Nuclear Reprocessing in Japan

Charles Dunn
January 25, 2011

Submitted as coursework for Physics 241, Stanford University, Winter 2011

Fig. 1: The rise of Japanese nuclear power. Source: Wikimedia Commons

The reprocessing of nuclear fuel has long been lauded for conserving nuclear fuel and reducing dependence on mining, but criticized and largely unused because of public skepticism and high costs. For Japan the concerns are amplified due to miniscule domestic energy resources and a shaky nuclear past. Japan only manages to produce 4% of its energy domestically, and reprocessing would at least make nuclear fuel a semi-domestic energy source. [1] The need for energy independence, however, could counteract Japan's proactively antinuclear policies and public opinions.

Just over two decades after Hiroshima and Nagasaki, Japan's first nuclear reactor began operation in Tokai, just Northeast of Tokyo. Although the government has kept a tight lid on its nuclear program since its creation, some organizations have released information. According to the World Nuclear Association, by 1973 there were five active nuclear reactors and more on the way when OPEC's oil embargo forced Japan to rethink its energy dependencies. The government's new plan involved a much greater diversification in energy imports along with substantial nuclear energy development. Today, 54 nuclear power plants operate in Japan, accounting for about 30% of their total energy production. [2] In 2008, the Japan Atomic Energy Agency set a goal of 53% by 2100. [3] Since 1992, Japan has been reprocessing fuel in Rokkasho and other locations in small amounts, but has controversial plans to expand the capacity of the plant by a factor of ten. By 2020, the plant is hoping to reprocess 1.5 million tons of uranium every year. [2]

By reprocessing the spent uranium from power plants, plutonium is extracted for either fast breeder reactors or mixed oxide (MOX) fuel. Japan still has an active fast breeder reactor program, and just recently began testing the system again in Monju. [4] Ideally, the plutonium from reprocessing would be stockpiled until fast breeder reactors are fully tested and commercially available. The energy yield from a fast breeder reactor is much higher than even MOX fuel, and provides a very long-term solution to Japan's energy dependence. Unfortunately, the estimated year of completion for the fast breeder reactor project is always decades in the future, with the current date set at 2050. [5]

With the unreliability of a fast breeder reactor, MOX fuel is the only option for Japan to use its plutonium from reprocessing. MOX fuel is already in use in multiple Japanese reactors, and by 2011 should be used by more than 16 reactors. Although the Rokkasho reprocessing plant would allow Japan to produce its own MOX fuel, for years it has sent uranium to France for reprocessing. [6] Although MOX fuel would complete the fuel cycle for Japan, development of MOX technology faces the same problem as the entire nuclear program in Japan; the Japanese public is adamantly opposed to it, which has greatly slowed development, and in some cases canceled plans for progress. [7]

Fig. 2: Rokkasho Processing Plant, Aomori, Japan. Source: Wikimedia Commons.

In the US, nuclear guilt and misinformation have historically caused nuclear skepticism, but in Japan the mentality is quite different. Their anti-nuclear weapon position is entwined in their culture, and any action relating to weapons-grade plutonium is always met with powerful opposition.

The atomic bombs dropped during World War II are certainly still in the public conscience, and just the existence of separated plutonium from reprocessing makes many uneasy. A stockpile of plutonium is a perfect target for terrorists or other states hoping to go nuclear. Although extremely unlikely, there is even the possibility of Japan itself using the plutonium for nuclear weapons. Former US Defense Secretary James Schlesinger has even suggested that Japan could feel pressured to pursue its own nuclear weapons program as the US adopted a "no first strike" policy with nuclear weapons, weakening its nuclear umbrella which protects Japan. With a new round of elections, even this small possibility has been eliminated, but the Japanese public still have a right to be skeptical about Japan's ability to guard and handle its nuclear resources properly. [8]

