fuel debris retrieval (February 27, 2024)

(METI, Secretariat of the Team for Countermeasures for Decommissioning and Contaminated Water Treatment)

Plant-related parameters
Fukushima Daiichi NPS survey map
Common data presented by Benchmark Study of the Accident at the Fukushima Daiichi Nuclear Power Plant (BSAF) related to accident progression analysis according to OECD/NEA
Information Portal for the Fukushima Daiichi Accident Analysis and Decommissioning Activities
Collection of figures of data on in-core situation (Updated regularly, August 2018)
  • Figures of temperature, dose rate, amount of water injection, etc. in each Unit (PDFWord file)
Collection of links to data on in-core situation ( January 8, 2020)
Chronology (Events after the accident, in-core situation, etc.)(Updated regularly, September 2018)

Other related information

Use of robot technology (TEPCO)