Comprehensive Nuclear Test Ban Treaty (CTBT)

The Comprehensive (Nuclear) Test Ban Treaty (CTBT) bans all nuclear weapon test explosions in all environments involving a nuclear chain reaction or any other nuclear explosion. The CTBT enters into force upon deposition of the instruments of ratification by 44 states listed by name in the treaty –Austria being one of them. By the beginning of the year 2011, 182 states had signed the CTBT, whereof 153 had already ratified this international treaty. Although the total number of state parties to the treaty is increasing steadily, the number of ratifications by key states necessary for the treaty to enter into force still stands at 35. Austria ratified the CTBT on 13 March 1998.The Provisional Technical Secretariat (PTS) of the Vienna-based CTBT Preparatory Commission (CTBT PrepCom) has been operative since March 1997. The main task of the PTS is the establishment of a worldwide verification system with 321 monitoring stations, 16 radionuclide laboratories and the international data centre (IDC) in Vienna. One of the facilities under this system is the radionuclide laboratory in the Austrian Research Centre at Seibersdorf. In autumn 2001, the Seibersdorf laboratory was the first of 16 laboratories worldwide to be certified by PTS and went into service in December 2001. Additionally, a new CTBTO verification unit in the Conrad Observatory in Lower Austria was opened on 26 May 2010. This new verification unit offers continuous review and improvement opportunities for the CTBTO technologies.