After years of allowing high-level nuclear wastes to pile up at temporary storage sites across the country, utilities are ready to ship the first of 114 truckloads of spent nuclear fuel rods from western New York to Wisconsin today over the vehement protests of local officials.

The trucks, which will keep their pre-dawn departures secret to protect against sabotage, will pass through Pennsylvania, follow Interstate 80 past the suburbs of Cleveland and Chicago, then head north through downtown Milwaukee before depositing their radioactive cargo at yet another temporary storage site.

The Nuclear Regulatory Commission says the steel casks used to transport spent nuclear fuel rods are virtually indestructible. An earlier generation of casks survived being hit by a speeding train and being dropped from a height of 30 feet, the NRC said. The current casks have been checked by engineers.

But many local officials remain skeptical.

Suburban Cleveland officials have asked a federal judge to block the shipments, saying their fire and police officers are not properly trained to deal with an accident.

"I'm absolutely convinced there is no effective way for us to safeguard against an accident," said Cuyahoga County Commissioner Vincent Campanella. "Our fire chief says that if anything happens we can evacuate and pray."

"A shipment of money traveling through the state gets a great deal more protection than a shipment of spent nuclear waste," said David Curry of the Illinois attorney general's office.

The 114 shipments from western New York will be among the first to take place since a de facto moratorium on the transportation of nuclear waste began in the late 1970s. Although the 114 shipments result from a dispute over reprocessing nuclear wastes, they have served to dramatize the growing shortage of nuclear storage space. This has prompted utilities to consider shuttling their spent fuel to newer nuclear plants with larger storage areas.

Recent federal court rulings have limited the ability of cities and states to keep the wastes off their highways.

The United States does not expect to have a permanent repository for spent nuclear fuel until at least 1998. While more than 200 jurisdictions have passed laws restricting movement of nuclear waste through their territory, a federal statute allows the NRC and the Transportation Department to override local objections in choosing the routes.

That authority was upheld last month, when a federal appeals court overturned a New York City ban on nuclear shipments.

Fred Millar, director of a hazardous materials project at the non-profit Environmental Policy Institute, said that none of the nuclear shipping casks in use has been tested for leaks and that local communities are not prepared to respond in the event of a crash. He also said that questions of liability in the event of a disaster remain unresolved.

"This material is extremely hazardous stuff," Millar said. "It's fuel that has been irradiated for three years inside a reactor and is a million times more radioactive than when it went in. An NRC study shows that if 1 percent of a shipping cask were to be released in a populated area it would cause thousands of latent cancer deaths."

The possible routes for such nuclear shipments are quickly proliferating:

* Last month, a nuclear facility at Morris, Ill., southwest of Chicago, began trucking spent fuel to be stored at Wisconsin Electric Power Co.'s plant in Two Rivers, Wis.

* The Illinois plant also plans to receive spent fuel from a defunct reprocessing site in West Valley, outside Buffalo, as well as from facilities in Nebraska and California.

* The West Valley facility, once run by a Getty Oil subsidiary but now being cleaned up by New York authorities, plans future shipments of waste to Lacey Township, N.J., and Rochester, N.Y.

* Virginia Electric and Power Co. has been trying to ship spent fuel from its Surry nuclear plant to another Vepco plant in Louisa County, Va. The matter is pending in court.

* A Long Island laboratory is seeking permission to ship spent fuel through New York City to a federal facility in South Carolina.

The stage was set for this week's legal battle when a defunct reprocessing facility in West Valley, N.Y., won a court order to return the spent fuel to the utilities where it originated, beginning with the planned shipments to the nuclear plant in Two Rivers, Wis.

The utilities sent their fuel to the West Valley site during the 1970s for reprocessing, but the facility shut down and never reopened because of President Carter's ban on commercial reprocessing. After New York State filed suit, saying they could not complete a federally funded cleanup unless the fuel rods were removed, a federal judge in Buffalo ordered the utilities to take back the spent fuel by the end of 1984.

The first shipments are being handled by Wisconsin Electric, where spokesman Lisa Showers called the process "absolutely safe . . . . People are responding to some fears of the unknown."

Ohio Attorney General Anthony J. Celebrezze argues that the shipments are unnecessary because the waste is safe at West Valley. He argued in a separate complaint before the court with the NRC that the shipments are not permitted by the utilities' licenses.

But the issue has begun to fade in areas where the shipments are proceeding without incident, such as along Interstate 94 from Illinois to Wisconsin.

"I think people's fears have subsided," said Wisconsin state Sen. Joseph Strohl, an early opponent.