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Averting Meltdown

​THE COLD WAR IS LONG OVER, and the era of Mutual Assured Destruction is a distant memory. But political and social crises in Ukraine, and Russia’s aspirations for that former Soviet republic and beyond, have stirred the ashes of a nuclear standoff between superpowers. And after decades of expansion of nuclear power plants across the globe and more and more countries obtaining nuclear capabilities, serious concerns about nuclear safety and security remain among both regulators and the general public.

Safety. Tsunamis left the realm of Hollywood disaster films and squarely entered real life for much of the world when an earthquake rocked Japan in March 2011. A tsunami is a series of ocean waves that create surges of water, sometimes reaching heights of more than 100 feet. These surging walls of water can reach speeds of almost 500 miles an hour, crossing the Pacific in less than a day and losing little energy in the process.

The 2011 earthquake that struck Japan set off a tsunami whose devastation was catastrophic. To make matters worse, the tsunami also flooded the Fukushima Daiichi nuclear station, destroying its power supplies and emergency equipment, as the plant was built to withstand waves only 3.1 meters (about 10.2 feet) high.

With the power knocked out and emergency equipment unavailable, the plant’s operators were unable to cool the station’s reactors. Nuclear fuel was exposed, creating great heat and causing a meltdown. Ultimately, this caused an explosion at the plant and the release of radioactive material into the atmosphere. It was the worst nuclear power disaster since the Chernobyl accident in the 1980s, and it caused massive evacuations from the northern part of Japan.

Because of the dangers posed by nuclear power, regulators and the general public have questioned the safety and security of nuclear plants around the world. In an effort to evaluate nuclear reactor safety internationally, U.S. Sen. Tom Carper (D-DE) requested that the Government Accountability Office (GAO) research the issue and present its findings to Congress. “Nuclear energy continues to provide a clean, climate-friendly energy option for the world,” said Carper, who is also the chairman of the Senate Environment and Public Works Subcommittee on Transportation and Infrastructure. “However…a nuclear accident anywhere is an accident everywhere,” Carper added.

The GAO’s report examines the regulatory bodies of 16 countries—13 that operate 78 percent of the world’s nuclear power reactors and three that have an interest in developing reactors in the future. The agency also examined the development of new requirements, systems, and steps that international regulators have taken to promote nuclear safety worldwide over the last three years.

During the Fukushima incident, the loss of various emergency equipment prevented operators from cooling the reactors, the report says. This ultimately led to the fuel melting and to hydrogen building up and exploding, which destroyed three reactor containment structures and released radioactivity into the environment.

To combat this in the future, new regulatory requirements have been issued worldwide for emergency equipment. Some nations’ new requirements focus on having access to portable power generated vehicles and batteries, while others also require on-site storage of that equipment.

In the United States, the Nuclear Regulatory Commission (NRC) has issued an order to address operators’ capabilities to move water to maintain, or restore, reactor core cooling. According to the GAO’s report, the order requires these capabilities to be maintained even if power is lost, along with requirements for emergency back-up power supplies.

Moreover, all but one of the 13 nuclear regulatory bodies in the GAO review have issued additional requirements for control systems to prevent hydrogen from building up and exploding. Some of the countries are also studying new options for hydrogen detection, monitoring, and removal.

In addition, 11 of the 13 regulatory bodies have issued new requirements—or are studying options—for filtered venting systems. These new systems would minimize the release of radioactive materials into the environment in the event of an accident.

In the United States, the NRC is in the process of evaluating support for a rule on filtering. The commission voted to create a rulemaking proposal requiring the installation of filtered venting systems at boiling water reactors similar to those at Fukushima Daiichi. The final deadline for the rule is set for 2017.

Many nations have also sought to automate the process of transmitting critical data about nuclear reactors to their respective regulatory bodies. This would allow critical information on such practices as radiation monitoring to be transmitted directly to regulators to keep them informed.

The United States and five of the 13 countries evaluated by the GAO, including Belgium and Canada, have already established some form of an automated system for collecting and transmitting critical data. However, the U.S. system, Emergency Response Data System (ERDS), and other nations’ systems are not designed to operate under severe emergency conditions, such as situations when off-site power is not operational.

The GAO has recommended that the United States upgrade its system so it can transmit data during an emergency scenario. However, the NRC has not decided how it will develop such a system. The GAO has cautioned that delaying its decision may cause the system not to function when needed most: during a severe accident. The NRC plans to respond to Congress and the GAO about its plans for the ERDS recommendation within the 60-day window the agency was granted, says Scott Burnell, a spokesman for the GAO.

