Wireless Sensor Platform for Dry Spent Fuel Cask Monitoring

Reactor cores in commercial power plants produce spent nuclear fuel which is discharged every 3-4 years. There is currently a pressing need to safely store spent fuel for long periods (decades to centuries) using dry storage systems. Such storage requires monitoring to ensure safe conditions as the waste decays. The system must meet challenging requirements: operate at 200 C, withstand high radiation, have a long term power source, and communicate through the walls of the sealed cask. RMD will design a system that meets the requirements, which integrates a rad-hard radiation sensor, self-sustaining thermoelectric power supply, and a means for transmitting data through the steel walls of sealed waste storage casks. RMD will collaborate with the University of Tennessee in Knoxville and Areva Transnuclear Inc. During Phase I: 1) a self-powered wireless cask monitor system was designed and modeled, 2) a prototype thermoelectric generator system was designed and implemented, 3) a diamond 85Kr radiation sensors was fabricated, 4) a design for integrating the sensor with wireless communications technology was developed, 5) a test apparatus and prototype monitoring system was constructed, and 6) the transfer of monitoring data from inside a sealed metal container was demonstrated. During Phase II, RMD will determine designs and components needed for the power distribution and management, radiation sensor, temperature sensor, pressure sensor, micro-controller and data transmitter, verify the operation of the components in a relevant temperature and radiation environment, and build a prototype. The principal customer for our system is the DOE and its counterparts around the world. Oak Ridge National laboratory estimates the number of casks in the U.S. is growing at a rate of 200/year. The annual discharge of fuel assemblies from the world's nuclear reactors is estimated to be 10,500 MTU. The world-wide cumulative quantity of generated spent fuel is expected to be more than 445,000 tHM by the end of 2020, with the U.S. contributing 88,000 MTU. Based on these growth rates, we estimate that there is an annual need for approximately 1,000 dry cask storage systems on a worldwide basis. We estimate that a complete system that will meet DOE’s specifications will cost approximately $40,000. Therefore, the U.S. market is approximately $8 million and we estimate the worldwide market to be valued at $40 million annually. Nuclear waste storage cask, diamond radiation detector, wireless communication, ultrasonic transmission, thermoelectric generator, safeguards. This research will develop a long term solution for monitoring the condition and security of nuclear waste storage casks for periods of up to centuries.