Aftermath of Fukushima: Avoiding another major nuclear disaster

Highlights

• Japan’s nuclear power laws encouraged a mindset of negligence toward safety.

• Many reactors built at one site, so one accident could impact many reactors.

• Government and industry must devise financial and culture-based safety incentives.

• Set asides for accidents that impact profitability is key to safety culture.

Abstract

Japan’s laws to promote nuclear power, including the Dengen Sampo (the Three Electric Power Laws), have accelerated nuclear reactor construction via subsidies, grants, and other incentives. These laws also have had the perverse effects of discouraging promotion of safety as the highest priority, with consequences that can be seen in the Fukushima nuclear disaster. If the government decides to restart a portion of the reactor fleet, experience indicates that another serious nuclear accident could be expected again. Accidents, in effect, represent a recurring cost which should be built into business plans. Although improvements in reliability and safety will certainly be made, legislation alone cannot guarantee that these actions will create a culture of safety. Inevitably, the complex systems associated with nuclear reactors and the overwhelming influence of corporate officers who are focused on cutting costs in the near-term will make safety improvement an uphill battle. These factors are symptomatic of a worldwide nuclear industry that views safety as a cost to be managed. Unless the industry is incentivized to consider safety improvements as a source of greater profits in the long-term, the industry will continue to have a mindset of negligence toward safety.

Introduction

On 11 March 2011, a massive earthquake struck the eastern region of Japan, the most powerful earthquake ever recorded there. The earthquake triggered a 15-meter tsunami that over-topped the Fukushima Daiichi plant’s 5.7-meter seawall (see Fig. 1). Worst of all, the nuclear complex suffered a total station blackout because primary power from the regional grid was off-line and most of the plant’s back-up diesel generators, which were located below sea-level, were flooded by the tsunami. The tsunami also damaged the plant’s electrical distribution system. Without power, cooling pumps stopped functioning, leading to a catastrophic build-up of decay heat in the reactors and the meltdown of three reactor cores. The extreme heat and high-pressure steam generated by the core meltdowns triggered several hydrogen-air chemical explosions, resulting in the release of radioactive material into the environment (IEA, 2014, National Diet of Japan (National Diet), 2012).

The Fukushima Daiichi nuclear disaster brought long-lasting damage to Japan. Radioactive cesium contaminated 11,580 square miles (about 30,000 km²) of the land surface of Japan, according to the Japanese Science Ministry (Asahi Shimbun, 2011). An area of about 130 square miles (337 km²) is now designated as unsafe for human habitation (the area colored in brown in Fig. 2). This area represents almost one percent of Japan’s scarce arable land (which is about 17,274 square miles (44,739 km²)) and is equivalent to the combined land area of the boroughs of Manhattan, the Bronx and Brooklyn in New York City.¹ Restrictions likely will remain in effect for generations because the primary contaminant, Cesium-137, has a half-life of 30 years, requiring10 half-lives to pass for most radionuclides to disappear (U.S. NRC, 1989).

This paper assesses how Japan’s legislative framework for governing nuclear power contributed to the root cause for the disaster, such as accelerating reactor construction rates without encouraging enhancements to safety. It analyzes how limitations on corporate liability disincentivized power plant owners from investing in safer designs and practices. The paper considers how the expected frequency of future accidents, along with estimates of accident costs could provide a useful metric for evaluating safety improvements. It proposes that power companies set aside funds to cover future accident costs and suggests that Japan (as well as other governments with nuclear power programs) adjust set-aside requirements based on assessments of corporate dedication to safety, and thereby incentivize companies to establish a zero accident culture as a key business goal.