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Atomkraftwerk Oi Reaktor 4 in der Präfektur Fukui Japan
Image: Reuters

'Better prepared' nuclear plants

Interview: Gabriel Domínguez
March 9, 2015

Charles Casto advised the Japanese authorities on their handling of the Fukushima crisis on behalf of the US government. Four years on, the nuclear expert talks to DW about the lessons Japan has drawn from the disaster.


Four years ago, on March 11, 2011, Japan faced the combined forces of nature and physics. A powerful earthquake and the tsunami that followed not only devastated the region surrounding the Fukushima Daichi atomic power plant, but also led to a nuclear disaster.

The ensuing social and environmental crisis would turn the global focus on the risks associated with nuclear energy. Before the disaster struck, Japan used to rely on nuclear power for 30 percent of its electricity needs. In the wake of the catastrophe, however, Japan halted operations at all 48 of its reactors. The disaster's impact on nuclear power generation was also felt beyond the nation's borders, with Germany announcing plans to denuclearize the country by 2022.

Nevertheless, the government of Japan's Prime Minister Shinzo Abe wants to reopen the reactors closed in the aftermath of the Fukushima accident, and there are even plans to build new ones in the future. Several nuclear plants are expected to restart this year after meeting stricter rules introduced after the incident.

Against this backdrop, Charles Casto, former leader of US Nuclear Regulatory Commission (NRC) efforts in Japan during the Fukushima nuclear accident in 2011, says that Japanese nuclear plants now better prepared than before to withstand another such natural disaster.

But although he believes that technically many of the reactors are able to reopen, it does not mean that they should restart without first obtaining public and local government support, the nuclear expert stresses.

Dr. Charles A. Casto
Casto: 'A greater crisis was averted through the dedicated effort of the Japanese operators at Daiichi'Image: privat

DW: What exactly was your role during the nuclear crisis at Fukushima Daiichi?

Charles Casto: I was assigned as the executive team leader for the US Nuclear Regulatory Commission. I led the US government response for the Fukushima nuclear event. Traveling to Japan just a few days into the accident, our team ranged from 15-20 people at any given time. Our roles were to provide Ambassador John Roos with advice on the protection of American citizens in Japan.

We also provided technical support and other resources to the Japanese government. Our team coordinated with the Japanese nuclear regulatory agency, at the time called "NISA" to work with them solving serious problems that were facing the utility in response to the accident.

As the months progressed we worked with the Japanese to find methods to allow the reactors to reach "cold shutdown," which is a condition where the reactors are stable and minimum risk to the public exists.

That cold shutdown was reached around December 20, 2011, about 10 months after the accident. I remained in Japan several months afterward working on establishing conditions to allow restart of the 45 plus idle reactors in the Japanese nuclear fleet.

What were the main challenges in those key first few days after the tsunami?

The magnitude 9.0 earthquake that struck Japan was felt as far away as Antarctica. The resulting tsunami created was enormous, and ocean waves as high as four- and five-storey buildings overwhelmed villages up and down the Sendai Coast. While tens of thousands of lives were lost, roads, bridges and other critical physical infrastructure were destroyed. Thousands of people still remain unaccounted.

Symbolbild Japan Atomkraft Protest Demonstration
There have been many demonstrations against restarting nuclear power plants in JapanImage: Reuters

Soon Fukushima Daiichi and other nuclear power plants were left without vital water and power supplies. Without their lifeblood – electricity - the reactors and spent fuel pools would meltdown. It knocked Japan to its knees. Most of the emergency equipment, facilities and people in the area were lost to the earthquake and tsunami. The situation was more than desperate.

There were radiation alarms sounding, darkness in and around the plant, explosions and tremendous structural damage and the potential for more great aftershocks and tsunamis. With such extensive damage there was little hope of restoring water and power.

Meanwhile, in a similar fate a few kilometers South at the Fukushima Daini nuclear plant, engineers were working to install temporary high voltage cable to keep the four reactors there from melting down. The world was unaware of the heroic efforts of 200 people who installed over nine kilometers of large electrical cable under terrible conditions in just a few hours averting another huge nuclear disaster.

There were significant geopolitical issues involved in ocean contamination, plume of radiation reaching across the Pacific and passenger travel to and from Japan. We remained very concerned about more earthquakes, tsunamis, further explosions and releases from the facility. For the first time, this was a multiple reactor accident and it was the first "web-streamed" nuclear meltdown so the fear created reached around the world.

There was a loss of many first responders which complicated the disaster immensely. Then, the accident at Fukushima caused a plume of radiation, an unseen hazard that added great fear to the Japanese people. While many people talk about the triple crisis of earthquake, tsunami and nuclear events, there was also a huge social crisis. We worked to limit the consequences and fear caused by the nuclear event.

