An obviously irritated Sen. Sam Nunn (D-Ga.) used his opening statement at a Senate Armed Services subcommittee hearing on underground nuclear testing yesterday to criticize the Reagan administration for neither answering nor acknowledging a letter he sent to the president raising questions about Assistant Secretary of Defense Richard N. Perle's proposed novel.

Perle's agent has been conducting an auction among book publishers for the work, which appears to be based on his recent experiences in government; bidding is reported to have passed $300,000.

"I assume the administration is looking into this matter," Nunn said, adding that it is "a matter of great public concern . . . what an official can and can't do in office."

Perle, who was there to give his views on nuclear testing, sat stoically at the witness table while Nunn spoke.

Nunn said his concern was over Perle dealing with people who have no idea whether they may turn out to be characters in his novel, "at the same time he is selling the rights to a book."

Subcommittee Chairman John W. Warner (R-Va.) followed Nunn, saying soothingly that he had spoken to Defense Secretary Caspar W. Weinberger and Perle twice about the matter. "Mr. Perle is prepared at such time he and the secretary consider appropriate to make a public statement," Warner announced.

As the Door Spins

The revolving door spins for congressmen as well as for high-ranking administration officials. Yesterday, for example, the Aerospace Industries Asssociation announced that its new president and general manager will be Rep. Don Fuqua (D-Fla.), chairman of the House Science and Technology Committee.

The AIA is a Washington-based trade association representing the nation's space and defense manufacturers and has done its best to explain, among other things, why spare parts cost so much. Fuqua, who is retiring from Congress, will take the AIA job in January.

Karl G. Harr Jr., AIA's president for 23 years, will remain with the association through 1987 "to . . . ensure a smooth transition," a press release said. Harr is known for his incomprehensible presentation of aerospace facts and figures at an annual luncheon.

Legal Brief

The Supreme Court yesterday struck a blow for brevity by issuing the shortest signed opinion in at least the last 20 years. It took the justices barely 300 words (not counting footnotes) to dismiss the appeal of Lamont Julius McLaughlin, who was convicted of bank robbery and assault.

The question was whether McLaughlin's unloaded handgun was a "dangerous weapon" under a federal bank robbery law.

No dissents, no concurrences, no caveats, no ifs, ands or buts, no whosoevers, or nunc pro tunc to Justice John Paul Stevens' succinct conclusion. Stevens said the gun, loaded or not, was a dangerous weapon. Res ipsa loquitor.

Free Country

Tatiana and Efrem Yankelevich of Boston, daughter and son-in-law of dissident Soviet physicist Andrei Sakharov, are disputing an Internal Revenue Service claim that they owe $1,301 in taxes. The IRS says they owe the tax on $6,580 income from 1980; they say the money was not theirs but royalties belonging to Sakharov from works published in the United States.

If the Yankelevichs can prove that point, the IRS conceded in an answer to their U.S. Tax Court suit, the royalties will not be taxable to Sakharov because of a U.S.-Soviet treaty.