Would U.S. Nuclear Experts Be Better Able to Avert a Meltdown Than the Japanese Experts Were?

Ask a Scientist - October 2011

L. Larsen of Novato, CA, asks: “The U.S. news media seem to have dropped the subject of the Fukushima Daiichi Nuclear Power Station. What is its status today? Is it true that three nuclear cores underwent meltdowns? Will ocean currents bring radioactive material to the West Coast of the United States or to other shores? And, if a similar accident happened here, would U.S. nuclear experts be better able to avert a meltdown than the Japanese experts were?" She is answered by Dave Lochbaum, nuclear engineer and Director of the UCS Nuclear Safety Project.

Today, nearly seven months since the disastrous earthquake and tsunami in Japan, plant workers at the Fukushima Daiichi Power Station are still seeking to return three of the plant’s six reactors to a stable condition. You are correct that three units—Reactors 1, 2, and 3—experienced meltdowns in the days following the earthquake and tsunami. Reactor 4 had been de-fueled at the time of the earthquake while Reactors 5 and 6 were in cold shutdown for planned maintenance.

The plant recently passed several important milestones in the cleanup process. First of all, workers succeeded in implementing closed-loop cooling for all three of these reactors in which cooling water is pumped in and reused to cool the plants’ nuclear fuel. Prior to this, operators had to pour water on the fuel from helicopters or fire trucks in a process known in the industry as “feed and bleed.”

While plant operators worked to contain much of the wastewater contaminated with radiation that escaped from the plant during this process, a great deal also leached into the ground or into the ocean. The plant operators have now installed systems to treat the tens of thousands of tons of this contaminated wastewater that they had captured and have treated roughly half of it to a level where it can be legally discharged to the ocean or even reused in some applications. This water treatment facility has been in operation for almost two months now.

Equally important, cleanup crews have now succeeded in erecting a scaffolding over units 1, 3, and 4 that will eventually support a fabric cover to contain airborne radiation leaking from these reactors. All of these reactors experienced structural damage to their containment buildings. Because of earthquake damage, workers could not add new and heavy cement on top of these buildings’ already shaky foundations, so the fabric will serve as a barrier, allowing operators to treat the plants’ airborne radiation with filters. Fans will pull air from the space inside the fabric containment into these filters so that will allow the containment area to operate under low pressure, which will also keep radiation from escaping. 

In other words, plant operators are making some significant progress. Perhaps the biggest challenge they face is what they can’t control. The region has experienced a series of aftershocks and another significant earthquake could cause a further release of radioactivity.

As for the radiation that has already been released, Japanese officials created a 20-kilometer exclusion zone and it has received a good deal of surface contamination from radioactive fallout from the plant. The Japanese government faces a business decision about whether to keep people away from the area for many, many years to come or go to the great effort and expense of remediating the area by stripping away all surface materials and soils, placing them in a licensed landfill. One thing we have learned the hard way: the longer they wait, the further down the radiation will go. Trees and other plants, for instance, carry the material further into the ground through their roots.

As for radioactive materials dispersed into the ocean, you should rest assured that the dilution effect reduces the hazard to a negligible level way before it reaches even the beaches of Hawaii. On the other hand, however, concentration of radiation can occur through the marine food chain. Kelp, for instance, tend to concentrate radiation and get eaten by many species of fish we consume. Increased radiation monitoring of fish will be necessary and, to some extent, has already begun.

Finally, you ask whether U.S. plant officials would have reacted more effectively to the disaster. Unfortunately, the answer is no. The types of boiling water reactors at the Fukushima Daiichi Power Station were designed by General Electric which formulated the accident response plan followed by the Japanese plant operators. Everyone in the world operating these types of reactors would have followed the same response plan. That means we have some important work to do to learn from this incident and make our reactors safer in the event of a similarly devastating challenge.

As I testified before Congress on behalf of the Union of Concerned Scientists, we think there are three essential lessons that can make our reactors in the United States less vulnerable to this kind of an event in the future: first, we believe spent fuel should be moved from cooling pools to dry cask storage. This is, in our view, a “no-brainer” but we still haven’t done it. Spent fuel in dry cask storage significantly reduces the threat of radioactive material being released by fire or meltdown.
Second, nuclear reactors in Japan at the time of this accident were required to be able to operate for eight hours on battery power. Clearly, this was insufficient in this kind of scenario. Here in the United States, most of our reactors can operate for only four hours on battery power. We have urged that the issue of backup power after a large-scale disaster be studied on a site by site basis, with each plant demonstrating how they could meet their power needs during that crucial period.

Finally, the disaster in Japan pointed out the fact that plant owners in the United States are not required to teach emergency procedures for such an event. They should be. I personally used to teach emergency procedures when I worked at Nuclear Regulatory Commission and I am keenly aware that, while the U.S. government requires operators to learn emergency procedures to handle things like fires and broken pipes, training for severe accident scenarios occurs on a voluntary basis, if at all at U.S. nuclear reactors. As unlikely as such a disaster might be, the experience at the Fukushima Daiichi plant teaches us that we absolutely need to be prepared to face it should such a bad day ever arrive.

Safety I.O.U.s won’t help anybody. We can’t be confident of having learned the lesson from the disaster in Japan until all of these fixes have been made.  

David Lochbaum is one of the nation's top independent experts on nuclear power. At UCS, he monitors safety issues at the nation's nuclear power plants, raises concerns with the Nuclear Regulatory Commission, and responds to breaking events, such as the 2011 nuclear reactor crisis in Japan. Mr. Lochbaum is a nuclear engineer by training and worked in nuclear power plants for 17 years. In 1992, he and a colleague identified a safety problem in a plant where they were working, but were ignored when they raised the issue with the plant manager, the utility, and the Nuclear Regulatory Commission. They decided to go to Congress, and the problem was eventually corrected at the original plant and at plants across the country. Concerned about nuclear safety and frustrated with the NRC's complacency, Mr. Lochbaum joined UCS in 1996. He spent a year as an instructor at the NRC Training Center in 2009-2010.

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