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Ensuring safety for fuel debris retrieval (2) (Criticality safety control)

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

Completed projects

Development of Criticality Control Technologies of Fuel Debris (Project of Decommissioning and Contaminated Water Management)
Summary

We review criticality scenario, potential evaluation of criticality and behavior evaluation at the time of criticality arrival every units reflecting the most recent information on comprehensive analysis/evaluation results of conditions in the reactor. Also, we develop, design, and build detection systems to monitor fuel debris sub-criticality by monitoring fission products for the purpose of stratified criticality control, and perform feasibility tests and confirm operability in a highly irradiated environment. And then in order to prevent criticality during fuel debris retrieval, we study development of neutron absorbents and operating methods to use them.

Action items
  1. Establishment of criticality evaluation technique
    • Study of criticality control method
    • Study of criticality control and criticality scenario
  2. Development of criticality control technology
    • Sub-criticality monitoring methods
    • Re-criticality detection technologies
    • Criticality prevention technologies
Implementation organization

Implemented by IRID.

Implementation plan

Target process: Development of criticality control technologies of fuel debris

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 14)

Results & performance by fiscal year
  • FY 2017
  • FY 2016
  • FY2015
  • FY 2014
  • FY 2013
  • FY 2012
Results & performance for individual projects, etc. (Archives)

R&D efforts (related basic and generic research)

Recriticality accident analysis during debris retrieval (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)
Measures to ensure sub-criticality during debris retrieval (Decommissioning Basic Research: Human resource development program at Tokyo City University - Advancements in skilled human resource development for and basic research on decommissioning engineering) (PDF)

Plant investigation, measurement data, and information

Efforts to understand the plant status at each of Units 1 to 3, and for fuel debris retrieval (Updated monthly, June 10, 2020) new

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

Plant-related parameters
Fukushima Daiichi Nuclear Power Station 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 (Updated monthly, January 8, 2020) new
Chronology (Events after the accident, in-core situation, etc.) (Updated regularly, September 2018)

Other related information

<Updated regularly>