918 research outputs found
Method for calculating allowable creep stress in linearly increasing stress environment
Constant creep data accumulation for design stress analysis on cladding material thickness around cylindrical reactor fuel elemen
Nuclear characteristics of a fissioning uranium plasma test reactor with light-water cooling
An analytical study was performed to determine a design configuration for a cavity test reactor. Test section criteria were that an average flux of 10 to the 15th power neutrons/sq cm/sec (E less than or equal to 0.12 eV) be supplied to a 61-cm-diameter spherical cavity at 200-atm pressure. Design objectives were to minimize required driver power, to use existing fuel-element technology, and to obtain fuel-element life of 10 to 100 full-power hours. Parameter calculations were made on moderator region size and material, driver fuel arrangement, control system, and structure in order to determine a feasible configuration. Although not optimized, a configuration was selected which would meet design criteria. The driver fuel region was a cylindrical annular region, one element thick, of 33 MTR-type H2O-cooled elements (Al-U fuel plate configuration), each 101 cm long. The region between the spherical test cavity and the cylindrical driver fuel region was Be (10 vol. % H2O coolant) with a midplane dimension of 8 cm. Exterior to the driver fuel, the 25-cm-thick cylindrical and axial reflectors were also Be with 10 vol. % H2O coolant. The entire reactor was contained in a 10-cm-thick steel pressure vessel, and the 200-atm cavity pressure was equalized throughout the driver reactor. Fuel-element life was 50 hr at the required driver power of 200 MW. Reactor control would be achieved with rotating poison drums located in the cylindrical reflector region. A control range of about 18 percent delta k/k was required for reactor operation
Neutronic design for a lithium-cooled reactor for space applications
Neutronic design calculations for lithium 7 cooled nuclear reactor for space application
Neutronics analysis of an open-cycle high-impulse gas core reactor concept
A procedure was developed to calculate the critical fuel mass, including the effects of propellant pressure, for coaxial-flow gas-core reactors operating at 196,600 newtons thrust and 4400 seconds specific impulse. Data were generated for a range of cavity diameter, reflector-moderator thickness, and quantity of structural material. Also presented are such core characteristics as upper limits on cavity pressure, spectral hardening in very-high-temperature hydrogen, and reactivity coefficients
Reactor moderator, pressure vessel, and heat rejection system of an open-cycle gas core nuclear rocket concept
A preliminary design study of a conceptual 6000-megawatt open-cycle gas-core nuclear rocket engine system was made. The engine has a thrust of 196,600 newtons (44,200 lb) and a specific impulse of 4400 seconds. The nuclear fuel is uranium-235 and the propellant is hydrogen. Critical fuel mass was calculated for several reactor configurations. Major components of the reactor (reflector, pressure vessel, and waste heat rejection system) were considered conceptually and were sized
Nuclear design and experiments for a space power reactor
Design and experiments with compact fast spectrum reactor for generating electric power in spac
A seismic refraction and reflection study of continent-ocean transition beneath the north Biscay margin
Scenarios for the Development of Smart Grids in the UK: Synthesis Report
Building on extensive expert feedback and input, this Research Report describes four smart grid scenarios which consider how the UK' electricity system might develop to 2050. The scenarios outline how political decisions, as well as those made in regulation, finance, technology, consumer and social behaviour, market design or response, might affect the decisions of other actors and limit or allow the availability of future options
Scenarios for the Development of Smart Grids in the UK: Literature Review
This Working Paper reviews the existing literature on the socio-technical aspects of smart grid development. This work was undertaken as part of the Scenarios for the Development of Smart Grids in the UK project
Changing social contracts in climate-change adaptation
Risks from extreme weather events are mediated through
state, civil society and individual action
1
,
2
. We propose evolving
social contracts as a primary mechanism by which adaptation
to climate change proceeds. We use a natural experiment
of policy and social contexts of the UK and Ireland affected
by the same meteorological event and resultant flooding in
November 2009. We analyse data from policy documents and
from household surveys of 356 residents in western Ireland and
northwest England. We find significant differences between
perceptions of individual responsibility for protection across
the jurisdictions and between perceptions of future risk from
populations directly affected by flooding events. These explain
differences in stated willingness to take individual adaptive
actions when state support retrenches. We therefore show
that expectations for state protection are critical in mediating
impacts and promoting longer-term adaptation. We argue
that making social contracts explicit may smooth pathways to
effective and legitimate adaptation
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