Grasping of situation in core
The temperature inside the PVC of each reactor is continuously low and it has been proven by measuring radioactive materials that recriticality has not occurred. Thus, fuel debris has been cooled and is in a stable condition.
On the other hand, access to the inside of buildings is so restricted that there are technical difficulties to assess internal conditions visually.
Therefore, in addition to proceeding with practical research while developing remote-controlled observation and measuring devices which are capable of being inserted into the PCV through a penetration for locating fuel debris in particular places and tomographic technology for nuclear reactors using muon measurement, it is necessary to develop comprehensive analysis and evaluation, taking into account data and information gathered through research on temperature measurement at sites and distribution of radioactive materials and estimates by accident progression analysis code.
The whole picture of decommissioning strategies and issues
The whole picture of decommissioning strategies and issues -grasping of situation in core-
R&D efforts
Comprehensive analysis and evaluation of fuel debris and FP status
Device/equipment development /demonstration for the full scale practical system research and measurement
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)
- Current Status of Fukushima Daiichi NPS (As of January 25, 2024)
Plant-related parameters
- Plant-related parameters (Summary table) (PDF)
- Temperature parameters (Chart) Real-time data
- Unit 1 Temperature in the RPV (PDF)
- Unit 1 Temperature in the PCV (PDF)
- Unit 2 Temperature in the RPV (PDF)
- Unit 2 Temperature in the PCV (PDF)
- Unit 3 Temperature in the RPV (PDF)
- Unit 3 Temperature in the PCV (PDF)
- Fukushima Daiichi NPS plant data collected at the time of the accident (TEPCO)
- The Great East Japan Earthquake and Current Status of Nuclear Power Station(TEPCO)
- Outline of the plant (IRID) (PDF) only Japanese page
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)
Collection of links to data on in-core situation ( January 8, 2020)
- Grasping of fuel debris (PDF) Only Japanese page
- Stability of fuel debris (PDF) Only Japanese page
- Operation safety (PDF) Only Japanese
- Retrieval of fuel debris and others (PDF) Only Japanese page
Chronology (Events after the accident, in-core situation, etc.) (Updated regularly, September 2018)
- Chronology of Fukushima Daiichi NPS (Excel File)
Other related information
Fukushima Daiichi NPS accident background and lessons: Estimations of the accident progression at each Unit (“Why did the accident occur?” and “Accident background”) (TEPCO)
- Accident background
- Why did the severe accident occur at Unit 1?
- Why did the severe accident occur at Unit 2?
- Why did the severe accident occur at Unit 3?
- Why did the hydrogen explosion occur at Unit 4?
- Accident process
- Accident process at Unit 1
- Accident process at Unit 2
- Accident process at Unit 3
- Accident process at Unit 4
- Reactor core conditions at Fukushima Daiichi NPS Units 1 to 3 (March 12, 2012) (PDF)
TEPCO Fukushima Daiichi NPS accident-related technology workshop
- Guidance materials
- Lecture materials