A proposed means of transmuting key long-lived radioactive isotopes, primarily the socalled minor actinides (Np, Am, Cm), using a hybrid proton-accelerator-sub-critical lattice, is described. It is argued that by partitioning the components of the light water reactor (LWR) spent fuel and by transmuting key elements, such as the plutonium, the minor actinides, and a few of the long-lived fission products, that some of the most significant challenges in building a waste repository can be substantially reduced. If spent fuel partitioning and transmutation were fully implemented, the time required to reduce the waste stream toxicity below that of uranium ore would be reduced from more than 10,000 years to approximately 30 years. The proposed machine, based on the described PHOENIX Concept, would transmute the minor actinides and much of the iodine produced by 75 LWRs, and would generate usable electricity (beyond that required to run the large accelerator) of 850 MW g . iii EXECUTIVE SUMMARYThe PHOENIX Concept uses a large linear proton accelerator to drive and control one or more subcritical lattices of minor actinides (Np, Am, Cm), to transmute the long-lived radioactive wastes from light-water reactors that are the most difficult to dispose of, and to produce electric power in the process. One 3600 MWj. machine would transmute the neptunium, americium, curium, and much of the iodine produced by about 75 light water reactors (LWRs), and would generate a net of about 850 MW g for the electrical grid.While not tied to a specific fuel reprocessing/recycling technology, much of the PHOENIX analysis performed thus far has been based on Westinghouse Hanford's proposed CURE approach, which is a waste partitioning process based on the well known PUREX process and the newer TRUEX process. Within the CURE framework, certain elements are to be recycled, transmuted, or simply separated from the major portion of the high-level wastes. The primary objective is to eliminate certain problem components from the bulk of the spent fuel so that the remainder can be packaged more easily (reduced heat load and shorter life-time requirements) for disposal in the geologic repository currently planned by DOE. In principle, the toxicity of the LWR waste stream could be reduced below that of naturally occurring uranium ore within a few decades (-30 years), as opposed to more than 10,000 years if unprocessed. Of the key long-lived elements to be isolated, several, including the uranium, plutonium, and technetium, could be either recycled into current or future reactors, or packaged separately for burial in the repository. The elements that would be most difficult to consume in LWRs, namely the minor actinides and the iodine, could be transmuted in PHOENIX with a high degree of safety and efficiency. In particular, the safety advantage comes from always running the machine subcritical, thereby making reactivity accidents insignificant, and the efficiency advantage comes from eliminating the need for uranium or plutonium feed, because the a...
powerful in adding to the corrosion resistance of a glass and that borosilicate glasses of the type considered are inherently of good chemical durability. The actual results of averaged check measurements were as follows: ZrOa in glass Naz0 extracted (%) (%f 0 0.009 1 .004 2 .003 4 .002It is worth noting that small amounts of conia have a decided influence and that as zirthe amount is increased the rate of improvement seems to be proportionally smaller. As an approach is made nearer and nearer to "zero" solubility, however, it is natural that the percentage effect on the alkali extracted should appear to be less. The picture may be more readily grasped by plotting the percentage of zirconia against the reciprocal of the percentage of alkali extracted. This reciprocal might be termed the ''resistance to corrosion" and would become infinite, of course, when the amount of alkali extracted became zero. Figure 1 illustrates the effect on the "resistance" of the replacement of alumina by zirconia and indicates that the increase in resistance is a reasonably progressive and regular one.There is the possibility, of course, that in addition to the alkali some boric oxide is also ex-/ 2 3 4 * -% Zr@ sub.dihJkd I % ~4 4 FIG. 1.-Effect on resistance to attack of substituting ZrOz for AlaOa in glasses studied.tracted from the glass in the determination of durability by the method described herein and might have some influence on the results. Such tests as have been made did not indicate that this was a disturbing factor, but measurements are being made by other methods to confirm this. ABSTRACTMeasurements of the moduli of elasticity and of rigidity were made on four sodaBoth moduli are lowered by the substitution of ZrOz lime glasses containing ZrOz. for CaO
This is a report on the microstructure of mats found in the following composition range: These were fired at cones 03, 2, 4, and 6. The compounds present recognized as crystals were anorthite, cession (probably), tridymite, and wollastonite. Willemite was not observed. The good mats were due to crystal separations. A high alumina content was not essential. Anorthite was the principal crystalline form present in mat glazes containing lime.
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