Natalie Barb reports for BBC News 24

And it is not just freelance terror organisations who might want to get hold of this technology - some countries who aspire to membership of the exclusive nuclear club could attempt to build their own bombs using stolen plutonium.

Usually this means trying to smuggle the radioactive material out of foreign power stations and other nuclear installations.

Cases of smuggling are reported almost every month. The best known incident occurred in August 1994 when about a quarter of a kilo of weapons-grade plutonium-239 was seized at Munich airport.

The European Commission is so concerned that dangerous materials might fall into the wrong hands that it is now heading an international project to help countries bring in more stringent controls on the storage and movement of the isotopes used in weapons manufacture.

Accounting system

The Russians, in particular, now seem keen to stop the flow of smuggled uranium and plutonium disappearing across its boarders. However, it has proved difficult to keep track of nuclear matter without an accurate accounting system.

Obninsk has sent its engineers on the training course

That is why the Commission has offered to run an extensive training programme to help the Russians carry out a proper audit.

"We have been encouraging them to look at the systems of control that we have," says Gordon Adams, a Member of the European Parliament with interests in research, technology and energy.

"We've now got to the situation where the training of inspectors of nuclear installations and the training of operators is going to be undertaken at Obninsk with the help of ourselves and, indeed, the Americans."

Obninsk is home to the world's first nuclear power station, about 100 km south of Moscow.

Its nuclear engineers will become the new "atom inspectors" who will train a generation of other Russians in the new techniques. The engineers are completing their training at the Joint Research Centre in Northern Italy.

High accuracy

One of their first tasks has been to learn how to measure plutonium with high accuracy. The intention is that all nuclear materials entering and leaving nuclear installations will be weighed to within one 10,000th of a gram. This should stop any material from being "mislaid".

Precision is vital

As well as being able to weigh the plutonium in whatever form it comes, It is also essential to be able to detect the chemical and nuclear signature of every piece of material.

In this way, it will be possible to check the grade of the isotope and see whether or not it is pure enough for the manufacture of weapons - the plutonium or uranium isotopes used in a nuclear weapon are about 90% pure.

Once the engineers have established the exact composition of a sample, they can store it in a container that uses sealed bolts to make it tamperproof.

The bolts are tamperproof

These bolts can then be checked with computers for signs of interference. The Russians are hopeful such thoroughness will alleviate the problem of international smuggling.

European Commissioner Edith Cresson says it was essential that the EU offered its expertise.

"It was extremely urgent, that is why the Joint Research Centre which is under my responsibility at the Commission took matters in hand and undertook at the same time to examine the situation, train the people in charge, and subsequently monitor operations."