Hybrid Diamond Detector for Nuclear Reactor Monitoring

Safe operation of nuclear reactors is key for successful use of nuclear energy and prevention of potential accidents. Multiple physical processes for reactor save operations are coupled together, including heat generation, heat transfer, and radiation level. Monitoring of temperature and neutron flux inside the reactor provides critical operational and safety information. Reactor monitoring requires reliable local radiation and temperature sensors able to measure both parameters simultaneously, stable in the high temperature and radiation environment, and having a fast time response. Diamond has a unique combination of extreme radiation tolerance and high temperature stability which makes it an ideal material for in-core radiation and temperature solid state sensors. Diamond radiation detectors have been used for detection of many types of radiation including alpha particles, neutrons, protons, electrons, gamma and X-rays. Diamond thermistors, when compared to popular thermocouple sensors, have about the same temperature range, but are more sensitive, much faster, and often have better radiation tolerance. Recent progress in synthetic diamond growth significantly improved its electronic quality and reduced the cost thus making diamond devices increasingly commercially attractive. Applied Diamond, Inc. proposes to leverage its prior work in using detector grade CVD diamond for particle detectors to make and characterize a hybrid single chip diamond radiation detector-thermistor (DRDT) from electronic grade single crystal CVD diamond. The suggested DRDT would allow simultaneous monitoring of the radiation (neutrons, alpha particles, etc.) and temperature at the same location inside the nuclear reactor. The DRDT will represent a significant improvement over common radiation detectors since the temperature correction of the detector’s signal can be based on the measured temperature of the detector. The proposed approach has the potential for a significant impact on in-core nuclear reactor monitoring and improvement of reactor safety. This technology will also advance the use of radiation tolerant diamond devices in future nuclear energy, high energy physics, and space experiments. Development of a DBPD will address current needs in nuclear reactor monitoring applications at Idaho National Laboratory and could be useful at other DOE nuclear reactor facilities as well.