Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Blanket processing, plutonium

When the fuel is initially loaded into die reactor, the core region will typically contain from 10 to 15% fissile isotopes with the remainder being ijSU. Essentially all of the blanket will be 238U. As energy is extracted from the fissile isotopes, they become depleted (the initial plutonium is gradually used up), However, in a breeder reactor, new plutonium will be formed in die cure and blanket regions faster Ilian it is consumed. Additionally, undesirable fission products are formed which must ultimately be removed. This process is schematically illustrated in Fig. 31. The before chart... [Pg.1117]

In tlie PUREX process, the spent fuel and blanket materials are dissolved in nitric acid to form nitrates of plutonium and uranium. These are separated chemically from the other fission products, including the highly radioactive actinides, and then the two nitrates are separated into tv/o streams of partially purified plutonium and uranium. Additional processing will yield whatever purity of the two elements is desired. The process yields purified plutonium, purified uranium, and high-level wastes. See also Radioactive Wastes in the entry1 on Nuclear Power Technology. Because of the yield of purified plutonium, the PUREX process is most undesirable from a nuclear weapons proliferation standpoint,... [Pg.1647]

The fast breeder reactor cycle in this cycle, the spent fuel is similarly reprocessed and the uranium and plutonium fabricated into new fuel elements. However, they are recycled to fast breeder reactors, in which there is a central core of uranium/plutonium fuel surrounded by a blanket of depleted uranium (uranium from which most of the uranium-235 atoms have been removed during the process of enrichment) or to burner reactors. This depleted uranium consists mostly of uranium-238 atoms, some of which are converted to plutonium during irradiation. By suitable operation, fast breeder reactors thus can produce slightly more fuel than they consume, hence the name breeder (see Fig. 7.1). [Pg.307]

The present work at Rocky Flats is an extension of the Argonne work and is directed to development of a proliferation resistant pyrochemical process for LMFBR fuels. This article describes a conceptual pyrochemical process and preliminary engineering concepts for coprocessing uranium and plutonium in spent LMFBR core-axial blanket and radial blanket fuels using the Salt Transport Process. [Pg.185]

Fuel composition may change from uranium to plutonium, and cladding from aluminum to zirconium to stainless steel. In some cases blankets, moderators, and coolants must be processed, and these will introduce thorium, beryllium, NaK, and bismuth to the chemical process. These changes in materials will present new chemical and corrosion problems in waste treatment processes and waste storage procedures. [Pg.114]

Fractional crystallization. Volatile metals with much lower boiling points than uranium, such as magnesium (1103°C), zinc (906°C), and cadmium (767°C), have been extensively studied as solvents for separating constituents of irradiated metal fuel by fractional crystallization, followed by evaporation of the solvent metal from the separated fractions. For example, in liquid magnesium, the solubility of plutonium or thorium is high, but uranium is very low. A process of this type was developed at Argonne National Laboratory [P6] for concentrating plutonium in the uranium metal blanket of a breeder reactor from 1 percent to 40 percent. [Pg.463]

In Fig. 10.28 it is assumed that assemblies from the core and radial blanket are reprocessed in the proportion in which they are discharged from the reactor. The average composition of feed to the reprocessing plant then is 10 w/o plutonium, 3.56 w/o flssion products, and 86.44 w/o uranium. The 5000 kg of fuel processed per day is associated with 6858 kg of stainless steel and an indeterminate amount of metMlic sodium that coats exterior surfaces of the assembly and possibly has penetrated imperfections in some of the fuel rods. Sodium is used as... [Pg.530]

Would moderate the neutrons, and so a liquid metal, usually sodium, is used. The core is surroimded by a blanket of uranium-238 that captures neutrons that escape the core, producing plutonium-239 in the process. The plutonium can later be separated by reprocessing and used as fuel in a future cy cle. [Pg.901]

A fast breeder reactor offers one approach to getting more power out of existing uranium sources and potentially reducing radioactive weiste. This type of reactor is so named because it creates ( breeds ) more fissionable material than it consiunes. The reactor operates without a moderator, which means the neutrons used are not slowed down. In order to capture the fast neutrons, the fuel must be highly enriched with both uranium-235 and plutonium-239. Water cannot be used as a primary coolant because it would moderate the neutrons, and so a hquid metal, usually sodimn, is used. The core is surrounded by a blanket of iucmium-238 that captmes neutrons that escape the core, producing plutonium-239 in the process. The plutonium can later be separated by reprocessing and used as fuel in a future cycle. [Pg.937]

Pu- are considered. Fuel is removed and processed at a rate required to maintain a specified poison level. The reactor consists of a core region in which plutonium is burned and of a blanket region containing uranium and plutonium. Under equilibrium conditions the net rate of production of plutonium in the blanket is eipial to the plutonium consumption in the core, in Table 2-11 are given [2D] some of the nuclear characteristics for... [Pg.57]

Neptunium and protactinium complete the listing of fissile and fertile materials, since these are intermediates in the production of plutonium and U233 from XJ238 thorium. Limited exploratory studies of their solubilities have been carried out primarily in connection with the development of processes for their continuous removal from blanket systems. [Pg.87]

Plutonium. A considerable investigation of the chemistry of plutonium in aqueous uranyl sulfate solutions has been directed, not toward the achievement of solubility, but toward the achievement of insolubility in order to provide the basis for continuous processing of a blanket solution for plutonium production [25] (see Chapter 6). [Pg.99]

Fig. 6-3. Conceptual flow diagram for processing blanket material from a two-region plutonium producer. Fig. 6-3. Conceptual flow diagram for processing blanket material from a two-region plutonium producer.
In a power-converter the plutonium is extracted from the blanket and fed to the core as fuel material. Natural uranium is fed to the blanket, and the plutonium formed is extracted by Purex processing. By adjusting the concentrations of fissionable materials in the blanket, the net rate of production of plutonium in the blanket is made equal to the consumption in the core. The fuel cycle considered for a two-region reactor is shown in Fig. 10-7. Plutonium from the core is processed continuou.sly through a... [Pg.536]


See other pages where Blanket processing, plutonium is mentioned: [Pg.330]    [Pg.15]    [Pg.39]    [Pg.1647]    [Pg.885]    [Pg.885]    [Pg.173]    [Pg.181]    [Pg.201]    [Pg.268]    [Pg.13]    [Pg.151]    [Pg.532]    [Pg.7030]    [Pg.2722]    [Pg.504]    [Pg.16]    [Pg.13]    [Pg.303]    [Pg.318]    [Pg.326]    [Pg.537]    [Pg.592]   


SEARCH



Blanketing

Plutonium processing

Plutonium processing processes

© 2024 chempedia.info