The Fukushima Daiichi Nuclear Power Plant Accident: A Provisional Analysis and Survey of the Government s International & Domestic Response

Transcription

1 The Fukushima Daiichi Nuclear Power Plant Accident: A Provisional Analysis and Survey of the Government s International & Domestic Response Kanami Ishibashi 1 On March 11, 2011 at 14:46, Japan was hit by a massive 9.0 earthquake. It left approximately 25,000 people dead or missing 2 and was referred to as the Great East Japan Earthquake. It generated a huge tsunami that triggered the catastrophic accident at the Fukushima Daiichi Nuclear Power Plant owned and operated by the Tokyo Electric Power Company (TEPCO). The magnitude of the accident is estimated to have reached Level 7 on the International Nuclear Event Scale (INES). 3 There were altogether six units in the Fukushima Daiichi Nuclear Power Plant. Half of the reactor units (Nos. 4, 5, and 6) were under periodic inspection and not in operation on that day. The first three reactor units of the power plant were automatically shut down (by the SCRAM function) due to the earthquake. Even though the SCRAM functioned automatically to halt the operation of the reactor units, the nuclear reactors remained hot for some time afterwards and needed to be cooled down as soon as possible. However, due to the loss of the main electrical power because of the earthquake, only emergency electrical power was available for cooling. The nuclear power plant was subsequently hit by a large tsunami that was estimated to be 14 to 15 meters high. 4 The tsunami submerged all of 1 Associate Professor, Tokyo University of Foreign Studies 2 Nuclear Emergency Response Headquarters Government of Japan, Report of Japanese Government to the IAEA Ministerial Conference on Nuclear Safety: The Accident at TEPCO s Fukushima Nuclear Power Stations, Contents of summary, at 4 (2011), available at go.jp/foreign/kan/topics/201106/pdf/00-2_outline.pdf [hereinafter Contents of Summary]. 3 Id. at Id. at

2 150 (2011) 17 Asian Yearbook of International Law the emergency electricity generation facilities except for that of unit 6. 5 It became impossible for the intake water to cool the reactors and the nuclear waste pool. Most importantly, the nuclear reactor fuel rods were exposed for hours (unit 1 for 14 hours) without cooling water. This accelerated the onset of the core meltdown. 6 As a result, the fuel rods of units 1, 2, and 3 became overheated and eventually their cores melted down. In addition, the operators failed to ventilate the pressures inside the containment vessels contrary to normal procedure in nuclear plant accidents. Consequently, the pressure within the containers reached a critical level, and eventually a hydrogen explosion occurred inside the buildings that housed the reactors of units 1, 3, and 4 which also caused significant damage to the upper areas of the reactor buildings. This released radioactive substances outside. However in unit 4, all the fuel rods were transferred to the spent fuel pool for periodic inspection and therefore it is unclear whether the release of radioactive substances was caused by the explosion of unit 4. Also in unit 2, there was a hydrogen explosion near the suppression chamber. The amount of radioactive release was measured in iodine 131 up to 900 Peta Bq, which was almost equal to one-sixth of that of the Chernobyl nuclear power plant accident. It spread to 1,800 square kilometers in Fukushima Prefecture where people were exposed to more than 5 msv per year in the air dosage rate. 7 To respond to such accidents, the Japanese government developed the Emergency Response Support System (ERSS). This is a remotely-monitored computer system that observes the condition of machines in affected areas, analyzes the degree of the emergency situation, and predicts its process. It 5 Id. 6 Id. at 10. Water injection seemed to have stopped for 14 hours and 9 minutes, After the total loss of AC power at 15:37 on March 11 until the start of freshwater injections at 5:46 on March 12. From the results of the evaluation by NISA (on the assumption that the HPCI was not operating), it seems that the fuel was exposed due to a drop in the water level around 17:00 on March 11, and that the core melt started afterwards. 7 Nuclear Accident Independent Investigation Commission, The Official Report of Fukushima Nuclear Accident Independent Investigation Commission, at 19 (2012), available at report.pdf.

