Kiwis To Build Nuclear Monitoring Station
27 January 2004
Kiwis to build nuclear monitoring station on Mauritania
Mauritania may be one of those countries that sends you to straight to the internet or an atlas to find its whereabouts, but for New Zealand scientists the west African nation is just another stop on the road to nuclear weapons disarmament.
Health Minister Annette King today signed a contract on behalf of the Government with the Comprehensive Test-Ban Treaty Organisation (CTBTO) for the installation of a radionuclide station in Mauritania.
New Zealand's National Radiation Laboratory (NRL) will build the multi-million dollar station at Mauritania. Once operational the station will form part of a worldwide network of monitoring stations being built to help enforcement of the Comprehensive Nuclear Test-Ban Treaty (CTBT).
"Our laboratory carried out the first survey for a radionuclide station in 1998 in the Chatham Islands, and since then the methods and protocols have been adopted by the CTBTO as standard," said NRL's group manager Jim Turnbull.
"NRL's involvement right from the beginning has put New Zealand at the forefront of implementing and enforcing the treaty, which is an achievement all New Zealanders can be proud of," said Mr Turnbull.
The CTBT, to which more than 160 countries including New Zealand are signatories, is seen as a major step towards the curtailment of nuclear weapons production, and eventual disarmament. The treaty can only be effectively implemented, however, if there is a monitoring system in place to verify that weapons testing is in place, and if it does occur, to identify the violator.
Because of this need, the CTBTO is setting up 321 stations in an International Monitoring System (IMS) to track any violations. It uses four technologies - radionuclide, seismological, hydroaccoustic and infrasound.
NRL's earlier contract to survey Mauritania for a suitable site for the station was its first outside the Pacific. The survey was carried out in January last year by two NRL scientists who successfully located a site on the Atlantic coast near Nouakchott, the country's main town and capital.
"While Mauritania is a rather exotic location for a monitoring site, it's also strategically very important, being both on the edge of the Atlantic Ocean and the Sahara Desert. The Sahara has of course already been used by the French for weapons testing in the past," said Mr Turnbull.
The station's construction is expected to be completed by the end of the year and it should be operating within the official IMS network early in 2005.
NRL, a business unit of the Ministry of Health based in Christchurch, has operated a comprehensive radioactivity monitoring programme since 1957.
NRL has been involved in the CTBT from formulation of the text of the Treaty to playing a significant role in establishing technical details for its IMS.
The IMS is designed to verify compliance with the Treaty and to act as a deterrent by establishing a global network of facilities capable of registering shock waves emanating from a nuclear explosion underground, in the sea or in the air, as well as detecting radioactive debris released in the atmosphere.
The network consists of 321 monitoring stations comprised of: 50 primary seismological stations 120 auxiliary seismological stations 11 hydroaccoustic stations 60 infrasound stations 80 radionuclide stations
NRL is named in the Treaty as one of 16 radionuclide laboratories and under the terms of the Treaty it will provide support to the 80 IMS radionuclide stations throughout the world.
In addition to radionuclide stations installed in Rarotonga, the Chatham Islands and Kaitaia, the NRL has installed an infrasound station in the Chathams. It has also recently commenced the installation of a Fiji radionuclide station, near Nadi airport.
What a radionuclide station does
Nuclear weapons inevitably produce fission-product radionuclides all, or at least some, of which are released into the atmosphere. These radionuclides exist either in particulate or noble-gas form. With atmospheric explosions, obviously both types are released to the atmosphere; with underwater explosions a large portion of both types may be; and with underground explosions a smaller, but still significant fraction of the noble-gas radionuclides may be vented into the atmosphere.
A global atmospheric radioactivity monitoring network which detects both forms of radionuclide would therefore provide valuable back-up for the other technologies. An important feature of the radionuclide monitoring is that there would be no false alarms, because the range of fission products produced, and their isotopic ratios, are well understood.
A major problem with this form of detection, is that it is obviously passive, and relies on the movement of air masses to the detector site. This requires the deployment of a relatively dense network of detectors in order to ensure that air masses will be carried to one or more stations from detonations at any site, in a timely manner.
The National Radiation Laboratory's website (contains further information on the CTBT, NRL's involvement, and details on how the IMS will work)