Test Reactor Area west of Idaho Falls is home to the Advanced Test Reactor.

It's been 40 years since construction began on the Advanced Test Reactor at the U.S. Department of Energy's Idaho National Engineering and Environmental Laboratory, and 37 years since it went critical. The ATR has produced much of the world's data on material and fuel response to the high radiation environments of power reactors.

But, even with nearly four decades of operation, the ATR has years of service to come. The reactor has a growing customer base, will play a key part in developing the next phase of nuclear power reactors, and will contribute to this nation's space exploration efforts.

The ATR was originally designed to study the effects of intense radiation on reactor material and fuels. Under bombardment by neutrons and gamma rays within a reactor, materials are altered, becoming brittle, swelling or experiencing other physical changes.

The Advanced Test reactor's unique four-leaf-clover core design provides nine main test spaces at 250 MWTH.

The reactor is a virtual "time machine." Part of the uniqueness of the ATR rests with its capability to produce an extremely high neutron flux that duplicates years of exposure of materials experienced in a commercial nuclear reactor's radiation environment in a matter of weeks or months. Its core design allows many experiments to be conducted simultaneously, with each experiment receiving a different and carefully controlled level of radiation.

For many years, the reactor's primary customer has been the U.S. Navy, which used the ATR to test materials and fuels used in the reactors that powered by United States' nuclear fleet. Results of those tests have allowed the Navy to maintain a high degree of safety and to extend the "at-sea" life of nuclear-powered vessels.

While the Navy work continues, new national and international clients are using the ATR. The reactor is attracting new customers and support for the Department of Energy's Generation IV mission.

British Nuclear Group, Reactor Sites, in the United Kingdom has been using the ATR for irradiation/oxidation experiments designed to produce graphite representative of an end-of-life Magnox nuclear power station.

M.P. Metcalfe, Ph.D., project manger, says, "The uniqueness and complexity of the experiment presented a significant challenge for both the INEEL and British Nuclear Group project teams. Successful achievement of all the project objectives can be attributed to the skill and professionalism of the INEEL team, and to the highly effective working relationship established between INEEL and British Nuclear Group."

The Japanese nuclear industry is using the ATR to irradiate steel specimens to test welding techniques the Japanese use to repair reactor vessels in pressurized water reactors.

The INEEL's Advanced Test Reactor is the most powerful test reactor operating in the United States.

The ATR continues its long-time production of isotopes. Working with International Isotopes Inc., Idaho Falls, ATR is producing cobalt-60. One of cobalt-60's uses is in a medical device used for precise treatment of otherwise inoperable vascular deformities and brain tumors.

Steve Laflin, president of International Isotopes, says "the U.S. would be in a position of total dependence on foreign suppliers were it not for our production of cobalt-60 in the ATR."

In 2000, the U.S. Department of Energy initiated the Generation IV International Forum. Under the GIF, a group of 11 nations and organizations is exploring six concepts of future nuclear power reactor designs. The INEEL and Argonne National Laboratory are also leading a U.S. effort to a next generation reactor that can co-produce electricity and hydrogen. The ATR is irradiating fuels and materials for the next generation of reactors.

Finally, the ATR will provide irradiation services for the nation's Vision for Space Exploration. In cooperation with the Oak Ridge National Laboratory High Flux Isotope Reactor, ATR will produce Pu-238 for use in radioisotopic thermoelectric generators (RTGs). The RTGs provide the National Aeronautics and Space Administration with units to produce power needs in space vehicles. Also, the ATR will test reactor fuels for future space reactors that will provide space propulsion and power vehicles that will roam the surface of planets.