Advanced Test Reactor and Experiment Research Program

Frances M. Marshall
Manager, ATR Experiment Program

National Laboratory

The Advanced Test Reactor (ATR), at the Idaho National Laboratory (INL), is one of the world’s premier test reactors for providing the capability for studying the effects of intense neutron and gamma radiation on reactor materials and fuels. The physical configuration of the ATR, a 4-leaf clover shape, allows the reactor to be operated at different power levels in the corner “lobes” to allow for different testing conditions for multiple simultaneous experiments. The combination of high flux (maximum thermal neutron fluxes of 1015 neutrons per square centimeter per second and maximum fast [E>1.0 MeV] neutron fluxes of 5x1014 neutrons per square centimeter per second) and large test volumes (up to 48” long and 5” diameter) provide unique testing opportunities.  For future research, some ATR modifications and enhancements are currently planned.  In 2007 the US Department of Energy designated the ATR as a National Scientific User Facility (NSUF) to facilitate greater access to the ATR for material testing research by a broader user community.  This presentation provides more details on some of the ATR capabilities, key design features, and experiment programs. A cross section of the ATR is shown below.