A top federal insurance official called yesterday for an end to government restrictions on the amount of damages that nuclear accident victims can collect.

Deputy Federal Insurance Administrator Robert Hunter acknowledged in an interview that a study by his office during the Three Mile Island incident estimated property damage in that area at between$3 billion and $17 billion if radiation leakage reached levels substantial enough to force an evacuation.

But due to liability restrictions set by the Price-Anderson Act 23 years ago, the public would have recovered only between 3 percent and 20 percent of their losses in the event of disastrous radiation leakage, Hunter said.

The insurance regulator said he has been "totally frustrated" in attempts to get the insurance industry itself to put a price tag on the cost of full coverage against a nuclear disaster.

The federal insurance official's own estimates of plummeting property values as a result of radiation were admittedly vague. But he said he was sure that the limited insurance coverage now available "would come nowhere near" the losses that could have occurred.

Under Price-Anderson, enacted to encourage nuclear power development, the maximum liability of electric utilities in the event of a disaster is $560 million. The insurance industry pays the first $140 million; each of the U.S. utilities that own 65 existing reactors pay $5 million per reactor for the next $325 million, and the federal government pays the remaining $95 million. As new reactors are built, the federal contribution diminishes.

Three class actions already have been filed on the part of individuals and businesses claiming economic harm as a result of Three Mile Island. Two suits ask $560 million in damages for people and businesses within 20 miles of the plant; the third doesn't specify a total.

In a related letter to President Carter and several congressmen, consumer advocate Ralph Nader said, "The frightening developments at Three Mile Island make it clear that innocent American citizens are being asked to subsidize nuclear power company profits with their lives and their properties."

Nader said the National Association of Insurance Commissioners (NAIC) was "footdragging" in its four-year-old attempt to develop potential price guidelines for insurance policies that would offer total coverage in the event of a nuclear disaster. Today, such insurance is unavailable.

"This issue illustrates the determination of the insurance and nuclear industries to avoid actuarial estimates that might highlight the catastrophic damages to individuals, businesses and natural resources from a nuclear power plant accident," Nader said in an interview.

Hunter, too, criticizes the insurance industry's inability to come up with risk estimates and cost figures for full coverage.

"Our position is that if there is not that much risk, then insurance should not cost much and individuals should have the right to buy it," Hunter said in an interview. "But if it is expensive, because the risk is high. policy holders and the public in general should know.That information is needed to help the public determine whether or not nuclear power is viable. It is a public policy question."

People living near nuclear plants are paying a "tremendous subsidy" to their power companies, because they will bear most of the losses in the event of a disaster, Hunter said. Residents are forced to assume those costs because of the federal law's limits on the amount of insurance protection the plant has to pay for, he said.

Hunter expressed serious reservations about two other elements of the Price-Anderson Act. "There is a limit of 20 years for filing claims. That means that if someone develops leukemia 20 years after an accident, it's tough luck," he said. "And there is an absolute forgiveness of liability to the builder of a plant."

That means, Hunter pointed out, that the equipment manufacturer, Babcock & Wilcox, would have incurred on liability in the Three Mile Island accident if property damages had resulted.

Hunter said that "for three years we have been trying to get the insurance industry to tell us just what risks we are taking with nuclear power. If it is too dangerous, then people ought to know the risk they are taking."

But he holds little hope of resolving the issue. "Frankly," he said, "I've given up."