Underground Nuclear Explosions Control Act of 1987

Underground Nuclear Explosions Control Act of 1987 - Makes congressional findings concerning the testing of nuclear weapons.

Prohibits the obligation of funds, during a two-year period beginning 180 days after enactment of this Act, for the conducting of an underground nuclear explosion: (1) with a yield greater than one kiloton, except for two test explosions, each with a yield not exceeding 15 kilotons; (2) at a location that is not part of a single designated test area; and (3) unless a public announcement has been made at least 30 days before the date of the explosion.

Specifies that such prohibition shall not apply if the President certifies to the Congress (and the Congress approves such certification) that the Soviet Union: (1) has carried out such tests; or (2) has refused to implement reciprocal, in-country monitoring arrangements.

Declares that such limitations on nuclear test explosions shall be supplanted by a U.S.-Soviet agreement which makes reductions in the number or yield of underground nuclear explosions permitted under treaties between the United States and the Soviet Union signed before January 1, 1987.

Sets forth definitions. Specifies special procedures for considering legislation approving presidential certifications required by this Act.