• 제목/요약/키워드: Massachusetts Institute of Technology

검색결과 184건 처리시간 0.019초

Spin transport studies in organic semiconductors and spin filter tunneling

  • Moodera, Jagadeesh;Santos, Tiffany S.;Shim, Jenny;Lee, Joo-Sang;Park, Young-Ju;Nagahama, Taro;Miao, Guo-Xing;Venkataraman, Karthik;Choi, Deung-Jang
    • 한국자기학회:학술대회 개요집
    • /
    • 한국자기학회 2007년도 동계학술연구발표회 및 스핀트로닉스와 나노물리에관한 국제심포지움
    • /
    • pp.17-17
    • /
    • 2007
  • PDF

A central facility concept for nuclear microreactor maintenance and fuel cycle management

  • Faris Fakhry;Jacopo Buongiorno;Steve Rhyne;Benjamin Cross;Paul Roege;Bruce Landrey
    • Nuclear Engineering and Technology
    • /
    • 제56권3호
    • /
    • pp.855-865
    • /
    • 2024
  • Commercial deployment of nuclear microreactors presents an opportunity for the industry to rethink its approach to manufacturing, siting, operation and maintenance, and fuel cycle management as certain principles used in grid-scale nuclear projects are not applicable to a decentralized microreactor economy. The success of this nascent industry is dependent on its ability to reduce infrastructure, logistical, regulatory and lifecycle costs. A utility-like 'Central Facility' that consolidates the services required and responsibilities borne by vendors into one or a few centralized locations will be necessary to support the deployment of a fleet of microreactors. This paper discusses the requirements for a Central Facility, its implications on the cost structures of owners and suppliers of microreactors, and the impact of the facility for the broader microreactor industry. In addition, this paper discusses the pre-requisites for eligibility as well as the opportunities for a Central Facility host site. While there are many suitable locations for such a capability across the U.S., this paper considers a facility co-located with the Vogtle Nuclear Power Plant and Savannah River Sites to illustrate how a Central Facility can leverage the existing infrastructure and stimulate a local ecosystem.

Development of Cr cold spray-coated fuel cladding with enhanced accident tolerance

  • Sevecek, Martin;Gurgen, Anil;Seshadri, Arunkumar;Che, Yifeng;Wagih, Malik;Phillips, Bren;Champagne, Victor;Shirvan, Koroush
    • Nuclear Engineering and Technology
    • /
    • 제50권2호
    • /
    • pp.229-236
    • /
    • 2018
  • Accident-tolerant fuels (ATFs) are currently of high interest to researchers in the nuclear industry and in governmental and international organizations. One widely studied accident-tolerant fuel concept is multilayer cladding (also known as coated cladding). This concept is based on a traditional Zr-based alloy (Zircaloy-4, M5, E110, ZIRLO etc.) serving as a substrate. Different protective materials are applied to the substrate surface by various techniques, thus enhancing the accident tolerance of the fuel. This study focuses on the results of testing of Zircaloy-4 coated with pure chromium metal using the cold spray (CS) technique. In comparison with other deposition methods, e.g., Physical vapor deposition (PVD), laser coating, or Chemical vapor deposition techniques (CVD), the CS technique is more cost efficient due to lower energy consumption and high deposition rates, making it more suitable for industry-scale production. The Cr-coated samples were tested at different conditions ($500^{\circ}C$ steam, $1200^{\circ}C$ steam, and Pressurized water reactor (PWR) pressurization test) and were precharacterized and postcharacterized by various techniques, such as scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX), or nanoindentation; results are discussed. Results of the steady-state fuel performance simulations using the Bison code predicted the concept's feasibility. It is concluded that CS Cr coating has high potential benefits but requires further optimization and out-of-pile and in-pile testing.

Principle-based Parsing for Chinese

  • Yang, Charles D.;Berwick, Robert C.
    • 한국언어정보학회:학술대회논문집
    • /
    • 한국언어정보학회 1996년도 Language, Information and Computation = Selected Papers from the 11th Pacific Asia Conference on Language, Information and Computation, Seoul
    • /
    • pp.363-372
    • /
    • 1996
  • PDF

EXPERIMENTAL STUDY OF CRITICAL HEAT FLUX WITH ALUMINA-WATER NANOFLUIDS IN DOWNWARD-FACING CHANNELS FOR IN-VESSEL RETENTION APPLICATIONS

  • Dewitt, G.;Mckrell, T.;Buongiorno, J.;Hu, L.W.;Park, R.J.
    • Nuclear Engineering and Technology
    • /
    • 제45권3호
    • /
    • pp.335-346
    • /
    • 2013
  • The Critical Heat Flux (CHF) of water with dispersed alumina nanoparticles was measured for the geometry and flow conditions relevant to the In-Vessel Retention (IVR) situation which can occur during core melting sequences in certain advanced Light Water Reactors (LWRs). CHF measurements were conducted in a flow boiling loop featuring a test section designed to be thermal-hydraulically similar to the vessel/insulation gap in the Westinghouse AP1000 plant. The effects of orientation angle, pressure, mass flux, fluid type, boiling time, surface material, and surface state were investigated. Results for water-based nanofluids with alumina nanoparticles (0.001% by volume) on stainless steel surface indicate an average 70% CHF enhancement with a range of 17% to 108% depending on the specific flow conditions expected for IVR. Experiments also indicate that only about thirty minutes of boiling time (which drives nanoparticle deposition) are needed to obtain substantial CHF enhancement with nanofluids.

Technology Selection for Offshore Underwater Small Modular Reactors

  • Shirvan, Koroush;Ballinger, Ronald;Buongiorno, Jacopo;Forsberg, Charles;Kazimi, Mujid;Todreas, Neil
    • Nuclear Engineering and Technology
    • /
    • 제48권6호
    • /
    • pp.1303-1314
    • /
    • 2016
  • This work examines the most viable nuclear technology options for future underwater designs that would meet high safety standards as well as good economic potential, for construction in the 2030-2040 timeframe. The top five concepts selected from a survey of 13 nuclear technologies were compared to a small modular pressurized water reactor (PWR) designed with a conventional layout. In order of smallest to largest primary system size where the reactor and all safety systems are contained, the top five designs were: (1) a lead-bismuth fast reactor based on the Russian SVBR-100; (2) a novel organic cooled reactor; (3) an innovative superheated water reactor; (4) a boiling water reactor based on Toshiba's LSBWR; and (5) an integral PWR featuring compact steam generators. A similar study on potential attractive power cycles was also performed. A condensing and recompression supercritical $CO_2$ cycle and a compact steam Rankine cycle were designed. It was found that the hull size required by the reactor, safety systems and power cycle can be significantly reduced (50-80%) with the top five designs compared to the conventional PWR. Based on the qualitative economic consideration, the organic cooled reactor and boiling water reactor designs are expected to be the most cost effective options.