Overview

[Background]With the in-depth exploration of space,the power supply requirements for energy supply are gradually increasing.Space nuclear reactor power supply stands out in the deep space exploration mission due to its advantages of passivity,long life and high reliability,hence heat pipe nuclear reactor has become the focus of research in the field of space nuclear reactor.[Purpose]This study aims to evaluate the progress and technology of heat pipe space nuclear reactor used as power supply.[Method]First of all,the conceptual design of heatpipe reactor in the early stage and its application in Kilopower was summarized.Then the details of heatpipe power system(HPS),the heatpipe-operated mars exploration reactor(HOMER),safe affordable fission engine(SAFE)and Kilopower were investigated with emphasis on the structure design,fuel selection,heatpipe arrangement and power design of each reactor.[Results]This survey provides ideas and references for future research and design of heatpipe space nuclear reactor power system.[Conclusions]The design of heatpipe reactor is highly flexible and innovative.The use of different alkali metal heat pipes and thermoelectric conversion methods has a direct impact on the system power and the quality of the entire system.The combination of heat pipe and various thermoelectric conversion methods can be attempted.

In October of 2002, The Power and Propulsion Office and The Risk Management Office of NASA Glenn Research Center in Cleveland, Ohio began developing the reliability, availability, and maintainability (RAM) engineering approach for the Space Nuclear Propulsion and Power Systems Project. The objective of the Space Nuclear Power and Propulsion Project is to provide safe and reliable propulsion and power systems for planetary missions. The safety of the crew, ground personnel, and the public has to be the highest priority of the RAM engineering approach for nuclear powered space systems. The project will require a top level reliability goal for substantial mission success in the range from 0.95 to 0.98. In addition, the probability of safe operation without loss of crew, vehicle, or danger to the public, cannot be less than 0.9999. The achievement of these operational goals will require the combined application of many RAM engineering techniques. These include: advanced reliability, availability, and maintainability analysis, probabilistic risk assessment that includes hardware, software, and human induced faults, accelerated life testing, parts stress analysis, and selective end to end sub-system testing. Design strategy must involve the selection of parts and materials specifically to withstand the stresses of prolonged operation in the space and planetary environments with a wide design margin. Interplanetary distances and resulting signal time delay drive the need for autonomous control of major system functions including redundancy management.

Space nuclear power and nuclear electric propulsion are considered important technologies for planetary exploration, as well as selected earth orbit applications. The Nuclear Electric Propulsion Space Test Program (NEPSTP) could provide an early flight demonstration of these technologies at relatively low cost through extensive use of existing Russian technology. The key element of Russian technology employed in the program is the Topaz II reactor. This space nuclear power system was built and flight qualified, though never tested in space, by the former Soviet Union.The NEPSTP is faced with many unique flight qualification issues. In general, the launch of a spacecraft employing a nuclear reactor power system will complicate many spacecraft qualification activities. However, the NEPSTP activities are further complicated because the reactor power system is a Russian design. Therefore, this program must deal not only with the unique flight qualification issues associated with space nuclear power, but also ...

Nuclear power sources have enabled or enhanced some of the most challenging and exciting space missions yet conducted, including missions such as the Pioneer flights to Jupiter and Saturn; the Voyager flights to Jupiter, Saturn, Uranus, and Neptune; the Apollo lunar surface experiments; the Viking Lander studies of Mars; the Ulysses mission to study the polar regions of the sun; and the Galileo mission to orbit Jupiter. This article surveys the early missions and continues to the present Galileo and Ulysses missions and provides a summary of the power technology that was used in each mission. Current activities aimed at improving the specific power and efficiency of space nuclear power sources are summarized. In addition to radioisotope power sources, this article surveys the U.S. space nuclear reactor program focusing on the flight of the SNAP-lOA reactor and the technology developed in the SP-100 space nuclear reactor power system program. The general attributes of space nuclear power sources are described and possible future applications are identified.

