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Title: Toward A Secure and Sustainable Energy Future.


Abstract not provided.

Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: Proposed for presentation at the Commercialization of Micro, Nano, and Emerging Technologies held August 29, 2016 in Houston, TX.
Country of Publication:
United States

Citation Formats

Torres, Juan J. Toward A Secure and Sustainable Energy Future.. United States: N. p., 2016. Web.
Torres, Juan J. Toward A Secure and Sustainable Energy Future.. United States.
Torres, Juan J. 2016. "Toward A Secure and Sustainable Energy Future.". United States. doi:.
title = {Toward A Secure and Sustainable Energy Future.},
author = {Torres, Juan J.},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 8

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  • Abstract not provided.
  • Abstract not provided.
  • Over the past five years, the Department of Energy's Office of Basic Energy Sciences has engaged thousands of scientists around the world to study the current status, limiting factors and specific fundamental scientific bottlenecks blocking the widespread implementation of alternate energy technologies. The reports from the foundational BESAC workshop, the ten 'Basic Research Needs' workshops and the panel on Grand Challenge science detail the necessary research steps ( This report responds to a charge from the Director of the Office of Science to the Basic Energy Sciences Advisory Committee to conduct a study with two primary goals: (1) to assimilatemore » the scientific research directions that emerged from these workshop reports into a comprehensive set of science themes, and (2) to identify the new implementation strategies and tools required to accomplish the science. From these efforts it becomes clear that the magnitude of the challenge is so immense that existing approaches - even with improvements from advanced engineering and improved technology based on known concepts - will not be enough to secure our energy future. Instead, meeting the challenge will require fundamental understanding and scientific breakthroughs in new materials and chemical processes to make possible new energy technologies and performance levels far beyond what is now possible.« less
  • Significant progress and improvements have been made on development of a pre-conceptual design of the Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) concept since it was last reported on at ICAPP 05. SSTAR is a small, 20 MWe (45 MWt), exportable, natural circulation, fast reactor plant concept incorporating proliferation resistance for deployment in non-fuel cycle states and developing nations, fissile self-sufficiency for efficient utilization of uranium resources, autonomous load following making it suitable for small or immature grid applications, and a high degree of passive safety. Customers of SSTAR include: (1) clients looking for energy security at smallmore » capital outlay; (2) cities in developing nations; and (3) deregulated independent power producers in developed nations. The SSTAR pre-conceptual design integrates three major features: primary coolant natural circulation heat transport; lead (Pb) coolant; and transuranic nitride fuel in a pool vessel configuration. The Pb coolant flows upward through the core which is an open-lattice of large-diameter (2.5 centimeter) fuel pins containing transuranic nitride pellets clad bonded with liquid Pb to silicon-enhanced ferritic/martensitic (F/M) stainless steel arranged on a triangular pitch with spacing maintained by grid spacers; the core does not incorporate removable fuel assemblies as one means of restricting access to the fuel. The whole core is a single removable assembly with a long lifetime (30 years) at which time refueling equipment is brought onsite. Conversion of the core thermal energy to electricity is accomplished using a supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converter providing higher plant efficiencies and lower balance of plant costs than the traditional Rankine steam cycle operating at the same reactor core outlet temperature. A control strategy has been developed for automatic control of the S-CO{sub 2} Brayton cycle in principle enabling autonomous load following over the full power range between nominal and essentially zero power whereby the reactor core power adjusts itself to the heat removal from the reactor system to the power converter through the large reactivity feedback of the fast spectrum core without the need for motion of control rods, while the automatic control of the power converter matches the heat removal from the reactor to the grid load. A safety design approach has been formulated for SSTAR based upon defense-in-depth providing multiple levels of protection against the release of radioactive materials. The inherent safety features of the lead coolant (T{sub boil} = 1740 C, lack of chemical reaction of Pb with the CO{sub 2} working fluid, low absorption of neutrons by Pb, and the heavy Pb), nitride fuel (high thermal conductivity, transuranic nitride decomposition temperature {approx} 1300 C, compatibility with cladding, low volumetric swelling and fission gas release), fast neutron spectrum core, pool vessel configuration, natural circulation, and containment enable the requirements for each level of protection to be readily met or exceeded. The interest in higher plant efficiencies has heretofore driven interest in operation of SSTAR at higher Pb temperatures to take advantage of the increase in plant efficiency with temperature of the S-CO{sub 2} Brayton cycle. A peak cladding temperature of 650 C has been used as a goal; at this temperature, a reactor core outlet temperature of 564 C is achieved resulting in a Brayton cycle efficiency of 44.2 % and a net plant efficiency of 43.8 %. It has always been recognized that this would require the development of cladding and structural materials for long-term service in Pb coolant up to 650 C peak cladding temperature with corrosion protection provided by active maintenance and control of the dissolved oxygen potential in the coolant giving rise to the formation of protective oxide layers on the steel cladding and structures. SSTAR development has been supported by the testing in the DELTA loop at Los Alamos National Laboratory of alloy specimens with special treatments or coatings which might enhance corrosion resistance at the temperatures at which SSTAR operates. The focus of LFR development in the U.S. is now shifting towards the development of a near-term deployable LFR test demonstrator and a near-term deployable small exportable LFR. Both reactors would operate at lower temperatures enabling the use of existing materials such as T91 or HT9 F/M stainless steel that is already incorporated into the ASME codes and have been shown to have corrosion resistance to lead-bismuth eutectic with active oxygen control at temperatures below about 550 C in experiments carried out in the DELTA loop and elsewhere.« less
  • The potential for improving energy efficiency is enormous, but exploitation of this resource has slowed in recent years. This is regrettable for several reasons. First, not incorporating higher efficiency now often means passing up opportunities that will be more expensive or even impossible to implement in the future. This is especially true for long-lived capital, such as new buildings. Second, reduced research and development into new efficiency options will make it more difficult to accelerate the pace of efficiency improvements in the future. Finally, the flow of more efficient technologies to the non-OECD countries will be hindered by the slowdownmore » in efficiency improvement in the OECD countries. Well-designed policies can help recapture the momentum that has been lost. Some key steps for stimulating more careful use of energy are: rationalize energy pricing and gradually internalize environmental externalities; improve present energy-using capital; implement energy-efficiency standards or agreements for new products and buildings; encourage higher energy efficiency in new products and buildings; promote international cooperation for R&D technology transfer; adjust policies that encourage energy-intensive activities; and promote population restraint worldwide. 25 refs.« less