Neutron Imaging of Irradiated Nuclear Fuel at Idaho National Laboratory

Dr. Aaron E. Craft
Idaho National laboratory

Idaho National Laboratory (INL) is actively pursuing multiple efforts to develop and evaluate a variety of nuclear fuels, including accident tolerant fuels, transmutation fuels, reduced-enrichment fuels for research reactors, high-burnup fuels, and others. As part of this evaluation, these fuels are irradiated and then subjected to post irradiation examination (PIE) to assess the irradiation performance of the nuclear fuel. The PIE includes both non-destructive and destructive evaluations that can provide insight with respect to the overall behavior and performance of the fuel, as well as scientific data to support the modeling and simulation efforts.

Neutron radiography is one of the first evaluations for irradiated fueled experiments once they arrive at the Hot Fuel Examination Facility (HFEF). Neutron radiography provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. The Neutron Radiography reactor (NRAD) sits beneath the HFEF main hot cell and provides a thermal neutron source for neutron radiography using two neutron beamline facilities. NRAD currently uses the foil-film transfer technique for imaging fuel, which is time consuming but provides high spatial resolution and is insensitive to the radiation emitted from the fuel.

Researchers at INL, in collaboration with universities and industry, are pursuing efforts to advance the neutron imaging capabilities available at NRAD to include advanced digital neutron imaging systems that are capable imaging highly-radioactive objects. The unique attenuation properties make neutron imaging a valuable research tool for many applications beyond nuclear fuels. INL researchers are also developing neutron imaging systems at NRAD that will include large-area, real-time, and high-resolution neutron imaging capabilities for non-radioactive objects.

This presentation describes the current neutron radiography facilities and capabilities available at INL, planned upgrades to the neutron imaging systems, and new capabilities being developed at INL.