Life-cycle emission of oxidic gases from power-generation systems

There is a need in the space science community for nuclear‐powered electric propulsion systems to enable high‐value, deep space and planetary exploration. Certain missions are driven by once‐in‐a‐lifetime or highly infrequent occurrences that require the near‐term development of a flight‐capable nuclear space power and electric propulsion system in order to take advantage of the scientific opportunity. The broader applicability of Brayton power systems to the commercial and military aircraft markets has provided fertile ground for the continued development and implementation of new technologies applicable to a closed Brayton cycle space Power Conversion Unit (PCU). One concept for effectively achieving a near‐term Brayton space power capability is based on the development work associated with the Integrated Power Unit (IPU). This unit embodies the state of the art in turbomachinery, generators, bearing systems and electric power management and distribution capability that can readily be evolved into a closed Brayton cycle PCU. This paper provides an overview of aircraft‐based Brayton power system technologies, their implementation into the IPU and one approach for leveraging this capability into a near‐term closed Brayton cycle space power conversion unit.

During the 2000 presidential election, in that time before the September 11th terrorist attacks, the stump speeches of George W. Bush and his Democratic opponent, Al Gore, focused on protecting Social Security, saving American education, expanding Medicare, raising or lowering taxes, and readying the military. If science was mentioned at all, it was usually in the context of missile defense, global warming, or Gore’s role in creating the internet. With the exception of the debate over stem-cell research, science remains a background topic in the current campaign. Democratic candidate John Kerry has occasionally highlighted US science policy and used it against President Bush, charging that the administration has put politics and ideology ahead of science. “Let scientists do science again,” a headline on the Kerry election website says.Bush has responded, primarily through his science adviser, John Marburger, by pointing to the 44% increase in federal R&D since fiscal year 2001 and the record $132 billion in the administration’s FY 2005 R&D budget. “Kerry ignores President Bush’s record science investments,” reads a headline on the Bush reelection website.Kerry answers by noting that most of the R&D money is going for weapons systems and defense spending related to the war in Iraq, not basic science programs. Marburger and other administration officials point to several R&D initiatives, including new nanotechnology centers, the Moon/Mars space initiative, and the program to develop hydrogen fuel technology. In an effort to get the candidates to specifically address questions of interest to the science community, Physics Today has continued a tradition begun in 1976; it asked Bush and Kerry nine questions covering a range of science topics. Their answers, sometimes direct and sometimes vague, show fundamental differences on several key issues.On missile defense, Bush says his request of $10 billion in FY 2005 for development and deployment of such a system fulfills a pledge he made to the American people. Kerry says we should not be “falsely comforted by an untested and unproven defense system.”On global warming, Kerry talks of both near- and long-term programs to deal with the problem. Bush promotes his “comprehensive climate change strategy.” The candidates also address a host of other issues ranging from space exploration to energy policy. During the 2000 presidential election, in that time before the September 11th terrorist attacks, the stump speeches of George W. Bush and his Democratic opponent, Al Gore, focused on protecting Social Security, saving American education, expanding Medicare, raising or lowering taxes, and readying the military. If science was mentioned at all, it was usually in the context of missile defense, global warming, or Gore’s role in creating the internet. With the exception of the debate over stem-cell research, science remains a background topic in the current campaign. Democratic candidate John Kerry has occasionally highlighted US science policy and used it against President Bush, charging that the administration has put politics and ideology ahead of science. “Let scientists do science again,” a headline on the Kerry election website says.Bush has responded, primarily through his science adviser, John Marburger, by pointing to the 44% increase in federal R&D since fiscal year 2001 and the record $132 billion in the administration’s FY 2005 R&D budget. “Kerry ignores President Bush’s record science investments,” reads a headline on the Bush reelection website.Kerry answers by noting that most of the R&D money is going for weapons systems and defense spending related to the war in Iraq, not basic science programs. Marburger and other administration officials point to several R&D initiatives, including new nanotechnology centers, the Moon/Mars space initiative, and the program to develop hydrogen fuel technology. In an effort to get the candidates to specifically address questions of interest to the science community, Physics Today has continued a tradition begun in 1976; it asked Bush and Kerry nine questions covering a range of science topics. Their answers, sometimes direct and sometimes vague, show fundamental differences on several key issues.On missile defense, Bush says his request of $10 billion in FY 2005 for development and deployment of such a system fulfills a pledge he made to the American people. Kerry says we should not be “falsely comforted by an untested and unproven defense system.”On global warming, Kerry talks of both near- and long-term programs to deal with the problem. Bush promotes his “comprehensive climate change strategy.” The candidates also address a host of other issues ranging from space exploration to energy policy. 