Nuclear reactors schematic diagram

Figure 2.13 Schematic diagram of the nuclear processes involved in neutron activation analysis. Prompt gamma neutron activation analysis (PGNAA) occurs within the reactor delayed gamma NAA (DGNAA) occurs at some remote site. (After Glascock, 1994 Fig. 1. John Wiley Sons Limited. Reproduced with permission.)...

In the closed cycle, the heat is added to the fluid in a heat exchanger from an external heat source, such as a nuclear reactor, and the fluid is cooled in another heat exchanger after it leaves the turbine and before it enters the compressor. A schematic diagram of a closed Brayton cycle is shown in Fig. 4.3. 

The nuclear fuel cycle is a set of steps in the processing of the reactor s fissile materials that begins with the mining of uranium and extends through the final disposition of the waste from the reactor. These steps are referred to as a cycle because it is possible that the material taken from the reactor after use can be recycled. A schematic diagram of the nuclear fuel cycle is shown in Figure 16.1. 

FIGURE 17.25 A schematic diagram of one type of nuclear reactor. This one is a pressurized water reactor (PWR), in which the coolant is water under pressure. The fission reactions produce heat, which boils water in the steam generator the resulting steam turns the turbines that generate electricity. The water acts as a moderator. 

Figure 8.22 Schematic diagram of a nuclear gas cooled reactor showing the location of ion exchange treatments [From Amberlite Ion Exchange Resins in Nuclear Power Technology , Rohm and Haas (European Region)]...

Most commercial nuclear power plants in the United States are light water reactors, moderated and cooled by ordinary water. Figure 26-12 is a schematic diagram of a light water reactor plant. The reactor core at the left replaces the furnace in which coal, oil, or natural gas is burned in a fossil fuel plant. Such a fission reactor consists of five main components (1) fuel, (2) moderator, (3) control rods, (4) cooling system, and (5) shielding. 

Most of the nuclear reactors in the United States are light water reactors. Figure 23.10 is a schematic diagram of such a reactor, and Figure 23.11 shows the refueling process in the core of a nuclear reactor. 

FIGURE 23.10 Schematic diagram af a nuclear fissian reactor. The fission process is controlled by cadmium or boron rods. The heat generated by the process is used to produce steam for the generation of electricity via a heat exchange system. 

Another case of practical interest in nuclear engineering is the buildup and decay of fission products formed in a nuclear reactor operating at a steady fission rate for a time T and that have been removed from the reactor and aUowed to undergo radioactive decay for an additional time. The schematic diagram for continuous production of the first member of the drain at rate P is... 

Nuclear reactor. A schematic diagram of a gas-cooled reactor. 

In natural uranium ores, the fraction of the atoms of the fissile isotope is about 0.72%. For many commercial applications, like production of fuel for light water reactors or several types of research reactors and other nuclear functions, its fraction must be increased, that is, isotope enrichment is carried ont. The main isotope separation methods, or isotope enrichment processes, ntilize the small differences in between the mass of U-235 and U-238. The two major commercial methods that have supplied most of the enriched uranium to date, gaseous diffusion and gas centrifuges, use the only gaseous compound of nraninm, nranium hexafluoride (UFg), as the feed material. Both methods utilize the difference between the mass of UFg (349 Da) and UFg (352 Da) where the mass ratio difference that is 0.86%. The product and tails of the enrichment process are also with the same chemical form, but the isotope composition of the material is altered in the enrichment process. Schematic diagrams of the principle of operation of these methods can be found on the web and in many textbooks, so will not be shown here. 

Figure VIII-1 shows a simplified schematic diagram of the nuclear steam supply system with the Package-Reactor. The concept resembles a calandria-type pressurized heavy water reactor (e.g., the FUGEN advanced thermal reactor (ATR) or CANDU reactors) since all these employ pressure tubes. But the Package-Reactor is somewhat different from the ATR or the CANDU. The Package-Reactor employs natural circulation with two-phase flow for core cooling and has no recirculation pumps. The height of the pressure tubes of the cassettes is required to be as low as possible to attain a compact unit. Two-phase flow with high void fractions similar to BWRs is adopted to attain natural circulation with a cassette height of 6 m and a fuel rod length of 3.65 m.

Figure 1-2 shows the simplified schematic diagram of the SMART nuclear steam supply system (NSSS) and exhibits the safety systems and the primary system as well as auxiliary systems. The engineered safety systems designed to function passively on demand consist of a reactor shutdown system, passive residual heat removal system, emergency core cooling system, safeguard vessel and reactor overpressure protection system. 

A vertical cross-section of the CCR reactor and a simplified schematic diagram of the CCR based nuclear power plant are shown in Figures IX-1 and IX- 2 respectively. 

A vertical cross-sectional view of the AHWR reactor block is shown in Fig. XI-1, and a simplified schematic diagram of the AHWR based nuclear power plant is given in Fig. XI- 2. 

In the frame of the programme of the IAEA coordinated research on nuclear desalination in 1999-2000, NIKIET specialists have performed activities on the following subject, Application of Russian small size reactors as the energy source for nuclear desalination facilities (NDF) Optimization of the reactor interfaces with desalination plants, the performance and economic indices of NDF . In particular, proposals have been made with regard to using the RUT A as a source of heat for evaporation based desalination plants the schematic diagram of the reactor and desalination equipment interface has been developed and the economic evaluation of the NDF RUTA has been performed based on the desalination economic evaluation program (DEEP). 

The basic function of the main heat transport system is to remove nuclear heat generated in the fuel elements of the active core and blankets by heavy metal coolant in natural circulation, driven by the gas lift system in all modes of operation, i.e. under normal reactor operation and accident conditions. Figure XXIII-13 shows the schematic diagram of heat removal paths under normal operation and in accidents. 

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