Review of DOE's Nuclear Energy Research and Development Program (2008) / Chapter Skim
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Pages 58-65
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From page 58... ...
These reactors had coolant, at 4 MPa, traveling downward in the core and exiting at 645°C, coupled to a steam cycle power conversion system, through a steam generator. The steam, at 17 MPa, entered the turbines at 540°C, which provided over 40 percent thermal conversion efficiency.
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From page 59... ...
The plant design was initially sized at 450 MWth with a 750ºC coolant outlet temperature and a helical steam generator providing steam to a Rankine cycle. Recently, the thermal output has been reduced to 250 MWth to facilitate early deployment.
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From page 60... ...
In addition, process heat plant development is ongoing to evaluate the best applications for this HTR technology and to assess the economic competitiveness against the competing fuel, natural gas. Finally, pre-application review for design certification of the basic technology has already started in the United States, and the USNRC activity is timed to be consistent with the development of information, including the licensing documentation, on the South African Demonstration Power Plant.
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From page 61... ...
In the future, even larger quantities of natural gas may be required to produce liquid fuels from unconventional sources that are abundant in North America, including tar sands, shale oils, coal and biomass. Liquid fuels can be expected to play a continuing large role in the transportation sector, supplemented in the longer term by hydrogen fuel cells or chargeable batteries for ground transportation.
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From page 62... ...
HTRs can also provide high-temperature process heat between 600°C and 950°C and can directly displace natural gas in these applications, as discussed earlier. Nuclear Hydrogen Hydrogen is being used to upgrade heavier crude oils.
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From page 63... ...
In addition, the goals of better economy and process heat applications call for operating the NGNP and future HTRs at even higher temperatures than those attained in past reactors, which implies materials development and other technology needs. Such needs have been reviewed in the past by an Independent Technology Review Group (ITRG, 2004)
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From page 64... ...
be chemically compatible with the surrounding structural materials, (2) have superior fluid-mechanical and heattransfer properties for an economical design of the process heat exchangers and the heat transport loop, and (3)
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From page 65... ...
The results of these studies will provide insights into the reactor design conditions, including provision of direct versus indirect process heat cycles and relying on steam power cycles instead of helium gas turbines at the outset. Safety and Licensing There needs to be a discussion with the USNRC on the key aspects of safety and licensing that should be addressed if the NGNP is deployed in the 2017 to 2021 timeframe.
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