As the Marshall Islands move toward a long-awaited September plebiscite, two judges have said they plan to dismiss a portion of the multi-billion-dollar claims filed against the U.S. government by islanders who suffered personal and property damage from nuclear weapons tests conducted on the Pacific atolls.

The Marshall Islands, site of 66 U.S. atmospheric tests between 1946 and 1958, will vote Sept. 7 on whether to approve a Compact of Free Association with the United States--ending the islands' 36-year trusteeship status--and accept a $150 million trust fund as restitution for the weapons tests.

The government has acknowledged that approximately 200 people were exposed to nuclear fallout in a 1954 explosion, and several thousand others suffered personal or property damage as a result of the tests on the archipelago of 24 atolls. The population is about 33,000.

The judicial decisions in Los Angeles and Washington could persuade some wavering islanders to vote in favor of the compact and trust fund, according to U.S. officials and islanders' representatives.

"They might conclude that the trend is against them in the courts," said James Berg, political adviser in the government's Office of Micronesian Status Negotiations. A lawyer representing a group of Marshall islanders called the Washington ruling a "partial victory," since it allowed some of the claims to proceed, but acknowledged that it could give the islanders "added incentive" to approve the compact and trust fund.

The U.S. government asserts that approval of the trust fund will nullify all cases in U.S. courts seeking damages from the tests.

In Washington, Court of Claims Judge Kenneth R. Harkins told lawyers for both sides earlier this month that he intended to dismiss all claims alleging that the U.S. illegally seized land to use for testing, according to court transcripts. However, he said he would deny the government's motion to dismiss claims alleging that the government broke an implied contract obligating it to take adequate care of islanders affected by the testing.

Of the several billion dollars in damages being requested in the claims, at least half were based on the claim that the U.S. illegally took Marshall Islands property.

A Los Angeles district court judge said Aug. 1 that he would rule against a group of Marshall islanders seeking damages from government contractors associated with the weapons testing program, according to government officials and lawyers for both sides.

U.S. officials contend that the $150 million trust fund--plus large economic aid programs planned for the islands--are reasonable answers to the troubling legacy of nearly four decades of U.S. control over the Marshalls. Fred Zeder, chief U.S. representative in the negotiations, said in a recent interview that the trust fund "will be adequate to compensate individuals for physical injury or property damage they may have suffered." However, noting that the Marshallese have filed lawsuits asking billions of dollars in damages, critics say the trust fund is less than what the islanders are due.

"We don't yet know the full extent of damage out there," said Glenn Alcalay, a former Peace Corps volunteer in the Marshalls who now works for the National Association of Atomic Veterans. "We don't know how many generations will suffer genetic damage from the tests."

The agreement, which guarantees an accumulated 18-year income of $270 million, amounts to roughly $8,200 per islander.

The economic effects of the 37-year trusteeship are pervasive. According to a General Accounting Office report issued in January, the Marshalls "have been and remain dependent upon federal funds." Zeder acknowledged that the United States "could have done better" to help develop a self-sufficient economy. But he fends off criticism by claiming that the islanders, whose economy was based on fishing before World War II, have let themselves slip into dependency.

Critics disagree. "It's a case of neo-colonialism," says Alcalay.

Donald McHenry, ambassador to the United Nations in the Carter administration, called the U.S. record "very poor." In an interview, he said, "We have not been consistent in meeting our obligations."

Coauthor of a book about U.S. trusteeship over Micronesian islands, McHenry says the Marshalls' economic dependency has "circumscribed the choices" available as they seek to end U.S. trusteeship. "They are free to choose from choices we put before them," he stated.

The Compact of Free Association grants the Marshallese domestic sovereignty but charges the United States with "full authority and responsibility for security and defense matters." Although nominally free to conduct non-military foreign affairs, the Marshalls would be required to "refrain from actions which the government of the United States determines, after appropriate consulation with the Marshall Islands government, to be incompatible with its authority and responsiblity for security and defense matters."

The focal point of the U.S. presence is a military base on Kwajelein atoll. It includes a range for testing such long-range missiles as the MX and is to remain in American hands for at least 30 years, according to a separate agreement unaffected by the plebiscite.

Residents of the neighboring Ebeye island have staged peaceful demonstrations at Kwajelein, occupying the area for several months last year. The islanders, pointing to the disparity in living and health conditions between themselves and the American military workers, say they are treated as second-class citizens in their homeland.

While 2,000 Americans live on Kwajelein with modern buildings and a golf course, 8,000 Marshallese live on Ebeye with unpaved streets and polluted water.

While U.S. officials say the agreement, if approved, would nullify the current court cases, Jonathan Weisgall, a lawyer for islanders of Bikini atoll, whose lands were used for 23 test explosions, said that "there is some question whether the United States can knock the lawsuits out of court."