Takasaki, Gunma

LocationTypeTreaty CodeStatus
Takasaki, GunmaRadionuclide StationRN38Certified
Takasaki, GunmaNoble Gas SystemCertified

Page 1 RN38

Radionuclide station RN38, Takasaki, Japan

Thumbnail profile: Takasaki

Situated on the Kanto Plain approximately 100 km northwest of Tokyo, Takasaki City covers an area of 330 km². It is a vibrant urban centre that embraces both the downtown commerce and industry and protects the natural peace and tranquility found in the rural Kurabuchi district. In January 2006 Takasaki City merged with other towns, forming the current city that is home to approximately 320,000 people.

Its proximity to Tokyo, only 50 minutes by bullet train, makes the city a strategic hub for transport and commerce. The city is also home to the Takasaki Advanced Radiation Research Institute and JAEA, the Japan Atomic Energy Agency, on the eastern outskirts of the city.

History and Geography

Daruma dolls at Shorinzan temple.

The remains of many ancient communities have been uncovered in Takasaki, proving that people thrived in the area more than 1,400 years ago. During the Edo period (1600-1868), Takasaki's role as a castle town led to an influx of merchants and an increase in the population.

Following the Second World War, Takasaki continued to grow as an industrial city with an extensive transportation system. Japan’s sophisticated bullet train lines make the city a gateway to the entire prefecture, as well as to the Sea of Japan and to the Japanese Alps. Takasaki City nurtures an international society where both the environment and city’s citizens co-exist in harmony together.


Station Location

Japan hosts 11 IMS facilities.

The IMS radionuclide station RN38 is located inside the premises of the Takasaki Advanced Radiation Research Institute of JAEA on the town’s eastern outskirts. This location is just nine km away from the coordinates originally established by the Treaty and was approved by the CTBTO.

A dedicated building was erected solely to host IMS equipment, including future Noble Gas equipment (see below). The building is within walking distance of the offices of the local station operator who is a JAEA staff member. The JAEA laboratory area is fenced off and of restricted access.

Learn more about how the radionuclide technology works.

The Fukushima Power Plant Accident

CTBTO radionuclide stations detected different radioactive isotopes from the damaged Fukushima power plant (in German by the German Federal Radiation Protection Agency)

The 11 March 2011 earthquake off the Japanese coast and the ensuing tsunami tragically killed tens of thousands of people and left the Fukushima power plant severely damaged. According to Japanese authorities, the CTBTO’s seismic and hydroacoustic stations in the region helped them to issue tsunami warnings within a few minutes, thus allowing many people to escape the tsunami.

Located around 250km to the southwest, RN38 is the IMS station closest to the Fukushima power plant. The station was one of the first IMS radionuclide stations to register radioactive particles such as Iodine-131 and Caesium-137 as well as the radioactive noble gas Xenon-133 emitted by the stricken plant. The station itself was affected by power outages shortly after the earthquake. Read more about the CTBTO’s Fukushima-related measurements.