List of Findings and Recommendations

Given below is a complete list of the committee’s findings and recommendations, in the order in which they appear in the report.


FINDING. Production of 238Pu. The United States has not produced 238Pu since the Department of Energy shut down its nuclear weapons production reactors in the late 1980s.


FINDING. Importance of RPSs. RPSs have been, are now, and will continue to be essential to the U.S. space science and exploration program.


FINDING. Plutonium-238 Supply. Plutonium-238 is the only isotope suitable as an RPS fuel for long-duration missions because of its half-life, emissions, power density, specific power, fuel form, availability, and cost. An assured supply of 238Pu is required to sustain the U.S. space science and exploration program.


FINDING. Roles and Responsibilities. Roles and responsibilities as currently allocated between NASA and the Department of Energy are appropriate, and it is possible to address outstanding issues related to the short supply of 238Pu and advanced flight-qualified RPS technology under the existing organizational structures and allocation of roles and responsibilities.


FINDING. RPS Nuclear Safety. The U.S. flight safety review and launch approval process for nuclear systems comprehensively addresses public safety, but it introduces schedule requirements that must be considered early in the RPS system development and mission planning process.


FINDING. Foreign Sources of 238Pu. No significant amounts of 238Pu are available in Russia or elsewhere in the world, except for the remaining 238Pu that Russia has already agreed to sell to the United States. Procuring 238Pu from Russia or other foreign nations is not a viable option.


FINDING. Domestic Production of 238Pu. There are two viable approaches for reestablishing production of 238Pu, both of which would use facilities at Idaho National Laboratory and Oak Ridge National Laboratory. These are the best options, in terms of cost, schedule, and risk, for producing 238Pu in time to minimize the disruption in NASA’s space science and exploration missions powered by RPSs.


FINDING. Alternate Fuels and Innovative Concepts. Relying on fuels other than 238Pu and/or innovative concepts for producing 238Pu as the baseline for reestablishing domestic production of 238Pu would increase technical risk and substantially delay the production schedule. Nevertheless, research into innovative concepts for producing 238Pu, such as the use of a commercial light-water reactor, may be a worthwhile investment in the long-term future of RPSs.


FINDING. Current Impact. NASA has already been making mission-limiting decisions based on the short supply of 238Pu.


FINDING. Urgency. Even if the Department of Energy budget for fiscal year 2010 includes funds for reestablishing 238Pu production, some of NASA’s future demand for 238Pu will not be met. Continued delays will increase the shortfall.


HIGH-PRIORITY RECOMMENDATION. Plutonium-238 Production. The fiscal year 2010 federal budget should fund the Department of Energy (DOE) to reestablish production of 238Pu.

  • As soon as possible, the DOE and the Office of Management and Budget should request—and Congress should provide—adequate funds to produce 5 kg of 238Pu per year.