1Section:ChooseTop of page1 <<BushKerry2BushKerry3BushKerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerry Missile defense: The present administration is requesting more than $10 billion this year for development and deployment of a missile defense system. Many scientists say the system, given current and foreseeable technology, cannot be effective. What proof of effectiveness should be required before the system is fully deployed? Given the low-tech nature of terrorist attacks and the limited missile capabilities of North Korea and other hostile nations, does missile defense continue to be a wise investment? BushSection:ChooseTop of page1Bush <<Kerry2BushKerry3BushKerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryOur policy is to develop and deploy, at the earliest possible date, a weapons system that would defend the United States homeland against nuclear attack, including ballistic missile defenses drawing on the best technologies available. Early in my administration, I called for the examination of the full range of available technologies and basing modes for missile defenses that could protect the United States, our deployed forces, and our friends and allies.The FY 2005 Defense Appropriations Act provides $10 billion that I requested for systems to defend against the threat from ballistic missiles. Later this year, the first components of America’s missile defense system will become operational, and we are on schedule for the next stages of the project. My administration will develop and deploy the technologies necessary to protect our people, fulfilling a pledge I made to the American people more than four years ago.KerrySection:ChooseTop of page1BushKerry <<2BushKerry3BushKerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryA missile defense that works is a wise investment, but one that pours money into defenses at the expense of other immediate national security needs is not. And that’s what this administration has done. Missile defense should be one element of a comprehensive national security strategy. But a single-minded focus on this technology and the threat it is designed to meet ignores the very real danger of terrorism and our greatest danger—terrorists with weapons of mass destruction.John Edwards and I will be committed to developing a missile defense system that works, is fully tested, and geared to the threats we face. But I will refocus our efforts on preventing the spread of nuclear, biological, and chemical weapons and dramatically accelerating the security of nuclear weapons and material in Russia and around the world. We will not sit by, falsely comforted by an untested and unproven defense system, while these threats continue to fester.2Section:ChooseTop of page1BushKerry2 <<BushKerry3BushKerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerry Climate change: Virtually all reputable research in recent years has reinforced the scientific conclusion that global warming is a real and growing crisis caused, at least in part, by the burning of fossil fuels. Do you accept that scientific consensus? Under what circumstances would you regulate carbon dioxide and other greenhouse gas emissions? BushSection:ChooseTop of page1BushKerry2Bush <<Kerry3BushKerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryGlobal climate change is a serious long-term issue. In 2001, I asked the National Academy of Sciences (NAS) to provide the most up-to-date information about the science of climate change. The academy found that considerable uncertainty remains about the effect of natural fluctuations on climate and the future effects climate change will have on our environment.My administration is now well along in implementing a comprehensive climate change strategy to advance the science, expand the use of transformational energy and carbon sequestration technologies, and mitigate the growth of greenhouse gas emissions in the United States and in partnership with other nations. I created the new US Climate Change Science Program (CCSP) to refocus the federal government’s climate research programs, for which my 2005 budget seeks nearly $2 billion to fund research across the federal government. The NAS endorsed the CCSP strategic plan, noting that it “articulates a guiding vision, is appropriately ambitious, and is broad in scope.”I also committed the nation to a goal of reducing American greenhouse gas intensity by 18% over the next 10 years, which would prevent more than 500 million tons of carbon emissions through 2012. To help achieve this goal, I created the Climate Vision program in 2003 to reduce the growth of greenhouse gas emissions by energy-intensive industrial sectors. Participants in the Climate Vision program account for between 40 and 45% of US greenhouse gas emissions. I have strongly supported over $4 billion in tax incentives for renewable and energy-efficient technologies, including wind and solar energy and hybrid and fuel-cell vehicles. Also, in April 2003, my administration raised the fuel economy standards for light trucks and SUVs [sport utility vehicles] for the first time since 1996, saving 3.6 billion gallons of gasoline. And in my 2003 State of the Union [address], I announced a $1.7 billion hydrogen fuel initiative to accelerate research that could lead to hydrogen-powered, no-emission vehicles within a generation.Additionally, my administration is participating in robust international partnerships to promote clean, renewable, commercially available fusion energy and to construct the $1 billion FutureGen project, which will test the latest technologies to generate electricity, produce hydrogen, and sequester greenhouse gas emissions from coal. KerrySection:ChooseTop of page1BushKerry2BushKerry <<3BushKerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryI recognize the risk of climate change, and I have outlined a balanced set of programs that will have impact both in the near term and over the long term. My plan will also provide balanced support for technology that can increase the efficiency and cut greenhouse emissions in transportation systems, buildings, and industry that are attractive to consumers and US producers. Our programs will encourage the use of renewable fuels such as ethanol and renewable electric generation that produce little or no net greenhouse gases. I will expand the production tax credit for wind and biomass energy to cover the full array of renewable energy sources and increase Department of Energy (DOE) research into renewable energy sources and their applications. And I will propose an aggressive program of research, standards, and incentives to accelerate electric generation from renewable energy. Clean coal technology can play a critical role, given technology to cut carbon dioxide emissions.My plan would encourage energy efficiency with programs such as updated fuel efficiency standards, new tax incentives for automakers to build the new, more efficient automobiles of the future, and tax incentives for families to purchase more energy-efficient cars, trucks, and SUVs.3Section:ChooseTop of page1BushKerry2BushKerry3 <<BushKerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerry Science investment: There is concern in the science and economic communities that the US is losing its world leadership in the sciences, which they say bodes ill for future economic growth and global competitive-ness. To address that concern, should the US increase funding for basic science, and should the administration fully fund the 2001 bill, signed by the president, to double NSF’s budget? How would you reinvigorate science education for US-born students? What is the role of foreign scientists and students in the US scientific enterprise? BushSection:ChooseTop of page1BushKerry2BushKerry3Bush <<Kerry4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryIncluding