One Year On: Assessing Fukushima’s Impact

The March 2011 accident at Japan’s Fukushima Daiichi Nuclear Power Station has shaken confidence in nuclear safety. Carnegie’s James Acton and Mark Hibbs explain why and how the Fukushima accident was, however, preventable.

The Fukushima Accident 

• Its Effects: The accident at Fukushima Daiichi released large quantities of radioactivity into the environment, causing significant human suffering and rendering large stretches of land uninhabitable. The cleanup operation will take decades and cost tens, if not hundreds, of billions of dollars. 


• Nuclear Safety: Unsurprisingly, the Fukushima accident has reignited the ever-contentious debate about the safety of nuclear energy. Critics argue nuclear power is too dangerous to be acceptable. In assessing how safe nuclear can be, it is useful to ask whether an accident was preventable. The two major nuclear accidents prior to Fukushima, Chernobyl in 1986 and Three Mile Island in 1979, were both preventable. 


• Fukushima was Preventable: Acton explained that one year on, there is a growing body of evidence that suggests the accident was the result of failures in hazard assessment and nuclear plant design. Had the plant’s owner, Tokyo Electric Power Company (TEPCO), and Japan’s regulator, the Nuclear and Industrial Safety Agency (NISA), followed international best practices and standards, it is conceivable that they would have predicted the possibility of the plant being struck by a massive tsunami. Even if they had failed to do so, upgrades in plant design in accordance with state-of-the-art safety approaches would have prevented the tsunami from sparking a major accident. The Fukushima accident—like the Chernobyl and Three Mile Island accidents—was therefore preventable.

Hazard Prediction

According to Acton and Hibbs, the methods used by TEPCO and NISA to assess the risk from tsunamis lagged behind international standards in three critical ways:

• Historical Evidence of Disasters: Acton concluded that TEPCO and NISA did not give sufficient attention to historical evidence of large earthquakes and tsunamis in the region surrounding the plant. Specifically, evidence that the region had been inundated about once every 1,000 years by tsunamis (most recently in 869 AD) was not followed up appropriately.


• Tsunami Modeling Procedures: There appears to have been deficiencies in the tsunami modeling procedures used by TEPCO, Acton said. Most importantly, TEPCO did not follow up with sufficient alacrity on preliminary 2008 simulations that suggested the tsunami risk to the plant had been seriously underestimated, he added. These simulations were not reported to NISA until March 7, 2011.


• NISA Inattentiveness:  A fundamental principle of nuclear safety is the existence of an effective and independent regulator to set safety rules and to ensure compliance with them. Japan’s regulators, however, appear to have been inattentive to tsunami risks, Acton said. NISA failed to review simulations conducted by TEPCO and to foster the development of appropriate computer modeling tools. 

How Could the Plant Have Been Protected?

• Protecting the Plant: Hibbs explained that there were several steps that could have prevented a major accident in the event of massive tsunami. TEPCO, encouraged by Japanese regulators, could have taken some or all of the following actions:
  
  
  • Protected emergency power supplies, including diesel generators and batteries, by moving them to higher ground or by placing them in watertight bunkers.
  
  
  • Established watertight connections between emergency power supplies and the plant.
  
  
  • Enhanced the protection of seawater pumps, which were used to transfer heat from the plant to the ocean and to cool diesel generators, and/or constructed a backup means to dissipate heat.


• International Best Practices: Hibbs contended that during the four decades that the Fukushima Daiichi was in operation, regulators and nuclear power plant owners elsewhere in the world were establishing requirements and configuring nuclear power plants in ways that could have potentially have saved the Fukushima Daiichi station from disaster. He highlighted standard design features in European plants in particular that would have better protected Fukushima Daiichi against a station blackout, severe flooding, and the loss of the ultimate heat sink.

Underlying Causes

While there is no single reason for TEPCO and NISA’s failure to follow international best practices and standards, Acton and Hibbs outlined a number of potential underlying causes:

• Regulatory Quality and Independence: NISA’s lack of independence from the government body responsible for promoting nuclear power deterred NISA from asserting its authority to make rules, order safety improvements, and enforce its decisions, Hibbs said.


• Ignoring Safety Threats: Hibbs contended that NISA and TEPCO neglected the threat of a tsunami and also, more broadly, the possibility that power would be lost at a nuclear power plant for a prolonged period. 


