Accelerator parameters for subcritical reactors have usually been based on using solid nuclear fuel much like that used in all operating critical reactors as well as the thorium burning accelerator-driven energy amplifier proposed by Rubbia et al. An attractive alternative reactor design that used molten salt fuel was experimentally studied at ORNL in the 1960s, where a critical molten salt reactor was successfully operated using enriched U235 or U233 tetrafluoride fuels. These experiments give confidence that an accelerator-driven subcritical molten salt reactor will work better than conventional reactors, having better efficiency due to their higher operating temperature, having the inherent safety of subcritical operation, and having constant purging of volatile radioactive elements to eliminate their accumulation and potential accidental release in dangerous amounts. Moreover, the requirements to drive a molten salt reactor can be considerably relaxed compared to a solid fuel reactor, especially regarding accelerator reliability and spallation neutron targetry, to the point that much of the required technology exists today. It is proposed that Project-X be developed into a prototype commercial machine to produce energy for the world by, for example, burning thorium in India and nuclear waste from conventional reactors in the USA.
This book describes the basic knowledge in nuclear, neutron, and reactor physics necessary for understanding the principle and implementation of accelerator driven subcritical nuclear reactors (ADSRs), also known as hybrid reactors. Since hybrid reactors may contribute to future nuclear energy production, the book begins with a discussion of
The application of thermal-spectrum molten-salt reactors and accelerator-driven subcritical systems to the destruction of weapons-return plutonium is considered from the perspective of deriving the maximum societal benefit. The enhancement of electric power production from burning the fertile fuel 232Th with the plutonium is evaluated. Also the enhancement of destruction of the accumulated waste from commercial nuclear reactors is considered using the neutron-rich weapons plutonium. Most cases examined include the concurrent transmutation of the long-lived actinide and fission product waste (99Tc, 129I, 135Cs, 126Sn and 79Se).
This book offers a comprehensive overview of the reprocessing of spent nuclear fuels, and discusses the applications of radiation, particularly spallation neutrons and gamma rays. The unspent nuclear fuel of a reactor amounts to roughly 95 per cent of the loaded fuel. It contains both fertile and fissile fuels, minor and higher actinides and radioactive fission products. In 2015, out of approximately 4 million metric tons of spent fuel, only 90,000 metric tons was reprocessed worldwide; the rest was either sent to repositories, kept for cooling down, or put on a waiting list for future reprocessing. With regard to the direct reutilization of spent nuclear fuel, the new technique of ‘Energy Amplifiers’ has attracted considerable attention among the nuclear energy community. Presenting extensive information on this technique, the book is divided into eight major sections: (i) spent nuclear fuel and alternative transmutation methods, (ii) general concept of accelerator-driven subcritical systems (ADSS), (iii) spallation neutron sources and the possibility of incineration, (iv) requirements for nuclear data, (v) transmutation of spent nuclear fuel and extension of the fuel cycle, (vi) spallation neutron production facilities, (vii) major experimental facilities for ADSS, and (viii) software tools for the design and modelling of ADSS. The book is ideally suited as a textbook for graduate students as well as a reference guide for researchers and practitioners.
Molten Salt Reactors and Thorium Energy, Second Edition is a fully updated comprehensive reference on the latest advances in MSR research and technology. Building on the successful first edition, Tom Dolan and the team of experts have fully updated the content to reflect the impressive advances from the last 5 years, ensuring this book continues to be the go-to reference on the topic. This new edition covers progress made in MSR design, details innovative experiments, and includes molten salt data, corrosion studies and deployment plans. The successful case studies section of the first edition have been removed, expanded, and fully updated, and are now published in a companion title called Global Case Studies on Molten Salt Reactors. Readers will gain a deep understanding of the advantages and challenges of MSR development and thorium fuel use, as well as step-by-step guidance on the latest in MSR reactor design. Each chapter provides a clear introduction, covers technical issues and includes examples and conclusions, while promoting the sustainability benefits throughout. - A fully updated comprehensive handbook on Molten Salt Reactors and Thorium Energy, written by a team of global experts - Covers MSR applications, technical issues, reactor types and reactor designs - Includes 3 brand new chapters which reflect the latest advances in research and technology since the first edition published - Presents case studies on molten salt reactors which aid in the transition to net zero by providing abundant clean, safe energy to complement wind and solar powe
High power proton accelerators allow providing, by spallation reaction, the neutron fluxes necessary in thesynthesis of fissile material, starting from Uranium 238 or Thorium 232. This is the basis of the concept ofsub-critical operation of a reactor, for energy production or nuclear waste transmutation, with the objective ofachieving cleaner, safer and more efficient process than today's technologies allow.Designing, building and operating a proton accelerator in the 500-1000 MeV energy range, CW regime,MW power class still remains a challenge nowadays. There is a limited number of installations at presentachieving beam characteristics in that class, e.g., PSI in Villigen, 590 MeV CW beam from a cyclotron, SNS inOakland, 1 GeV pulsed beam from a linear accelerator, in addition to projects as the ESS in Europe, a 5 MWbeam from a linear accelerator.Furthermore, coupling an accelerator to a sub-critical nuclear reactor is a challenging proposition: some ofthe key issues/requirements are the design of a spallation target to withstand high power densities as well asensure the safety of the installation.These two domains