my FY 2005 budget request, total federal R&D investment during the first term will have increased 44% to a record $132 billion in 2005. My FY 2005 budget request commits 13.5% of total discretionary outlays to R&D, the highest level in 37 years. In the context of the overall economy, federal R&D spending in the FY 2005 budget is the greatest share of GDP [gross domestic product] in over 10 years. Funding for basic research, the fuel for future technology development, is at an all-time high of $26.8 billion in FY 2005, a 26% increase over FY 2001. Funding for NSF during the four years of my administration has increased 30% over FY 2001 to $5.7 billion in FY 2005. NSF’s broad support for basic research, particularly at US academic institutions, provides not only a central source for discovery in many fields but also encourages and supports development of the next generation of scientists and engineers. Moreover, in fulfilling its mission, NSF has used its funding efficiently and effectively.As for the American scientific enterprise, it is important in this information and technological age that our students receive a first-rate science education, just as they receive quality instruction in reading, writing, and math. The federal government has no control over local curricula, and it is not my job to tell states and local boards of education what they should teach in the classroom. Nevertheless, the No Child Left Behind Act, one of my proudest legislative achievements this term, is improving our schools and, consequently, the teaching of science. NCLB requires, for the first time, assessments in science to give us better information about how our students are performing and how to improve instruction in science. I have also proposed creating the Presidential Math and Science Scholars Fund to provide $100 million in grants to low-income students who study math or science. This will ensure that America’s graduates have the training they need to compete for the best jobs of the 21st century.I also value the contributions that foreign scientists and students make to our nation’s scientific enterprise, while recognizing the importance of safeguarding our security. We will continue to welcome international students and scientists while implementing balanced measures to end abuses of the student visa system. My administration has already achieved several notable successes in reducing delays now being experienced by some visa seekers. We have increased security while speeding up the clearance process; approximately 1000 back-logged applications have already been cleared out.KerrySection:ChooseTop of page1BushKerry2BushKerry3BushKerry <<4BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryFor three years, the Bush administration has squandered America’s leadership in the world, putting politics before science and doing nothing to create jobs while our workers fall further behind. The administration has proposed cuts for scientific research and grossly distorted and politicized science on issues from mercury pollution to stem-cell research. This approach not only limits the research that our scientists are doing today, it undermines important discoveries of tomorrow and threatens America’s critical edge in innovation. I will reverse this course by restoring America’s scientific leadership, helping find new cures, moderating healthcare costs, and developing new technologies that will create good jobs. I will boost support for the physical sciences and engineering by increasing research investments in agencies such as NSF, the National Institutes of Health, DOE, NIST, and NASA. This funding will help with the broad areas of science and technology that will provide the foundations for economic growth and prosperity in the 21st century.4Section:ChooseTop of page1BushKerry2BushKerry3BushKerry4 <<BushKerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerry Nuclear weapons: Does the US need to develop a new class of nuclear weapons to deal with the changing threats of the 21st century? Is there any circumstance in which you would support the resumption of nuclear testing? BushSection:ChooseTop of page1BushKerry2BushKerry3BushKerry4Bush <<Kerry5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryThe Nuclear Posture Review, released by my administration in January 2002, noted that the nation’s nuclear infrastructure had atrophied since the end of the cold war and that the evolving security environment requires a flexible and responsive weapons complex infrastructure. To that end, my FY 2005 budget reflects an increase over the 2004 enacted level in the weapons activities account, which encompasses the stockpile stewardship programs. There is no current need for testing due to the sophistication of computer modeling and other new technologies, but we must maintain the capability to test in case such testing becomes necessary in the future to ensure the safety and reliability of our defensive arsenal. We have not identified any need for developing new nuclear weapons. KerrySection:ChooseTop of page1BushKerry2BushKerry3BushKerry4BushKerry <<5BushKerry6BushKerry7BushKerry8BushKerry9BushKerryNo, and a Kerry–Edwards administration will stop this administration’s program to develop a new class of nuclear weapons. This is a weapon we don’t need, and it undermines our ability to persuade other nations to forego development of these weapons.5Section:ChooseTop of page1BushKerry2BushKerry3BushKerry4BushKerry5 Nuclear There is serious concern many that could or a nuclear in a US Do you the US is doing to and control of nuclear weapons and material both in the US and BushSection:ChooseTop of administration in has more to and control nuclear weapons and material than US weapons and are and both the Department of Defense and are to make more My administration has increased funding to weapons and material in the Union and has by years the schedule the administration for security in We are with Russia to end the production of and to weapons for of weapons. the my administration the to or and material We have already weapons material from several our in its for nuclear weapons. To against we the international in a global effort to account and of sources that could be used in such We activities in over 40 on this as well as with international the Energy the the and the of Defense we have dramatically our ability to that could be a threat to us and to our friends and my administration the billion initiative to support and nuclear safety in the This of the international is to a more of nation’s highest must be preventing from to nuclear weapons and the material to make We must in a global partnership with other nations to prevent the spread of these weapons. the Bush administration’s have in the have the we need to advance our security. September they have not nearly to and on the while the nuclear from and North Korea have Our security requires an immediate