15 February 2010
NASA, U.S. Energy Department Would Split Cost of Restarting Pu-238 Production
By Brian Berger
Space News


NASA's Mars Science Laboratory (MSL) rover.
Credit: NASA/JPL-CalTech artist's concept

WASHINGTON — The White House is proposing that NASA and the U.S. Department of Energy split the cost of restarting domestic production of plutonium-238 for NASA deep space missions and for national security applications.

The two agencies are asking the U.S. Congress for a combined $30 million for 2011 to begin a multiyear effort to start producing the nonweapon-grade material at U.S. nuclear laboratories for the first time in decades.

Congress last year denied President Barack Obama’s $30 million request for the Pu-238 restart process, saying it needed a more detailed start-up plan specifying NASA’s contributions to an effort expected to take six to seven years and cost $150 million or more.

NASA officials said Feb. 1 that the agency’s $19 billion budget request for 2011 provides for restarting Pu-238 production with the Department of Energy but gave no details of what NASA’s role would be.

The Department of Energy’s 2011 budget request, also released Feb. 1, said the department’s Office of Nuclear Energy, Science and Technology is asking Congress for $15 million “as part of a 50/50 cost share project with [NASA] to begin reestablishing domestic capability to produce Plutonium (Pu)-238 for use in radioisotope power systems for NASA missions and national security applications.”

NASA has yet to release a detailed budget proposal. A 22-page PowerPoint presentation posted on the agency’s Web site Feb. 1, however, appears to indicate NASA’s share of Pu-238 restart costs would be included in its Planetary Science Division’s proposed $1.48 billion budget for 2011.

Ralph McNutt, a planetary scientist who co-chaired a National Research Council panel that called last year for re-establishing domestic Pu-238 production capability, told Space News in a Feb. 9 e-mail he was hopeful that the cost-sharing arrangement would satisfy House and Senate lawmakers who objected to the lack of details included in Obama’s 2010 proposal. “My understanding is that this should be the case,” McNutt wrote.

Assuming Congress approves the funding this year, McNutt said, Pu-238 production could be “fully up and running” by the end of 2017. “[A]nd that would be a very good thing because it would ensure that the robotic side of scientific exploration of space can continue to open our eyes to new knowledge of the world around us,” he wrote.

NASA has relied on plutonium-238 for decades to fuel radioisotope power systems, long-lasting spacecraft batteries that transform heat from the decaying plutonium into electricity. The Pluto-bound New Horizons probe launched in 2006 has 11 kilograms of the material on board, and the Mars Science Laboratory rover slated to launch in late 2011 will carry 3.5 kilograms.

NASA’s 2011 budget request also includes an unspecified amount of funding to begin development of a flight-ready Advanced Stirling Radioisotope Generator (ASRG) that could be ready to launch in 2014 or 2015. ASRGs are roughly four times more efficient than today’s radioisotope power systems, but are not yet flight-proven. NASA hopes to fly an ASRG for the first time in 2016 as part of its Discovery program of competitively selected planetary missions.

The United States stopped producing plutonium-238 in the late 1980s when it shut down the Department of Energy’s Savanna River Site in South Carolina for safety reasons. While U.S. nuclear laboratories remain able to process and package the material for use in radioisotope power systems, the Department of Energy has been meeting NASA’s demand for years from a dwindling stockpile supplemented by periodic purchases from Russia’s shrinking supply.

Russia, however, informed the Department of Energy last fall that it wants to renegotiate an agreement that calls for delivering a total of 10 kilograms of plutonium-238 to the United States in 2010 and 2011. A Department of Energy official told Space News in December that the department was working with other U.S. government agencies to decide what to do.

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