The Rokkasho reprocessing plant begins a crucial test to determine the viability of extracting plutonium from spent nuclear fuel.

`There is no risk of a chain reaction occurring (with depleted uranium) ... .'

JAPAN NUCLEAR FUEL OFFICIAL 　Discussing the safety of the test

The government's program to recycle spent nuclear fuel kicks into high gear today when the country's first commercial reprocessing plant in Rokkasho, Aomori Prefecture, finally begins tests using uranium.

Much attention is focused on the tests: Any flaws or accidents that reveal the potential for radioactive contamination could jeopardize the entire recycling plan.

Over the next year, the plant, built and operated by Japan Nuclear Fuel Ltd., is expected to run tests using about 53 tons of depleted uranium left over from the enrichment of natural uranium to make fuel.

Originally scheduled to begin in June of last year, the tests were delayed by the discovery in 2002 of construction flaws in the pool used to store spent fuel.

The reprocessing facility, built at a cost of 2.14 trillion yen, is located on a vast 3.8-million-square-meter compound in a remote site in the northern part of the prefecture. In its final stage, the test will involve extracting plutonium from spent fuel that is cut into small pieces several centimeters in size and chemically treated with nitric acid.

Because the plutonium can then be used as fuel in reactors, the recycling program has been hailed as an answer to the nation's problem of energy security.

The hope is to process up to 800 tons of the 900 to 1,000 tons of spent fuel produced at power plants every year, yielding about 4.5 tons of plutonium.

Initially, the plutonium was meant for use in fast-breeder reactors, but plans changed after an accident at the nation's sole prototype fast-breeder reactor, Monju, in 1995. Now, the plan is to mix plutonium with uranium for use as a fuel in conventional light-water reactors.

Since its major facilities were completed in 2001, the Rokkasho plant has geared up for operations in stages, first by running tests with water and chemicals. The latest test involving depleted uranium will determine whether the spent fuel can be safely cut up into pieces and dissolved in nitric acid.

The final stage, called the active test, in which spent fuel is actually reprocessed, is scheduled to begin in December 2005.

This month, Japan Nuclear Fuel sought to reassure locals in leaflets handed out to each of the 4,000 households in the Rokkasho area. The company says that the test will only raise by an estimated one-10,000th the level of naturally existing radioactivity in the area.

The company also took the unusual step of posting on its Web site 190 potential emergency scenarios, including possible leaks of low-level radioactive wastewater from pipe joints and breakdowns of the machinery used to cut the spent fuel into pieces.

In each case, however, the company concluded that the environment would not be seriously affected.

The depleted uranium to be used in the test contains less fission-prone uranium-235 than does natural uranium and is thus easier to handle.

``There is no risk of a chain reaction occurring (with depleted uranium) and no need to even think about people being seriously exposed to radioactivity,'' said an official with Japan Nuclear Fuel.

Because of the low risk, depleted uranium has been used in tests at other nuclear facilities. However, when the Tokai Reprocessing Plant for research and development, run by the Japan Nuclear Cycle Development Institute in Ibaraki Prefecture, conducted a uranium test for 19 months from 1975, 39 incidents of minor trouble involving the substance were reported.

Government officials are eager to avoid a repeat of the sodium leaks that plagued the Monju prototype fast-breeder reactor in the 1995 accident. It was that accident that led the government to suspend development of fast-breeder reactors for commercial use.

A similar serious accident at Rokkasho could spell the end of the nation's nuclear fuel recycling program.

In June, the government's Atomic Energy Commission brought together experts to debate whether the current nuclear fuel recycling plan should proceed.

They concluded last month that although the current plan is more costly than not recycling spent nuclear fuel at all, it was a good plan and should proceed.

But some nuclear experts warn it will take two to three years to fix problems that may arise during the uranium test and that the Rokkasho facility may miss the target date of July 2006 to start operations.

The Rokkasho facility can anticipate running into trouble. The French company Cogema, which offers technical support to Japan Nuclear Fuel, has reported about 1,500 troubling incidents of some kind at the company's nuclear recycling plants since the 1990s.

Hideyuki Ban, co-director of the Citizens' Nuclear Information Center, cautioned the Atomic Energy Commission's panel that the Rokkasho facility may fail to function even up to half of its capabilities.

And unless the uranium test is an overwhelming success, the power companies may once again urge that the recycling program be scrapped altogether.

Because it requires such careful handling to prevent radioactive contamination, utilities operating nuclear power plants have been concerned about taking the next step of reprocessing actual spent nuclear fuel.

Decommissioning costs also begin to mount. It is estimated it would cost 450 billion yen to decommission Rokkasho after the uranium test. But the cost jumps to an estimated 1.55 trillion yen if spent fuel is processed.(IHT/Asahi: December 21,2004)