Nuclear Waste Policy Act Amendments of 1986 - Removes the statutory requirements and deadlines for second (and subsequent) nuclear waste repositories, thus eliminating Department of Energy authority to site such repositories. Removes the volume limitations placed upon first repositories. Instructs the Secretary of Energy to revise the repository mission plan to reflect the provisions of this Act and to submit such revisions within six months after enactment of this Act. Amends the Nuclear Waste Policy Act of 1982 to prohibit the Secretary from expending funds from the Nuclear Waste Fund for any activity relating to a second or subsequent repository.