Union Station, the capital's imposing train terminal that has been rotting away for much of the past decade beneath a leaky roof, was granted a reprieve yesterday by the House, which passed an $11 million emergency repair bill.

The bill, which is expected to pass the Senate Monday, would authorize the money to fix the 73-year-old station's badly deteriorating roof and to make other repairs to the white granite structure. The building has been neglected over the past five years, while Congress has been unwilling to decide what to do with it.

The unanimous House action followed a three-part series in mid-November in The Washington Post that detailed mistakes by the federal government in handling Union Station.

"There are serious structural problems at Union Station and with winter coming upon us it was felt we must do emergency repairs immediately," said Nancy B. Vitali, a staff member of the House subcommittee on public buildings and grounds.

The House vote yesterday is the latest congressional action in the troubled 12-year history of federal involvement at Union Station. During that time, Congress has spent or committed itself to spend $117 million in the conversion of the once-great station into the National Visitors Center. The project -- including one of the world's most expensive uncompleted parking garages -- was plagues by bad judgment, outright deception, cost overruns, mismanagement and bureaucratic fighting, the series showed.

For the past four years proposals have been made to convert the visitors' center back to a train station. But yesterday's House action did not address questions about the future of Union Station.

According to Rep. Elliot H. Levitas (D-Ga.), chairman of the subcommittee with jurisdiction over the station, there was insufficient time left in the lameduck session of Congress to deal with a controversial $58 million bill that would restore much of the station's original layout. A major complaint about the exsisting station is the one-third-of-a-mile trek passengers must make to reach the trains.

According to Senate staff members, Levitas and Sen. Daniel P. Moynihan (D-N.Y.), the sponsor of the $11 million bill, decided last week that the simple repair measure was the only Union Station bill with a chance of passage this year.

Primary responsibility next year for passage of a bill to restore Union Station as a working train terminal will fall on Rep. James Howard (D-N.J.), who is expected to be chairman of the House Public Works Committee. One Howard aide said yesterday the congressman will hold hearings on Union Station and is committed to "doing everything he can to restoring the earlier grandeur of the building."

Jack Fish, regional director of the National Park Service, which maintains the train station, said yesterday that passage of the emergency repair bill will permit complete repairs to the roof at a projected cost of nearly $8 million.

In the past decade, damage from the leaking roof has caused extensive damage in the East and West wings of the station, requiring that some areas be closed for safety reasons. The leaks also have ruined much of the $9 million worth of restoration completed at the station to prepare it, as the National Visitors Center, for the Bicentennial celebration in 1976.

Yesterday's measure was passed by voice vote as a hasty amendment to a bill renaming a federal building in New Hampshire. CAPTION: Picture, Fixing the deteriorated roof of Union Station is expected to cost almost $8 million. By Gerald Martineau -- The Washington Post