change of I have proposed a comprehensive strategy to of weapons and including an of programs to all nuclear weapons and within the and at research in the within four production of new material for nuclear weapons by a global on production of new of nuclear weapons and by development of the new generation of nuclear accelerating in US and nuclear and reducing of in nuclear weapons programs in hostile including by with North Korea to ensure the and of its nuclear weapons program and a global effort to prevent from the necessary to build nuclear weapons. international efforts to by and and as well as improving the security a presidential to prevent nuclear terrorism who will focus on a effort to all nuclear weapons and around the world and prevent a nuclear terrorist of Energy than of and have not in a comprehensive US energy policy. years into the future, what do you the US energy should How would you the US in that BushSection:ChooseTop of and energy is critical to America’s and homeland security. We will be more and more we are on foreign sources of energy. The of a comprehensive and balanced national energy policy has been one of my During my first in I proposed a national energy policy that would our energy production and systems, reduce our on foreign promote efficiency and increase domestic production from all of energy including renewable energy and continue to our economy and create new jobs. We will continue to with on the energy to the administration has nearly all of the more than in the comprehensive national energy policy that not as increasing reliability R&D to help prevent and the to its of million to provide energy security in case of of have proposed an program of research, and standards that would increase the efficiency of energy use and use of new energy sources that can ensure a and while reducing the risk of climate change. The program would be supported in by a billion energy security and from federal and gas the in by I have to around the and a of that can meet US needs both in the term and for in the Given the long time required to over energy investments such as of and trucks, industrial and we must a broad set of new technologies as as possible we have any of US energy use in the near term, many of the most control systems, and other technologies to improve the energy of buildings, and industrial that the US to reduce its on from the and I will set for fuels such as I will support research and incentives that will dramatically increase use of from wind and other renewable And I will encourage development of technology and nuclear generation with high standards for stewardship and of Nuclear recent by that nuclear is the best energy source to meet the US while protecting the renewable energy can be deployed on a Do you increasing the use of nuclear If what would you do with the BushSection:ChooseTop of support the further development of nuclear technologies as a clean, and to meet this nation’s future energy Nuclear for of our This which no pollution or greenhouse gas can play an expanding role in our energy future while the we with energy national energy policy several to encourage increased use of nuclear and to the that through the Nuclear my administration is with industry to the for an of a new US nuclear within the next years. through the the United States is with around the to develop a next generation of more and more nuclear that can also produce hydrogen and my administration has made a to the nuclear and the of a long-term at We are ahead with the of a to the Nuclear at the end of this administration is also committed to and in new technologies that will change the we generate I committed the United States to the international fusion energy as in is a important to test the of nuclear fusion as a source of and the of a nearly source of energy the that long-term of Nuclear can play an role in energy while reducing the risk of climate key such as nuclear nuclear and security must be John Edwards and I will ensure safety and science We George Bush’s plan to over the of a Kerry–Edwards administration will on science. John Edwards and I do not support as a nuclear and will that nuclear and transportation only on the of science and that to and the John Edwards and I will George Bush and to from a for an NAS study to is the as to long-term and or some other technology. an international to scientific for nuclear and nuclear from terrorist John Edwards and I will improve and security at nuclear In we will nuclear to to improve including measures to reduce to the an of National National Nuclear the national weapons continue to be with security spending and What would you to improve at the Does the current plan of the to the risk of the in the of the war on BushSection:ChooseTop of national are doing to deal with the threats of the 21st are a in our efforts to improve homeland are the source of technological and are helping the war on With their at the highest level in years, National National and National are also on the edge of defense research, protecting the nation’s infrastructure from terrorist attacks, and developing a that the of a nuclear This is we billion on weapons research and production in FY 2004 and I for billion for We must and security My administration has made effort to improve the the weapons do and one of efforts is that in all areas of central to the war on we can use our more and focus on his or of national play a critical role in our nuclear weapons stockpile and that our nation’s nuclear weapons are and The national also have an important role in preventing the spread of weapons of mass and in science for our nation’s have a of our nation’s but this record has been by and security at the has been John Edwards and I are committed to and and restoring the at these critical national of is being to the long-term of to the and Many scientists the will money from science How do you the importance of science exploration What is the funding between the BushSection:ChooseTop of I announced my for the future of America’s space exploration this will the of both and science will as to the and other vehicles continue to their and of to we have systems on and around a system and one on its to the for cannot be by the most or the most We need to and and for And only are of to the by space we our on the we are developing a new exploration to our This will be by and its first no than will to the as as and no than and use it as a for the We will with to the and for future will with the goal of and there for of Edwards and I will continue America’s long tradition of leadership in and space exploration as of a program to broad for this will not to programs such as the Bush administration’s Program that from in the with no or will in new programs to set by scientific in and other Our administration will on the of the scientific to the most for research and the most for these the of or are most to the 2004 American of