are the grounds of the PhD work: the focus is on the high power ring methods inthe frame of the KURRI FFAG collaboration in Japan: upgrade of the installation towards high intensityis crucial to demonstrate the high beam power capability of FFAG. Thus, modeling of the beam dynamicsand benchmarking of different codes was undertaken to validate the simulation results. Experimental resultsrevealed some major losses that need to be understood and eventually overcome.By developing analytical models that account for the field defects, one identified major sources of imperfectionin the design of scaling FFAG that explain the important tune variations resulting in the crossing of severalbetatron resonances. A new formula is derived to compute the tunes and properties established that characterizethe effect of the field imperfections on the transverse beam dynamics. The results obtained allow to developa correction scheme to minimize the tune variations of the FFAG. This is the cornerstone of a new fixed tunenon-scaling FFAG that represents a potential candidate for high power applications.As part of the developments towards high power at the KURRI FFAG, beam dynamics studies have toaccount for space charge effects. In that framework, models have been installed in the tracking code ZGOUBIto account for the self-interaction of the particles in the accelerator. Application to the FFAG studies is shown.Finally, one focused on the ADSR concept as a candidate to solve the problem of nuclear waste. In orderto establish the accelerator requirements, one compared the performance of ADSR with other conventionalcritical reactors by means of the levelized cost of energy. A general comparison between the different acceleratortechnologies that can satisfy these requirements is finally presented.In summary, the main drawback of the ADSR technology is the high Levelized Cost Of Energy comparedto other advanced reactor concepts that do not employ an accelerator. Nowadays, this is a show-stopper forany industrial application aiming at producing energy (without dealing with the waste problem). Besides, thereactor is not intrinsically safer than critical reactor concepts, given the complexity of managing the targetinterface between the accelerator and the reactor core.
This volume captures the contents of the talks given at the Workshop on Applications of High Intensity Proton Accelerators held at Fermilab Oct 19-21, 2009. This workshop brought together experts from a variety of disciplines to explore new and profound ways proton accelerators can be used in the future. The workshop explored uses of such a proton source for producing intense muon, kaon and neutrino beams as well as using the intense protons for new forms of nuclear reactors that go by the name Accelerator Driven Sub-critical systems that promise to increase our available nuclear fuel supply by orders of magnitude while at the same time solving the nuclear waste problem. Intense proton beams can also be used to produce short-lived nuclear isotopes that are important in the medical industry.
The history of mankind is a story of ascent to unprecedented levels of comfort, productivity and consumption, enabled by the increased mastery of the basic reserves and flows of energy. This miraculous trajectory is confronted by the consensus that anthropogenic emissions are harmful and must decrease, requiring de-carbonization of the energy system. The mature field of indicator-based sustainability assessment provides a rigorous systematic framework to balance the pros and cons of the various existing energy technologies using lifecycle assessments and weighting criteria covering the environment, economy, and society, as the three pillars of sustainability. In such a framework, nuclear power is ranked favorably, but since emphasis is often placed on radioactive wastes and risk aversion, renewables are usually ranked top. However, quantifying the severity of the consequences of nuclear accidents on a rough integral cost basis and balancing severity with low core-damage accident probabilities indicates that the average external cost of such accidents is similar to that of modern renewables, and far less than carbon-based energy. This book formulates the overall goal and associated unprecedented demanding criteria of taming nuclear risks by excluding mechanisms that lead to serious accidents and avoiding extremely long stewardship times as far as possible, by design. It reviews the key design features of nuclear power generation, paving the way for the exploration of radically new combinations of technologies to come up with “revolutionary” or even “exotic” system designs. The book also provides scores for the selected designs and discusses the high potential for far-reaching improvements, with small modular lines of the best versions as being most attractive. Given the ambition and challenges, the authors call for an urgent increase in funding of at least two orders of magnitude for a broad international civilian “super-Apollo” program on nuclear energy systems. Experience indicates that such investments in fundamental technologies enable otherwise unattainable revolutionary innovations with massive beneficial spillovers to the private sector and the public for the next generations.
Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved in very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible.
Global Progress on Molten Salt Reactors: A Companion to Dolan's Molten Salt Reactors and Thorium Energy, Second Edition presents global perspectives on the latest research and technological advances. Each case study utilizes a comprehensive template that guides the reader through country specific research. Useful data which can be applied to work and research is included, along with a list of references for further research. Researchers, professional engineers and policymakers will gain a broad picture of worldwide MSR activity and a deep understanding of how theory and practical guidance is applied in a variety of settings, including budgets, approaches and constraints. - Provides a collection of case studies from 23 countries, presenting their latest research and activities on Molten Salt Reactors - Based on chapter 26 of the first edition of Dolan's Molten Salt Reactors and Thorium Energy, this companion title presents expanded and more complete coverage of global activities and research - Includes advanced technologies, reactor designs and safety and management strategies
