Gas-cooled fast-breeder reactor

Pressurized- water reactor Boiling- water reactor Liquid-metal fast-breeder reactor Gas-cooled fast-breeder reactor Molten-salt breeder reactor ... 

Surface roughening is used for the Advanced Gas-Cooled Reactors in the United Kingdom and is being considered for the gas-cooled fast-breeder reactors being studied in the United States. A doubling of the heat-transfer coefficient is obtained, for example, by tripling the friction factor (27), thus improving the merit index h f 18). 

The advanced gas-cooled reactor plants under development include the Gas-Cooled Heavy-Water Reactor, the Advanced Gas-Cooled Reactor, the High-Temperature Reactors, and the Gas-Cooled Fast-Breeder Reactor. The future trends in the development of gas-cooled reactors can be indicated by an examination of the potential performance characteristics for these reactors. 

The projections are based on a recent forecast (Case B) by the Energy Research and Development Administration (ERDA) of nuclear power growth in the United States (2) and on fuel mass-flow data developed for light water reactors fueled with uranium (LWR-U) or mixed uranium and plutonium oxide (LWR-Pu), a high temperature gas-cooled reactor (HTGR), and two liquid-metal-cooled fast breeder reactors (LMFBRs). Nuclear characteristics of the fuels and wastes were calculated using the computer code ORIGEN (3). 

PWR, pressurized-water reactor HTGR, high-temperature gas-cooled reactor LMFBR, liquid-metal-cooled fast-breeder reactor. Data are calculated for 150 days after discharge. Calculated from data in [B2]. 

Includes gas-cooled, heavy water, graphite-moderated light water, and liquid metal-cooled fast-breeder reactors. Includes reactors of all types planned or under construction. 

Other newer designs include the advanced, gas-cooled reactor (AGR), Canadian deuterium reactor (CANDUR), sodium-cooled reactor (SCR), sodium-heated reactor (SHR), and fast breeder reactor (FBR). These reactors employ either natural or enriched uranium fuels that may be modified in some way (e.g., graphite-moderated fuels). 

Three of the Generation IV designs under consideration are fast breeder reactors The fast neutrons in the core have no moderator to slow them down. When these fast neutrons collide with fuel particles, they can generate more fuel. These reactors use gas, sodium or molten lead for cooling. 

In order, the following types of nuclearfission reactors are described in this section (1) light water reactors, (a) pressurized water reactors, (b) boiling-water reactors (2) high-temperature gas-cooled reactors (3) heavy water reactors and (4) fast breeder reactors. Military reactors are not described. 

Among the reactor types studied over the past 4-5 decades, but not reaching the stage of market introduction on a commercial basis, are high-temperature gas-cooled reactors and sodium-cooled fast breeders. Current proposals are aware of the issues raised above, but still far from deal with all of them. The reactor industry has recently concluded that a new generation of safer reactors will require substantial breakthroughs (particularly in materials science) that may push commercialisation at least 25 years into the future (USDoE, 2002b). The proposed concepts are summarised in Table 5.3. 

There are a number of different nuclear reactor types. The most widely used is the light-water reactor, but graphitemoderated types, which are cooled with light-water or gas, are in operation, also heavy-water reactors. The graphitemoderated high temperature reactor is in a state of halted development, as are gas-cooled reactors and fast breeder reactors. 

The fuel elements are held in position by grid plates in the reactor core. The fuel burnup to which a reactor may be operated is expressed as megawatt-days per kilogram (MWd/kg), where MWd is the thermal output and kg is the total uranium (sum of U-235 and U-238). In light-water power reactors the core may be operated to about 35 MWd/kg (about 3.5% burnup) before fuel elements have to be replaced. In liquid metal fast breeder reactors (LMFBRs) and high temperature helium gas-cooled reactors (HTGRs), the burnups may exceed 100 MWd/kg ( 10% burnup of the heavy metal atoms). 

X 10 kJ/moljH(b)Theextremelyhightemperatureisrequired to overcome electrostatic charge repulsions between the nuclei so that they can come together to react. 21.65 (a) Boiling water reactor (b) fast breeder reactor (c) gas-cooled reactor 21.67 Hydrogen... 

The vast majority (80%) of the reactors mentioned are light-water-moderated reactors (LWR). The LWR subdivide in 60% PWR and 20% BWR. The remaining 20% of the reactors are divided among CANadian Deuterium Uranium reactor (CANDU), Reaktor Bolshoi Moshchnosti Kanalny (RBMK), large power channel reactor, gas-cooled reactor (GCR), advanced gas-cooled reactor (AGR), and fast breeder reactor (FBR). 

For sodium, steam- and gas-cooled fast reactors of 1000 and 300 MW(e the most Important integral quantities have been calculated with the differ it sets and are discussed in detail especially with respect to consequences for the fast breeder development. Here we note only that the loss in breeding ratio by 0.08, 0.09, and... 

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