Radiation Monitoring System

Indoor Radiation Monitors

1)Gamma Radiation Monitors
Fixed-position gamma monitors are installed in many areas to warn of increased radiation levels.
2) Neutron Monitors
The monitors are set in the reactor rooms of the KUR and KUCA to measure external dose rates by neutrons.
3) Dust Monitors
To monitor the concentration of anthropogenic radioactivity in the exhaust gas from both the reactor buildings and radiation facilities, dusts are collected on a filter paper and measured continuously for alpha, beta and gamma emitters.
4) Water Monitors
Water monitors are installed to observe the radioactivity level in primary/secondary coolant waters of the reactor.
5) Hand-Foot-Cloth Monitors
The monitors set at the exit of corridor will detect small quantities of beta/gamma contamination on shoes, clothing, etc. Nobody goes out of the controlled area without checking contamination by this instrument.

Indoor Radiation Monitors

Radiation monitoring panel for KUR

Outdoor Radiation Monitors

1) Monitoring posts
Monitoring posts with a NaI probe are installed at five locations near the border of KURRI to observe and record external gamma-ray dose rates continuously.
2) Monitoring Stations
At four sites in the vicinity of KURRI, i.e. Wada, Shimogawaraya, Ichiba, and Hineno, gamma-ray monitors equipped with data recorders and data transmission systems are set. Monitoring data are transmitted to the meteorological observatory in the KURRI site by a telemeter system.
Most of signals obtained by the monitoring system mentioned above are transmitted to the radiation control room and radiation levels are watched to cope with any incidents.
3) Meteorological Observatory
Data observed on various meteorological factors such as wind direction, wind speed, and solar radiation are accumulated and utilized to estimate the radiation dose due to airborne radioactivities either chronically or accidentally released from nuclear and radiation facilities.

Low background gamma-ray emitter analyzing system with shielding and sample changer.

Monitoring post


1) Low Background Ge(Li) Instrument
Radionuclide concentrations in various field samples such as soils, vegetables, surface water, sea water, river and lake sediments are determined by using a gamma-ray emitter analysis system equipped with a Ge(Li)-detector.
2) Whole Body Counter
The content of radioactivity inhaled/ingested in human body is analyzed to assess the internal exposure dose by the instrument with a NaI detector in a shielding condition.
3) Survey Maters
Appropriate survey meters capable of detecting and measuring alpha, beta, gamma-ray and neutron radiation are available at KURRI.
4) Glass Badge
A glass badge is mounted on a body and changed monthly to monitor the external radiation dose.