International Monitoring of Nuclear Test Technologies In Use. Legal basis of the international monitoring of nuclear test Technologies used illustrated with some recent observations Present status of the international network. Mecanical signature
N, γ, β, neutrino
NUCLEAR TEST IMMEDIATE SIGNATURESBreakdown of energy released during a nuclear test
On 10 September 1996, adoption by the United Nations General Assembly in New York of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) which prohibits all nuclear test explosions.
The treaty is intended to implement a global verification regime to monitor compliance with its provisions. The regime comprise a global network of monitoring stations (the International Monitoring System), an International Data Centre in Vienna, a consultation and clarification process, On-site Inspections, and confidence-building measures.
It will enter into force when among others, the 44 states with nuclear capacity will have ratified.To date 34 states have ratified but China, North Korea, India, Pakistan and USA have still to do so.
The States Parties establish an Organization (CTBTO) to achieve the object and purpose of the Treaty.
A Provisional Technical Secretariat is responsible for
A network of globally-distributed sensors will be installed in 321 monitoring stations located at 260 facilities in over 80 countries worldwide that will provide monitoring coverage of all the continent, oceans and atmosphere.
It utilizes four technologies:
The data from the stations flow via a global communications network into the International Data Center in Vienna where analysts receive, analyze, and archive the data.
Data can be provided electronically to States Signatories.
The seismic technology consists in measuring the movement of ground surface and allows the detection of underground and underwater explosion as well as atmospheric ones close to the ground surface.
IDC Reviewed Event Bulletin:
1 January to 31 July 2007: 17,987 events
Source: CTBTO-R. Pearce/L. Zerbo
Seismograms recorded at Station PS31 (Wonju, Republic of Korea)
The infrasound technology consists in measuring the variation of atmospheric pressure and allows the detection of low frequency signals such as those of atmospheric explosion as well as underground and underwater ones close to the surface.
Noise Filtering System
Air inletINFRASOUND MONITORING STATION
-1.5 0 1.5
1 station = 4 elements
sensor + noise filtering system
Source: CTBTO-F. Guendel
The hydroacoustic technology consists in measuring the variation of pressure wave and allows the detection of underwater explosion as well as atmospheric and underground ones close to the surface.
The hydroacoustic station at Diego Garcia recorded the Tsunami Waveform at frequencies of about 0.002 to 0.01 Hz even though the site was not significantly impacted by the Tsunami. Water depth is 1500 m.
Source: CTBTO-F. Guendel
Source: W.A. Watkins et al. , 2004, Deep Sea Research
The radionuclide technology consists in collecting aerosols and gaz samples for measuring the variation of their radioactivity. This technology is the only one that can prove that the explosion detected by the others technologies is nuclear.
Credit photo: CTBTO
Credit photo: Dase & CTBTO
ARIX SAUNA SPALAXRADIONUCLIDE STATIONS (GAZ – XENON)
The Comprehensive Test Ban Treaty Organization (CTBTO) is putting into place an International Monitoring System (IMS) of 321 stations of which 248 are already installed. A private network composed of frame relay and satellite links called the Global Communications Infrastructure (GCI) conveys the data measurement to a center in Vienna-Austria.
Once the IMS is completed, the International Data Centre (IDC) will collect and archive over 1,500 channels of data from the IMS stations, comprising a daily volume of up to 10 Gbytes.
The IDC will serve as the primary central repository of all data from the IMS sensors.
Although the implementation rate of the network now stands at 80%, it’s efficiency was demonstrated by the detection of the nuclear test in North Korea and as for seismic data, countries are already using them for their national early warning tsunami centers.