MOX fuel rods used in Japanese Nuclear Reactor present multiple dangers

Fukushima Daiichi Nuclear Power Plant Okuma Photo: DigitalGlobe’s Firstwatch Imagery Report
Fukushima Daiichi Nuclear Power Plant Okuma Photo: DigitalGlobe’s Firstwatch Imagery Report

The mixed oxide fuel rods used in the compromised number three reactor at the Fukushima Daiichi complex contain enough plutonium to threaten public health with the possibility of inhalation of airborne plutonium particles. The compromised fuel rods supplied to the Tokyo Electric Company by the French firm AREVA.

Plutonium is at its most dangerous when it is inhaled and gets into the lungs. The effect on the human body is to vastly increase the chance of developing fatal cancers.

Masashi Goto, a reactor researcher and designer for Toshiba, told the Foreign Correspondents Club in Toyko the mixed oxide (MOX) fuel used in unit 3 of the Fukushima Daiichi nuclear facility uses plutonium, which is “much more toxic than the fuel used in the other reactors.”

Goto said that the MOX also has a lower melting point than the other reactor fuels. The Fukushima facility began using MOX fuel in September 2010, becoming the third plant in Japan to do so, according to MOX supplier AREVA.

Part of the process of making MOX fuel is to grind plutonium into a fine power before it is robotically inserted into fuel rods. Experts agree these tiny plutonium particles once airborne are extremely dangerous to human health.

Workers observing material at the Shaw-AREVA Mixed-Oxide Plant at the Savannah River Site in South Carolina. Photo: Shaw-Areva
Workers observing material at the Shaw-AREVA Mixed-Oxide Plant at the Savannah River Site in South Carolina. Photo: Shaw-Areva
One of the unique characteristics of mixed oxide fuel is that relatively little of the plutonium in the fuel rods is used up in the fuel cycle in a reactor. “When the plutonium in the fuel rods goes into a reactor for commercial power, a very little of it is going to be consumed. I don’t know what percentage, maybe half percentage or something like that, but it’s going to generate an extraordinary amount of contamination throughout the fuel rods…,” says William Lawler, an expert on radioactive waste.

The damaged number three reactor was undergoing its first fuel cycle using MOX at Daiichi. MOX fuel was first used in a thermal reactor in 1963, but it did not come into commercial use until the 1980s. One reason proponents of MOX reactor fuel support its use is because, once the fuel is burned in a reactor, it is so hot that terrorists would not be able to steal a fuel assembly.

Lawless, who worked at the DOE’s Savannah River Site and first exposed massive contamination there in the early 1980s, says MOX being used as a way of controlling weapons proliferation is a myth: “You will decrease the amount of plutonium minutely but you will increase the amount of waste inside the fuel rod greatly into something that is very contaminated for a long period of time and they think is that it would be too deadly to handle for a terrorist…This is not necessarily following the best scientific plan or the best engineering decision; this is more a political decision, the MOX.”

Robert Alvarez, a Fellow with the Institute of Policy Studies and former aide to the Secretary of Energy and former Senator John Glenn, explains that many in the nuclear weapons community see leftover plutonium from nuclear weapons as a resource that should not be squandered instead of the very dangerous substance that it is. Prior to the plans for the MOX plant for weapons-grade plutonium at the Savannah River Site, the excess plutonium was to be locked into large, molten glass logs and stored in a repository.

“The U.S. amassed 111.4 kg of plutonium from its nuclear arsenal; all the countries that are reprocessing have amassed 250 kg of plutonium with no place to go. The plutonium that has been used for MOX by the French is a very, very small fraction, and they have discovered that they can only use it once because this spent fuel is so hot and the cost of disposing of this spent fuel goes dramatically up compared to the other stuff. ..The French may be recycling 12 percent. The rest is sailing into burials as de facto radioactive waste. So there are dreams and there are realities. The reality is that this costs a lot of money. It is not working…,” Alvarez says.

The United States, Japan, and Europe do not have permanent repositories for high-level nuclear waste.  That is why so many used fuel elements were being stored at the Japanese reactor site.

Six months before the Japanese earthquake, Alvarez told the idea of MOX fuel does not add up anymore. “They are largely overtaken by events and the system is just ill-equipped, unable, structurally fixed into decisions that don’t make much sense anymore…The only prospect that you have here, which you should not dismiss, is that it has the potential of rendering a large amount of plutonium into a form that makes it extremely useful to reuse. And that was the original intent of the MOX program. It was not meant to be a way to generate energy and make money. Because the money is losing, this plutonium has negative value. They probably know this might not work and cause problems to reactors, and they might shut down reactors and lose money.”

The National Nuclear Security Administration, an autonomous agency inside the Department of Energy, is 85 percent of the DOE budget. It has partnered with an American firm, Shaw, and AREVA in France to build a MOX plant at the Savannah River Site to process weapons grade plutonium into MOX fuel. This $5 billion plant, still under construction, has been plagued with problems. A commercial partners, Duke Power, dropped out of the project after a test of a fuel array made by AREVA from weapons grade plutonian was stopped in the middle of a fuel cycle at a Duke Power reactor at Catawba, North Carolina.

Mixed oxide fuel is a combination of finely ground up plutonium particles and uranium oxide fabricated into fuel rods at an AREVA subsidiary in La Hague, France.  The fuel is made from reprocessing old reactor fuel. Reprocessing was abandoned by the United States in the 1970s because of the dangers of weapons proliferation.

The CIA has reported that Japan’s nuclear power program was not limited to the peaceful production of electrical power. The program had its roots in a secret weapons program that caused the CIA to conclude as far back as 1964 that Japan could assemble within months a nuclear weapon.

Because of the Japanese public’s fear of nuclear weapons, the various subsequent Japanese governments have kept the program secret and have repeatedly denied its existence when news organizations made inquiries.