Of current interest: Materials testing reactor tests effects of neutron radiation on materials

The Materials Testing Reactor (MTR), a recent development at the Atomic Energy Commission´s National Reactor Testing Station in Idaho, has the highest neutron flux of any reactor now in existence. Thirty-thousand kw of heat are produced within a space about the size of 2 large suitcases. To provide a maximum density of both fast and thermal neutrons, the Uranium-235 in the MTR must fission at a high rate, with the release of high power per gram of fuel. A flow of over 300 gallons of water per second is needed to remove the heat.