  • NASA should issue annual letters to the DOE defining the future demand for 238Pu.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 31
List of findings and recommendations FINDING. Domestic Production of 238Pu. There are two Given below is a complete list of the committee’s findings viable approaches for reestablishing production of 238Pu, and recommendations, in the order in which they appear in the report. both of which would use facilities at Idaho National Labora- tory and Oak Ridge National Laboratory. These are the best FINDING. Production of 238Pu. The United States has not options, in terms of cost, schedule, and risk, for producing produced 238Pu since the Department of Energy shut down its 238Pu in time to minimize the disruption in NASA’s space nuclear weapons production reactors in the late 1980s. science and exploration missions powered by RPSs. FINDING. Importance of RPSs. RPSs have been, are now, FINDING. Alternate Fuels and Innovative Concepts. Relying on fuels other than 238Pu and/or innovative con- and will continue to be essential to the U.S. space science cepts for producing 238Pu as the baseline for reestablishing and exploration program. domestic production of 238Pu would increase technical risk FINDING. P lutonium-238 Supply. P lutonium-238 is and substantially delay the production schedule. Neverthe- less, research into innovative concepts for producing 238Pu, the only isotope suitable as an RPS fuel for long-duration missions because of its half-life, emissions, power density, such as the use of a commercial light-water reactor, may be specific power, fuel form, availability, and cost. An assured a worthwhile investment in the long-term future of RPSs. supply of 238Pu is required to sustain the U.S. space science FINDING. C urrent Impact. NASA has already been and exploration program. making mission-limiting decisions based on the short supply FINDING. Roles and Responsibilities. Roles and respon- of 238Pu. sibilities as currently allocated between NASA and the FINDING. Urgency. Even if the Department of Energy Department of Energy are appropriate, and it is possible to address outstanding issues related to the short supply of budget for fiscal year 2010 includes funds for reestablish- 238Pu and advanced flight-qualified RPS technology under ing 238Pu production, some of NASA’s future demand for 238Pu will not be met. Continued delays will increase the the existing organizational structures and allocation of roles and responsibilities. shortfall. FINDING. RPS Nuclear Safety. The U.S. flight safety HIGH-PRIORITY RECOMMENDATION. Plutonium- 238 Production. The fiscal year 2010 federal budget should review and launch approval process for nuclear systems comprehensively addresses public safety, but it introduces fund the Department of Energy (DOE) to reestablish produc- tion of 238Pu. schedule requirements that must be considered early in the RPS system development and mission planning process. • As soon as possible, the DOE and the Office of Man- FINDING. Foreign Sources of 238Pu. N o significant agement and Budget should request—and Congress amounts of 238Pu are available in Russia or elsewhere in the should provide—adequate funds to produce 5 kg of world, except for the remaining 238Pu that Russia has already 238Pu per year. agreed to sell to the United States. Procuring 238Pu from • NASA should issue annual letters to the DOE defining the future demand for 238Pu. Russia or other foreign nations is not a viable option. 

OCR for page 31
 RADIOISOTOPE POWER SYSTEMS FINDING. Programmatic Balance. B alance within RECOMMENDATION. Technology Plan. NASA should NASA’s RPS program is impossible given the current (fiscal develop and implement a comprehensive RPS technology year 2009) budget and the focus on development of flight- plan that meets NASA’s mission requirements for RPSs while minimizing NASA’s demand for 238Pu. This plan ready ASRG technology. However, NASA is moving the ASRG project forward, albeit at the expense of other RPS should include, for example: technologies. • A prioritized set of program goals. FINDING. Multi-Mission Radioisotope Thermoelectric • A prioritized list of technologies. Generators. It is important to the national interest to main- • A list of critical facilities and skills. tain the capability to produce Multi-Mission Radioisotope • A plan for documenting and archiving the knowledge Thermoelectric Generators, given that proven replacements base. do not now exist. • A plan for maturing technology in key areas, such as reliability, power, power degradation, electrical inter- RECOMMENDATION. M ulti-Mission Radioisotope faces between the RPS and the spacecraft, thermal Thermoelectric Generators. NASA and/or the Department interfaces, and verification and validation. of Energy should maintain the ability to produce Multi- • A plan for assessing and mitigating technical and sched- Mission Radioisotope Thermoelectric Generators. ule risk.,., FINDING. Flight Readiness. NASA does not have a HIGH-PRIORITY RECOMMENDATION. ASRG Development. NASA and the Department of Energy (DOE) broadly accepted set of requirements and processes for demonstrating that new technology is flight ready and for should complete the development of the Advanced Stirling committing to its use. Radioisotope Generator (ARSG) with all deliberate speed, with the goal of demonstrating that ASRGs are a viable RECOMMENDATION. Flight Readiness. The RPS pro- option for the Outer Planets Flagship 1 mission. As part gram and mission planners should jointly develop a set of this effort, NASA and the DOE should put final design of flight-readiness requirements for RPSs in general and ASRGs on life test as soon as possible (to demonstrate reli- Advanced Stirling Radioisotope Generators in particular, as ability on the ground) and pursue an early opportunity for well as a plan and a timetable for meeting the requirements. operating an ASRG in space (e.g., on Discovery 12).