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Agencies study plutonium power plan

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The U.S. Department of Energy has scheduled public meetings on a proposal to consolidate the operations required to support the production of radioisotope power systems at the new Idaho National Laboratory at Idaho Falls, Idaho.

The Energy Department and NASA are advancing the expanded use of radioisotope power systems for future space ventures to the moon, Mars and beyond.

NASA has used radioisotope thermal generators, or RTGs, to energize a variety of probes, including the Galileo mission to Jupiter as well as the Cassini spacecraft now circling Saturn. This type of power technology is used on spacecraft because they provide electricity and heat over long periods of time without any maintenance.

Nuclear power is also essential to the New Horizons mission to Pluto, which is now being built and is due for a sendoff in 2006.

The Energy Department announced the environmental review of the proposed consolidation of nuclear operations related to the production of radioisotope power systems, or RPS — technology that enables space exploration projects as well as certain national security-related missions.

RPS is a unique technology for missions that require a long-term, unattended source of heat and/or electrical power for use in harsh and remote environments — such as deep space. The plutonium-238 in these units serves as the source for generating heat and electricity. The heat source can be used directly to warm critical spacecraft components.

Consolidate operations
Currently, the Energy Department plans to produce RPS in support of the government's overnment national security and space exploration missions at three geographically separate sites: the Oak Ridge National Laboratory in Tennessee and Los Alamos National Laboratory in New Mexico, in addition to the Idaho site. The department is proposing to consolidate all these operations at one highly secure site to increase the security of the nuclear material while reducing costs and risks from transportation.

According to the Energy Department: “The proposed consolidation of these operations, which includes production, purification and encapsulation of plutonium-238 (Pu-238), would be consistent with DOE's approach on consolidating nuclear materials, increasing the security of nuclear materials, and reducing risks associated with transportation of nuclear materials. The EIS [environmental impact statement] will analyze all reasonable alternatives for the consolidation of the RPS operations as well as the no-action alternative."

Under the "no action" alternative, the Energy Department would continue the RPS production operations as they currently exist.

Last October, Deputy Secretary of Energy Kyle McSlarrow announced the commissioning of the new radioisotope facility, known as the Space and Security Power Systems Facility, at Idaho’s Argonne National Laboratory-West site.

The new facility will assemble and test radioisotope power systems that the Energy Department builds for NASA and various national security agencies.  When the new facility begins operations later this year, its first major mission will be to assemble, test and deliver a power system to NASA for the 2006 New Horizons mission.

“More than 40 of DOE’s radioisotope power systems have flown on spacecraft, beginning in the 1960s with the manned missions to the moon and continuing today with the three systems providing electricity to the Cassini spacecraft now orbiting Saturn,” Deputy Secretary McSlarrow said. “The completion of this facility is an important new mission for Idaho, and we look forward to continuing our work with NASA.”

Public meetings
These radioisotope power systems are effective for use in space exploration because they can safely and reliably produce electricity 24 hours a day, seven days a week for several decades. They are particularly advantageous when distances from the sun are so great that solar panels would not be feasible.

Composed of two principal parts — a heat source and an energy conversion system — they work by converting the heat from radioactive decay of plutonium-238 into electricity using a thermocouple. The largest of the radioisotope power systems are the three that are currently onboard the Cassini spacecraft, each system producing about 285 watts of electricity, roughly equivalent to three 100-watt light bulbs. DOE’s power systems have proven to be very reliable and durable:  the Voyager 1 spacecraft, launched in 1977, was still sending signals back to Earth when it left the solar system late last year.

Several of the meetings have already taken place. Future public meetings are slated for Dec. 13 at the Los Alamos County Golf Course in Los Alamos, N.M.; Dec. 15 at the Oak Ridge Comfort Inn in Oak Ridge, Tenn.; and Dec. 17 at the Hyatt Regency on Capitol Hill in Washington.

More information can be found on the Internet at