Two possible physical concepts of cosmic nuclear power plants are considered. One of them is a fast nuclear reactor cooled by Na-K-Cs alloy. The fuel, coolant, and reactor reflector contain long-lived radioactive waste from nuclear power (including minor actinides and fission products. The values of the maximum temperature of the core components in anticipated transients without scram (ATWS) are given. The second concept is a hybrid of a “nuclear battery” and a nuclear reactor. It is proposed to use super-heavy elements as a fuel (flerovium-298), lead and gallium are most preferable as a coolant. The estimated values of the critical parameters of such a reactor are given. The reactor is characterized by a good neutron balance. Both concepts are designed for use on space stations and (or) as stationary installations on the terrestrial planets (with a solid surface). The implementation of the first concept is possible in the framework of existing technologies. The second concept can only be implemented in the far future. Its implementation will be possible when producing a significant amount of long-lived super-heavy elements and will require the development of new technologies.

Space nuclear reactor power is the application of self-sustaining nuclear fission energy in space, which can fundamentally solve the bottleneck problem of high power demand of spacecraft in the future. It is also the premise of large-scale development and utilization of space resource. New technology of nuclear reactor power and its development roadmaps are reviewed in this paper. Based on the future development trend, mission requirment, and main technical route, we suggest that the space nuclear reactor power could be developed in stages according to grades of 10, 100, 1000 kWe. Issues of key technologies and nuclear safety are also analyzed. The content of this work may provide a reference for the future development of space nuclear reactor power.

