The United States is moving toward allowing Japan routinely to ship weapons-grade plutonium halfway around the globe. Under a proposed nuclear cooperation agreement, the US would give the Japanese blanket approval to move large amounts of the material by plane from reprocessing plants in Europe to Japan. The plutonium would be used as fuel in a new generation of nuclear power plants.
Currently, Japan must get US permission each time it moves plutonium made from US-supplied fuel or fuel from US-built plants.
Critics argue that the new 30-year agreement - hashed out in January, but yet to be signed - opens a Pandora's box of potential safety and security problems. Still, it is expected to be signed and submitted to Congress later this month. The agreement can be blocked only if both houses move to reject it, which is considered unlikely.
The anticipated route for the plutonium flights is over Canada, with a possible refueling stop in Alaska. Some analysts worry that a plane crash could spew highly toxic plutonium across the countryside. Crashproof canisters are under development in several countries, but they have yet to be perfected.
Alaska Gov. Steve Cowper sent a letter to Secretary of State George Shultz in April, cautioning that the shipments could have ``tremendous consequences for the health and safety of Alaskans as well as for the state's environment.'' Alaska officials want Washington to prepare an environmental-impact statement before allowing the flights to begin.
The Canadians, meanwhile, have indicated that they might try to block the flights, once details of the plan are made clear. US officials emphasize that many specifics, such as routes and refueling stops, are yet to be determined.
``Various environmental aspects will be reviewed prior to a decision to ship by a particular route,'' a US State Department official says.
Another focus of concern is the potential security risks associated with large-scale movements of plutonium. Less than 15 pounds of the material is enough to build an atomic bomb.
The Defense Department, one of several US agencies required to comment on the agreement, has reportedly recommended that the administration not sign the accord. The trade journal Nucleonics Week quoted sources inside the Pentagon who said they were concerned about the long-term ``programmatic approval'' granted in the agreement. Some analysts worry that this will weaken Washington's grip on reprocessing activities overseas.
``This agreement is part of a larger effort [by the US] to be a reliable nuclear supplier,'' while also retaining maximum control, says the State Department official, who emphasized the link between such accords and the administration's approach to nonproliferation.
The US controls much of the nuclear fuel used in industrialized countries, a legacy of the 1950s and early '60s, when the US had a monopoly on supplies.
Each year, some 100,000 pounds of plutonium are discharged in the waste from the world's nuclear power plants. Britain, France, West Germany, and Japan are developing plants that extract the plutonium, which can then be used to supplement fresh reactor fuel.
Advocates see this as a way of conserving uranium reserves and securing greater energy independence.
The Reagan administration, which shelved the American reprocessing program several years ago, has found it increasingly difficult to block such activities among its allies. And so it has sought to focus on security.
Paul Leventhal, president of the Nuclear Control Institute, a Washington-based group that advocates tighter controls over nuclear materials, says that plutonium is simply too dangerous to transport in bulk over long distances. ``What we're going to have,'' he says, ``is an industry that sends prodigious amounts of atom-bomb material over tenuous transport routes halfway around the globe.''
The Nuclear Control Institute recently published a study detailing the problems that countries are having in developing plutonium containers that won't burst open during an air crash. The US Nuclear Regulatory Commission has set strict standards for such containers. So far, however, only a relatively small one (capable of carrying about 4.5 pounds of plutonium) has been approved. And just one cask per flight is permitted.
The institute estimates that Japan will need containers with much greater capacity to transport economically the plutonium expected to be generated by Japan in the 1990s. Japan carried one bulk shipment of plutonium home from Europe by sea in 1984 - accompanied by US and French warships. At that time, US and Japanese officials said future shipments would go by air.
Meanwhile, negotiations over nuclear cooperation with Switzerland and the international organization Euratom have been put on hold. The Europeans want to see what kind of terms the Japanese are able to get before pressing forward with their own demands.