• Risk Assessment: Hibbs pointed to Japan’s nuclear culture and its attitude towards risk. Japanese authorities exhibited a reluctance to evaluate serious risks, which may reflect a more general Japanese bias against open discussion of worst-case scenarios or contingency preparations, he added.


• Corporate and Nuclear Culture: Japan’s nuclear energy sector has had a tendency to be insular, elitist, and unwilling to take advice from experts outside the nuclear field, Hibbs explained. 

The March 11, 2011 accident at Japan’s Fukushima Daiichi Nuclear Power Station turned a spotlight onto nuclear safety in the United States., Commissioner George Apostolakis described actions the U.S. Nuclear Regulatory Commission (NRC) took following the accident and the broader regulatory implications of Fukushima for nuclear power plants in the United States.

NRC Actions after Fukushima:

• Systematic Response: Following the accident, the NRC promptly conducted inspections of U.S. plants, formed the Fukushima Near-Term Task Force to make recommendations, collected input from external stakeholders, and employed NRC senior management to review all recommendations, Apostolakis said.


• High Priority Actions: Apostolakis outlined the three major “high priority actions” the NRC is currently undergoing:
  
  
  • Orders: The NRC is issuing orders to nuclear licensees to protect equipment used for damage mitigation and to install reliable hardened vents and spent fuel pool instrumentation.
  
  
  • Request for Information: The commission is issuing a letter requesting information relevant to seismic and flood safety at existing nuclear plants.
  
  
  • Rulemaking: The NRC is initiating rulemaking to revise station blackout requirements and to strengthen and integrate emergency operating procedures and damage mitigation guidelines. 


• Remaining Actions: The commission will establish a plan for further actions this summer, Apostolakis added.

Regulatory Impact of Fukushima: 

• Existing Approach: Fundamental to the NRC’s approach is the concept of design basis accidents, a set of highly unlikely, postulated accidents that a facility must be designed and built to withstand, Apostolakis explained. In addition, the NRC employs a philosophy called “defense in depth,” which employs successive compensatory measures to prevent accidents or mitigate damage if a malfunction, accident, or naturally caused event occurs at a nuclear facility. A “patchwork” of additional regulations have been established for some beyond-design-basis accidents.


• Towards a New Framework: To build on existing measures in response to the March 2011 accident, the Fukushima Near-Term Task Force recommended that the commission establish a logical, systematic, and coherent regulatory framework for adequate protection that appropriately balances defense in depth and risk considerations, Apostolakis added. 


• Risk Management: Since the mid-1980s, Apostolakis explained, the NRC has been reviewing and authorizing improvements to technical specifications using probabilistic risk assessment. To supplement this methodology, a task force for the assessment of options for a more holistic risk-informed, performance-based regulatory approach was formed in February 2011. Its charter is to develop a strategic vision and options for adopting a more comprehensive regulatory approach for reactors, materials, waste, fuel cycle, and transportation that would continue to ensure the safe and secure use of nuclear material. The final report will be completed this spring, he added.


• Design Enhancement Category: Apostolakis recommended the NRC establish a design enhancement category of regulatory treatment for beyond-design-basis accidents. This category, he said, should use risk as the safety measure, be performance-based (including a provision for periodic updates), include consideration of costs, and be implemented on a site-specific basis.

The Fukushima accident has prompted the U.S. nuclear industry and the U.S. Nuclear Regulatory Commission (NRC) to improve accident management procedures, but questions about the adequacy of their approach have been raised. Three distinguished nuclear energy specialists—former NRC Chairman Richard Meserve, the Nuclear Energy Institute’s Marvin Fertel, and the Natural Resources Defense Council’s Christopher Paine—discussed the implications of Fukushima for nuclear energy in the United States. Carnegie’s James Acton moderated.

Enhancing Emergency Response 

• Deficiencies of Existing Regulations: After the September 11 attacks, NRC developed extensive guidelines to maintain adequate cooling of a plant’s nuclear reactor core and spent fuel pools in the event of fires and explosions, such as those that might be caused by a terrorist attack, explained Meserve. However, he noted that such guidelines were developed “in a security context.” He expressed concern that the equipment used to respond to a station blackout, such as back-up generators and water pumps “might not be stored in a way to withstand a range of events,” such as an earthquake.


