Monju reactor: A modern-day alchemist's dream?

April 16, 2014

Nuclear fuel cycle in need of alchemy amid waste disposal problems

http://mainichi.jp/english/english/newsselect/news/20140416p2a00m0na011000c.html 

"The life span of radioactive matter could be shortened from around 10,000 years to a few hundred!"

"The final disposal site (of radioactive materials) could be reduced to one-one hundredth of its planned size."

The above quotations were included within documents outlining the technology for dramatically shortening the longevity of nuclear power's residual waste, which were handed out by Akito Arima, 83 -- former minister of education and University of Tokyo president -- during an April 3 closed-door meeting among some 20 Liberal Democratic Party (LDP) lawmakers who support nuclear power.

The Monju fast-breeder reactor, which has served as the core of the nation's nuclear fuel cycle, reuses plutonium as fuel after it has been extracted from spent nuclear fuel. Because this would produce more plutonium than was consumed, it was heralded as a "dream nuclear reactor." A sodium leak, however, as well as a series of additional accidents and scandals, have meant that the actual operation of the reactor remains nowhere in sight.

"There is no such thing as impossibility when it comes to Japanese technology," emphasized Arima -- an authority in the field of nuclear physics -- during the meeting.

"Even though it may have leaked sodium, there is no problem with the (Monju) nuclear reactor," he added, prompting a lawmaker to comment, "This is the theoretical backing that we need (in order to continue with the Monju reactor)."

The following day, April 4, the LDP approved a draft of the government's Basic Energy Plan. The document outlined goals in the area of research and development for new technologies aimed at reducing nuclear waste in a bid to prolong the life of the Monju fast breeder reactor.

Despite the fact that technology aimed at short-lived radioactive substances has already been studied for more than a quarter of a century, however, there is still no prospect for its practical use. In fact, it seems possible to compare this effort with the dubious practice during the Middle Ages of trying to turn lead and other substances into gold -- rendering the present-day project, in other words, as a sort of "modern-day alchemy."

The present-day phenomenon in question is that of the OMEGA Program, which was begun by the Japanese government in 1988 to separate radioactive substances found inside nuclear waste -- such as neptunium-237, whose half-life is 2.14 million years -- and transform them into different radioactive materials with a shorter life span.

While this effort, if realized, would have been useful for processing spent nuclear fuel, it saw almost no success. One top official from the Ministry of Education, Culture, Sports, Science and Technology in effect wrote the project off, saying that it was "defunct."

An executive with the Japan Atomic Energy Agency, which operates the Monju reactor, admitted the project's limitations by commenting, "Not even the technology for separating long-lived radioactive materials from spent nuclear fuel has been established. To dispose of all presently-existing spent nuclear fuel would require around 10 (nuclear reactors capable of short life span conversions)."

"It is premature to mention (the Monju reactor) within the Basic Energy Plan," points out Tatsujiro Suzuki, former vice chairman of the Japan Atomic Energy Commission. "Any discussions regarding a 'dream project' should be separated from the reality of nuclear waste."

With no prospects existing for Monju's operation, around 44 tons of plutonium capable of being diverted toward nuclear weapons continues to accumulate in the meantime both inside and outside of Japan's borders. Last month, the Japanese government announced that it would be returning 330 kilograms of the plutonium to the United States -- a figure representing less than 1 percent of the total amount.

Additionally, if the nuclear fuel reprocessing facility in Aomori Prefecture -- which is presently seeking activation -- does end up going into full-scale operation, an additional eight tons of plutonium will be created a year. The only likelihood for its usage would be the pluthermal (plutonium-generated) project utilizing mixed oxide fuel (MOX), which is made from both plutonium and uranium. Only seven nuclear reactors among the total of 17 reactors at 10 nuclear plants waiting for government permission to restart are expected to utilize the pluthermal energy program, however, which would mean that any plutonium created at the reprocessing facility would not be able to be completely utilized even at full operation.

The Oma Nuclear Power Plant, which is presently being constructed by the Electric Power Development Co., Ltd. (J-POWER) in Aomori Prefecture, is a "full-MOX reactor" that would be the first in the country that could be powered solely by MOX fuel. The city of Hakodate in Hokkaido, however -- located within 30 kilometers from the site -- has filed a lawsuit to stop its construction.

The Shizuoka Prefectural Government has expressed opposition to pluthermal plans at the Hamaoka Nuclear Power Plant operated by the Chubu Electric Power Co. in the prefecture -- indicating that conditions in this regard are unfavorable overall.

The United States is, moreover, becoming increasingly cautious regarding the matter -- with U.S. Deputy Secretary of Energy Daniel Poneman commenting that the possibility of plutonium increasing without a clear plan for its usage is an issue of serious concern.

With the dream now gone of nuclear fuel being increased via fast-breeder reactors, the nuclear fuel cycle seems to be casting about for an alchemical process that would reduce the amount of nuclear waste.

The government is embarking on a restart of idled nuclear reactors with an Achilles' tendon -- effectively calling to mind the act of building an apartment building without bothering to install a toilet.