Liquid metal fast-breeder reactors LMFBRs

For very long, helically coiled steam generator tubes, and for conditions typical of liquid-metal fast breeder reactors (LMFBRs), where steam is generated on the tube side, an overall heat transfer correlation for the whole boiling length (from X = 0 to X = 1.0) has been deduced experimentally (Campolunghi et al., 1977b) ... 

The plutonium fuel in a breeder reactor behaves differently than uranium. Fast neutrons are required to split plutonium. For this reason, water cannot be used in breeder reactors because it moderates the neutrons. Liquid sodium is typically used in breeder reactors, and the term liquid metal fast breeder reactor (LMFBR) is used to describe it. One of the controversies associated with the breeder reactor is that it results... 

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). 

The principal long-lived actinide elements that may enter the environment from either U or Pu fuel cycles are Pu, Am, Cm, and Np. Approximately 25% of the alpha activity estimated to be released to the atmosphere from the Liquid Metal Fast Breeder Reactor (LMFBR) fuel cycle will be contributed by 21tlAm, 21 2Cm, and 21fltCm (2)... 

The calculated elemental composition, radioactivity, and decay-heat rate for discharge fuel are shown in Table 8.7 for the uranium-fueled PWR (cf. Fig. 3.31), in Table 8.8 for the liquid-metal fast-breeder reactor (LMFBR) (cf. Fig. 3.34), and in Table 8.9 for the uranium-thorium-fueled HTGR (cf. Fig. 3.33). These quantities, expressed per unit mass of discharge fuel, are useful in the design of reprocessing operations. For the purpose of comparison, all quantities are calculated for 150 days of postirradiation cooling. 

A solvent extraction process similar to Purex using TBP was developed by the Commissariat a I Energie Atomique [Gl] for use in the French plutonium separation plant at Marcoule. Since then, the Purex process has replaced the Butex process at Windscale [W3], has been used in the Soviet Union [Sll], India [S7], and Germany [S3], and by now is the universal choice for separation of uranium and plutonium from fission products in irradiated sUghtly enriched uranium. Fuel from the liquid-metal fast-breeder reactor (LMFBR) is also reprocessed by the Purex process, with modifications to accommodate the higher concentrations of plutonium and fission products. 

For the liquid metal fast breeder reactor (LMFBR), the upper temperature limit of the steam produced is approximately 500 C (505 in the Russia BN-600 reactor, 495 °C in... 

Liquid Metal Fast Breeder Reactor (LMFBR) 0.5 0.2... 

Oxide fuels have demonstrated very satisfactory high-temperature, dimensional, and radiation stability and chemical compatibility with cladding metals and coolant in light-water reactor service. Under the much more severe conditions in a fast reactor, however, even inert UO2 begins to respond to its environment in a manner that is often detrimental to fuel performance. Uranium dioxide is almost exclusively used in light-water-moderated reactors (LWR). Mixed oxides of uranium and plutonium are used in liquid-metal fast breeder reactors (LMFBR). 

Most of the fast reactor benchmarks in the CSEWG compilation date back 10 to 20 years or more. Many of these integral measurements remain of value today, particularly those in the homogeneous cores built at Los Alamos. Data for cores with liquid-metal fast breeder reactor (LMFBR) compositions and specti a are obtained in the plate-type criticals. Some of these data were obtained by methods now considered inadequate arid have lost their usefulness. For example, measurements of fission in a counter positioned in a cavity are difficult to correct for environmental effects arid often give discrepant results. Measured capture rates are of prime importance and the foil techniqueis remain the... 

It should be noted that there are less common reactor types like the liquid metal fast breeder reactors (LMFBR) and molten salt reactors (MSR) in which fast neutrons are responsible for most of the fission reactions and the coolant can be a liquid metal (e.g., sodium or lead) or the molten salt itself. 

Liquid-metal fast-breeder reactors (LMFBRs) (Russia, SFR—BN- 1 1 0.6 0.6 5 1.6... 

This appendix provides additional materials (schematics, layouts, T—s diagrams, basic parameters, and photos) on advanced thermal (combined cycle and supercritical pressure Rankine steam turbine cycle) power plants and nuclear power plants with modern nuclear power reactors [pressurized water reactors (PWRs), boiling water reactors (BWRs), pressurized heavy water reactors (PHWRs), advanced gas-cooled reactors (AGRs), gas-cooled reactors (OCRs), light water-cooled graphitemoderated reactors (LGRs) (RBMKs and EGPs), and liquid metal fast-breeder reactors (LMFBRs) (BN-600 and BN-800)]. 

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