Nuclear terrorism is defined as a terrorist assault with nuclear or radiological weapons, or an attack against a nuclear power plant. To date no such act has taken place. In June 2002, Jose Padilla was arrested for allegedly planning a radiological attack on the city of Washington, DC; Padilla has been under military arrest as an "enemy combatant" since then.
In August 2002, the United States launched a program to track and secure enriched uranium from 24 Soviet-style reactors in 16 countries, in order to reduce the risk of the materials falling into the hands of terrorists or "rogue states". The first such operation was Project Vinca, an operation in Serbia "to remove a quantity of highly enriched uranium, sufficient to produce 2-1/2 nuclear weapons from a research reactor near downtown Belgrade" .
In order to reduce the danger of attacks using nuclear waste material, European Union Commissioner Loyola de Palacio suggested in November 2002 the creation of common standards in the European Union, especially in the new member states operating Soviet-era reactors, for subterranean nuclear waste disposal.