In about 50 years of nuclear programs, Japan has seen numerous nuclear accidents. The first incident was in 1995 at Monju, the site of Japan's experimental fast breeder reactor, where highly reactive sodium leaked, causing a fire and delaying the fast breeder program by a decade. In 1997, another fire and an explosion occurred at the Tokaimura processing plant which was making small quantities of fuel for the fast breeder program. [5] In 1999, Japan suffered its most severe nuclear incident as a holding container of Uranium unintentionally went critical, again at the Tokaimura plant. The incident has an American parallel in the Three Mile Island incident; the water involved in the neutron reactions boiled away, eventually returning the container to subcriticality. Nonetheless, 300,000 residents were evacuated in a high profile failure of personnel training and equipment checks. [9]

Just as recently as 2003, Japan revealed that it had lost track of enough plutonium to make 25 nuclear weapons. Although poor bookkeeping was suspected rather than theft, it put a spotlight on the issues of having a massive stockpile of plutonium. [10] Another fire and automatic shutdown at the Kashiwazaki-Kariwa nuclear power plant following a magnitude 6.8 earthquake also confirmed many fears that Japan is too earthquake-prone to safely operate nuclear power plants. [11]

All of these incidents add to public skepticism over not just reprocessing fuel, but the entire nuclear program in Japan. Even worse for reprocessing advocates, reprocessing fuel will actually cost more than using new imported uranium in terms of yen per kilowatt-hour produced. Some estimates claim that reprocessing fuel costs 50% more than simply importing more uranium and disposing of the spent fuel directly. [2] Consequently, the Japanese public as well as many nuclear experts are still opposed to Japan's reprocessing. Despite the governments endorsement of the project, funding has been on the decline for decades, signifying doubts held by the government as well. [5]

Despite these protests, the Rokkasho processing plant has been over a decade in the making, and is set to operate at full capacity in the next few years, producing 4 tonnes of plutonium per year. Further advances, including the Plutonium-Uranium Exctraction process (PUREX) mean that uranium is left blended with extracted plutonium, lessening the risks of plutonium storage. [2]

Japan has been highly invested in a large scale nuclear program for decades, and MOX fuel, fast breeder reactors, and a closed fuel cycle for just as long. [5] Despite astronomical costs and years of delays, a full scale reprocessing plant would give Japan much greater energy independence, while reducing large stockpiles of spent uranium. The price Japan pays to reprocess its nuclear fuel is more an indication of the value of energy independence than of the stubborness of Japan's nuclear energy policy. If Japan can avoid more nuclear incidents and continue with its fast breeder research, in all likelihood Japan's closed fuel cycle will isolate them from uranium price fluctuations and the already instable supply of oil. Though expensive in the short-term, reprocessing could easily provide Japan with a long-term solution to its energy problems, putting them well ahead of most other countries with far greater natural resources.

© Charles Dunn. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] H. Koshoji, "Japan Pursues Plutonium-Based Fuel," UPI Asia, 6 Apr 09.

[2] "Nuclear Power in Japan," World Nuclear Association, Jan 10.

[3] E. Arita, "Rokkasho Plant Too Dangerous, Costly: Expert," The Japan Times, 27 Nov 08.

[4] "Monju Fired Up After Four-Day Halt," The Japan Times, 2 Jun 10.

[5] T. B. Cochran et al., "Fast Breeder Reactor Programs: History and Status," International Panel on Fissile Materials," Research Report 8, February 2010.

[6] E. Chanlett-Avery and M. B. Nikitin, "Japan's Nuclear Future: Policy Debate, Prospects, and U.S. Interests," Congressional Research Services, CRS Report for Congress RL34487, 19 Feb 09.

[7] W. D. Turner, "Japanese Plutonium Stockpiles: A Transportation, Storage, and Public Relations Challenge," J. Environment and Development 12, 99 (2003).

[8] S. Fukuyama and H. Umebayashi, "Japan Ready for 'No Nukes'," The Japan Times, 25 Aug 09.

[9] "Tokai-Mura Accident, Japan: Third Party Liability and Compensation Aspects," Nuclear Law Bulletin No. 66, p. 13, December 2000.

[10] B. Rahman, "Japan 'Loses' 206kg of Plutonium," Financial Times, 28 Jan 03.

[11] D. Cyranoski, "Quake Shuts World's Largest Nuclear Plant," Nature 448, 392 (2007).