Bush’s proposals would save the United States billions of dollars by allowing the closing of several aging and unsafe nuclear plants, already facing a massive and costly cleanup. It would help Gorbachev by enabling Moscow to shut down a number of even more unsafe weapons-oriented nuclear plants. No date has been set for the announcement, but administration officials expect Bush will offer the proposals before he meets Gorbachev in Madrid on Oct, 29, a day before the opening of the Mideast peace conference.