BBC NEWS Americas Africa Europe Middle East South Asia Asia Pacific
BBCi NEWS   SPORT   WEATHER   WORLD SERVICE   A-Z INDEX     

BBC News World Edition
    You are in: Science/Nature  
News Front Page
Africa
Americas
Asia-Pacific
Europe
Middle East
South Asia
UK
Business
Entertainment
Science/Nature
Technology
Health
-------------
Talking Point
-------------
Country Profiles
In Depth
-------------
Programmes
-------------
BBC Sport
BBC Weather
SERVICES
-------------
EDITIONS
 Tuesday, 17 December, 2002, 14:03 GMT
Iraqi samples under the microscope
UN weapons inspectors, AP
UN weapons inspectors continue to collect samples
Detailed analysis on samples taken at suspected nuclear sites in Iraq is underway at the International Atomic Energy Agency's (IAEA) laboratories.

Even if they paint the walls, and they completely change the floor - and they've tried this - we still find the traces in this kind of sample

David Donahue, IAEA
Eight samples are reported to have arrived at Seibersdorf in Austria and another 20 are expected at the weekend.

The samples are being collected by wiping sterile swabs across walls and other solid surfaces in factories, palaces and warehouse throughout Iraq.

If the scientists find traces of uranium that could be used in a weapons programme, the samples will be sent to other laboratories around the world to confirm their results.

Other samples of water, air and soil will also be analysed by the Agency.

The process is fairly long, but results are expected at the earliest in the middle of January.

Testing samples

The weapons inspectors are equipped with specially designed kits.

These contain 10-centimetre-square cotton swabs which they use to collect tiny particles of dust from suspected buildings.

Several samples are collected from each site so tests can be repeated and the IAEA's results can be independently verified.

These are then carefully sealed in two plastic bags to ensure they are kept clean.

Although initial analysis of the samples can be done on site, further tests need to be carried out in the laboratory, so samples are sent on to the scientists in Austria.

On arrival the bags are screened using gamma-ray spectroscopy and x-ray fluorescence, which can detect particles of uranium or plutonium - two elements that can be used to make atomic bombs - that are only a thousand millionth of a gram.

If the scientists find traces of these elements, the bags will then be opened and the swabs looked at more closely.

According to David Donahue, the operational head of the IAEA's laboratory, if there is something to find then they will find it.

"Even if they paint the walls, and they completely change the floor - and they've tried this - we still find the traces in this kind of sample."

Enriched uranium

Finding traces of uranium or plutonium will not be evidence of a weapons programme.

Radioactive materials can be used for other purposes, such as medicine.

But finding enriched uranium - an unusual ratio of particular types of atoms - in large amounts would be significant.

David Donahue told the BBC: "Uranium is a natural element, it's present in all nature. But then people who want to make nuclear weapons have to enrich it, to enrich the U-235. And so we look for uranium which has been isotopically altered."

According to David Donahue, the Iraqis have produced this material previously.

"What the Iraqis did before '91, the first Gulf War, is that they had an enrichment programme that took the material up to about 5%. And this was just the start of their programme. They were obviously aiming to go much higher.

"The agency inspectors went back and confronted them with this and they finally admitted that they had this programme, and they showed us all the equipment they had taken away and buried in the desert."

See also:

17 Dec 02 | Americas
26 Jan 02 | Middle East
08 Nov 02 | Americas
Internet links:


The BBC is not responsible for the content of external internet sites

Links to more Science/Nature stories are at the foot of the page.


E-mail this story to a friend

Links to more Science/Nature stories

© BBC ^^ Back to top

News Front Page | Africa | Americas | Asia-Pacific | Europe | Middle East |
South Asia | UK | Business | Entertainment | Science/Nature |
Technology | Health | Talking Point | Country Profiles | In Depth |
Programmes