3 Ishibashi: The Fukushima Daiichi Nuclear Plant Accident 151 was operated by the Nuclear and Industrial Safety Agency (NISA) and the Incorporated Administrative Agency Japan Nuclear Energy Safety Organization (JNES). However, the investigation into the accident confirmed by December 2011 that such a system could not fully operate during an emergency because of systemic problems including a lack of information at the source. 8 The Act on Special Measures Concerning Nuclear Emergency Preparedness 9 was enacted after the Tokaimura nuclear accident of September 30, It resulted in the death of two people in the nuclear fuel fabrication facility operated by JCO (formerly Japan Nuclear Fuel Conversion Co.) in Tokaimura, Ibaraki Prefecture. 10 In cases where an abnormal level of radiation is detected, articles 1 and 15(2) of the Act enable the Prime Minister to publically declare the occurrence of a nuclear emergency situation, and to take measures for protecting the lives, physical health, and property of citizens from a nuclear disaster. 11 Under the Act, Prime Minister Naoto Kan declared a nuclear emergency situation on March 11, 2011 at 19:03. The same day at 21:23, he ordered people living within a 3-kilometer radius of the plant to evacuate. 12 People living within a 3 to 10-kilometer radius of the plant were to take shelter indoors. However, the next day, March 12 at 15:36, there was an explosion in unit 1 of the power plant. The containment building was destroyed as the roof and wall blew out, leaving the steel frame exposed. The cause was a hydrogen explosion resulting from the failure to ventilate the pressure of the containment vessel. Nuclear contaminated substances were accidentally released to the air. The Prime Minister responded to this situation by ordering people living within a 20-kilometer radius of the plant to evacuate on March 12, 8 Contents of Summary, supra note 2, at Act on Special Measures Concerning Nuclear Energy Preparedness, Law No. 156 of 1999, available at main?id=106&vm=&re. [hereinafter Act on Nuclear Energy Preparedness]. 10 As compared to the Fukushima accident, the scale of the Tokaimura accident was at level 4 on the International Nuclear Event Scale (INES) and its adverse effects had been kept inside the facility. 11 Act on Nuclear Preparedness, supra note 9, arts. 1, 15(2). 12 Contents of Summary, supra note 2, at 18.

4 152 (2011) 17 Asian Yearbook of International Law 2011 at 18:25. This was followed with an order for the people living within 30-kilometer radius of the plant to take shelter indoors on March 15 at 11: As for the effects on human life and health, though long-term studies are necessary, so far human casualties appear to be low. There were two operators who were engaged in recovering electricity who dipped their shoes into contaminated water of about 400 msv. They evacuated to a hospital, but death or serious injury by radiation exposure has not been reported. 14 Cooling of Reactors and Coping with Meltdown There were reactor meltdowns in units 1 to 3 and a portion of nuclear fuel accumulated at the bottom of the pressure containers. To resolve the problem of the reactors, one of the most urgent and important issues involved cooling the temperature by pouring water into the pressure container and stopping the thermal reaction. It was feared that the accumulated nuclear fuel at the bottom of the pressure container would be released due to container damage. On December 16, 2011, Prime Minister Yoshihiko Noda declared that they successfully made a cold shutdown of the nuclear reactors, as the second step of a planned roadmap towards decommissioning them. Although he explained that the reactors at this stage were safe even if trouble again occurred outside of the reactors, foreign states and the media were quite critical of his announcement. They pointed out that it could be misleading because a cold shutdown of a reactor does not mean there is a safe environment outside the power plants unless the decontamination work has been completed. In fact, water continued to be introduced to keep the reactors cool. 13 Id. The accident escalated as follows: On March 14, there was another explosion in unit 3 and on March 15, there was an explosion in unit 2, also due to the failure to ventilate properly. 14 Fukushima genpatsu 3-goki de sagyo-in 3-nin hibaku 2-ri ga byoin e hanso [Three Workers Exposed to Radiation in Unit 3 of Fukushima Nuclear Power Plant, Two Sent to Hospital], Asahi Shinbun Digital, Mar. 24, 2011, available at asahi.com/special/10005/tky html; but see Contents of Summary, supra note 2, at 22 (The workers exposure was fortunately limited to 2 or 3Sv).

