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Lessons From Fukushima: An Assessment of the Investigations of the Nuclear Disaster

Published online by Cambridge University Press:  07 May 2025

Kerstin Lukner  and
Alexandra Sakaki
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Abstract

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Following the Fukushima nuclear disaster of 2011, the Japanese Cabinet, the Japanese Diet, a private-sector group as well as the operator of the Fukushima Daiichi nuclear facility, TEPCO, each set up an investigation commission to examine the causes of the accident, scrutinize the crisis response and make recommendations for future policies. This article provides some background on the four commissions and then examines and assesses the contents of the reports. Four key conclusions emerge from the analysis. Firstly, the establishment of the commissions was accompanied by immense mistrust, as each of the initiators suspected bias in the other inquiries. Secondly, the comparison demonstrates that while biases can be detected to some extent, the four reports overall agree in their identification of fundamental issues and crucial problems. Thirdly, the article maintains that the four reports used in combination convey a more complete picture than any single one of them. A comparison of the reports highlights diverging interpretations and differing degrees of criticism, while exposing open questions and unresolved issues. Finally, the article argues that the four investigation reports can serve as important reference points, enabling critical assessments of reforms currently undertaken in Japan's nuclear power administration and crisis management system.

Type
Research Article
Information
Asia-Pacific Journal , Volume 11 , Issue 19 , May 2013 , e2
Creative Commons
Creative Common License - CCCreative Common License - BYCreative Common License - NCCreative Common License - ND
This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivatives licence (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is unaltered and is properly cited. The written permission of Cambridge University Press must be obtained for commercial re-use or in order to create a derivative work.
Copyright
Copyright © The Authors 2013

References

Notes

1 The authors would like to thank Matthias Korpak for his valuable research assistance during his internship at SWP. Thank you also to Jeff Kingston, Thomas Berger and Axel Klein for helpful comments and suggestions on earlier drafts of this paper.

2 Michiyo Nakamoto, Japan looks set to restart its nuclear power programme, Financial Times, 4 Januar 2013.

3 There are, however, a few comparative articles in Japanese, see especially: Keizai sangyō chōsashitsu, Issue Brief: Fukushima daiichi genpatsu jiko to 4tsu no jiko chōsa iinkai [The Fukushima Daiichi nuclear accident and the four accident investigation commissions], Kokuritsu kokkai toshokan Issue Brief, No. 756, August 23, 2012, here (accessed December 14, 2012); Yomiuri Shimbun, 4tsu no jikochōhōkoku hikaku [Comparison of the four accident investigation reports], July 24, 2012; Nikkei Shimbun, Kenshō: Genpatsu jikochō hōkokusho [Examination: The Nuclear Accident Investigation Reports], July 29, 2012.

4 None of the four commissions addressed the fundamental question of whether Japan should continue to rely on nuclear power in its energy mix.

5 Cabinet Secretariat, Establishment of the Investigation Committee on the Accident at Fukushima Nuclear Power Stations of Tokyo Electric Power Company, Cabinet Decision, May 24, 2011, here (accessed January 10, 2013).

6 Secretariat, Establishment of the Investigation Committee, May 24, 2011.

7 Cabinet Secretariat, Remarks by the Prime Minister Naoto Kan at the First Meeting of the Investigation Committee on the Accident at the Fukushima Nuclear Power Stations of Tokyo Electric Power Company, June 7, 2011, here (accessed January 28, 2013).

8 Cabinet Secretariat, Remarks by the Prime Minister, June 7, 2011.

9 Cabinet Secretariat, Establishment of the Investigation Committee, May 24, 2011.

10 Page numbers for all reports refer to the Japanese language reports. See Yomiuri Shimbun, 4tsu no jikochōhōkoku hikaku, July 24, 2012.

11 Yomiuri Shimbun, 4tsu no jikochōhōkoku hikaku, July 24, 2012.

12 Cabinet Secretariat, Establishment of the Investigation Committee, May 24, 2011.

13 Asahi Shimbun, Fukushima Daiichi Genpatsuno jikochōsai, 12gatsu ni chūkan hōkoku [Interim Report by Investigation Committeee on Fukushima Daiichi Nuclear Accident in December],September 28, 2011.

14 See Kakizawa Mito's remarks in the Lower House Diet session on May 23, 2011 (All Diet discussions can be accessed at http://kokkai.ndl.go.jp/).