With the exception of Vietnam, all countries also conducted safety inspections after the nuclear disaster at Fukushima. Some of these inspections included stress tests in which extreme conditions were simulated to help operators identify vulnerabilities at their plants.

For example, at the Belgian Doel nuclear power plant, testers combined a severe storm with an unfavorable wind direction, which together could breach the embankment that protects the plant from flooding. The plant’s operator used the scenario to analyze the consequences of a breach; based on the results of the stress test, the Doel plant is proposing to reinforce the top of the embankment with concrete tiles to help prevent flooding. The plant also learned what it was doing well, such as protecting its emergency equipment.

The NRC in the United States did not require plants to conduct stress tests. Instead, nuclear power plant operators were required to complete detailed inspections, referred to as walkdowns, in which all safety features are checked to ensure they are operating properly. Operators are also required to submit reports to the NRC for review.

The NRC decided to conduct walkdowns, instead of stress tests, as part of a reevaluation effort to increase safety at plants that are vulnerable to earthquakes and floods. This reevaluation effort was initiated after the NRC’s Near-Term Task Force concluded that U.S. nuclear power plants could continue to operate safely because of their “robust designs” and portable resources that were developed after 9-11. These resources are sometimes referred to as B5b measures and supplement installed safety systems after a severe natural or manmade event, Burnell explains.

One positive item in the GAO’s report is that nuclear regulatory bodies in the 16 countries surveyed have taken steps to strengthen nuclear safety during the past three years. “Countries are taking steps with an increased focus on considering previously unimagined accident scenarios, such as those affecting multiple reactors within a given power plant,” the report stated.

Physical security. The 2014 Nuclear Security Summit, a gathering of global leaders in The Hague held in March, also focused on efforts that the international community has made to secure nuclear arms and nuclear power plants across the globe from threats and smugglers. President Barack Obama attended the summit as part of a broader tour through Europe during the spring, and he spoke about the progress that has been made in preventing smugglers and terrorists from gaining access to nuclear materials.

“Dozens of nations have boosted security at their nuclear storage sites, or built their own countersmuggling teams, or created new centers to improve nuclear security and training,” Obama said. “The IAEA [International Atomic Energy Agency] is now stronger, and more countries have ratified the treaties and international partnerships at the heart of our efforts. So we’ve seen a fundamental shift in our approach to nuclear security.”

As part of the renewed effort, 58 world leaders pledged to prevent terrorists from getting access to nuclear material. More specifically, the United States and 34 other countries agreed at the summit in the Hague to strengthen nuclear security implementation. Efforts to improve physical security include contributing to the development of IAEA nuclear security guidance documents; developing and enhancing cybersecurity measures concerning nuclear facilities; maintaining effective emergency and contingency preparedness, response, and mitigation capabilities; and promoting nuclear security culture for management and personnel involved with nuclear security.

Additionally, at the nuclear summit the United States committed to enhancing the security of the Maritime Supply Chain Gift Basket. The gift basket focuses on the maritime smuggling pathway and encourages partner countries to increase their involvement in securing that pathway. As part of this effort, the states supporting the gift basket are seeking to maintain effective radiation detection systems and response procedures at all of their large container seaports. They’re also being encouraged to help other states develop their own radiation detection capabilities.

Along with the gift basket’s measures, the IAEA, the European Union, and multiple other countries are also working to equip their own seaports and other border sites with radiation detection systems. These systems have been responsible for the detection of various nuclear and radiological materials that were not under regulatory control, in countries such as Georgia and Moldova.

“In several instances, these systems have been involved in the detection of the smuggling of nuclear materials that could be used for a weapon,” the White House said. “These cases help to underscore the importance of radiation detection systems at key international checkpoints.”

The United States is fulfilling its role in the effort by working with 20 countries to enhance the ability to detect, interdict, and prosecute nuclear smugglers. As of press time, 260 sites and ports had been equipped with radiation detection systems, and 41 mobile radiation detection devices had been deployed to internal checkpoints in 15 partner countries.

The United States has taken additional steps, such as working to increase security at 218 buildings in five countries storing nuclear materials by implementing new physical security upgrades. It’s also taken the step of introducing new cyber regulations to protect nuclear power plants.

However, speaking at the summit, Obama said there is more work that needs to be done by the United States and its partners around the globe. “I believe this is essential to the security of the entire world, and given the catastrophic consequences of even a single attack, we cannot be complacent,” he said.