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Radiation Monitoring System Upgrade for the NBSR



James R. Whipple, Dagistan Sahin, Yehonatan Zino


The Radiation Monitoring System (RMS) at the NIST Center for Neutron Research (NCNR) Reactor (National Bureau of Standards Reactor – NBSR) has demonstrated reliability issues due to outdated hardware and lack of vendor support. The existing radiation monitors connect to a controller in the control room through RS485 communication protocol, which is then displayed on an LCD segmented display to operators. If the value is over its pre-defined threshold, the machine actuates an annunciator to indicate an unsafe condition. Over time, multiple RMS devices have gone out of commission, being unable to communicate with the centralized controller, and localized monitors had to be used to monitor area radiation safety. The original manufacturer of the system has since gone out of business and attempts to repair and replace broken components have been fruitless. It is due to these reasons that a new system had been engineered using modern control and communication systems integrated into the NBSR Control Console Upgrade. The new RMS installation will be completed in three phases. The first phase consists of an update to the Operation Control Panel located on the control console. The Operation Control Panel is the centralized location where operators can interact with the system and evaluate radiation hazards. It consists of 3 Nuclear-grade digital bar graph indicators, a touchscreen SCADA HMI to monitor and indicate the value of the Area Radiation Monitors, and a touchscreen Digital Recorder which stores monitored values of all Radiation Monitors.
Proceedings Title
International Conference on Nuclear Engineering
Conference Dates
May 21-26, 2023
Conference Location
Kyoto, JP
Conference Title
30th International Conference on Nuclear Engineering (ICONE30)


Radiation Monitoring, Ethernet communication, Modbus, Fault Mode, Effects, and Analysis, Analog to Digital Upgrade


Whipple, J. , Sahin, D. and Zino, Y. (2023), Radiation Monitoring System Upgrade for the NBSR, International Conference on Nuclear Engineering, Kyoto, JP, [online], (Accessed April 13, 2024)
Created May 25, 2023, Updated March 15, 2024