With the 2020 Olympics and Paralympics in Tokyo just three years away, the government is stepping up efforts to prevent terrorist attacks using nuclear and other radioactive materials.
The Japan Atomic Energy Agency has developed a device capable of detecting nuclear materials during airport baggage screening and is enhancing its nuclear forensics analytical technology.
“We want to improve deterrence against nuclear terrorism,” an agency official said.
At a meeting of the Education, Culture, Sports, Science and Technology Ministry in December, Mitsuru Uesaka, president of the Atomic Energy Society of Japan and a professor at the University of Tokyo, said it was important to “enhance nuclear security” ahead of the games.
There have been numerous incidents overseas involving attempts to smuggle nuclear materials.
In 1994, investigative authorities intercepted and seized illegally transferred nuclear material at Munich Airport in Germany. The material — mixed oxide fuel containing weapons-grade plutonium — was found on a Lufthansa flight from Moscow. Smugglers were arrested and the MOX fuel was later identified as having been used at a nuclear reactor in the former Soviet Union.
There are also fears that the radical militant group Islamic State might have made a “dirty bomb” capable of scattering radioactive materials. Unlike nuclear weapons, such devices can be made relatively cheaply without advanced skills.
To stop nuclear materials from entering Japan through airports, the agency developed a device to detect very small amounts of uranium concealed in luggage by irradiating luggage with a beam of neutrons. The result is available in less than a second.
Baggage screening at domestic airports usually uses X-rays, but an expert at the agency said conventional screening is not effective in detecting nuclear materials.
“X-rays can detect suspicious metal objects, but cannot tell whether objects are nuclear materials or not,” said Yosuke To, leader of the research group behind the project at the agency.
The agency has also been developing nuclear forensics capabilities through analyzing “nuclear fingerprints,” such as particles and isotopic compositions, of materials stored at facilities related to nuclear power generation in the country. The agency has been working on registering the data in a database as well.
These efforts are aimed at determining the point of origin and routes of transit involving nuclear or radioactive materials when such materials are illicitly removed, lost or stolen.
As of the end of 2015, there were 454 confirmed incidents around the world involving unauthorized possession of nuclear materials and related criminal activities, 762 incidents involving reported theft or loss of such materials, and 1,622 incidents involving other unauthorized activities and events related to such materials, according to an International Atomic Energy Agency report.
In one high profile incident in Japan, a former employee of an inspection company in Ichihara, Chiba Prefecture, stole iridium-192 and dumped it into a river in 2008.