Fallout from a 1953 series of atomic bomb tests continues to plague the US government.
Two years ago the House Subcommittee on Oversight and Investigations concluded that the government had lied about the dangers of radioactive fallout from those tests.
Now US District Court Judge A. Sherman Christensen in Salt Lake City has declared that the government ''perpetrated a fraud upon the court'' in 1956, when he tried a lawsuit brought against the government by aggrieved ranchers seeking compensation for 4,390 sheep that they believed to be fallout victims.
Accordingly, in his Aug. 4 opinion, Judge Christensen withdrew his 1956 judgements, which were favorable to the government. He has ordered a retrial of the case.
Coming as it does on top of the House subcommittee finding, Judge Christensen's action is a strong condemnation of the dishonesty of the old Atomic Energy Commission (AEC), and of the administrations of the time, concerning what was then the highly controversial issue of testing nuclear weapons in the atmosphere.
In reply to protests that fallout from the tests was dangerous, the AEC consistently reassured the public there was no harm involved. The fallout would be insignificant compared to natural background radiation from cosmic rays, granite, or soil, it said.
Sheep ranchers didn't believe this when their animals died of what some veterinarians said was radiation poisoning during the 1953 tests. However, they lost their suit for compensation when there was insufficient evidence to refute government experts who relied on secret studies and data.
Reviewing all this in the light of once-secret documents, the House subcommittee concluded two years ago that the AEC ''knowingly disregarded and suppressed evidence correlating the deaths of sheep to exposure to radioactive fallout.''
Now, working with some of the same documents and with additional information brought before his court, Judge Christensen has concluded that the government committed fraud. Among other things, documents show how veterinarians who had diagnosed the sheep deaths as due to radioactivity were induced to change their minds for the benefit of the trial. There reportedly is a model letter, drafted by an Army veterinarian, which the recanting experts were to sign, plus letters showing that, in fact, they hadn't changed their diagnoses at all.
This is nasty business for government agencies that are responsible, within their fields, for the safety and well-being of citizens and their property. Although it is many years after the fact, the US public, as well as the sheep ranchers, are entitled to a thorough accounting of what actually happened during those old atmospheric bomb tests - what the dangers really were and how they were handled.
A clear understanding of this is especially needed now that the Reagan administration wants to reexamine the nuclear test-ban treaties.