Astronomy and Astrophysics Advisory Committee Urges Restart of Pu-238 Production

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Publication date: 
24 November 2010

One  of the many issues Congress must deal with when it returns to Washington next  week is the FY 2011 request by the Obama Administration to restart the  production of Pu-238, the fuel used in radioisotope thermoelectric generators  in deep space probes.  After last year’s rejection  by Congress of the request to fund the production of this isotope in the  Department of Energy appropriations bill, the Administration has now proposed  that the $30 million needed to start this process be equally divided between  DOE and NASA. 

Although  the details of the FY 2011 House Energy and Water Development Appropriations  Bill are not yet known, it appears that the subcommittee drafting this measure  included the requested $15 million in the DOE Nuclear Energy request.  Senate appropriators rejected the DOE funding  request, stating in its committee report, “As NASA will be the only user of  Pu-238, the Committee believes NASA should pay for the entire service through a  similar work for others arrangement that DOE has with the Department of  Homeland Security and other government agencies.”

On  November 18, the Astronomy and Astrophysics Advisory Committee   sent a letter regarding Pu-238 production to NASA Administrator Charles Bolden,  Energy Secretary Steven Chu, Senate Commerce, Science, and Transportation  Committee Chairman John Rockefeller (D-WV), House Science and Technology  Committee Chairman Bart Gordon (D-TN), Energy Undersecretary for Science Steven  Koonin, Office of Science Director William Brinkman, and NASA Associate  Administrator Edward Weiler.  Expressing  concern that a further delay in Pu-238 production will hinder outer solar  system planetary missions and future astrophysics missions, the letter urges “prompt action be taken and appropriate budgetary resources  be identified through cooperative coordination between DOE, NASA, and, if  applicable, other federal agencies (i.e., NNSA, Dept. Homeland Security), to  enable the Pu-238 project production restart for deep space mission  applications.”

The  full text of the letter follows:

“Dear Mr. Bolden, Dr. Chu, Chairman  Rockefeller, Chairman Gordon, Dr. Koonin, Dr. Brinkman, and Dr. Weiler:

“The Astronomy & Astrophysics  Advisory Committee (AAAC) is charged in part to assess and make recommendations  regarding the status of activities of the NSF, NASA, and DOE as they relate to  cooperative national programmatic activities in astronomy and astrophysics and  space exploration. At its 2010 October 7-8 meeting, the AAAC was briefed on the  Pu-238 production restart project status, an activity involving NASA and DOE  coordination.

“The manmade radioactive isotope Pu-238  can be used to generate electricity due to the heat emitted by its radioactive decay.  Encapsulated in a radioisotope thermoelectric generator (RTG), this vital  element is necessary for powering probes sent to the outer reaches of the solar  system, a research area where the US can clearly claim significant  international leadership.

“A National Academies Report, entitled  “Radioisotope Power Systems: An Imperative for Maintaining U.S. Leadership in Space  Exploration,” issued in 2009, articulated the critical need for this element to  maintain US leadership in space exploration. Among the findings and  recommendations made in this report were: a) immediate action is required to  begin producing Pu-238 as it will take about 8 years from initiation to full  production of the required 5 kg/year; and b) cooperation between the DOE and  NASA, with support from the President and funding from Congress, would be  required to fulfill this vital need.

“The AAAC is concerned that delays in  the restart of this production effort hinder not only the ability for the US to  conduct NASA planetary missions to the outer solar system, but may well impede  development and implementation of future astrophysics missions requiring  significant power resources operating in deep space beyond Earth orbit. Delay  of restart adds increased cost and schedule delays to the development of NASA  planetary science missions. Reliance on Pu-238 from international sources, such  as the Russians, is challenging. The AAAC is concerned that resumption of  domestic Pu-238 RTG production has not yet occurred and that the dialogue  necessary to effect resumption has been inconclusive.

“The AAAC urges that, in consultation  with Congress, prompt action be taken and appropriate budgetary resources be identified  through cooperative coordination between DOE, NASA, and, if applicable, other  federal agencies (i.e., NNSA, Dept. Homeland Security), to enable the Pu-238  project production restart for deep space mission applications.

“Sincerely yours, on behalf of the  Committee,

Kim Griest,     Chair, Astronomy and Astrophysics  Advisory Committee”