The Challenges of Accuracy

border control by means of detector

Radioactive materials travel — often illicitly and inadvertently. The standardisation of checks is an important task in which also the International Atomic Energy Agency (IAEA) is involved.

The Viennese physicist Christian Schmitzer who heads the IAEA's Safeguards Analytical Laboratory chairs a working group that prepared an International Standard on instruments for measuring radiation in cross-border transport in 2005. In an interview with Austrian Standards, he discusses the importance of standards and highly accurate analyses for world peace.

Mr. Schmitzer, the inadvertent movement and illicit trafficking of radioactive material occurs again and again. This is nothing new, but concerns are rising. Are they justified?

Schmitzer: There is an interesting phenomenon: The more monitoring equipment is put in place, the higher the number of incidents. This is similar to screening for cancer. Suddenly, the number of cancer cases diagnosed grows dramatically, but the number of people dying of cancer does not change. When the Soviet Union dissolved in the early 1990s, there was certainly reason for concerns as many control structures also collapsed in the East at that time. By now, the situation has stabilised again.

At the IAEA, you head the technical laboratory. You say that the number of incidents increases because of intensified checks. How did the quality of monitoring instruments develop over the past ten years?

Schmitzer: Right now, cutting-edge portal monitors are installed at the UN's Vienna International Centre. A lot of technological progress has been achieved. Moreover, a fascinating discovery has been made that is of great help to border protection services or the military. You can not only measure whether radiation is present, but — with major technological efforts — the fingerprint of nuclear material also tells you whether the radiation comes from natural and medical sources or from dangerous ones.

Do border guards also need this knowledge?

Schmitzer: It is not enough to know that something gives off radiation. During the test phase at the border crossing between Austria and Hungary, we operated a hotline for the border guards so that they were able to obtain clarifications. Thus, insecurities were eliminated about whether freight had to be held back for several hours or not.

In 2005, ISO 22188 "Monitoring for inadvertent movement and illicit trafficking of radioactive material" was prepared under your chairmanship. The standard answers the questions of how radioactive radiation can be detected according to standardised criteria under the rough conditions at the borders and which tools can be used for that purpose. How did this project come about?

Schmitzer: Measuring radiation is not easy. When you eventually characterise radiation by means of a single parameter — the dose — there must be a clear agreement on how this value is determined. Austrian standardisers have always been active in the field of radiation protection. I considered it a privilege to join a group of highly enterprising experts when I worked as a radiation protection specialist at the Austrian Research Centre Seibersdorf. My then employer agreed to bear the costs that would be incurred for this involvement in international standardisation. That was the decisive step, taken to avoid grumbling over standards 'imposed' by others — a common practice in Vienna — but to participate in shaping them. In co-operation with the international organisations based in this city, including the IAEA, we were able to gain profile.

The working group is currently dormant. Is it not necessary to fine-tune the standard?

Schmitzer: I guess that in two or three years when the manufacturers have a better grip on the new technologies we will start to review the standard.

You do not work as a radiation protection expert at the Research Centre Seibersdorf any more but head the IAEA laboratory. What are your challenges now?

Schmitzer: Following the famous 'Atoms for Peace' speech delivered by President Dwight D. Eisenhower to the UN, the IAEA was created to make sure that nuclear material is used for peaceful purposes. Hence, one of the Agency's mottos is 'Atoms for Peace'. All countries that signed the Nuclear Non-Proliferation Treaty also agreed to regular inspections by the IAEA. Our inspectors take samples for subsequent tests at the laboratory. These are performed by 45 specialists. Through analyses and extensive computations, we can find out whether the operator of a nuclear facility has a stock of 3.5 tonnes of uranium hexafluoride or 3.499 tonnes. This raises the challenge of accuracy.

How do you achieve such exact results?

Schmitzer: All laboratories world-wide are interested in being able to perform accurate measurements. Of course, each country active in the field of nuclear technology has its own laboratories. They serve for monitoring the production cycles of nuclear fuels. We take part in inter-laboratory tests on unknown samples. The results reported by three-quarters of 50 laboratories participating lie in a range of +/- 0.5%. By comparison, the EU carried out an inter-laboratory trial with 350 laboratories testing drinking water for lead some time ago (IMEP-12). Out of them, 300 only just achieved +/- 50%.

Are these amazingly accurate nuclear tests standardised?

Schmitzer: There is no specific ISO standard on them. Fascinatingly, however, the group adopted its own "standard". It was necessary to define target values for accuracy and measurement uncertainty within the group. They are called 'International Target Values' or ITV2000 for short. These values are not legally binding, but everybody complies with them.

Will this international but internal standard become an ISO standard?

Schmitzer: This would probably only be a small step now, but nobody feels that it is necessary. This may also be due to the fact that many of these efforts are made under the umbrella of the IAEA. In many fields related to the safety of nuclear facilities, the IAEA has a certain normative function. Some of these projects are implemented within the framework of ISO or in co-operation with ISO, some of them through other channels. But don't get me wrong: For specific analyses, we co-operate very intensively with ISO in many of our laboratory-related activities. Examples of the issues covered are: How do you analyse plutonium? Which methodologies exist for analysing uranium? The International Atomic Energy Agency also delegates experts to most working groups. The Agency definitely does not go it alone in all its activities.

Let's go back to border checks where analyses are carried out under rough conditions. What is the error rate here?

Schmitzer: Countries that set up monitoring equipment very early report that 95% of alarms are actually a "nuisance". They are not false alarms as radioactive material is indeed present, but it is not illicit trafficking either. Sometimes radioactive material is inadvertently included in scrap metal deliveries or contained in natural substances, such as granite or mineral fertiliser. People who received a nuclear medical treatment — for example thyroid scans — give off radiation and the alarm is triggered.

And the remaining five percent of alarms at borders relate to criminal activities?

Schmitzer: These cases clearly have an illegal background. The motive may be personal gain, but there is also deliberate smuggling within the framework of organised crime. In this context, too, foolish things may happen. In the past, for example, some people tried to smuggle Russian smoke detectors. They contain plutonium, but only in minimal quantities. The dream of getting rich fast did not come true as smoke detectors can be bought at any home improvement store here as well. Many experts disagree on the reasons why radiation sources are smuggled. After all, industrial users need certificates to document all steps from the purchase of the material to its disposal here. That raises the most worrying question: Are there unofficial users? Those may be active in international terrorism and organised smuggle.

Finally, a personal question: Was it your childhood dream to head a laboratory in the service of world peace?

Schmitzer: No, that was not my childhood dream. My childhood dream was to become a physicist and I achieved it. It all started with a simple question: Why is the sky blue? And it is wonderful when you find an answer to that question as a physicist. It was simply also good luck that I have the opportunity to work in this laboratory now within the framework of the International Atomic Energy Agency.

Do you have further aims for your career?

Schmitzer: I am very satisfied where I am now — being part of a mission that promotes peace. Let me quote Benjamin Disraeli: 'Fortune favours the prepared mind.' That is the way in which I have mostly experienced my life. You cannot bring about conditions conducive to your career, but you can be prepared to walk through doors when they open up.
 
The interview was carried out by Mag. Priska Koiner