1. Although some details of the accidents of Fukushima Daiichi Nuclear Power Plant are still not well known, the sequences, causes, and consequences of the accidents have been basically clarified by the efforts of several investigation committees established in Japan.

2. The fission products released to the environment were estimated by the severe accident analysis code from inside the reactor core, and also by the atmospheric dispersion simulations code by coupling with environmental monitoring data in the reverse estimation method from outside the plant. The estimated release amount of 131I is of the order of 120–160 PBq, and that of 137Cs is of the order of 8–15 PBq for both estimations.

3. Lessons learned from the accident identified by investigation committees cover a wide spectrum of insufficient measures, such as for earthquake and tsunami, station blackout, severe accident management, common cause accident at multiple unit sites, education and training, chain of command at the accident, disaster prevention, and safety regulation system. These lessons should be shared all over the world for the higher level of safety assurance of current reactors, and advanced reactors without the need of evacuation in principle should be developed for the future.

Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License, which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.


1. Independent investigation commission on the Fukushima daiichi nuclear accident (Feb. 2012) investigation and verification report

2. The Tokyo Electric Power Company Inc. (June 2012) Fukushima nuclear accident analysis report (Final Report)

3. The National Diet of Japan (July 2012) The Official Report of the Fukushima Nuclear Accident Independent Investigation Commission

4. Government of Japan (July 2012) Final report of the investigation committee on the accident at Fukushima nuclear power stations of Tokyo Electric Power Company

5. Nuclear and Industrial Safety Agency (2011) Discharge of radioactive materials to the environment (Chapter VI). Report of Japanese government to the IAEA ministerial conference on nuclear safety

6. Hoshi H et al. (April 2011) Computational analysis on accident progression of Fukushima Daiichi NPS. PSAM topical conference in Tokyo, Japan

7. Chino M et al (2011) Preliminary estimation of release amounts of 131I and 137Cs accidentally discharged from the Fukushima Daiichi Nuclear Power Pplant into the atmosphere. J Nucl Sci Technol 48:1129–1134

8. Terada H et al (2012) Atmospheric discharge and dispersion of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant accident. Part II: Verification of the source term and analysis of regional-scale atmospheric dispersion. J Environ Radioact 112:141–154

9. OECD NEA (1995) The Chernobyl reactor accident source term—development of a consensus view. OECD NEA/CSNI/R(95)24.

10. Kondo S (April 2013) Lessons learned from Fukushima for PSAM community: Leadership and responsibility to assess and inform risk for safety assurance. In: PSAM topical conference in Tokyo, Japan

11. Sugimoto J (July 2013) Important severe accident research issues after accident at Fukushima Daiichi Nuclear Power Station. 21st international conference on nuclear engineering. Chengdu, China

12. Fuketa T (March 2013) Proposed regulatory requirements in Japan. Regulatory Information Conference, Bethesda

< Prev   CONTENTS   Next >