5 Ishibashi: The Fukushima Daiichi Nuclear Plant Accident 153 (1) System for Prediction of Environmental Emergency Dose Information (SPEEDI) issue Another problem arose regarding SPEEDI, a system designed to figure out how to respond to nuclear emergencies that takes into account information at the source, weather conditions, and geological formations. Because the ERSS system, which monitors any changes and transmits that data, is supposed to facilitate a prompt response, but could not fully operate at the time of the accident due to certain systemic problems, SPEEDI was expected to function as an alternative. SPEEDI did make valid predictions for the diffusion of nuclear substances that would spread northwest of the plant, but this information was not made available to the public. As a tragic consequence, about 2,000 people were evacuated to an area where SPEEDI had already predicted as potentially contaminated. Chief Cabinet Secretary Edano indicated that it was regrettable that SPEEDI could not be used and the government should take political responsibility for its failure to use SPEEDI to minimize the adverse impact of the nuclear substances on those evacuated. (2) the establishment of The National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission (NAIIC) for more comprehensive and neutral investigation The NAIIC was created by the Act Regarding Fukushima Nuclear Accident Independent Investigation Commission (NAIIC Act) and established by the National Diet of Japan. Its members are comprised of independent experts. It targeted the following points for analysis in accordance with Article 10 of the NAIIC Act: the direct and indirect causes of the Tokyo Electric Power Company Fukushima nuclear power plant accident; the direct and indirect causes of the damage; and the investigation and verification of the emergency response to both the accident and the subsequent damages. The outcome of investigation will be available in 2012.

6 154 (2011) 17 Asian Yearbook of International Law (3) effect on Japanese energy policy: whether to continue to use nuclear power Before the accident, Japan relied on nuclear power plants to generate electricity because it contributed less to global warming than coal or oil powered thermal plants. Japan planned to export its nuclear power plants to developing countries such as Vietnam under the Agreement between the Government of Japan and the Government of the Socialist Republic of Vietnam for Cooperation in the Development and Peaceful uses of Nuclear Energy that was adopted on January 20, Even after the Fukushima accident, there does not seem to be any change in the policy concerning the export of nuclear power plants because the project was finally approved by the Diet on December 9, 2011 for implementation in However, current public opinion over whether Japan should continuously use nuclear power plants for energy within Japan has been marked by controversy. After the accident, the resumption of operations of suspended nuclear power plants has been problematic. The operation of the Hamaoka Nuclear Power Plant was stopped at Prime Minister Naoto Kan s request on May 6, 2011, 16 and the operation of the Genkai Nuclear Power Plant was shut down on December 25, 2011, leaving only six of Japan s 54 reactors remaining in operation at the time Press Release, Ministry of Foreign Affairs of Japan, Notification for the Entry into Force of the Japan-Viet Nam Nuclear Cooperation Agreement (Dec. 22, 2011), available at 16 Naoto Kan, Prime Minister, Press Conference by Prime Minister Naoto Kan (May 6, 2011), available at 06kaiken_e.html. 17 Mari Iwata, Shutdown Leaves Japan with Six Nuclear Reactors Up, Wall Street Journal, Dec. 25, 2011, available at shutdown-leaves-japan-with-six-nuclear-reactors-up

7 Ishibashi: The Fukushima Daiichi Nuclear Plant Accident 155 Japan s Notification and Report to the International Community As to the accident, Japan s early response from March 11 to December 31, 2011 to the international community and its reaction are as follows: (1) notification to the international community The government of Japan provided briefings every day from March 13 to May 18, 2011 and three days a week after May 19. However, it is regrettable that Japan failed to inform the international community on certain matters. Aside from the emergency vent, Japan was forced to release socalled low-level contaminated water into the sea. At the early stages of the accident, it needed to pour huge quantities of water continuously on the container to cool it. The water became contaminated with nuclear substances and had to be kept in tanks for storage. However, on April 2, 2011, it was discovered that a leakage of highly contaminated water made its way to the sea. To secure space in the storage tanks, low-level contaminated water was intentionally released into the sea. This intentional release of the low-level contaminated water into the sea was not announced and was seriously criticized by the international community. 18 (2) report of the accident and proposal to the international community In June 2011, Japan submitted a report on the Fukushima Daiichi Nuclear Power Plant accident to the ministerial meeting of the International Atomic Energy Agency (IAEA) 19 and in September 2011, to the general assembly of the IAEA. To promote nuclear security in the world, Japan proposed to strengthen the functions of IAEA and international agreements for nuclear safety. Such a proposal was reflected in the 2011 IAEA Action Plan on Nuclear Safety Contents of Summary, supra note 2, at 21-22, Nuclear Emergency Response Headquarters Government of Japan, Report of Japanese Government to the IAEA Ministerial Conference on Nuclear Safety: The Accident at TEPCO s Fukushima Nuclear Power Stations (2011), available at iaea_houkokusho_e.html. 20 International Atomic Energy Agency, IAEA Action Plan on Nuclear Safety, available at

