Fissionable, definition

It is recommended that the convention used by Budzikiewicz, Djerassi, and Williams (Mass Spectrometry of Organic Compounds, Holden-Day, 1967, p. 2) be followed in referring to a-cleavage as fission of a bond originating at an atom which is adjacent to the one assumed to bear the charge the definition of p-, y-, then follows automatically. The process ... 

The material is arranged as follows. Photochemical reactions are discussed first (Section VI,A) as they represent the most thoroughly studied and only definitely established examples of the simplest type of reaction, viz., the homolytic fission of the Co—C bond. Thermal (i.e., nonphotochemical)... 

You can distinguish fission and fusion reactions from one another with a simple glance at products and reactants. If the reaction shows one large nucleus splitting into two smaller nuclei, then it s most certainly fission, whereas a reaction showing two small nuclei combining to make a single heavier nucleus is definitely fusion. 

High-level waste thus includes the concentrated wastes that arise from reprocessing of commercial or defense nuclear fuel that contain virtually all the fission products and transuranium radionuclides (except plutonium) in spent fuel. However, the definition does not mention the constituents of the waste, and it is only qualitative because concentrated is not quantified and the minimum fuel burnup that would yield high-level waste is not specified. Although the definition given above referred only to liquid (aqueous) waste, it is clear from further discussions in 10 CFR Part 50, Appendix F (AEC, 1970), that AEC intended that high-level waste also would include concentrated solid waste derived from liquid high-level waste that was suitable for permanent disposal. 

The definition of high-level waste in Clause (A) of NWPA given above follows the traditional, source-based description although, for the first time, the presence of fission products is mentioned explicitly. However, the definition remains qualitative because highly radioactive material and sufficient concentrations of fission products are not quantified, nor are the minimum concentrations of alpha-emitting transuranium radionuclides. 

This definition is based on the source of the waste, but certain incidental wastes that arise from fuel reprocessing that contain lower concentrations of fission products and alpha-emitting transuranium radionuclides than the primary reprocessing wastes have been excluded on a case-by-case basis. 

Although this definition specifies a lower limit on the concentration of particular radionuclides, it also depends on the qualitative, source-based definition of high-level waste and, thus, is not strictly quantitative. Alpha-emitting transuranium radionuclides with half-lives greater than 20 y are expected to be the principal constituents of most transuranic waste, but the definition does not specify any limits on the concentrations of other radionuclides that may occur in transuranic waste, including fission products, alpha-emitting nontransuranium radionuclides, and alpha-emitting transuranium radionuclides with half-lives less than 20 y. 

DOE has defined low-level waste as in Clause (A) above (DOE, 1988c 1999c). In the earlier definition (DOE, 1988c), test specimens of fissionable material irradiated for purposes of research and development could be classified as low-level waste, provided the concentration of long-lived, alpha-emitting transuranium radionuclides was... 

The initial decomposition chemistry involves unimolecular reactions. This was the conclusion of the first gas-phase kinetics study [84] and has been repeatedly confirmed by subsequent bulb and shock-tube experiments [85, 86]. That first study used shock heating to induce thermal decomposition [84], The data were interpreted in terms of simple C-N bond fission to give CH2 and N02. A more extensive and definitive shock-tube study was reported by Zhang and Bauer in 1997 [85]. Zhang and Bauer presented a detailed kinetics model based on 99 chemical reactions that reproduced their own data and that of other shock-tube experiments [84, 86]. An interesting conclusion is that about 40% of the nitromethane is lost in secondary reactions. 

More definitions are necessary to attempt this sort of optimization Potential californium is a measure of the maximum amount of californium that can be produced from a given batch of feed, taking into account the fact that many atoms undergo fission along the path from feed to product. The efficiency of a particular irradiation is the amount of californium produced divided by the amount of potential californium consumed in the irradiation and subsequent processing. This efficiency measure takes into consideration the destruction of the 2 2Cf by decay and neutron capture and processing losses of all the nuclides in the chain. 

Colorless deoxyvomicine is reduced by allylic fission, together with reduction of the 12,13-double bond, to give F (CCLXXIV). Without definite experimental evidence, Huisgen claims F and C to be C-13 epimers. Further reduction gives bases G and H (CCLXXV), epimeric at C-21, and stereoisomeric with bases D and E (CCLXXIII). 

On account of this element s rarity, a separate account of it is desirable. Although the existence of promethium was predicted as early as 1913, it was not definitely discovered until 1945, since all isotopes are radioactive with the longest-lived isotope having a half-life of 17.7 years ( " Pm). It is a fission product of and is thus obtained on work-up of reprocessing wastes. 

Special fissionable materials which fall within the definition of nuclear-weapon-usable materials are prohibited. 

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