15 See Kusakawa Shōzō's remarks in the Lower House Diet session on October 27, 2011.

16 See Nakasone Hirofumi's remarks in the Lower House Diet session on September 15, 2011.

17 Asahi Shimbun, (Shasetsu) Genpatsujikochō: atarashii kokkai no shikinseki [(Editorial) Investigation on Nuclear Accident: Litmus test for new Diet], October 1, 2011.

18 See the remarks by Minister of Economy, Trade and Industry, Kaieda Banri in the Lower House Diet session on August 25, 2011.

19 See remarks by Matsumura Yoshifumi in the Lower House Diet session on August 25, 2011.

20 National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission, ‘About’, Undated, here (accessed February 10, 2013).

21 On the selection process, see Upper House of Diet, Tokyo Denryoku Fukushima Genshiryoku Hatsudensho Jiko ni kakawaru ryōgiin no giinuneiiinkai no gōdōkyōgikai - Tokyo Denryoku Fukushima Genshiryoku Hatsudensho Jikochōiinkai. [Joint meeting of the leading parliamentary group on the TEPCO Fukushima nuclear power plant accident - TEPCO Fukushima nuclear power plant accident investigation committee], January 18, 2012, here (accessed February 3, 2013).

22 National Diet of Japan, The Official Report of the Fukushima Nuclear Accident Independent Investigation Commission - Executive Summary, 2012, here (accessed April 4, 2013), from heron referred to as ‘Diet Final Summary’, p. 10.

23 Diet Final Summary, p. 11.

24 Asahi Shimbun, Kokkai genpatsu jikochō - Tsuyoi kengen, gensoku kōkai,tōmeisei ni hairyo [Diet nuclear accident investigation -Strong authorityand principle of being open to publicin consideration of transparency], September 29, 2011.

25 Diet Final Summary, p. 20.

26 Rebuild Japan Initiative Foundation, Purpose of the Establishment of the Rebuild Japan Initiative Foundation, undated, http://rebuildjpn.org/en/about-us/purpose/ (accessed February 3, 2013).

27 Funabashi was inspired by the investigation commissions set up by the US National Aeronautics and Space Administration (NASA) to look into the accidents involving the space shuttles Challenger and Columbia. See Asahi Shimbun, Interview/ Yoichi Funabashi: Fukushima nuclear crisis revealed Japan's governing defects, February 29, 2012, here (accessed January 25, 2013).

28 Asahi Shimbun, Interview/ Yoichi Funabashi, February 29, 2012.

29 Rebuild Japan Initiative Foundation, Yoku aru go-shitsumon [Frequently asked questions], undated, here (accessed February 3, 2013). The Foundation has not release specific information on donors.

30 Asahi Shimbun, Interview/ Yoichi Funabashi, February 29, 2012.

31 Rebuild Japan Initiative Foundation, Yūshikisha iinkai [Expert committee], undated, here (accssed February 3, 2013).

32 Koichi Kitazawa, Message regarding Investigation, undated, here (accessed February 3, 2013).

33 Kenji Yamaji, My Thoughts after Participation in an Independent Investigation of the Fukushima Nuclear Accident, July 18, 2012, here (accessed January 15, 2013).

34 A three-page summary is available in English. Rebuild Japan Initiative Foundation, Independent Panel Issues Report on Fukushima Nuclear Accident, March 1, 2012, here (accessed April 22, 2013).

35 Yomiuri Shimbun, 4tsu no jikochōhōkoku hikaku, July 24, 2012.

36 Asahi Shimbun, Interview/ Yoichi Funabashi, February 29, 2012.

37 See foreword in: TEPCO, Fukushima Nuclear Accident Analysis Report (Interim Report), 2011, here (accessed April 4, 2013), hereafter referred to as ‘TEPCO Interim Full’.

38 See foreword in: TEPCO Interim Full.

39 Leslie Corrice, March 5, 2012, „A Fukushima investigative scorecard”, The American Nuclear Society's ‘Nuclear Café’, http://ansnuclearcafe.org/2012/03/05/a-fukushima-investigative-scorecard.

40 Jiji Press, Tōden jiko kenshōi wa ‘kengen naki kateikyōshi’ = TV kaigi mo mizu - Yagawa Iinchō [TEPCO accident inspection is (like) ‘tutor without rights’ = Commission chairman Yagawa - Not even watched TV conference], July 3, 2012.