8 156 (2011) 17 Asian Yearbook of International Law that was adopted at the IAEA General Conference. For example, the Action Plan underlined the need for member states to promptly undertake assessments of the safety and vulnerabilities of their nuclear plants, especially in reference to the design of nuclear power plants against site specific extreme natural hazards. 21 The Action Plan also stated the need to improve the effectiveness of the international legal framework which consisted of the Convention on Nuclear Safety; the Joint Convention on the Safety of Spent Fuel Management and the Safety of Radioactive Waste Management; the Convention on the Early Notification of a Nuclear Accident; and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency. The Action Plan even stressed to amend the Convention on Nuclear Safety and the Convention on the Early Notification of a Nuclear Accident. The making of such a proposal appeared to be due to the Japan s delay in informing the international community of the accident and the reaction to it. (3) Support from the international community Japan received letters of sympathy and offers of support to dispatch international disaster relief teams and experts. It accepted emergency supplies and funds, and the support of foreign forces and overseas NGOs. Japan has also been on the receiving end of criticism from the United States, the European Union, China, Russia, Taiwan, and Hong Kong, which have regulated the import of agricultural and industrial goods and travel to Japan. According to the Ministry of Foreign Affairs of Japan, such negative responses have been mostly based on hearsay and the ministry has attempted to explain that many of these views are not based on scientific proof. The Ministry has stated that the air radiation level of Aizu Wakamatsu city in Fukushima Prefecture is the same as that of Seoul and almost the same as that of New York City. Recent Developments and Foreign Policy As mentioned above, Prime Minister Yoshihiko Noda announced that the Fukushima Nuclear Power Plant accident was in the second stage of the planned roadmap for decommissioning reactors. Though the full impact of the accident remains unknown, fortunately, it appears that the risk to 21 Id. at 2.

9 Ishibashi: The Fukushima Daiichi Nuclear Plant Accident 157 human health is low. In any event, Japan must proceed with its planned roadmap for a complete recovery. While it is highly questionable whether Japan will continue to use nuclear energy, it is noteworthy to mention that in 2011, even after the tragic Fukushima accident, Japan proactively proceeded with the necessary domestic procedures, with the approval of the Diet, to conclude bilateral agreements. These agreements are for cooperation in the peaceful uses of nuclear energy with Jordon, 22 Russia, 23 Korea, 24 and Vietnam 25 which aim towards mutual cooperation in the field of nuclear energy including the exportation of nuclear technologies to partner countries. The NAIIC Report and the progress of Japan s effort to deal with this severe disaster in 2012 will be analyzed in the forthcoming volume (volume 18) of the Yearbook. 22 Agreement between the Government of Japan and the Government of the Hashemite Kingdom of Jordan for Cooperation in the Peaceful Uses of Nuclear Energy, Japan-Jordan, Sep. 10, 2010, available at treaty/submit/session179/agree-01.html. 23 Agreement between the Government of Japan and the Government of the Russian Federation for Cooperation in the Peaceful Uses of Nuclear Energy, Japan-Russia, May 12, 2009, available at agree-02.html. 24 Agreement between the Government of Japan and the Government of the Republic of Korea for Cooperation in the Peaceful Uses of Nuclear Energy, Japan-S. Korea, Dec. 12, 2010, available at agree-03.html. 25 Agreement between the Government of Japan and the Government of the Socialist Republic of Viet Nam for Cooperation in the Development and Peaceful Uses of Nuclear Energy, Japan-Viet Nam, Jan. 20, 2011, available at go.jp/policy/treaty/submit/session179/agree-04.html.