The ANSTO nuclear medicine facility in Lucas Heights, Australia. Credit: ANSTOThe Australian Nuclear Science and Technology Organisation's (ANSTO) medical isotope production facility announced in January that it had become the second in the world to install a high-resolution monitoring system to track emissions from its medical radioisotopes production facility under an initiative led by the US Department of Energy's Pacific Northwest National Laboratory (PNNL).
ANSTO and PNNL said the detector system was installed in October at the medical isotope production facility at Lucas Heights. The first such system had been installed in a monitor stack at the Institute for Radioelements (IRE) at Fleurus in Belgium. Both IRE and ANSTO produce molybdenum-99 by irradiating uranium in a reactor. The process releases gaseous fission products including xenon isotopes. While representing no danger to the public, the isotopes resemble those produced by a nuclear explosion.

The Comprehensive Nuclear Test Ban Treaty Organisation (CTBTO) Preparatory Commission operates an international monitoring system to look for signs of nuclear explosions. In the event of a suspected explosion, information collected from monitors such as those installed at the Lucas Heights and Fleurus facilities will help to ensure emissions from medical isotope production are not misinterpreted. Judah Friese, PNNL principal investigator, said: "These first-of-their-kind sensor systems, one in each hemisphere, will help with international measurements for detecting underground nuclear explosions." More installations are planned at locations around the globe to increase confidence in international nuclear explosion monitoring, he added.

The Vienna-based CTBTO Preparatory Commission was founded in 1996 and is responsible for promoting the CTBT and the developing the verification regime so that it is operational when the treaty, which bans nuclear explosions "by everyone, everywhere", enters into force.

The Commision notes that four radioxenon isotopes are possible indicators of a nuclear explosion and may provide forensic evidence for analysts. These analysts track airborne radioxenon through the International Monitoring System.

To date the CTBT has been signed by 184 countries and 167 have also ratified it, including France, Russia and the UK. However, it cannot enter into force until it has also been signed and ratified by specific nuclear technology holder countries, including China, Egypt, India, Iran, Israel, North Korea, Pakistan and the USA. India, North Korea and Pakistan have yet to sign it.

Photo: The ANSTO nuclear medicine facility in Lucas Heights, Australia. Credit: ANSTO