• Industry Response: Fertel added that both the accident at Fukushima and the September 11 attacks convinced the U.S. nuclear industry of the importance of “flexibility and diversity of equipment” because operators could not predict what kinds of emergency contingencies would arise in the event of a terrorist attack or natural disaster. Although the NRC is developing rules for ensuring the safety of nuclear power plants in emergency situations, U.S. industry is already taking steps to improve emergency response capabilities, Fertel noted. He explained that the industry has been equipping plants with additional generators, hoses, and pumps, and planning for additional equipment to be brought onto a nuclear power plant from regional off-site facilities.


• An Alternative Approach: However, Paine was skeptical that “off the shelf” measures would ensure adequate cooling of nuclear material in a plant in the event of an emergency. He argued instead for constructing “in-plant solutions,” such as installing permanent magnet motors, which would allow cooling systems to function even if emergency generators fail.

Assessing Plant Safety

• Design Basis Review: The NRC’s Fukushima Near Term-Task Force has recommended that the design basis of all U.S. nuclear power plants should be reviewed in the near future  and then again once every 10 years. Fertel and Paine agreed that a design basis review would be valuable but argued that it should be repeated when new evidence becomes available, not according to a fixed timetable.


• Backfit rule: Under the “backfit rule,” the NRC performs a cost benefit analysis for proposed improvements to nuclear power plants that go beyond “adequate safety.” Paine argued that the NRC’s implementation of  the backfit rule was flawed since the consequences of all accidents were assumed to be small. Meserve defended this approach because evacuation plans would ensure that any accident would have only a small impact on human health.

The Fukushima accident continues to have significant repercussions on the future of nuclear energy worldwide. Nuclear liability expert Omer Brown, Japan Atomic Industry Forum President Takuya Hattori, and Federation of American Scientists President Charles Ferguson discussed how Fukushima will affect the Japan’s energy future, the nuclear liability regime, and the future of nuclear power in both established and emerging markets.

Japan’s Response to Fukushima

• Internalizing Lessons Learned: Hattori stated that, in his opinion, the Fukushima accident was the result of a lack of imagination about potential threats, institutional failures and inadequate management. He explained that Japan’s nuclear industry and regulatory establishment are dissecting information obtained from analysis of the Fukushima accident to better improve nuclear power plant design, nuclear safety culture, emergency preparedness, and public communication.


• Decreased Dependence on Nuclear Energy: Pre-Fukushima plans set the goal of Japan deriving 50 percent of its electricity from nuclear energy. Hattori stated that that vision is now “impossible” in light of the Japanese public’s mistrust of the nuclear industry. However, Hattori also predicted that Japan will not see a dramatic decline in the amount of electricity it derives from nuclear energy.


• Increased International Cooperation: Japan’s nuclear industry will look to expand international cooperation in nuclear safety to better apply the experience and innovations of other countries to improve safety at Japanese plants, Hattori added.

Trends in Key Countries

• Decreased Public Support Globally: Public opinion polls showed that support for nuclear power declined worldwide in the aftermath of Fukushima. Opposition grew in countries that already had a majority of people opposed to nuclear energy, while the margin of support decreased in countries where a majority of people were previously in favor of nuclear energy, Ferguson said.


• Scaling Back Plans: Germany and Switzerland are phasing out nuclear power while the French Socialist party is arguing that nuclear should play a smaller role in France’s overall energy mix, Ferguson added. 


• Relative Newcomers Forging Ahead: Although China has temporarily halted its construction of new nuclear power plants, it still plans to derive a significant fraction of its energy from nuclear plants, Ferguson noted. Meanwhile, South Korea is moving ahead with domestic nuclear expansion and South Korea’s state-owned nuclear vendor has set for itself an ambitious goal of capturing 20 percent of the nuclear power plant export market, and Jordan and Vietnam are still seeking to build their first nuclear power plants, he added.

Barriers to Further Nuclear Energy Expansion

• Loss of Public Trust: A loss of public trust remains a key barrier to the expansion of nuclear power, particularly in democratic countries, noted Hattori and Ferguson. 


• High Cost of Nuclear Construction: The economics of nuclear power require a significant amount of up-front investment, even though the cost of electricity produced once a nuclear power plant is operational is low, Ferguson noted. As a result, the availability of government loan guarantees and economic incentives will be a key determinant of whether new nuclear construction proceeds.


• Patchwork Liability Regime: Currently, there is no worldwide nuclear liability regime to facilitate and expedite the handling of compensation claims in the event of a nuclear accident. Brown noted that although a number of legal instruments to harmonize liability and compensation measures exist, notably the international Convention on Supplementary Compensation, states have resisted taking the steps to create a global liability regime.