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Spent fuel heat production

Figure 11.19. /S activity and heat production of spent fuel as a function of the time after shutting off the reactor. (The y activity amounts to about half of the / activity the heat production is calculated for an average jS energy of 0.4 MeV and quantitative absorption.)... Figure 11.19. /S activity and heat production of spent fuel as a function of the time after shutting off the reactor. (The y activity amounts to about half of the / activity the heat production is calculated for an average jS energy of 0.4 MeV and quantitative absorption.)...
The classical Purex process was designed to produce nearly pure uranium and plutonium. The Chemical Engineering Division of Argonne National Laboratory has demonstrated UREX+, an advanced aqueous process with five extraction trains that split commercial reactor spent fuel into five streams 1) a nearly pure uranium stream (95.5% of the heavy metal in the spent fuel) 2) technetium sent to transmutation (0.08 /o) 3) Pu/Np converted to MOX fuel for LWR fuel and Am/Cm for transmutation or fast-flux reactor fuel (0.962 /o) 4) Cs/Sb decay heat producers sent to interim decay storage (0.017 /o) and 5) a mixed fission product stream (3.44 /o) composed of gases and solids incorporated into a waste form for geological repository disposal.f The percentages shown are computed from Table 1. [Pg.2652]

The decay heat is considerable at short cooling times due to the very high decay rate (see Fig. 19. IS). Before unloading spent fuel from a reactor, the used fuel elem ts are first allowed to cool in the reactor by forced circulation. Within a few weeks they are th transferred under water to the cooling basin at the reactor site for an additional cooling time, usually 6—12 months, after which they may be transferred to a central spent fuel storage facility. In the absence of such facilities, sp it fuel elemrats can be stored in the reactor pools for many years. During this time the radiation level and heat production decrease considerably. [Pg.599]

With a typical heat production of 500 W per canister containing vitrifled HAW (at 40 years cooling) the wall heat daisity would be 6-7 W m. The internal tenq>erature of a glass canister would then never exceed 90°C, and the surface temperature (above the storage holes, Fig. 21.24) not more than 6S°C. Slightly higher temperatures can be accepted for spent fuel elements. [Pg.634]

The accuracy of decay heat calculations depends on the individual heat generation rate from fission product decay nuclides and actinides, and the burnup calculation for its production and transmutation. To obtain experimental data and to improve the accuracy of related calculations, the decay heat of MK-II spent fuel subassemblies was measured at the JOYO spent fuel storage pond [7], The fuel burnup was approximately 66 GWd/t and the cooling time was between 40 and 385 days. The measured decay heat is shown in Fig. 9. [Pg.38]

Spent fuel cooling is necessary in order to remove the heat produced by the decay of the unstable fission products accumulated within the fuel element, which is a result of the fission process. Removal of the decay heat is necessary to avoid any possible spent fuel blistering, which could arise if the spent fuel were not properly cooled. Moreover, it allows for a sufficient cooling-off period before any transfer of the spent fuel to an away-from-reactor site, if needed. [Pg.84]

If spent fuel is declared as waste, spent fuel is solid HLW but including some volatile fission products in the fuel rods. The specific activity of spent fuel is very high after five years cooling time UOj-fuel exhibits typically a specific total activity of 2.5 10 TBq/tHM. Mixed oxide fuel has nearly the same specific fission product activity as U02-fuel (1.8 T0 TBq/tHM), but a considerably higher activity of actinides (2.8 T0 TBq/tHM). The specific activity is dependent on cooling time and bumup. In recent years there has been a steady increase of the bumup. Typical rates of heat generation are 2-4 kW/tHM after five years of cooling. [Pg.122]

U will only be possible through isotope separation techniques. The high Pu to Pu ratio and the production of gamma emitting Tl in the thorium cycle are hindrances to nuclear proliferation. Pu has a spontaneous fission that contributes to increased residual heat of spent fuel that will complicate the production of nuclear weapons. [Pg.380]

Ucon HTF-500. Union Carbide Corp. manufactures Ucon HTE-500, a polyalkylene glycol suitable for Hquid-phase heat transfer. The fluid exhibits good thermal stabHity in the recommended temperature range and is inhibited against oxidation. The products of decomposition are soluble and viscosity increases as decomposition proceeds. The vapor pressure of the fluid is negligible and it is not feasible to recover the used fluid by distiHation. Also, because the degradation products are soluble in the fluid, it is not possible to remove them by filtration any spent fluid usuaHy must be burned as fuel or discarded. The fluid is soluble in water. [Pg.504]

Thermal decomposition of spent acids, eg, sulfuric acid, is required as an intermediate step at temperatures sufficientiy high to completely consume the organic contaminants by combustion temperatures above 1000°C are required. Concentrated acid can be made from the sulfur oxides. Spent acid is sprayed into a vertical combustion chamber, where the energy required to heat and vaporize the feed and support these endothermic reactions is suppHed by complete combustion of fuel oil plus added sulfur, if further acid production is desired. High feed rates of up to 30 t/d of uniform spent acid droplets are attained with a single rotary atomizer and decomposition rates of ca 400 t/d are possible (98). [Pg.525]


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Fuel production

Fuel products

Heat production

Heating fuel

Spent fuel

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