VIENNA ― Nuclear power has become safer since the devastating accident one year ago at Fukushima, Japan. It will become safer still in the coming years, provided that governments, plant operators, and regulators do not drop their guard.

The accident at Fukushima resulted from an earthquake and tsunami of unprecedented severity. But, as the Japanese authorities have acknowledged, human and organizational failings played an important part, too.

For example, Japan’s nuclear regulatory authority was not sufficiently independent, and oversight of the plant operator, TEPCO, was weak. At the Fukushima site, the backup power supply, essential for maintaining vital safety functions such as cooling the reactors and spent fuel rods, was not properly protected. Training to respond to severe accidents was inadequate. There was a lack of integrated emergency-response capability at the site and nationally.

Human and organizational failings are not unique to Japan. Fukushima was a wake-up call for all countries that use nuclear power. It prompted serious soul-searching and recognition that safety can never be taken for granted anywhere. Key causes of the accident have been identified.

Indeed, governments, regulators, and plant operators around the world have begun learning the right lessons. A robust international nuclear safety action plan is being implemented. As a result, the likelihood of another disaster on the scale of Fukushima has been reduced.

What, exactly, has changed? Perhaps most importantly, the worst-case assumptions for safety planning have been radically revised. At Fukushima, the reactors withstood a magnitude 9.0 earthquake ― far more powerful than they were designed to tolerate. But the plant was not designed to withstand the 14-meter-high tsunami waves that swept over its protective sea wall less than an hour later.

In the aftermath of Fukushima, defenses against multiple severe natural disasters, including earthquakes and tsunamis, are being strengthened at nuclear facilities all over the world. Measures are being taken to improve preparedness for prolonged power outages, protect backup power sources, and ensure the availability of water for cooling even under severe accident conditions.

Global nuclear safety standards are being reviewed. National and international emergency-response capabilities are being upgraded. Plant operators and national regulators are being scrutinized more critically. Countries are opening their plants to more ― and more thorough ― international safety reviews.

Despite the accident, global use of nuclear power looks set to grow steadily in the next 20 years, although at a slower rate than previously forecast. The reasons for this have not changed: rising demand for energy, alongside concerns about climate change, volatile fossil-fuel prices, and the security of energy supplies. It will be difficult for the world to achieve the twin goals of ensuring sustainable energy supplies and curbing greenhouse gases unless nuclear power remains an important part of the global energy mix.

The International Atomic Energy Agency expects at least 90 additional nuclear-power reactors to join the 437 now in operation globally by 2030. Although some countries abandoned or scaled back their nuclear energy plans after Fukushima, major users of nuclear power, such as China, India, and Russia, are going forward with ambitious expansion plans. Many other countries, mainly in the developing world, are considering introducing nuclear power.

Nuclear safety is of the utmost importance to both established users and newcomers. It matters to countries that have decided to phase out nuclear power, because their plants will continue to operate for decades and will need to be decommissioned, with nuclear waste stored safely. And it matters to countries that are firmly opposed to nuclear power, as many of them have neighbors with nuclear-power plants.

Countries planning new nuclear-power programs must recognize that achieving their goals is a challenging, long-term undertaking. They need to invest considerable time and money in training scientists and engineers, establishing genuinely independent, well-funded regulators, and putting in place the necessary technical infrastructure. Some countries still have shortcomings in this regard.

Nonetheless, contrary to popular perception, nuclear power has a good overall safety record. New reactors being built today incorporate significantly enhanced safety features, both active and passive, compared to the Fukushima generation of reactors. But, in order to regain and maintain public confidence, governments, regulators, and operators must be transparent about the benefits and risks of nuclear power ― and honest when things go wrong.

The fact that an accident such as Fukushima was possible in Japan, one of the world’s most advanced industrial countries, is a reminder that, when it comes to nuclear safety, nothing can be taken for granted. Complacency can be deadly. The safety improvements seen in the past 12 months can only be a start. We must not slip back into a “business as usual” approach as Fukushima recedes from memory.

By Yukiya Amano

Yukiya Amano is director general of the International Atomic Energy Agency. ― Ed.

(Project Syndicate)