Breeder blanket

The effect of poisoning can be compensated to a certain extent by an excess reactivity or by installation of a breeder blanket (an outer layer of Th) in which new fissile material is produced. In fast reactors the effect of poisoning is less important. 

The unusual interaction of hydrogen with palladium-based membrane materials opens up the possibility of oxidative hydrogen pump for tritium recovery from breeder blankets. The feasibility for this potential commercial application hinges on the hot-fusion and cold-fusion technology under development [Saracco and Specchia, 1994]. At first, Yoshida et al. [1983] suggested membrane separation of this radioactive isotope of hydrogen followed by its oxidation to form water. Subsequently, Hsu and Bauxbaum [1986] and Drioli et al. [1990] successfully tested the concept of combining the separation and reaction steps into a membrane reactor operation. 

N.Sakamoto, S.Saito, M.Kato, R.Solomon and H.Kawamura, to be published in Proc. 5th international workshop on Ceramic Breeder Blanket Interaction, Rome, September 23-25, 1996. 

Another emerging application of the membrane assisted WGS concept (WGS-MR) is a process to recover tritium from tritiated water from breeder-blanket fluids in fusion reactor systems. A conceptual process model to accomplish this has been proposed by Violante et al. [2.435]. It uses two membrane reactor units. The first membrane reactor unit removes the hydrogen isotopes from the purge gas (He) via oxidation. The second unit uses the tritiated water to recover tritium using the WGS reaction. In a companion... 

D5. Dwyer, 0. E., et al. High-Temperature Processing Systems for Liquid-Metal Fuels and Breeder Blankets, PICGfl) 9 604 (1956). 

Buxbaum RE. The use of zirconium-palladium windows for the separation of tritium from the liquid metal breeder-blanket of a fosion reactor. Sep Sci Technol. 1983 8(12-13) 1251. Buxbaum RE, Hsu PC. Method for plating palladium. US Patent 5149420,1992. 

Two design options are considered for the reactor core a conventional homogoteous core and an axial heterogeneous core with an internal fertile slice just below core midplane. Both concepts (see Figio) have three core zones with different plutonium contents and are fully compatible with each other. The core is surrounded by one row of breeder subassemblies and an axial breeder blanket located above and below core. 

Fusion reactor materials (e.g., blanket testing, first wall materials, plasma facing materials, windows for microwave heating systems, breeder blanket materials). 

X (x = H or D). Such a result should be extrapolated to lithium-tritide solutions. In the same way Buxbaum (1982) have used yttrium for the separation of tritium from the liquid lithium breeder-blanket of a fusion reactor. 

Protactinium. No efforts have been made to achieve high solubilities of protactinium in order to use it as a component of reactor fuel solutions. Rather, the chemistry of protactinium has been examined in order to devise processes for removing Pa continuously from thorium breeder blanket systems. A project was undertaken by the Mound Laboratories [28] to separate gram quantities of the longer-lived Pa which could be used in studies of the chemistry of protactinium. 

M. H. Lietzke and W. L. Marshall, Present Status of the Investigation of Aqueous Solutions Suitable for Use in a Thorium Breeder Blanket, USAEC Report ORNL-1711, Oak Ridge National Laboratory, June 1954. 

P. G. Jones and R. G. Sowden, Thorium Nitrate Solution as a Breeder Blanket in the H.A.R., Report AERE-C/M-298, Part I. Thermal Stability, Gt. Brit. Atomic Energy Research Establishment, 1956. 

R.. 1. Tkitel et al., Liquid-AIetal Fuels and Liquid-AIetal Breeder Blankets, ibid., No. 13. (p. 11)... 

The problem of TliBi2 deposition during circulation through a temperature differential is one which must be solved before the Th-Bi slurry is acceptable as a fluid breeder-blanket material. The favorable results obtained by tellurium additions in the capsule experiments offer hope that the problem can be solved. 

Fig. 22-11. Flow diagram for processing a 10 w/o Th-Bi breeder-blanket slurry to remove Pa and...

A potential application of the WGS reaction carried out in an MR is represented by the tritium recovery process from tritiated water from breeder blanket fluids in fusion reactor systems. The hydrogen isotopes separation at low concentration in gaseous mixtures is a typical problem of the fusion reactor fuel cycle. In fact, the tritium produced in the breeder needs a proper extraction process to reach the required purity level. Yoshida et al. (1984) carried out experimental and theoretical studies of a catalytic reduction method which allows tritium recovery from tritiated water with a high conversion value (> 99.99%) at a relatively low temperature, while Hsu and Buxbaum (1986) studied a palladium-catalysed oxidative diffusion... 

---