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A look at the core of the NRAD. |
The reactor core is much like the reactors that many universities use in their nuclear studies. In fact, the reactor in NRAD came from the University of Puerto Rico. These reactors are very safe while giving people insights into the nature of matter.
NRAD's main function is to perform neutron radiographs of irradiated components. The NRAD facility provides the ability to neutron radiograph highly irradiated fuel elements, fuel subassemblies, and loop experiments without removing them from the main cell's argon atmosphere. This argon atmosphere is important because many objects which are radiographed will react chemically with air. For this reason, it is important to keep these things in an inert gas at all times. The second neutron radiography station is outside of the main cell and permits neutron radiography of either unirradiated or irradiated specimens without introducing them into the contaminated main cell.
Neutron radiographs are taken by placing the object in front of a neutron beam with a foil behind it. These foils absorb the neutrons that travel through the radiographed object. The neutrons from the neutron beam energize atoms in the foil. This foil is then placed against a standard piece of photograpic film. The energized atoms undergo radioactive decay, releasing energy in the form of invisible light rays. These rays interact with the photographic film in the same way that visible light rays interact with the film in an ordinary camera. The film is then developed like a standard negative.
Although neutron radiographs are generally taken of irradiated components, such as fuel elements, they can be taken of almost anything. Fragments from space shuttles were once analyzed for damage. Oysters affected by an oil spill were also radiographed to check for any residual contamination. Almost anything that can be x-rayed can be neutron radiographed.
NRAD has limited irradiation capabilities in the core. It has a water filled port at the center of the core, and a dry port at the edge of the core. NRAD also operates an MF Physics linear particle accelerator. This is currently used for non-destructive assaying of waste and and expended nuclear fuel.