This report is based on data provided by LEGI-SLATE, a Washington Post Co. subsidiary.

This is a summary of recent congressional actions not reported elsewhere in The Post. SENATE El Salvador Refugees

By unanimous vote and without recommendation, a Judiciary subcommittee sent the full committee a measure that would allow illegal aliens from El Salvador to remain in the United States for up to two years without facing the threat of deportation. The measure would apply to an estimated 300,000 to 500,000 Salvadoran refugees. The bill would require the General Accounting Office to report on the refugees' health and housing conditions and the likely outcome if they returned to their native land. (S377, Sept. 30) School Prayer

The Judiciary Committee, by a 12-to-6 vote, approved a proposed constitutional amendment that would permit organized silent prayer in public schools. The amendment would have to be approved by a two-thirds vote of each chamber and ratified by three-fifths of the states to become law. Hearings have not been scheduled. (SJRes2, Oct.3) Designer Drugs

By voice vote, the Judiciary Committee approved a measure that would make it a federal crime to manufacture and sell "designer drugs," controlled substances whose chemistry has been altered slightly. Currently, such products are not considered illegal under federal law. The proposal would set a fine of up to $250,000 and a prison term of up to 15 years for those found guilty of manufacturing and distributing such drugs. (S1437, Oct. 3) Nuclear Crime Check

The Senate, by voice vote, approved a measure that would require employers to check the criminal records of potential employes at nuclear power plants. nder the measure, individuals would have to be fingerprinted and their files referred to the FBI. Currently, most background checks are limited to state and local police files. A similar measure is pending before a House committee. (S274, Oct. 3) HOUSE Superfund vote

The Merchant Marine and Fisheries Committee voted, 38 to 1, to back amendments to the Superfund reauthorization that would set up a fund to clean up oil spills, supported by a fee on imported oil, for the cleanup of oil spills. The Senate has already approved a five-year $7.5 billion Superfund reauthorization. (HR3817, Oct. 1) PRESIDENTIAL ACTION

Highway funds

President Reagan signed legislation to release about $4.8 billion in highway construction funds to the states. The bill had been delayed for two years, in part because of disagreements over what Reagan called "costly special-interest projects." The projects ultimately were eliminated. The delay has disrupted some highway construction plans. (S1514, Oct. 1)