41 Jiji Press, Tōden jiko kenshōi, July 3, 2012.

42 Jiji Press, Tōden jiko kenshōi, July 3, 2012.

43 Jiji Press, Tōden jiko kenshōi, July 3, 2012.

44 Investigation Committee on the Accident at Fukushima Nuclear Power Stations of Tokyo Electric Power Company, Interim Report, December 2011, here (accessed April 4, 2013), hereafter referred to as ‘Cabinet Interim Full’, p. 38.

45 Cabinet Interim Full, p. 43.

46 Cabinet Interim Full, p. 43.

47 Cabinet Interim Full, p. 25.

48 National Diet of Japan, Fukushima Nuclear Accident Independent Investigation Commission Final Report, 2012, here (accessed April 4, 2013), from heron referred to as ‘Diet Final Full’, Introductory chapter, p. 12.

49 Diet Final Summary, p. 17.

50 Diet Final Full, Chapter 2, p. 46.

51 Fukushima genpatsu jiko dokuritsu kenshō iinkai, Chōsa Kenshō Hōkokusho [Report on Inquiry and Investigation], March 2012, Tokyo: Discover/ Rebuild Japan Initiative Foundation (RJIF), hereafter referred to as ‘RJIF’, p. 41.

52 RJIF, p. 37.

53 TEPCO, Fukushima Nuclear Accident Analysis Report (Final Report), June 20, 2012, here (accessed April 3, 2013), hereafter referred to as ‘TEPCO Final Full’, p. 43.

54 Investigation Committee on the Accident at Fukushima Nuclear Power Stations of Tokyo Electric Power Company, Final Report, July 2012, here (accessed April 4, 2013), hereafter referred to as’CabinetFinal Full’, p. 476.

55 Cabinet Final Full, p. 476.

56 Cabinet Final Full, p. 424.

57 Cabinet Final Full, p. 493.

58 Cabinet Final Full, p. 488.

59 Cabinet Interim Full, p. 554.

60 Investigation Committee on the Accident at Fukushima Nuclear Power Stations of Tokyo Electric Power Company, Executive Summary of the Interim Report, December 2011, here (accessed April 4, 2013), hereafter referred to as ‘Cabinet Interim Summary’, p. 18.

61 Investigation Committee on the Accident at Fukushima Nuclear Power Stations of Tokyo Electric Power Company, Executive Summary of the Final Report, July 2012, here (accessed April 4, 2013), hereafter referred to as ‘Cabinet Final Summary’, p. 23.

62 Cabinet Final Full, p. 502-503.

63 Diet Final Full, Introductory chapter, p. 16; see also Keizai sangyō chōsashitsu, Issue Brief: Fukushima daiichi genpatsu jiko to 4tsu no jiko chōsa iinkai [The Fukushima Daiichi nuclear accident and the four accident investigation commissions], Kokuritsu kokkai toshokan Issue Brief, No. 756, August 23, 2012, here (accessed December 14, 2012), p. 2.

64 Diet Final Full, Introductory chapter, p. 10.

65 Diet Final Summary, p. 16.

66 Diet Final Summary, p. 43. Some observers noted that the chairman's message at the beginning of the report differed with regards to key accident causes in the Japanese and English versions. The English version argues the disaster's causes are found in Japanese culture, characterized by “reflexive obedience” or “reluctance to question authority.” (Diet Final Full, p. 9) The Japanese version is more vague, not directly mentioning culture as a factor. As the chairman's message is not necessarily a consensus product of all investigation members, it is not considered in this paper.

