Self Powered Krypton-85 Wireless Sensor for Fuel Cycle Gas Emissions

Period of Performance: 01/01/2014 - 12/31/2014


Phase 1 STTR

Recipient Firm

Ayers Group
910 Princeton-Kingston Rd
Princeton, NJ 08540
Principal Investigator, Firm POC

Research Institution

Princeton University
P. O. Box 451
Princeton, NJ 08543


The Office of Nuclear Energy, fuel cycle research and development program, requires improved radioisotope detectors for spent fuel rod monitoring and process control. Processing spent fuel rods releases large amounts of the fission by-product gas krypton-85 (Kr-85). This beta emitting radioisotope gas has a 10.7 year half-life and must be captured and stored for up to 100 years. The health hazards of Kr-85 led the Environmental Protection Agency to place limits on its emission from spent fuel processing and gas storage sites. The EPA emission limit is 50,000 Curies of Kr-85 per gigawatt-year for each commercial nuclear power plant that produces the spent fuel. A spent fuel facility that processes 200 tons of fuel per year will generate about two million Curies of Kr-85. To prevent release of this Kr-85 into the atmosphere a robust, accurate Kr-85 detector is needed to monitor and document the capture, separation, and storage of the gas. In Phase I, a portable, self-powered, wireless detector is developed for Krypton-85 The detector utilizes the Kr-85 beta emission to generate and transmit a high frequency signal proportional to the Kr-85 concentration. Phase I tasks focus on computer simulation, fabrication and testing of the detector. Development of the Kr-85 detector will greatly improve the monitoring of the Kr-85. Prevention of Kr-85 release into the atmosphere and the ability to monitor Kr-85 stored in cylinders for decades supports EPA’s emission regulations that protect the public from this 10 year half-life radioactive gas. Specific groups within the Federal government and commercial sector that would benefit from the Kr-85 detector include Oak Ridge, Idaho, Hanford,and Savannah River National Laboratories and commercial nuclear reactor facilities. If successful, the commercial detector, display and software instrument will provide an inventory record of Kr-85 concentrations at processing and storage sites.. This detailed record verifies that EPA emission limits have not been violated. There is a worldwide market for the detector at spent fuel processing and storage sites in the U.S., France, Russia, Japan, and China