MOX Utilization Approach Promises Big Dividends

FROM THE OUTSET OF THE nation's efforts to develop nuclear energy for peaceful purposes in the late 1950s, the Atomic Energy Commission of Japan favored a program based on the utility of plutonium.

Why? Because uranium fuel can be recycled more efficiently if plutonium—which is formed as a by-product when uranium is "burned"—is also extracted during the reprocessing. By recycling both the unburnt uranium and the newly created plutonium and reusing the two as fuel for fast-breeder reactors (FBR), the result can be a manyfold boost in uranium-use efficiency.

Still, FBR technology will require some time to perfect. In the meantime, Japan is pressing ahead with the MOX utilization approach, the use of plutonium in light-water reactors. Because it calls for plutonium to be used in existing reactor designs, the technology is far closer to realization.

MOX program technology utilizes MOX (mixed-oxide) fuel-a mixture of uranium and plutonium oxides. MOX fuel is different from conventional uranium fuel in that the former replaces the enriched Uranium 235-usually about 3-5 percent Of the total-contained in the latter with anything from 4-9 percent plutonium.

The truth is that plutonium is already being used as fuel in existing nuclear power plants; in fact, some 30 percent of the power the reactors generate comes from the plutonium being formed in the fission process.

To date, hundreds of MOX fuel assemblies have been used in Japan, including those used in the advanced thermal reactor "Fugen," confirming that the mixture is every bit as sound as uranium fuel. These are in addition to the successful use of MOX fuel over the past 30 years in France, Germany, the United States and other foreign countries. A total of six MOX fuel assemblies have also been used in light-water reactors in the Tsuruga and Mihama nuclear power plants in Japan, confirming that MOX fuel is as sound and safe as uranium fuel. Following the Japanese government's approval in February 1997, plans to commission a total of nuclear power plants; in fact, some 30 percent of the power the reactors generate comes from the plutonium being formed in the fission process. To date, hundreds of MOX fuel assemblies have been used in Japan, including those used in the advanced thermal reactor "Fugen," confirming that the mixture is every bit as sound as uranium fuel. These are in addition to the successful use of MOX fuel over the past 30 years in France, Germany, the United States and other foreign countries. A total of six MOX fuel assemblies have also been used in light-water reactors in the Tsuruga and Mihama nuclear power plants in Japan, confirming that MOX fuel is as sound and safe as uranium fuel.

Following the Japanese government's approval in February 1997, plans to commission a total of nine power plants using MOX fuel by shortly after the year 2000 have been announced by electric power companies. That figure is expected to double by 2010, with 16-18 in operation by that time.

The upshot: Given the rising demand for energy in Japan, the effective use of plutonium and the time needed to fully develop FBR technology, it appears likely that the MOX utilization approach will be the preferred choice of plutonium use for some time to come.

Fukushima No. 1 Nuclear Power Plant, Tokyo Electric Power Company	Takahama Nuclear Power Plant, Kansai Electric Power Plant

Japan's Plutonium Program : For Peaceful Purposes Only

SAY "PULTONIUM" TO A PERSON on the street and it's likely to evoke images of fear and danger. Yet that imagery only depicts a very limited aspect of the nuclear material. When used as an energy source, plutonium offers a number of significant advantages over existing sources.

The first and foremost key to all this, of course, is that plutonium use be restricted solely for peaceful purposes—an overriding agenda laid out for Japan's atomic energy development for the past four decades and a mandate expressedly stated in the Atomic Energy Fundamentals Act. In Japan, this principle applies to the use of all nuclear material, not just plutonium.

Japan, moreover, is a signatory and dedicated supporter of the Treaty on Non-Proliferation of Nuclear Weapons (NPT). The government has also steadfastly upheld its commitment to neither manufacture nor maintain nuclear weapons for more than 40 years. To ensure that its international and domestic pledges are kept, the nation has willingly accepted rigorous inspection by the International Atomic Energy Agency (IAEA) .

The Japanese government has man-dated both that only such stocks of plutonium will be kept that are sufficient to meet the country's immediate power generation needs and that its use will be restricted to peaceful purposes only. The issue of transparency has also been taken seriously, and information disclosure of plans to utilize plutonium and the amount of material held in reserve has been an integral part of the Japanese program.

Furthermore, reprocessed plutonium and uranium held in storage can-not be employed for weapons use without further treatment, and that won't happen with the present safe-guards in place. To augment these precautions, a battery of additional measures-from controlled access and compound security enhancements to closed-circuit TV systems-to protect storage sites from theft or terrorist activity have been implemented.

As for plutonium being an implacably lethal element to handle, that too is more fantasy than fact. It does release alpha rays, a type of radiation which, if taken into the body (by breathing, for example), can be extremely harmful to people. Yet alpha rays can be easily shielded-a sheet of paper suffices to stop them cold. So plutonium, when controlled properly, presents little danger to human health as well as great potential as a safe and reliable energy source for the future.