67 Diet Final Summary, p. 43.

68 See Nikkei Shimbun, Kenshō: Genpatsu jikochō hōkokusho, July 29, 2012.

69 Diet Final Full, Chapter 5, p. 14 and Chapter 1, p. 45.

70 Diet Final Full, Chapter 5, p. 57.

71 Diet Final Summary, p. 17.

72 Diet Final Full, Introductory chapter, p. 16.

73 Yomiuri Shimbun, 4tsu no jikochōhōkokuhikaku, July 24, 2012.

74 Diet Final Summary, p. 43.

75 Diet Final Full, Chapter 5.

76 Diet Final Full, Chapter 5, p. 14.

77 RJIF, pp. 383-384.

78 RJIF, p. 386.

79 RJIF, p. 246.

80 RJIF, p. 246.

81 RJIF, p. 248.

82 RJIF, p. 246.

83 RJIF, p. 385.

84 RJIF,p. 248.

85 RJIF, p. 248.

86 RJIF, p. 292.

87 RJIF, p. 251.

88 RJIF, p. 306.

89 RJIF, p. 292.

90 TEPCO Final Full, p. 447.

91 TEPCO, Fukushima Nuclear Accident Analysis Report (Summary), June 20, 2012, here (accessed April 4, 2013), hereafter referred to as ‘TEPCO Final Summary’, p. 8.

92 TEPCO Final Summary, p. 11.

93 Yomiuri Shimbun, 4tsu no jikochōhōkoku hikaku, July 24, 2012.

94 Cabinet Interim Full, p. 568.

95 Cabinet Interim Full, p. 569.

96 Cabinet Final Full, p. 434.

97 Cabinet Final Summary, p. 6.

98 Cabinet Final Summary, p. 6.

99 Cabinet Final Full, p. 219.

100 Cabinet Final Summary, p. 5.

101 Cabinet Final Full, p. 498.

102 Cabinet Final Full, p. 498.

103 Cabinet Final Full, p. 223.

104 Cabinet Final Summary, p. 9.

105 Cabinet Final Summary, p. 9.

106 Cabinet Final Summary, p. 8.

107 Diet Final Full, Introductory chapter,p. 13.

108 Diet Final Summary, p. 33.

109 Diet Final Full, Introductory chapter,p. 13.

110 Diet Final Summary, p. 33.

111 Diet Final Full, Chapter 3,p. 67.

112 Diet Final Full, Chapter 3,p. 33.

113 Diet Final Summary, p. 18.

114 Diet Final Full, Chapter 3,p. 65.

115 Diet Final Summary, p. 34.

116 Diet Final Summary, p. 35.

117 Diet Final Full, Chapter 3,p. 64.

118 Diet Final Full, Chapter 3,p. 65.

119 Diet Final Full, Chapter 3,p. 64.

120 RJIF, p. 98.

121 RJIF, p. 98.

122 RJIF, p. 74.

123 RJIF, pp. 74, 99.

124 RJIF, pp. 74, 99.

125 RJIF, pp. 100-101.

126 RJIF, p. 102.

127 RJIF, p. 74.

128 RJIF, p. 392.

129 RJIF, pp. 391-392.

130 TEPCO Final Full, p. 438.

131 TEPCO Final Summary, 13.

132 TEPCO Final Full, pp. 80-81.

133 TEPCO Final Full, pp. 439-440.

134 TEPCO Final Full, p. 440.

135 TEPCO Final Full, p. 440.

136 TEPCO Final Summary, 45.

137 TEPCO Final Summary, p. 45.

138 Some media reported incorrectly that the Prime Minister ordered a halt to the ongoing seawater injection at reactor unit 1, which required cooling due to the cessation of cooling systems. However, the investigation reports find that Kan was not informed that plant manager Yoshida had already started the injection when deliberating the pros and cons with his advisers. Learning of the commencement of the seawater injection, a TEPCO liaison at the Kantei informed the company that Kan had not yet given explicit approval and that the mood at the Kantei seemed against the injection. Eventually, Kan ordered the injection, but it did not make any difference because the plant manager ignored demands by TEPCO's Headquarters to halt seawater injections.

139 Cabinet Interim Full, 192-197.

140 Diet Final Full, Chapter 3, 53-55.

141 RJIF, 82-32. RJIF, 391-392.

142 TEPCO Final Full, 183-184. TEPCO Final Full, 439-440.

143 Cabinet Final Summary, p. 8.

144 Diet Final Full, Chapter 3,p. 53.

145 Assessment made with reference to description of this situation in Diet Investigation Report, RJIF, p. 97.

146 TEPCO Final Full, p. 98.

147 Cabinet Interim Full, p. 83.

148 Diet Final Full, Chapter 3,p. 55.

149 RJIF, p. 393.

150 TEPCO Final Full, pp. 101-116.

151 The Emergency Response Support System forecasts the release of radioactive emission, while SPEEDI predicts its dispersal based on the ERSS data being provided. ERSS failed to function during the accident, though.

