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Last year's tsunami disaster in Japan clouded the nation's nuclear future, idled its reactors and rendered its huge stockpile of plutonium useless for now. So, the industry's plan to produce even more has raised a red flag.

Nuclear industry officials say they hope to start producing a half-ton of plutonium within months, in addition to the more than 35 tons Japan already has stored around the world. That's even though all the reactors that might use it are either inoperable or offline while the country rethinks its nuclear policy after the tsunami-generated Fukushima crisis.

"It's crazy," said Princeton University professor Frank von Hippel, a leading authority on nonproliferation issues and a former assistant director for national security in the White House Office of Science and Technology. "There is absolutely no reason to do that."

Japan's nuclear industry produces plutonium -- which is strictly regulated globally because it also is used for nuclear weapons -- by reprocessing spent, uranium-based fuel in a procedure aimed at decreasing radioactive waste that otherwise would require long-term storage.

The industry wants to reprocess more to build up reserves in anticipation of when it has a network of reactors that run on a next-generation fuel that includes plutonium and that can be reused in a self-contained cycle -- but that much-delayed day is still far off.

Japanese officials argue that, once those plans are in place, the reactors will draw down the stockpile and use up most of it by 2030.

"There is no excess plutonium in this country," said Koichi Imafuku, an official at the Agency for Natural Resources and Energy. "It's not just lying around without purpose."

In the meantime, the country's post-Fukushima review of nuclear policy is pitting a growing number of critics who want to turn away from plutonium altogether against an entrenched nuclear industry that wants to push forward with it.

Other countries, including the United States, have scaled back the separation of plutonium because it is a proliferation concern and is more expensive than other alternatives, including long-term storage of spent fuel.

Fuel reprocessing remains unreliable and it is questionable whether it is a viable way of reducing Japan's massive amounts of spent fuel rods, said Takeo Kikkawa, a Hitotsubashi University professor specializing in energy issues.

"Japan should abandon the program altogether," said Hideyuki Ban, co-director of a respected anti-nuclear Citizens' Nuclear Information Center. "Then we can also contribute to the global effort for nuclear non-proliferation."

Von Hippel stressed that only two other countries reprocess on a large scale: France and Britain, and Britain has decided to stop. Japan's civilian-use plutonium stockpile is already the fifth-largest in the world, and it has enough plutonium to make about 5,000 simple nuclear warheads, although it does not manufacture them.

Because of inherent dangers of plutonium stockpiles, government regulations require industry representatives to announce by March 31 how much plutonium they intend to produce in the year ahead and explain how they will use it.

But, for the second year in a row, the industry has failed to do so. They blame the government for failing to come up with a long-term policy after Fukushima, but say they nevertheless want to make more plutonium if they can get a reprocessing plant going by October.

Kimitake Yoshida, a spokesman for the Federation of Electric Power Companies, said the plutonium would be converted into MOX -- a mixture of plutonium and uranium -- which can be loaded back into reactors and reused in a cycle. But technical glitches, cost overruns and local opposition have kept Japan from actually putting the moving parts of that plan into action.

In the meantime, Japan's plutonium stockpile -- most of which is stored in France and Britain -- has swelled despite Tokyo's promise to international regulators not to produce a plutonium surplus.

Its plutonium holdings have increased fivefold from about 7 tons in 1993 to 37 tons at the end of 2010. Japan initially said the stockpile would shrink rapidly in early 2000s as its fuel cycle kicked in, but that hasn't happened.

Critics argue that since no additional spent fuel is being created, and there are questions about how the plutonium would be used, this is not a good time start producing more. They also say it makes no sense for Japan to minimize its plutonium glut by calling it a "stockpile" rather than a "surplus."

"It's a simple accounting trick," said Edwin Lyman, a physicist with the Union of Concerned Scientists. "It's laughable. And it sends the wrong signal all around the world."

Officials stress that, like other plutonium-holding nations, Japan files a yearly report detailing its stockpile with the International Atomic Energy Agency. But it has repeatedly failed to live up to its own schedules for how the plutonium will be used.

From 2006 until three years ago, the nuclear industry said the plutonium-consuming MOX fuel would be used in 16-18 conventional reactors "in or after" 2010. In fact, only two reactors used MOX that year. By the time of the earthquake and tsunami last year, the number was still just three -- including one at the Fukushima plant.

In response to the delays, the industry has simply revised its plans farther off into the future. It is now shooting for the end of fiscal 2015.

"There really is a credibility problem here," said Princeton's von Hippel, who also is a member of the independent International Panel on Fissile Materials. "They keep making up these schedules which are never realized. I think the ship is sinking beneath them."