Core power control of a space nuclear reactor based on a nonlinear model and fuzzy-PID controller

Chapter Seventeen - Space nuclear power: Radioisotopes, technologies, and the future

Optimization of thermodynamic performance and mass evaluation for MW-class space nuclear reactor coupled with noble gas binary mixtures Brayton cycle

The Automatic Control System (ACS) of the space nuclear reactor power system TOPAZ II that generates electricity from nuclear heat using in‐core thermionic converters is considered. Sliding Mode Control Technique was applied to the reactor system controller design in order to provide the robust high accuracy following of a neutron (thermal) power reference profile in a start up regime and a payload electric power (current) reference profile following in an operation regime. Extensive simulations of the TOPAZ II reactor system with the designed sliding mode controllers showed improved accuracy and robustness of the reactor system performances in a start up regime and in an electric power supply regime as well.

The automatic control system (ACS) of the space nuclear reactor power system TOPAZ II that generates electricity from nuclear heat using in-core thermionic converters is considered. The sliding mode control technique was applied to the reactor system controller design in order to provide the robust high accuracy following of a neutron (thermal) power reference profile in a start up regime and a payload electric power (current) reference profile following in an operation regime. Extensive simulations of the TOPAZ II reactor system with the designed sliding mode controllers showed improved accuracy and robustness of the reactor system performances in a start up regime and in an electric power supply regime as well.

A detailed model of the electromagnetic pump of the TOPAZ-II space nuclear reactor power system is developed and compared with experimental data. The magnetic field strength in the pump depends not only on the current supplied by the pump thermionic fuel elements in the reactor core but also on the temperature of the coolant, the magnetic coil, and the pump structure. All electric and thermal properties of the coolant, wall material of the pump ducts, and electric leads are taken to be temperature dependent. The model predictions are in good agreement with experimental data.