In the end, was an even worse outcome averted? How was this achieved? Please explain.

Through the dedicated effort of the Japanese operators at Daiichi, a greater crisis was averted. Operators in the control room and emergency center took heroic actions to limit the damage to the facility.

Perhaps a quicker response from outside of the facility would have limited some of the damage; nevertheless, with the force of the tsunami it was likely that some or all of the reactors would have extensive damage.

The operators, by venting off the excessive steam pressure and keeping water injection going, certainly limited the size of the radioactive plume. Under horrific physical and emotional challenges, the operators did what they could to stave off a complete disaster that could affect a greater area of Japan and release significant amount of radioactive to the ocean and air.

With little equipment remaining and no reason to stay in the facility, the operators remained dedicated to the protection of the people and environment. The US, for its part, dispatched nuclear specialists and other assistance to Japan. The experts provided support in controlling the reactors and spent fuel pools.

What do you make of both TEPCO's and the government's initial handling of the crisis and their information policy?

Clearly there were mistakes early on during the crisis. That is to be expected in a disaster of this magnitude. The biggest challenge was the lack of technical information for the reactors. The earthquake and tsunami had destroyed much of the facility and its instrumentation rendering the operators blind. So the ability to gather information and share that information was very limited.

There were breakdowns in their evacuation process caused by a breakdown in the communications of radioactive plume information. Power supply failures and inability of officials to understand the information greatly complicated the evacuation process.

About 120,000 people who lived in the vicinity of the Fukushima plant have not been able to return home due to radioactive contamination. How would you describe the nuclear fallout's effects on the surrounding communities?

The disaster caused an economic impact amounting to over 2.5 percent of Japan's economic output. While tens of thousands lost their lives, thousands of families still remain displaced. For me, the emotional impact of this crisis happened on my first trip through the evacuated zone. As we drove through the zone the damage took our breath, with homes evacuated for miles and buildings completely destroyed.

As we approached Fukushima we could see the carcasses of the reactor buildings. The damage was more than I could fathom. I could not believe that the force of water could create that much damage. Steel beams twisted like paper, huge storage tanks dislodged, the damage was unfathomable. My conclusion was that we, the nuclear industry, can never let this happen again.

I've visited the evacuation several times over the past four years. Recently I visited the evacuated zone again to meet with local officials, businesspeople, cleanup workers, farmers and citizens. Their spirit is wonderful. They are working together to restore their communities, and day-by-day their work is paying off. More and more people are returning to the area.

Japan Erdbeben und Tsunami Fukushima Fähre auf dem Dach in Otsuchi Luftaufnahme
The earthquake and tsunami devastated the region surrounding the nuclear plantImage: The Yomiuri Shimbun, Motoki Nakashima/dapd

Four years on, what lessons should Japan learn from this disaster and have any of them been realized?

There are many lessons learned; however, one of the biggest lessons is that we must have a fundamental belief that an accident can happen. If you do not believe that an accident can happen, you will not prepare adequately. Second, with regard to crisis response, we learn that responders must act comprehensively; that the speed of the response must at least match the speed of the event; and that the response must be smart.

Being smart means that politicians, government officials and other leaders must recognize their proper roles and responsibilities and solutions must be anchored in facts. From a policy perspective, we learn that there must be a proper balance between the responsibilities of the government and the nuclear utilities. The nuclear utilities must be responsible, capable, and accountable for safe operation under all conditions.

In your view, are Japanese nuclear plants now better prepared than before to withstand another such natural disaster?

Yes, very much better prepared. I have personally reviewed the technical assessments made by the Japanese utilities and I have witnessed operators use the new emergency equipment installed at several reactors to provide backup power and water to the reactor should an extreme event occur again.

Symbolbild Anti-Atomkraft-Demo
Germany announced plans to denuclearize the country by 2022 in the aftermath of the Fukushima disasterImage: dapd

That said, because I believe that technically many of the reactors are able to restart that does not mean that they should restart without first obtaining public and local government support.

The Fukushima event was both a natural and technological disaster. It was also a social and policy crisis. I believe that most of the Japanese utilities and their government have addressed the natural and technological challenges. What remains to be accomplished is to restore the public trust and to resolve several important policy issues. Most importantly the government must resolve the acceptable level of risk that the public is willing to accept for restoring operation of their nuclear power fleet.

Dr. Charles Casto led the integrated US Government and Nuclear Regulatory Commission (NRC) efforts in Japan during the Fukushima nuclear accident in 2011. He is currently president of Casto Group Consulting LLC.

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