CTBTO Radionuclide Laboratory
Workshop and Noble Gas
Workshop to take place in
Strassoldo, Italy

The Provisional Technical Secretariat of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization is organizing two events, a Radionuclide Laboratory Workshop and a Noble Gas Workshop, in Strassoldo (Udine), Italy, from 23 to 27 August 2004. The workshop will be opened by the Governor of the Region Friuli-Venezia Giulia, Dr. Riccardo Illy, together with the president of the province of Udine, Prof. Dr. Marzio Strassoldo. The workshops are expected to be attended by specialists from around twenty countries (including Argentina, Australia, Austria, Canada, China, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Russian Federation, South Africa, the UK and the USA). So far, noble gas workshops have been held in Stockholm (Sweden), Tahiti (France), Richland (USA) and Ottawa (Canada), and radionuclide laboratory workshops have taken place in Buenos Aires (Argentina), Aldermaston (UK), Blumau and Kranichberg (Austria). The Strassoldo workshop is the first joint workshop. During the Radionuclide Laboratory Workshop, experts will discuss the results of the CTBT laboratory proficiency test programme and the development of procedures for the future role of the laboratories in noble gas monitoring. Of the integrated network of seismic, hydroacoustic, infrasound and radionuclide monitoring facilities which make up the International Monitoring System (IMS), 16 certified laboratories will re-measure and analyze samples from 80 radionuclide stations, for both Treaty verification and quality control purposes. The results from an on-going experiment involving four different types of noble gas systems installed at various stations will be discussed in the Noble Gas Workshop. Participants will focus on how to continue to implement successfully this technology into the IMS network. The newest findings, which will be presented at this important scientific event, are an important further step in the accomplishing of the worldwide radionuclide verification regime of the CTBT. The Comprehensive Nuclear-Test-Ban Treaty (CTBT) was opened for signature on 24 September 1996 at the United Nations headquarters in New York. To enter into force, the CTBT must be signed and ratified by 44 States specified in the Treaty. Thirty-two of these States have so far ratified the Treaty. In total, 172 countries have signed and 114 have ratified the Treaty. Italy signed the CTBT on 24 September 1996 and ratified it on 1 February 1999. Under the terms of the Treaty, Italy hosts an auxiliary seismic station (AS050), in Enna, Sicily, and a radionuclide laboratory (RL10) in Rome, operated by the National Agency for the Protection of the Environment. Technical background The Comprehensive Nuclear-Test-Ban (CTBT) prohibits all nuclear test explosions. Compliance with the Treaty is monitored by the International Monitoring System (IMS) and the International Data Centre (IDC). The 337 facilities IMS use four complementary technologies: seismic, hydroacoustic, infrasound and radionuclide. Radionuclide technology incorporates global monitoring of radioactive aerosols, global monitoring of radioactive noble gases, and atmospheric transport, which is used to relate radionuclide detections to a likely source region. Noble gas monitoring is of key importance to the International Monitoring System, because it is practically impossible to prevent the emission of radioactive noble gases from a nuclear test. An underground nuclear explosion will only release noble gases. Therefore, a violation of the Treaty can be verified by measuring these gases worldwide. Noble gases are produced in fission and some have half-lives and radiation suitable for detection. Four isotopes of xenon (^131mXe, ^133mXe, ¹³³Xe and ¹³⁵Xe) are of interest to the CTBT monitoring system. Four different systems are utilized to measure these isotopes: one is based on gamma spectroscopy, two on beta-gamma coincidence spectroscopy and one on beta-gated gamma spectroscopy. These four systems employ different detection technologies and also differ in how they collect and process samples. One uses industrial membrane technologies, the other three rely on chromatography in charcoal columns, two of them requiring very low operational temperatures and the third one functioning at room temperature. These systems are now undergoing tests at worldwide locations in the so-called International Noble Gas Experiment (INGE). Their results are sent to the International Data Centre in Vienna for daily analysis.

For further information on the CTBTO, please see www.ctbto.org or contact:
Annika Thunborg, Chief, Public Information  
T    +43 1 26030-6375  
E    annika.thunborg@ctbto.org
M    +43 699 1459 6375       
I    www.ctbto.org