Harper & Row has bought the Charlotte Fedders story at an undisclosed sum reported to be in excess of $100,000. She'll coauthor it with Washington writer Laura Elliott in an expanded version of Elliott's April 1986 Washingtonian magazine article.

"We're very excited about it and expect it to have vast appeal," Larry Ashmead, trade editor at the New York publishing firm, said yesterday. "We think it will open a lot of doors and bring a lot of people out of the closet who were hesitant to talk about domestic violence before."

*Fedders' divorce suit against John Fedders, a former Securities and Exchange Commission official, hit the national press in 1985, two years after she testified in court that the $63,000-a-year presidential appointee had repeatedly beaten her during the 18 years they were together.

Last month she filed for bankrupcty, stating that she had debts totaling nearly $130,000 that she could not pay and describing a spartan life style dictated by $1,500 a month in child support payments and her small salary at a private school. Earlier this month John Fedders petitioned the court for improved child visitation arrangements and alleged that his ex-wife has "jeopardized the mental health" of their five sons by "involving them in publicity regarding the past difficulties of the family."

Coauthor Elliott, who said yesterday the contract with Harper & Row hasn't yet been signed but should be soon, sees a readership of "well-educated, well-heeled women who are reluctant to go to crisis centers for help."

"We want to do more about the battered-wife syndrome, about how the children are affected and about divorce laws and the attitudes of the courts," said Elliott.

Nancy Reagan will deliver what the White House is describing as "a major talk" about drug abuse today before the World Affairs Council of Los Angeles, a forum usually devoted to the pronouncements of experts on foreign affairs.

Edmonde A. Haddad, council president, said about 1,500 members have reserved seats at the luncheon and that the first lady may draw a larger crowd than her husband did the last time he addressed the group.

"In fairness to the president," Haddad added quickly, "the Century Plaza's ballroom, where Mrs. Reagan will speak, is larger than the one where the president spoke."

Mrs. Reagan's 25-minute speech will be followed by a question-and-answer session. Haddad said the Q-and-A is almost never dropped, although it was at Richard Nixon's request last winter ("He was making a major policy statement on Soviet-American relations," Haddad explained). Another time was at the request of Buckingham Palace when Britain's Prince Charles addressed the group.

The first lady will be on familiar turf with old friends at a private preluncheon reception hosted by longtime Reagan intimates, Los Angeles industrialist Earle Jorgensen and his wife Marion, who is secretary of the council's board. Others expected are former attorney general William French Smith, a past chairman of the council, and his wife Jean.

The word around Cape Cod is that the reason Caroline Kennedy and Edwin Schlossberg aren't going to be married in the Kennedy family church at Hyannis is that they wanted a rabbi to participate in the July 19 ceremony and the parish priest at St. Francis Xavier Catholic Church refused. St. Francis Xavier was where Caroline's cousin Maria Shriver married Arnold Schwarzenegger in April.

But yesterday, a spokesman for Jacqueline Kennedy Onassis said she didn't think that was the reason, but rather that "the church Caroline chose to be married in" was Our Lady of Victory, in nearby Centerville, where another cousin, Sydney Lawford, was married.

Spokeswoman Nancy Tuckerman described the nuptials as "a Catholic ceremony" in which there will be no mass. "There will be only one service," she said of the late-afternoon ceremony.

Tuckerman said Kennedy has been overseeing the wedding preparations herself. "She's very well organized."

Invitations have already gone out, according to Tuckerman, who confirmed that Sen. Edward M. Kennedy will give the bride away. A reception similar to that for the Shriver wedding is planned at the Kennedy family compound in Hyannis Port.

bat16 Source Theatre's new production of "Skyfall," by the Hungarian playwright Miklos Vamos, had a visiting countrywoman in the premiere audience Sunday night: Katalin Radics, one of the Hungarian Socialist Workers Party's leading officials.

Radics, who accompanied Ambassador Vencel Hazi and his wife Judit, listened carefully but seldom smiled at the work Vamos wrote more than a decade ago and which since has been adapted for Hungarian national television. Radics appeared never to have seen the play, which combines the Vamos touch of whimsical irony with more sobering themes about economic hardships in a police state. If the Americans found it revealing as well as entertaining, Radics evidently remained unmoved.

At a buffet supper afterward, she asked Pierre Frantz-Chapou, executive director of the Washington-based American Foundation for the Protection of the Heritage of Mankind, what exactly he had in mind by bringing the play to the United States.

"Nothing," said Chapou, who met Vamos in Budapest and decided to help underwrite "Skyfall" for a Washington run. His only ulterior motive was an artistic one of sharing contemporary Hungarian art with his fellow Americans, he said.

Radics may or may not have been convinced. Next time, she told Chapou, she might choose the play.

Tourists hoping to tour the White House later this summer may be out of luck. A National Park Service spokesman said yesterday that the residential quarters of the mansion will be closed from Aug. 16 to Sept. 7 so work can be done on the heating and air conditioning systems.

"President and Mrs. Reagan have agreed to be away" during the repairs, Sandra Alley said. The Reagans obligingly will be vacationing at their Santa Barbara ranch.

Alley said White House tours will be decided on a day-to-day basis and suggested that visitors telephone 456-7041 to ask if tours of the state rooms will be conducted on a particular day.

The work is part of a two- to three-year, $5 million renovation of the mansion's utility systems.