Of plutonium metal

Fig. 1. Piessuie—volume—tempeiatuie phase diagram of plutonium metal (35). To convert MPa to atm, multiply by 9.9.

Table 6. Phase Relationships and Crystallographic Properties of Plutonium Metal ...

Fig. 2. Electrical resistivity, R, of plutonium metal, plotted as 100 R/R y versus absolute temperature (47).

Fig. 3. Magnetic susceptibility of plutonium metal as a function of temperature where represent initially high density plutonium and , cast plutonium...

The corrosion behavior of plutonium metal has been summarized (60,61). a-Plutonium oxidizes very slowly in dry air, typically <10 mm/yr. The rate is accelerated by water vapor. Thus, a bright metal surface tarnishes rapidly in normal environments and a powdery surface soon forms. Eventually green PUO2 [12059-95-9] covers the surface. Plutonium is similar to uranium with respect to corrosion characteristics. The stabilization of 5-Pu confers substantial corrosion resistance to Pu in the same way that stabilization of y-U yields a more corrosion-resistant metal. The reaction of Pu metal with Hquid water produces both oxides and oxide-hydrides (62). The reaction with water vapor above 100°C also produces oxides and hydride (63). 

Preparation of Plutonium Metal from Fluorides. Plutonium fluoride, PuF or PuF, is reduced to the metal with calcium (31). Although the reactions of Ca with both fluorides are exothermic, iodine is added to provide additional heat. The thermodynamics of the process have been described (133). The purity of production-grade Pu metal by this method is ca 99.87 wt % (134). Metal of greater than 99.99 wt % purity can be produced by electrorefining, which is appHcable for Pu alloys as well as to purify Pu metal. The electrorefining has been conducted at 740°C in a NaCl—KCl electrolyte containing PuCl [13569-62-5], PuF, or PuF. Processing was done routinely on a 4-kg Pu batch basis (135). 

The first definite production of plutonium metal was made in November, 1943 by Baumbach and coworkers (1958). Approximately 35 micrograms of PuFi in a small thoria crucible in a high vacuum was reacted with barium metal at 1400 C to yield plutonium metal. The metal was found to have a silvery lustre, a density of about 16 grams j>er cubic centimeter and it rapidly absorbed hydrogen at about 210 C to form a black powder subsequently identified as PUH3 (a proof that metal had been produced). 

P. L. 1958. The microscale preparation and micrometallurgy of plutonium metal. J. Inorg. Nucl. Chem. 5, 182-189. 

A production process has evolved from this original work, and is presently used for extracting americium from kilogram amounts of plutonium metal. This process is based upon equilibrium partitioning (by oxidation-reduction reactions) of americium and plutonium between the molten chloride salt and the molten plutonium phase. The chemistry of this process is indicated by the following reactions ... 

Schweikhardt, R.D. "Metal-Salt Reactions in Molten Systems of Plutonium Metal and NaCl, NaCl-KCl, and NaCl-KCl-MgCl2" thesis, Univ. of Denver, August 1966. 

Mullins, L.J. Morgan, A.M. Apgar, S.A. Ill and Christensen, D.C. "Six-Kilogram Scale Electrorefining of Plutonium Metal", Los Alamos National Laboratory Report LA-9469-MS (1982). 

The production of plutonium metal by both fluoride and oxide reduction is well established at Los Alamos. The subsequent purification of this metal by electrorefining is now being performed in production on a 6-kg batch scale. The objective is the production of high-purity plutonium metal. 

Baker, R. D. "Preparation of Plutonium Metal by the Bomb Method," Los Alamos Scientific Laboratory, LA-473 (1946). 

Sohn, C. L. Thorn, C. W. Christensen, D. C. "Enchanced Production of Plutonium Metal Using Pu02 in the PuF4/Bomb Reduction Process," Los Alamos National Laboratory LA-UR-82-1230, May 1982. 

The reaction of plutonium metal with N2 in a sputtering device 41) resulted in the observation of matrix-isolated, plutonium nitride species. The species observed were PuN and PUN2, the latter being a linear species. 

Helgeson, G.L., Further Notes on the Surface Dosage of Plutonium Metal, HW-41369, General Electric Company, Richland, WA, 1956. 

Line III has a great interest, because it takes into account in the case of U partial localization effects of 5f states. Such partial localization effects, if present in uranium metal, should be even more visible in the emission of plutonium metal. For this reason, line III will be discussed after the analysis of the valence band spectrum of plutonium metal. 

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