152 Cabinet Final Summary, pp. 10-11.

153 Cabinet Interim Summary, p. 10.

154 Diet Final Summary, p. 39.

155 RJIF, pp. 177-179.

156 Cabinet Interim Summary, p. 11.

157 Diet Final Summary, p. 38.

158 RJIF, p. 392.

159 Cabinet Interim Summary, pp. 12-13.

160 Diet Final Summary, p. 36.

161 RJIF, pp. 144-145.

162 TEPCO Final Summary, p. 47.

163 TEPCO Final Full, pp. 101-116.

164 See table 2 for references and Kokuritsu kokkai toshokan Issue Brief, No. 756, August 23, 2012, p. 16.

165 ERSS failed to function during the accident.

166 See table 2 for references.

167 Nikkei Shimbun, Kenshō: Genpatsu jikochō hōkokusho, July 29, 2012; Yomiuri Shimbun, 4tsu no jikochōhōkokuhikaku, July 24, 2012.

168 See also final report chapter „Chairperson's Remarks”, Government Final Full, pp. 522-529.

169 CabinetFinal Full, pp. 509-510.

170 Government Final Full, p. 509

171 Government Final Full, p. 513.

172 Government Final Full, pp. 517-520.

173 Government Final Full, pp. 512-513.

174 For similar criticism see Yomiuri Shimbun, 4tsu no jikochōhōkokuhikaku, July 24, 2012.

175 For all recommendations see Diet Final Summary, pp. 18-20.

176 Diet Final Summary, p. 18.

177 RJIF, pp. 387-389.

178 RJIF, p. 394.

179 TEPCO Final Summary, 47-52.

180 TEPCO Final Full, pp. 483-484.

181 TEPCO Final Full, pp. 483.

182 Cabinet Final Full, p. 520; Diet Final Summary, p. 20; RJIF 2012, p. 397

183 For an overview of the NRA, see the leaflet Nuclear Regulation Authority, Nuclear Regulation for People and the Environment, November 2012, here (accessed March 15, 2013).

184 Mari Yamaguchi, Ex-PM slams utility over Japan nuke crisis video, Associated Press, August 8, 2012, here (accessed April 23, 2013).

185 Japan Times, TEPCO finally admits nuke crisis avoidable, October 14, 2012, here (accessed April 23, 2013).

186 Asahi Shimbun, Japanese operator in most frank admission over nuclear disaster, December 14, 2012, here (accessed April 23, 2013)

187 Asahi Shimbun, Nuke plant operators put tab on new safety standards at 1 trillion yen, February 27, 2013, here (accessed March 2, 2013).

188 With approximately 500 employees, the NRA is still much smaller than the US Nuclear Regulatory Commission, which has about 3000 staff members. See Asahi Shimbun, A guide to Japan's new nuclear regulatory agency, February 14, 2012, here (accessed March 20, 2013).

189 Jeff Kingston, Power Politics: Japan's Resilient Nuclear Village, Asza-Pacific Journal, Vol. 10, Issue 43, No. 1, October 29, 2012.

190 Asahi Shimbun, Government rewrites rulebook for nuclear disasters, September 7, 2012, here (accessed March 19, 2013).

191 Asahi Shimbun, Criticism, doubts greet new Diet panel on nuclear issues, April 9, 2013, here (accessed April 30, 2013)

192 Nikkei Shimbun, ‘Genshiryoku giseichō no senmonsei kōjō o’ seifu yūshikisha kaigi ga hōkokusho [Government expert conference in report: ‘Need to improve expertise within nuclearregulation authority’], March 6, 2013, here (accessed March 8, 2013).

193 Tōkyo Denryoku Fukushima genshiryoku hatsudensho jiko ni kanshite kokkai oyobi seifuni mōkerareta iinkai no teigen no forōappu ni kan suru yūshikisha kaigi, Hōkokusho [Report], March 2013, here (accessed April 3, 2013), p. 13.

194 Tōkyo Denryoku Fukushima genshiryoku hatsudensho jiko forōappu kaigi, Hōkokusho, p. 5.

195 Tōkyo Denryoku Fukushima genshiryoku hatsudensho jiko forōappu kaigi, Hōkokusho, p.13.

196 Asahi Shimbun, Japanese regulators to investigate nuclear crisis, March 28, 2013, here (accessed April 3, 2013).